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Tytuł:
Wykrywanie bakterii Salmonella metodami molekularnymi w produktach żywnościowych
Detection of Salmonella sp. in food using molecular methods
Autorzy:
Misiewicz, A.
Goncerzewicz, A.
Powiązania:
https://bibliotekanauki.pl/articles/796639.pdf
Data publikacji:
2013
Wydawca:
Szkoła Główna Gospodarstwa Wiejskiego w Warszawie. Wydawnictwo Szkoły Głównej Gospodarstwa Wiejskiego w Warszawie
Tematy:
produkty spozywcze
bakterie
Salmonella
wykrywanie drobnoustrojow
metody molekularne
lancuchowa reakcja polimerazy
food product
bacteria
microorganism detection
molecular method
polymerase chain reaction
Opis:
Bakterie z rodzaju Salmonella są najbardziej znanymi bakteriami patogennymi występującymi w przemyśle spożywczym. Powodują zakażenia prawie wszystkich produktów żywnościowych – od mięsnych, mlecznych, jajecznych po rośliny oleiste i pasze. Wykrycie i identyfi kacja bakterii Salmonella na podstawie tradycyjnej metody mikrobiologicznej, zgodnie z normą PN-EN 6579:2003, jest ciągle powszechnie stosowane w laboratoriach. Analiza ta jest czaso- i pracochłonna, jej wykonanie trwa około 5–7 dni. Wykorzystanie nowoczesnych technik biologii molekularnej, z etapem namnożenia i izolacji DNA, do uzyskania końcowego wyniku trwa znacznie krócej. W niniejszej pracy zastosowano metodę Real-Time PCR i klasyczny PCR do identyfi kacji bakterii Salmonella w różnych produktach żywnościowych. Określono czas potrzebny do wykonania tej analizy molekularnej. Do reakcji Real-Time PCR wykorzystano komercyjny kit. Klasyczną reakcję PCR prowadzono z użyciem starterów Sal465Li Sal142F, uzyskując właściwy produkt o wielkości 343 pz. We wszystkich badanych próbkach wykryto bakterie Salmonella. Wynik analiz molekularnych uzyskano w ciągu 21–25 godzin.
Pathogenic bacteria of Salmonella genus are the most common infections in food industry. They might to contaminate wide range of products, protein food e.g. meat, milk food, eggs and egg foods, plants and its preserves, fodder and feeds. Detection and identifi cation of Salmonella sp. are made using traditional methods corresponding with standard PN-EN 6579:2003. That method is commonly used in the microbiological laboratories its time consuming and laborious analysis. Using a modern molecular biology techniques allow to confi rm the Salmonella infections in 24-hours with enrichment and isolation steps. In our study were used Real-Time PCR and traditional PCR techniques to detect Salmonella pathogens from various foods. In addition we checked time of molecular analysis. In the study was used commercial kit to Real-Time PCR analysis and primer set Sal465L, Sal142F with are based on characteristic and solid genomic fragments of Salmonella genus. In every experiment we got positive results for food contaminated by Salmonella. The results were obtained in 21–25 hours.
Źródło:
Zeszyty Problemowe Postępów Nauk Rolniczych; 2013, 573
0084-5477
Pojawia się w:
Zeszyty Problemowe Postępów Nauk Rolniczych
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Przemienniki częstotliwości w układzie technologicznym ciepłowni o mocy 100 MWt
The variable frequency drives in technological plants of 100 MWt thermal power station
Autorzy:
Murawski, M.
Misiewicz, A.
Powiązania:
https://bibliotekanauki.pl/articles/1367493.pdf
Data publikacji:
2016
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Napędów i Maszyn Elektrycznych Komel
Tematy:
przemienniki częstotliwości
pompy wirowe, regulacja
zasilanie elektryczne
sterowanie
frequency converters
centrifugal pumps
adjustment
electric supply
control
Opis:
Using of variable frequency drives is now the most common method for adjusting the hydraulic parameters. However, without the right order in the technology systems and proper parameters selection it is not possible to adjust with enough positive energetic effect. This paper presents the modification of hydraulic system of 100 MWt heating plant, with the frequency variable drives, working under new steering algorithm. The deep adjustment causes the lowering of pumps, drives and motors efficiency. In new, modernized system, after correcting the hydraulic parameters of pumps, with the new drives, the total pumping efficiency is growing. This paper presents the realistic energetic effects realized as an effect of the right technology projects with New drives. It presents the solutions in the field of the electrical power supply, adjustment and steering, causing the higher energetic efficiency of whole heating plant system.
Stosowanie regulowanych układów napędowych w pompach sieciowych źródeł ciepła jest obecnie najczęstszym sposobem regulacji parametrów hydraulicznych. Jednak bez uporządkowania technologii pompowania oraz właściwego doboru parametrów pomp nie można mówić o regulacji efektywnej. W referacie przedstawiona została modernizacja układu wodnego ciepłowni o mocy 100 MWt, z wykorzystaniem układów napędowych, pracujących wg nowych algorytmów regulacji. Konieczność głębokiej regulacji powodowała nieuniknione spadki sprawności pomp, silników i napędów (przemienników częstotliwości). W zmodernizowanym układzie, po wcześniejszym dostosowaniu parametrów hydraulicznych pomp do potrzeb (charakterystyki oporu układu), z nowo dobranymi napędami, uzyskano znaczną poprawę sprawności pompowania. Artykuł przedstawia rzeczywiste efekty energetyczne uzyskane w wyniku prawidłowego zaprojektowania technologii i odpowiedniego doboru zespołów (pompa-silnik-przemiennik). Prezentuje rozwiązania z zakresu zasilania, sterowania i regulacji co skutkuje poprawą sprawności energetycznej układu technologicznego ciepłowni.
Źródło:
Maszyny Elektryczne: zeszyty problemowe; 2016, 3, 111; 13-19
0239-3646
2084-5618
Pojawia się w:
Maszyny Elektryczne: zeszyty problemowe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Techniczne i ekonomiczne efekty zastosowania nowoczesnych układów regulacji prędkosci w pompach ciepłowniczych
The economical and technical consequences of applying variable speed drives for pumps in the heating plants
Autorzy:
Pozowski, A.
Misiewicz, A.
Powiązania:
https://bibliotekanauki.pl/articles/1374299.pdf
Data publikacji:
2007
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Napędów i Maszyn Elektrycznych Komel
Tematy:
pompa
układ pompowy
regulacja prędkości
Opis:
The paper presents the results of applying the variable speed drives as a drives for main pumps in the heating plants and systems. Using only variable-speed drives don't guarantee the good results and efficiency. Also, very important are the good parameters of the pump and technology of water systems. The paper presents the application of the new drives in the 300 MW heating plants. In the first step the head of pumps had been changed, the next technology systems and in the end the two 900 kW electric power drives were mounted. Also the possibilities for quick reaction and adjustable of pumps were upgraded. The article also presents the details of configuration of variable-speed drives installed in the heating plants. The results of the one year work and economical effects have been described. The financial effects are about a half million PLN per year.
Źródło:
Maszyny Elektryczne: zeszyty problemowe; 2007, 78; 53-58
0239-3646
2084-5618
Pojawia się w:
Maszyny Elektryczne: zeszyty problemowe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The characteristics of some brewers yeast strains - short report
Autorzy:
Misiewicz, A.
Ilnicka-Olejniczak, O.
Powiązania:
https://bibliotekanauki.pl/articles/1372695.pdf
Data publikacji:
1996
Wydawca:
Instytut Rozrodu Zwierząt i Badań Żywności Polskiej Akademii Nauk w Olsztynie
Tematy:
biotechnological property
brewery yeast
preservation
fermentation velocity
yeast strain
fermentation energy
Opis:
Some of the industrial brewer's yeasts strains preserved in the collection of the Institute of Agro-Food Biotechnology for 35 years were studied. Fermentation energy and velocity, apparent attenuation and yeast sediment layer was checked according to methods used in the Institute.
Źródło:
Polish Journal of Food and Nutrition Sciences; 1996, 05, 1; 95-99
1230-0322
2083-6007
Pojawia się w:
Polish Journal of Food and Nutrition Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Skład pokarmu wybranych ssaków drapieżnych na terenie Gorczańskiego Parku Narodowego
Diet composition of carnivore species in the Gorce National Park
Autorzy:
Gaspar, G.
Wierzbowska, I.A.
Misiewicz, A.
Armatys, P.
Loch, J.
Czarnota, P.
Wierzbowski, J.
Powiązania:
https://bibliotekanauki.pl/articles/985769.pdf
Data publikacji:
2018
Wydawca:
Polskie Towarzystwo Leśne
Tematy:
Canis lupus
parki narodowe
Gorczanski Park Narodowy
ssaki drapiezne
wilk
rys
Lynx lynx
lis pospolity
Vulpes vulpes
kuna lesna
Martes martes
sklad pokarmu
analiza skladu pokarmu
ssaki kopytne
drobne ssaki
nisze pokarmowe
canis lupus
lynx lynx
vulpes vulpes
martes martes
ungulates
the carpathians
Opis:
The aim of the study was to assess the diet composition of four carnivore species inhabiting the Gorce National Park (Western Carpathians, S Poland), i.e., grey wolf (Canis lupus), Eurasian lynx (Lynx lynx), red fox (Vulpes vulpes), and pine marten (Martes martes). The food analysis was based on scats collected between June 2016 and February 2017 along seven transects of a total length 96.13 km. Altogether 187 faeces were found, 95 of grey wolf, 20 of lynx, 49 of red fox, and 23 of pine marten, respectively. The dominant food category of wolf and lynx were ungulates, comprising respectively 98% and 95% of the consumed biomass. The trophic niche overlap between wolf and lynx was very high (Pianka’s index Ojk=0.99). However, there were differences in the consumed prey species. Wolves fed on red deer (Cervus elaphus), roe deer (Capreolus capreolus) and wild boar (Sus scrofa), while lynxes foraged equally on two ungulates, red deer and roe deer. Medium−sized carnivores showed greater variety in consumed food. Both pine marten and red fox had higher values of Levins’ index of the trophic niche breadth than larger carnivores and highly overlapped their diets (Ojk=0.96). Pine marten and red fox consumed mostly small mammals. Additionally, martens consumed frequently fruits, whereas red foxes foraged on carrion of ungulates. This might explain the fact that wolf and lynx overlapped their trophic niches more with red fox than with the pine marten.
Źródło:
Sylwan; 2018, 162, 04; 333-342
0039-7660
Pojawia się w:
Sylwan
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Hole Subband Mixing and Polarization of Luminescence from Quantum Dashes: A Simple Model
Autorzy:
Kaczmarkiewicz, P.
Musiał, A.
Sęk, G.
Podemski, P.
Machnikowski, P.
Misiewicz, J.
Powiązania:
https://bibliotekanauki.pl/articles/2048063.pdf
Data publikacji:
2011-05
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.67.Hc
73.22.-f
Opis:
In this paper, we address the problem of luminescence polarization in the case of nanostructures characterized by an in-plane shape asymmetry. We develop a simple semi-qualitative model revealing the mechanism that accounts for the selective polarization properties of such structures. It shows that they are not a straightforward consequence of the geometry but are related to it via valence subband mixing. Our model allows us to predict the degree of polarization dependence on the in-plane dimensions of investigated structures assuming a predominantly heavy hole character of the valence band states, simplifying the shape of confining potential and neglecting the influence of the out-of-plane dimension. The energy dependence modeling reveals the importance of different excited states in subsequent spectral ranges leading to non-monotonic character of the degree of polarization. The modeling results show good agreement with the experimental data for an ensemble of InAs/InP quantum dashes for a set of realistic parameters with the heavy-light hole states separation being the only adjustable one. All characteristic features are reproduced in the framework of the proposed model and their origin can be well explained and understood. We also make some further predictions about the influence of both the internal characteristics of the nanostructures (e.g. height) and the external conditions (excitation power, temperature) on the overall degree of polarization.
Źródło:
Acta Physica Polonica A; 2011, 119, 5; 633-636
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Shake-Up Processes in Photoluminescence of Two-Dimensional Holes in a High Magnetic Field
Autorzy:
Wójs, A.
Bryja, L.
Misiewicz, J.
Potemski, M.
Reuter, D.
Wieck, A.
Powiązania:
https://bibliotekanauki.pl/articles/2047047.pdf
Data publikacji:
2006-09
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.35.Cc
71.35.Ji
73.21.Fg
Opis:
Recombination of excitons and positive trions is studied by two-beam photoluminescence of a two-dimensional hole gas in a high magnetic field. The singlet, dark-triplet and bright-triplet states of a free trion are resolved, and their binding energies are determined. Recombination of acceptor-bound trions is also detected, including a low-energy cyclotron replica, corresponding to a hole shake-up process. Identification of all these different transitions was possible by analysis of optical selection rules and the comparison of experimental spectra with realistic numerical calculations.
Źródło:
Acta Physica Polonica A; 2006, 110, 3; 429-435
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Oscillator strength of optical transitions in InGaAsN/GaAsN/GaAs quantum wells
Autorzy:
Mika, A
Sek, G
Ryczko, K
Kozub, M
Musial, A
Marynski, A
Misiewicz, J
Langer, F
Höfling, S
Appel, T
Kamp, M
Forchel, A
Powiązania:
https://bibliotekanauki.pl/articles/173586.pdf
Data publikacji:
2013
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
dilute nitride
quantum well
oscillator strength
Opis:
Experimental and theoretical considerations and results on the effect of nitrogen incorporation on the oscillator strength of optical transitions in InGaNAs/GaAs quantum wells (QWs) are presented. Therefore, a set of dilute nitride quantum well structures was grown by molecular beam epitaxy. Optical investigation via spectroscopic methods have been performed at various temperatures for both the as-grown samples, and after rapid thermal annealing. The fundamental transition energy and its oscillator strength vs. the QW composition have been systematically investigated. Additionally, the effect of the bandgap discontinuities on the transitions intensity has also been considered. The experimental data have been confronted with the band structure calculations within the effective mass approximation employing a two level repulsion model for the nitrogen-containing structures. The obtained results are crucial for possible future applications employing the quantum well in cavity structures and bringing the practical exploitation of quantum electrodynamics phenomena to the telecommunication spectral range.
Źródło:
Optica Applicata; 2013, 43, 1; 53-60
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experimental and Theoretical Studies of Free and Acceptor-Bound Positive Magneto-Trions
Autorzy:
Bryja, L.
Wójs, A.
Płochocka-Polack, P.
Gładysiewicz, A.
Misiewicz, J.
Potemski, M.
Powiązania:
https://bibliotekanauki.pl/articles/2047714.pdf
Data publikacji:
2007-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.55.Cn
71.35.Ji
73.21.Fg
Opis:
By combination of polarization-resolved photoluminescence, transport, and realistic numerics we study energy and recombination spectra of free and acceptor-bound positive trions in a quasi-two-dimensional hole gas. The singlet-triplet crossing in the trion ground state is found at B≈12 T, and a slight reduction of all trion binding energies coincident with the formation of a Laughlin hole fluid is observed at B≈14.2 T.
Źródło:
Acta Physica Polonica A; 2007, 112, 2; 415-418
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Skyrmions in a Hole Gas with Large Spin Gap and Strong Disorder
Autorzy:
Bryja, L.
Ryczko, K.
Wójs, A.
Misiewicz, J.
Potemski, M.
Powiązania:
https://bibliotekanauki.pl/articles/2046907.pdf
Data publikacji:
2006-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
73.20.Mf
73.21.Fg
78.20.Ls
78.67.De
Opis:
In the photoluminescence excitation spectra of two-dimensional valence holes with large spin gap and strong disorder we find evidence for quantum Hall ferromagnetism and small skyrmions around the Landau level filling factorν=1. This interpretation is supported by numerical calculations.
Źródło:
Acta Physica Polonica A; 2006, 110, 2; 163-168
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Temperature Dependence of Photoluminescence from Epitaxial InGaAs/GaAs Quantum Dots with High Lateral Aspect Ratio
Autorzy:
Musiał, A.
Sęk, G.
Maryński, A.
Podemski, P.
Misiewicz, J.
Löffler, A.
Höfling, S.
Reitzenstein, S.
Reithmaier, J.
Forchel, A.
Powiązania:
https://bibliotekanauki.pl/articles/1492876.pdf
Data publikacji:
2011-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.67.Hc
65.80.-g
Opis:
Hereby, we present a study of a thermal quenching of emission from self-assembled epitaxial highly asymmetric quantum dots in InGaAs/GaAs material system for both ensemble and single dot regime. Pronounced interplay between the intensity of wetting layer and quantum dots originated emission was observed as the temperature was increased, evidencing a thermally activated energy transfer between the two parts of the system and an important role of the wetting layer in determining the optical properties of these anisotropic nanostructures. The carrier activation energies have been derived and possible carrier loss mechanisms have been analyzed. Single dot study revealed activation energies slightly varying from dot to dot due to size and shape distribution. The problem of the shape uniformity of individual quantum dot has also been addressed and possibility of additional carrier localization within the investigated structures has been found to be insignificant based on the recorded spectroscopic data.
Źródło:
Acta Physica Polonica A; 2011, 120, 5; 883-887
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wystepowanie larw nicieni z rodziny Protostrongylidae w slimakach ladowych w lasach olsztynskich i slaskich
Autorzy:
Misiewicz, J
Demiaszkiewicz, A.W.
Powiązania:
https://bibliotekanauki.pl/articles/840810.pdf
Data publikacji:
1994
Wydawca:
Polskie Towarzystwo Parazytologiczne
Tematy:
woj.olsztynskie
pasozyty zwierzat
slimaki
zywiciele posredni
parazytologia
Protostrongylidae
nicienie
larwy
Slask
Opis:
During the years 1992-1993 terrestrial snails were examined to the infection with larvae of Protostrongylidae family in the South and North of Poland. Using compressor method 2267 terrestrial snails from two areas (Pszczyna and Iława) were examined. Collected gastropods belonged to the following species: Arion subfuscus (45 specimens), Bradybaena fruticum (9), Cepaea nemoralis (29), Succinea putris (2147), Zonitoides nitidus (37). Larvae of three species of Protostrongylidae family were found: Elaphostrongylus cervi, Varestrongylus sagittatus and V. capreoli. The highest extensiveness of invasion of Protostrongylidae was noticed in Succinea putris and reached 23,5% in one of plots in the Iława Forest District. The highest intensity of infection was found in S. putris and was as follows: E. cervi up to 150 larvae, V. sagittatus up to 41, and V. capreoli up to 132 larvae. Besides Z. nitidus (1 specimen) there were not noticed any larvae of Protostrongylidae in other species of terrestrial snails. Average extensiveness of invasion of Protostrongylidae in 1992 and 1993 amounted to 7,2 and 9,5% in Iława, and 13,9 and 9,4% in Pszczyna, respectively. The highest percentage of infested gastropods was noticed in June and July. Similar results were obtained in both biotopes examined.
Źródło:
Annals of Parasitology; 1994, 40, 2; 167-172
0043-5163
Pojawia się w:
Annals of Parasitology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Interface and Surface Subsignals in Photoreflectance Spectra for GaAs/SI-GaAs Structures
Autorzy:
Jezierski, K.
Sitarek, P.
Misiewicz, J.
Panek, M.
Ściana, B.
Korbutowicz, R.
Tłaczała, M.
Powiązania:
https://bibliotekanauki.pl/articles/1933782.pdf
Data publikacji:
1995-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
68.55.-a
71.35.+z
Opis:
Photoreflectance spectra were measured at room temperature for energies in the vicinity of the E$\text{}_{0}$ critical point for p-type as well as n-type doped GaAs/SI-GaAs structures. Depending on the doping concentration the existence of two photoreflectance subsignals was observed; the first one arises from the surface space charge region while the second one from the interface region. The decomposition of photoreflectance spectrum into surface and interface subsignals was based on the photoreflectance measurements carried out for different wavelengths of the laser pump beam.
Źródło:
Acta Physica Polonica A; 1995, 88, 4; 751-754
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Combined Exciton-Cyclotron Resonance in Photoluminescence of a Two-Dimensional Hole Gas
Autorzy:
Jadczak, J.
Bryja, L.
Płochocka, P.
Wójs, A.
Misiewicz, J.
Maude, D.
Potemski, M.
Powiązania:
https://bibliotekanauki.pl/articles/1791299.pdf
Data publikacji:
2009-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
73.20.Mf
71.35.Ji
71.35.Pq
78.20.Ls
Opis:
A two-dimensional hole gas in an asymmetric GaAs/$Ga_{1-x}Al_{x}As$ quantum well is studied by polarization-resolved photoluminescence in high magnetic fields (up to B = 20 T) and at low temperatures (down to T = 50 mK). In addition to the previously reported dominant emission channels of various free and acceptor-bound trions, the high-energy hole cyclotron replicas of the bound states are now also observed, corresponding to the combined exciton-cyclotron resonance. Identification of different transitions in the rich, multi-peak spectra was possible by the analysis of optical selection rules and comparison of the experimental spectra with realistic numerical calculations.
Źródło:
Acta Physica Polonica A; 2009, 116, 5; 852-853
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
GaAs-Based Quantum Well Exciton-Polaritons beyond 1 μm
Autorzy:
Pieczarka, M.
Podemski, P.
Musiał, A.
Ryczko, K.
Sęk, G.
Misiewicz, J.
Langer, F.
Höfling, S.
Kamp, M.
Forchel, A.
Powiązania:
https://bibliotekanauki.pl/articles/1399094.pdf
Data publikacji:
2013-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
73.21.-b
78.67.-n
78.67.Pt
Opis:
Realization of the Bose-Einstein condensate can provide a way for creation of an inversion-free coherent light emitter with ultra-low threshold power. The currently considered solutions provide polaritonic emitters in a spectral range far below 1 μm limiting their application potential. Hereby, we present optical studies of InGaAs/GaAs based quantum well in a cavity structure exhibiting polaritonic eigenmodes from 5 to 160 K at a record wavelength exceeding 1 μm. The obtained Rabi splitting of 7 meV was almost constant with temperature, and the resulting coupling constant is close to the calculated QW exciton binding energy. This indicates the very strong coupling conditions explaining the observation of polaritons at temperatures where the exciton dissociation is already expected, and allows predicting that room temperature polaritons could still be formed in this kind of a system.
Źródło:
Acta Physica Polonica A; 2013, 124, 5; 817-820
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Light-Induced Modification of 3D Photonic Band Structure Detected by Means of PhotoreflectionD
Autorzy:
Kapitonov, A. M.
Kachan, S. M.
Ponyavina, A. N.
Gaponenko, S. V.
Bogomolov, V. N.
Prokofiev, A. V.
Sitarek, P.
Misiewicz, J.
Powiązania:
https://bibliotekanauki.pl/articles/1995551.pdf
Data publikacji:
1999-03
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
42.70.Qs
42.70.Gi
Opis:
Porous synthetic opal possessing a three-dimensional photonic band structure of semimetallic type was impregnated with polycrystalline CdS. The photonic stop band in (111) direction was examined by means of photoreflection technique. Under cw laser excitation of semiconductor inclusions the reflectance of the system changes indicating a modification of photonic band structure. A possible mechanism is discussed. Numerical simulations within the framework of quasicrystalline approximation are given.
Źródło:
Acta Physica Polonica A; 1999, 95, 3; 335-342
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of Confinement Anisotropy on Excitonic Properties in InAs/InP Quantum Dashes
Autorzy:
Mrowiński, P.
Musiał, A.
Sęk, G.
Misiewicz, J.
Höfling, S.
Somers, A.
Hein, S.
Forchel, A.
Powiązania:
https://bibliotekanauki.pl/articles/1399087.pdf
Data publikacji:
2013-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.35.-y
71.70.Gm
78.67.Hc
73.21.-b
81.07.Ta
Opis:
The influence of confinement potential anisotropy on emission properties of strongly elongated single InAs/InGaAlAs/InP quantum dashes has been investigated by polarization-resolved microphotoluminescence spectroscopy at around 1.5 μm. There have been determined the exciton fine structure splitting, degree of linear polarization of surface emission and biexciton binding energy. The investigated dashes exhibited usually: the exciton anisotropy splitting larger than 100 μeV, the corresponding biexciton binding energy of about 3 meV, and the degree of linear polarization values in the range from 24% to 55%. Here, we presented a correlation of these parameters for several quantum dashes, which can be attributed either to a change in lateral aspect ratio within the ensemble, or the carrier localization on random fluctuations of the dash confinement potential.
Źródło:
Acta Physica Polonica A; 2013, 124, 5; 801-804
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Energy Transfer Processes in InAs/GaAs Quantum Dot Bilayer Structure
Autorzy:
Pieczarka, M.
Maryński, A.
Podemski, P.
Misiewicz, J.
Spencer, P.
Murray, R.
Sęk, G.
Powiązania:
https://bibliotekanauki.pl/articles/1185237.pdf
Data publikacji:
2016-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.67.Hc
71.35.-y
78.55.-m
Opis:
We investigate double layer InAs/GaAs quantum dots grown in the Stransky-Krastanov mode by molecular beam epitaxy. The sample consists of two layers of InAs quantum dots separated by 10 nm thick GaAs layer, where the top quantum dot layer of an improved homogeneity is covered by an InGaAs cap. This configuration has allowed for the extension of the dots' emission to longer wavelengths. We probed the carrier transfer between the states confined in a double quantum well composed of InGaAs cap and the quantum dots wetting layer to the states in the quantum dots by means of photoluminescence excitation and photoreflectance spectroscopies. Efficient emission from quantum dots excited at the double quantum well ground state energy was observed. There is also presented a discussion on the carrier injection efficiency from the capping layer to the quantum dots.
Źródło:
Acta Physica Polonica A; 2016, 129, 1a; A-59-A-61
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Electronic Structure of Elongated $In_{0.3}Ga_{0.7}As//GaAs$ Quantum Dots
Autorzy:
Pieczarka, M.
Musiał, A.
Podemski, P.
Sęk, G.
Misiewicz, J.
Powiązania:
https://bibliotekanauki.pl/articles/1399091.pdf
Data publikacji:
2013-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.67.Hc
73.21.La
73.22.-f
Opis:
In this contribution the electronic structure of large $In_{0.3}Ga_{0.7}As//GaAs$ quantum dots is studied theoretically by means of 8 band k · p modeling. These quantum dots constitute unique physical system due to the low strain limit of the Stranski-Krastanow growth mode resulting in relatively large physical volume and elongation of the quantum dots in [1-10] direction. As a result of these critical growth conditions the electronic structure is expected to be very sensitive to the nanostructure size, shape, and composition of the quantum dot as well as the accompanying wetting layer. Another peculiarity of investigated system is the confining potential which is rather shallow and weakened in comparison to standard quantum dots. It makes them very interesting in view of both fundamental study and potential applications. To reveal physical mechanisms determining the optical properties of the investigated system, the electronic structure, mainly the number of confined states, and the wave function extension as a function of both quantum dot size and geometry have been simulated numerically and the importance of electron-hole Coulomb interactions has been evaluated.
Źródło:
Acta Physica Polonica A; 2013, 124, 5; 809-812
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optical Transitions between Confined and Unconfined States in p-Type Asymmetric GaAs/InGaAs/AlGaAs QW Structures
Autorzy:
Sitarek, P.
Ryczko, K.
Misiewicz, J.
Reuter, D.
Wieck, A.
Powiązania:
https://bibliotekanauki.pl/articles/1492827.pdf
Data publikacji:
2011-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
73.50.Pz
78.66.Fd
78.67.De
Opis:
We present contactless surface photovoltage spectroscopy and photoreflectance studies of 10 nm wide, p-type doped asymmetric GaAs/InGaAs/AlGaAs quantum well structures. The MBE grown structures differ in spacer thickness between the quantum well and the reservoir of holes. The doping causes that quantum well is placed in electric field. The surface photovoltage spectroscopy measurements gave us detailed information about the optical transitions between confined states and between confined and unconfined states. The comparison of experimental and numerical analysis allows us to identify all features present in the surface photovoltage spectroscopy and photoreflectance spectra. It has been found that spacer layer thickness has significant influence on surface photovoltage spectroscopy spectra.
Źródło:
Acta Physica Polonica A; 2011, 120, 5; 849-851
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Evidence of Singlet-Triplet Crossing in Photoluminescence of Positively Charged Excitons in GaAs Quantum Wells
Autorzy:
Bryja, L.
Wójs, A.
Jadczak, J.
Misiewicz, J.
Płochocka, P.
Potemski, M.
Reuter, D.
Wieck, A.
Powiązania:
https://bibliotekanauki.pl/articles/1811918.pdf
Data publikacji:
2008-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
73.20.Mf
71.35.Ji
71.35.Pq
78.20.Ls
Opis:
Positively charged excitons in a two-dimensional hole gas in symmetric and asymmetric GaAs/$Ga_{1-x}Al_{x}As$ quantum wells are studied in polarization-resolved photoluminescence experiments in high magnetic fields B (up to 23 T) and low temperatures (down to 300 mK). The experiments are accompanied by numerical calculations of a real structure. The whole family of trions (the singlet and a pair of triplets) are observed. The Coulomb energies crossing of singlet and triplet is found: hidden in symmetric and visible in asymmetric structures.
Źródło:
Acta Physica Polonica A; 2008, 114, 5; 1073-1077
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optimizing the InGaAs/GaAs quantum dots for 1.3 μm emission
Autorzy:
Maryński, A.
Mrowiński, P.
Ryczko, K.
Podemski, P.
Gawarecki, K.
Musiał, A.
Misiewicz, J.
Quandt, D.
Strittmatter, A.
Rodt, S.
Reitzenstein, S.
Sęk, G.
Powiązania:
https://bibliotekanauki.pl/articles/1055140.pdf
Data publikacji:
2017-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.30.Fs
78.67.-n
78.67.Hc
73.22.-f
Opis:
Hereby we present comprehensive experimental and theoretical study on fundamental optical properties and electronic structure of GaAs-based quantum dots grown using metalorganic chemical vapor deposition technique. The substantial redshift of emission, to the second telecommunication window of 1.3 μm, in comparison to standard InGaAs/GaAs quantum dots is obtained via strain engineering utilizing additional capping layer of In_{0.2}Ga_{0.8}As in this context referred to as strain reducing layer. It ensures lowering of the energy of the ground state transition to more application relevant spectral range. Optical properties of the quantum dot structure has been experimentally characterized by means of photoreflectance spectroscopy and power-dependent photoluminescence revealing 3 transitions originating from hybrid states confined in an asymmetric double quantum well formed of the wetting layer and strain reducing layer, as well as higher states of the quantum dots themselves with the first excited state transition separated by 67 meV from the ground state transition. Origin of the observed transitions was confirmed in theoretical modelling using 1-band single-particle approach for the quantum well part, and excitonic quantum dot spectrum obtained within 8 band k·p formalism followed by configuration interaction calculations, respectively. Additionally, photoluminescence excitation spectroscopy measurements allowed to identify a spectral range for efficient quasi-resonant excitation of the investigated quantum dots into the 2D density of states to be in the range of 835-905 nm.
Źródło:
Acta Physica Polonica A; 2017, 132, 2; 386-390
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł

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