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Discussion　on　the　Network　Method　for　Calculating　Radiant　Interchange　Within　an　Enclosure

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Journal of Thermal Science 1994年第2期3卷 130-135页

作者： h.J. Kang W.Q. Tao(School of Energy and Power Engineering, Xi’an Jiaotong University, Xi’an, Shaanxi 710049, China) 1. School of Energy and Power Engineering Xi’an Jiaotong University 710049 Xi’an Shaanxi China

In this paper the △- Y transformation of a linear electric circuit is introduced to simplify the computation of net radiant heat exchange on a surface of an enclosure with three surfaces. The illustration of the transformation is given by solving six problems taken from the textbooks. Some discussion concerning the possibility of extending the transformation method to enclosures with more than three surfaces, and the condition for applying the network method are also presented.

关键词： radiative heat transfer network method enclosure.

EFFECTS OF MODIFICATION OF ThE CARBIDE ChARACTERISTICS ThROUGh GRAIN BOUNDARY SERRATION ON CREEP-FATIGUE LIFE IN AUSTENITIC STAINLESS STEELS

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Acta Metallurgica Sinica(English Letters) 2004年第5期17卷 632-638页

作者： K.J.Kim h.U.hong K.S.Min S.W.Nam Dept. of Materials Science and Engineering Korea Advanced Institute of Science and Technology 373-1 Guseong-dong Yuseong-gu Deajeon 305-701 KoreaPosco Technical Research Laboratory #1 Koedong-dong Nam-gu Pohang 790-300 KoreaProcess Solution Development Team 1 LCD R&D Center AMLCD Division Device Solution Network Samsung Electronics Co. LTD.San 24 Nongseo-ri Giheung-eup Yongin Gyeonggi-do 449-771 KoreaDept. of Materials Science and Engineering Korea Advanced Institute of Science and Technology 373-1 Guseong-dong Yuseong-gu Deajeon 305-701 Korea

Modification of the carbide characteristics through the grain boundary serration is investigated, using an AISI 316 and 304 stainless steels. In both steels, triangular carbides were observed at straight grain boundaries while planar carbides were observed at the serrated grain boundaries. The serrated grain boundary energy is observed to be much lower than that of the straight one. Therefore, the carbide morphology is found to be changed from triangular to planar along the serrated boundary to reduce the interfacial energy between the carbide and the matrix. The creep-fatigue properties of these steels at 873K have been investigated. The creep-fatigue life of the sample with planar carbide at the serrated grain boundary was found to be much longer than that with triangular carbide at the straight one. These results imply that the planar carbides with lower interfacial energy have higher cavitation resistance, resulting in the retardation of cavity nucleation and growth to increase creep-fatigue life.

关键词： cavity nucleation factor grain boundary serration carbide morphology austenitic stainless steel grain boundary cavitation

Nitrous Oxide Emission by Agricultural Soils: A Review of Spatial and Temporal Variability for Mitigation

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Pedosphere 2012年第4期22卷 426-433页

作者： C. hNAULT A. GROSSEL B. MARY M. ROUSSEL J. LONARD INRA UR 272 Science du Sol Centre de Recherches d'Orléans CS 40001 Ardon 45075 Orléans cedex 2 (France) INRA-Université de Bourgogne UMR 1229 Microbiologie du sol et de l'Environnement 17 rue Sully BP 86510 21065 Dijon cedex (France) INRA US 1158 Agro-Impact Po le du Griffon 180 rue Pierre-Gilles de Gennes 02000 Barenton-Bugny (France)

This short review deals with soils as an important source of the greenhouse gas N2O. The production and consumption of N2O in soils mainly involve biotic processes: the anaerobic process of denitrification and the aerobic process of nitrification. The factors that significantly influence agricultural N2O emissions mainly concern the agricultural practices (N application rate, crop type, fertilizer type) and soil conditions (soil moisture, soil organic C content, soil ph and texture). Large variability of N2O fluxes is known to occur both at different spatial and temporal scales. Currently new techniques could help to improve the capture of the spatial variability. Continuous measurement systems with automatic chambers could also help to capture temporal variability and consequently to improve quantification of N2O emissions by soils. Some attempts for mitigating soil N2O emissions, either by modifying agricultural practices or by managing soil microbial functioning taking into account the origin of the soil N2O emission variability, are reviewed.

关键词： agricultural practices fertilization greenhouse gas N2O fluxes soil-atmosphere interface

A hybrid Classification and Identification of Pneumonia Using African Buffalo Optimization and CNN from Chest X-Ray Images

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Computer Modeling in Engineering & Sciences 2024年第3期138卷 2497-2517页

作者： Nasser Alalwan Ahmed I.Taloba Amr Abozeid Ahmed Ibrahim Alzahrani Ali h.Al-Bayatti Computer Science Department Community CollegeKing Saud UniversityRiyadh11437Saudi Arabia Information System Department Faculty of Computers and InformationAssiut UniversityAssiutEgypt Mathematics Department Faculty of ScienceAl-Azhar UniversityCairoEgypt Cyber Technology Institute(CTI) De Montfort UniversityLeicesterUK

An illness known as pneumonia causes inflammation in the *** there is so much information available fromvarious X-ray images,diagnosing pneumonia has typically proven *** improve image quality and speed up the diagnosis of pneumonia,numerous approaches have been *** date,several methods have been employed to identify *** Convolutional Neural Network(CNN)has achieved outstanding success in identifying and diagnosing diseases in the fields of medicine and ***,these methods are complex,inefficient,and imprecise to analyze a big number of *** this paper,a new hybrid method for the automatic classification and identification of Pneumonia from chest X-ray images is *** proposed method(ABOCNN)utilized theAfrican BuffaloOptimization(ABO)algorithmto enhanceCNNperformance and *** Weinmed filter is employed for pre-processing to eliminate unwanted noises from chest X-ray images,followed by feature extraction using the Grey Level Co-Occurrence Matrix(GLCM)*** features are then selected from the dataset using the ABO algorithm,and ultimately,high-performance deep learning using the CNN approach is introduced for the classification and identification of *** results on various datasets showed that,when contrasted to other approaches,the ABO-CNN outperforms them all for the classification *** proposed method exhibits superior values like 96.95%,88%,86%,and 86%for accuracy,precision,recall,and F1-score,respectively.

关键词： African buffalo optimization convolutional neural network pneumonia X-ray

3D Printing of Polylactic Acid Bioplastic–Carbon Fibres and Twisted Kevlar Composites Through Coextrusion Using Fused Deposition Modeling

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Journal of Renewable Materials 2020年第12期8卷 1671-1680页

作者： J.Y.Tey W.h.Yeo Y.J.King W.O.Ding Department of Mechanical and Material Engineering Lee Kong Chian Faculty of Engineering and ScienceUniversiti Tunku Abdul RahmanJalan Sungai LongBandar Sungai LongCheras43000 KajangSelangorMalaysia

Polylactic acid(PLA)bioplastic is a common material used in Fused Deposition Modeling(FDM)3D *** is biodegradable and environmentally friendly biopolymer which made out of ***,it exhibits weak mechanical properties which reduced its usability as a functional prototype in a real-world *** the present study,two PLA composites are created through coextruded with 3K carbon fibres and twisted Kevlar string(as core fibre)to form a fibre reinforced parts(FRP).The mechanical strength of printed parts was examined using ASTM D638 standard with a strain rate of 1 mm/*** has been demonstrated that the FRPs coextruded with 3K carbon fibres had achieved significant improvement in Young’s modulus(+180.6%,9.205 GPa),ultimate tensile strength(+175.3%,103 MPa)and maximum tensile strain(+21.6%,1.833%).Although the Young’s modulus of Kevlar FRP was found to be similar to as compared to unreinforced PLA(~3.29 GPa),it has gained significant increment in terms of maximum tensile strain(+179.7%,104.64 MPa),and maximum tensile strain(+257%,5.384%).Thus,this study revealed two unique composite materials,in which the 3K carbon FRP can offer stiff and high strength structure while Kevlar FRP offers similar strength but at a higher elasticity.

关键词： 3D printing Kevlar fibre 3K carbon fibre coextruded reinforced plastic polylactic acid bioplastic

TRANSMISSION ELECTRON MICROSCOPY INVESTIGATIONS OF LOW-PRESSURE CVD GROWTh AND STRAIN RELAXATION OF Ge ISLANDS ON Si(110)

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Acta Metallurgica Sinica(English Letters) 2005年第3期18卷 427-432页

作者： E.Spiecker L.Zhang h.M.Lu W.Jaeger L.Vescan MicroanalysisofMaterials FacultyofEngineeringChrisfian-Albrechts-UniversityKielKaiserstraβe224143KielGermany InstituteofThinFilmsandInterfaces ResearchCenterJiilichGmbH52425JiilichGermany

Shapes, dimensions, arrangements and the microstructure of self-assembled island s fabricated by low-pressure chemical vapour deposition (LPCVD) of Ge at 700℃ o nto Si(110) substrates have been investigated for different nominal Ge coverage by transmission electron microscopy (TEM) of plan-view and cross-section specime ns and have been compared with photoluminescence (PL) measurements of Si-capped layer samples. The transition from the 2-dimensional layer to the 3-dimensional island growth mode takes place for a Ge deposition of nominally less than 2 mono layers. Upon this transition, many coherent islands and few larger islands with extended defects are observed. The coherent islands possess a dome-like shape an d lateral sizes up to 130nm. Photoluminescence spectra show island-related peaks whose energy positions are shifted towards lower energy with higher Ge coverage .

关键词： Si-Ge heteroepitaxy surface transmission electron microscopy Nanostructure

Numerical investigation of a double-junction a:Si Ge thin-film solar cell including the multi-trench region

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Journal of Semiconductors 2015年第6期36卷 53-57页

作者： K.Kacha F.Djeffal h.Ferhati D.Arar M.Meguellati LEA Department of Electronics University of Batna LEPCM University of Batna

We present a new approach based on the multi-trench technique to improve the electrical performances, which are the fill factor and the electrical efficiency. The key idea behind this approach is to introduce a new multi-trench region in the intrinsic layer, in order to modulate the total resistance of the solar cell. Based on 2- D numerical investigation and optimization of amorphous SiGe double-junction （a-Si：h/a-SiGe：h） thin film solar cells, in the present paper numerical models of electrical and optical parameters are developed to explain the impact of the multi-trench technique on the improvement of the double-junction solar cell electrical behavior for high performance photovoltaic applications. In this context, electrical characteristics of the proposed design are analyzed and compared with conventional amorphous silicon double-junction thin-film solar cells.

关键词： amorphous efficiency SiGe thin-film solar cell multi-trench

GENETIC CONSEQUENCES OF INTRODUCED Gouramy helostoma Temminckii (Pisces: helostomatidae) IN BRUNEI'S WETLAND

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湿地科学 2003年第1期1卷 51-56页

作者： h.S.Zohrah P.h.C.Fauzani C. S. Jen O. Norsuzieyanti

Kissing gouramy (helostoma temminckii) was introduced into Tasek Merimbun in the 1980's. We studied their genetic profile using allozyme electrophoresis and found that all loci were monomorphic. The loss of heterozygotes may suggest that the gouramy are inbreds. They must have reproduced by repeated sib-mating over the years. The severe drought in Tasek Merimbun may have aggravated the genetic erosion further. The genetic variability of kissing gouramy in terms of % polymorphic loci, mean number of alleles per loci and observed heterozygosity level were lower than cyprinids in the same lake and kissing gouramy from the wild. We also note that kissing gouramy is a fast grower and may threaten the livelihood of indigenous fishes in the lake.

关键词： Kissing gouramy introduced allozyme electrophoresis

Robust Sliding Mode Control Using Adaptive Switching Gain for Induction Motors

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International Journal of Automation and computing 2013年第4期10卷 303-311页

作者： K. Jamoussi L. Chrifi-Alaoui h. Benderradji A. El hajjaji M. Ouali Laboratory Computer and Embedded Systems National Engineering School University of Sfax Laboratory of Innovative Technology University of Picardie Jules Verne University of M'sila Electrical Engineering Department Laboratory of Modeling Information and Systems University of Picardie Jules Verne France

A robust sliding mode approach combined with a field oriented control （FOC） for induction motor （IM） speed control is presented. The proposed sliding mode control （SMC） design uses an adaptive switching gain and an integrator. This approach guarantees the same robustness and dynamic performance of traditional SMC algorithms. And at the same time, it attenuates the chattering phenomenon, which is the main drawback in actual implementation of this technique. This approach is insensitive to uncertainties and permits to decrease the requirement for the bound of these uncertainties. The stability and robustness of the closed- loop system are proven analytically using the Lyapunov synthesis approach. The proposed method attenuates the effect of both uncertainties and external disturbances. Experimental results are presented to validate the effectiveness and the good performance of the developed method.

关键词： Sliding mode control field oriented control (FOC) practical validation switching gain induction motor.