Autor: Ali, R. A. - Katalog OPAC zbiorów

Skocz do pozycji: 1.

Tytuł:: Effect of Substrate Temperature on Structural and Optical Properties of CdO Thin Films
Autorzy:: Ali, H. R. A.
Powiązania:: https://bibliotekanauki.pl/articles/411893.pdf
Data publikacji:: 2014
Wydawca:: Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:: cadmium oxide
spray pyrolysis technique
XRD
AFM
thin films
sol-gel
Opis:: Thin films of CdO have been prepared by spray pyrolysis technique. XRD analysis reveals that all the prepared samples were polycrystalline and have preferred orientation along [111] orientation. The surface topography was determined by AFM which indicate that surface roughness and rms roughness were increased by the increasing of substrate temperature. The optical energy gap were determined and its value lies between (2.4-2.5) eV.
Źródło:: International Letters of Chemistry, Physics and Astronomy; 2014, 8; 47-55
2299-3843
Pojawia się w:: International Letters of Chemistry, Physics and Astronomy
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 2.

Tytuł:: The effect of working capital management on SMEs profitability in Malaysia
Wpływ zarządzania kapitałem pracy na rentowność MŚP w Malezji
Autorzy:: Gorondutse, A. H.
Ali, R. A.
Abubakar, A.
Naalah, M. N. I.
Powiązania:: https://bibliotekanauki.pl/articles/405447.pdf
Data publikacji:: 2017
Wydawca:: Politechnika Częstochowska
Tematy:: working capital
working capital management
SMEs
profitability
Malaysia
kapitał obrotowy
zarządzanie kapitałem obrotowym
MŚP
rentowność
Malezja
Opis:: The paper examines the effects of working capital management on Malaysian SMEs profitability within the sight of control factors measured by the size of the firm, leverage, and sales growth. Secondary data was drowned from Companies Commission of Malaysia, database for 66 SMEs in Malaysia for the period between 2006-2012. Panel data regressions were applied in the analysis. Empirical results established a negative effect of working capital administration measures: Stock Turnover in Days, Days Account Receivables, and Cash Conversion Cycle on SMEs benefit intermediaries, Return on Equity (ROE) and Return on Assets. The results also established a positive effect of Net Operating Profit on Cash Conversion Cycle. Furthermore, the study also revealed a positive effect of Days Account Payables on SME’s Return of Asset and Return of Equity, yet having a negative effect on Net operating Profit. The findings imply that profitability of Malaysian SMEs relies upon effective working capital management. The results imply that Profitability of Malaysian SMEs depends upon effective working capital management. The paper contributes empirical evidence on the effect of working capital on Malaysian SMEs.
Artykuł analizuje wpływ zarządzania kapitałem obrotowym na rentowność w MŚP Malezji pod kątem czynników kontrolnych mierzonych wielkością firmy, dźwignią finansową i wzrostem sprzedaży. Wtórne dane zostały uzyskane z Komisji Firm Malezji, bazy danych dla 66 MŚP w Malezji w latach 2006-2012. W analizie zastosowano regresję danych panelowych. Wyniki empiryczne wykazały negatywny wpływ narzędzi zarządzania kapitałem obrotowym: rotacja zapasów w dniach, należności z tytułu dni płatniczych i cykl konwersji gotówki do pośrednikach świadczeń MŚP, zwrot z kapitału własnego i zwrot z aktywów. Wyniki wykazały również pozytywny wpływ operacji netto. Ponadto, badanie wykazało również pozytywny wpływ zobowiązań z tytułu płatności w dniach na zwroty aktywów i zwrotu kapitałów własnych MŚP, co jednak ma negatywny wpływ na zysk netto z działalności operacyjnej. Wyniki badania sugerują, że rentowność malezyjskich MŚP zależy od Zarządzania kapitałem obrotowym. Wyniki sugerują, że rentowność malezyjskich MŚP zależy od skutecznego zarządzania kapitałem obrotowym. Artykuł ten stanowi dowód empiryczny na temat wpływu kapitału obrotowego na malezyjskie MŚP.
Źródło:: Polish Journal of Management Studies; 2017, 16, 2; 99-109
2081-7452
Pojawia się w:: Polish Journal of Management Studies
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 3.

Tytuł:: Numerical thermo-mechanical strength analysis of an IC engine component
Autorzy:: Ali, M. A. N.
Hussein, R. A.
Hussein, H. A.
Powiązania:: https://bibliotekanauki.pl/articles/2106442.pdf
Data publikacji:: 2021
Wydawca:: Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:: analiza numeryczna
silnik spalinowy
naprężenie
trwałość zmęczeniowa
numerical analysis
IC engine piston
geometrical shape
thermo-mechanical strength
stress intensity
fatigue life
Opis:: This research investigates a thermo-mechanical strength of three geometrical shape designs of an internal combustion (IC) engine piston by a finite element analysis (FEA). FEA was performed using Solidworks software for modelling geometrical piston designs, and the models were imported into ANSYS software for thermo-mechanical fatigue simulation. The work focused on predicting high stress intensity and indicated the fatigue critical regions and life of the piston shape design. AL7075-T6 aluminium alloy was used as a piston material and thermo-mechanical fatigue simulation was conducted based on the experimental stress-number of cycles recorded data from literature. Analytical results showed the similarity of the critical failure positions to some real failures in the IC engine piston, and the shape design modification of the piston. Hence, this concept can be used to satisfy the IC engine design needs at low cost.
Źródło:: International Journal of Applied Mechanics and Engineering; 2021, 26, 3; 1--11
1734-4492
2353-9003
Pojawia się w:: International Journal of Applied Mechanics and Engineering
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 4.

Tytuł:: Assessment of construction workers’ hydration status using urine specific gravity
Autorzy:: Montazer, Saideh
Farshad, Ali A.
Monazzam, Mohammad R.
Eyvazlou, Meysam
Yaraghi, Ali A.
Mirkazemi, Roksana
Powiązania:: https://bibliotekanauki.pl/articles/2179079.pdf
Data publikacji:: 2013-10-01
Wydawca:: Instytut Medycyny Pracy im. prof. dra Jerzego Nofera w Łodzi
Tematy:: thermal stress
dehydration
USG
TWL
Opis:: Objectives: The study objective was to assess hydration status by measuring USG among construction workers in Iran. Materials and Methods: The study design was comparative and experimental. Sixty participants were randomly selected from the construction workers from a construction campus with a similar type of work, climate and diet and formed 2 groups (individuals exposed to the sun and non-exposed individuals). TWL and USG were measured in both groups on 2 consequent days, at the beginning, mid and end of the work shift. Results: USG test showed that mean USG was 1.0213±0.0054 in the control group and in the exposed group, where it was significantly higher, it amounted to 1.026±0.005. In the exposed group, 38% of workers had a USG level between 1.026-1.030, representing a higher risk of heat illness and impaired performance and 12.72% had a USG level above 1.030 representing a clinically dehydrated status, while this proportion in the control group was 15.2% and 0.58%, respectively. The mean TWL index measure was 215.8±5.2 W/m² for the control group and 144±9.8 W/m² for the exposed group, where, again, it was significantly higher. The Pearson correlation measure showed a significant correlation between USG and TWL. Conclusions: Strong correlation between TWL, as an indicator of thermal stress and USG shows that USG can be considered as a predictor of thermal stress. The difference between USG among the exposed and non-exposed workers and the increase in USG during midday work show the sensitivity of this measure in different thermal and climatic conditions, whereas, the high level of dehydration among workers despite acceptable TWL level, shows that heat stress management without considering the real hydration status of workers, is insufficient.
Źródło:: International Journal of Occupational Medicine and Environmental Health; 2013, 26, 5; 762-769
1232-1087
1896-494X
Pojawia się w:: International Journal of Occupational Medicine and Environmental Health
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 5.

Tytuł:: Studying the effect of some parameters on the stability of shallow tunnels
Autorzy:: Abdellah, W. R.
Ali, M. A.
Yang, H.-S.
Powiązania:: https://bibliotekanauki.pl/articles/92102.pdf
Data publikacji:: 2018
Wydawca:: Główny Instytut Górnictwa
Tematy:: tunnel shape
rock joint
numerical modelling
stability indicator
kształt tunelu
przełom skał
modelowanie numeryczne
wskaźnik stabilności
Opis:: Several factors have crucial impact on the serviceability of underground openings including: the quality of rock mass; the presence of rock joints and their geometrical properties; the state of in-situ stress ratio; the depth below surface and opening geometry. This paper only investigates the effect of two parameters on the stability of underground shallow tunnels, namely: the presence of rock joints in the rock mass matrix and the shape of the excavation. A series of two-dimensional elasto-plastic finite-element models has been constructed using rock-soil, RS2D, software. Consequently, parametric stability analysis has been conducted for three different tunnel shapes (e.g. circular, square and horseshoe) with/without joint inclusion. Four reference points have been assigned in the tunnel perimeter (e.g. back, sidewalls and floor) to monitor the state of stress-displacement in the rock mass around them. The results indicate that the weak performance of a tunnel opening occurs with a square-shaped opening and when joints exist in the rock mass. In addition, the normal stress along joints sharply drops in the vicinity of a tunnel opening. Moreover, the direction of shear stress is reversed. Thus, it causes inward shear displacement.
Źródło:: Journal of Sustainable Mining; 2018, 17, 1; 20-33
2300-1364
2300-3960
Pojawia się w:: Journal of Sustainable Mining
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 6.

Tytuł:: Maintenance and management of wastewater system components using the condition index system, prediction process and costs estimation
Konserwacja i zarządzanie systemem kanalizacji ściekowej za pomocą systemu wskaźnika stanu, procesu przewidywania i szacowania kosztów
Autorzy:: Amani, N.
Ali, N. M.
Mohammed, A. H.
Samat, R. A.
Powiązania:: https://bibliotekanauki.pl/articles/302164.pdf
Data publikacji:: 2013
Wydawca:: Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:: proces zarządzania konserwacją
instalacja
optymalizacja
analiza kosztów
studium przypadku
maintenance management process
component
optimization
cost analysis
case study
Opis:: Component maintenance management of public building is complex and dynamic as the execution of the engineering management system is subjected to sensitive staff and users' requirements and high expectation of the top management for supporting the business. This paper presents the practices and survey need for maintaining the facilities systems in the building. The purpose of this study is maintenance time optimization of building component using the USACERL condition index (CI) system. To achieve this objective, cast iron pipe within wastewater plumbing system is surveyed using the financial analysis for implementation of optimal maintenance time based on limited cost. The findings show how a best time approach to plumbing system maintenance can assist the owner for decision making in component maintenance time based on existing cost.
Zarządzanie konserwacją instalacji budynku publicznego jest złożone i dynamiczne z uwagi na fakt, iż realizacja systemu zarządzania technicznego poddana jest zarówno wymaganiom personelu i użytkowników końcowych jak i oczekiwaniom kierownictwa w zakresie wsparcia rozwoju przedsiębiorstwa. W niniejszym artykule przedstawiono praktykę oraz badania dotyczące potrzeb wiążących się z konserwacją instalacji w budynkach. Celem tego opracowania jest optymalizacja czasu konserwacji tej części budynku za pomocą systemu wskaźnika stanu (condition index - CI) USACERL. Aby osiągnąć ten cel, przeanalizowano za pomocą analizy finansowej system kanalizacji ściekowej oparty na rurach żeliwnych pod kątem przyjęcia optymalnego czasu obsługi w oparciu o ograniczone koszty. Wyniki pokazują jak optymalne podejście czasowe do konserwacji systemu hydraulicznego może pomóc właścicielowi w procesie podejmowania decyzji w aspekcie czasu konserwacji na podstawie rzeczywistych kosztów.
Źródło:: Eksploatacja i Niezawodność; 2013, 15, 2; 161-168
1507-2711
Pojawia się w:: Eksploatacja i Niezawodność
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 7.

Tytuł:: The effects of climate change on photovoltaic solar production in hot regions
Autorzy:: Al-Baghdadi, Maher A. R. Sadiq
Ridha, Amel A.
Al-Khayyat, Ali Salam
Powiązania:: https://bibliotekanauki.pl/articles/2096200.pdf
Data publikacji:: 2022
Wydawca:: Polska Akademia Nauk. Polskie Towarzystwo Diagnostyki Technicznej PAN
Tematy:: PV cell temperature
PV cell performance
climate change
hot regions
two axis tracking
energia słoneczna
fotowoltaika
zmiana klimatu
dwuosiowy system nadążający
Opis:: The work of solar cells and their production of electrical energy have been affected by climate change, especially in hot regions which became significantly hotter and still receive relatively high levels of solar radiation throughout the year. Higher ambient temperature and solar radiation result in higher PV cell temperature and, therefore, the reduction in PV module power output and efficiency. This study investigates how a PV module performs throughout the year in a hot region by considering the variations in cell temperature resulting from changes in ambient temperature and solar radiation every day. The tilt angles and two-axis tracking have also been examined. Results indicate that the two-axis solar tracking system is critical to use in hot regions for obtaining higher output power. Therefore, part of this power can be used to cool solar panels using various methods to keep their efficiency high, such as operating air fans or operating pumps to cool them with coolant.
Źródło:: Diagnostyka; 2022, 23, 3; art. no. 2022303
1641-6414
2449-5220
Pojawia się w:: Diagnostyka
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 8.

Tytuł:: Impact of Crosstalk into High Resistivity Silicon Substrate on the RF Performance of SOI MOSFET
Autorzy:: Ali, K. B.
Neve, C. R.
Gharsallah, A.
Raskin, J. P.
Powiązania:: https://bibliotekanauki.pl/articles/308378.pdf
Data publikacji:: 2010
Wydawca:: Instytut Łączności - Państwowy Instytut Badawczy
Tematy:: crosstalk
high resistivity Si
mixing products
passivation layer
polysilicon
Opis:: Crosstalk propagation through silicon substrate is a serious limiting factor on the performance of the RF devices and circuits. In this work, substrate crosstalk into high resistivity silicon substrate is experimentally analyzed and the impact on the RF behavior of silicon-on-insulator (SOI) MOS transistors is discussed. The injection of a 10 V peak-to-peak single tone noise signal at a frequency of 3 MHz ( fnoise) generates two sideband tones of ?56 dBm separated by fnoise from the RF output signal of a partially depleted SOI MOSFET at 1 GHz and 4.1 dBm. The efficiency of the introduction of a trap-rich polysilicon layer located underneath the buried oxide (BOX) of the high resistivity (HR) SOI wafer in the reduction of the sideband noise tones is demonstrated. An equivalent circuit to model and analyze the generation of these sideband noise tones is proposed.
Źródło:: Journal of Telecommunications and Information Technology; 2010, 4; 93-100
1509-4553
1899-8852
Pojawia się w:: Journal of Telecommunications and Information Technology
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 9.

Tytuł:: Changes in blood acid-base balance parameters and coagulation profile during diarrhea in calves
Autorzy:: Sobiech, P.
Rekawek, W.
Ali, M.
Targonski, R.
Zarczynska, K.
Snarska, A.
Stopyra, A.
Powiązania:: https://bibliotekanauki.pl/articles/31605.pdf
Data publikacji:: 2013
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Opis:: The purpose of this study was to investigate possible alterations in acid-base balance parameters and the coagulation profile in neonatal diarrheic calves. Twenty neonatal diarrheic and 20 clinically healthy neonatal calves aged between 1 week to 10 days were used. All blood samples were taken on the third day from the onset of diarrhea symptom. Venous blood samples were collected from each animal to determine platelet numbers, pH, pCO₂, pO₂, HCO₃⁻, BE, O₂SAT, ctCO₂ and electrolytes (K⁺, Na⁺ and Cl⁻). Plasma samples were collected from each animal for the measurement of prothrombin time (PT), activated partial thromboplastin time (APTT), thrombin time (TT), the concentrations of fibrinogen, D-dimer and the activity of antithrombin III (AT III). Blood pH (7.19), BE (-10.6 mmol/l), HCO₃⁻ (25.15 mmol/l), pO₂ (3.33 kPa), O₂SAT (24.12 %) were significantly lower and serum concentration of K⁺ (6.55 mmol/l) was significantly higher in diarrheic calves. These changes indicate the state of uncompensated metabolic acidosis with accompanying hyperkalemia. TT (32.05s) and APTT (39.9s) values were more prolonged in calves with diarrhea than in the control group. D-dimer (587.25 μg/l) concentrations were significantly increased while a visible drop in AT III (103.75%) activity and platelets counts (598 x10⁹/l) were observed in diarrheic group of calves. The results suggest that a consumptive type of disseminated intravascular coagulation (DIC) developed in diarrheic calves.
Źródło:: Polish Journal of Veterinary Sciences; 2013, 16, 3
1505-1773
Pojawia się w:: Polish Journal of Veterinary Sciences
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 10.

Tytuł:: Review of mechanical vapour compression refrigeration system part 2: performance challenge
Autorzy:: Mahmood, R. A.
Ali, O. M.
Al-Janabi, A.
Al-Doori, G.
Noor, M. M.
Powiązania:: https://bibliotekanauki.pl/articles/2106451.pdf
Data publikacji:: 2021
Wydawca:: Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:: para
układ chłodniczy
współczynnik wydajności
vapour compression
refrigeration system
cycle
coefficient of performance COP
Opis:: Reducing energy consumption and providing high performance for a vapour compression refrigeration system are big challenges that need more attention and investigation. This paper provides an extensive review of experimental and theoretical studies to present the vapour compression refrigeration system and its modifications that can be used to improve system’s performance and reduce its energy consumption. This paper also presents the challenges that can be considered as a gab of research for the future works and investigations. Cooling capacity, refrigerant effect, energy consumption can be improved by using vapour injection technique, natural working fluid, and heat exchanger. Based on the outcome of this paper, vapour injection technique using natural refrigerant such as water can provide ultimate friendly refrigeration system. Future vision for the vapour compression refrigeration system and its new design technique using Computational Fluid Dynamic (CFD) is also considered and presented.
Źródło:: International Journal of Applied Mechanics and Engineering; 2021, 26, 3; 119--130
1734-4492
2353-9003
Pojawia się w:: International Journal of Applied Mechanics and Engineering
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 11.

Tytuł:: Optimisation of variation coolant system techniques in machining aluminium alloy Al319
Autorzy:: Zainal Ariffin, S.
Efendee, A. M.
Redhwan, A. A. M.
Alias, M.
Arifuddin, A.
Kamrol Amri, M.
Mohd Ali, M.
Khalil, K.
Aminullah, A. R. M.
Hasnain, A. R.
Baba, N. B.
Powiązania:: https://bibliotekanauki.pl/articles/2201047.pdf
Data publikacji:: 2022
Wydawca:: Stowarzyszenie Komputerowej Nauki o Materiałach i Inżynierii Powierzchni w Gliwicach
Tematy:: aluminium alloy 319
coated cemented carbide Al2O3
surface roughness
response surface method
stop aluminium
węglik spiekany powlekany
chropowatość powierzchni
metoda powierzchni odpowiedzi
Opis:: Purpose Cutting parameters are often chosen for machining by machine operators in the industry. The experience and efficiency of the machine operator in producing a quality product are frequently used to decide parameter selection—low productivity results from improper parameter selection, inefficient machining, and technological issues. Today's key issues in the machining industry are focusing on increasing machining performance on surface roughness while minimising coolant usage. The study's objective is to enhance the performance of the nozzle lubrication system during the turning operation of an aluminium alloy 319 workpieces (Al319) to generate good surface roughness by applying turning parameters such as cutting speed, feed rate, and the depth of cut. Design/methodology/approach Response Surface Method (RSM) was used to create the experimental method for this investigation, carried out using a CNC lathe machine with two axial movements and a wet cooling nozzle with a size of 1.0 mm. Synthetic soluble lubricants, Al2O3-coated cemented carbide inserts, and Aluminium alloy 319 were utilised as cutting tools and workpiece materials. Findings To study the influence of cutting parameters on surface roughness, the Analysis of Variance (ANOVA) approach was utilised while the response surface method was performed to achieve an optimum machining performance (RSM). When comparing dry and wet cooling systems, the size of 1.0 mm nozzle shows appropriate surface roughness. According to the ANOVA analysis, the key factor impacting the surface roughness as machining performance in lubrication technique experiments was the utilisation of 1.0 mm nozzle size. Research limitations/implications The findings of combination machining parameters at a cutting speed of 270 m/min and a cutting depth of 0.60 mm at a feed rate of 0.08 mm/min offered the best results, achieving a surface roughness, Ra of 0.94 µm. Practical implications The use of coolant size nozzle 1.0 mm technology combined with the use of correct machining parameters can improve machining cuts. Originality/value The novel size of 1.0 mm nozzle in this current research is also valuable for reducing and increasing productivity in the machining business, as well as reducing dependency on machining operators' experience and abilities.
Źródło:: Journal of Achievements in Materials and Manufacturing Engineering; 2022, 113, 2; 72--77
1734-8412
Pojawia się w:: Journal of Achievements in Materials and Manufacturing Engineering
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 12.

Tytuł:: Comparative analysis of natural nanosilica versus commercial nanosilica on compressive strength and durability of high-performance concrete
Autorzy:: Tjahjani, A.R. Indra
Fulazzaky, Mohamad Ali
Jonbi, Jonbi
Tinumbia, Nuryani
Meutia, Wita
Suraedi, Daral
Ranna, Prima
Powiązania:: https://bibliotekanauki.pl/articles/27312142.pdf
Data publikacji:: 2023
Wydawca:: Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:: nanokrzemionka
materiał naturalny
materiał komercyjny
wytrzymałość na ściskanie
trwałość
beton wysokiej wytrzymałości
materiał ekologiczny
natural material
commercial material
nanosilika
compressive strength
durability
high performance concrete
eco-friendly material
Opis:: This study provides a comparative analysis of natural nanosilica (NSn), which is an extract of natural silica sand processed into nanosilica with commercial nanosilica (NSc) derived from semiconductor industrial waste, in 80 MPa high performance concrete (HPC). The percentage of using nanosilica is (3%, 5%, 10%, 15%) by weight of cement used directly and combined with 5% silica fume. Analysis was carried out through compressive strength test, durability through permeability test, rapid chloride penetration test (RCPT), and microstructure test through scanning electron microscopy (SEM). The results of the analysis show that natural nanosilica is equivalent to commercial nanosilica, in applications it is better to use silica fume incorporation. The optimum percentage of using NSn10% and (SF) 5%, while 5% NSc and 5% SF, in these proportions shows the best compressive strength and durability. It’s just that the use of natural nanosilika is 5% more than commercial nanosilika. The benefit of this research is that natural materials such as silica sand with high SiO2 content, can be processed into nanosilica as an advanced material, which can be used as an eco-friendly construction material.
Źródło:: Archives of Civil Engineering; 2023, 69, 3; 49--63
1230-2945
Pojawia się w:: Archives of Civil Engineering
Dostawca treści:: Biblioteka Nauki