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Articles 33601 - 33630 of 302513

Full-Text Articles in Physical Sciences and Mathematics

Smallholder Dairy Farmers In The Peruvian Andes Fulfilling The Role Of Extension Agents, C. S. Pinares-Patino, J. Manhire, R. Garcia Ticllacuri, J. L. Bernal Madrid, V. M. Velez Marroquin Feb 2022

Smallholder Dairy Farmers In The Peruvian Andes Fulfilling The Role Of Extension Agents, C. S. Pinares-Patino, J. Manhire, R. Garcia Ticllacuri, J. L. Bernal Madrid, V. M. Velez Marroquin

IGC Proceedings (1993-2023)

Dairy farming in the Peruvian Andes is mostly undertaken by smallholder farmers (4-6 cows/family) and of relatively recent development. In fact, over the last 2 decades dairy farming at high altitudes (3,500‒4200 masl) has grown rapidly, replacing the camelids and sheep farming that once predominated. Dairying growth has been catalysed by subsides from state and private organizations. It promotes high input systems based on feedlot technology. Compared to sheep and camelids farming, dairying at the Andes does not have yet an inherent local/indigenous knowledge associated to it. High altitude Andean ecosystems pose many constraints for dairy farming (hypoxia and high …


Pastoralists’ Perception Of Poverty: A Case Of The Somali And Turkana Of Northern Kenya, W. P. Watete, Kogi-Makau Feb 2022

Pastoralists’ Perception Of Poverty: A Case Of The Somali And Turkana Of Northern Kenya, W. P. Watete, Kogi-Makau

IGC Proceedings (1993-2023)

Poverty is a complex phenomenon, without a single definition or standard methods of reducing it. Income based methods of assessing poverty have been shown to have limitations that undermine their application in measuring and attacking poverty among pastoral households. Stages of progress method of poverty assessment was used to assess poverty among pastoral households in Turkana and Mandera Counties of Northern Kenya. Three hundred and three hundred and fifty-four households in Mandera and Turkana Counties respectively were sampled across three different livelihood zones: pastoral, agro-pastoral and off-farm. Accumulation of livestock was regarded as a key indicator of wealth among pastoral …


Pastoralist Conservation: Local Ecological Knowledge And Collective Action For Grassland Conservation In Sierra De Segura (Spain), P. Sanosa-Cols, F. Ravera, F. Dominguez, M. Ventura Feb 2022

Pastoralist Conservation: Local Ecological Knowledge And Collective Action For Grassland Conservation In Sierra De Segura (Spain), P. Sanosa-Cols, F. Ravera, F. Dominguez, M. Ventura

IGC Proceedings (1993-2023)

Even if Pastoralism is not practised anymore by a majority of families in the Sierra de Segura (south-eastern Andalusia, Spain), it is still considered a paradigmatic way of life and management of its highlands and a key cultural heritage deeply rooted in local identity. In this article we explore two pastoral communities of this region, Santiago and Pontones, with their body of situated knowledge of the territory and natural resources, which helps pastoralists to organize their livelihoods, while requiring collective organization to manage access to grasslands. Through an ethnographic research based on participant observation and in-depth interviews, we explore the …


Intensification Of Pastoralism As A Driver Of Degradation In The Algerian Steppe, S. Bencherif, P. Manzano Feb 2022

Intensification Of Pastoralism As A Driver Of Degradation In The Algerian Steppe, S. Bencherif, P. Manzano

IGC Proceedings (1993-2023)

Land degradation linked to pastoralism use has been a worldwide concern for decades. A biological approach has often been use to understand such phenomena, usually disregarding economic and social factors. Radical transformations of pastoralism at the Algerian steppe constitute a good case study to provide an integrated understanding and to better orient development in other pastoralist areas across the world. Different actions by the public sector since the 1960s, as well as the land legislation adopted and the strong agricultural subventions during 2000-2010, have favored a massive conversion of land and resource management. This translates into conversion of many pastures …


Perceptions Of Rangeland Degradation In The Peruvian Altiplano Dry Puna And Implications, C. Turin, J. Gilles Feb 2022

Perceptions Of Rangeland Degradation In The Peruvian Altiplano Dry Puna And Implications, C. Turin, J. Gilles

IGC Proceedings (1993-2023)

The Peruvian altiplano’s dry puna is the main feed source for specialized alpaca pastoralist systems. Experts argue that rangelands are severely degraded and have formulated policies and programs to address this. However, these programs have had little success. This paper presents a qualitative case study of the perceptions of rangeland degradation held in three Aymara communities, by range scientists of academia, personnel of NGOs operating in the region and by government officers. We found that each of these groups had distinct views of the level and causes of degradation in the region. Differences in perceptions undermined cooperation and trust between …


Endangered Sustainable Innovation: Indigenous Milk Hygiene And Preservation Techniques By Maasai Too Valuable To Lose, J. Y. Laffa, C. R. Mcculloch, D. Schoder Feb 2022

Endangered Sustainable Innovation: Indigenous Milk Hygiene And Preservation Techniques By Maasai Too Valuable To Lose, J. Y. Laffa, C. R. Mcculloch, D. Schoder

IGC Proceedings (1993-2023)

The indigenous Parakuyo Maasai communities of Tanzania are traditional pastoralists who depend on fresh cow’s milk as a staple food. However, the arid climate and a lack of clean water challenge milk production and conventional milk hygiene practices.

By conducting informational interviews in eight Parakuyo Maasai regions and 13 districts of Tanzania we sought to identify the key indigenous plants preferred and establish their traditional manner of use. A semi-structured questionnaire was designed to: (i) determine the plants used, (ii) the parts used, (iii) methods of preparation and utensil smoking, (iv) therapeutic applications and associated health benefits of these plants, …


Developing A Glossary Of People-Focused Terms Related To Rangelands And Grasslands, Dana Kelly, Katherine I. Johnsen, Chris Magero, Tungalag Ulambayer, Ann Waters-Bayer Feb 2022

Developing A Glossary Of People-Focused Terms Related To Rangelands And Grasslands, Dana Kelly, Katherine I. Johnsen, Chris Magero, Tungalag Ulambayer, Ann Waters-Bayer

IGC Proceedings (1993-2023)

Excellent glossaries on rangelands and grasslands have been developed by the Society for Range Management (SRM), the International Grassland Congress (IGC) and the International Rangeland Congress (IRC). However, these are largely confined to biophysical and technical terminology and contain very few concepts referring to social, institutional and policy aspects of using rangelands and grasslands. After the 10th IRC in Saskatoon, Canada, in 2016, an informal group started to develop a glossary of such “people-focused” terms. The short and non-academic definitions are meant to improve communication and understanding by users/practitioners in rangeland and grassland management, policymakers, teachers, students, journalists and …


Could Cheese Be The Missing, Hard, Stable Currency To Fortify Self-Sufficiency Of Pastoralist Communities?, D. Schoder, J. Y. Laffa Feb 2022

Could Cheese Be The Missing, Hard, Stable Currency To Fortify Self-Sufficiency Of Pastoralist Communities?, D. Schoder, J. Y. Laffa

IGC Proceedings (1993-2023)

Traditional pastoral existence in Africa has always necessitated close, sustainable interaction with a harsh natural environment. Pastoralists, such as the indigenous Parakuyo Maasai of Tanzania traditionally depend on fresh cow’s milk as a staple. They are among the few African ethnic groups that still live as small, socially intact associations close to nature. Unfortunately, fresh milk is difficult to store and inevitably, times of plenty fluctuate with the times of hunger that threaten cultural retreat. Milk storage is particularly challenging in an arid climate without refrigeration and at such times, survival takes precedence over prosperity. We describe an ongoing pilot …


Comparative Analysis Of Cbrm Cases In Kenya, Ethiopia And Tunisia, I. N. Nganga, L. W. Robinson, B. Eba, F. Flintan, E. M. Ontiri, M. Sghaier, N. H. Abdu, S. S. Moiko Feb 2022

Comparative Analysis Of Cbrm Cases In Kenya, Ethiopia And Tunisia, I. N. Nganga, L. W. Robinson, B. Eba, F. Flintan, E. M. Ontiri, M. Sghaier, N. H. Abdu, S. S. Moiko

IGC Proceedings (1993-2023)

In various countries, development and conservation organizations and national policymakers have been experimenting with ways of applying the community-based natural resource management approach to the unique social and biophysical characteristics of pastoralist rangeland settings, with mixed results. We carried out comparative case study research on community-based rangeland management (CBRM) in a variety of settings in Ethiopia, Kenya and Tunisia with the objective of identifying what kinds of strategies and methods work in which social and ecological contexts. We used an “options by context” approach guided by a research protocol that includes key variables and descriptors for characterizing the implementing organization’s …


Comparative Analysis Of Agri-Food Systems For Extensive Livestock In The High Pyrenees And Creation Of A Multicriterian Tool For Its Evaluation, Laia Motos, Federica Ravera Feb 2022

Comparative Analysis Of Agri-Food Systems For Extensive Livestock In The High Pyrenees And Creation Of A Multicriterian Tool For Its Evaluation, Laia Motos, Federica Ravera

IGC Proceedings (1993-2023)

The main objective of this study is to compare the different agri-food systems of extensive livestock (ecological and conventional) of big and small ruminants (cattle and sheep respectively) in high Pyrenees. This objective is formulated by looking at the general lack of knowledge of the population regarding the functionality of these systems, the changes of management that have been introduced in the recent years, especially in terms of commercialization, and the different capacity of response of extensive livestock systems to climate change and other socio-economic complementary changes. Attributes and indicators have been selected for the comparative evaluation of livestock systems, …


Analysis Of Rangeland Perceptions Among Potential Land Redistribution Beneficiaries In South Africa: How Well Do Potential Emerging Farmers Know Their Rangelands?, S. Zantsi Feb 2022

Analysis Of Rangeland Perceptions Among Potential Land Redistribution Beneficiaries In South Africa: How Well Do Potential Emerging Farmers Know Their Rangelands?, S. Zantsi

IGC Proceedings (1993-2023)

Sound rangeland management is one of the key factors for a successful and viable commercial livestock production in grass fed production systems. However, such knowledge is perceived to be lacking in small-scale livestock farmers, who farm on degraded and overgrazed communal rangelands despite being regarded as prime beneficiaries of the land redistribution programme in the stalling South African land reform. Largely, it is also not known in details how much the potential future commercial farmers know about their rangelands. This study analyses perception of the prime land redistribution beneficiaries—potential emerging farmers, who were surveyed randomly in three South African provinces. …


Revisiting Prejudiced Polygons: Adapting A Familiar Activity During A Time Of Unknowns, Anne M. Ho, Jaime J. Mccauley, Tara T. Craig Feb 2022

Revisiting Prejudiced Polygons: Adapting A Familiar Activity During A Time Of Unknowns, Anne M. Ho, Jaime J. Mccauley, Tara T. Craig

Journal of Math Circles

This article describes the design process behind various iterations of Prejudiced Polygons, a Math Circles activity about segregation. In particular, we frame our discussion around two guiding principles from User Experience (UX) Design in thinking about the interconnected components of a Math Circles session, which includes all the people, the physical or virtual setting, the technology, and the world context. Additionally, we describe how we think about developing a “low floor" and “high ceiling" for math content, social issues content, as well as technology and access.


Development Of Effectual Substrates For Sers By Nanostructurs-Coated Porous Silicon, Fatima J. Moaen, Hammad R. Humud, Fouad G. Hamzah Feb 2022

Development Of Effectual Substrates For Sers By Nanostructurs-Coated Porous Silicon, Fatima J. Moaen, Hammad R. Humud, Fouad G. Hamzah

Karbala International Journal of Modern Science

The current paper provides an efficient method for making active and effectual substrates used for detecting molecules by improving surface-enhanced Raman scattering (SERS). These substrates were fabricated using nanostructure-coated porous silicon. The nanostructures were prepared through the electrical exploding wire (EEW) technique. The silver nanowires (AgNWs) were coated with a polydopamine (PDA) layer to form an AgNWs@PDA colloidal solution. Then, the Ag wire was electrically exploded in the colloidal solution to form the (AgNWs@PDA@AgNPs) plasmonic nanostructures as a metal-insulator-metal. The effect of the plasmonic nanostructures’ morphologies on the absorptances spectra and SERS activities were studied utilising Rhodamine 6G (Rh6G) dye …


Preparation And Characteristics Study Of Porous Silicon For Vacuum Sensor Application, Noor S. Dawood, Mehdi Q. Zayer, Muslim F. Jawad Feb 2022

Preparation And Characteristics Study Of Porous Silicon For Vacuum Sensor Application, Noor S. Dawood, Mehdi Q. Zayer, Muslim F. Jawad

Karbala International Journal of Modern Science

Vacuum is a technique that can be employed to measure pressures less than atmosphere (101325 mbar), the vacuum is too important in numerous fields of life. In the present research, the sensor of vacuum has been produced using a porous layer of silicon (Psi). N-type of silicon wafer (Si) has been used for formulating Psi samples utilizing photo-electrochemical etching (PECE) technique. The experimental work was carried out under different etching times (30, 60, and 90 min) while fixing the other parameters, including (24%) Hydrofluoric (HF) acid and (20 mA/cm2) current density. The pore width and depth and porosity …


Sensitivity Of The West Antarctic Ice Sheet To +2 °C (Swais 2c), Molly O. Patterson, Richard H. Levy, Denise K. Kulhanek, Tina Van De Flierdt, Huw Horgan, Gavin B. Dunbar, Timothy R. Naish, Jeanine Ash, Alex Pyne, Darcy Mandeno, J. Paul Winberry Feb 2022

Sensitivity Of The West Antarctic Ice Sheet To +2 °C (Swais 2c), Molly O. Patterson, Richard H. Levy, Denise K. Kulhanek, Tina Van De Flierdt, Huw Horgan, Gavin B. Dunbar, Timothy R. Naish, Jeanine Ash, Alex Pyne, Darcy Mandeno, J. Paul Winberry

Geological Sciences Faculty Scholarship

The West Antarctic Ice Sheet (WAIS) presently holds enough ice to raise global sea level by 4.3 m if completely melted. The unknown response of the WAIS to future warming remains a significant challenge for numerical models in quantifying predictions of future sea level rise. Sea level rise is one of the clearest planet-wide signals of human-induced climate change. The Sensitivity of the West Antarctic Ice Sheet to a Warming of 2 C (SWAIS 2C) Project aims to understand past and current drivers and thresholds of WAIS dynamics to improve projections of the rate and size of ice sheet …


Design Demand Trend Acquisition Method Based On Short Text Mining Of User Comments In Shopping Websites, Zhiyong Xiong, Zhaoxiong Yan, Huanan Yao, Shangsong Liang Feb 2022

Design Demand Trend Acquisition Method Based On Short Text Mining Of User Comments In Shopping Websites, Zhiyong Xiong, Zhaoxiong Yan, Huanan Yao, Shangsong Liang

Machine Learning Faculty Publications

In order to facilitate designers to explore the market demand trend of laptops and to establish a better “network users-market feedback mechanism”, we propose a design and research method of a short text mining tool based on the K-means clustering algorithm and Kano mode. An improved short text clustering algorithm is used to extract the design elements of laptops. Based on the traditional questionnaire, we extract the user’s attention factors, score the emotional tendency, and analyze the user’s needs based on the Kano model. Then, we select 10 laptops, process them by the improved algorithm, cluster the evaluation words and …


Synthesis And Evaluation Of 11c-Labeled Triazolones As Probes For Imaging Fatty Acid Synthase Expression By Positron Emission Tomography, James M. Kelly, Thomas M. Jeitner, Nicole N. Waterhouse, Wenchao Qu, Ethan J. Linstad, Banafshe Samani, Clarence Williams Jr., Anastasia Nikolopoulou, Alejandro Amor-Coarasa, Stephen G. Dimagno, John W. Babich Feb 2022

Synthesis And Evaluation Of 11c-Labeled Triazolones As Probes For Imaging Fatty Acid Synthase Expression By Positron Emission Tomography, James M. Kelly, Thomas M. Jeitner, Nicole N. Waterhouse, Wenchao Qu, Ethan J. Linstad, Banafshe Samani, Clarence Williams Jr., Anastasia Nikolopoulou, Alejandro Amor-Coarasa, Stephen G. Dimagno, John W. Babich

Chemistry Department: Faculty Publications

Cancer cells require lipids to fulfill energetic, proliferative, and signaling requirements. Even though these cells can take up exogenous fatty acids, the majority exhibit a dependency on de novo fatty acid synthesis. Fatty acid synthase (FASN) is the rate-limiting enzyme in this process. Expression and activity of FASN is elevated in multiple cancers, where it correlates with disease progression and poor prognosis. These observations have sparked interest in developing methods of detecting FASN expression in vivo. One promising approach is the imaging of radiolabeled molecular probes targeting FASN by positron emission tomography (PET). However, although [11C]acetate uptake by …


Online Masters In Data Science, Joanna Burkhardt Feb 2022

Online Masters In Data Science, Joanna Burkhardt

Library Impact Statements

No abstract provided.


Initial Soil Conditions Outweigh Management In A Cool-Season Dairy Farm's Carbon Sequestration Potential, Kyle A. Arndt, Eleanor E. Campbell, Chris D. Dorich, A. Stuart Grandy, Timothy S. Griffin, Peter Ingraham, Apryl L. Perry, Ruth K. Varner, Alexandra R. Contosta Feb 2022

Initial Soil Conditions Outweigh Management In A Cool-Season Dairy Farm's Carbon Sequestration Potential, Kyle A. Arndt, Eleanor E. Campbell, Chris D. Dorich, A. Stuart Grandy, Timothy S. Griffin, Peter Ingraham, Apryl L. Perry, Ruth K. Varner, Alexandra R. Contosta

Faculty Publications

Pastures and rangelands are a dominant portion of global agricultural land and have the potential to sequester carbon (C) in soils, mitigating climate change. Management intensive grazing (MIG), or high density grazing with rotations through paddocks with long rest periods, has been highlighted as a method of enhancing soil C in pastures by increasing forage production. However, few studies have examined the soil C storage potential of pastures under MIG in the northeastern United States, where the dairy industry comprises a large portion of agricultural use and the regional agricultural economy. Here we present a 12-year study conducted in this …


Simian Immunodeficiency Virus Infection Mediated Changes In Jejunum And Peripheral Sars-Cov-2 Receptor Ace2 And Associated Proteins Or Genes In Rhesus Macaques, Nongthombam Boby, Xuewei Cao, Kelsey Williams, Shiva Kumar Goud Gadila, Monica N. Shroyer, Peter J. Didier, Sudesh K. Srivastav, Arpita Das, Kate Baker, Qiuying Sha, Bapi Pahar Feb 2022

Simian Immunodeficiency Virus Infection Mediated Changes In Jejunum And Peripheral Sars-Cov-2 Receptor Ace2 And Associated Proteins Or Genes In Rhesus Macaques, Nongthombam Boby, Xuewei Cao, Kelsey Williams, Shiva Kumar Goud Gadila, Monica N. Shroyer, Peter J. Didier, Sudesh K. Srivastav, Arpita Das, Kate Baker, Qiuying Sha, Bapi Pahar

Michigan Tech Publications

Angiotensin converting enzyme-2 (ACE2) and associated proteins play a pivotal role in various physiological and pathological events, such as immune activation, inflammation, gut barrier maintenance, intestinal stem cell proliferation, and apoptosis. Although many of these clinical events are quite significant in SIV/HIV infection, expression profiling of these proteins has not been well reported. Considering the different pathological consequences in the gut after HIV infection, we hypothesized that the expression of ACE2 and associated proteins of the Renin-angiotensin system (RAS) could be compromised after SIV/HIV infection. We quantified the gene expression of ACE2 as well as AGTR1/2, ADAM17, and TMPRSS2, and …


Table Of Contents, The Editors Feb 2022

Table Of Contents, The Editors

Coal Geology & Exploration

No abstract provided.


Water Inrush Warning System Of Deep Limestone In Panxie Mining Area Based On Multi-Source Data Mining, Bi Bo, Chen Yongchun, Xie Hao, An Shikai, Xu Yanfei Feb 2022

Water Inrush Warning System Of Deep Limestone In Panxie Mining Area Based On Multi-Source Data Mining, Bi Bo, Chen Yongchun, Xie Hao, An Shikai, Xu Yanfei

Coal Geology & Exploration

Under the long-term water-rock interaction, the hydrochemical composition of deep limestone water in each aquifer is different. Such factors as crustal movement and mining influence have led to the hydraulic connection between aquifers. Major water inrush accidents often occur when the deep high-pressure limestone water bursts into the mine with the shallow limestone water as a channel. On the basis of water level data of 182 surface hydrological observation holes in nine coal mines in Panxie Mining Area of Huainan Coalfield from 2015 to 2018, and the temporal and spatial law of water level change of each hydrological observation hole …


Comprehensive Correlation Technology Of Coal And Rock Layers In Mines For Intelligent Mining, Wang Haijun, Liu Shande, Ma Liang, Zhu Yuying, Shu Jiansheng, Wang Xiangye Feb 2022

Comprehensive Correlation Technology Of Coal And Rock Layers In Mines For Intelligent Mining, Wang Haijun, Liu Shande, Ma Liang, Zhu Yuying, Shu Jiansheng, Wang Xiangye

Coal Geology & Exploration

The coal-rock correlation runs through the whole process of the coal geological exploration and the mine production stage. In view of the difficult problems of the coal-rock correlation in the mine production stage, such as short distance, multi-coal seams and complex structure, taking Huoshaopu Coal Mine in Panxian Coalfield of Guizhou Province as the research object, through the analysis of the geological exploration data, combined with the surface gas investigation boreholes, the underground geological survey, the gas parameter test, the marker layer suitable for the mine production stage was extracted from the coal-rock correlation marker layers established during the geological …


Mechanical Properties And Acoustic Emission Characteristics Of Sandstone Under Natural And Saturated Conditions, Zhang Yin, Li Zhe, Song Shikang, Zhao Yi, Li Hao Feb 2022

Mechanical Properties And Acoustic Emission Characteristics Of Sandstone Under Natural And Saturated Conditions, Zhang Yin, Li Zhe, Song Shikang, Zhao Yi, Li Hao

Coal Geology & Exploration

In order to study the mechanical properties and acoustic emission (AE) characteristics of sandstone with different grain sizes in the process of damage and failure under saturated and natural conditions, we carried out uniaxial compression tests and AE tests on three kinds of sandstone under saturated and natural conditions to study the mechanical properties and AE characteristics under the uniaxial stress state. The test results show that the average compressive strength of coarse-grained sandstone, medium-grained sandstone, and fine-grained sandstone are 54.23 MPa, 53.56 MPa, 59.46 MPa respectively under natural conditions, and 35.62 MPa, 31.79 MPa and 29.10 MPa under saturated …


Development And Test Analysis Of Borehole In-Situ Rock Mass Shear Measurement System, Zhang Youzhen, Liu Yanjie, Zhong Zicheng Feb 2022

Development And Test Analysis Of Borehole In-Situ Rock Mass Shear Measurement System, Zhang Youzhen, Liu Yanjie, Zhong Zicheng

Coal Geology & Exploration

The pre-drilled rock shear measurement system can measure the internal friction angle and cohesion of in-situ rock in mines. Compared with the traditional laboratory test and field tests, such method can keep the essential state of rock mass to the maximum extent, and obtain the test data conveniently and quickly. Firstly, the overall design idea of the system was elaborated, and the pre-drilled in-situ rock shear equipment was successfully developed and the data acquisition and storage software platform was built. Secondly, the test data processing method was developed, based on the working principle of the shearing instrument, and the specific …


Application Of Advanced Regional Treatment Technology Of Hard Roof In Buertai Coal Mine Of Shendong Coal Group, Yang Junzhe, Wang Zhenrong, Lyu Qingxu, Yang Sen, Li Guo, Zheng Kaige Feb 2022

Application Of Advanced Regional Treatment Technology Of Hard Roof In Buertai Coal Mine Of Shendong Coal Group, Yang Junzhe, Wang Zhenrong, Lyu Qingxu, Yang Sen, Li Guo, Zheng Kaige

Coal Geology & Exploration

The hard roof is a difficult problem in rock stratum control. The breaking and instability of high hard rock strata often induces strong coal pressure disasters, seriously threatening the safety production in coal mines. Hard roof control is one of the major problems in coal mine safety production. In response to the problems of large thickness, high hardness of the coal seam roof and its difficulty in collapse in Buertai Coal Mine in Shendong Mining Area, the hydraulic fracturing mechanism and technical advantages of directional long borehole segmented hydraulic fracturing are analyzed. The location of boreholes is determined based on …


Down-Hole Ø550 Mm Super Large Diameter Coal Seam Borehole Drilling Technology And Equipment And Its Engineering Application, Sun Yongxin Feb 2022

Down-Hole Ø550 Mm Super Large Diameter Coal Seam Borehole Drilling Technology And Equipment And Its Engineering Application, Sun Yongxin

Coal Geology & Exploration

For the prpose of improving the gas control efficiency and reduce the cost in the goaf of “U” ventilation face, the ø550 mm super-large diameter borehole was used to replace the cross-heading buried pipe for gas drainage in goaf. According to the characteristics of super-large diameter borehole and the technical problems existed in construction, a ZDY15000LP super-large diameter spiral drilling rig with maximum torque 15000 N·m, maximum penetration 700 kN, and maximum stroke 1.3 m has been developed, which adopted the two-body layout of main engine and pump station, and the innovative design of key parts such as main engine, …


Acoustic Emission Characteristics And Fracture Response Behavior Of Hard Rock-Like Material Under Influence Of Loading Rate, Zhang Zekun, Song Zhanping, Cheng Yun, Huo Runke, Song Wanxue, Wang Kuisheng, Wang Tong, Yang Tengtian, Liu Wei Feb 2022

Acoustic Emission Characteristics And Fracture Response Behavior Of Hard Rock-Like Material Under Influence Of Loading Rate, Zhang Zekun, Song Zhanping, Cheng Yun, Huo Runke, Song Wanxue, Wang Kuisheng, Wang Tong, Yang Tengtian, Liu Wei

Coal Geology & Exploration

For the purpose of clarifying the correlation between Acoustic Emission(AE) and rupture response characteristics and loading rate in the failure and instability of hard rocks, uniaxial compression tests and acoustic emission tests were conducted on hard rock-like material samples at different loading rates to analyze the characteristics of mechanical parameters, AE phenomena and rupture response characteristics of hard rock-like material, and to obtain the early warning information of the rock failure based on the information on AE parameters. The results show that the peak strength, elastic modulus and peak strain of hard rock-like material have the loading rate effect. The …


Prediction Of Burnt Rock Areas And Water Abundance Based On The Electrical-Magnetic Method, Yan Shunshang, Wang Ling, Dong Fangying, Liu Xiao, Lyu Xiaolei Feb 2022

Prediction Of Burnt Rock Areas And Water Abundance Based On The Electrical-Magnetic Method, Yan Shunshang, Wang Ling, Dong Fangying, Liu Xiao, Lyu Xiaolei

Coal Geology & Exploration

For the purpose of accurately ascertaining the distribution range and water abundance degree of the burnt rock mass in the mining area, a new set of methods for prediction and exploration of burnt area boundaries and water-richness is presented based on overall consideration of the electrical-magnetic characteristics of the geological body. Three geophysical prospecting methods including high-precision magnetic survey, transient electromagnetic method and high-density electrical method are used for joint exploration are applied to the exploration of the burnt area of Shajihai No.1 Minefield in Xinjiang. The results show that the southern boundary of the burned area moves slightly compared …


Effects Of Different Tempering Temperatures On The Microstructure And Mechanical Properties Of A Low-Carbon High-Strength Steel, Lu Tian, Wen Guodong, Ma Xiaolin, Li Jun, Ju Pei, Wang Shiqing Feb 2022

Effects Of Different Tempering Temperatures On The Microstructure And Mechanical Properties Of A Low-Carbon High-Strength Steel, Lu Tian, Wen Guodong, Ma Xiaolin, Li Jun, Ju Pei, Wang Shiqing

Coal Geology & Exploration

The mechanical properties of low carbon high strength steel materials used in drilling equipment can be improved effectively by adjusting tempering temperatures of different heat treatments to obtain different material composition. The heat treatment and tempering temperatures were set at 610℃, 630℃ and 650 ℃ respectively, and the microstructure of this low-carbon high-strength steel was compared and analyzed by metallographic microscope and Scanning Electron Microscope(SEM). After tempering, the microhardness, tensile properties and impact energy of the structure were measured respectively by the microhardness tester, universal material testing machine and impact testing machine. The research results show that the performance of …