Wyniki wyszukiwania - Biblioteka Nauki

1

Thermal Performance Assessment of Heat Resistant Fabrics Based on a New Thermal Wave Model of Skin Heat Transfer

100%

Zhu F. , Zhang W. , Song G.

International Journal of Occupational Safety and Ergonomics

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2006

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tom Vol. 12, No. 1

43--51

EN

A thermal wave skin model incorporating surface heat flux from a skin simulant sensor is developed to characterize the thermal performance of heat resistant fabrics covering the skin simulant sensor. Comparisons of time to 2nd-degree skin burn and temperature elevation of skin beneath a layer of fabric between the Pennes’ equation and the newly developed thermal wave skin model are performed in this research. Results of tolerance time from the Stoll criterion method are also compared with those from 2 skin models in a thermal protective performance calorimeter. It is concluded that the thermal properties of heat resistant fabrics can be characterized more precisely than previously.

2

Determination of bovine serum albumin in the forum of its triple complex with Fe(bph)(phen)SO4-myristylpyridinium bromide by resonance light-scattering technique

100%

Li L. , Song G. , Fang G.

Chemia Analityczna

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2009

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tom Vol. 54, No. 1

99-107

EN

A mixed complex Fe(bpy)(phen)²⁺ was synthesized and resonance light-scattering (RLS) characteristics of a triple complex Fe(bpy)(phen)SO₄-Myristylpyridinium bromide-bovine serum albumin were studied. When albumin was added, Fe(bpy)(phen)^{2+^-1.}

PL

Otrzymano mieszany kompleks Fe(bpy)(phen) )²⁺ i zbadano charakterystykę rezonansowego rozpraszania światła (RLS) przez potrójny kompleks Fe(bpy(phen)SO_{4_{2+ ulegał agregacji na powierzchni jej cząsteczek. W rezultacie sygnały RLS ulegały wzmocnieniu przy 400 nm i 470 nm. Intensywność sygnału RLS była proporcjonalna do stężenia albuminy wołowej. Stwierdzono, że obecność jonu mirystylopirydyniowego zwiększała czułość układu. Granicę oznaczalności określono na 0,02 mg L^-1.}}

3

Numerical Simulations of Heat and Moisture Transport in Thermal Protective Clothing Under Flash Fire Conditions

100%

Song G. , Chitrphiromsri P. , Ding D.

International Journal of Occupational Safety and Ergonomics

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2008

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tom Vol. 14, No. 1

89--106

EN

A numerical model of heat and moisture transport in thermal protective clothing during exposure to a flash fire was introduced. The model was developed with the assumption that textiles are treated as porous media. The numerical model predictions were compared with experimental data from different fabric systems and configurations. Additionally, with the introduction of a skin model, the parameters that affect the performance of thermal protective clothing were investigated.

4

Stress corrosion cracking of magnesium

88%

Winzer N. , Song G. , Atrens A. , Dietzel W. , Kainer K. U.

Advances in Materials Science

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2007

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tom Vol. 7, nr 1(11)

83-92

EN

The increased use of Mg-alloys for stressed automotive components has created a demand for a better mechanistic under-standing of the environmental and mechanical influences contributing to Transgranular Stress Corrosion Cracking (TGSCC). TGSCC is the inherent mode of failure for Mg alloys exposed to aqueous environments below their yield stress. It is gener-ally accepted that the predominant mechanism(s) for TGSCC is a type of Hydrogen Assisted Cracking (HAC); however, the specific nature of this mechanism(s) is equivocal. The most commonly proposed mechanism is Delayed Hydride Cracking (DHC). This work investigates its tenability by comparing experimental measurements of the stress corrosion crack velocity, Vc with predictions based on a numerical model for DHC. The measured velocity was in the range of 7x10-10 m/s to 5x10-9 m/s. The initial prediction of the DHC model is 5x10-7 m/s. An investigation into the sensitivity of the model to input parameters is currently underway.

5

Epidemiological evidence of the effects of environmental pollution on male reproductive health in an electronic waste-recycling Town

88%

Du H. , Yu M. , Sun J. , Song G. , Li Y.

Polish Journal of Environmental Studies

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2016

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tom 25

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nr 4

EN

In recent years have seen increasing evidence linking occupational and environmental exposure to toxic pollutants with human male reproductive disorders. The aim of this study was to collect epidemiological information on male reproductive health to explore the effects of electronic waste (e-waste) environmental pollution on male genital health in Wenling, one of the world’s biggest e-waste recycling centers. We collected clinic information from 2001 to 2012 in Wenling covering male reproductive diseases, including prostatitis, epididymitis, orchitis, urinary tract infections, cystospermitis, impotence, condyloma accuminatum, syphilis, gonorrhea, varicocele, genital herpes, prostatic carcinoma, etc. The morbidity of male reproductive diseases in Wenling was higher than in the control area – especially those diseases that could be influenced by environmental factors. Male reproductive health may be threatened by e-waste pollution in Wenling, and this could influence local population diathesis.

6

A preliminary investigation of boundary layer effects on daytime atmospheric CO2 concentrations at a mountaintop location in the Rocky Mountains

75%

De Wekker S. F. J. , Ameen A. , Song G. , Stephens B. B. , Hallar A. G. , McCubbin I. B.

Acta Geophysica

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2009

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tom Vol. 57, no. 4

904-922

EN

Observations of CO2 concentration at a mountaintop in the Colorado Rockies in summer show a large diurnal variability with minimum CO2 concentrations found between 10:00 and 18:00 MST. Simulations are performed with a mesoscale model to examine the effects of atmospheric structure and large-scale flows on the diurnal variability. In the simulations initialized without large-scale winds, the CO2 minimum occurs earlier compared to the observations. Upslope flows play an important role in the presence of this early (pre-noon) minimum while the timing and magnitude of the minimum depend only weakly on the temperature structure. An increase in large-scale flow has a noticeable impact on the diurnal variability with a more gradual decrease in daytime CO2 concentration, similar to summer-averaged observations. From the idealized simulations and a case study, it is concluded that multi-scale flows and their interactions have a large influence on the observed diurnal variability.

7

Indexing accuracy reliability sensitivity analysis of power tool tur ret

75%

Changyou L. , Wei W. , Yimin Z. , Song G. , Zhenyuan L. , Changshuai Q.

Eksploatacja i Niezawodność

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2015

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tom Vol. 17, no. 1

27--34

EN

Power tool turret (PTT) is one of the most key parts of CNC (Computer Numerical Control) turning center and CNC turning and milling machining center. Therefore, it is very important for improving these two types of machine tools’ reliability to explore the indexing accuracy reliability of PTT and its sensitivity. To analyze the indexing accuracy reliability sensitivity of PTT, the angular displacement error of the rotating gear disc is discussed based on the measurement uncertainty theory. The tooth thickness wear process of the fixed gear disc, the rotating gear disc and the lock gear disc are modeled using Gamma process of which the parameters are estimated. The indexing error of PTT is formulated by employing the BP neural network and validated by the experiment data. Then, the indexing accuracy reliability equation of PTT is derived and its sensitivity to the mean and the standard deviation of random variables or wear stochastic processes is analyzed. The results show that the presented indexing accuracy reliability and its sensitivity of PTT are effective.

PL

Głowica narzędziowa z napędzanymi narzędziami (ang. power tool turret, PTT) stanowi jedną z kluczowych części sterowanych komputerowo tokarskich i tokarsko-frezarskich centrów obróbczych CNC. Dlatego też dla poprawy niezawodności tych dwóch rodzajów obrabiarek istotne jest badanie niezawodności w zakresie dokładności indeksowania głowicy PTT oraz wrażliwości wskaźnika niezawodności. Dla celów analizy wrażliwości wskaźnika niezawodności w zakresie dokładności indeksowania głowicy PTT, omówiono błąd przesunięcia kątowego obrotowej tarczy narzędziowej w oparciu o teorię niepewności pomiaru. Proces zużycia ściernego zębów tarcz narzędziowych: stałej, obrotowej oraz uchwytowej, zamodelowano przy użyciu procesu Gamma o szacunkowych parametrach. Błąd indeksowania PTT obliczono przy zastosowaniu sieci neuronowej BP i zweryfikowano na podstawie danych doświadczalnych. Następnie wyprowadzono równanie niezawodności w zakresie dokładności indeksowania PTT oraz przeprowadzono analizę wrażliwości wskaźnika niezawodności na średnią i odchylenie standardowe zmiennych losowych lub procesów stochastycznych zużycia. Wyniki pokazały skuteczność omawianej analizy niezawodności w zakresie dokładności indeksowania PTT oraz wrażliwości wskaźnika niezawodności.

8

17beta-Estradiol promotes cell proliferation in rat osteoarthritis model chondrocytes via PI3K/Akt pathway

75%

Huang J. , Xia C. , Zheng X. , Yi T. , Wang X. , Song G. , Zhang B.

Cellular and Molecular Biology Letters

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2011

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tom 16

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nr 4

EN

Osteoarthritis (OA) is the most common cause of musculoskeletal pain and disability. The importance of chondrocytes in the pathogenesis of OA is unequivocal. 17β-estradiol (E2) has a potential protective effect against OA. However, the mechanism of E2 in OA chondrocytes remains unclear. In this study, we investigated the regulative effect of E2 on cell growth and the relationship between E2 and the PI3K/Akt pathway in rat OA model chondrocytes (pretreated with interleukin-1β). We found that E2 induced chondrocyte proliferation, and increased the expression level of Akt simultaneously, especially the expression level of P-Akt. Furthermore, the inhibition of P-Akt could block chondrocyte proliferation induced by E2. These results suggest that PI3K/Akt activation induced by E2 may be an important factor in the mechanism of E2 in cell proliferation in rat OA model chondrocytes, and help further understanding the role of E2 in OA progression.

9

Reduction of Thermal Conductivity Through Complex Microstructure by Dispersion of Carbon Nanofiber in p-Type Bi0.5Sb1.5Te3 Alloys

75%

Sharief P. , Madavali B. , Sohn Y. , Han J. H. , Song G. , Hong S. J.

Archives of Metallurgy and Materials

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2021

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tom Vol. 66, iss. 3

803--808

EN

The influence of nano dispersion on the thermoelectric properties of Bi2Te3 was actively investigating to wide-spread thermoelectric applications. Herein this report, we have systematically controlled the microstructure of Bi0.5Sb1.5Te3 (BST) alloys through the incorporation of carbon nanofiber (CNF), and studied their effect on thermoelectric properties, and mechanical properties. The BST/x-CNF (x-0, 0.05, 0.1, 0.2 wt.%) composites powder was fabricated using high energy ball milling, and subsequently consolidated the powder using spark plasma sintering. The identification of CNF in bulk composites was analyzed in Raman spectroscopy and corresponding CNF peaks were recognized. The BST matrix grain size was greatly reduced with CNF dispersion and consistently decreased along CNF percentage. The electrical conductivity was reduced and Seebeck coefficient varied in small-scale by embedding CNF. The thermal conductivity was progressively diminished, obtained lattice thermal conductivity was lowest compared to bare sample due to induced phonon scattering at interfaces of secondary phases as well as highly dense fine grain boundaries. The peak ZT of 0.95 achieved for 0.1 wt.% dispersed BST/CNF composites. The Vickers hardness value of 101.8 Hv was obtained for the BST/CNF composites.

10

Preliminary results of spatial distribution of uranium and thorium in soil profi les near a uranium industrial site, Guangdong province, China

63%

Wang J. , Liu J. , Chen Y. , Song G. , Chen D. , Xiao T. , Li H. , Wang C. , Jiang F.

Nukleonika

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2016

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tom Vol. 61, No. 3

367--371

EN

Four soil profiles were collected from locations with different distances (5, 50, 250 and 1000 m) from a uranium mill tailings dam, Guangdong province, China, to investigate the pollution status of the soil in mining/ milling-related areas based on the contents of uranium (U) and thorium (Th), thus to understand the impacts of uranium industrial activities to the surroundings. The U and Th concentrations were determined by inductively coupled plasma mass spectrometry (ICP-MS) after conventional HF-HNO3-HClO4 digestion procedures. The results indicate that the soils within 50 m from uranium tailing were severely contaminated; those in 250 and 1000 m soil samples were observed to be with local background level even though these in 250 m had slightly higher U/Th ratios. Uranium concentrations varied from 5.50 ± 0.27 to 160.55 ± 8.03 mg/kg, with maximum values recorded in an intermediate layer of the 5-m distance soil profile. In comparison, the concentration of Th ranged from 6.02 ± 0.30 to 84.71 ± 4.24 mg/kg, with maximum values observed in the top layer of the 1000-m distance soil profile. The U/Th ratio varied from 0.15 to 11.99 compared with 0.20, 0.22 and 0.26 of the average for Guangdong province, national China and the world, respectively. The mean U/Th of four soil profiles showed a reduction with distance from the uranium mill tailing dam, suggesting the relatively large magnitude of uranium elevation in soils within limited distances.

11

Metastasis of human gastric adenocarcinoma partly depends on phosphoinositide-specific phospholipase gamma1 expression

63%

Zhuang L. , Zhang B. , Zeng G. , Dai L. , Qian H. , Hu T. , Song G. , Zhang B. , Xia C.

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nr 3

12

Toxic effects of anatase titanium dioxide nanoparticles on spermatogenesis and testicles in male mice

63%

Song G. , Lin L. , Liu L. , Wang K. , Ding Y. , Niu Q. , Mu L. , Wang H. , Shen H. , Guo S.

Polish Journal of Environmental Studies

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2017

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tom 26

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nr 6

EN

Anatase TiO₂ nanoparticles (NPs) are widely used in food products, capsules, toothpaste, and so on, so the kinds of NPs directly get in touch with human bodies. The potential effect of this kind of material on reproduction must be considered with the increase in infertility. Sixty ICR male mice were intragastrically treated with dosages of 0, 10, 50, and 100 mg kg⁻¹ body weight (BW) anatase TiO₂ NPs to investigate the male reproductive toxicity of the NPs. Sperm quality, morphological changes in mice testes, and oxidative damage indexes were investigated in this study. Results showed that anatase TiO₂ NPs could lead to sperm malformation and increased rate of sperm cell micronucleus. These NPs also reduced the germ cell number and led to spherospermia, interstitial glands vacuole, malalignment, and vacuolization of spermatogenic cells in mice testes. Testicular cells accumulated reactive oxygen species when the mice were intragastrically administrated with TiO₂ NPs. Superoxide dismutase activity decreased, and the malondialdehyde content increased in the TiO₂ NP-treated groups. Anatase TiO₂ NPs exerted potential toxic effects on male reproduction, so the widespread application of this kind of NP in food products needs to be regulated.