Autor: Yu, C. W. - Prolib Integro

Skocz do pozycji: 1.

Tytuł:: Characterization of the Kenyan Hibiscus sabdariffa L. (Roselle) Bast Fibre
Charakterystyka włókien łykowych kenijskiej ketmii szczawiowej (Hibiscus sabdariffa L.)
Autorzy:: Mwasiagi, J. I.
Yu, C. W.
Phologolo, T
Waithaka, A.
Kamalha, E.
Ochola, J. R.
Tematy:: Hibiscus sabdariffa L.
roselle
bast fibre
fibre properties
FTIR
SEM
Ketmia szczawiowa
włókna łykowate
właściwości włókien; Pokaż więcej
Wydawca:: Sieć Badawcza Łukasiewicz - Instytut Biopolimerów i Włókien Chemicznych
Powiązania:: https://bibliotekanauki.pl/articles/231606.pdf Link otwiera się w nowym oknie
Opis:: Hibiscus sabdariffa L. (roselle) is grown in Kenya for its flower and calyx, which are used in the beverage industry. Roselle bast fibre has, however, not been commercially exploited. After harvesting the flowers and calyx the stem together with the bark is used as firewood. This paper reports the characteristics of bast fibres in Hibiscus sabdariffa L. (roselle) grown in Kenya. The bast fibre was characterised by studying its physical and chemical characteristics. The physical characteristics investigated included tensile properties, fineness and surface morphology. An investigation into the type of chemical ingredients present in the fibre was also undertaken. The data obtained in this study indicated that the roselle plant grown in Kenya can produce bast fibres of comparable properties to the kenaf grown in Asian countries.
Hibiscus sabdariffa L. uprawiany jest w Kenii dla kwiatów I kielichów, które stosowane są do produkcji napojów. Włókna łykowe ketmii szczawiowej nie znalazły jak dotychczas zastosowania przemysłowego. Praca przedstawia właściwości chemiczne i fizyczne uzyskanych włókien łykowych. Z właściwości fizycznych badano wytrzymałość, średnicę włókien i morfologię powierzchni. Badania chemiczne określiły zawartość różnych składników we włóknach. Na podstawie przeprowadzonych badań stwierdzono, że właściwości włókien uzyskanych z ketmii szczawiowej uprawianej w Kenii są porównywalne z właściwościami włókien ketmii konopiowatej uprawianej w Azji.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 2.

Tytuł:: Selective adsorption of anionic polyacrylamide onto ultra-low ash coal and kaolinite
Autorzy:: Zou, W.
Yu, C.
Sun, C.
Cao, Y.
Tematy:: coal
kaolinite
anionic polyacrylamide
adsorption
flotation; Pokaż więcej
Wydawca:: Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Powiązania:: https://bibliotekanauki.pl/articles/109333.pdf Link otwiera się w nowym oknie
Opis:: To study the selectivity of polyacrylamide in the selective floc flotation of fine coal, adsorption of anionic polyacrylamide (PAM A401) onto ultra-low ash coal and kaolinite was studied, including the adsorption thermodynamics, floc size distribution and wettability changes. The thermodynamics of the adsorption process at the low concentration of 0-16 mg/dm3 of PAM A401 were studied at different contact times, doses, temperatures and pH values. Thermodynamic parameters of ΔGo, ΔHo, ΔSo and Ea were evaluated to understand the nature of the adsorption process. The results indicated that PAM A401 was selectively adsorbed onto ultra-low ash coal rather than kaolinite. Physical adsorption was the predominant mechanism, and the adsorption of PAM A401 at 12 mg•dm-3 onto coal was 2.15-fold larger than the adsorption on kaolinite. After the adsorption of PAM A401, the lipophilic hydrophilic ratio (LHR) of coal decreased from 9.23 to 7.28, indicating that the coal became less hydrophobic than before. In contrast, the LHR of kaolinite increased from 1.44 to 1.65. Floc size measurements showed that the d10, d50 and d90 of coal flocculated by PAM A401 (at 12 mg/dm3, pH 6.5) were 3.18, 2.76 and 2.59-fold greater than the corresponding levels of these parameters for kaolinite flocs, respectively.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 3.

Tytuł:: Influence of different rotor magnetic circuit structure on the performance of permanent magnet synchronous motor
Autorzy:: Qiu, H.
Yu, W.
YANG, C.
Yi, R.
Tematy:: air gap flux density
cogging torque
magnetic circuit structure
overload capacity
permanent magnet synchronous motor; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:: https://bibliotekanauki.pl/articles/141061.pdf Link otwiera się w nowym oknie
Opis:: In order to compare the performance difference of the permanent magnet synchronous motors (PMSM) with different rotor structure, two kinds of rotor magnetic circuit structure with surface-mounted radial excitation and tangential excitation are designed respectively. By comparing and analyzing the results, the difference of the motor performance was determined. Firstly, based on the finite element method (FEM), the motor electromagnetic field performance was studied, and the magnetic field distribution of the different magnetic circuit structure was obtained. The influence mechanism of the different magnetic circuit structure on the air gap flux density was obtained by using the Fourier theory. Secondly, the cogging torque, output torque and overload capacity of the PMSM with different rotor structure were studied. The effect mechanism of the different rotor structure on the motor output property difference was obtained. The motor prototype with two kinds of rotor structure was manufactured, and the experimental study was carried out. By comparing the experimental data and simulation data, the correctness of the research is verified. This paper lays a foundation for the research on the performance of the PMSM with different magnetic circuit structure.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 4.

Tytuł:: Research on the influence of driving harmonic on electromagnetic field and temperature field of permanent magnet synchronous motor
Autorzy:: Qiu, H.
Yu, W.
Li, Y.
Yang, C.
Tematy:: air gap flux density
eddy current loss
harmonic
magnetic field decoupling
torque ripple; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:: https://bibliotekanauki.pl/articles/141535.pdf Link otwiera się w nowym oknie
Opis:: At present, the drivers with different control methods are used in most of permanent magnet synchronous motors (PMSM). A current outputted by a driver contains a large number of harmonics that will cause the PMSM torque ripple, winding heating and rotor temperature rise too large and so on. In this paper, in order to determine the influence of the current harmonics on the motor performance, different harmonic currents were injected into the motor armature. Firstly, in order to study the influence of the current harmonic on the motor magnetic field, a novel decoupling method of the motor magnetic field was proposed. On this basis, the difference of harmonic content in an air gap magnetic field was studied, and the influence of a harmonic current on the air gap flux density was obtained. Secondly, by comparing the fluctuation of the motor torque in the fundamental and different harmonic currents, the influence of harmonic on a motor torque ripple was determined. Then, the influence of different current harmonics on the eddy current loss of the motor was compared and analyzed, and the influence of the drive harmonic on the eddy current loss was obtained. Finally, by using a finite element method (FEM), the motor temperature distribution with different harmonics was obtained.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 5.

Tytuł:: The least eigenvalue of the graphs whose complements are connected and have pendent paths
Autorzy:: Wang, C.
Yu, G.
Sun, W.
Cao, J.
Tematy:: graph
complement
pendent path
adjacency matrix
least eigenvalue; Pokaż więcej
Wydawca:: Społeczna Akademia Nauk w Łodzi. Polskie Towarzystwo Sieci Neuronowych
Powiązania:: https://bibliotekanauki.pl/articles/91753.pdf Link otwiera się w nowym oknie
Opis:: The adjacency matrix of a graph is a matrix which represents adjacent relation between the vertices of the graph. Its minimum eigenvalue is defined as the least eigenvalue of the graph. Let Gn be the set of the graphs of order n, whose complements are connected and have pendent paths. This paper investigates the least eigenvalue of the graphs and characterizes the unique graph which has the minimum least eigenvalue in Gn.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 6.

Tytuł:: Polarization dependence of patterning effects in quantum well semiconductor optical amplifier-based wavelength conversion
Autorzy:: Qin, C
Shen, W
Zhao, J.
Yu, H.
Xu, E
Tematy:: semiconductor optical amplifiers
polarization
patterning effect; Pokaż więcej
Wydawca:: Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Powiązania:: https://bibliotekanauki.pl/articles/173469.pdf Link otwiera się w nowym oknie
Opis:: In this paper, polarization dependence of patterning effects in quantum well semiconductor optical amplifier-based wavelength conversion is experimentally and theoretically investigated. The carrier and photon density rate equations are numerically solved by using the time-domain traveling wave model. The material gain calculation, including the strain effect in the active layer, is based on the k·p method. By comparing experimental and computational results, it is demonstrated that the polarization of the injection signal has a significant influence on the gain recovery time of quantum well semiconductor optical amplifier. Under the cross-polarized signals injection, the output signals suffer the weakest and strongest patterning effects both for unstrained and tensile strained quantum well semiconductor optical amplifiers.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 7.

Tytuł:: Strengthening and toughening mechanisms for polypropylene/Glass fiber composite foams under three-phase coexistence
Mechanizmy wzmacniające i utwardzające pianki kompozytowe polipropylen/włókno szklane w warunkach współistnienia trzech faz
Autorzy:: Gong, W.
Yu, J.
Fu, H.
Zhang, C.
He, L.
Tematy:: polypropylene
composite
foam
mechanical properties
polipropylen
kompozyt
pianka
właściwości mechaniczne; Pokaż więcej
Wydawca:: Sieć Badawcza Łukasiewicz - Instytut Chemii Przemysłowej
Powiązania:: https://bibliotekanauki.pl/articles/947491.pdf Link otwiera się w nowym oknie
Opis:: Composite foams were obtained through a two-step molding process in an injection molding machine. Gas phase was introduced into the mixture of molten polypropylene (PP) and solid glass fiber (GF). The interfacial behavior was investigated, and the strengthening and toughening mechanisms for PP/GF composites under three-phase coexistence were discussed. The incorporation of gas phase significantly increased the tensile strength by 112 % and impact toughness by 105 % in comparison to its unfoamed counterpart. The resulting mechanical properties of the PP/GF composite foams were found to depend considerably on the coexistence state of solid (GF) and gas (cells) phases and the cell structure of the foams.
Pianki kompozytowe otrzymano w dwustopniowym procesie formowania wtryskowego. Fazę gazową wprowadzano do mieszaniny stopionego polipropylenu (PP) ze stałymi włóknami szklanymi (GF). Badano właściwości mechaniczne otrzymanych pianek PP/GF oraz omówiono mechanizmy powodujące wzmacnianie i utwardzanie tych pianek w warunkach współistnienia trzech faz. Zaobserwowano, że wprowadzenie fazy gazowej znacznie zwiększa wytrzymałość na rozciąganie (o 112 %) i udarność pianki (o 105 %) w porównaniu z wartościami otrzymanymi w przypadku jej niespienionego odpowiednika. Stwierdzono, że właściwości mechaniczne pianek kompozytowych PP/GF w znacznym stopniu zależą od stanu współistnienia fazy stałej (GF) i gazowej (pory) oraz struktury komórkowej pianki.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 8.

Tytuł:: Use of nanofiltration membranes to concentrate and recover leached aluminum from acidified water treatment sludge
Autorzy:: Cheng, W. P.
Chen, P. H.
Tian, D. R.
Yu, R. F.
Fu, C. H.
Tematy:: water purification
nanofiltration
acidic solutions
leaching
roztwory kwaśne
oczyszczanie wody
nanofiltracja
ługowanie
glin; Pokaż więcej
Wydawca:: Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Powiązania:: https://bibliotekanauki.pl/articles/208030.pdf Link otwiera się w nowym oknie
Opis:: The recovery of aluminum from water purification sludge is usually performed by making the solution acidic or basic. However, for economic reasons and reasons of safety, excessive doses of acid or base should not be utilized. Accordingly, the aluminum concentration in the leached solution is typically limited, thus the recovered aluminum cannot be directly reused as a coagulant. A nanofiltration (NF) membrane can be used in the acidic solution to concentrate high-valence metal ions. There-fore, in this work, H₂SO₄ was utilized to leach Al³⁺ ions from water purification sludge. Then, the Al³⁺ ion solution was concentrated using a low-price NF membrane. The effect of natural organic matter on the Al³⁺ ion concentrating efficiency in the filtration process has been elucidated. Experimental results reveal that Al³⁺ ions were effectively prevented from passing through the NF membrane, enabling a highly concentrated aluminum solution to be obtained. However, the presence of organic compounds may reduce the efficiency of the concentration of Al³⁺ ions in the solution.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 9.

Tytuł:: Comparison of float-sink and progressive release flotation of ground products of coal middlings
Autorzy:: Xie, W.
He, Y.
Luo, C.
Zhang, X.
Li, H.
Yu, J.
Wang, H.
Shi, F.
Tematy:: coal middlings
float-sink
progressive release flotation
XPS
EDX; Pokaż więcej
Wydawca:: Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Powiązania:: https://bibliotekanauki.pl/articles/109500.pdf Link otwiera się w nowym oknie
Opis:: An additional recovery of coking coal middlings can be utilized for increasing of the concentrate yield of coking coal. A combined flow sheet of comminution and flotation can realize this target. To investigate the effect of grinding process on further flotation of ground products, progressive release flotation tests were used to compare with the float-sink tests, which were regarded as a criterion. Coal middlings were ground by wet-milling with iron balls to <0.5 mm. Curves of ash vs. cumulative yields of sized products indicated that the concentrate yield of coal separated by progressive release flotation was lower than that of coal benefited by the float-sink test, with the same ash for four size fractions (0.5-0.25 mm, 0.25-0.125 mm, 0.125-0.074 mm and <0.074 mm). Distributions of elements conducted by energy disperse spectroscopy (EDX) showed that associated kaolinite was liberated and exposed on the surface. It led to the shift of local surface property from hydrophobicity to hydrophilicity. Meanwhile, analyses of chemical property performed by an X-Ray photoelectron spectrometer (XPS) depicted that the hydrophilic mineral FeOOH, which generated in the grinding process, was adsorbed on the coal surface. Flotation of the ground products were worsened due to the increase of hydrophilicity of the coal surface.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 10.

Tytuł:: Bulk and local properties of DyRhSn
Autorzy:: Verbovytsky, Yu.
Sebastian, C. P.
Pacyna, A. W.
Łątka, Kazimierz
Pöttgen, R.
Przewoźnik, J.
Gurgul, J.
Dostawca treści:: Repozytorium Uniwersytetu Jagiellońskiego

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