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Tytuł:
On the Interaction of Resonance And Bragg Scattering Effects for the Locally Resonant Phononic Crystal with Alternating Elastic and Fluid Matrices
Autorzy:
Yuan, B.
Chen, Y.
Jiang, M.
Tang, S.
He, M.
Tu, M.
Powiązania:
https://bibliotekanauki.pl/articles/177103.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
locally resonant phononic crystals
effective speed of sound
coupling band gaps
underwater acoustic materials
Opis:
Three-dimensional (3D) locally resonant phononic crystals (LRPCs) are studied with the aim of optimising the sub-wavelength band gaps of such composites. By analysing their effective acoustic properties, it has been found that the effective acoustic speed of the composite will drop to zero when local resonance arise, and will increase monotonically when Bragg scattering effects occur. Moreover, if the matrix is a low-shear-speed medium, local resonators can significantly reduce the effective acoustic speed of the composite and, therefore, lower the frequency where Bragg scattering effects occur. Hence, a specific LRPC with alternating elastic and fluid matrices is proposed, whose resonance and Bragg gaps are already close in frequency. The fluid matrix behaves as a wave filter, which prevents the shear waves from propagating in the composite. By using the layer-multiple-scattering theory, the coupling behaviour of local resonance and Bragg scattering band gaps has been investigated. Both gaps are enhanced when they move closer to each other. Finally, a gap-coupled case is obtained that displays a broad sub-wavelength band gap. Such proposal excels at the application of underwater acoustic materials since the arrangement of structure can be handily adjusted for tuning the frequency of coupled gap.
Źródło:
Archives of Acoustics; 2017, 42, 4; 725-733
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Enhancing SO2 removal efficiency by lime modified with sewage sludge in a novel integrated desulfurization process
Autorzy:
Qin, L.
Han, J.
Chen, W.
Liu, Z.
He, M.
Xing, F.
Powiązania:
https://bibliotekanauki.pl/articles/950037.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
sewage sludge
steel industry
sintering process
osad ściekowy
przemysł hutniczy
proces spiekania
Opis:
In China, the sintering process annually emitted around 1.5 million t SO2, representing 70% of SO2 produced from the iron and steel industry. Lime based sorbent was modified with municipal sewage sludge (MSS) and the influence of the modification on the desulfurization efficiency was investigated in a laboratory-scale novel integrated desulfurization (NID) reactor. The properties of modified sorbent were characterized by the Brunauer–Emmett–Teller (BET) analyzer and X-ray fluorescence (XRD) analyzer. BET surface area was increased from 17.48 to 46.68 m2g–1. when the MSS/lime ratio increased from 0 to 0.08. Ca4Al8Si8O32, Ca1.5SiO3.5, Na2Si2O5 and CaSiO3 found in the modified lime benefited for the increase of the BET surface area and pore volume. The effects of sewage sludge/CaO weight ratio, calcination temperature and hydration time on the desulfurization efficiency were also studied. SO2 removal efficiency was increased from 88.7% to 97.3% after using the lime modified with sewage sludge.
Źródło:
Environment Protection Engineering; 2017, 43, 4; 17-27
0324-8828
Pojawia się w:
Environment Protection Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Proteins and enzymatic systems in three varieties of Helianthus annuus L.
Autorzy:
Kalinowski, A
Klimko, M.
He, L.
Kluza, M.
Powiązania:
https://bibliotekanauki.pl/articles/878224.pdf
Data publikacji:
2001
Wydawca:
Uniwersytet Przyrodniczy w Poznaniu
Tematy:
variability
Helianthus annuus
enzyme
hybrid
electrophoresis
protein
enzyme system
oil plant
isoelectric focusing
Opis:
The paper reports results of analysis of protein and eight enzymatic systems of three varieties of Helianthus annuus L. (Wielkopolski, Coril, and Frankasol) performed by three electrophoretic methods. Electrophoretic analyses allowed finding protein and isoenzymes markers for each of variety. The two interline hybrids Coril and Frankasol shared more features in common than the population variety Wielkopolski with each of the former. Mean values of the polymorphism index for the protein and the eight enzymes indicate that the variety Wielkopolski is more homogeneous than Coril and Frankasol.
W pracy przedstawiono wyniki analiz białek i ośmiu układów enzymatycznych, rozdzielanych trzema metodami elektroforezy, u trzech odmian Helianthus annuus L. (Wielkopolski, Coril i Frankasol). Elektroforetyczne analizy umożliwiły znalezienie białkowych i izoenzymatycznych markerów dla trzech odmian. U dwóch odmian międzyliniowych mieszańców Coril i Frankasol wykryto więcej cech wspólnych niQ u wymienionych odmian i odmiany Wielkopolski. Średnie wartości indeksu polimorfizmu, obliczone dla białek i ośmiu układów enzymatycznych, pokazały, że odmiana Wielkopolski była bardziej wyrównana niż odmiany Coril i Frankasol.
Źródło:
Roczniki Akademii Rolniczej w Poznaniu. Botanika; 2001, 04
1508-9193
Pojawia się w:
Roczniki Akademii Rolniczej w Poznaniu. Botanika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Stability and Hopf bifurcation analysis for a Lotka-Volterra predator-prey model with two delays
Autorzy:
Xu, C.
Liao, M.
He, X.
Powiązania:
https://bibliotekanauki.pl/articles/907822.pdf
Data publikacji:
2011
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
opóźnienie
stabilność
bifurkacja Hopfa
predator-prey model
delay
stability
Hopf bifurcation
Opis:
In this paper, a two-species Lotka-Volterra predator-prey model with two delays is considered. By analyzing the associated characteristic transcendental equation, the linear stability of the positive equilibrium is investigated and Hopf bifurcation is demonstrated. Some explicit formulae for determining the stability and direction of Hopf bifurcation periodic solutions bifurcating from Hopf bifurcations are obtained by using normal form theory and center manifold theory. Some numerical simulations for supporting the theoretical results are also included.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2011, 21, 1; 97-107
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Josephson Junctions Like Behavior in Superconducting Nb Films with Diluted Triangular Arrays of Antidots
Autorzy:
Mumtaz, M.
He, S.
Qiu, X.
Kamran, M.
Powiązania:
https://bibliotekanauki.pl/articles/1192515.pdf
Data publikacji:
2015-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
74.25.F-
74.78.-w
74.81.Fa
Opis:
We present current versus voltage (I-V) measurement on superconducting Nb films with diluted triangular arrays (honeycomb and kagome) of antidots. Peaks and dips appearing in the derivative (dV/dI) of I-V curves showing the variation in the resistance is the indication of Josephson Junctions like weak-links in these systems. These observations also reveal the presence of mobile interstitial vortices in these lattices with regular pinning arrays. This behavior is predominant in honeycomb arrays due to large density of interstitial spaces in this system as compared that of to kagome lattice. This behavior can be tuned by temperature as well as external magnetic field but the tuning values of these parameters can be different for different symmetries of antidots.
Źródło:
Acta Physica Polonica A; 2015, 127, 4; 898-900
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Design and test of a new high-current electronic current transformer with a Rogowski coil
Autorzy:
Zhang, M.
Li, K.
He, S.
Wang, J.
Powiązania:
https://bibliotekanauki.pl/articles/221051.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Rogowski coil
high-current
electronic current transformers
electrical measurements
Opis:
This paper describes the design and test of a new high-current electronic current transformer based on a Rogowski coil. For better performances, electronic current transformers are used to replace conventional electro-magnetic inductive current transformers based on ferromagnetic cores and windings to measure high-current on the high voltage distribution grids. The design of a new high-current electronic current transformer is described in this paper. The principal schemes of the prototype and partial evaluation results are presented. Through relative tests it is known that the prototype has a wide dynamic range and frequency band, and it can allow high accuracy measurements.
Źródło:
Metrology and Measurement Systems; 2014, 21, 1; 121-132
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dry beneficiation and cleaning of chinese high-ash coarse coal utilizing a dense-medium gas-solid fluidized bed separator
Autorzy:
He, J.
Tan, M.
Zhu, R.
Luo, Z.
Powiązania:
https://bibliotekanauki.pl/articles/110808.pdf
Data publikacji:
2016
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
coal cleaning
dense-medium fluidized bed
density distribution
segregation
separation performance
Opis:
Dry dense-medium fluidized bed separation provides a new alternative approach for coal beneficiation and cleaning. An indicator of segregation degree Sash was proposed to evaluate the stratified performance of coal samples by bed density. Fluidization stability of the bed was greatly enhanced by mixing a certain amount (21.53%) of fine magnetite powder (< 0.15 mm) into the fluidized media, which indicated a uniform density distribution as well as slight fluctuations in bed. It was found that the favorable density-segregation performance of 3–13 mm coarse coal occurred with a static bed height of 80 mm and a superficial gas velocity of 11.84 cm/s. The optimal segregation degree values of 0.67, 0.74 and 0.76 were obtained for 3–6, 6–10 and 10–13 mm coal samples, respectively. Low-ash clean coal with yields of 50.79, 56.83 and 61.24% were effectively acquired by the dry separation for various coal size fractions, respectively. Probable error values of 0.07, 0.055 and 0.05 g/cm3 were achieved, indicating good separation performance.
Źródło:
Physicochemical Problems of Mineral Processing; 2016, 52, 2; 662-675
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An on-site calibration system for electronic instrument transformers based on LabVIEW
Autorzy:
Zhang, M.
Li, K.
Wang, J.
He, S.
Powiązania:
https://bibliotekanauki.pl/articles/221656.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
calibration system
electronic instrument transformers
data acquisition
data synchronization
LabVIEW
Opis:
Electronic voltage transformers (EVT) and electronic current transformers (ECT) are important instruments in a digital substation. For simple, rapid and convenient development, the paper proposed an on-site calibration system for electronic instrument transformers based on LabVIEW. In the system, analog signal sampling precision and dynamic range are guaranteed by the Agilent 3458A digital multimeter, and data synchronization is also achieved based on a self-developed PCI synchronization card. To improve the measurement accuracy, an error correction algorithm based on the Hanning window interpolation FFT has good suppression of frequency fluctuation and inter-harmonics interference. The human-computer interface and analysis algorithm are designed based on LabVIEW, and the adaptive communication technology is designed based on IEC61850 9-1/2. The calibration system can take into account pairs of digital output and analog output of the electronic voltage/current transformer calibration. The results of system tests show that the calibration system can meet the requirements of 0.2 class calibration accuracy, and the actual type test and on-site calibration also show that the system is easy to operate with convenience and satisfactory stability.
Źródło:
Metrology and Measurement Systems; 2014, 21, 2; 257-270
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A statistical approach for off-line signature verification (SV)
Autorzy:
Das, M.T.
Dulger, L.C.
Dulger, H.E.
Powiązania:
https://bibliotekanauki.pl/articles/332991.pdf
Data publikacji:
2009
Wydawca:
Uniwersytet Śląski. Wydział Informatyki i Nauki o Materiałach. Instytut Informatyki. Zakład Systemów Komputerowych
Tematy:
weryfikacja podpisu
sieci neuronowe
offline signature verification (SV)
particle swarm optimization (PSO)
neural networks (NN)
chi-square test
PSO-NN
Opis:
This paper includes off line Signature Verification (SV) process with test results using the proposed algorithm Particle Swarm Optimization-Neural Network (PSO-NN) together with statistical analysis, Chi-square test. The verification process is performed in four steps. Signature images are scanned (data acquisition) and image processing is applied to make images suitable for extracting features (pre-processing). Each pre-processed image is then used to extract relevant geometric parameters (feature extraction) that can distinguish signatures of different volunteers. Finally, the proposed verification algorithm is tested on the database that includes 1350 skilled and genuine signatures taken from 25 volunteers. The Chi-square test is applied to see how the signature data fits with probability test function.
Źródło:
Journal of Medical Informatics & Technologies; 2009, 13; 33-39
1642-6037
Pojawia się w:
Journal of Medical Informatics & Technologies
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ephedrine production from suspension cultures of Ephedra alata L. callus
Autorzy:
Hegazi, G.A.
Ghareb, H.E.
Gabr, M.F.
Powiązania:
https://bibliotekanauki.pl/articles/2096962.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
shake-flask culture
in vitro
alkaloid
biotic elicitor
Aspergillus niger
yeast extract
Opis:
Ephedra alata is an important Egyptian medicinal plant with enormous applications in pharmaceutical industry. Shake-flask suspension cultures of E. alata were established from internodal segment-derived callus. The suspension cultures were treated with two biotic elicitors, namely Aspergillus niger and yeast extract, to enhance the synthesis of ephedrine – the bioactive constituent of E. alata. Ephedrine was quantified using the high performance liquid chromatography technique. Ephedrine concentration was not directly related to biomass production. Aspergillus niger and yeast extract enhanced the production of ephedrine by 2.5- to 7-fold after different durations of incubation as compared to ephedrine content in the mother plant. Treatment with the fungal elicitor A. niger extract induced the maximum accumulation of ephedrine at the concentration of 1.67%; it also increased ephedrine biosynthesis by 7-fold in 24-day-old culture as compared to the ephedrine content in the mother plant and caused higher ephedrine biosynthesis than that in the control treatment without elicitors. The present protocol could be applicable for the large-scale production of ephedrine from E. alata.
Źródło:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology; 2020, 101, 1; 25-33
0860-7796
Pojawia się w:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Differential responses of aquatic and aerobic forms of Echinochloa crus-galli (L.) Beauv. and E. colona (L.) Link. by morpho-physiological and molecular analysis
Autorzy:
Khedr, A.-H.A.
Serag, M.M.
Shaaban, H.E.
Abogadallah, G.M.
Powiązania:
https://bibliotekanauki.pl/articles/9989.pdf
Data publikacji:
2017
Wydawca:
Fundacja na Rzecz Młodych Naukowców
Tematy:
alcohol dehydrogenase
ADH zob.alcohol dehydrogenase
aquatic form
aerobic form
Echinochloa crus-galli
Echinochloa colona
habitat alteration
morphophysiological analysis
molecular analysis
phosphoenolopyruvate carboxylase
Rubisco
Opis:
Echinochloa crus-galli and E. colona are serious weeds around the world. Morphological and biochemical features of aquatic and aerobic forms of both species were investigated experimentally by transplanting the seedlings reciprocally between water-saturated and aerobic soils (70% field capacity). When the plants were grown in water-saturated soil, a significant decrease in tiller height was observed in E. crus-galli, but not in E. colona. Upon growing the plants in aerobic soil, internode length and spike dry weight increased significantly in E. crus-galli, but decreased significantly in E. colona. Growth under aerobic condition caused a significant increase in PEPC/Rubisco ratio, but a significant decrease was observed under water-saturated conditions. When E. crus-galli was transplanted in aerobic soil, several forms of peroxidase were upregulated. Contrarily, in E. colona peroxidase isoforms did not respond to habitat change. Gene expression of ADH in E. colona was constitutive at a fairly high level under native habitats then enhanced with reversing habitat that caused anoxic and mild drought conditions. Both species tend to grow faster under aerobic conditions by modifying the photosynthetic machinery and capacity of scavenging of reactive oxygen species. Furthermore, ADH appears to play a role in supporting growth under water-saturated conditions.
Źródło:
Environment, Earth and Ecology; 2017, 1, 1
2543-9774
2451-4225
Pojawia się w:
Environment, Earth and Ecology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Automatic calibration system for digital-display vibrometers based on machine vision
Autorzy:
He, W.
Xu, G.
Rong, Z.
Li, G.
Liu, M.
Powiązania:
https://bibliotekanauki.pl/articles/221163.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
image recognition
calibration
vibration measurement
machine vision
automatic testing
digital-display vibrometer
Opis:
Considering the low efficiency during the process of traditional calibration for digital-display vibrometers, an automatic calibration system for vibrometers based on machine vision is developed. First, an automatic vibration control system is established on the basis of a personal computer, and the output of a vibration exciter on which a digital-display vibrometer to be calibrated is installed, is automatically adjusted to vibrate at a preset vibration level and a preset frequency. Then the display of the vibrometer is captured by a digital camera and identified by means of image recognition. According to the vibration level of the exciter measured by a laser interferometer and the recognized display of the vibrometer, the properties of the vibrometer are calculated and output by the computer. Image recognition algorithms for the display of the vibrometer with a high recognition rate are presented, and the recognition for vibrating digits and alternating digits is especially analyzed in detail. Experimental results on the built-up system show that the prposed image recognition methods are very effective and the system could liberate operators from boring and intense calibration work for digital-display vibrometers.
Źródło:
Metrology and Measurement Systems; 2014, 21, 2; 317-328
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Combined Influence of Silicon Content and Oxygen Concentration on the Oxidation Process of Silicon-Containing Steels
Autorzy:
Yuan, Q.
Xu, G.
Zhou, M.
He, B.
Hu, H.
Powiązania:
https://bibliotekanauki.pl/articles/352126.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
silicone content
oxygen concentration
mass gain
isothermal holding time
Opis:
The combined influence of silicon content and oxygen concentration on silicon-containing steels was investigated, via a heating route similar to that applied in the industrial reheating process, using a Simultaneous Thermal Analyzer (STA). Four different oxygen concentrations and three different isothermal holding times were designed. The results show that the effect of silicon on the mass gain depends on the oxygen concentration and the oxidation time. The mass gain of low-silicon steel is greater than that of high-silicon steel at 1260°C in the oxygen concentrations of 1.0 vol.% and 2.0 vol.%, even when the isothermal holding time is 90 minutes. However, there is a critical time point for mass gain in oxygen concentrations ≥3.0 vol.%. The mass gain of lowsilicon steel is greater before and smaller after this critical point. The critical time is deferred with decreasing oxygen concentration.
Źródło:
Archives of Metallurgy and Materials; 2018, 63, 1; 445-450
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The mRNA sequence polymorphisms of flowering key genes in bolting sensitive or tolerant sugar beet genotypes
Autorzy:
Alimirzaee, M.
Mirzaie-Asl, A.
Abdollahi, M.R.
Kolaei, H.E.
Fasahat, P.
Powiązania:
https://bibliotekanauki.pl/articles/79841.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
sugar-beet
Beta vulgaris ssp.maritima
mRNA
polymorphism
flowering
single nucleotide polymorphism
genetic control
RNA extraction
protein structure prediction
Źródło:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology; 2017, 98, 3
0860-7796
Pojawia się w:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Survival potential of Phytophthora infestans sporangia in relation to environmental factors and late blight occurrence
Autorzy:
Olanya, O.M.
Anwar, M.
He, Z.
Larkin, R.P.
Honeycutt, C.W.
Powiązania:
https://bibliotekanauki.pl/articles/65009.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
survival
Phytophthora infestans
sporangia
environmental factor
late blight
occurrence
climate variability
potato
tomato
Opis:
Potato is an important crop globally and late blight (Phytophthora infestans) often results in severe crop loss. The cost for late blight control can be in excess of $210 million in the United States. We utilised a non-parametric density distribution analysis of local temperature (T) and relative humidity (RH), from 2005 to 2009, to assess and validate sporangia survival potential using survival model and late blight risks during the potato cropping season at Presque Isle, in the northern part of the state of Maine, USA. Modelbased analyses showed that ambient temperatures of 3−30°C and RH values of 45−100% were conducive for sporangia survival. Disease outbreaks and risk periods coincided with a high sporangia survival probability (15−35%). Due to the omission of solar radiation (SR) in the computation of survival potential in previous research, we applied a Cox proportional model to estimate the probability of sporangia survival [i.e. hazard at a specific time H(t)] as a function of baseline hazard (H0) and the influencing parameters. The model is: H(t) = H0(t) × exp(0.067ET + 0.138T + 0.083RH + 0.001SR) where ET is exposure time. The survival model indicated that RH (β = 0.083) and T (β = 0.138) were significant (p < 0.05) factors in sporangia survival in comparison to SR (β = 0.001). The hazard ratio, indicative of sporangia survival risk, varied with the predictors. For the unit increase of T, sporangia survival hazard increased by 1.148 times. The Cox model and sporangia hazard probabilities can be used for short-term disease forecasts based on the risk period most conducive for pathogen survival and targeted fungicide applications for optimum late blight management.
Źródło:
Journal of Plant Protection Research; 2016, 56, 1
1427-4345
Pojawia się w:
Journal of Plant Protection Research
Dostawca treści:
Biblioteka Nauki
Artykuł
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