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A review on recent advancements in biodegradable Mg-Ca alloys

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Journal of Magnesium and Alloys 2022年第8期10卷 2094-2117页

作者： Manas Ranjan Sahu T.S.Sampath kumar uday Chakkingal Department of Metallurgical and Materials Engineering Indian Institute of Technology MadrasChennai 600036India

The binary Mg-Ca alloys are drawing increasing attention as temporary implant materials because of their excellent biocompatibility,biodegradability, and good mechanical properties. However, their applications are limited due to their high degradation rates in the human physiological environment, the consequent release of hydrogen gas, and rapid loss in mechanical properties. Furthermore, biocompatibility depends upon the degradability of the material. Various researchers have demonstrated that these issues can be addressed by control of Ca content, thermo-mechanical processing to obtain suitable microstructures, deposition of surface coatings, etc. In this manuscript, a detailed review of published literature on Mg-Ca alloys is presented. The challenges and future directions of research in this area are also described.

关键词： Mg-Ca alloy Degradation Temporary implant Biocompatibility

Measurement-while-drilling technique and its scope in design and prediction of rock blasting

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International Journal of Mining Science and Technology 2016年第4期26卷 711-719页

作者： Rai Piyush Schunnesson Hakan Lindqvist Per-Arne kumar uday Department of Mining Engineering Indian Institute of Technology Banaras Hindu University Varanasi 221005 India Division of Mining and Geotechnical Engineering Lulea Technological University Lulea 97187 Sweden Department of Mining Engineering Lulea Technological University Lulea 97187 Sweden Division of Operations and Maintenance Engineering Lulea Technological University Lulea 97187 Sweden

With rampant growth and improvements in drilling technology, drilling of blast holes should no longer be viewed as an arduous sub-process in any mining or excavation process. Instead, it must be viewed as an important opportunity to quickly and accurately measure the geo-mechanical features of the rock mass on-site, much in advance of the downstream operations. It is well established that even the slightest variation in lithology, ground conditions, blast designs vis-a-vis geologic features and explosives performance, results in drastic changes in fragmentation results. Keeping in mind the importance of state-of-the-art measurement-while-drilling （MWD） technique, the current paper focuses on integrating this technique with the blasting operation in order to enhance the blasting designs and results. The paper presents a preliminary understanding of various blasting models, blastability and other related concepts, to review the state-of-the-art advancements and researches done in this area. In light of this, the paper highlights the future needs and implications on drill monitoring systems for improved information to enhnnrp th~ hl^tin~ r^HIt~

关键词： Rock blasting Drill monitoring parameters Rock factor Drill rod vibrations

Copper Ameliorates Fluoride Toxicity in Fluoride and Molybdenum Fed Rabbits

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Biomedical and Environmental Sciences 2013年第4期26卷 311-313页

作者： Arjun L KHANDARE uday kumar Priyanka SHANKAR Shanker RAO Food and Drug Toxicology Centre National Institute of NutritionIndian Council of Medical ResearchPOJama-I-OsmaniaHyderabad-500007Andhra PradeshIndia Department of Pathology National Institute of NutritionHyderabadIndia

Hydrofluorosis is a major public health problem in India, which is aggravated by presence or absence of some minerals in water or food. Fluoride by itself or in combination with other elements like molybdenum （Mo） in diet or water changes excretion/retention of bone minerals. Sorghum and pearl millet grown and consumed in fluorosis endemic areas contained significantly higher amounts of Mo than that grown in non-fluorotic areas in India.

关键词： Copper Ameliorates Fluoride Toxicity in Fluoride and Molybdenum Fed Rabbits body

Recharge and vulnerability assessment of groundwater resources in North west India:Insights from isotope-geospatial modelling approach

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Geoscience Frontiers 2024年第1期15卷 247-262页

作者： Annadasankar Roy Sitangshu Chatterjee uday kumar Sinha Anil kumar Jain Hemant Mohokar Ajay Jaryal Tirumalesh Keesari Harish Jagat Pant Isotope and Radiation Application Division Bhabha Atomic Research CentreTrombayMumbai–400085India Homi Bhabha National Institute Mumbai 400094India Central Ground Water Board AhmedabadGujaratIndia

Recent studies indicate dwindling groundwater quantity and quality of the largest regional aquifer system in North West India,raising concern over freshwater availability to about 182 million population residing in this *** agricultural activities have resulted severe groundwater pollution in this area,demanding a systematic vulnerability assessment for proactive *** vulnerability assessment models encounter drawbacks due to subjectivity,complexity,data-prerequisites,and spatial-temporal *** study incorporates isotopic information into a weighted-overlay framework to overcome the above-mentioned limitations and proposes a novel vulnerability assessment *** isotope methodology provides crucial insights on groundwater recharge mechanisms(18O and 2H)and dynamics(3H)-often ignored in vulnerability *** characterisation of precipitation helped in establishing Local Meteoric Water Line(LMWL)as well as inferring contrasting recharge mechanisms operating in different *** aquifer(depth<60 m)showed significant evaporative signature with evaporation loss accounting up to 18.04%based on Rayleigh distillation ***-aquifer connections were apparent from Kernel Density Estimate(KDE)and isotope correlations.A weighted overlay isotope-geospatial model was developed combining 18O,3H,aquifer permeability,and water level *** central and northern parts of study area fall under least(0.29%)and extremely(1.79%)vulnerable zones respectively,while majority of the study area fall under moderate(42.71%)and highly vulnerable zones(55.20%).Model validation was performed using groundwater NO3-concentration,which showed an overall accuracy up to 82%.Monte Carlo Simulation(MCS)was performed for sensitivity analysis and permeability was found to be the most sensitive input parameter,followed by 3H,18O,and water *** the vulnerability map with Land Use Land Cover(LULC)and population density maps

关键词： Agricultural pollution Data scarcity Recharge mechanism Rayleigh distillation Isotope-geospatial model Vulnerability assessment

Deposition of atmospheric pollutant and their chemical characterization in snow pit profile at Dokriani Glacier,Central Himalaya

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Journal of Mountain Science 2018年第10期15卷 2236-2246页

作者： Shipika SUNDRIYAL Tanuj SHUKLA Lekhendra TRIPATHEE Dwarika Prashad DOBHAL Sameer kumar TIWARI uday BHAN Centre for Glaciology Wadia Institute of Himalayan GeologyDehradun-248001UtturakhandIndia National Institute of Hydrology Roorkee-247667UttarakhandIndia Indian Institute oj:Technology Kanpur-208016Uttar PradeshIndia State Key Laboratory of Cryospheric Science Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou730000China Wadia Institute of Himalayan Geology Dehradun-248001UttarakhandIndia University of Petroleum and Energy Studies BidholiDehradun-248001UttarakhandIndia

The uncertainty in assessing the numerous atmospheric pollutants transported via wind from arid and semi-arid regions is affecting the glacial ecosystem. In our study area due to the complexity of the system, a prominent seasonal difference noticed among major ions(Ca^(2+), Mg^(2+), SO_4^(2-), and NO_3^-). There is a need for understanding the ions cycling as a whole and the directionality of the feedback loops in the system. Therefore, we provide an appraisal of our current hypothesis for seasonal difference in major ion concentration from snow samples for two corresponding years(2013 and 2015) at Dokriani Glacier. A systematic study of chemical compositionsin the shallow snow pit from Dokriani Glacier was undertaken for the pre-monsoon season to understand the cycling of major ions from atmosphere to solute acquisition process. The intimating connections of ions cycling in snow and its temporal behavior was observed and analyzed through various statistical tests. Among major ions, the SO_4^(2-)has the highest concentration among anions on an average considered as 14.21% in 2013 and 29.46% in 2015. On the other side Ca^(2+) is the dominant cation contributing 28.22% in 2013 and 15.3% in 2015 on average. The average ratio of Na+/Cl-was higher in 2013 whereas lower in 2015. The backward trajectory analysis suggests the possible sources of the ions transported from Central Asia through the Western Disturbance(WD) as a prominent source of winter precipitation mainly in the Central Himalaya. Ionicconcentration of Ca^(2+) in cations was highly dominated while in anion SO_4^(2-)played the major role. Factor analysis and correlation matrix suggested that, the precipitation chemistry is mostly influenced by anthropogenic, crustal, and sea salt sources over the studied region. The elemental cycling through ocean, atmosphere and biosphere opens up new ways to understand the geochemical processes operating at the glacierized catchments of the Himalaya. Moreover, increasing the

关键词： Western disturbance Central Himalaya Factor analysis Correlation analysis Snow Stratigraphy Atmospheric pollutants

Lipid-nanoparticle-enabled nucleic acid therapeutics for liver disorders

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Acta Pharmaceutica Sinica B 2024年第7期14卷 2885-2900页

作者： Porkizhi Arjunan Durga Kathirvelu Gokulnath Mahalingam Ashish kumar Goel uday George Zacharaiah Alok Srivastava Srujan Marepally Center for Stem Cell Research(A Unit of inStem Bengaluru)Christian Medical College CampusBagayamVellore 632002Tamil NaduIndia Manipal academy for higher education Mangalore 576104KarnatakaIndia Department of Hematology Christian Medical College&HospitalVellore 632004Tamil NaduIndia Department of Hepatology Christian Medical College&HospitalVellore 632004Tamil NaduIndia

Inherited genetic disorders of the liver pose a significant public health *** transplantation is often limited by the availability of donor livers and the exorbitant costs of immunosuppressive *** overcome these limitations,nucleic acid therapy provides a hopeful alternative that enables gene repair,gene supplementation,and gene silencing with suitable *** viral vectors are the most efficient and preferred for gene therapy,pre-existing immunity debilitating immune responses limit their *** a potential alternative,lipid nanoparticle-mediated vectors are being explored to deliver multiple nucleic acid forms,including pDNA,mRNA,siRNA,and ***,we discuss the broader applications of lipid nanoparticles,from protein replacement therapy to restoring the disease mechanism through nucleic acid delivery and gene editing,as well as multiple preclinical and clinical studies as a potential alternative to liver transplantation.

关键词： Lipid nanoparticle Liver disorders Gene therapy Gene editing Nucleic acid delivery pDNA mRNA siRNA ASO Clinical trials

Effect of laser surface melting on surface integrity of Al-4.5Cu composites reinforced with SiC and MoS2

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Transactions of Nonferrous Metals Society of China 2020年第2期30卷 344-362页

作者： Praveen kumar BANNARAVURI Anil kumar BIRRU uday Shanker DIXIT Department of Mechanical Engineering Karunya Institute of Technology and ScienceCoimbatoreTamil Nadu 641114India Department of Mechanical Engineering National Institute of Technology ManipurImphal 795004India Department of Mechanical Engineering Indian Institute of Technology GuwahatiAssam 781039India

Two types of composites were prepared with Al-4.5Cu alloy as a matrix using stir casting *** was reinforced with 10wt.%of Si C and 2wt.%of *** other was reinforced with 10wt.%of Si C and 4wt.%of *** surfaces were remelted using a CO2 laser beam with an objective to study the influence of laser surface melting(LSM).The topography,microhardness,corrosion resistance and wear resistance of the laser melted surfaces were *** surface integrity after LSM was compared with as-cast *** enhanced the microhardness and wear resistance of the surface in each *** of the laser melted surface was low and corrosion resistance was ***,LSM can be conveniently applied to enhancing the surface integrity of the aluminium ***,there is an optimum laser specific energy,around 38 J/m^2 in this study,for obtaining the best surface integrity.

关键词： aluminium composites silicon carbide molybdenum disulfide laser surface melting microhardness corrosion resistance

Reliability and maintainability analysis of electrical system of drum shearers

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Journal of Coal Science & Engineering(China) 2011年第2期17卷 192-197页

作者： SEYED Hadi Hoseinie MOHAMMAD Ataei REZA Khalokakaie uday kumar Faculty of Mining Petroleum ＆ Geophysics Shahrood University of Technology Shahrood *** Iran Division of Operation and Maintenance Engineering Lulea University of Technology Lulea 97187 Sweden

The reliability and maintainability of electrical system of drum shearer at Parvade. 1 Coal Mine in central Iran was analyzed. The maintenance and failure data were collected during 19 months of shearer operation. According to trend and serial correlation tests, the data were independent and identically distributed （iid） and therefore the statistical techniques were used for modeling. The data analysis show that the time between failures （TBF） and time to repair （TTR） data obey the lognormal and Weibull 3 parameters distribution respectively. Reliability-based preventive maintenance time intervals for electrical system of the drum shearer were calculated with regard to reliability plot. The reliability-based maintenance intervals for 90%, 80%, 70% and 50% reliability level are respectively 9.91, 17.96, 27.56 and 56.1 h. Also the calculations show that time to repair （TTR） of this system varies in range 0.17-4 h with 1.002 h as mean time to repair （MTTR）. There is a 80% chance that the electrical system of shearer of Parvade. 1 mine repair will be accomplished within 1.45 h.

关键词： drum shearer electrical system reliabilitv maintenance

Reliability modeling of hydraulic system of drum shearer machine

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Journal of Coal Science & Engineering(China) 2011年第4期17卷 450-456页

作者： SEYED HADI Hoseinie MOHAMMAD Ataie REZA Khalookakaei uday kumar Faculty of Mining Petroleum ＆ Geophysics Shahrood University of Technology Shahrood *** Iran Division of Operation and Maintenance Engineering Lulea University of Technology Lulea 97187 Sweden

The hydraulic system plays an important role in supplying power and its transition to other working parts of a coal shearer machine. In this paper, the reliability of the hydraulic system of a drum shearer was analyzed. A case study was done in the Tabas Coal Mine in Iran for failure data collection. The results of the statistical analysis show that the time between failures （TBF） data of this system followed the 3-parameters Weibull distribution. There is about a 54% chance that the hydraulic system of the drum shearer will not fail for the first 50 h of operation. The developed model shows that the reliability of the hydraulic system reduces to a zero value after approximately 1 650 hours of operation. The failure rate of this system decreases when time increases. Therefore, corrective maintenance （run-to-t^ailure） was selected as the best maintenance strategy for it.

关键词： reliability modeling hydraulic system drum shearer maintenance strategy