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Wyświetlanie 1-42 z 42
Tytuł:
Gender differences of managing banks’ credit portfolio
Różnice płci w zarządzaniu portfelem kredytowym banków
Autorzy:
Rózsa, Z.
Zbranková, H.
Rahman, A.
Powiązania:
https://bibliotekanauki.pl/articles/406040.pdf
Data publikacji:
2018
Wydawca:
Politechnika Częstochowska
Tematy:
credit risk management
gender
ethics
behaviour
banks
zarządzanie ryzykiem kredytowym
płeć
etyka
zachowanie
banki
Opis:
The article aimed to demonstrate whether the quality of decision-making on lending to clients in the small and medium-sized business sector is influenced by the gender of the approvers or their direct motivation caused by share on business results. The motivation for this research were the studies conducted after the last global financial crisis, mostly in the US and Europe, to a lesser extent in the Czech Republic. Their authors tend to conclude that women show better credit risk management than men and that direct managers’ engagement in business results and profits generates a higher susceptibility to risky, erroneous decisions. The research was carried out on one of the major banks operating in the Czech Republic, on a nationwide sample of workers with the loan approval authority in the segment of small and medium-sized firms. The decision of the approvers was, based on a random selection of about 1/3 of all their decisions, subject to control over three consecutive years. The obtained data were analysed by ANOVA, which did not prove the dependence of the decision quality on the gender or the direct motivation of the approver on business results. The research and its results have opened up scope for further research on the issue with a focus on a qualitative analysis of the nature and severity of the mistakes in terms of gender, job position, the level of authorization power and, last but not least, the unequal representation of women in the management of domestic banks.
Artykuł miał na celu wykazanie, czy na jakość procesu decyzyjnego w zakresie udzielania kredytów klientom w sektorze małych i średnich przedsiębiorstw wpływa płeć osób zatwierdzających lub ich bezpośrednia motywacja spowodowana udziałem w wynikach biznesowych. Motywacją do tych badań były badania przeprowadzone po ostatnim światowym kryzysie finansowym, głównie w USA i Europie, w mniejszym stopniu w Czechach. Ich autorzy mają tendencję do stwierdzenia, że kobiety wykazują lepsze zarządzanie ryzykiem kredytowym niż mężczyźni i że bezpośrednie zaangażowanie menedżerów w wyniki biznesowe i zyski generuje wyższą podatność na ryzykowne, błędne decyzje. Badania przeprowadzono w jednym z największych banków działających w Republice Czeskiej, w ogólnokrajowej próbie pracowników z organem zatwierdzającym pożyczki w segmencie małych i średnich firm. Decyzja osób zatwierdzających była oparta na losowej selekcji około 1/3 wszystkich decyzji, podlegających kontroli przez trzy kolejne lata. Uzyskane dane zostały przeanalizowane przez ANOVA, która nie wykazała zależności jakości decyzji od płci ani bezpośredniej motywacji osoby zatwierdzającej do wyników biznesowych. Badania i ich wyniki otworzyły możliwości dalszych badań w tym zakresie, koncentrując się na jakościowej analizie charakteru i wagi błędów pod względem płci, stanowiska pracy, poziomu uprawnień do autoryzacji oraz, co nie mniej ważne, nierówna reprezentacja kobiet w zarządzaniu bankami krajowymi.
Źródło:
Polish Journal of Management Studies; 2018, 18, 2; 272-283
2081-7452
Pojawia się w:
Polish Journal of Management Studies
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Properties of~Rf Plasma Nitrided Silicon Thin Films at Different Rf Plasma Processing Powers
Autorzy:
Mohamed, S.
Raaif, M.
Abd El-Rahman, A.
Shaaban, E.
Powiązania:
https://bibliotekanauki.pl/articles/1493713.pdf
Data publikacji:
2011-09
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
81.15.Dj
61.05.cp
73.61.-r
78.66.-w
Opis:
Nitrided surfaces and composition gradients in thin films exhibit interesting mechanical, electrical and optical properties. Therefore, silicon (Si) thin films were prepared by electron beam evaporation and nitrided by an inductively coupled rf plasma. The effects of successive plasma processing power on structural and optical properties as well as electrical resistivity were examined by different characterization techniques. The Si thin films were transformed gradually into nitrides compound thin films and the amount of nitrogen in the film increased with increasing the rf processing power. The Si nitrided films showed structural, optical and electrical properties that depend on the nitriding power. Increasing the rf plasma processing power caused amorphization, reduced the thickness, increased transmittance, increased resistivity and decreased the reflectance of the Si films. The electrical resistivity increased about eight orders of magnitude when the sample nitrided at 500 W. Different optical band gap were determined indicating the presence of different competing phases in the same film. The decrease in refractive index with plasma treatment power is attributed to the possible change in the bucking density as well as to the increase in the band gap.
Źródło:
Acta Physica Polonica A; 2011, 120, 3; 552-557
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
EDTA reduces cadmium toxicity in mustard (Brassica juncea L.) by enhancing metal chelation, antioxidant defense and glyoxalase systems
EDTA obniża toksyczność kadmu w gorczycy sarepskiej (Brassica juncea L.) poprzez zwiększenie chelatowania metalu oraz poprawę działania systemu antyoksydacyjnego i glioksalazowego
Autorzy:
Al Mahmud, J.
Hasanuzzaman, M.
Nahar, K.
Rahman, A.
Fujita, M.
Powiązania:
https://bibliotekanauki.pl/articles/27056.pdf
Data publikacji:
2019
Wydawca:
Polskie Towarzystwo Botaniczne
Opis:
To investigate the possible role of EDTA in mitigating cadmium (Cd) toxicity, we treated mustard (Brassica juncea L.) seedlings with CdCl2 (0.5 mM and 1.0 mM, 3 days) alone and in combination with 0.5 mM EDTA in a semihydroponic medium. In the absence of EDTA, mustard seedlings accumulated Cd in their roots and shoots in a concentration dependent manner. Overaccumulation of Cd boosted generation of hydrogen peroxide (H2O2) and superoxide anions (O2•−), increased lipoxygenase (LOX) activity, lipid peroxidation, and cytotoxic methylglyoxal (MG) content. It also disturbed components of the antioxidant defense and glyoxalase systems. Furthermore, Cd stress decreased growth, leaf relative water content (RWC) and chlorophyll (chl) content but augmented the proline (Pro) content. On the other hand, EDTA supplemented Cd-stressed seedlings improved the constituents of the AsA-GSH cycle with the upregulated activities of ascorbate peroxidase (APX), monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR), glutathione reductase (GR), glutathione peroxidase (GPX), superoxide dismutase (SOD), and catalase (CAT). Moreover, addition of EDTA to the Cd-stressed seedlings notably enhanced Gly I activity in contrast to the stress treatment. Ethylenediaminetetraacetic acid decreased Cd accumulation in the both shoots and roots, as well as increased other nonprotein thiols (NPTs) in leaves, including the phytochelatin (PC) content. It also decreased H2O2 and O2•− generation, lipid peroxidation and MG content but enhanced RWC, chl and Pro contents in the leaves, which confirmed the improved growth of seedlings. The findings of the study suggest that exogenous application of EDTA to the Cd-treated seedlings reduces Cd-induced oxidative injuries by restricting Cd uptake, increasing NPTs concentration and upregulating most of the components of their antioxidant defense and glyoxalase systems.
W celu określenia roli EDTA (kwas edetynowy, acidum edeticum) w obniżaniu toksyczności kadmu (Cd), siewki gorczycy (Brassica juncea L.) traktowano CdCl2 (w stężeniach 0,5 i 1 mM przez 3 dni) w kombinacjach z lub bez dodatku 0,5 mM EDTA do semi-hydroponicznego podłoża. Rośliny uprawiane w obecności Cd bez EDTA akumulowały metal w korzeniach i częściach nadziemnych proporcjonalnie do zastosowanego stężenia Cd. Akumulacja Cd indukowała produkcję nadtlenku wodoru (H2O2) i anionu ponadtlenkowego (O2•−), zwiększała aktywność lipoksygenazy (LOX), peroksydację lipidów i poziom cytotoksycznego metyloglioksalu (MG). Kadm zakłócał również funkcjonowanie składników systemu antyoksydacyjnego i glioksalazowego. Ponadto, Cd negatywnie wpływał na wzrost roślin, względną zawartość wody w liściach (RWC) i stężenie chlorofilu, ale stymulował akumulację proliny (Pro). Dodatek EDTA do pożywki zawierającej Cd pozytywnie wpływał na funkcjonowanie cyklu glutationowo-askorbinianowego, zwiększając aktywność peroksydazy askorbinianowej (APX), reduktazy monodehydroaskorbinianowej (MDHAR), reduktazy dehydroaskorbinianowej (DHAR), reduktazy glutationowej (GR), peroksydazy glutationowej (GPX), a także dysmutazy ponadtlenkowej (SOD) i katalazy (CAT). Ponadto, dodanie EDTA do środowiska wzrostu roślin traktowanych Cd zwiększyło aktywność glioksalazy I (Gly I) w roślinach, czego nie stwierdzono w roślinach traktowanych wyłącznie Cd. EDTA ograniczył akumulację Cd zarówno w korzeniach, jak i w częściach nadziemnych, zwiększając jednocześnie poziom niebiałkowych tioli (NPT), w tym fitochelatyn (PC). Dodatkowo, w roślinach traktowanych Cd w obecności EDTA stwierdzono niższy poziom H2O2, O2•− i MG oraz obniżenie peroksydacji lipidów, ale wzrost RWC, a także stężenia chlorofilu i Pro, co wpłynęło na lepszy wzrost roślin. Uzyskane wyniki sugerują, że zastosowanie egzogennego EDTA razem z Cd obniża toksyczność metalu związaną z generowaniem stresu oksydacyjnego, poprzez ograniczenie pobierania Cd, zwiększenie stężenia NPT i pozytywny wpływ na aktywność większości składników systemu antyoksydacyjnego i glioksalazowego.
Źródło:
Acta Agrobotanica; 2019, 72, 2
0065-0951
2300-357X
Pojawia się w:
Acta Agrobotanica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Serodiagnosis of Toxoplasmosis using Lateral Flow Chromatographic Immunoassay among Animals and Humans in Sunsari District of Nepal
Autorzy:
Sah, Ramesh Prasad
Talukder, Md Hasanuzzaman
Rahman, A. K. M. Anisur
Powiązania:
https://bibliotekanauki.pl/articles/1167051.pdf
Data publikacji:
2018
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Animals
Nepal
human
seroprevalence
toxoplasmosis
Opis:
Toxoplasmosis is a cosmopolitan parasitic zoonosis, infecting human and other warm blooded animals worldwide. This disease has economic importance in regard to animal reproduction, and it leads to abortions and neonatal complications in humans. This study was carried out to determine the seroprevalence of Toxoplasma gondii in sheep, cattle, cats and human in Inaruwa and surrounding areas of Sunsari district, Nepal. Altogether 336 blood samples, of which 50 from sheep, 92 from cattle, 44 from cats and 150 from human were collected and tested immediately using lateral flow chromatographic immunoassay (Toxo IgG/IgM Combo Rapid test®). Associated biometric information such as age, sex, pregnancy status, occupation, association with cat was recorded and analyzed to determine the association of risk factors with the disease. Data were analyzed using R 3.2.2 (The R foundation for Statistical Computing, 2015). Seroprevalence of toxoplasmosis was detected 12.00% (95% CI: 4.53- 24.31%) in sheep, 8.70% (95% CI: 3.83- 16.42%) in cattle, 36.36% (95%CI: 22.41- 52.23%) in cats and 12.67% (95% CI: 7.80- 19.07%) in human. In case of human, 31 to 45 years age group were found more susceptible to toxoplasmosis (21.74%, OR: 6.4) in comparison to 21 to 30 years (10.0%) and up to 20 years (4.17%) age groups. Toxoplasmosis was found highly significantly associated with abortion (58.33%, OR= 15.4, P=0.0001) in human in the tested individuals. Regarding occupation, 20.83% butchers were seropositive followed by farmers (15.52%), housewives (10.0%) and diagnostic lab technicians (8.0%). Female and higher age group showed high prevalence of toxoplasmosis in all studied species. Therefore, this assay is a useful method for the serological screening of toxoplasmosis in different animals and humans.
Źródło:
World Scientific News; 2018, 105; 145-156
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of heat treatment on microhardness of electroless Ni-YSZ cermet coating
Autorzy:
Bahiyah Baba, N.
Ghazali, A. S.
Abdul Rahman, A. H.
Sharif, S.
Powiązania:
https://bibliotekanauki.pl/articles/2201036.pdf
Data publikacji:
2022
Wydawca:
Stowarzyszenie Komputerowej Nauki o Materiałach i Inżynierii Powierzchni w Gliwicach
Tematy:
Ni-YSZ
cermet
coating
microhardness
heating temperature
heating time
electroless nickel
powłoka
mikrotwardość
temperatura nagrzewania
czas nagrzewania
bezprądowe powlekanie niklem
Opis:
Purpose: The paper discussed the effect of heat treatment on electroless nickel-yttria-stabilised zirconia (Ni-YSZ) cermet coating. Ni-YSZ cermet coating has potential applications such as cutting tools, thermal barriers, solid oxide fuel anode, and various others. The compatibility of ceramic YSZ and metallic nickel in terms of the mechanical properties such as hardness by varying the heating temperature, time and ceramic particle size is highlighted. Design/methodology/approach: Ni-YSZ cermet coating was deposited onto a highspeed steel substrate using the electroless nickel co-deposition method. The temperature and time were varied in a range of 300-400°C and 1-2 hours, respectively. The microhardness measurements were carried out using a Vickers microhardness tester (Shimadzu) according to ISO 6507-4. The surface characterisation of the cermet coating was carried out using JOEL Scanning Electron Microscope (SEM) coupled with Energy Dispersive X-ray (EDX) JSM 7800F. The crystallographic structure of materials was analysed by X-ray diffraction (XRD) Bruker D8 Advance instrument. Findings: It was found that the microhardness of Ni-YSZ cermet coating with the ratio of 70:30, respectively, is directly proportional to the heating temperature and time. Heating the Ni-YSZ cermet coating at 300°C from room temperature (rtp) to 1 hour shows a 12% microhardness increment, while from 1 to 2 hours gives a 19% increment. Compared to heating at 350°C and 400°C, the increment is more significant at 33% and 49% for rtp to 1 hour and 8% and 16% for 1 to 2 hours, respectively. In addition, the effect of varying YSZ particle size in the Ni-YSZ cermet gave response differently for heating temperature and heating time. Research limitations/implications: The paper is only limited to the discussion of the heat treatment effect on Ni-YSZ cermet coating hardness property. The tribological effect will be in future work. Practical implications: The microhardness data may vary due to the Vickers microhardness force applied and the amount of ceramic particle incorporation and phosphorus content in the nickel matrix. Originality/value: The value of this work is the compatibility of the ceramic YSZ and metallic nickel matrix in terms of mechanical properties, such as hardness, upon heat treatment.
Źródło:
Journal of Achievements in Materials and Manufacturing Engineering; 2022, 113, 1; 5--12
1734-8412
Pojawia się w:
Journal of Achievements in Materials and Manufacturing Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Parametric optimisation of microhardness on heat-treated electroless Ni-YSZ cermet coating
Autorzy:
Bahiyah Baba, N.
Ghazali, A. S.
Abdul Rahman, A. H.
Sharif, S
Powiązania:
https://bibliotekanauki.pl/articles/2172165.pdf
Data publikacji:
2022
Wydawca:
Stowarzyszenie Komputerowej Nauki o Materiałach i Inżynierii Powierzchni w Gliwicach
Tematy:
full factorial
electroless
Ni-YSZ
cermet
coating
microhardness
treating temperature
treating time
silnia
bezprądowy
powłoka
mikrotwardość
temperatura obróbki
czas obróbki
Opis:
Purpose The paper discusses the parametric optimisation of the electroless Ni-YSZ cermet coating microhardness upon heat treatment. Heat treatment is a process to increase the mechanical properties of the electroless nickel coating and it can be enhanced by manipulating its parameters. Parametric optimisation is conducted by the design of experiment full factorial 3x3 with 27 runs. Treating temperature, treating time and ceramic particle size parameters at 3-level are evaluated using statistical tool ANOVA in Minitab20. Design/methodology/approach Ni-YSZ cermet coating is deposited onto a high-speed steel substrate using the electroless nickel co-deposition method. The temperature and time were varied in a range of 300-400oC and 0-2 hours respectively. The microhardness measurements were carried out using a Vickers microhardness tester (Shimadzu) according to ISO 6507-4. The surface characterisation was analysed using Cambridge Stereoscan 90 Scanning Electron Microscope (SEM) coupled with Energy Dispersive X-ray Analysis (EDXA). Findings The optimum condition in obtaining high microhardness on Ni-YSZ cermet coating is evaluated by statistical tool ANOVA in Minitab20 software. It is found that the most significant parameter for high microhardness is at the treating temperature of 400oC followed by treating time at 2 hours using nano-sized YSZ particles. The ceramic particle size is found not a significant parameter in obtaining a high microhardness, however it has effect on interaction between treating temperature and treating time. Research limitations/implications The paper only limits to the optimisation condition of microhardness on Ni-YSZ cermet coating hardness property by varying heat treatment parameters. Practical implications The optimisation condition obtained might only applicable to the electroless Ni-YSZ cermet coating with similar electroless nickel solution and treatments. Originality/value The value of this work is the heat treatment parametric optimisation to obtain high microhardness on electroless Ni-YSZ cermet coating by using the design of experiment 3-level full factorial.
Źródło:
Journal of Achievements in Materials and Manufacturing Engineering; 2022, 112, 1; 33--41
1734-8412
Pojawia się w:
Journal of Achievements in Materials and Manufacturing Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of particle size on surface roughness and morphology of heat-treated electroless Ni-YSZ coating
Autorzy:
Bahiyah Baba, N.
Ghazali, A. S.
Azinee, S. N.
Abdul Rahman, A. H.
Sharif, S.
Powiązania:
https://bibliotekanauki.pl/articles/2201055.pdf
Data publikacji:
2022
Wydawca:
Stowarzyszenie Komputerowej Nauki o Materiałach i Inżynierii Powierzchni w Gliwicach
Tematy:
particle size
electroless coatings
Ni-YSZ
heat treatment
surface roughness
surface morphology
wielkość cząstek
powłoka
powlekanie bezprądowe
obróbka cieplna
chropowatość powierzchni
morfologia powierzchni
Opis:
Purpose The paper discusses the surface characterisation of electroless nickel-yttria-stabilised zirconia (Ni-YSZ) coating with varying YSZ particle sizes and undergoes heat treatment at a temperature between 300-400°C for 1-2 hours for wear resistance purposes. This finding will be helpful to the application of Ni-YSZ as an alternative coating for cutting tools. Design/methodology/approach The surface characterisation was analysed using JOEL Scanning Electron Microscope (SEM) coupled with Energy Dispersive X-ray (EDX) JSM 7800F. The crystallographic structure of materials was analysed by X-ray diffraction (XRD) Bruker D8 Advance instrument. The Ni-YSZ coating was deposited using electroless nickel co-deposition of 8YSZ ceramic particles with a nano, mixed and microparticle sizes onto a high-speed steel (HSS) substrate. The coatings were heat treated at temperature 300-400°C and time 1-2 hours. The surface roughness was measured using Mitutoyo surface roughness tester SJ-301. Findings The electroless Ni-YSZ coating deposited has an average thickness of 30 µm. It is found that the coating morphology electroless coating without YSZ particle incorporation (EN) and Ni-YSZ nano (N) is smoother compared to the Ni-YSZ mixed (NM) and Ni-YSZ micro (M). The EDS composition analysis shows the YSZ content in the electroless Ni-YSZ coating for N samples is the lowest, whereas NM samples are the highest. This resulted in the surface roughness behaviour where the mixed-size YSZ particle gives the highest roughness at all temperatures. The XRD analysis shows that heating temperatures above 300°C caused the precipitation of Ni3P crystalline. Research limitations/implications Previous studies in the surface characterisation of electroless nickel composite are scarce; thus, the study has limitations in finding supporting data. Originality/value The surface characterisation especially related to the surface roughness of the electroless nickel, either the Ni-P or composites or alloys are rarely reported. Thus, this study enlightened the effect of particle size on surface roughness and morphology of heat-treated coatings.
Źródło:
Journal of Achievements in Materials and Manufacturing Engineering; 2022, 114, 1; 5--14
1734-8412
Pojawia się w:
Journal of Achievements in Materials and Manufacturing Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Friction and adhesion energy of polymer–polymer sliding combinations
Tarcie i energia adhezji podczas ślizgania w połączeniach polimer–polimer
Autorzy:
Marzouk, W. W.
Abdel-Rahman, M. A.
Powiązania:
https://bibliotekanauki.pl/articles/188045.pdf
Data publikacji:
2012
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
friction coefficient
reversible adhesion energy
hardness ratio
polymer–polymer pairs
współczynnik tarcia
energia adhezji
wskaźnik twardości
połączenie polimer–polimer
Opis:
The friction coefficient, reversible adhesion energy and hardness ratio of polymer-polymer combinations such as PC, PS, PTFE, PA6, LDPE and PP are examined using a pin-on-ring type tribometer. Polycarbonate has been used as a ring material. The applied loads are 10, 20, 30, 40, and 50 N. The coefficient of friction as a function of sliding time, applied load, and hardness ratio has been observed. Additionally, the relationship between the coefficient of friction and reversible adhesion energy calculated from the surface components is calculated. The results show that the coefficient of friction is highly dependent on the reversible energy. The coefficient of friction increases as the reversible adhesion energy increases. At a hardness ratio equal to unity, the coefficient of friction exhibits high values. At higher values of the hardness ratio, HC/Hp = 2.4, however, the coefficient of friction possesses low values. In addition, the coefficient of friction is highly dependent on the load applied. It decreases with the increase in the load.
W pracy przedstawiono wyniki badań współczynnika tarcia, odwracalnej energii adhezji i stosunku twardości połączeń polimer-polimer, takich jak PC, PS, PTFE, PA6, LDPE i PP, które określano przy użyciu testera typu trzpień–pierścień. Na materiał pierścienia wykorzystano poliwęglan. Zastosowano obciążenia 10, 20, 30, 40 i 50N. Obserwowano zmianę współczynnika tarcia w funkcji czasu ślizgania, przyłożonego obciążenia i wskaźnika twardości. Ponadto obliczano zależność pomiędzy współczynnikiem tarcia i odwracalną energią adhezji. Wyniki pokazują, że współczynnik tarcia jest bardzo zależny od energii adhezji. Współczynnik tarcia wzrasta wraz ze wzrostem energii adhezji. Przy jednakowej twardości materiałów współczynnik tarcia przyjmuje wysokie wartości. Przy wyższych wartościach wskaźnika twardości, HC/Hp = 2.4, współczynnik tarcia ma małą wartość. Dodatkowo, współczynnik tarcia bardzo zależy od przyłożonego obciążenia – jego wartość maleje wraz ze wzrostem obciążenia.
Źródło:
Tribologia; 2012, 5; 97-106
0208-7774
Pojawia się w:
Tribologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The youngest ctenocystoids from the Upper Ordovician of the United Kingdom and the evolution of the bilateral body plan in echinoderms
Autorzy:
Rahman, I.A.
Stewart, S.E.
Zamora, S.
Powiązania:
https://bibliotekanauki.pl/articles/945494.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Echinodermata
Ctenocystoidea
evolution
bilateral symmetry
Ordovician
ctenocystoid
Upper Ordovician
United Kingdom
bilateral body
echinoderm
Opis:
During the early Palaeozoic, echinoderm body plans were much more diverse than they are today, displaying four distinct types of symmetry. This included the bilateral ctenocystoids, which were long thought to be restricted to the Cambrian. Here, we describe a new species of ctenocystoid from the Upper Ordovician of Scotland (Conollia sporranoides sp. nov.). This allows us to revise the genus Conollia, which was previously based on a single poorly-known species from the Upper Ordovician of Wales (Conollia staffordi). Both these species are characterized by a unique morphology consisting of an elongate-ovoid body covered in spines, which clearly distinguishes them from their better-known Cambrian relatives; they are interpreted as infaunal or semi-infaunal burrowers from deep-water environments. This indicates that the ctenocystoid body plan was not fixed early in the evolution of the group, and they most likely modified their structure as an adaptation to a new mode of life in the Ordovician.
Źródło:
Acta Palaeontologica Polonica; 2015, 60, 1; 39-48
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Propagation of threatened climber species Entada rheedii Spreng. – a medicinal plant with extremely thick and hard seed coat
Autorzy:
Hossain, M.A.
Dey, J.
Rahman, M.A.
Powiązania:
https://bibliotekanauki.pl/articles/2078264.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Instytut Dendrologii PAN
Tematy:
Entada rheedii
germination potential
growth performance
pre-sowing treatments
rooting abil-
ity
rooted cuttings
Opis:
The study explored propagation techniques of Entada rheedii Spreng., a threatened medicinal climber species with extremely hard seed coat. Propagation trials included both pre-sowing treatments of seeds for germination and clonal propagation by stem cutting. Pre-sowing treatments included (a) soaking of both cut (notched) and uncut (intact) seeds in water for 0 h, 24 h, 48 h, and 72 h and (b) immersion of intact seeds in 5% acetone solution for 5 min, 10 min, and 20 min before sowing in germination media in polybags. On the other hand, stem cutting involved treating the summer or autumn cuttings with 0%, 0.4%, and 0.8% IBA solution before rooting in non-mist propagator. Notched seeds soaked in water for 48 h showed the fastest seed germination with the highest germination percentages (73.3) and better seedling growth in terms of plant height, collar diameter, leaf number and total dry mass followed by notched seeds soaked in water for 72 h. The slowest germination and the lowest germination percentage (3.3), as well as the poorest growth performance was for intact seeds without any treatment. The highest rooting percent- age with maximum number of roots (36.6) was obtained from the summer cuttings treated with 0.4% IBA solution followed by autumn cuttings with 0.8% IBA and the lowest (43.3% and 8.3 roots) was for summer cuttings in control. The factors also dictated the survival and growth performance of rooted cuttings in the nursery conditions. The outcomes of these trials i.e., notched seeds soaking in water for 48 h will help to enhance the propagation of this valuable medicinal plant species.
Źródło:
Dendrobiology; 2021, 85; 92-104
1641-1307
Pojawia się w:
Dendrobiology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Response of non-linear shock absorbers-boundary value problem analysis
Autorzy:
Rahman, M. A.
Ahmed, U.
Uddin, M. S.
Powiązania:
https://bibliotekanauki.pl/articles/265424.pdf
Data publikacji:
2013
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
amortyzator
tłumik drgań
stabilność
wartość graniczna
shock absorber
untuned vibration damper
frequency ratios
non-linear springs
non-linear dampers
stability
boundary value problem
multisegment method of integration
Opis:
A nonlinear boundary value problem of two degrees-of-freedom (DOF) untuned vibration damper systems using nonlinear springs and dampers has been numerically studied. As far as untuned damper is concerned, sixteen different combinations of linear and nonlinear springs and dampers have been comprehensively analyzed taking into account transient terms. For different cases, a comparative study is made for response versus time for different spring and damper types at three important frequency ratios: one at r = 1, one at r > 1 and one at r <1. The response of the system is changed because of the spring and damper nonlinearities; the change is different for different cases. Accordingly, an initially stable absorber may become unstable with time and vice versa. The analysis also shows that higher nonlinearity terms make the system more unstable. Numerical simulation includes transient vibrations. Although problems are much more complicated compared to those for a tuned absorber, a comparison of the results generated by the present numerical scheme with the exact one shows quite a reasonable agreement.
Źródło:
International Journal of Applied Mechanics and Engineering; 2013, 18, 3; 793-814
1734-4492
2353-9003
Pojawia się w:
International Journal of Applied Mechanics and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Distributed generation’s integration planning involving growth load models by means of genetic algorithm
Autorzy:
Rahman, Y. A.
Manjang, S.
Yusran, A.
Ilham, A.
Powiązania:
https://bibliotekanauki.pl/articles/141167.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
distributed generation
genetic algorithm
load models
power loss
load growth
Opis:
The growth in the system load accompanied by an increase of power loss in the distribution system. Distributed generation (DG) is an important identity in the electric power sector that substantially overcomes power loss and voltage drop problems when it is coordinated with a location and size properly. In this study, the DG integration into the network is optimally distributed by considering the load conditions in different load models used to surmount the impact of load growth. There are five load models tested namely constant, residential, industrial, commercial and mixed loads. The growth of the electrical load is modeled for the base year up to the fifth year as a short-term plan. Minimization of system power loss is taken as the main objective function considering voltage limits. Determination of the location and size of DG is optimally done by using the breeder genetic algorithm (BGA). The proposed studies were applied to the IEEE 30 radial distribution system with single and multiple placement DG scenarios. The results indicated that installing an optimal location and size DG could have a strong potential to reduce power loss and to secure future energy demand of load models. Also, commercial load requires the largest DG active injection power to maintain the voltage value within tolerable limits up to five years.
Źródło:
Archives of Electrical Engineering; 2018, 67, 3; 667--682
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Measurement of radioactive impact of the gas well accident on environment of Sylhet division in Bangladesh
Autorzy:
Chakraborty, S. R.
Saha, K. K.
Rahman, A. K. M. R.
Kamal, M.
Chowdhury, M. I.
Alam, Md. K.
Powiązania:
https://bibliotekanauki.pl/articles/411611.pdf
Data publikacji:
2013
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Natural gas well accident
Environmental radioactivity
Public exposure etc
Opis:
The main goal of this study is to carry out the public exposure contribution from radioactive materials occurring due to the accident of natural gas exploration well of Sylhet division in Bangladesh. This study has been performed by using a gamma spectrometry of Genie 2000 software embedded PC-based High Purity Germanium (HPGe) detector system. The measured activity concentrations of naturally occurring radionuclides 232Th, 226Ra, and 40K have been in the public safety limit on the environment of the study areas. The specific activity of detected anthropogenic radionuclide 137Cs has been found to be very little with a mean value of 1.65 ± 0.61 and 1.13 ± 0.57 Bq•kg–1 in the Magurchhera and Haripur gas field area respectively.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2013, 9, 1; 48-60
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Assessment of Radiological Dose around a 3-MW TRIGA Mark-II Research Reactor
Autorzy:
Rahman, A. F. M. M.
Shamsuzzaman, M.
Rahman, M. S.
Uddin, K.
Yeasmin, S.
Nazmul, Haque H. M.
Akramuzzaman, M. M.
Chakraborty, S. R
Powiązania:
https://bibliotekanauki.pl/articles/412377.pdf
Data publikacji:
2013
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
source term
release rate
TRIGA Mark-II reactor
dispersion
ingestion and deposition of radionuclide
Gaussian plume model
dose calculations
Opis:
A hypothetical accidental case of a 3-MW TRIGA Mark-II research reactor has been assumed to assess the radiological consequences due to the deposition of 137Cs and 90Sr on ground, vegetation, milk and meat. The air concentrations in sixteen cardinal directions have been estimated where the maximum concentration has been found to be at 110 m distance from the core of the reactor for all the directions. Calculated maximum doses of 137Cs, 90Sr and both 137Cs and 90Sr have been found to be within the ranges of 0.005-0.014 μSv hr–1, 0.013-0.036 μSv hr–1 and 0.018-0.05 μSv hr–1, respectively for all the directions, which are below the measured background dose limit 0.25 μSv hr–1 and also within the IAEA acceptable dose rate limit of 0.5 μSv hr–1. The calculated low doses due to the aforementioned radionuclides can be considered negligible with regard to the radiation hazards. The relationship between total effective dose rate for various pathways (i.e. immersion, inhalation, ground deposition, and ingestion of contaminated vegetation, milk, meat) and air concentration in all the directions has been established. Obtained relation reveals that the total effective dose rate is directly proportional to the air concentration, and the overall proportionality constants for 137Cs and 90Sr radionuclides have been obtained as 0.57 and 0.28, respectively. This study might provide information on the radiological safety required for the radiation protection purposes of the people living in the vicinity of the reactor site.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2013, 10, 2; 183-200
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optimization of fresh palm oil mill effluent biodegradation with Aspergillus niger and Trichoderma virens
Autorzy:
Jalaludin, N.
Rahman, R. A.
Razali, F.
Barghash, H. F. A.
Sukri, S. S. M.
Powiązania:
https://bibliotekanauki.pl/articles/204704.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Aspergillus niger
optimization
POME
palm oil mill effluent
Trichoderma virens
Opis:
In this work, response surface optimization strategy was employed to enhance the biodegradation process of fresh palm oil mill effluent (POME) by Aspergillus niger and Trichoderma virens. A central composite design (CCD) combined with response surface methodology (RSM) were employed to study the effects of three independent variables: inoculum size (%), agitation rate (rpm) and temperature (°C) on the biodegradation processes and production of biosolids enriched with fungal biomass protein. The results achieved using A. niger were compared to those obtained using T. virens. The optimal conditions for the biodegradation processes in terms of total suspended solids (TSS), turbidity, chemical oxygen demand (COD), specific resistance to filtration (SRF) and production of biosolids enriched with fungal biomass protein in fresh POME treated with A. niger and T. virens have been predicted by multiple response optimization and verified experimentally at 19% (v/v) inoculum size, 100 rpm, 30.2°C and 5% (v/v) inoculum size, 100 rpm, 33.3°C respectively. As disclosed by ANOVA and response surface plots, the effects of inoculum size and agitation rate on fresh POME treatment process by both fungal strains were significant.
Źródło:
Archives of Environmental Protection; 2016, 42, 1; 63-73
2083-4772
2083-4810
Pojawia się w:
Archives of Environmental Protection
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of 2014 massive flood on well water qualities: A case study on Kelantan River basin, Malaysia
Wpływ ekstremalnej powodzi z 2014 roku na jakość wód w studniach: Przykład basenu rzeki Kelantan w Malezji
Autorzy:
Rahman, H. A. Ab.
Ibrahim, N. A.
Abdul Hamid, A. A.
Abdul Hamid, T. H. T.
Powiązania:
https://bibliotekanauki.pl/articles/292275.pdf
Data publikacji:
2018
Wydawca:
Instytut Technologiczno-Przyrodniczy
Tematy:
drinking well
flood inundation
Kelantan River basin
total coliform
water quality
bakterie typu coli
basen rzeki Kelantan
jakość wody
woda pitna
zalanie wodami powodziowymi
Opis:
The effect of physical and biological qualities of wells after submergence was assessed following December 2014 flood in Kelantan. Studies were carried out on a total of 65 wells from 13 stations around Kelantan River basin in which the wells’ water were sampled for pH, total dissolved solid (TDS), turbidity and microbial contamination. About 95% of the well showed to be contaminated, 7 out of 65 samples (11.1%) showed TDS values >400 μS·cm–1; and 19 samples (29.2%) recorded turbidity beyond 7.0 NTU. Statistical non-parametric tests carried out on independent groups showed that the status of well contamination was neither determined by both degree of submergence nor by the geographical location. Also the physico-chemical parameters are independent of flood inundation. However, TDS and turbidity values changed based on geographical location, at p < 0.05. Well from estuary recorded higher TDS (241.2 μS·cm–1 ±159.5 SD) and turbidity (8.04 NTU ± 6.53 SD) compared to those from inner basin (TDS at 156.3 μS·cm–1± 88.9 SD; turbidity at 2.90 NTU ± 2.46 SD), respectively. The flood water had played significant role in the transmission of existing contaminant, and most of the wells were unsafe for drinking. We concluded that the degree of flood submergence does not necessarily determine the severity of the well contamination in Kelantan, but the existing contamination may exacerbate further the potential risk during post flood period.
Oceniano fizyczne i biologiczne właściwości wód w studniach zalanych w wyniku powodzi w grudniu 2014 r. w basenie rzeki Kelantan. Badania prowadzono łącznie w 65 studniach z 13 stanowisk w basenie rzeki. Analizowano pH, zawartość substancji rozpuszczonych (TDS), mętność i zanieczyszczenie mikrobiologiczne. Zanieczyszczenia wykryto w ok. 95% studni, w 7 z 65 stwierdzono wartości TDS > 400 μS·cm–1, a 19 próbek (29,2%) miało mętność ponad 7,0 NTU. Statystyczne testy dla zmiennych niezależnych wykazały, że poziom zanieczyszczeń nie zależał ani od stopnia zalania, ani od lokalizacji. Fizyczne i chemiczne parametry wody także nie były zależne od zalewu powodziowego, TDS i mętność zmieniały się wraz z położeniem geograficznym z istotnością p < 0,05. W wodzie ze studni z estuarium rzeki wartości TDS i mętność (odpowiednio 241,2 μS·cm–1 ±159,5 SD i 8,04 NTU ±6,53 SD) były większe niż w wodzie ze studni w głębi basenu (TDS 156,3 μS·cm–1 ±88,9 SD, mętność 2,90 NTU ±2,46 SD). Wody powodziowe odgrywały istotną rolę w przenoszeniu zanieczyszczeń. Większość wód studziennych nie nadawała się do picia. Stwierdzono ostatecznie, że stopień zalania studni niekoniecznie determinuje stopień zanieczyszczenia studni, ale występujące zanieczyszczenia mogą zwiększać potencjalne ryzyko po ustąpieniu powodzi.
Źródło:
Journal of Water and Land Development; 2018, 38; 127-136
1429-7426
2083-4535
Pojawia się w:
Journal of Water and Land Development
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Towards the propagation of a critically endangered tree species Anisoptera scaphula
Autorzy:
Hossain, M.A.
Ferdous, J.
Rahman, M.A.
Azad, M.A.K.
Shukor, N.A.A.
Powiązania:
https://bibliotekanauki.pl/articles/41522.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Instytut Dendrologii PAN
Tematy:
propagation
endangered species
tree
Anisoptera scaphula
Dipterocarpaceae
seed
sowing position
germination percentage
rooting ability
Opis:
Anisoptera scaphula (Roxb.) Kurz, the tallest tree species in Bangladesh, is critically endangered worldwide due to its poor natural regeneration. This study describes the appropriate regeneration technique for A. scaphula through seed germination and clonal propagation by stem cutting. The fastest and highest germination percentage (65) was observed in dewinged seeds sown inverted orientation with half buried position (T10) followed by dewinged seeds (62.5%) sown horizontally in full buried (T7) and delayed germination with lowest percentage (15) was in control (T0). Optimum initial growth was also shown when seedlings were developed from the seeds under T7. Both winged and dewinged seeds sown vertically in full buried or half buried position produced curved seedlings. However, dewinged seeds sown in horizontal or inverted (winged side down) position produced otherwise i.e., straight seedlings. The highest rooting percentages (63%) and maximum number of root (4.8) per cutting were obtained when one node cuttings treated with 0.8% IBA solution followed by 0.4% IBA in turn affecting for better survival and growth of rooted cuttings in the nursery conditions.
Źródło:
Dendrobiology; 2014, 71
1641-1307
Pojawia się w:
Dendrobiology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Bond strength of concrete-filled hollow section with modified fibrous foamed concrete
Autorzy:
Khairuddin, S. A. A.
Rahman, N. A.
Jamaluddin, N.
Jaini, Z. M.
Elamin, A.
Rum, R. H. M.
Powiązania:
https://bibliotekanauki.pl/articles/230151.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
siła wiązania
pusta sekcja wypełniona betonem
CFHS
beton modyfikowany
beton włóknisty
beton spieniony
popiół z łusek ryżowych
RHA
wytrzymałość
metoda push-out
bond strength
concrete filled hollow section
modified fibrous foamed concrete
rice husk ash
strength
push-out method
Opis:
The concrete-filled section of columns has been widely in construction used due to its structural elements. As a result, the usage of composite columns has recently increased all over the world. However, using foamed concrete alone does not result in much improvements in strength. Therefore, this paper examines the use of foamed concrete containing fibre to improve the strength of composite columns. Specifically, this study aims to determine the bond strength of concrete-filled hollow section (CFHS) with modified fibrous foamed concrete. Two types of fibre are used in this work, namely, steel fibre and polypropylene fibre, with rice husk ash (RHA) as a sand replacement to improve the compressive strength of foamed concrete. The CFHS with modified fibrous foamed concrete is tested by using the push-out method, and the results show that CFHS with steel fibre has a highest bond strength.
Źródło:
Archives of Civil Engineering; 2020, 66, 3; 97-108
1230-2945
Pojawia się w:
Archives of Civil Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Schwarz-Pick theorem and its applications
Autorzy:
Qazi, M. A.
Rahman, Q. I.
Powiązania:
https://bibliotekanauki.pl/articles/747151.pdf
Data publikacji:
2011
Wydawca:
Uniwersytet Marii Curie-Skłodowskiej. Wydawnictwo Uniwersytetu Marii Curie-Skłodowskiej
Tematy:
Bernstein’s inequality
functions of exponential type in a half-plane
rational functions
Schwarz-Pick theorem
Opis:
Various derivative estimates for functions of exponential type in a half-plane are proved in this paper. The reader will also find a related result about functions analytic in a quadrant. In addition, the paper contains a result about functions analytic in a strip. Our main tool in this study is the Schwarz-Pick theorem from the geometric theory of functions. We also use the Phragmen-Lindelof principle, which is of course standard in such situations.
Źródło:
Annales Universitatis Mariae Curie-Skłodowska, sectio A – Mathematica; 2011, 65, 2
0365-1029
2083-7402
Pojawia się w:
Annales Universitatis Mariae Curie-Skłodowska, sectio A – Mathematica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Thin and Rectangular Die Bond Pick-Up Mechanism to Reduce Cracking During the Integrated Circuit Assembly Process
Autorzy:
Rahman, Ahmad R. A.
Nayan, Nazrul Anuar
Powiązania:
https://bibliotekanauki.pl/articles/102963.pdf
Data publikacji:
2020
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
die attachment
miniaturization
integrated circuit
packaging process
mocowanie matrycy
miniaturyzacja
układ scalony
proces pakowania
Opis:
The demand for small, thin, and lightweight electronic devices is increasing. More advanced design and assembly processes of electronic packaging technology have developed to fulfill this need. The critical processes in semiconductor packaging involved in meeting the ever increasing demands of technology include wafer back grinding, dicing, and die attachment. With low die thickness, the risk of die failure, which can cause functional damage, is high. In the die attachment process, the pin ejector causes an impact during the pick and place process. Those effects can result in a micro indentation or micro crack under the die and would be the weak point throughout the entire process. This study designed and evaluated an ejector system for the die attachment process. The proposed method uses a static pole heated inside the cavity for the platform to die before being ejected. Vacuum stabilizes the die suction. Moreover, heat softens the sawing tape and weakens the die adhesion. For die selection during the die attachment process, the results show that the critical die crack problem for a thin and rectangular die is solved using the proposed method. In summary, the packaging of semiconductors has advanced to accommodate the pick-up technology solution in relation to the challenging material needed for the current miniaturization market trend and demand.
Źródło:
Advances in Science and Technology. Research Journal; 2020, 14, 3; 57-64
2299-8624
Pojawia się w:
Advances in Science and Technology. Research Journal
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Stack Parameters Effect on the Performance of Anharmonic Resonator Thermoacoustic Heat Engine
Wpływ parametrów stosu na osiągi anaharmonicznego rezonatora termo akustycznej maszyny cieplnej
Autorzy:
Nouh, M. A
Arafa, N
Abdel-Rahman, E
Powiązania:
https://bibliotekanauki.pl/articles/140035.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
thermoacoustic
stack
anharmonic
resonator
engine
optimization
termoakustyka
stos
silnik
rezonator
Opis:
A thermoacoustic heat engine (TAHE) converts heat into acoustic power with no moving parts. It exhibits several advantages over traditional engines, such as simple design, stable functionality, and environment-friendly working gas. In order to further improve the performance of TAHE, stack parameters need to be optimized. Stack’s position, length and plate spacing are the three main parameters that have been investigated in this study. Stack’s position dictates both the efficiency and the maximum produced acoustic power of the heat engine. Positioning the stack closer to the pressure anti-node might ensure high efficiency on the expense of the maximum produced acoustic power. It is noticed that the TAHE efficiency can further be improved by spacing the plates of the stack at a value of 2.4 of the thermal penetration depth, ςk . Changes in the stack length will not affect the efficiency much as long as the temperature gradient across the stack, as a ratio of the critical temperature gradient Γ, is more than 1. Upon interpreting the effect of these variations, attempts are made towards reaching the engine’s most powerful operating point.
Termoakustyczna maszyna cieplna (TAHE) przekształca ciepło w energie akustyczna bez użycia części ruchomych. W porównaniu z maszynami tradycyjnymi ma ona szereg zalet, takich jak prosta konstrukcja, stabilność działania oraz wykorzystanie gazów przyjaznych dla środowiska. W celu dalszej poprawy osiągów maszyny TAHE należy zoptymalizować parametry stosu (zespołu wąskich kanałów miedzy płytami wymiennika ciepła). Trzema głównymi parametrami analizowanymi w przedstawionej pracy są pozycja stosu, długości, odstęp między płytami. Pozycja stosu decyduje zarówno o sprawności jak maksymalnej mocy akustycznej wytwarzanej przez maszynę cieplną. Umieszczenie stosu bliżej strzałki fali stojącej może zapewnić większą sprawność kosztem maksymalnej wytwarzanej mocy akustycznej. Stwierdzono, że dalsza poprawa sprawności maszyny TAHE może być osiągnięta gdy zastosuje się odstęp płyt stosu równy 2,4 cieplnej głębokości wnikania, k . Zmiany długości stosu nie maja wielkiego wpływu na sprawność tak długo, jak stosunek krytycznego gradientu cieplnego jest większy od 1. Na podstawie interpretacji efektów tych zmian podjęto wysiłki dla uzyskania najlepszych osiągów maszyny.
Źródło:
Archive of Mechanical Engineering; 2014, LXI, 1; 115-127
0004-0738
Pojawia się w:
Archive of Mechanical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Microbial degradation of lignocellulosic biomass: discovery of novel natural lignocellulolytic bacteria
Autorzy:
Ahmed, S.
Rahman, S.
Hasan, M.
Paul, N.
Sajib, A.A.
Powiązania:
https://bibliotekanauki.pl/articles/81125.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
lignocellulose
microbial degradation
biofuel
cellulose
lignin
hemicellulose
lignocellulolytic bacteria
Chryseobacterium gleum
Źródło:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology; 2018, 99, 2
0860-7796
Pojawia się w:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Electroluminescence Enhancement of Polymer Light Emitting Diodes Through Surface Plasmons by Ag Nanoplates
Autorzy:
Aziz, T.
Salleh, M.
Bakar, N.
Umar, A.
Rahman, M.
Powiązania:
https://bibliotekanauki.pl/articles/1186484.pdf
Data publikacji:
2016-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
73.20.Mf
Opis:
This paper reports a study on the surface plasmon effect of Ag nanoplates on electroluminescent property of polymer light emitting diodes. The diode is a single layer light emitting device made of poly [9,9-di-(2-ethylhexyl)-fluorenyl-2,7-diyl] (PEHF). 5 wt.% of Ag nanoplates were incorporated into the PEHF layer. The results showed that the electroluminescence intensity of the diodes is increased by 51.85%, compared with the device without the Ag nanoplates. The enhancement is due to the coupling process between the Ag surface plasmon with the emission light from the PEHF. The occurrence of the coupling process was proved firstly based on the fact that the exciton lifetime of the PEHF:Ag layer is shorter than that without Ag, as measured by time-resolved photoluminescence spectroscopy. Secondly, the PEHF photoluminescence peak at 425 nm is overlaping with the surface plasmon absorption peak of Ag nanoplates.
Źródło:
Acta Physica Polonica A; 2016, 129, 4; 711-713
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Developmental expression and hormonal regulation of male-specific yellow protein mRNA in adults of the desert locust, Schistocerca gregaria
Autorzy:
Begum, M.
Rahman, M.M.
Huybrechts, R.
De Loof, A.
Powiązania:
https://bibliotekanauki.pl/articles/55232.pdf
Data publikacji:
2008
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
Schistocerca gregaria
yellow protein
phase transition
juvenile hormone
polymorphism
body colour
adult
yellow colouration
insulin
male
sex determination
insect
hormonal regulation
sex hormone
desert locust
Opis:
Adult males of Schistocerca gregaria turn yellow when they become sexually mature. This is due to the deposition in the cuticle of a male-specific Yellow Protein (YP), of which the amino acid sequence is known. Yellowing only happens in crowd-reared (gregarious) males, and results from the deposition of a specific ‘Yellow Protein’. If individual males (solitarious) are isolated after the adult emergence, they become sexually mature but they do not turn yellow. On the basis of a partial YP-mRNA sequence, we established a reverse transcriptase polymerase chain reaction (RT-PCR) assay to study the developmental expression of YP in crowd-reared males, isolated-reared males and females. In crowd-reared adult males the transcription of YP gene started from day 5 on, and reached a maximum at day 12. The effects of juvenile hormone (JH), insulin (bovine), corazonin, ecdysone and 20 0H-ecdysone (20E) on the regulation of YP-mRNA synthesis were also investigated. JH made the cuticle turn yellow and, as shown by RT-PCR, YP-mRNA was induced. The effect of 100 μg JHIII was stronger than that of 10 μg. Insulin was only effective in inducing YP-mRNA synthesis at high dose (19 μg) and after more days (18 d). Corazonin and 20E made the cuticle turn black, but no YP-mRNA synthesis was observed. Ecdysone (10 and 100 μg) showed no effect on body coloration and YP-mRNA. Thus, JH was found to be the most potent inducer among the hormones tested.
Źródło:
Pestycydy; 2008, 1-2; 35-41
0208-8703
Pojawia się w:
Pestycydy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Contributing variables for sustainable livelihood status of the char women in Bangladesh
Czynniki determinujące zrównoważony poziom życia kobiet z terenów zalewowych Bangladeszu
Autorzy:
Al-Amin, S.
Rahman, M.M.
Miah, M.A.M.
Powiązania:
https://bibliotekanauki.pl/articles/43936.pdf
Data publikacji:
2012
Wydawca:
Uniwersytet Przyrodniczy w Poznaniu. Wydawnictwo Uczelniane
Opis:
The main purpose of the study was to determine the contribution of variables to the sustainable livelihood status of char women. The sustainable livelihood status of a char woman was measured by computing a “sustainable livelihood status score” which is considering six major aspects of her livelihoods: food security, ability to provide family education, health and sanitation, shelter and family assets, clothing condition and social upliftment. Data were collected from 200 randomly selected char women by using interview schedule in two Upazilla of Jamalpur district in Bangladesh during November 2006 to March 2007. More than two-fifths (67.5 per cent) of the char women were found under “medium sustainable livelihood status” compared to more than one-fifth (20.5 per cent) of them belongs to ‘low sustainable livelihood status’ and only 12 per cent to “high sustainable livelihood status”. Pearson correlation test depicted that out of 16 variables, 13 had significant positive relationships with the sustainable livelihood status. Results of stepwise multiple regression analysis revealed that five variables namely, annual income, agricultural knowledge, income generating activities, family education and organizational participation contributed significantly which combindly explained 76.3 per cent of total variation to the sustainable livelihood status. Path analysis indicated that these variables had both direct and indirect effects to the sustainable livelihood status. Women who had more annual income, better agricultural knowledge, participation in income generating activities, more family education and more organizational participation were found to better sustainable livelihood status in char area. Government or concern other authorities need to give attention to these variables for any sustainable livelihood upliftment programme.
Głównym celem badania było określenie udziału zmiennych wpływających na zrównoważony poziom życia kobiet z terenów zalewowych. Pomiaru zrównoważonego poziomu życia dokonano w oparciu o wskaźnik, który uwzględniał sześć zmiennych: bezpieczeństwo żywnościowe, zdolność do zapewnienia edukacji rodzinie, zdrowie i warunki sanitarne, schronienie i majątek rodziny, stan odzieży oraz poprawę sytuacji społecznej. Dane do badania pochodzą z wywiadu przeprowadzonego w okresie od listopada 2006 roku do marca 2007 roku wśród 200 losowo wybranych kobiet z terenów zalewowych z dwóch dystryktów Bangladeszu: Upazila i Jamalpur. Ponad połowa (67,5%) kobiet z terenów zalewowych określiła swój poziom życia jako średni, podczas gdy według 1/5 (20,5%) poziom ich życia był niski. Tylko 12% określiło swój poziom życia jako wysoki. Współczynnik korelacji Pearsona wykazał, że spośród 16 zmiennych 13 miało dodatni, istotny statystycznie, wpływ na badane zjawisko. Wyniki analizy regresji krokowej wykazały, że pięć zmiennych: dochód roczny, wiedza rolnicza, działalność generująca dochód, wykształcenie rodziny oraz uczestnictwo w organizacjach w 76,3% wyjaśniło zmienność w ocenie poziomu życia. Analiza ścieżkowa wykazała, że zmienne te wywierają zarówno bezpośredni, jak i pośredni wpływ na badane zjawisko. Grupa kobiet o większych rocznych dochodach, lepszej wiedzy rolniczej i wykształceniu, uczestniczących w działalności generującej dochód oraz częściej uczestniczących w organizacjach, charakteryzowała się wyższym poziomem życia. Konieczne jest, aby rząd i inne instytucje, odpowiedzialne za prowadzoną politykę, w programach mających na celu podniesienie poziomu życia zwracały uwagę na te aspekty, które, zgodnie z wynikami przeprowadzonego badania, przyczyniają się do poprawy poziomu życia kobiet na terenach zalewowych w Bangladeszu.
Źródło:
Journal of Agribusiness and Rural Development; 2012, 23, 1
1899-5241
Pojawia się w:
Journal of Agribusiness and Rural Development
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Study of the Variations in the Vertical and Horizontal Distribution of Heavy Sand Minerals in the Hilla River Sediments
Autorzy:
Hameed, Iman A.
Rahman, Haleema Abdul Jabbar Abdul
Anmar, Alsaadi
Powiązania:
https://bibliotekanauki.pl/articles/27323812.pdf
Data publikacji:
2023
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
sediment
heavy minerals
specific gravity
Opis:
This study was conducted to investigate the effect of the Hilla River sediments on the heterogeneity of the distribution of heavy sand minerals for the fine and very fine sand classes as well as for the surface and subsurface layers. The results showed that the heavy sand minerals that were determined according to the specific gravity of each mineral and the specific gravity of the particles of minerals identified in the soils under study ranged between (2.5–4.5) and were divided into four groups in terms of the specific gravity. The first group included each of the minerals (Mica and Chlorite) of low specific gravity, while the second group contains (Pyroxene, Amphibole, Epidote Group). The third group includes minerals (Tourmaline and Garnet, Staurolite and Kyanite) and the two groups are classified as minerals of medium-specific gravity; in turn, the fourth group contains minerals of high specific gravity, namely (Zircon, Rutile and Opaques). As a result, the most important factors affecting the sedimentation, sorting and sedimentation processes are the conveyor’s speed, load capacity, the size of the separation particles and their specific gravity. The complete mismatch of the horizontal distribution of the minerals of one group is due to the varying ranges of the specific gravity of the minerals within the general range of specific gravity.
Źródło:
Journal of Ecological Engineering; 2023, 24, 7; 318--330
2299-8993
Pojawia się w:
Journal of Ecological Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Enhancing filtration rate of new valley oxidized phosphate concentrate with additives
Autorzy:
Abdel-Aal, E.-S.
Abdel Rahman, E.
Kandil, A.-H.
Powiązania:
https://bibliotekanauki.pl/articles/110175.pdf
Data publikacji:
2016
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
New Valley phosphate concentrate
surfactant
filtration rate
gypsum morphology
crystal size distribution
Opis:
Phosphoric acid is utilized for production of fertilizers. It is mainly produced by wet processes, in which phosphate concentrate, produce by several operations including crushing, scrubbing, classification, attritioning, and desliming, is leached with sulfuric acid with coproduction of calcium sulfate dihydrate (phosphogypsum). The New Valley oxidized phosphate concentrate was processed for phosphoric acid production by addition of certain additives to improve gypsum filtration through modifying its morphology and particle size distribution. The additives used were cetylpyridinium chloride (CPC) as a cationic surfactant, sodium dodecyl sulfate (SDS) as an anionic surfactant and sulfonic acid (SA). The applied dosages ranged from 0.25 to 2.5 kg additive/Mg P2O5 in the phosphate concentrate. The filtration rate of the New Valley oxidized phosphate concentrate is 3.6 Mg P2O5 /m2day without additives. The filtration rate was increased by 33% and 31% with 1 and 0.8 kg/Mg P2O5 doses of CPC surfactant and sulfonic acid (SA), respectively. On the other hand, the filtration rate was decreased by 33% with addition of 1 kg/Mg P2O5 dose of SDS. The aspect ratios of gypsum crystals were 6:1, 3:1, 3:1 and 12:1 without additive, with CPC, SA and SDS surfactant, respectively. Reaction efficiencies without and with 0.8 kg/Mg P2O5 of CPC, SA and SDS dose of additives were 95.0%, 97.9%, 97.9% and 94.7%, respectively. The P2O5 recoveries without and with 0.8 kg/Mg P2O5 of CPC, SA and SDS dose of additives were 92.6%, 95.5%, 95.8% and 90.8%, respectively.
Źródło:
Physicochemical Problems of Mineral Processing; 2016, 52, 1; 124-135
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Travelling wave solutions of the non-linear wave equations
Autorzy:
Haider, Jamil A.
Rahman, Jamshaid U.
Zaman, Fiazud D.
Gul, Sana
Powiązania:
https://bibliotekanauki.pl/articles/2204690.pdf
Data publikacji:
2023
Wydawca:
Politechnika Białostocka. Oficyna Wydawnicza Politechniki Białostockiej
Tematy:
nonlinear evolution problems
coupled equations
Jacobi elliptic functions
periodic solutions
Opis:
This article focuses on the exact periodic solutions of nonlinear wave equations using the well-known Jacobi elliptic function expansion method. This method is more general than the hyperbolic tangent function expansion method. The periodic solutions are found using this method which contains both solitary wave and shock wave solutions. In this paper, the new results are computed using the closed-form solution including solitary or shock wave solutions which are obtained using Jacobi elliptic function method. The corresponding solitary or shock wave solutions are compared with the actual results. The results are visualised and the periodic behaviour of the solution is described in detail. The shock waves are found to break with time, whereas, solitary waves are found to be improved continuously with time.
Źródło:
Acta Mechanica et Automatica; 2023, 17, 2; 239--245
1898-4088
2300-5319
Pojawia się w:
Acta Mechanica et Automatica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optimizing Dry Ultrafine Grinding of Talc in Attritor Mill
Optymalizacja ultradrobnego mielenia talku na sucho w młynie Attritor
Autorzy:
El-Mofty, Salah E.
Elbendari, A. M.
El-Midany, A. A.
Abdel-Rahman, M. K.
Powiązania:
https://bibliotekanauki.pl/articles/27323304.pdf
Data publikacji:
2023
Wydawca:
Polskie Towarzystwo Przeróbki Kopalin
Tematy:
dry grinding
ultra-fine grinding
attritor mill
statistical design
talc
mielenie na sucho
mielenie ultradrobne
młyn attritor
projektowanie statystyczne
talk
Opis:
In this work, the parameters affecting the dry grinding of talc in the attritor mill were investigated. The attritor was tested with its initial design without balls then with balls as additional grinding media to prepare a feed passing 45 microns. The prepared feed (-45 mm) was used to produce a product with 10 μm or less using statistical design in presence of balls. The presence of balls enhances product fineness. The significance of the studied factors is: stirrer speed>mill filling >grinding time. In addition, the d50 was correlated with studied factors. The mean particle size (d50) as low as 6 μm was obtained at 460 rpm, 20% mill filling, and after 60 min grinding time.
W niniejszej pracy zbadano parametry wpływające na mielenie talku na sucho w młynie Attritor. Attritor został przetestowany w początkowej wersji bez kulek, a następnie z kulkami jako dodatkowym medium mielącym w celu przygotowania nadawy przechodzącej przez 45 mikronów. Przygotowany wsad (-45 mm) został wykorzystany do wytworzenia produktu o uziarnieniu 10 μm lub mniejszym przy użyciu statystycznego projektu w obecności kulek. Obecność kulek zwiększa stopień rozdrobnienia produktu. Znaczenie badanych czynników to: prędkość mieszadła > wypełnienie młyna > czas mielenia. Ponadto d50 był skorelowany z badanymi czynnikami. Średni rozmiar cząstek (d50) tak niski jak 6 μm uzyskano przy 460 obr/min, 20% wypełnieniu młyna i po 60 min mielenia.
Źródło:
Inżynieria Mineralna; 2023, 2; 361--366
1640-4920
Pojawia się w:
Inżynieria Mineralna
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An embedded beamformer for a PID-based trajectory sensing for an autonomous vehicle
Autorzy:
Mvemba, P. K.
Lay-Ekuakille, A.
Kidiamboko, S.
Rahman, M. Z. U.
Powiązania:
https://bibliotekanauki.pl/articles/221802.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
autonomous vehicle
beamforming
trajectory follower
ultrasonic obstacle detector
measurement
sensors
Opis:
Beamforming is an advanced signal processing technique used in sensor arrays for directional signal transmission or reception. The paper deals with a system based on an ultrasound transmitter and an array of receivers, to determine the distance to an obstacle by measuring the time of flight and - using the phase beamforming technique to process the output signals of receivers for finding the direction from which the reflected signal is received - locates the obstacle. The embedded beam-former interacts with a PID-based line follower robot to improve performance of the line follower navigation algorithm by detecting and avoiding obstacles. The PID (proportional-integral-derivative) algorithm is also typically used to control industrial processes. It calculates the difference between a measured value and a desired set of points, then attempts to minimize the error by adjusting the output. The overall navigation system combines a PID-based trajectory follower with a spatial-temporal filter (beamformer) that uses the output of an array of sensors to extract signals received from an obstacle in a particular direction in order to guide an autonomous vehicle or a robot along a safe path.
Źródło:
Metrology and Measurement Systems; 2018, 25, 3; 561-575
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Design of a nanoswitch in 130 nm CMOS technology for 2.4 GHz wireless terminals
Autorzy:
Bhuiyan, M. A.
Reaz, M. B. I.
Jalil, J.
Rahman, L. F.
Powiązania:
https://bibliotekanauki.pl/articles/200508.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
CMOS
ISM band
nanometer
transceivers
T/R switch
wireless
Opis:
This paper proposes a transmit/receive (T/R) nanoswitch in 130 nm CMOS technology for 2.4 GHz ISM band transceivers. It exhibits 1.03-dB insertion loss, 27.57-dB isolation and a power handling capacity (P1 dB) of 36.2-dBm. It dissipates only 6.87 μW power for 1.8/0 V control voltages and is capable of switching in 416.61 ps. Besides insertion loss and isolation of the nanoswitch is found to vary by 0.1 dB and 0.9 dB, respectively for a temperature change of 125°C. Only the transistor W/L optimization and resistive body floating technique is used for such lucrative performances. Besides absence of bulky inductors and capacitors in the schematic circuit help to attain the smallest chip area of 0.0071 mm2 which is the lowest ever reported in this frequency band. Therefore, simplicity and low chip area of the circuit trim down the cost of fabrication without compromising the performance issue.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2014, 62, 2; 399-406
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effects of climate change on rice production at Khulna District, Bangladesh
Autorzy:
Hossain, N.
Saifullah, A.S.M.
Bhuiyan, S.H.
Uddin, N.
Rahman, M.
Powiązania:
https://bibliotekanauki.pl/articles/2049750.pdf
Data publikacji:
2019
Wydawca:
Fundacja na Rzecz Młodych Naukowców
Tematy:
rice
production
climate change
trend analysis
Bangladesh
gross domestic product
Mann-Kendall (MK) test
Rice Production
Opis:
In Bangladesh 164 million people depend on rice but due to climate change (CC) vulnerabilities the yield of rice is severely reducing. Therefore, this study aimed to explore the effects of CC on rice yield using recent trend analysis, Mann-Kendall (MK) trend test and correlation. For this study, the required climate and selected rice production data were collected from Bangladesh Meteorological Department (BMD) and Department of Agriculture Extension (DAE), Khulna. In time series statistics both parametric and nonparametric methods were applied to detect a monotonic trend of climatic variability and Aman rice production. Correlation between climatic variability and rice production was also investigated. The study exposed that the temperature and rainfall had an increasing trend and statistically significant whereas the relative humidity found decreasing. Overall, the bright Sunshine had positive trend but week. According to nonparametric trend test of climatic variability and Aman yield only minimum temperature showed a positive trend which found statistically significant. In contrast, Mann-Kendall trend test revealed that rainfall had positively significant while temperature had negative significant. The correlation revealed the Aman production is a strong response with minimum temperature whereas the Lona Coche showed a positive correlation with maximum temperature. The variation of Aman production exhibited a positive correlation with both Rainfall and humidity respectively and Lona Coche found a negative correlation. The sunshine had a week correlation against both yields. The findings suggest should give attention of temperature-tolerant rice varieties to mitigate possible adverse effects of CC.
Źródło:
Environment, Earth and Ecology; 2019, 3, 1; 42-54
2543-9774
2451-4225
Pojawia się w:
Environment, Earth and Ecology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Factors Affecting the Performance of Double Chamber Microbial Fuel Cell for Simultaneous Wastewater Treatment and Power Generation
Autorzy:
Khan, M.R.
Amin, M.S.A.
Rahman, M.T.
Akbar, F.
Ferdaus, K.
Powiązania:
https://bibliotekanauki.pl/articles/779340.pdf
Data publikacji:
2013
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
catholyte
COD
Microbial Fuel Cell
wastewater treatment
Opis:
Electricity generation from the readily biodegradable organic substrate (glucose) accompanied by decolorization of azo dye was investigated using a two-chamber microbial fuel cell (MFC). Batch experiments were conducted to study the effect of dye and substrate concentration on MFC performance. Electricity generation was not signifi cantly affected by the azo dye at 300 mg/L, while higher concentrations inhibited electricity generation. The chemical oxygen demand (COD) removal and decolorization of dye containing wastewater used in the MFC were studied at optimum operation conditions in anode and cathode, 57% COD removal and 70% dye removal were achieved. This study also demonstrated the effect of different catholyte solutions, such as KMnO4 and K2Cr2O7 on electricity generation. As a result, KMnO4 solution showed the maximum electricity generation due to its higher standard reduction potential.
Źródło:
Polish Journal of Chemical Technology; 2013, 15, 1; 7-11
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Structured Analysis of Nanostructured Zinc Oxide (ZnO) Thin Films Deposited by Sol-Gel
Autorzy:
Hussin, Rosniza
Hanafi, F.
Rashid, R. A.
Harun, Z.
Kamdi, Z.
Ibrahim, S. A.
Ainuddin, A. R.
Rahman, W.
Leman, A. M.
Powiązania:
https://bibliotekanauki.pl/articles/2134100.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
sol-gel
zinc oxide
ZnO
thin films
nanostructured
Opis:
In this work, zinc oxide (ZnO) thin films are deposited on glass substrate using the sol-gel spin coating technique. The effect of annealing temperature on structural properties was investigated. The ZnO sol-gel was produced from zinc acetate dehydrate as the starting material with iso-propanol alcohol as the stabilizer. The ratio was controlled, distilled water and diethanolamine as the solvent mixing on a magnetic stirrer for an hour under constant heat of 60°C. The ZnO thin film was deposited using the spin coating technique with the speed of 3000 rpm for 30 minutes before the sample undergoes pre-heat in the oven at the temperature of 100°C for 10 minutes. The sample was annealing in the furnace for an hour at 200°C, 350°C, and 500°C. The X-ray diffraction (XRD) analysis confirms that hexagonal wurtzite structure with zincite and zinc acetate hydroxide hydrate composition. The thin films surface roughness was analyzed using an atomic force microscope (AFM) and scanning electron microscope (SEM) for surface morphology observation.
Źródło:
Archives of Metallurgy and Materials; 2022, 67, 3; 1055--1060
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Factors contribution to the adoption of production technologies by potato growers in northwest Bangladesh
Wpływ różnych czynników na dobór technologii produkcji ziemniaków w północno-zachodnim Bangladeszu
Autorzy:
Uddin, A.B.M.S.
Rahman, M.M.
Alam, M.B.
Kamaly, M.H.K.
Powiązania:
https://bibliotekanauki.pl/articles/44076.pdf
Data publikacji:
2014
Wydawca:
Uniwersytet Przyrodniczy w Poznaniu. Wydawnictwo Uczelniane
Źródło:
Journal of Agribusiness and Rural Development; 2014, 33, 3
1899-5241
Pojawia się w:
Journal of Agribusiness and Rural Development
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Chitosan biostimulant controls infection of cucumber by Phytophthora capsici through suppression of asexual reproduction of the pathogen
Biostymulant chitozan kontroluje zakażenie ogórka przez Phytophthora capsici poprzez hamowanie bezpłciowego rozmnażania patogen
Autorzy:
Zohara, F.
Surovy, M.Z.
Khatun, A.
Prince, F.R.K.
Ankada, A.M.
Rahman, M.
Islam, T.
Powiązania:
https://bibliotekanauki.pl/articles/27828.pdf
Data publikacji:
2019
Wydawca:
Polskie Towarzystwo Botaniczne
Opis:
The biopolymer chitosan is a derivative of chitin, which can promote plant growth and protect plants from phytopathogens. This study aimed to evaluate the efficacy of chitosan as a biostimulant and a biorational agent to protect cucumber plants from damping-off disease caused by Phytophthora capsici. Cucumber seeds were treated with a range of chitosan concentrations, viz. 0, 125, 250, and 500 ppm, to evaluate effect on seed germination and fresh root and shoot weight of the seedlings. Chitosan significantly (p ≤ 0.05) enhanced seed germination and root and shoot growth of cucumber in a dose-dependent manner up to 500 ppm. Application of in vitro chitosan suspension onto P. capsici mycelial plug suppressed growth of mycelia, formation of sporangia, and release of P. capsici zoospores at 125–500 ppm concentrations. Cucumber seedlings from chitosan-treated seeds showed enhanced resistance to damping-off disease caused by P. capsici compared to untreated control. Cucumber seedlings from 500 ppm chitosan seed treatment showed 100% disease resistance against damping off caused by P. capsici. These results suggest that chitosan could be used as a natural and environmentally safe alternative to a synthetic growth promoter and pesticide for sustainable production of cucumber.
Biopolimer chitozan jest pochodną chityny, może on stymulować wzrost roślin i chronić je przed fitopatogenami. Celem badań była ocena skuteczności chitozanu jako biostymulatora i „bioracjo-nalnego” środka ochrony ogórka przed zgorzelą wywołaną przez Phytophthora capsici. Nasiona ogórka poddano działaniu różnych stężeń chitozanu tj. 0, 125, 250 i 500 ppm w celu oceny ich wpływu na kiełkowanie nasion oraz świeżą masę korzeni i pędów siewek. Chitozan istotnie (p ≤ 0,05) stymulował kiełkowanie nasion oraz wzrost korzeni i pędów ogórka w sposób zależny od dawki do 500 ppm. Zastosowanie zawiesiny chitozanu w zakresie stężeń 125–500 ppm w warunkach in vitro hamowało wzrost grzybni P. capsici, tworzenie sporangiów i uwalnianie zoospor P. capsici. Siewki roślin uzyskanych z nasion traktowanych chitozanem charakteryzowały się zwiększoną odpornością na zgorzel wywołaną przez P. capsici w porównaniu z nietraktowanych chitozanem. Siewki ogórków z nasion traktowanych 500 ppm chitozanu wykazywały 100% odporność na zgorzel powodowaną przez P. capsici. Wyniki te sugerują, że chitozan może być stosowany jako naturalna i bezpieczna dla środowiska alternatywa dla syntetycznych stymulatorów wzrostu oraz pestycydów w zrównoważonej produkcji ogórka.
Źródło:
Acta Agrobotanica; 2019, 72, 1
0065-0951
2300-357X
Pojawia się w:
Acta Agrobotanica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fruit yield and quality of ‘Florida King’ peaches subjected to foliar calcium chloride sprays at different growth stages
Autorzy:
Shahid, M.O.
Muhmood, A.
Ihtisham, M.
Rahman, M.ur
Amjad, M.
Sajid, M.
Riaz, K.
Ali, A.
Powiązania:
https://bibliotekanauki.pl/articles/12704034.pdf
Data publikacji:
2020
Wydawca:
Uniwersytet Przyrodniczy w Lublinie. Wydawnictwo Uniwersytetu Przyrodniczego w Lublinie
Opis:
Peach fruit and trees are prone to various issues, regarding yield, quality and pest attack. Calcium plays several roles in plant and fruit development. Therefore the current study was conducted to evaluate the response of peach fruit to foliar application. The experiment was laid out in Randomized Complete Block Design with two factors factorial arrangement and three replicates. Calcium chloride was applied at the rate of 0, 1, 2 and 3%. The foliar application of calcium was done at pink bud stage, berry size fruit stage, and then at pit hardening stage of peach. The obtained results indicated that foliar application of calcium significantly improved peach fruit quality and yield. The highest fruit weight (142.6 g), yield tree⁻¹ (15.6 kg), ascorbic acid content (6.67 mg∙100 g⁻¹), total soluble solids (11.0°Bx), fruit juice pH (3.98), sugar to acid ratio (45.1), fruit firmness (3.90 kg∙cm⁻²) and fruit volume (155.6 cm³) was obtained with the application of 3% solution of calcium chloride at pit hardening stage but it significantly reduced the percent titratable acidity (0.3%) and disease incidence (5.8%). It was concluded that 3% calcium chloride applied at the pit hardening stage significantly boosted peach quality and fruit yield.
Źródło:
Acta Scientiarum Polonorum. Hortorum Cultus; 2020, 19, 1; 131-139
1644-0692
Pojawia się w:
Acta Scientiarum Polonorum. Hortorum Cultus
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Diurnal seismic ambient noise and seismic station performance characterization in the Bengal Basin, Bangladesh
Autorzy:
Zannat, Naharin
Farazi, Atikul Haque
Kamal, A. S. M. Maksud
Rahman, Md. Zillur
Hossain, Md. Shakhawat
Powiązania:
https://bibliotekanauki.pl/articles/27310143.pdf
Data publikacji:
2023
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
seismic ambient noise
power spectral density
noise energy
noise sources
seismic station
Bengal Basin
Opis:
Seismic ambient noise (SAN) energy can potentially blur regional and teleseismic arrivals as well as various microearthquakes at specific frequencies. Therefore, quantification of the SAN energy level in a region is required to optimize seismic station distribution for seismological investigations. Moreover, evaluation of station performance and noise source is possible from observation of SAN energy levels. The SAN energy distribution from seismic stations in the Bengal Basin (BB), Bangladesh has not yet been estimated. At the same time, this tec-tonically active and complex region is less studied using seismic methods. This study aims to quantify SAN ener-gy and characterize its diurnal variation along with evaluating station performance at 11 seismic stations, which were temporarily installed in the deeper portion of the BB. Herein, the daily SAN energy level was determined within the period range of 0.02–30 s by estimating the power spectral density (PSD) of seismic data for 7 continu-ous days. SAN energy and its variation over time were observed using the probability density functions (PDFs) of PSDs and spectrograms, respectively. The sources of SAN energies at different period bands were also investigat-ed by comparing the PSDs with daily variations in human activities, nearby noise sources, local meteorological factors (i.e., air temperature and precipitation), and sea level height. The insights from this study could be useful for the future deployment of seismic networks as well as seismological studies in the BB.
Źródło:
Geology, Geophysics and Environment; 2023, 49, 3; 209--224
2299-8004
2353-0790
Pojawia się w:
Geology, Geophysics and Environment
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dosimetry of 131 I for Occupational Radiation Workers by Whole Body Counting System
Autorzy:
Rahman, M. S.
Haydar, M. A.
Patwary, M. K. A.
Shome, S. M.
Paul, S.
Paul, D.
Meaze, A. K. M. M. H.
Powiązania:
https://bibliotekanauki.pl/articles/411910.pdf
Data publikacji:
2014
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Internal Dosimetry
Whole Body Counter
IMBA
131I
Opis:
Internal radiation dosimetry of occupational radiation workers due to inhalation of 131 I during maintenance at iodine 131 I hot cell of Radioisotope Production Division (RIPD) of Bangladesh Atomic Energy Commission have been performed with Whole Body Counter (WBC) containing two large size NaI detector. The contaminated radioactivity of the radiation workers by 131 I was immediately conducted using a WBC (CANBERRA, FASTSCAN model 2250) and counting was repeated again a few days later. The performance of whole body counter was checked by CANBERRA transfer phantom (model 2257) with a mixed source (20 ml vial). The intake was calculated by Apex-Invivo counting software and then corresponding dose in thyroid were estimated by using Integrated Modules for Bioassay Analysis (IMBA) Professional Plus code modules. The body activity due to intake of 131 I and the total effective and equivalent dose in thyroid were also estimated and discussed.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2014, 20, 1; 21-27
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Development of High Entropy Alloy as Catalyst for Azo Dye Degradation in Fenton Process
Autorzy:
Hassan, Nur Hudawiyah Abu
Nasir, Nisa Syukrina Mat
Rahman, S. N. A.
Irfan, Abd Rahim
Nordin, Norhuda Hidayah
Powiązania:
https://bibliotekanauki.pl/articles/2203739.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
azo dye
catalyst
fenton process
high entropy alloys
HEAs
Opis:
Azo dye is widely used in the textile industry since it is cost effective and simple to use. However, it becomes a continuous source of environmental pollution due to its carcinogenicity and toxicity. Various methods had been used to remove the azo dye in solution. One of the famous and frequently used is the Fenton process. The Fenton process is one of the advanced oxidation processes where iron catalysed hydrogen peroxide to generate hydroxyl radical. Treating azo dyes in solution requires a catalyst to enhance the process of degradation. Herein, high entropy alloys (HEAs) have been proposed as a catalytic material to enhance the performance of Fenton process for azo dye degradation. HEAs have been reported as a promising catalyst due to its high surface area. The higher the number of active sites, the higher the rate of azo dye degradation as more active sites are available for adsorption of azo dyes. The results have shown that HEAs can be used as a catalyst to fasten the Fenton reaction since the degradation time is proven to be shorter in the presence of HEAs. The method derived from the result of this study will contribute in treating azo dyes for wastewater management in the Fenton process.
Źródło:
Archives of Metallurgy and Materials; 2023, 68, 1; 209--213
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Removal of Cadmium using Alkaline-Treated Activated Carbon from Leucaena Leucocephala Biomass
Autorzy:
Ibrahim, W. M. H. W.
Sulaiman, Nurul Syuhada
Amini, Mohd Hazim Mohammad
Kadir, W. R. A.
Mohamed, Mazlan
Ramle, Sitti Fatimah Mhd
Bilgin, Ugur
Rahman, Wan
Powiązania:
https://bibliotekanauki.pl/articles/2125550.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
activated carbon
cadmium
Leucaena leucocephala
adsorption
Opis:
Water contamination that caused by heavy metals is a very common phenomenon in the industrial age. One of the popular way to treat metal contaminated water is by adsorption process using activated carbon as the adsorbent. This paper works on producing activated carbon by chemical means with impregnation ratios of NaOH:char (w/w) was predetermined at 1:1 (ACT1-1), 2:1 (ACT2-1) and 3:1 (ACT3-1) under activation temperature of 700°C. Considering the Leucaena leucocephala is a wildly, easy and fast grown species, with the availability throught the year, it was chosen to be used as the precursor. The properties of these activated carbons and its potential for cadmium removal from aqueus solution was analyzed. It was found that the highest surface area was recorded at 662.76 m²/g. Four parameters were studied which are contact time, the effect of pH, initial concentration of adsorbate and temperature. The equilibrium time was achieved in 40 min treatment at initial concentrations of 30 mg/l. The adsorbent exhibited good sorption potential for cadmium at pH 8.0 and equilibrium temperature of 30℃. Based on the results, this study had proved that activated carbon from Leucaena leucocephala biomass have the good potential to be used for removal of cadmium from wastewater.
Źródło:
Archives of Metallurgy and Materials; 2022, 67, 3; 1033--1036
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Evaluating the Total Phenolic, Protein Contents, Antioxidant and Pharmacological Effects of Cynodon dactylon Extracts Against Escherichia coli and Staphylococcus aureus
Autorzy:
Ibrahim, Muhammad
Riaz, Moazama
Ali, Akbar
Shaheen, Musarat
ur Rahman, Shafiq
Aziz, Riffat
Alamri, Abdulhakeem S.
Alhomrani, Majid
Dablool, Anas S.
Alghamdi, Saad
Sameeh, Manal Y.
Tashkandi, Manal A.
Powiązania:
https://bibliotekanauki.pl/articles/27315658.pdf
Data publikacji:
2023
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
Cynodon dactylon
Anti-microbial
Flavonoids
Total Soluble Proteins
Peroxidase
Antioxidant
Super oxide Dismutase
Opis:
The study was aimed to characterize the antioxidant and anti-microbial activities of Cynodon dactylon with special reference on its precise biochemical analysis. Physiological analysis that total carotenoids content (0.3884 ± 0.0172 mg/g), total chlorophyll content (6.1460 ± 0.2915 mg/g), total phenolic contents (13.4703 ± 0.1494 mg/g), chlorophyll a (3.7708 ± 0.1528 mg/g, catalase (CAT) contents (40.2844 ± 0.1515 units/ mg), total anthocyanin contents (5.0166 ± 0.2966 g–1 FW) total soluble proteins (2.9916 ± 0.1734 mg/g) and total flavonoids content (TFC) (4.7863 ± 0.0442 μg/g) was found higher in the leaves of the Cynodon dactylon whereas, chlorophyll b (2.4881 ± 0.1326 mg/g) was found higher in the stem of Cynodon dactylon, while, peroxidase (POD) contents (81.8763 ± 4.6609 units/mg) and superoxidase dismutase (SOD) activity (80.4346 ± 5.9367 units/mg) was investigated higher in roots of Cynodon dactylon. The anti-microbial activity of Cynodon dactylon extracts was performed using a good diffusion technique against two microbial strains. Among all the plant extracts, the methanolic extracts showed a maximum inhibition zone (26.87 mm) against anti-bacterial strain Escherichia coli whereas n-hexane extract showed a maximum inhibition zone (17.88 mm) against anti-fungal strain Candida albicans. This study reported the antimicrobial activity of Cynodon dactylon against some common pathogens such as Staphylococcus aureus, Escherichia coli, and Candida albicans, which are highly associated with nosocomial infection. From the given results it is concluded that Cynodon dactylon could be exploited in pharmacology due to its antioxidant and anti-microbial properties.
Źródło:
Polish Journal of Chemical Technology; 2023, 25, 3; 110--119
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
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