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International Journal of Mining Science and Technology 2018年第5期28卷 807-811页

作者： faham tahmasebinia Chengguo Zhang Ismet Canbulat Onur Vardar Serkan Saydam School of Minerals and Energy Resources Engineering University of New South Wales

Designing reliable yielding support system to mitigate the effect of the kinetic energy in burst-prone conditions in mining and tunneling excavations is one of the challenges for geotechnical engineers. A combination of the support elements can be used to increase rock strength and minimise the displacement of unstable rock mass. It is important to understand how the support system works to ensure the stability of underground excavations. Cable bolts have been commonly used as an effective underground support system and an element of reinforcement to improve rock stability. Cable bolts are usually considered to be subjected to static loads under relatively low stress environments, however, in burst-prone conditions, they might be subjected to dynamic loads. Cable bolts as well as other support elements are used in burst-prone conditions to absorb the kinetic energy of the removed rock to avoid sudden and violent failures. This paper develops numerical and a novel analytical simulation technique for cable bolts to assess their structural behaviour under static and dynamic loading conditions. The numerical and analytical models are then validated against experimental observations reported in the literature, which demonstrates the reliability of the proposed models.

关键词： Cable bolts Yielding support Coal burst Shear dynamic loading

Computing the damage and fracture energy in a coal mass based on joint density

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International Journal of Mining Science and Technology 2018年第5期28卷 813-817页

作者： faham tahmasebinia Chengguo Zhang Ismet Canbulat Onur Vardar Serkan Saydam School of Minerals and Energy Resources Engineering University of New South Wales

Coal joints and cleats are geological discontinuities that are the most important factors that affect the mechanical responses of a coal mass under stress. The joint and coal mass interaction and the mode of failure dominate the mechanical behaviour of jointed coal masses, and therefore the stability of coal excavations. The shear or mixed shear/tensile failure changes to tensile failure by increasing the confining pressure, discontinuity length and angle. This paper extends a thermodynamic approach to constitutive modelling of the coal mass by developing local and non-local damage models based on the joint and cleat density and the dip angle. A consistent and rigorous statistical framework is constructed, which incorporates both local and non-local features into the constitutive modelling. This is an important consideration in developing damage constitutive models based on the trajectory of the failure surfaces in a coal mass.An equation is derived to calculate the fracture energy which is a function of the joint density either in a single direction or crossed conditions.

关键词： Joint density Dissipated energy Coal mass Damage model

Assessment of energy release mechanisms contributing to coal burst

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International Journal of Mining Science and Technology 2017年第1期27卷 43-47页

作者： Zhang Chengguo Canbulat Ismet tahmasebinia faham Hebblewhite Bruce School of Mining Engineering UNSW Sydney 2052Australia

Coal burst is a dynamic release of energy within the rock(or coal) mass leading to high velocity expulsion of the broken/failed material into mine openings. This phenomenon has been recognised as one of the most catastrophic failures associated with the coal mining industry, which can often lead to injuries and fatalities of miners as well as significant production losses. This paper aims to examine the mechanisms contributing to coal burst occurrence, with an emphasis on the energy release concept. In this study, a numerical modelling study has been conducted to evaluate the roles and contributions of difference energy components. The energy analysis presented in this paper can help to improve the understanding of energy release mechanisms especially under Australian conditions.

关键词：能量释放释放机制煤爆评价动态释放煤炭开采生产损失数值模拟

Modified Cepstral Feature for Speech Anti-spoofing

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Journal of Donghua University(English Edition) 2023年第2期40卷 193-201页

作者：何明瑞 ZAIDI Syed faham Ali 田娩鑫单志勇江政儒徐珑婷 College of Information Science and Technology Donghua UniversityShanghai 200051China SPIC Jiangsu Offshore Wind Power Co. Ltd.Yancheng 224001China

The hidden danger of the automatic speaker verification(ASV)system is various spoofed speeches.These threats can be classified into two categories,namely logical access(LA)and physical access(PA).To improve identification capability of spoofed speech detection,this paper considers the research on features.Firstly,following the idea of modifying the constant-Q-based features,this work considered adding variance or mean to the constant-Q-based cepstral domain to obtain good performance.Secondly,linear frequency cepstral coefficients(LFCCs)performed comparably with constant-Q-based features.Finally,we proposed linear frequency variance-based cepstral coefficients(LVCCs)and linear frequency mean-based cepstral coefficients(LMCCs)for identification of speech spoofing.LVCCs and LMCCs could be attained by adding the frame variance or the mean to the log magnitude spectrum based on LFCC features.The proposed novel features were evaluated on ASVspoof 2019 datase.The experimental results show that compared with known hand-crafted features,LVCCs and LMCCs are more effective in resisting spoofed speech attack.

关键词： spoofed speech detection log magnitude spectrum linear frequency cepstral coefficient(LFCC) hand-crafted feature

Pepper plants growth, yield, photosynthetic pigments, and total phenols as affected by foliar application of potassium under different salinity irrigation water

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Agricultural Sciences 2012年第2期3卷 241-248页

作者： M. M. Hussein S. Y. El-faham A. K. Alva Food Technology Department National Research Centre Cairo Egypt United States Department of Agriculture-Agricultural Research Service (USDA-ARS) USA Water Relations and Irrigation Department National Research Centre Cairo Egypt

Irrigation with high salinity water influences plant growth, production of photosynthetic pigments and total phenols, leading to reduction in crop yield and quality. The objective of this study was to investigate the effects of potassium (K) foliar application in mitigating the negative effects of salt stress on pepper plants. A greenhouse experiment was conducted to investigate the effects of foliar application of potassium (K) on pepper plants grown with different salinity water irrigation (3000 and 6000 ppm as compared to tap water with salinity level of 300 ppm). Irrigation using high salinity water decreased plant height, biomass production, and fruit yield as compared to those of the plants irrigated by tap water. Photosynthetic pigments and total phenols increased in the former as compared to those of the latter plants. The most serious affect was for the plants under highest salinity irrigation (6000 ppm) as compared to that of the plants under moderate salinity irrigation (3000 ppm). Foliar application of potassium mono phosphate (KMP) at 200ppm concentration increased the plant growth, biomass production, and fruit yield. Chlorophyll_a content and total phenols increased significantly with foliar application of 100 ppm KMP. Further increase in foliar KMP concentration to 200 ppm had no significant benefits on photosynthetic pigments and total phenols content. This study demonstrated that foliar application of KMP, to some extent, mitigated the negative effects of high salinity water irrigation on pepper plant growth and fruit yield.

关键词： Diluted Sea Water Potassium Mono Phosphate Chlorophyll_a Chlorophyll_b Carotenoids Potassium Nutrition

Aminolysis of 1-(1-Hydroxybenzotriazolyl)-2,4-dinitrobenzene and 2-(1-Hydroxybenzotriazolyl)-5-nitropyridine

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Open Journal of Physical Chemistry 2012年第3期2卷 156-168页

作者： Sherine N. Khattab Mohamed A. H. Kharaba Amal El-Hawary Ayman El-faham Ezzat A. Hamed Department of Chemistry and Physics Faculty of Education Alexandria University Alexandria Egypt Department of Chemistry Faculty of Science Alexandria University Ibrahimia Egypt

The reaction 1-(1-hydroxybenzotriazolyl)-2,4-dinitrobenzene 1 and 2-(1-hydroxybenzotriazolyl)-5-nitro-pyridine 2 with amines undergoes amination followed by elimination of the 1-hydroxyl benzotriazolyl anion. The kinetic data for the reaction of 1 and 2 with Mo, CHA and An in MeOH and AN proceeded by uncatalysed mechanism in which the rate limiting step is the leaving group departure, whereas the reaction with Mo in toluene proceeded by uncatalysed mechanism in which the formation of the zwitterionic intermediate is the rate determining step. While the reactions of 1 with CHA and An and the reaction of 2 with CHA in toluene proceeded by SB mechanism in which the rate determining step is the proton transfer process. The reactions of 1 and 2 with Mo in the three solvents and with CHA and An in MeOH and AN is greatly depended on the stability of the zwitterionic intermediate. The effect of ring activation is due to the ground state stabilization and the more efficient delocalization of the negative charge with a nitro group than with a ring-nitrogen in the transition state. The low activation enthalpies ΔH# and the highly negative activation entropies ΔS# are due to the intramolecular hydrogen bonding with the ammonio hydrogen present in the transition state.

关键词： Nucleophilic Aromatic Substitution Reactions Kinetic Measurements 1-Hydroxybenzotriazole Solvent Effect Morpholine Cyclohexylamine and Aniline Uncatalyzed and Specific Base Catalyzed Mechanisms

A fatal case of Degos' disease which presented with recurrent intestinal perforation

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World Journal of Gastrointestinal Surgery 2011年第10期3卷 156-158页

作者： Mona Ahmadi Sevil Agabalaey Rafi Zhale faham Ramin Azhough Samad Beheshty Rooy Omid Rahmani Department of General Surgery and Pathology Imam Reza Hospital

Degos' disease,otherwise known as "malignant atrophic papulosis" is a rare vasculopathy with an unknown etiology characterized by typical cutaneous lesions.Involvement of the gastrointestinal(GI) tract is observed in approximately half of patients and small infarctions in the mucosa can cause perforation and resulting peritonitis,the leading cause of death.We present a fatal case of Degos' disease with skin and GI involvement,manifesting as recurrent intestinal perforations and peritonitis,in a 15-year-old Iranian boy.

关键词： Degos’disease Malignant atrophic papulosis Small bowel perforation