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development of a drill energy utilization index for aiding selection of drill machines in surface mines

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International Journal of Mining Science and Technology 2017年第3期27卷 393-399页

作者： Kumar Suraj Rahul Talreja murthy v.M.S.R. department of Mining Engineering Indian School of Mines Dhanbad India

drill machines used in surface mines, particularly in coal, is characterized by a very poor utilization （around 40%） and low availability （around 60%）. The main purpose of this study is to develop a drill selec- tion methodology and simultaneously a performance evaluation technique based on drill cuttings produced and drilling rate achieved. In all 28 blast drilled through were investigated. The drilling was accomplished by 5 different drill machines of Ingersoll-Rand and Revathi working in coal mines of Sonepur bazari （SECL） and block-II （bCCL）. The drills are Rotary and Rotary Percussive type using tri- cone rock roller bits. drill cuttings were collected and sieve analysis was done in the laboratory. Using Rosin Ramler diagram, coarseness index （CI）, mean chip size （d）, specific-st trace area （SSA） and charac- teristic particle size distribution curves for all the holes drilled were plotted. The predictor equation for drill penetration rate established through multiple regressions was found to have a very good correlation with an index of determination of 0.85. A comparative analysis of particle size distribution curves was used to evaluate the drill efficiency. The suggested approach utilises the area under the curve, after the point of trend reversal and brittleness ratio of the respective bench to arrive at drill energy utilization index （dEUI）, for mapping of drill machine to bench, The developed dEU1 can aid in selecting or mapping a right machine to right bench for achieving higher penetration rate and utilizations.

关键词： drill cutting parameter Coarseness index Mean chip size Specific surface area Particle size distribution curves drill energy ptilization index

A simple method for automatic recreation of railway horizontal alignments

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Railway Engineering Science 2025年第1期33卷 62-78页

作者： Alberte Castro Gerardo Casal duarte Santamarina Miguel E.vázquez‑Méndez Transportation and Infrastructure Engineering Universidade de Santiago de CompostelaEPSERúa Benigno Ledo27002 LugoSpain department of Applied Mathematics Universidade de Santiago de CompostelaEPSERúa Benigno Ledo27002 LugoSpain CITMAga Rúa de Constantino Candeira15782 Santiago de CompostelaSpain

This paper deals with the problem of recreating horizontal alignments of existing railway *** main objective is to propose a simple method for automatically obtaining optimized recreated alignments located as close as possible to an existing *** on a previously defined geometric model,two different constrained optimization problems are *** first problem uses only the information provided by a set of points representing the track centerline while the second one also considers additional data about the existing *** proposed methodology consists of a two-stage process in which both problems are solved consecutively using numerical *** main results obtained applying this methodology are presented to show its performance and to prove its practical usefulness:an academic example used to compare with other methods,and a case study of a railway section located in Parga(Spain)in which the geometry of its horizontal alignment is successfully recovered.

关键词： Railway horizontal alignment Geometrical model Constrained optimization problem Numerical resolution

A novel protocol for reviving of oil and natural gas wells

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Petroleum Research 2019年第3期4卷 276-281页

作者： R.v.v.Ramana murthy Naresh Kumar Katari N.Satya Sree Sreekantha b.Jonnalagadda division of Chemistry Vignan's Foundation for ScienceTechnology and Research UniversityVadlamudiGuntur 522213 Andhra PradeshIndia department of Chemistry GITAM deemed to be UniversityHyderabad502329TelanganaIndia School of Chemistry&Physics Westville CampusUniversity of KwaZulu-NatalP Bag X 54001Durban 4000South Africa

For effective cleaning of oil and gas wells and their revival,a novel fluid composition of enzyme-G with acid mixture together with corrosion inhibitor and selected additives is *** and field experiments endorse the effectiveness of the new fluid *** testing and analyzing the results with various treatment combinations,the procedure is *** efficacy is validated by treating various oil and natural gas *** communication provides a comprehensive description of the method for cleaning the oil and gas wells and their stimulation for improving the *** novel enzymes-G composition developed,effectively removes the impurities from the face of the wellbore,improve pore formation and create additional artificial channels to enhance the production of oil and *** developed protocols could also be used in injection wells to improve the injection rates.

关键词： Well stimulation Polymers breaking Acidization Fragmentation Corrosion inhibitor Enzyme G

Assessment of pot-hole subsidence risk for Indian coal mines

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International Journal of Mining Science and Technology 2015年第2期25卷 185-192页

作者： Lokhande d.Ritesh murthy vemavarapu M.S.R. vellanky venkateswarlu Singh b.Kalendra National Institute of Technology Raipur Indian School of Mines National Institute of Rock Mechanics Central Institute of Mining and Fuel Research

Ground subsidence induced by extraction of coal seam belowground brings about changes in surface environment leading to trough and pot-hole ***-hole subsidence is extremely hazardous and does not give any prior indication before its *** India,several pot-holes have occurred in the coal mines of South Eastern Coalfields Limited triggering the need for in-depth *** line with the requirement,literature review and field investigations were conducted to develop an in-depth understanding of various parameters influencing the occurrence of *** critical parameters identified were rock to soil ratio,depth to height of extraction ratio,brittleness index of rock and rock *** assessment of pot-hole subsidence has been done by developing an empirical rating approach named as pot-hole subsidence rating(PHSR),involving the critical parameters with suitable corrections for certain structural and mining conditions to obtain corrected PHSR(CPHSR).CPHSR was then applied for all the 34pot-holes studied and it was found that all the pot-holes fall under Class I and Class II category of risk representing a very high to high risk *** effort was made for the estimation of pot-hole depth utilizing the developed CPHSR in both the development and depillaring *** developed approach was found to yield consistent results in pot-hole depth prediction.

关键词： Underground coal mining Pot-hole subsidence PHSR CPHSR

Mechanical and thermal properties of AA7075/TiO2/Fly ash hybrid composites obtained by hot forging

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Progress in Natural Science:Materials International 2017年第4期27卷 474-481页

作者： K.v.Shivananda murthy d.P.Girish R.Keshavamurthy Temel varol Praveennath G.Koppad department of Mechanical Engineering Government Engineering Colleg 2. Department of Mechanical Engineering Dayananda Sagar College of Engineering 3. Department of Metallurgical and Materials Engineering Karadeniz Technical University 4. Department of Mechanical Engineering CMR Institute of Technology

In the present paper, multiple reinforcements TiO2 and fly ash were utilized for the fabrication of AA7075 matrix based hybrid composites using stir casting technique followed by hot forging. In hybrid composites, the fly ash content was fixed to 3 wt% while that of TiO2 was varied from 2.5 to 10 wt%. Scanning electron microscopy images revealed homogenous dispersion of both the reinforcements in AA7075 *** test was conducted to study the mechanical behaviour of hybrid composites. The hybrid composites showed increase in compressive strength with the incorporation of multiple reinforcements and further increased with the increase in the weight fractions of TiO2 particles. The coefficient of thermal expansion was measured between 50 and 250 ℃ with a high precision thermal mechanical analyser. The thermal coefficient of hybrid composites decreased with the addition of TiO2 and fly ash. However a slight decrease in thermal conductivity of hybrid composites was observed when compared to that of AA7075 alloy.

关键词： Hybrid composites Hot forging Mechanical properties Thermal properties

Performance evaluation of up-flow anaerobic sludge blanket(UASb) reactor for treatment of paper mill wastewater

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Journal of Environmental Sciences 2004年第2期16卷 194-198页

作者： M. Mahadevaswamy b.M. Sadashiva murthy A.R. Girijamma department of Environmental Engineering S.J.College of EngineeringDepartment of Environmental EngineeringS.J.College of EngineeringDepartment of Environmental EngineeringS.J.College of Engineering Mysore-570 006Karnataka StateIndiaMysore-570 006Karnataka StateIndiaMysore-570 006Karnataka StateIndia

The present study deals with the performance evaluation of the UASb reactor under varied organic loading rate(OLR) for the treatment of paper mill wastewater. The sludge granulation process started after 120 days from the start-up period. Sludge granules size was found to be 0 8 mm at OLR of 1 72 kgCOd/(m 3·d), which reached maximum size of about 1 0 to 1 2 mm at OLR of 2 1 kgCOd/(m 3·d). At the end of initial OLR of 1 0 kgCOd/(m 3·d) the vSS concentration was 12 86 gvSS/L, which got increased to 38 05 gvSS/L at the end of an OLR 2 1 kgCOd/(m 3·d). Most of the times vFA recorded were well within the limit of vFA reported in anaerobic fermentation process. Many times the pH observed was between 6 5 and 7 8, which is more favorable for any anaerobic process. It is also found that pH within the reactor increases along with the height of reactor. The total maximum biogas production was found to be 0 40 L/gCOd removals at OLR of 2 1 kgCOd/(m 3·d) and the maximum bOd removal at this stage was observed to be 90%.

关键词： UASb biogas anaerobic digestion sludge loading rate organic loading rate

Prolonged intermittent theta burst stimulation restores the balance between A_(2A)R-and A_(1)R-mediated adenosine signaling in the 6-hydroxidopamine model of Parkinson's disease

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Neural Regeneration Research 2025年第7期20卷 2053-2067页

作者： Milica Zeljkovic Jovanovic Jelena Stanojevic Ivana Stevanovic Milica Ninkovic Tihomir v.Ilic Nadezda Nedeljkovic Milorad dragic Laboratory for Neurobiology Department of General Physiology and BiophysicsFaculty of BiologyUniversity of BelgradeBelgradeSerbia Medical Faculty of Military Medical Academy University of DefenceBelgradeSerbia

An imbalance in adenosine-mediated signaling,particularly the increased A_(2A)R-mediated signaling,plays a role in the pathogenesis of Parkinson's *** therapeutic approaches fail to alter disease progression,demonstrating the need for novel approaches in *** transcranial magnetic stimulation is a non-invasive approach that has been shown to improve motor and non-motor symptoms of Parkinson's ***,the underlying mechanisms of the beneficial effects of repetitive transcranial magnetic stimulation remain *** purpose of this study is to investigate the extent to which the beneficial effects of prolonged intermittent theta burst stimulation in the 6-hydroxydopamine model of experimental parkinsonism are based on modulation of adenosine-mediated *** with unilateral 6-hydroxydopamine lesions underwent intermittent theta burst stimulation for 3 weeks and were tested for motor skills using the Rotarod ***,quantitative reverse transcription polymerase chain reaction,immunohistochemistry,and biochemical analysis of components of adenosine-mediated signaling were performed on the synaptosomal fraction of the lesioned caudate *** intermittent theta burst stimulation improved motor symptoms in 6-hydroxydopamine-lesioned animals.A 6-hydroxydopamine lesion resulted in progressive loss of dopaminergic neurons in the caudate *** with intermittent theta burst stimulation began 7 days after the lesion,coinciding with the onset of motor *** treatment with prolonged intermittent theta burst stimulation,complete motor recovery was *** improvement was accompanied by downregulation of the e N/Cd73-A_(2A)R pathway and a return to physiological levels of A_(1)R-adenosine deaminase 1 after 3 weeks of intermittent theta burst *** results demonstrated that 6-hydroxydopamine-induced degeneration reduced the expression of A_(1)R and elevated the expression of A_(2A)***

关键词： A_(1)R A_(2A)R adenosine receptors adenosine ecto-5′-nucleotidase intermittent theta burst stimulation non-invasive brain stimulation Parkinson's disease purinergic signalling

Magnetic and XPS studies of lithium lanthanide tetraphosphates LiLnP_4O_(12)(Ln=Nd,Gd,Er)

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Journal of Rare Earths 2013年第5期31卷 485-489页

作者： d.Petrov b.Angelov v.Lovchinov department of Physical Chemistry Plovdiv University"Paisii Hilendarski" 24 Tsar Asen Str. 4000 Plovdiv Bulgaria department of Inorganic and Physical Chemistry University of Food Technologies-Plovdiv26 Maritsa Blvd. 4002 Plovdiv Bulgaria Institute of Solid State Physics Bulgarian Academy of Sciences72Tsarigradsko Chaussee Blvd.1784 SofiaBulgaria

Magnetic susceptibilities of flux-grown single crystals of LitnP4012 （Ln=Nd, Gd, Er） were measured in the temperature range of 2-300 K. The compounds were paramagnetic, and obeyed the Curie-Weiss law in the entire temperature interval, without magnetic phase transitions, and with effective magnetic moments close to those of the corresponding free Ln3＋ ions. X-ray photoelec- tron spectroscopy was applied to determine the positions of core-level electrons relative to the Fermi level： Li is; Ln 4f, 5p, 5s, 4d, 3d; P 2s, 2p; O 1s, 2s. The binding energies in these compounds were found slightly shifted compared to the respective values of the same elements.

关键词： lithium lanthanide tetraphosphates single crystals magnetic properties XPS spectroscopy rare earths

Effect of exhaust gas recirculation and ethyl hexyl nitrate additive on biodiesel fuelled diesel engine for the reduction of NOx emissions

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Frontiers in Energy 2012年第3期6卷 304-310页

作者： K. vENKATESWARLU b. S. R. murthy v. v. SUbbARAO K. vijaya KUMAR Mechanical Engineering department K.L University Guntur 522502India Mechanical Engineering department Q.I.S College of Engineering and Technology Ongole 523272 India Mechanical Engineering department J.N.T.U Kakinada Kakinada533033 India

Cetane improvers reduce the ignition delay, which in turn reduces the combustion temperatures thereby reduce NOx emissions. Exhaust gas recirculation （EGR） proved to be an effective way to reduce the NOx emissions. In this present experimental work, a combination of exhaust gas recirculation and cetane improver ethyl hexyl nitrate （EHN） is used to investigate the performance and exhaust emissions of a single cylinder four stroke naturally aspirated direct injection and air cooled diesel engine. Test results show that the brake thermal efficiency increases with the increase in the percentage of EGR which is accompanied by a reduction in brake specific fuel consumption and exhaust gas temperatures, and that bio- diesel with cetane improver under 20% EGR reduces NOx emissions by 33% when compared to baseline fuel without EGR. However carbon monoxide （CO）, hydro carbon （HC） and smoke emissions increase with an increase in percentage of EGR.

关键词： additive exhaust gas recirculation (EGR),emissions ethyl hexyl nitrate (EHN) performance