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Tytuł:
Efektywność tłumienia zaburzeń doziemnych filtrów silnikowych LC w napędach z falownikami napięciowymi zasilanymi z sieci IT
Efficiency of the impairment of ground current disturbances of LC engine filters in the drives with voltage inverters supplied from an IT network
Autorzy:
Szymański, J.
Szymański, B.
Powiązania:
https://bibliotekanauki.pl/articles/187663.pdf
Data publikacji:
2011
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Technik Innowacyjnych EMAG
Tematy:
silnikowe filtry pasywne LC
passive LC motor filters
Opis:
W artykule zawarto porównanie wybranych właściwości silnikowych filtrów pasywnych LC, ograniczających prądy doziemne kabli silnikowych i silników, w napędach z napięciowymi przemiennikami częstotliwości. Przeprowadzono badania filtrów LC stosowanych w napędach zasilanych z sieci nieuziemionych typu IT. W badaniach oceniających efektywność filtracji napięcia zaburzeń wspólnych uwzględniono takie kryteria jak: napięcie względem ziemi punktu neutralnego uzwojeń stojana silnika i prąd doziemny w przewodzie ochronnym PE oraz napięcie fazowe i międzyfazowe na zaciskach silnika.
In the article basic features' comparison of different kinds of passive LC motor filters, utilized in order to reduce inverter's the differential and common voltage in the frequency converters drives, is presented. Filters' examinations were prepared for non-grounded power supply of electrical drives (IT mains) where parasitic ground capacitances of a screened motor cable have significant value. Filters were compared under following criteria: voltage of stator windings neutral point to grounded motors cover, high frequency parasitic current in PE conductor, value of motor phase-ground and phase-phase voltage. Examinations were made for unscreened and screened motor cables.
Źródło:
Mechanizacja i Automatyzacja Górnictwa; 2011, R. 49, nr 7, 7; 25-34
0208-7448
Pojawia się w:
Mechanizacja i Automatyzacja Górnictwa
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Completion of a half linearly cyclically ordered group
Autorzy:
Černák, Štefan
Powiązania:
https://bibliotekanauki.pl/articles/729059.pdf
Data publikacji:
2002
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
dedekind cut
cyclically ordered group
lc-group
half lc-group
completion of a half lc-group
Opis:
The notion of a half lc-group G is a generalization of the notion of a half linearly ordered group. A completion of G by means of Dedekind cuts in linearly ordered sets and applying Świerczkowski's representation theorem of lc-groups is constructed and studied.
Źródło:
Discussiones Mathematicae - General Algebra and Applications; 2002, 22, 1; 5-23
1509-9415
Pojawia się w:
Discussiones Mathematicae - General Algebra and Applications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Zastosowanie falowników rezonansowych w przemyśle elektromaszynowym i wydobywczym
Application of resonance inverters in the electric machine and mining industry
Autorzy:
Marek, A.
Powiązania:
https://bibliotekanauki.pl/articles/186005.pdf
Data publikacji:
2009
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Technik Innowacyjnych EMAG
Tematy:
falownik L-LC
falownik rezonansowy
inverter L-LC
resonance inverter
Opis:
Celem artykułu jest przedstawienie i omówienie najczęściej stosowanych układów zasilających nagrzewnice indukcyjne, ich właściwości oraz porównanie ich z proponowanym rozwiązaniem w postaci falownika L-LC.
The paper aims at a presentation and a discussion on the mostly used power supply systems for induction heaters, their characteristics and comparison to a suggested system in the form of an inverter L-LC.
Źródło:
Mechanizacja i Automatyzacja Górnictwa; 2009, R. 47, nr 2, 2; 17-22
0208-7448
Pojawia się w:
Mechanizacja i Automatyzacja Górnictwa
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Note on Gödel-Dummet Logic LC
Autorzy:
Robles, Gemma
Méndez, José M.
Powiązania:
https://bibliotekanauki.pl/articles/2033854.pdf
Data publikacji:
2021-07-01
Wydawca:
Uniwersytet Łódzki. Wydawnictwo Uniwersytetu Łódzkiego
Tematy:
Intermediate logics
Gödel-Dummet logic LC
Opis:
Let \(A_{0},A_{1},...,A_{n}\) be (possibly) distintict wffs, \(n\) being an odd number equal to or greater than 1. Intuitionistic Propositional Logic IPC plus the axiom \((A_{0}\rightarrow A_{1})\vee ...\vee (A_{n-1}\rightarrow A_{n})\vee (A_{n}\rightarrow A_{0})\) is equivalent to Gödel-Dummett logic LC. However, if \(n\) is an even number equal to or greater than 2, IPC plus the said axiom is a sublogic of LC.
Źródło:
Bulletin of the Section of Logic; 2021, 50, 3; 325-335
0138-0680
2449-836X
Pojawia się w:
Bulletin of the Section of Logic
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Collisional Line Shapes in the Presence of Broad-Band Squeezed Vacuum
Autorzy:
Cong, N. H.
Vinh, L. V.
Powiązania:
https://bibliotekanauki.pl/articles/2025783.pdf
Data publikacji:
2001-05
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
42.50.Lc
42.50.Ct
Opis:
In this paper we discuss the line shapes of a two-level atom in the presence of broad-band squeezed vacuum and collisional broadening. We describe the collisions and the squeezed vacuum using a stochastic model of Rabi amplitude fluctuations. From such a stochastic description the fast and the slow damping rates of the Bloch polarizations are obtained. The strong field resonance fluorescence spectrum in the presence of stochastic broad-band squeezed vacuum and collisions is derived.
Źródło:
Acta Physica Polonica A; 2001, 99, 5; 545-555
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Structural Phase Transition of Co-Ni-Si-B Amorphous Alloy
Autorzy:
Jakubczyk, E.
Powiązania:
https://bibliotekanauki.pl/articles/2027394.pdf
Data publikacji:
2001-06
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
61.20.Lc
64.70.Pf
Opis:
Structural changes of Co$\text{}_{66}$Ni$\text{}_{12}$ Si$\text{}_{9}$B$\text{}_{13}$ amorphous alloy, stimulated by isochronal and isothermal annealing, were observed by means of the methods: electrical resistivity, Hall effect and X-ray diffraction. In the amorphous matrix at the temperature 673 K phasesα-Co and (Co,Ni)$\text{}_{5}$Si$\text{}_{2}$B are created, while at the temperature 773 K the phase (Co,Ni)$\text{}_{3}$B is formed. The structural phase transitions are related to abrupt decrease in electrical and Hall resistivities at the background of systematic decrease in these parameters values during the alloy transition from the amorphous to the crystalline state.
Źródło:
Acta Physica Polonica A; 2001, 99, 6; 673-681
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Solute-Solvent Interaction in Aqueous Solutions Studied by Optical Kerr Effect
Autorzy:
Błaszczak, Z.
Farhoud, M.
Powiązania:
https://bibliotekanauki.pl/articles/1963257.pdf
Data publikacji:
1997-03
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
42.25.Lc
42.65.An
Opis:
Solute-solvent interactions were studied by a method based on laser induced optical birefringence in aqueous solutions. The paper reports results of the optical Kerr constant measurements for binary liquid mixtures of aqueous solution of methanol, ethanol, n-propanol and acetone at room temperature in a wide range of concentrations. At 50% concentration of the above mentioned alcohols, the temperature dependence of the laser induced optical birefringence was also measured in the range from 283 K to 315 K. These data together with the density and refractive index were used to calculate the optical and specific Kerr constants. Moreover, these data enabled the calculation of the anisotropic factors, optical anisotropy and orientation function of the substances studied.
Źródło:
Acta Physica Polonica A; 1997, 91, 3; 531-541
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Circularly Polarized Light-Induced Axial Anisotropy in Achiral Isotropic Media. Magnetic Dipole Interaction with Radiation
Autorzy:
Woźniak, S.
Powiązania:
https://bibliotekanauki.pl/articles/1931345.pdf
Data publikacji:
1994-06
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
42.25.Lc
42.65.An
Opis:
The analytical explanation of axial birefringence revealed earlier by the technique of field applied molecular dynamics computer simulation is given. The point group symmetries of achiral molecules admitting the effect are determined and the estimation of the anisotropy is presented. The effect may give information on off-diagonal elements of the Rosenfeld polarizability tensor of achiral molecules.
Źródło:
Acta Physica Polonica A; 1994, 85, 6; 899-905
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Quantum Noise Characteristics of Nonlinear Optical Amplifiers
Autorzy:
Boyd, R. W.
Agarwal, G. S.
Davis, W. V.
Gaeta, A. L.
Nagasako, E. M.
Kauranen, M.
Powiązania:
https://bibliotekanauki.pl/articles/1931479.pdf
Data publikacji:
1994-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
42.65.-k
42.50.Lc
Opis:
Quantum mechanical arguments show that any optical amplifier must add noise to the amplified beam of light. For the case of a high gain amplifier with a coherent (Poissonian) input, the signal-to-noise ratio of the amplified beam must be at least two times smaller than that of the incident beam. We review the theoretical basis of this prediction. We also describe the results of our experimental investigations of the noise properties of optical amplifiers that utilize the nonlinear optical response of strongly driven atomic transitions.
Źródło:
Acta Physica Polonica A; 1994, 86, 1; 117-126
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Quantum Instabilities and Decoherence Problem
Autorzy:
Kilin, S. Ya.
Horoshko, D. B.
Shatokhin, V. N.
Powiązania:
https://bibliotekanauki.pl/articles/1968521.pdf
Data publikacji:
1998-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
42.50.Lc
03.65.Bz
Opis:
A decoherence problem is discussed by means of quantum continuous measurement theory. It is shown that the conditional state of quantum system interacting with a bath preserves its initial purity. In this presentation decoherence arises as a result of averaging over the stochastic times of reduction moments ("clicks"). A method based on external phase feedback is proposed to slow down the decoherence of field superposition state in an open optical cavity. It is also shown that an atom placed inside the optical cavity plays a role of internal self-organized positive feedback between field and atom, which leads to an exponential increase in the mean dipole moment of the atom for the field initially prepared in a superposition of coherent states, i.e. to quantum instability.
Źródło:
Acta Physica Polonica A; 1998, 93, 1; 97-104
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Cantor extension of a half lineary cyclically ordered group
Autorzy:
Černák, Štefan
Powiązania:
https://bibliotekanauki.pl/articles/728774.pdf
Data publikacji:
2001
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
convergent sequence
fundamental sequence
C-complete half lc-group
Cantor extension of a half lc-group
Opis:
Convergent and fundamental sequences are studied in a half linearly cyclically ordered group G with the abelian increasing part. The main result is the construction of the Cantor extension of G.
Źródło:
Discussiones Mathematicae - General Algebra and Applications; 2001, 21, 1; 31-46
1509-9415
Pojawia się w:
Discussiones Mathematicae - General Algebra and Applications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ograniczanie wysokoczęstotliwościowych prądów doziemnych w napędach z falownikami napięciowymi zasilanymi z sieci górniczych
High frequency ground current reduction of frequency converter drives supplied from mining power system
Autorzy:
Szymański, J.
Szymański, B.
Kasztelewicz, Z.
Powiązania:
https://bibliotekanauki.pl/articles/171284.pdf
Data publikacji:
2011
Wydawca:
Poltegor-Instytut Instytut Górnictwa Odkrywkowego
Tematy:
elektroenergetyczna sieć górnicza
falownik
filtr LC
napęd silnika
mining power system
motor drive
frequency converter
LC filter
Opis:
W artykule zawarto porównanie wybranych właściwości silnikowych filtrów pasywnych LC, ograniczających wysokoczęstotliwościowe prądy doziemne płynące przez pojemności pasożytnicze kabli silnikowych i silników. Przeprowadzono badania wybranych filtrów LC stosowanych w napędach zasilanych z sieci górniczych, w układzie sieciowym typu IT. W badaniach oceniających efektywność filtracji prądów doziemnych uwzględniono takie kryteria jak: napięcie względem ziemi punktu neutralnego uzwojeń stojana silnika, prąd doziemny w przewodzie ochronnym PE oraz napięcie fazowe zasilania przemiennika częstotliwości i napięcie międzyfazowe zasilania silnika.
In the article basic features' comparison of different kinds of passive LC motor filters, utilized in order to reduce inverter's the differential and common voltage in the frequency converters drives, is presented. Filters' examinations were prepared for non-grounded power supply of electrical drives (IT mains) where parasitic ground capacitances of a screened motor cable have significant value. Filters were compared under following criteria: voltage of stator windings neutral point to grounded motors cover, high frequency parasitic current in PE conductor, value of frequency converter phase-ground and value of motor phase-phase voltage. Examinations were made for unscreened and screened motor cables.
Źródło:
Górnictwo Odkrywkowe; 2011, 52, 5; 7-14
0043-2075
Pojawia się w:
Górnictwo Odkrywkowe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Development and validation of rapid LC-MS with electrospray ionization for the quantification of pramipexole in human plasma
Autorzy:
Lavudu, P.
Rani, A. P.
Sekharan, C. B.
Powiązania:
https://bibliotekanauki.pl/articles/411617.pdf
Data publikacji:
2014
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Pramipexole
LC-MS
human plasma
bioanalytical metod
Opis:
A rapid, accurate and precise LC-MS method is described for the quantitative determination of pramipexole in human plasma matrix using ropinirole as internal standard. Pramipexole and ropinirole were extracted from plasma by liquid-liquid extraction technique. The method was validated over the concentration range of 100-2514 pg/mL. The method was found to have acceptable accuracy, precision, linearity and selectivity. The mean extraction recovery from spiked plasma samples was in the range of 79.415-87.00 %. The intra-day accuracy of the assay ranged from 98.924 to 112.236 % and intra-day precision ranged from 3.489 to 6.756 %. Inter-day accuracy and precision results for quality control samples ranged between 100.340 and 107.443% of nominal and precision is observed to be 3.970-5.714 %. The pramipexole was found to be stable after several stability studies. The proposed method yielded a quick, simple and reliable protocol for estimating pramipexole concentrations in human plasma.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2014, 18; 1-15
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mass Spectrometric Detection of New Betalains in Mammillaria Flowers
Autorzy:
Szot, Dominika
Starzak, Karolina
Skopińska, Anna
Wybraniec, Sławomir
Powiązania:
https://bibliotekanauki.pl/articles/1034229.pdf
Data publikacji:
2015
Wydawca:
Uniwersytet Jagielloński. Wydawnictwo Uniwersytetu Jagiellońskiego
Tematy:
Cactaceae
LC-MS
Mammillaria
betacyanins
natural pigments
Opis:
Betacyanins are natural, red-violet betalain pigments which can be found in plenty of plants of the Cactaceae family. The Mammillaria is the widest genus of the Cactaceae family of which fruit was examined for betacyanins contents. As a result of the investigation, a new pigment structure, mammillarinin, was identified. Heretofore, no betacyanins of Mammillaria coronata flowers has been extensively studied. In this report, the results of betacyanin analysis by LC-DAD-ESI-MS/MS in the flower extract are presented.
Źródło:
Zeszyty Naukowe Towarzystwa Doktorantów Uniwersytetu Jagiellońskiego. Nauki Ścisłe; 2015, 10; 189-196
2082-3827
2084-977X
Pojawia się w:
Zeszyty Naukowe Towarzystwa Doktorantów Uniwersytetu Jagiellońskiego. Nauki Ścisłe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Simultaneous determination of lopinavir, saquinavir and ritonavirin in human plasma using liquid chromatography – ion trap mass spectrometry
Autorzy:
Lipiński, Marcin
Bielawski, Krzysztof P.
Słomińska, Ewa M.
Smoleński, Ryszard T.
Powiązania:
https://bibliotekanauki.pl/articles/1891025.pdf
Data publikacji:
2021-12-02
Wydawca:
Gdański Uniwersytet Medyczny
Tematy:
antiviral therapy
lopinavir
saquinavir
ritonavir
LC/MS
Opis:
Background: Lopinavir, saquinavir, and ritonavir are viral protease inhibitors (PIs) developed for and widely used in the therapy of human immunodeficiency virus (HIV)-related disease. These compounds are also active in vitro against the pathogens causing tuberculosis, malaria and coronavirus infections. PIs have been regarded as a platform for the design of inhibitors targeting severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-encoded proteases. This study aimed to develop a liquid chromatography/mass spectrometry (LC/MS) procedure for accurate simultaneous determination of concentrations of these three PIs in the plasma. Methods: Samples of human plasma were protein precipitated with 0.3 M zinc sulfate in a water/methanol solution (30:70, v/v). The extracts were analyzed with reversed-phase chromatography coupled with the electrospray ionization (ESI) source of the ion trap mass detector operating in mEass spectrometry (MS) and tandem mass spectrometry (MS/MS) modes. Results: Calibration curves demonstrated good linearity from 0.01 to 10 µg/mL and acceptable reproducibilities and recoveries. Conclusions: The described procedure proves that a very basic ion-trap LC/MS system could be applied for selective, rapid, and precise determination of antiviral protease inhibitors.
Źródło:
European Journal of Translational and Clinical Medicine; 2021, 4, 2; 60-67
2657-3148
2657-3156
Pojawia się w:
European Journal of Translational and Clinical Medicine
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dissipation of methomyl residues in tomato fruits, soil and water using LC-MS/MS
Autorzy:
El-Hefny, D.
Abdallah, I.
Helmy, R.
Mahmoud, H.
Powiązania:
https://bibliotekanauki.pl/articles/2084623.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
dissipation
LC-MS/MS
methomyl
tomato
QuEChERS
Opis:
Tomato is an economically important vegetable crop which is attacked heavily by insect pests leading to reduction of yield and quality of the fruits. Field experiments were carried out to investigate the dissipation of methomyl (a common insecticide) used mainly on tomato fruits. LC-MS/MS coupled with the QuEChERS method were used for the determination of methomyl. The results showed that the recovery using matrix-matched standards ranged from 87.8 to 101.3%, with relative standard deviation of 2.5 to 7.5%. Kinetics equation, Log R = log R0 – 0.434 Kt, was used to calculate the rate of degradation in tomato, soil and water. Residue half-life calculated using kinetic rate ranged from 1.95 to 1.63 days in tomato and soil, respectively. From the results it was concluded that tomato fruits can be safely harvested for consumption after 15 days of application based on estimated preharvest interval (PHI). It is advisable to re-estimate the PHI regularly owing to data from the EU and Codex.
Źródło:
Journal of Plant Protection Research; 2019, 59, 3; 355-361
1427-4345
Pojawia się w:
Journal of Plant Protection Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
New Rapid Analysis of two Classes of Pesticides in Food Wastewater by Quechers-Liquid Chromatography/Mass Spectrometry
Autorzy:
Łozowicka, B.
Kaczyński, P.
Szabuńko, J.
Ignatowicz, K.
Warentowicz, D.
Łozowicki, J.
Powiązania:
https://bibliotekanauki.pl/articles/123585.pdf
Data publikacji:
2016
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
wastewater
azole
neonicotinoids
QuEChERS
LC-MS/MS
Opis:
The rapid analytical method was developed in response to increasing concern over the environmental impact of azoles (sterol biosynthesis inhibitors) and neonicotinoids (nicotinic acetylcholine receptor site). These chemicals are commonly used to protect fruit and vegetables crops against fungi and pests. Seven insecticides and twenty one fungicides commonly occurring in food industrial wastewater have been determined. For this purpose, active substances from two new pesticide classes were extracted and isolated by QuEChERS by addition of acetonitrile, buffering salts and chitin as a clean-up sorbent. The novelty of this procedure was one step sample preparation including extraction and removing of co-extracts in short time. Instrumental analysis was conducted by liquid chromatography coupled with mass spectrometry using multiple reaction monitoring. The limits of detection ranged from 0.002 to 0.005 μg·L-1 with satisfactory accuracy and precision The recoveries for the pesticides ranged from 81–103%, with high repeatability (n = 3, RSD ≤ 9%) and low LOQs (0.01 μg·L-1). Matrix effects calculated were less than 12% for all analyses. The method was applied to routine analysis of food industrial wastewater. Concerning the results, total pesticide levels in most cases were below 1 μg·L -1. The most significant pesticides in terms of concentration and frequency of detection were acetamiprid (0.07 μg· L-1); tebuconazole (1.2 μg· L-1) and thiacloprid (0.04 μg·L-1).
Źródło:
Journal of Ecological Engineering; 2016, 17, 3; 97-105
2299-8993
Pojawia się w:
Journal of Ecological Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Przegląd rodzajów chiralnych faz stacjonarnych oraz możliwości ich zastosowań w chromatografii cieczowej
Types of chiral stationary phases and its applications to liquid chromatography (LC) – a mini review
Autorzy:
Śliwka-Kaszyńska, M.
Momotko, M.
Szarmańska, J.
Boczkaj, G.
Kamiński, M.
Powiązania:
https://bibliotekanauki.pl/articles/92336.pdf
Data publikacji:
2015
Wydawca:
Uniwersytet Przyrodniczo-Humanistyczny w Siedlcach
Tematy:
chiralne rozdzielenie
chiralne fazy stacjonarne (CSP)
chromatografia cieczowa(LC)
chiral separation
Chiral Stationary Phases (CSP)
Liquid Chromatography (LC)
Opis:
Chromatograficzne rozdzielanie związków optycznie czynnych ma ogromne znaczenie nie tylko w przemyśle farmaceutycznym, ale i agrochemicznym, a także w badaniach naukowych różnego rodzaju. W niniejszym opracowaniu scharakteryzowano komercyjnie dostępne chiralne fazy stacjonarne na bazie, cyklodekstryn, polisacharydów, makrocyklicznych antybiotyków, eterów koronowych, a także fazy proteinowe, ligandowymienne, jonowymienne oraz fazy typu Pirkle’a. Omówiono podstawowe właściwości fizyczne i chemiczne w/w faz stacjonarnych, przedstawiono przykładowe ich struktury, mechanizmy chiralnego rozpoznania oraz podstawowe zastosowania. Opisano również warunki chromatograficznego rozdzielania chiralnego dla wybranych farmaceutyków i pestycydów.
Importance of chromatographic enantioseparations in the pharmaceutical and agrochemical industries is still increasing. In this paper the chiral stationary phases, including cyclodextrins, polysaccharides, macrocyclic antibiotics, crown ethers, proteins, ligand-exchange, Pirkle-type and ion exchange phases is discussed. For all types of chiral stationary phases, the basic physical and chemical properties are discussed, as well as the structure and the possible chiral recognition mechanisms. The basic applications of this phases are also described. Chromatographic conditions for chiral separation of selected active pharmaceutical ingredients and pesticides are reviewed.
Źródło:
Camera Separatoria; 2015, 7, 2; 99-128
2083-6392
2299-6265
Pojawia się w:
Camera Separatoria
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Cytotoxic Test of Octopus cyanea Ink Extract
Autorzy:
Kalor, John Dominggus
Simaremare, Eva Susanty
Futwembun, Allowisya
Wabiser, Gloria
Gunawan, Elsye
Yabansabra, Yuliana Rut
Powiązania:
https://bibliotekanauki.pl/articles/125432.pdf
Data publikacji:
2019
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
toxicity
Octopus cyanea
Artemia salina leach
LC50
Opis:
Marine biodiversity of Papua is very high, but unfortunately research and utilization in medicine are limited. Many species of flora and fauna are used in ethopharmacology as drugs but without scientific explanation, e.g. octopus (Octopus cyanea), found in the Northern Papua Sea. The aim of this research was to test the toxicity of the ethanol octopus ink. The toxicity was tested with the Brine Shrimp Lethality Test (BSLT) method. The samples were collected from the sea of Biak island in West Papua, extracted with ethanol, ethyl acetate, and dichloromethane then tested the toxicity for Artemia salina leach larvae. The toxicity test involved concentrations of 1000, 750, 500, 250, 100, 75, 50, and 25 ppm. The result showed that ethanol extract of octopus ink has LC50 of 290 ppm, ethyl acetate extract has LC50 of 947 ppm, whereas dicholoromethane extract – 2190 ppm.
Źródło:
Journal of Ecological Engineering; 2019, 20, 8; 144-152
2299-8993
Pojawia się w:
Journal of Ecological Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Stabilisation of LC ladder network with the help of delayed output feedback
Autorzy:
Baranowski, J.
Mitkowski, W.
Powiązania:
https://bibliotekanauki.pl/articles/206281.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Instytut Badań Systemowych PAN
Tematy:
stabilisation
delay differential equation
LC ladder network
D-partitions
Opis:
The paper presents a method of stabilisation of an LC ladder network with a delayed output feedback. A discussion of certain properties of tridiagonal matrices and formulation of the considered system in state space equations is included. Formal stability of the arising infinite dimensional system is described and stability conditions are formulated based on properties of characteristic quasipolynomial. The method of D-partitions is used to determine the stability regions in the controller parameter space. Paper includes examples for ladders of dimensions 1, 2 and 3 and a comparison with Padé approximation.
Źródło:
Control and Cybernetics; 2012, 41, 1; 13-34
0324-8569
Pojawia się w:
Control and Cybernetics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Application of Scattered Light in the Metrology of Planar Waveguides
Autorzy:
Gut, K.
Powiązania:
https://bibliotekanauki.pl/articles/1417959.pdf
Data publikacji:
2012-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
42.25.Ja
42.25.Lc
42.25.Fx
Opis:
The paper presents a measuring stand which permits to determine the attenuation and modal birefringence of planar waveguide structures. The light is introduced into the waveguide through a prismatic coupler. This permits to determine attenuations of the subsequent modes. Mounting the polarizer in front of the lens of the camera it becomes possible to determine on the same test stand the modal birefringence of orthogonal pair of modes of the same order.
Źródło:
Acta Physica Polonica A; 2012, 122, 5; 818-820
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Chaos via Period-Doubling Oscillations in an Exciton-Carrier-Photon System Driven by Optical Pumping
Autorzy:
Nguyen, Ba An
Powiązania:
https://bibliotekanauki.pl/articles/1930622.pdf
Data publikacji:
1994-03
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
42.65.-k
71.35.+z
42.50.Lc
Opis:
A detailed stability analysis is performed for a highly excited semiconductor modelled as an exciton-electron-hole-photon system driven externally by optical pumping. Chaotic self-pulsations are shown to occur on both the upper and lower branches of the bistable steady state curve of the system via a sequence of period-doubling oscillation process. Such a route to chaos is well known in laser physics and in other nonlinear systems but not in highly excited semiconductors yet.
Źródło:
Acta Physica Polonica A; 1994, 85, 3; 541-552
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Magneto-Optical Characteristics of Human Serum
Autorzy:
Surma, M.
Bućko, J.
Bąk, G.
Ciszek, M.
Powiązania:
https://bibliotekanauki.pl/articles/2014394.pdf
Data publikacji:
2000-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
42.25.Lc
78.20.Ek
78.20.Ls
Opis:
A study of magneto-optical circular birefringence of human serum from healthy subjects and cancer patients was performed. Significant differences in the magnetic field induced change of the natural optical activity of serum from healthy blood donors and neoplasmic patients were noted. The natural optical activity of blood is positive, irrespective of the donor health status, whereas the magnetic field induced (B > 10T) change in the natural optical activity of the serum from cancer patients is negative while that from healthy donors is positive. The value and sign of the characteristic magneto-optical marker of human serum was discovered in a study of the influence of very high magnetic fields on chiral media and interpreted on the basis of the recent developments in the theory of magnetic field induced optical circular birefringence in the media revealing natural optical activity. The blood serum is a chiral medium.
Źródło:
Acta Physica Polonica A; 2000, 98, 5; 533-542
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Atomic Motion in Amorphous Solids
Autorzy:
Schober, H.
Powiązania:
https://bibliotekanauki.pl/articles/2035455.pdf
Data publikacji:
2002-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
61.43.Fs
61.20.Lc
81.05.Kf
Opis:
Glasses and amorphous materials show, coexisting with the sound waves, a variety of low energy excitations: tunneling, quasi-localized vibrations and relaxations. The latter two are observed well into the liquid state. Using molecular dynamics both were shown to be centred on more than ten atoms or molecular units, which form chain-like structures. With increasing frequency the interaction of the quasi-localized modes with the sound waves and with each other increases, they delocalize. However, even at the so-called boson peak frequency, where the sound waves become overdamped due to the interaction, the vibrations can be decomposed into local and extended modes. Closely correlated with the local vibrations are the local relaxations, which can be envisaged as collective jumps of groups of atoms. With rising temperature both the total jump length and the number of atoms participating increases. In the melt when single jumps are no longer resolved one still observes a collective motion of chains of atoms.
Źródło:
Acta Physica Polonica A; 2002, 102, 1; 83-93
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Phytochemical composition and antibacterial activity of ethanolic extract from trunk of Rothmannia wittii (Craib) Bremek. (Rubiaceae) newly found in Vietnam
Autorzy:
Van, H.T.
Nguyen, T.T.
Ton, H.T.T.
Dinh, K.T.T.
Le, V.S.
Pham, T.V.
Tran, G.B.
Powiązania:
https://bibliotekanauki.pl/articles/2096309.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Rothmannia wittii
extract
phytochemical composition
antibacterial activity
LC-MS
Opis:
Rothmannia wittii, which is found in Binh Chau-Phuoc Buu Nature Reserve, Bung Rieng ward, Xuyen Moc District, Ba Ria-Vung Tau Province, Vietnam, is a rare species of Rubiaceae family. The present study aimed to determine the phytochemical composition and antimicrobial activity of the ethanolic extract of the R. wittii trunk. A total of 10 compounds were identified by liquid chromatography-mass spectrophotometry (LC-MS), including 1) benzene, 1-(1,5-dimethyl-4- hexenyl)-4-methyl, 2) diphenylsulfone, 3) 6β-hydroxy-10-O-acetylgenipin, 4) cinnamyl-cinnamate, 5) genipin, 6) megastigmatrienone, 7) ethyl p-methoxy-trans-cinnamate, 8) rothalazepane, 9) 1,3,6-trimethylpyrano[2,3-d ]imidazole-2,5(1H,3H)-dione, and 10) shanzhiol. The extract also exhibited an antibacterial activity against six bacterial strains: Bacillus cereus, Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, Salmonella typhimurium and Salmonella enteritidis, as determined via disk diffusion agar method.
Źródło:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology; 2020, 101, 4; 301-307
0860-7796
Pojawia się w:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Betaxanthin Profiling in Beta vulgaris Leaves and Gymnocalycium mihanovichii Grafted Cacti: A Comprehensive Study
Autorzy:
Spórna-Kucab, Aneta
Tekieli, Anna
Knapek, Magdalena
Zużałek, Marta
Wybraniec, Sławomir
Powiązania:
https://bibliotekanauki.pl/articles/24024625.pdf
Data publikacji:
2023-12-05
Wydawca:
Instytut Rozrodu Zwierząt i Badań Żywności Polskiej Akademii Nauk w Olsztynie
Tematy:
beet
betalains
colorants
grafted cactus
LC-MS
secondary metabolites
Opis:
This study was focused on the identification and quantification of betaxanthins using high-performance liquid chromatography with a diode array detector coupled to electrospray ionisation mass spectrometry (HPLC-DAD-ESI-MS) in leaves of various cultivars of Beta vulgaris (beet) and Gymnocalycium mihanovichii grafted cacti. In G. mihanovichii grafted cacti, four betaxanthins, namely histidine-Bx, histamine-Bx, serine-Bx, and proline-Bx, were tentatively identified in the yellow, orange, pink, and red varieties, with contents ranging from 0.09 to 1.55 mg/kg fresh weight (FW). Betaxanthins were not detected in the green cactus. Histidine-Bx was the prevailing betaxanthin compound in the majority of cultivars. Fifteen betaxanthins were successfully identified in the leaves of five B. vulgaris cultivars (cv.): Snow Ball, Boldor, Cylindra, Rhubarb, and Round Dark Red. Leaves of yellow beet (cv. Boldor) had the highest total betaxanthin content (20.4 mg/kg FW), while white beet (cv. Snow Ball) had the lowest one (3.43 mg/kg FW). The leaves of red cultivars had comparable betaxanthin contents, ranging from 13.4 to 18.8 mg/kg FW, similary to the yellow cultivar, indicating their potential as valuable sources of betaxanthins. There was no single dominant betaxanthin in B. vulgaris leaves. The leaves of B. vulgaris were found to be a richer source of betaxanthin than the grafted cactus G. mihanovichii, which opens up new prospects for research into the potential utilization of these compounds in the industry.
Źródło:
Polish Journal of Food and Nutrition Sciences; 2023, 73, 4; 375-384
1230-0322
2083-6007
Pojawia się w:
Polish Journal of Food and Nutrition Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Acrylamide content in cigarette mainstream smoke and estimation of exposure to acrylamide from tobacco smoke in Poland
Autorzy:
Mojska, Hanna
Gielecińska, Iwona
Cendrowski, Andrzej
Powiązania:
https://bibliotekanauki.pl/articles/989240.pdf
Data publikacji:
2016
Wydawca:
Instytut Medycyny Wsi
Tematy:
acrylamide
cigarette mainstream smoke
lc-ms/ms
exposure assessment
Opis:
Introduction and objective. Acrylamide is a “probably human carcinogen” monomer that can form in heated starchy food as a result of a reaction between asparagine and reducing sugars via Maillard reaction. The main source of acrylamide in human diet are potato products, cereal products and coffee. Tobacco smoke may be another significant source of exposure to acrylamide. The aim of our study was to determine acrylamide content in cigarettes available on the Polish market and to estimate the exposure to acrylamide originating from tobacco smoke in smokers in Poland. Materials and methods. The material was cigarettes of the top five brands bought in Poland and tobacco from non-smoked cigarettes. Acrylamide content in cigarettes mainstream smoke was determined by LC-MS/MS. Exposure assessment was carried out using analytical data of acrylamide content in cigarettes and the mean quantity of cigarettes smoked daily by smokers in Poland, assuming body weight at 70 kg. Results. The mean content of acrylamide was 679.3 ng/cigarette (range: 455.0 – 822.5 ng/cigarette). The content of acrylamide was evidenced to correlate positively with total particulate matter (TPM) content in cigarettes. The estimated average exposure to acrylamide from tobacco smoke in adult smokers in Poland is 0.17 μg/kg b.w./day. Conclusions. Our results demonstrate that tobacco smoke is a significant source of acrylamide and total exposure to acrylamide in the population of smokers, on average, is higher by more than 50% in comparison with non-smokers. Our estimation of exposure to acrylamide from tobacco smoke is the first estimation taking into account the actual determined acrylamide content in the cigarettes available on the market.
Źródło:
Annals of Agricultural and Environmental Medicine; 2016, 23, 3
1232-1966
Pojawia się w:
Annals of Agricultural and Environmental Medicine
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Investigation of Shot Noise in Avalanche Photodiodes
Autorzy:
Kocak, F.
Kilic, A.
Tapan, I.
Powiązania:
https://bibliotekanauki.pl/articles/1398762.pdf
Data publikacji:
2016-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
42.50.Lc
29.40.Wk
02.70.Uu
Opis:
PbWO₄ crystal-Hamamatsu S8148 avalanche photodiode (APD) assembly has been used in the barrel section of the CMS electromagnetic calorimeter. The shot noise of the photodiode is one of the important parameters for the energy resolution of the crystal-APD system. The major source of this noise is the statistical variations in the rate at which primary charge carriers are generated and recombine. Thus, the shot noise varies with position of the primary charge carriers generated in photodiode. In this work, the shot noise properties of the Hamamatsu S8148 APD structure and zinc sulfide-silicon (ZnS-Si) isotype heterojunction APD structure have been compared for the PbWO₄ photons. Calculations were made with a Single Particle Monte Carlo simulation technique.
Źródło:
Acta Physica Polonica A; 2016, 129, 4; 721-723
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Methods of Determining the Beat Length of Planar Waveguides
Autorzy:
Gut, K.
Powiązania:
https://bibliotekanauki.pl/articles/1399348.pdf
Data publikacji:
2013-09
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
42.25.Ja
42.25.Lc
42.25.Fx
Opis:
The paper presents two methods of determining the planar waveguide birefringence and the measuring stands, which are used to determine the beat length of planar waveguide structures. The light is introduced into the waveguide through a prism coupler. The first method applies measurements of scattered light. The second method uses an immersion coupler. The most fundamental property of an immersion coupler is the possibility to change fluently the propagation length while immersing the waveguide.
Źródło:
Acta Physica Polonica A; 2013, 124, 3; 425-427
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Reduction of Selected Betacyanins
Autorzy:
SZOT, DOMINIKA
STARZAK, KAROLINA
SKOPIŃSKA, ANNA
WYBRANIEC, SŁAWOMIR
Powiązania:
https://bibliotekanauki.pl/articles/1034140.pdf
Data publikacji:
2014
Wydawca:
Uniwersytet Jagielloński. Wydawnictwo Uniwersytetu Jagiellońskiego
Tematy:
1
7-diazaheptamethin
LC-MS
betanin
chromophore
decarboxy-betacyanins
reduction
Opis:
Betacyanins are conjugates of betalamic acid and glycosylated cyclo-DOPA which bring about the creation of a specific chromophoric system, the 1,7-dia- zaheptamethin chain. Betanin, a betacyanin pigment from red beet (Beta vulga- ris L.), as well as its decarboxylated derivatives were subjected to reduction with the use of NaBH4. The pigment structures contain a vinyl linker which is postu- lated to be protonated during reaction with NaBH4. In this study, 17-decarboxy- betanin and 2,17-bidecarboxy-betanin were obtained from betanin, which had been previously isolated from red beet root (Beta vulgaris L.). Purified pigments were tested in the presence of the reduction reagent while looking for the prod- ucts of the reaction identified by LC-MS.
Źródło:
Zeszyty Naukowe Towarzystwa Doktorantów Uniwersytetu Jagiellońskiego. Nauki Ścisłe; 2014, 8; 265-273
2082-3827
2084-977X
Pojawia się w:
Zeszyty Naukowe Towarzystwa Doktorantów Uniwersytetu Jagiellońskiego. Nauki Ścisłe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Thermal analysis of CMOS voltage-controlled oscillators
Analizy termiczne generatorów przestrajanych napięciem
Autorzy:
Frankiewicz, M.
Kos, A.
Powiązania:
https://bibliotekanauki.pl/articles/408120.pdf
Data publikacji:
2012
Wydawca:
Politechnika Lubelska. Wydawnictwo Politechniki Lubelskiej
Tematy:
VCO
układy rezonansowe
generatory pierścieniowe
CMOS
temperatura
LC
RO
temperature
Opis:
The paper presents impact of chip temperature on frequency generated by Voltage-Controlled Oscillators. Three different CMOS structures have been tested. Resonant cross-coupled oscillator was designed and fabricated in AMS 0.35 žm (3.3 V) technology and has at ambient temperature the frequency range from 2.2 to 2.5 MHz. Two different ring oscillators were designed in UMC 0.18 žm (1.8 V) technology and have at ambient temperature the frequency range respectively from 0.6 to 2.8 GHz and from 0.4 to 1.9 GHz. All circuits were designed using full-custom technique. Influence of temperature to tuning range and power consumption has been investigated.
Artykuł przedstawia wpływ temperatury na działanie generatorów przestrajanych napięciem VCO. Przebadane zostały trzy różne struktury układów CMOS. Generator rezonansowy został zaprojektowany i sfabrykowany w technologii AMS 0,35 žm (3,3 V) i w temperaturze pokojowej generuje częstotliwości z zakresu ad 2,2 do 2,5 MHz. Dwa odmienne generatory pierścieniowe zostały zaprojektowane w technologii UMC 0,18 žm (1,8 V) i generują częstotliwości z zakresu odpowiednio od 0,6 do 2,8 GHz oraz od 0,4 do 1,9 GHz. Wszystkie układy zostały zaprojektowane techniką full-custom. Przetestowane zostało oddziaływanie termiczne na zakres przestrajania oraz pobór mocy generatorów.
Źródło:
Informatyka, Automatyka, Pomiary w Gospodarce i Ochronie Środowiska; 2012, 4b; 3-6
2083-0157
2391-6761
Pojawia się w:
Informatyka, Automatyka, Pomiary w Gospodarce i Ochronie Środowiska
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Predictive current control of three-phase matrix converter with GaN HEMT bidirectional switches
Autorzy:
Nowaszewski, K.
Sikorski, A.
Powiązania:
https://bibliotekanauki.pl/articles/202007.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
predictive control
matrix converter
GaN HEMT
LC filter
bidirectional switch
Opis:
This paper presents an analysis and simulation studies of three-phase matrix converter with GaN HEMT bidirectional switches with predictive control of grid currents and converter output currents. Two methods of grid currents shaping are described and compared. The first method is based on calculations of instantaneous grid reactive power and the second one uses the active power of the load. The analyzed converter works with the resistive-inductive load, and from the grid side the LC filter with damping resistor has been used.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2020, 68, 5; 1077-1085
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Bioinformatic insight into Portulaca oleracea L. (Purslane) of Bulgarian and Greek origin
Autorzy:
Balabanova, V.
Hristov, I.
Zheleva-Dimitrova, D.
Sugareva, P.
Lozanov, V.
Gevrenova, R.
Powiązania:
https://bibliotekanauki.pl/articles/2117810.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
Portulaca oleracea
LC–HRAMS
secondary metabolites
descriptive analysis
multivariate statistics
Opis:
Portulaca oleracea L. (Portulacaceae) is used as functional food and its nutritional and therapeutic properties are related to the high levels of organic and fatty acids, polyphenols, polysaccharides and cyclo-dopa amides. This study presents a strategy based on liquid chromatography – high resolution accurate mass spectrometry method (LC – HRAMS) and bioinformatic methods to analyze 33 purslane accessions originating from 11 floristic regions in Bulgaria together with 5 accessions of Greek provenance. Extracts were obtained by microwave extraction. Based on the LC-MS metabolic “fingerprints” of assayed samples, a purslane metabolic database was developed. LC-MS data were proceeded with Software application Compound Discover 2.0 (Thermo Fischer Sci., USA). Principal Component Analysis (PCA) combined with both descriptive and differential analyses were used to find marker metabolites to distinguish different geographical regions. The differential analysis of the Bulgarian and Greek samples allowed the identification of 50 marker metabolites. Based on accurate masses, retention times, fragmentation patterns in MS/MS, comparison with commercial standards and literature data, these secondary metabolites were identified after detailed analysis of Volcano-plots. For the first time, 29 compounds are reported. The identified compounds were used to perform a study of the biosynthetic pathways of purslane secondary metabolites using Kyoto Encyclopedia of Genes and Genomes (KEGG) software platform. The statistical treatments identified marker compounds that can be used to distinguish the origin of accession set. Combining LC-MS data with multivariate statistical analysis was shown to be effective in studying the purslane metabolites, allowing for integration of chemistry with geographic origin.
Źródło:
Acta Biologica Cracoviensia. Series Botanica; 2020, 62, 1; 7-21
0001-5296
Pojawia się w:
Acta Biologica Cracoviensia. Series Botanica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Izolacja i identyfikacja naturalnych substancji barwiących obecnych w próbkach farb artystycznych i tkaninach pochodzenia historycznego
Isolation and identification of natural dyestuffs present in artistic paints and textiles of historical origin
Autorzy:
Otłowska, O.
Śliwka-Kaszyńska, M.
Kołodziejczyk, A.
Powiązania:
https://bibliotekanauki.pl/articles/172392.pdf
Data publikacji:
2016
Wydawca:
Polskie Towarzystwo Chemiczne
Tematy:
barwniki
naturalne barwniki organiczne
analiza LC-DAD-MS
ekstrakcja
historyczne farby artystyczne
natural organic dyes
analysis LC-DAD-MS
extraction
historical artistic paints
Opis:
Natural organic dyes are group of substances that belong to various types of chemical compounds. The most commonly used in paintings and dyeing textiles were naturally occurring dyestuffs from group of anthraquinones, flavones and indigoid dyes. Identification of coloring substances present in historical artistic paints provides relevant information for a wide range of specialists dealing with works of art and in the field of conservation science. This research presents a review of analytical techniques (mainly chromatographic and spectroscopic) used for identification of dyes. It also describes the methods of colorants isolation from historical artistic paints and textiles. Furthermore, the article presents a brief characteristics of fragmentation reactions of selected groups of dyestuffs, which is useful in their identification.
Źródło:
Wiadomości Chemiczne; 2016, 70, 3-4; 163-187
0043-5104
2300-0295
Pojawia się w:
Wiadomości Chemiczne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A WebGIS framework for disseminating processed remotely sensed on land cover transformations
Autorzy:
Caradonna, G.
Novelli, A.
Tarantino, E.
Cefalo, R.
Fratino, U.
Powiązania:
https://bibliotekanauki.pl/articles/106878.pdf
Data publikacji:
2016
Wydawca:
Politechnika Warszawska. Wydział Geodezji i Kartografii
Tematy:
WebGIS
satellite data
LU/LC
vegetation analysis
dane satelitarne
analiza roślinności
Opis:
Mediterranean regions have experienced significant soil degradation over the past decades. In this context, careful land observation using satellite data is crucial for understanding the long-term usage patterns of natural resources and facilitating their sustainable management to monitor and evaluate the potential degradation. Given the environmental and political interest on this problem, there is urgent need for a centralized repository and mechanism to share geospatial data, information and maps of land change. Geospatial data collecting is one of the most important task for many users because there are significant barriers in accessing and using data. This limit could be overcome by implementing a WebGIS through a combination of existing free and open source software for geographic information systems (FOSS4G). In this paper we preliminary discuss methods for collecting raster data in a geodatabase by processing open multi-temporal and multi-scale satellite data aimed at retrieving indicators for land degradation phenomenon (i.e. land cover/land use analysis, vegetation indices, trend analysis, etc.). Then we describe a methodology for designing a WebGIS framework in order to disseminate information through maps for territory monitoring. Basic WebGIS functions were extended with the help of POSTGIS database and OpenLayers libraries. Geoserver was customized to set up and enhance the website functions developing various advanced queries using PostgreSQL and innovative tools to carry out efficiently multi-layer overlay analysis. The end-product is a simple system that provides the opportunity not only to consult interactively but also download processed remote sensing data.
Źródło:
Reports on Geodesy and Geoinformatics; 2016, 100; 27-38
2391-8365
2391-8152
Pojawia się w:
Reports on Geodesy and Geoinformatics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dielectric relaxation modes in antiferroelectric liquid crystal mixture
Procesy relaksacji dielektrycznych w antyferroelektrycznej mieszaninie ciekłokrystalicznej
Autorzy:
Wojciechowski, M.
Powiązania:
https://bibliotekanauki.pl/articles/296684.pdf
Data publikacji:
2007
Wydawca:
Politechnika Łódzka. Wydawnictwo Politechniki Łódzkiej
Tematy:
antyferroelektryczne związki ciekłokrystaliczne
relaksacja dielektryczna
soft mode
antiferroelectric LC
dielectric relaxations
Opis:
Mixture of liquid crystals, with induced antiferroelectric phase has been studied by means of dielectric spectroscopy. The dielectric measurements were carried out in a cell with gold electrodes at planar orientation. The characteristic of dielectric relaxation modes in all phases existing in the mixture are presented. The results are compared with the results obtained for the same mixture in the cell with ITO electrodes.
Spektroskopia dielektryczna została użyta do badań ciekłokrystalicznej mieszaniny z indukowaną fazą antyferroelektryczną (związki ciekłokrystaliczne, z których sporządzono mieszaninę nie posiadają samodzielnie fazy antyferroelektrycznej). W pracy przedstawiono dielektryczne charakterystyki poszczególnych faz oraz interpretację zarejestrowanych procesów relaksacyjnych otrzymanych w komórce o złotych elektrodach. Otrzymane wyniki porównano z wynikami otrzymanymi wcześniej w komórce z elektrodami ITO. Zdecydowane różnice w widmie dielektrycznym zaobserwowano w subfazie SmC*x co oznacza, że interpretacja tej subfazy jest jeszcze sprawą otwartą.
Źródło:
Scientific Bulletin. Physics / Technical University of Łódź; 2007, 28; 103-111
1505-1013
2449-982X
Pojawia się w:
Scientific Bulletin. Physics / Technical University of Łódź
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of the Addition of Apple Pomace and Erythritol on the Antioxidant Capacity and Antidiabetic Properties of Shortbread Cookies
Autorzy:
Raczkowska, Ewa
Wojdyło, Aneta
Nowicka, Paulina
Powiązania:
https://bibliotekanauki.pl/articles/31341114.pdf
Data publikacji:
2024-05-17
Wydawca:
Instytut Rozrodu Zwierząt i Badań Żywności Polskiej Akademii Nauk w Olsztynie
Tematy:
apple pomace
erythritol
shortbread cookies
LC-MS
antidiabetic activity
antioxidant activity
Opis:
Apple processing into juice generates vast amounts of a by-product, namely fruit pomace, which poses a serious problem for the processing industry. At the same time, fruit pomace features a high health potential. The aim of the present study was to develop recipes of 8 variants of cookies with wheat flour substituted by apple pomace (0, 10, 30 and 50% of flour weight), sweetened with sucrose and erythritol. The cookies were analyzed for their nutritional value; antioxidant capacity (ABTS•+ scavenging activity and oxygen radical absorption capacity – ORAC); the ability to inhibit α-amylase, α-glucosidase and pancreatic lipase; and consumer acceptability. In total, 13 phenolic compounds were identified in the cookies with pomace. Cookies with 50% addition of apple pomace had an approximately 8-fold higher content of dietary fibre than traditional products (without the apple pomace) and simultaneously reduced energy value (by 32.6 and 40.5 kcal/100 g of cookies sweetened with sucrose and erythritol, respectively). The antioxidant capacity of cookies was 0.032–0.316 mmol TE/100 g in the ABTS assay and 1.153–2.070 mmol TE/100 g when ORAC was determined. The IC50 enabling α-amylase and α-glucosidase inhibition ranged from 138.1 to 221.8 mg/mL and from 976.4 to 1374.9 mg/mL, respectively. The anti-lipase activity of cookies with the addition of 50% apple pomace and erythritol was the highest (IC50 of 7.3 mg/mL). Both antioxidant capacity and antidiabetic potential increased significantly with the increasing proportion of pomace in cookies. Replacing sucrose with erythritol favorably influenced the consumer assessment. The study results show that the proposed products can be a perfect alternative to traditional sweet snack products, especially for consumers with diet-related diseases. The feasibility of using waste raw materials, which are a challenge to the food industry, has been proven as well.
Źródło:
Polish Journal of Food and Nutrition Sciences; 2024, 74, 2; 147-161
1230-0322
2083-6007
Pojawia się w:
Polish Journal of Food and Nutrition Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Chromatographic fractionation of betacyanins from flowers of Gomphrena globosa
Autorzy:
Szot, D.
Starzak, K.
Skopińska, A.
Wybraniec, S.
Powiązania:
https://bibliotekanauki.pl/articles/115427.pdf
Data publikacji:
2015
Wydawca:
Fundacja na Rzecz Młodych Naukowców
Tematy:
betacyanins
Gomphrena globosa
plant pigments
LC-MS
betacyjaniny
Gomfrena kulista
barwniki roślinne
Opis:
In this study, a chromatographic fractionation of betacyanin pigments from extract of purple Gomphrena globosa petals was performed by preparative high performance liquid chromatography (prep-HPLC). The particular betacyanins in each collected fractions were tentatively identified by chromatography with optical amd mass spetrometric detection (LC-DAD-ESI-MS). Betacyanins are natural pigments, which are confirmed to have an antioxidant activity. It was reported that betacyanins can prevent civilization diseases, because of an ability of free radicals scavenging. Betacyanins are present in tissue of plants from Amaranthaceae family, e.g. in petals of Gomphrena globosa. Preparative separation of these particular pigments is difficult, because they are structurally very similar to each other and tend to coelute. However, in this study, fractions, containing a dominant amount of the principal pigments of Gomphrena globosa inflorescences, were obtained successfully. In the first fractions, two isomeric pigments assigned to gomphrenin I and isogomphrenin I were detected. The fractions of significant amounts of gomphrenin III and isogomphrenin III were obtained separately with sufficient purity. The presence of other, minor gomphrenin-type betacyanins were also confirmed as: gomphrenin II, cis-isomer of gomphrenin II and sinapoyl-gomphrenin I as well as their 15S-diastereomers. Moreover, in other fractions, various unknown pigments were detected.
Źródło:
Challenges of Modern Technology; 2015, 6, 2; 19-23
2082-2863
2353-4419
Pojawia się w:
Challenges of Modern Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Investigation of the Vibroacoustic Climate Inside the Buses MAN SG242 Used in Public Transport Systems
Autorzy:
Damijan, Z.
Powiązania:
https://bibliotekanauki.pl/articles/1537389.pdf
Data publikacji:
2010-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
89.40.-a
07.10.-h
43.40.Lc
07.64.+z
Opis:
A driver of a municipal transport bus is more liable to vibration-acoustic stimuli connected with the movement of the vehicle than a passenger. In literature on the subject noise and vibration exposures are categorised into passive (whereby passengers are exposed) and active (driver's or machine operator's exposure). Despite new technological solutions and attempts to improve the working conditions during the operation of vehicles, city bus drivers are still exposed to negative impacts of noise and vibrations, causing stress, increased fatigue and lead to numerous diseases. It is required, therefore, that the working conditions for drivers should be monitored on a regular basis. In order that they work safely, their working conditions should be as comfortable as possible, in terms of physical and psychical conditions and free from any nuisance. Therefore it seems merited to investigate the acoustic climate (i.e. acoustic phenomena caused by the sources of noise of vibrations in the function of time and space) and the working conditions during the operation of MAN SG242 vehicles, widely used in public transport systems. The following conclusions can be formulated (based on the conducted tests): the highest effective weighted values of vibration acceleration a_w, eq (0.823 m/$s^{2}$) (exceedance of the legitimate value) were noted in the passengers' compartment in the middles of the vehicle, the lowest- in the driver's cabin (0.411 m/$s^{2}$). In the driver's cabin, the peak noise level $L_C$ peak = 138.7 dB was exceeded; as the 1/3 octave analyses show, in the driver's cabin dominates low-frequency noise with the frequency from 10 to 25 Hz and the acoustic pressure level of about 90 dB (G). The research has been conducted within the framework of the author's research no 10.10.130.140 and the statuary ones no 11.11.130.119.
Źródło:
Acta Physica Polonica A; 2010, 118, 1; 27-30
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Investigation of the Vibroacoustic Climate Inside the Buses Solaris Urbino 12 Used in Public Transport Systems
Autorzy:
Damijan, Z.
Iwański, D.
Dahlke, G.
Powiązania:
https://bibliotekanauki.pl/articles/1490375.pdf
Data publikacji:
2012-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
89.40.-a
07.10.-h
43.40.Lc
07.64.+z
Opis:
Despite new technological solutions and attempts to improve the working conditions during the operation of vehicles, city bus drivers are still exposed to negative impacts of noise and vibrations, causing stress, increased fatigue and lead to numerous diseases. Therefore it seems merited to investigate the acoustic climate (i.e. acoustic phenomena caused by the sources of noise of vibrations in the function of time and space) and the working conditions during the operation of Solaris Urbino 12 vehicles, widely used in public transport systems. The main aim of the research was to show the influence of the 5 day, 8 h working week on selected psycho-physiological parameters on a driver's organism. It was assumed that the main aggravating factor of the driver's organism are vibroacoustics conditions of a work place. The results of this research will be presented in due course. This work presents the research on vibroacoustic climate in one of many city buses used - Solaris Urbino 12. Investigation of the vibroacoustic climate is the branch of environmental biophysics. The measurements, tests and analysis are genuine because they were carried out under real conditions, with passengers, in the long stretches of time and in the entire route of the vehicle. Presented results are very rarely reported in the literature.
Źródło:
Acta Physica Polonica A; 2012, 121, 1A; A-032-A-037
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Propagation of Double Resonance and Dark Area
Autorzy:
Eberly, J. H.
Kozlov, V. V.
Powiązania:
https://bibliotekanauki.pl/articles/2030482.pdf
Data publikacji:
2002-03
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
42.50.-p
42.50.Dv
42.50.Lc
42.50.Gy
Opis:
We report new results in propagation of two coherently coupled optical pulses in an inhomogeneously broadened three-level lambda medium.
Źródło:
Acta Physica Polonica A; 2002, 101, 3; 459-462
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Control of Open Quantum Systems
Autorzy:
Japha, Y.
Kofman, A. G.
Kurizki, G.
Powiązania:
https://bibliotekanauki.pl/articles/1968526.pdf
Data publikacji:
1998-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
42.50.Lc
03.65.Bz
03.75.Be
42.50.-p
Opis:
Spontaneous decay of excited cold atoms into a cavity can drastically affect their translational dynamics, namely, atomic reflection, transmission and localization at the interface. We show that the quantum Zeno effect on excitation decay of an atom is observable in open cavities and waveguides, using a sequence of evolution-interrupting pulses on a nanosecond scale.
Źródło:
Acta Physica Polonica A; 1998, 93, 1; 135-145
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Entanglement in Open Quantum Systems
Autorzy:
Buchleitner, A.
Carvalho, A. R. R.
Mintert, F.
Powiązania:
https://bibliotekanauki.pl/articles/2047819.pdf
Data publikacji:
2007-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
03.67.Mn
03.65.Ud
03.65.Yz
42.50.Lc
Opis:
We give a compact review of some of our recent results on the quantification, the measurement, and the time evolution of entanglement in open quantum systems of variable structure and dimension. Also a first experimental implementation is briefly discussed.
Źródło:
Acta Physica Polonica A; 2007, 112, 4; 575-588
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparison of phenolic profile and in vitro antioxidant capacity of Sorbus domestica L. leaf samples from Poland and Croatia
Autorzy:
Rutkowska, M.
Dybicka, M.
Olszewska, M.A.
Powiązania:
https://bibliotekanauki.pl/articles/2117865.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
antioxidant activity
extract quality
LC-MS
leaves
polyphenolic composition
Sorbus
domestica L.
Opis:
This work presents a comparative analysis of the phenolic composition (UHPLC-PDA-ESI-MS 3 , HPLC-PDA- fingerprint, UV-spectrophotometric methods) and antioxidant activity (DPPH, FRAP) of leaf samples from two vegetation seasons of a medicinal and dietary plant Sorbus domestica growing in its natural habitat (Croatia, C) and cultivated in Poland (P). The samples from both sources were rich in structurally diverse polyphenols (44 analytes; P: 73.4–76.6 and C: 98.3–106.7 mg GAE/g dry leaves) including the dominating flavan-3-ols and flavonoids. The greatest qualitative and quantitative differences were observed for flavonoids (P: 14.3–20.3%; C: 27.5–34.1% of polyphenols) – in the Polish samples flavonoid diglycosides predominated, in the Croatian samples the contents of both monoglycosides and diglycosides were similar. In the case of dry methanolic extracts, despite the higher extraction efficiency obtained for the Croatian samples (32–36% vs 23–24%), the quality of the extracts was comparable, both in terms of the total phenolic content (P: 269.4–280.0; C: 297.6–304.4; mg GAE/g dry extract) and antioxidant activity parameters (DPPH, EC 50 , μg/mL. P: 10.5–10.9, C: 10.0–10.3; and FRAP, mmol Fe 2+/g, P: 6.64–7.13, C: 7.06–7.11). As a result, the study confirmed the influence of environmental conditions on the phenolic profile and antioxidant capacity of S. domestica leaves, as well as showed that despite some differences, plant materials from both Poland and Croatia might be suitable for production of natural health products.
Źródło:
Acta Biologica Cracoviensia. Series Botanica; 2019, 61, 1; 63-73
0001-5296
Pojawia się w:
Acta Biologica Cracoviensia. Series Botanica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Scutellaria baicalensis: the end of the flavone biosynthesis pathway
Autorzy:
Elkin, Y.N.
Kulesh, N.I.
Shishmarev, V.M.
Kargin, V.M.
Manyakhin, A.Y.
Powiązania:
https://bibliotekanauki.pl/articles/2142056.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
Chinese skullcap
LC-MS analysis
OMe flavones
oroxylin A
root bark
wogonin
Opis:
The report demonstrates that plenty of methylated flavones of the plant, as the end product of the flavone biosynthesis pathway, are concentrated in the root bark, which largely remains in the waste that makes up 7% w/w of the commercial root and is discarded. The study of the waste extract showed that the last enriched with monomethylated flavones wogonin and oroxylin A, along with some polymethylated ones represent an end of the biosynthesis pathway of flavones in the plant. In addition to wogonin, 7 known methylated flavones were found for the first time in the root bark. Due to a high content of wogonin and oroxylin A in the extract, these flavones were concentrated using preparative liquid chromatography. As a result, the obtained complex of these two target flavones turned out to be 0.8% w/w of the waste. Such morphologically specific accumulation of methylated flavones at the root boundary raises the question of their role in plant life.
Źródło:
Acta Biologica Cracoviensia. Series Botanica; 2022, 64, 1; 39-43
0001-5296
Pojawia się w:
Acta Biologica Cracoviensia. Series Botanica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Quantum Cryptography with Macroscopic Photon-Number-Correlated Light
Autorzy:
Raymer, M. G.
Funk, A. C.
Powiązania:
https://bibliotekanauki.pl/articles/2030477.pdf
Data publikacji:
2002-03
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
03.67.Dd
03.67.Hk
42.50.Dv
42.50.Lc
Opis:
We describe a new scheme for performing quantum key distribution. We present two physical implementations for the quantum key distribution system. The first implementation uses a type-II optical-parametric amplifier to generate the optical pulses which contain the key information. The second implementation uses correlated semiconductor emitters to generate the optical pulses.
Źródło:
Acta Physica Polonica A; 2002, 101, 3; 437-448
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Diagonalization of a Bosonic Quadratic Form Using CCM: Application on a System with Two Interpenetrating Square Lattice Antiferromagnets
Autorzy:
Krüger, S. A.
Schmalfuss, D.
Richter, J.
Powiązania:
https://bibliotekanauki.pl/articles/2013979.pdf
Data publikacji:
2000-05
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.50.Ee
75.30.Ds
31.15.Dv
42.50.Lc
Opis:
While the diagonalization of a quadratic bosonic form can always be done using a Bogolyubov transformation, the practical implementation for systems with a large number of different bosons is a tedious analytical task. Here we use the coupled cluster method to exactly diagonalise such complicated quadratic forms. This yields to a straightforward algorithm which can easily be implemented using computer algebra even for a large number of different bosons. We apply this method on a Heisenberg system with two interpenetrating square lattice antiferromagnets, which is a model for the quasi-2D antiferromagnet Ba$\text{}_{2}$Cu$\text{}_{3}$O$\text{}_{4}$Cl$\text{}_{2}$. Using a four-magnon spin wave approximation we get a complicated Hamiltonian with four different bosons, which is treated with coupled cluster method. Results are presented for magnetic ground state correlations.
Źródło:
Acta Physica Polonica A; 2000, 97, 5; 951-954
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Stochastic Mode of the Modulated Structure in [N(CH$\text{}_{3}$)$\text{}_{4}$]$\text{}_{2}$MeCl$\text{}_{4}$ Dielectric Crystals
Autorzy:
Sveleba, S.
Semotyuk, O.
Katerynchuk, I.
Furgala, Yu.
Pankivskyi, Yu.
Powiązania:
https://bibliotekanauki.pl/articles/2046819.pdf
Data publikacji:
2006-06
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
42.25.Lc
61.44.Fw
64.70.Rh
78.20.Fm
Opis:
Temperature behavior of the optical birefringence in the transitional regions of the incommensurate phase of [N(CH$\text{}_{3}$)]CuCl$\text{}_{4}$ was studied. Temperature dependencies of the modulated structure wave vector and of the specific heat in these regions were analyzed. The stochastic mode of the incommensurate modulated structure in [N(CH$\text{}_{3}$)]MeCl$\text{}_{4}$ (Me = Cu, Fe) dielectric crystals was discovered.
Źródło:
Acta Physica Polonica A; 2006, 109, 6; 695-700
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Adjusting output impedance using a PI controller to improve the stability of a single-phase inverter under weak grid
Autorzy:
Jiao, J.
Nelms, R. M.
Powiązania:
https://bibliotekanauki.pl/articles/136224.pdf
Data publikacji:
2016
Wydawca:
EEEIC International Barbara Leonowicz Szabłowska
Tematy:
grid impedance
inverter output impedance
LC filter
PI controller
single-phase inverter
Opis:
Explored in this paper is the grid impedance effect on the stability of a single-phase grid connected inverter with an LC filter based on an analysis of the inverter output impedance. For a single-phase grid connected inverter, a PI controller is often used to regulate the current injected into the grid. However, the control performance can be influenced when the inverter is connected to a weak grid. Also, the utility grid has background harmonic noise, which can make the injected current distorted. Therefore, analysis of the output impedance of a single-phase grid connected inverter is important for the robustness and stability of the system. By modeling the output impedance of inverter, it can be determined that the proportional gain and integral gain of the controller have an effect on the output impedance. Analytical results show that by adjusting the PI controller parameters, the ability for harmonic reduction and stability of the system can be improved. Simulation and experiments using a 1 kW single-phase grid connected inverter verify the effectiveness of the theoretical analysis.
Źródło:
Transactions on Environment and Electrical Engineering; 2016, 1, 4; 50-57
2450-5730
Pojawia się w:
Transactions on Environment and Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Theoretical Studies of Tunnel Magnetoresistance and Shot Noise in a Schottky-Barrier Carbon Nanotube Transistor with Ferromagnetic Contacts
Autorzy:
Krompiewski, S.
Powiązania:
https://bibliotekanauki.pl/articles/1813866.pdf
Data publikacji:
2008-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
85.75.Hh
75.47.De
42.50.Lc
73.63.Fg
Opis:
A Schottky-barrier carbon nanotube field-effect transistor with ferromagnetic contacts was modelled. The theoretical method combines a tight-binding model and the non-equilibrium Green function technique. Tunnel magnetoresistance as well as current noise of the carbon nanotube field-effect transistor are the main issues addressed in this study. It is shown that the former may exceed 50%, whereas the latter is characterized by the Poissonian Fano factor (F) within the sub-threshold region, and the sub-Poissonian F≈0.5 for elevated gate voltages. Remarkably, reorientation of relative magnetization alignments of the contacts may lead to noticeable changes in the current noise.
Źródło:
Acta Physica Polonica A; 2008, 113, 1; 521-524
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-50 z 93

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