检索结果-南通市图书馆

A laboratory study of stress arching around an inclusion due to pore pressure changes

在线全文

学校读者我要写书评

暂无评论

Journal of Rock Mechanics and Geotechnical Engineering 2018年第4期10卷 678-693页

作者： hani Asaei Mahdi Moosavi Mohammad Ali Aghighi University of Tehran TehranIran

When the pore pressure in a porous rock changes, stress arching will occur within the rock and the surrounding region. Stress arching ratio is defined as the total stress changes in the porous rock to the pore pressure change in the region. The region may have the same or different elastic moduli with the surrounding rock, which is usually referred to as inclusion or inhomogeneity. Stress arching is responsible for many geomechanical problems encountered during production or injection; in addition, it is a crucial parameter in stress estimation during field development. This paper aims to present laboratory measurements of vertical stress arching ratio in a material surrounding the inclusion(inhomogeneity).To the authors’ knowledge, few laboratory experiments have been reported on direct measurement of stress arching. The inclusion is a cylindrical sandstone(44 mm in diameter and 50 mm in height)embedded in a larger cylindrical sandstone(150 mm in diameter and 154 mm in height), both of which are made synthetically. These two parts are separated and sealed by a internal polyurethane *** stress changes are recorded by a mini hydraulic sensor embedded in surrounding rock. Laboratory results are compared to those obtained by numerical models. These models are checked with analytical formulations. The results of numerical models show a good agreement with laboratory *** numerical results also indicate that the sensor response is affected by elastic properties of the internal sleeve. According to the sensitivity analysis performed, in the absence of the internal sleeve,properties of the inclusion have significant effects on the surrounding stress arching induced.

关键词： Stress arching Laboratory test Large-scale sample Synthetic sandstone

Volumetric analysis of rock mass instability around haulage drifts in underground mines

在线全文

学校读者我要写书评

暂无评论

Journal of Rock Mechanics and Geotechnical Engineering 2018年第1期10卷 60-71页

作者： Shahé Shnorhokian Bryce MacNeil hani S.Mitri Department of Mining and Materials Engineering McGill University

Haulage networks are vital to underground mining operations as they constitute the arteries through which blasted ore is transported to surface. In the sublevel stoping method and its variations, haulage drifts are excavated in advance near the ore block that will be mined out. Numerical modeling is a technique that is frequently employed to assess the redistribution of mining-induced stresses, and to compare the impact of different stope sequence scenarios on haulage network stability. In this study,typical geological settings in the Canadian Shield were replicated in a numerical model with a steeplydipping tabular orebody striking EW. All other formations trended in the same direction except for two dykes on either side of the orebody with a WNW-ESE strike. Rock mass properties and in situ stress measurements from a case study mine were used to calibrate the model. Drifts and crosscuts were excavated in the footwall and two stope sequence scenarios-a diminishing pillar and a center-out one-were implemented in 24 mining stages. A combined volumetric-numerical analysis was conducted for two active levels by comparing the extent of unstable rock mass at each stage using shear,compressive, and tensile instability criteria. Comparisons were made between the orebody and the host rock, between the footwall and hanging wall, and between the two stope sequence scenarios. It was determined that in general, the center-out option provided a larger volume of instability with the shear criterion when compared to the diminishing pillar one(625,477 m~3 compared to 586,774 m~3 in the orebody; 588 m~3 compared to 403 m~3 in the host rock). However, the reverse was true for tensile(134,298 m~3 compared to 128,834 m~3 in the orebody; 91,347 m~3 compared to 67,655 m~3 in the host rock)instability where the diminishing pillar option had the more voluminous share.

关键词： Haulage drifts Rock mass instability Volumetric analysis Stope sequences Numerical modeling

Machine learning methods for rockburst prediction-state-of-the-art review

在线全文

学校读者我要写书评

暂无评论

International Journal of Mining Science and Technology 2019年第4期29卷 565-570页

作者： Yuanyuan Pu Derek B.Apel Victor Liu hani Mitri School of Mining and Petroleum Engineering University of AlbertaEdmonton T6G 2R3Canada Department of Mining and Materials Engineering McGill UniversityMontreal H3A 2T6Canada

One of the most serious mining disasters in underground mines is rockburst *** can lead to injuries and even fatalities as well as damage to underground openings and mining *** has forced many researchers to investigate alternative methods to predict the potential for rockburst ***,due to the highly complex relation between geological,mechanical and geometric parameters of the mining environment,the traditional mechanics-based prediction methods do not always yield precise *** the emergence of machine learning methods,a breakthrough in the prediction of rockburst occurrence has become possible in recent *** paper presents a state-ofthe-art review of various applications of machine learning methods for the prediction of rockburst ***,existing rockburst prediction methods are introduced,and the limitations of such methods are highlighted.A brief overview of typical machine learning methods and their main features as predictive tools is then *** current applications of machine learning models in rockburst prediction are surveyed,with related mechanisms,technical details and performance analysis.

关键词： Rockburst prediction Burst liability Artificial neural network Support vector machine Deep learning

Functional trait profiles and diversity of trees regenerating in disturbed tropical forests and agroforests in Indonesia

在线全文

学校读者我要写书评

暂无评论

Forest Ecosystems 2022年第3期9卷 323-334页

作者： Subekti Rahayu Sidiq Pambudi Dikdik Permadi Hesti L.Tata Endri Martini Saida Rasnovi hani S.Nuroniah Roeland Kindt Mohamad Nugraha Sonya Dewi Meine van Noordwijk World Agroforestry(ICRAF) BogorIndonesia FOERDIA Ministry of Environment and ForestryBogorIndonesia Botany Department Syiah Kuala UniversityBanda AcehIndonesia Plant Production Systems Wageningen UniversityWageningenthe Netherlands

A main question in restoration of degraded forests and forest landscapes recovering from logging and fire is what to expect from natural regeneration through surviving propagules in the soil or seed sources and associated dispersal agents from the surrounding landscape mosaic,as alternative to tree *** diversity in secondary forests may be high,but based on newcomer species of low wood density and long-distance,abiotic dispersal *** compiled and analyzed three pairs of case studies(totaling 815 plots and 11.8 ha)of secondary forests recovering from logging,fire and conversion to agroforest in Sumatra and Kalimantan(Indonesia)on mineral *** on tree species diversity,wood density frequency distribution(indicative of successional status)and dispersal modes were compared with those of less disturbed comparator forests in the same *** undisturbed lowland dipterocarp forest in Kalimantan had close to 200 species of trees(>10 cm diameter)at a 1-ha sample scale(and 450 at a 10-ha scale).After repeated fires a sample area of 2 ha was needed to reach the same species ***-based logging had little impact on tree species *** rubber agroforest with low-intensity management beyond rubber planting,50 tree species were found at a 1-ha scale and close to 100 species in 3 *** Kalimantan forest after repeated fires had a markedly higher fraction of lowwood-density trees(40%),but otherwise,all forests sampled were similar in overall wood density *** logged forest managed by a local community(village forest)and rubber agroforest in Sumatra contained larger fractions of heavy-wood-density *** majority of trees(50%–70%)had birds,bats and primates as dispersal agents in all *** logged forests had higher fractions of autochorous species(15%)compared to other ***(wind-dispersed)species,especially Macaranga lowii,were most common(20%)in lowland dipterocarp *** be

关键词： Agroforestry Dipterocarp Dispersal modes Kalimantan Landscape restoration Natural regeneration Sumatra Wood density

Data-Fusion for Epidemiological Analysis of Covid-19 Variants in UAE

在线全文

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2021年第9期68卷 3895-3913页

作者： Anoud Bani-hani Anaïs Lavorel Newel Bessadet Zayed University DubaiUnited Arab Emirates Staffordshire University Stoke-on-TrentST42DEUnited Kingdom Keele University NewcastleST55BGUnited Kingdom

Since December 2019,a new pandemic has appeared causing a considerable negative global *** SARS-CoV-2 first emerged from China and transformed to a global pandemic within a short *** virus was further observed to be spreading rapidly and mutating at a fast pace,with over 5,775 distinct variations of the virus observed globally(at the time of submitting this paper).Extensive research has been ongoing worldwide in order to get a better understanding of its behaviour,influence and more importantly,ways for reducing its *** analytics has been playing a pivotal role in this research to obtain valuable insights into understanding and fighting against the spread of ***,this is time and resource intensive,making it difficult to observe and quickly identify the impact of *** such as the spread or virulence could explain the three months delay in revealing the new virus variant in the *** paper presents an extensive correlation analysis of the effect caused by the different SARS-CoV-2 strains,and their influence on the population across diverse factors,such as propagation and fatality rates,during the peak of the pandemic,with a focus on two major countries in the Middle East,the United Arab Emirate(UAE)and the Kingdom of Saudi Arabia(KSA).This research aims to investigate the epidemiological behaviour of the Coronavirus’genomic variants over time in the UAE,compared with the KSA,where correlation analysis is carried out for a number of cases,deaths and their statistical *** results of the analysis highlight very interesting insights into the epidemiological impact of the Covid-19 genomic behaviour in both countries,which could lead to important actions taken to minimize the impact on wider public health,possibly saving lives,and the *** instance,our method identifies a potential correlation between a spike in the number of deaths per case of 5.5 observed in the UAE by March 24th,with the emergence of new

关键词： SARS-CoV-2 genome covid-19 public health pandemic epidemiology case study United Arab Emirates UAE Kingdom of Saudi Arabia KSA

Using Portable Gamma-Ray Spectrometry for Testing Uranium Migration: A Case Study from the Wadi El Kareim Alkaline Volcanics,Central Eastern Desert, Egypt

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Geologica Sinica(English Edition) 2018年第6期92卷 2214-2232页

作者： Osama K. DESSOUKY hani H. ALI Nuclear Materials Authority P.O.Box 530El MaadiCairoEgypt

The 300±20 Ma anomalously radioactive trachytes of Wadi El Kareim, central Eastern Desert, are a significant example of U-mineralization related to the alkaline volcanics in Egypt. Extensive portable gamma-ray spectrometric data has been utilized to identify geological factors controlling uranium mobility in the geological units along the three detailed study locations of Kab Al-Abyad, South Wadi(W) Al-Tarafawy and W. Al-Farkhah; their eT h/eU ratios averaging around 4.1, 3.7 and 5.6 respectively. Quantitative analysis with the integration of mobility maps and geological studies suggest two systems controlling U-migration within the geological units(confined system and unconfined system). In the confined system, the syngenetically formed U have experienced mobility after leaching and are redistributed in the presence of an incorporation carrier during transportation(probably as carbonate complexes). Then the retardant for uranium is achieved by sorption or by coprecipitation with the aid of Fe oxy-hydroxide, and finally the formation of immobile secondary U-bearing minerals takes place along a lithogeochemical trap. In contrast to the confined system, the unconfined one is basically lacking the lithogeochemical trap which influences the final accumulation of U-bearing minerals. The radioactivity of the trachyte rocks arises from the radioactive minerals uranophane and betauranophane with U-and/or Th-bearing minerals samarskite, Th-rich REE silicates, monazite and allanite.

关键词： radioactivity uranium migration systems alkaline volcanics Egypt

Analysis of particulate behavior in porous media

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2008年第4期29卷 511-516页

作者： hani I.Siyyam M.H.Hamdan Department of Mathematics and Physics College of Arts and SciencesQatar UniversityP.O.Box 2713DohaQatar Department of Mathematical Sciences University of New BrunswickP.O.Box 5050Saint JohnNew BrunswickCanada

In this work, we analyze the behavior of the particle phase in the flow of a particle-laden mixture through a porous medium. An attempt is made to model the diffusion and dispersion processes, and to quantify the devi... 详细信息

关键词： porous media dusty gases particle behavior

Electric Vehicles Lithium-Polymer Ion Battery Dynamic Behaviour Charging Identification and Modelling Scheme

在线全文

学校读者我要写书评

暂无评论

Journal of Dynamics, Monitoring and Diagnostics 2023年第3期2卷 170-176页

作者： Peter Makeen hani AGhali Saim Memon Fang Duan Electrical Engineering Department Faculty of EngineeringThe British University in Egypt(BUE)El-Sherouk11837 Egypt London Centre for Energy Engineering Division of Electrical and Electronic EngineeringSchool of EngineeringLondon South Bank UniversityLondonSE10AA UK School of Engineering Arden UniversityCoventryCV34FJ UK Jiangsu Sanyou Dior Energy-Saving New Materials Co. Ltd(SANYOU DIOR)ChangzhouJiangsu 213149China Department for Engineering School of Engineering and the Built EnvironmentBirmingham City UniversityBirmingham B47XG UK

Lithium-ion batteries are considered the substantial electrical storage element for electric vehicles(EVs). The battery model is the basis of battery monitoring, efficient charging, and safety management. Non-linearmodelling is the key to representing the battery and its dynamic internal parameters and performance. This paperproposes a smart scheme to model the lithium-polymer ion battery while monitoring its present charging currentand terminal voltage at various ambient conditions (temperature and relative humidity). Firstly, the suggestedframework investigated the impact of temperature and relative humidity on the charging process using the constantcurrent-constant voltage (CC-CV) charging protocol. This will be followed by monitoring the battery at thesurrounding operating temperature and relative humidity. Hence, efficient non-linear modelling of the EV batterydynamic behaviour using the Hammerstein-Wiener (H-W) model is implemented. The H-W model is considered ablack box model that can represent the battery without any mathematical equivalent circuit model which reducesthe computation complexity. Finally, the model beholds the boundaries of the charging process, not affecting onthe lifetime of the battery. Several dynamic models are applied and tested experimentally to ensure theeffectiveness of the proposed scheme under various ambient conditions where the temperature is fixed at40°C and the relative humidity (RH) at 35%, 52%, and 70%. The best fit using the H-W model reached 91.83% todescribe the dynamic behaviour of the battery with a maximum percentage of error 0.1 V which is in goodagreement with the literature survey. Besides, the model has been scaled up to represent a real EV and expressedthe significance of the proposed H-W model.

关键词： battery identification electric vehicles EV fast charging Hammerstein-Wiener Lithium-polymer ion battery

Probiotics and gut health:A special focus on liver diseases

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2010年第4期16卷 403-410页

作者： Silvia Wilson Gratz Hannu Mykkanen hani S El-Nezami Rowett Institute of Nutrition and Health University of Aberdeen Greenburn Road Aberdeen AB21 9SNUnited Kingdom School of Public Health and Clinical Nutrition University of KuopioPO Box 162770211 KuopioFinland Food and Health Research Centre University of KuopioPO Box 162770211 KuopioFinland School of Biological Sciences University of Hong KongS5-13 Kadoorie Biological Sciences BuildingPokfulamHong KongChina

Probiotic bacteria have well-established beneficial ef-fects in the management of diarrhoeal *** evidence suggests that probiotics have the potential to reduce the risk of developing inflammatory bowel diseases and intestinal bacterial overgrowth after gut *** liver health,the main benefits of probiotics might occur through preventing the production and/or uptake of lipopolysaccharides in the gut,and therefore reducing levels of low-grade *** immune stimulation by probiotics through processes involving dendritic cells might also be beneficial to the host immunological status and help prevent pathogen *** fat metabolism also seems to be influenced by the presence of commensal bacteria,and potentially by probiotics;although the mechanisms by which probiotic might act on the liver are still ***,this might be of major importance in the fu-ture because low-grade inflammation,hepatic fat infil-tration,and hepatitis might become more prevalent as a result of high fat intake and the increased prevalence of obesity.

关键词： Probiotics Liver Gut Endotoxin Barrier function Ethanol Bacterial overgrowth Translocation