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Review of current coal rib control practices

Underground Space 2023年第2期9卷 53-75页

作者： Dogukan guner Samuel Nowak Taghi Sherizadeh Maurice Sunkpal khaled mohamed Yuting Xue Department of Mining and Explosives Engineering Missouri University of Science and TechnologyRollaMO 65409USA CDC NIOSH Pittsburgh Mining Research DivisionPittsburghPA 15236USA

The instability of coal ribs in underground mines continues to result in the injuries and fatalities of mine *** proper esti-mation and evaluation of primary and secondary support for coal ribs is still a challenging problem in the field of ground control science and requires further research and *** mining operations have various support design criteria and support methodologies for strata control,most rib support designs are still based on experience and local *** review study is intended to summarize the currently applied practices for rib support and control in various countries and mining ***,critical parameters that con-trol the amount and type of required rib support are considered and *** study revealed that among these parameters that control the stability of coal ribs,mining depth,rib height,cleat orientation/condition,and coal strength are the most significant ***,current rib support application methods were also *** to rock mass classification systems,some studies proposed a rib control rating system for practical estimation of the current rib condition and to estimate primary support *** studies are classified and summarized into two groups(categorical and empirical)based on the required inputs and *** based coal rib rating systems were closely examined,and the usefulness and intuitive aspects of each rating system were *** comprehensive literature review demonstrates that the Australian rating system,Analysis and Design of Rib Support(ADRS),and the new *** system,Coal Pillar Rib Rating(CPRR),are highly applicable for their regions.

关键词： Coal rib ground control Rib support Rib control techniques ADRS CPRR

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Spectral transformation-based technique for reducing effect of limited pre-correlation bandwidth in the gNSS receiver filter in presence of noise and multipath

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Journal of Systems Engineering and Electronics 2020年第2期31卷 252-265页

作者： TITOUNI Salem ROUABAH khaled ATIA Salim FLISSI Mustapha MEZAACHE Salaheddine BOUHLEL mohamed Salim Electronics and Advanced Telecommunications Laboratory of Electronics Department University of Mohamed El Bachir El IbrahimiBordj Bou Arreridj 34031Algeria Sciences of Electronics Technologies of Information and Telecommunications Research UnitHigher Institute of Biotechnology of SfaxSfax 3038Tunisia

This paper proposes an efficient scheme to reduce the pre-correlation bandwidth effect in the global navigation satellite system(gNSS)receiver filtering *** is mainly based on the application of a spectral transformation to the satellite-emitted signal that effectively reduces its *** the receiver's end,this operation causes the spreading of noise over a much wider band than that used by the radio frequency ***,the resulting auto-correlation function in the acquisition process acquires properties that enhance considerably the performance of the receiver in the presence of the multipath and noise disturbing *** simulation results demonstrate that the proposed method is a plausible solution for both multipath and noise problems in the gNSS applications for any limited value of the pre-correlation bandwidth in the receiver filter.

关键词： precorrelation bandwidth spectral transformation multipath noise

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The role of exclusive enteral nutrition in the management of orofacial granulomatosis in children

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World Journal of Pediatrics 2016年第4期12卷 421-424页

作者： mohamed Mutalib khaled Bezanti Mamoun Elawad Fevronia Kiparissi Department of Pediatric gastroenterology Great Ormond Street Hospital NHS Foundation Trust

Background:Orofacial granulomatosis(OFg)is a term used to describe a persistent,painless swelling of lips and orofacial *** can be associated with ulceration,gingival hypertrophy and cobble stone appearance of the buccal *** is commonly associated with Crohn’s disease and can precede the intestinal manifestation of the *** enteral nutrition(EEN)is a recognized treatment for induction of remission for Crohn’s *** aim of this study was to review the use of EEN in the management of OFg in ***:Retrospective review of medical records of all children diagnosed with OFg between 2007 and 2012 was *** of comorbidities,progression to inflammatory bowel disease(IBD)and response to EEN was ***:Twenty-nine children were included,mean age at diagnosis was 9 years(standard deviation 3.9)*** children had isolated OFg and 19 had OFg and IBD,of which 12 presented with OFg and IBD and 7 developed IBD *** time to progression to IBD was 33 months(inter quartile range:9.8-85.5).Twenty-two children completed 6 weeks of EEN,and 19 showed clinical improvement in the OFg ***:EEN appears to be an effective treatment option for children with isolated OFg or OFg and IBD.

关键词： gastroenterology inflammatory bowel disease inflammation orofacial granulomatosis

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Measurements of natural radionuclides in soil samples from Upper Egypt

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Nuclear Science and Techniques 2008年第5期19卷 302-307页

作者： Shaban Ramadan mohamed HARB khaled SALAHEL DIN Abd Elbaset ABBADY mohamed Abd Elleh ALI Rolf MICHEL Physics Department Faculty of ScienceSouth Valley University Center for Radiation Protection and Radioecology Hanover University (ZSR)

This paper presents the results of natural radioactivity measured for the soil of Qena using gamma-ray spectrometry at ZSR,Hanover University,*** samples of radioactive concentrations of ^(238)U-series (^(234)Th, ^(214)pb,and^(214)Bi),^(232)Th-series (^(228)Ac,^(212)pb,and ^(208)T1) and ^(40)K were *** objectives were set:(1) activity levels by surface soil sampling at 0～30 cm depth,(2) dose rates of gamma radiation,radium equivalent,index hazard, and effective dose,and (3) ambient dose rates.

关键词：土壤环境放射能 γ光谱测定法辐射暴露环境剂量

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Effectiveness and safety of subthreshold vibration over suprathreshold vibration in treatment of muscle fatigue in elderly people

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World Journal of Clinical Cases 2023年第15期11卷 3434-3443页

作者： Ayman A mohamed Esra khaled Asma Hesham Ahmed Khalf Physical Therapy Nahda UniversityBeni Suef 23435Egypt Physical Therapy Beni-Suef UniversityBeni Suef 32456Egypt

Muscle fatigue is common in many populations,particularly *** increases the incidence of muscle fatigue and delays its *** is a huge debate about the current treatments for muscle fatigue,particularly in ***,it has been discovered that mechanoreceptors have an important role as a sensory system in sensing muscle fatigue which could enhance the body's response to muscle *** function of mechanoreceptors could be enhanced by applying either suprathreshold or subthreshold *** suprathreshold vibration improves muscle fatigue,it can cause desensitization of cutaneous receptors,discomfort,and paresthesia,which are barriers to clinical *** vibration has been approved as a safe and effective method of training for mechanoreceptors;however,its use and effectiveness in muscle fatigue have never been tested or *** physiological effects of subthreshold vibration in the treatment of muscle fatigue include:(1)Enhancing the function of mechanoreceptors themselves;(2)Increasing the firing rate and function of alpha motor neurons;(3)Increasing blood flow to fatigued muscles;(4)Decreasing the rate of muscle cell death in elderlies(sarcopenia);and(5)Driving motor commands and allow better performance of muscles to decrease fatigue *** conclusion,the use of subthreshold vibration could be a safe and effective treatment for muscle fatigue in *** could enhance recovery from muscle ***,Subthreshold Vibration is safe and effective in treating muscle fatigue in comparison to suprathreshold vibration.

关键词： Subthreshold Vibration Muscle Fatigue Elderly people

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Methods to shorten the duration of an external fixator in the management of tibial infections

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World Journal of Orthopedics 2011年第9期2卷 85-92页

作者： khaled M Emara khaled Abd Al ghafar mohamed Ahmed Al Kersh Orthopaedic Surgery Ain Shams University HospitalsCairo 0020Egypt Lecturer in Orthopaedic Surgery Ain Shams UniversityCairo 0020Egypt Assistant Lecturer of Orthopaedic Surgery Ain Shams UniversityCairo 0020Egypt

Massive segmental bone loss due to chronic osteomyelitis represents a considerable challenge to orthopedic surgeons and is a limb threatening *** only option available in such a clinical situation is segment transport using the Ilizarov technique of distraction osteogenesis;yet the most common problem in cases of bone transport with the Ilizarov technique in massive bone loss,is the long duration of the *** addition to autologous bone grafting,several mechanical,biologic,and external physical treatment modalities may be employed to promote bone formation and maturation during segment transport in osteomyelitis *** approaches include compressive loading of the distraction regenerate,increased frequency of small increments of distraction,and *** nailing and hemicorticotomy can reduce the time in external fixation;however,these techniques are associated with technical difficulties and *** application of low-intensity pulsed ultrasound or pulsed electromagnetic fields may shorten the duration of external *** promising modalities include diphosphonates,physician-directed use(off-label use)of bone morphogenetic proteins,and local injection of bone marrow aspirate and platelet gel at the osteotomy ***-designed clinical studies are needed to establish safe and effective guidelines for various modalities to enhance new bone formation during distraction osteogenesis after segment transfer.

关键词： Ilizarov Bone infection Intramedullary nail Hemicorticotomy Tibiofibular synostosis Fibular transport

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Coal rib response during bench mining: A case study

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International Journal of Mining Science and Technology 2018年第1期28卷 107-113页

作者： Morgan M.Sears John Rusnak Mark Van Dyke gamal Rashed khaled mohamed Michael Sloan ground Control Branch NIOSH Pittsburgh Mining Research Division

In 2016, room-and-pillar mining provided nearly 40% of underground coal production in the United *** the past decade, rib falls have resulted in 12 fatalities, representing 28% of the ground fall fatalities in *** coal *** of these 12 fatalities(75%) have occurred in room-andpillar *** objective of this research is to study the geomechanics of bench room-and-pillar mining and the associated response of high pillar ribs at overburden depths greater than 300 *** paper provides a definition of the bench technique, the pillar response due to loading, observational data for a case history, a calibrated numerical model of the observed rib response, and application of this calibrated model to a second site.

关键词： Deep cover Bench mining Thick seam Retreat mining Rib response Rib support

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Facies Analysis and Biostratigraphy of the Miocene Sequence,Cairo-Suez District,Egypt

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Journal of Earth Science 2017年第1期28卷 1-8页

作者： Abdelbaset El-Sorogy mohamed Abd-Elmoneim Ahmed Mowafi khaled Al-Kahtany Hisham gahlan Department of geology and geophysics College of Science King Saud University Riyadh 11451 Saudi Arabia geology Department Faculty of Science Zagazig University Zagazig 44519 Egypt

Miocene siliciclastic-carbonate deposits are widely exposed in Cairo-Suez District, Egypt. These deposits are underlain and overlain by continental sediments of Oligocene and post Miocene, respectively. Three stratigraphic sections were investigated at gabals geneife, Homeira and gharra. Lithostrtigraphically, the Miocene sequence could be differentiated into two main rock units representing shallow deposits with relatively intermittent deep marine incursions. These are from base to top, gharra Formation and genefe Formation. Detailed macrofossils investigations led to the recognition of four macrofossil zones, namely Alectryonella plicatula-Crassostrea frondosa Range Zone, Echinolampas amplus-Scutella ammonis Range Zone, Chlamys（Macrochlamys） sardoa-Chlamys（Argopecten） submalvinae Range Zone, and Chlamys gentoni-Pecten（Oppenheimopecten） benedictus-Pecten（P.） ziziniae Assemblage Zone. Microfacies analysis and identified taxa indicated that the Miocene sequence was deposited in transgressive-regressive cycles ranged from near shore, warm shallow inner to middle shelf marine environments with storm influence during the accumulation of the oyster banks.

关键词： facies analysis biostratigraphy Miocene Cairo-Suez District Egypt.

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Simulating advance distance in border irrigation systems based on the improved method of characteristics

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International Journal of Agricultural and Biological Engineering 2021年第3期14卷 156-162页

作者： Kaihua Liu Xiyun Jiao Weihua guo mohamed khaled Salahou Zhe gu College of Hydrology and Water Resources Hohai UniversityNanjing 210098China State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering Nanjing 210098China College of Agricultural Science and Engineering Hohai UniversityNanjing 210098China Cooperative Innovation Center for Water Safety and Hydro Science Hohai UniversityNanjing 210098China

Improving the simulation accuracy of the advance distance based on the method of characteristics is essential to develop numerical solutions for simulating surface *** of volume balance in the traditional method of characteristics(T-MC),the position of critical flow is determined to simulate the advance distance in the improved method of characteristics(I-MC),which is used in border irrigation systems with rapid variation in inflow discharge in the current ***,the zones of both subcritical and supercritical flow were firstly distinguished to determine the position of the critical flow point,which was also the upstream boundary of the wetting front region,and then the advance distance was calculated by applying the diffusive wave equation in the wetting front *** results showed that the I-MC accurately simulated the advance distance with high determination coefficients(0.984-0.998)and low errors(root mean square error of 0.35-1.56 min and coefficient of residual mass of 0.01-0.06),which performed much better than the *** I-MC provided a suitable and simple numerical simulation tool to improve the establishment of numerical surface irrigation models.

关键词： border irrigation numerical solution advance distance method of characteristics

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genetic and morphological divergence in the purple sea urchin Paracentrotus lividus(Echinodermata,Echinoidea)across the African Mediterranean coast

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Acta Oceanologica Sinica 2017年第12期36卷 52-66页

作者： Temim Deli mohamed Hbib Ben Attia Rym Zitari-Chatti khaled Said Noureddine Chatti Laboratory of genetics Biodiversity and Enhancement of Bioresources(LR11ES41)University of MonastirHigher Institute of Biotechnology of MonastirMonastir 5000Tunisia

The present investigation focuses on population structure analysis of the purple sea urchin Paracentrotus lividus across the African Mediterranean coast, with the main aim of assessing the influence of the Siculo-Tunisian Strait on gene flow disruption in this highly dispersive echinoid species. For this purpose, patterns of morphological and genetic variation were assessed among its populations from the western and eastern Mediterranean coasts. A total of 302 specimens from seven Tunisian sites were collected and examined for morphometric variability at twelve morphometric traits. Concordant results, inferred from CDA（canonical discriminant analyses）, pairwise NPMANOVA（non parametric multivariate analysis of variance） comparisons and MDS（multidimensional scaling） plot, unveiled significant inter-population differences in the measured traits among the studied populations. Furthermore, the combined use of the one way ANOSIM（analysis of similarities） and the Discriminant/Hotelling analysis allowed unravelling two morphologically differentiated groups assigned to both western and eastern Mediterranean basins. The SIMPER（similarity percentages） routine analysis showed that total dry weight, test diameter and spine length were major contributors to the morphometric separation between locations and between groups. Pattern of phenotypic divergence discerned in P. lividus across the Siculo-Tunisian Strait is interestingly in congruence with that inferred from the genetic investigation of the purple sea urchin populations from the same region based on the analysis of the mt DNA COI（cytochrome oxidase I） gene in 314 specimens from nineteen locations covering a wider geographic transect, streching westward to the Algerian coast and eastward to the Libyan littoral. The specific haplotypic composition characterizing each Mediterranean basin,as inferred from the minimum spanning network, confirmed the geographic partioning of genetic variation, as revealed by F-statistics and AMO

关键词： Paracentrotus lividus Siculo-Tunisian Strait morphological differentiation COI genetic divergence

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