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1Settling characteristics of ultrafine iron ore slimes显示文摘The slurry settling characteristics are the most important to design a thickener in process industries. In this work, the iron ore slurry from the screw classifier overflow was used for the settling study. It was observed that the original slurry exhibited a low settling velocity and a turbid supernatant during the settling process. Commercial flocculating agents with anionic, cationic, and nonionic characters were used to improve the settling behavior of suspensions, which were added into the slurry at different ranges of slurry pH values, respectively. The settling results show that the use of flocculants increase the settling rate by several times. Compared with the cationic and non-ionic flocculants, the anionic flocculant is more effective in enhancing the slurry settling rate. The small dose of the anionic flocculant is found to be more effective, but the other flocculants are less effective even at higher dosages. The simulation of an industrial thickener was carried out based on the laboratory settling data, and the appropriate design and selection parameters of the industrial thickener were estimated.Chinthapudi Eswaraiah Surendra Kumar Biswal Barada Kanta Mishra 2012International Journal of Minerals,Metallurgy and Materials2012,19,2:28
2Pathogenic mechanisms of pancreatitis显示文摘Pancreatitis is inflammation of pancreas and caused by a number of factors including pancreatic duct obstruction, alcoholism, and mutation in the cationic trypsinogen gene. Pancreatitis is represented as acute pancreatitis with acute inflammatory responses and; chronic pan-creatitis characterized by marked stroma formation with a high number of infiltrating granulocytes(such as neutrophils, eosinophils), monocytes, macrophages and pancreatic stellate cells(PSCs). These inflammatory cells are known to play a central role in initiating and promoting inflammation including pancreatic fibrosis, i.e., a major risk factor for pancreatic cancer. A number of inflammatory cytokines are known to involve in pro-moting pancreatic pathogenesis that lead pancreatic fibrosis. Pancreatic fibrosis is a dynamic phenomenon that requires an intricate network of several autocrine and paracrine signaling pathways. In this review, we have provided the details of various cytokines and molecular mechanistic pathways(i.e., Transforming growth factor-β/SMAD, mitogen--activated protein kinases, Rho kinase, Janus kinase/signal transducers and activators, and phosphatidylinositol 3 kinase) that have a critical role in the activation of PSCs to promote chronic pancreatitis and trigger the phenomenon of pancreatic fibrogenesis. In this review of literature, we discuss the involvement of several pro-inflammatory and anti-inflammatory cytokines, such as in interleukin(IL)-1, IL-1β, IL-6, IL--8 IL-10, IL-18, IL--33 and tumor necrosis factor-α, in the pathogenesis of disease. Our review also highlights the significance of several experimental animal models that have an important role in dissecting the mechanistic pathways operating in the development of chronic pancreatitis, including pancreatic fibrosis. Additionally, we provided several intermediary molecules that are involved in major signaling pathways that might provide target molecules for future therapeutic treatment strategies for pancreatic pathogenesis.Murli Manohar Alok Kumar Verma Sathisha Upparahalli Venkateshaiah Nathan L Sanders Anil Mishra 2017World Journal of Gastrointestinal Pharmacology and Therapeutics2017,8,1:21
3柑桔黄龙病的可见-近红外光谱特征显示文摘柑桔黄龙病是一种以木虱为载体的细菌病原,目前还没有行之有效的治疗方法,对世界柑桔产业构成了严重的威胁。探索快速检测柑桔黄龙病的方法,对该病的诊断、评估及进一步的控制都具有重要意义。该研究采用了快速、无损的光谱方法对该病害特征进行初步探索。实验针对健康及染病植株的叶片及冠层,分别在实验室条件及田间环境下测量了其可见-近红外光谱反射率,以分析寻找二者的光谱差异。对原始光谱数据进行了平滑、聚类平均等预处理,并求取了一阶微分以确定其红边位置(red edge position,REP)。为了应对一阶微分在REP处的多个波峰现象,采用了线性外插值法及拉格朗日插值法量化REP。研究结果显示,健康及染病样本的反射率在可见光、近红外具有明显的差异。相比于健康样本,染病样本因其呈现的黄化现象,使其反射率在可见光区较高;又因黄龙病菌会明显阻碍叶片对水分的吸收而使其反射率在近红外较低。REP同样显示了潜在的区分能力,其明显随着染病程度的加深逐渐向红波段移动。在染病程度差异较大的数据集中,REP平均值相差达20nm;而在染病程度差异较小的数据集中,阈值分割法的分类精度也高达90%以上,且线性外插值法的分类精度略高于拉格朗日插值法。本研究成果为利用光谱技术快速无损检测柑桔黄龙病提供了可靠的理论依据。李修华 李民赞 Won Suk Lee Reza Ehsani Ashish Ratn Mishra 2014光谱学与光谱分析2014,34,6:20
4Antihyperglycemic activity,antihyperlipedemic activity,haematological effects and histopathological analysis of Sapindus mukorossi Gaerten fruits in streptozotocin induced diabetic rats显示文摘Objective:To investigate the antihyperglycemic and antihyperlipidemie properties of hydroalcoholic extract of fruits of Sapindus mukorossi Caerlen and its beneficial effect on haeniatological parameters with histopathological analysis in streptpzotocin induced diabetic rats.Methods:Sapindus mukorossi fruits extract(250 and 500 mg/kg body weight) and standard drug glybenclamide(0.5 mg/kg body weight) were administered to diabetic rats.Effect of extract on hyperglycemia,hyperlipidemia and hematological parameters was studied in diabetic rats.Histopathological changes in diabetic rat pancreas were also observed after extract and glybenclamide treatment.Results:Daily oral administration of Sapindus mukorossi fruits extract(250 and 500 mg/kg body weight) and glybenclamide for 20 days showed beneficial effects on blood glucose level(P<0.01) and lipid level.The extract has a favorable effect on the histopathological changes of the pancreas in streptozotocin induced diabetes.Conclusions: These findings reveal that the hydroalcoholic extract of Sapindus mukorossi fruits extract possesses antihyperglycemic and antihyperlipidemie properties.In addition.the extract can prevent various complications of diabetes and improve some haeniatological parameters.Neeraj Verma G Amresh P K Sahu Neelam Mishra Anil P Singh Ch V Rao 2012Asian Pacific Journal of Tropical Medicine2012,5,7:14
5A randomized controlled trial of omega-3 fatty acids in dry eye syndrome显示文摘AIM:To evaluate the role of dietary supplementation of omega-3 fatty acids in dry eye syndrome.METHODS:A prospective,interventional,placebo controlled,double blind randomized trial was done at two referral eye centers.Two hundred and sixty-four eyes of patients with dry eye were randomized to receive one capsule(500mg)two times a day containing 325mg EPA and 175mg DHA for 3 months(omega-3 group).The omega-3 group was compared to a group of patients(n=254)who received a placebo(placebo group).There were 4 patient visits(at baseline,1 month,2 months and3 months).On each visit,recording of corrected distance visual acuity(CDVA),slit lamp examination and questionnaire based symptom evaluation and scoring was done.A symptomatic score of 0-6 was mild,6.1-12moderate and 12.1-18 severe dry eye.Response to intervention was monitored by routine tear function tests like Schirmer I test,tear film break-up time(TBUT),Rose Bengal staining and most notably,conjunctival impression cytology.RESULTS:Sixty-five percent of patients in the omega-3group and 33%of patients in placebo group had significant improvement in symptoms at 3 months(P=0.005).There was a significant change in both Schirmer's test value and TBUT values in the omega-3group(P<0.001),both comparisons.However,there was a larger drift in TBUT values in omega-3 than the placebo group,in comparison to Schirmer's test values.The mean TBUT score was 2.54±2.34 in the omega-3group and 0.13±0.16 in placebo group,respectively.The mean reduction in symptom score in omega-3 group was 2.02±0.96 as compared to 0.48±0.22 in placebogroup(P<0.001).Despite a slight increase mean score,the Schirmer scores did not correlate well with symptomatic improvement.CONCLUSION:Omega-3 fatty acids have a definite role for dry eye syndrome.The benefit seems to be more marked in conditions such as blepharitis and meibomian gland disease.The role of omega fatty acids in tear production and secretion needs further evaluation.Rahul Bhargava Prachi Kumar Manjushrii Kumar Namrata Mehra Anurag Mishra 2013International Journal of Ophthalmology(English edition)2013,6,6:14
6Improving Multimodel Weather Forecast of Monsoon Rain Over China Using FSU Superensemble显示文摘In this paper we present the current capabilities for numerical weather prediction of precipitation over China using a suite of ten multimodels and our superensemble based forecasts. Our suite of models includes the operational suite selected by NCARs TIGGE archives for the THORPEX Program. These are: ECMWF, UKMO, JMA, NCEP, CMA, CMC, BOM, MF, KMA and the CPTEC models. The superensemble strategy includes a training and a forecasts phase, for these the periods chosen for this study include the months February through September for the years 2007 and 2008. This paper addresses precipitation forecasts for the medium range i.e. Days 1 to 3 and extending out to Day 10 of forecasts using this suite of global models. For training and forecasts validations we have made use of an advanced TRMM satellite based rainfall product. We make use of standard metrics for forecast validations that include the RMS errors, spatial correlations and the equitable threat scores. The results of skill forecasts of precipitation clearly demonstrate that it is possible to obtain higher skills for precipitation forecasts for Days 1 through 3 of forecasts from the use of the multimodel superensemble as compared to the best model of this suite. Between Days 4 to 10 it is possible to have very high skills from the multimodel superensemble for the RMS error of precipitation. Those skills are shown for a global belt and especially over China. Phenomenologically this product was also found very useful for precipitation forecasts for the Onset of the South China Sea monsoon, the life cycle of the mei-yu rains and post typhoon landfall heavy rains and flood events. The higher skills of the multimodel superensemble make it a very useful product for such real time events.T. N. KRISHNAMURTI A. D. SAGADEVAN A. CHAKRABORTY A. K. MISHRA A. SIMON 2009Advances in Atmospheric Sciences2009,26,5:12
7Contribution of epigenetics in diabetic retinopathy显示文摘Diabetes has become the epidemic of the 21 st century, and with over 90% patients with diabetes becoming at a risk of developing retinopathy, diabetic retinopathy has emerged as a major public health concern. In spite of cutting edge research in the field, how retina and its vasculature are damaged by the diabetic milieu remains ambiguous. The environmental factors, life style or disease process can also bring in modifications in the DNA, and these epigenetic modifications either silence or activate a gene without altering the DNA sequence. Diabetic environment up- or downregulates a number of genes in the retina, and emerging research has shown that it also facilitates epigenetic modifications. In the pathogenesis of diabetic retinopathy, the genes associated with important enzymes(e.g., mitochondrial superoxide dismutase, matrix metalloproteinase-9 and thioredoxin interacting protein) and transcriptional factors are epigenetically modified, the enzymes responsible for these epigenetic modifications are either activated or inhibited, and the levels of micro RNAs are altered. With epigenetic modifications taking an important place in diabetic retinopathy, it is now becoming critical to evaluate these modifications, and understand their impact on this slow progressing blinding disease.KOWLURU Renu A. MISHRA Manish 2015Science China(Life Sciences)2015,58,6:12
8集合系统CT三维重建精准指导经皮肾镜手术目标肾盏选择和穿刺的临床研究显示文摘目的探讨集合系统CT三维重建帮助经皮肾镜手术(PCNL)精准进行目标肾盏选择和目标肾盏穿刺的可行性和安全性。方法肾结石PCNL患者196例,均行术前腹部泌尿系平片(KUB)、静脉肾盂造影(IVU)、CT平扫和增强扫描,分别获取肾结石、集合系统及肾脏周围器官的CT三维影像,在集合系统三维重建后面观影像上确定最佳PCNL目标肾盏,将确定的目标肾盏通过影像转化技术标识在IVU影像上,C臂机引导下穿刺该目标肾盏建立手术通道。结果所有PCNL手术均按术前的规划实现了精准穿刺目标肾盏建立手术通道,196例患者术中、术后无严重出血、邻近器官损伤等并发症,均未输血。鹿角形肾结石手术无石率为88%,肾盂肾盏结石94.1%。结论通过对影像的技术转化,将CT集合系统三维重建确定的目标肾盏准确标识在IVU影像上,指导PCNL术中对目标肾盏进行精准选择和精准穿刺,建立更加安全的手术通道,最大程度降低PCNL出血和器官损伤等并发症。李炯明 王光 刘建和 姜永明 张劲松 方克伟 石鑫 Prashant Mishra 2017临床外科杂志2017,25,2:12
9Cytotoxicity evaluation and hepatoprotective potential of bioassay guided fractions from Feronia limmonia Linn leaf显示文摘Objective:To evaluate the cytotoxicity and hepatoprotective potentials of extracts,fractions or isolated compound from the leaves of Feronia limonia(F.limonia).Methods:Qualitative phytochemical analysis of extracts,fractions or compound was performed by means of thin layer chromatography and spectroscopic assays.The%purity of compound was measured by analytical HPLC.Extracts,fractions or compound have been individually evaluated for their cytotoxicity effects(10,20,100,250,500,750 and 1 000 μg/mL).Based on the inhibitory concentration(IC_(50)) obtained from the cell viability assay,graded concentrations of extracts,fractions or isolated compound were assessed(10,20,50,100,200 μg/mL) for its hepatoprotective potential against CCl_4-induced hepatotoxicity by monitoring activity levels of serum glutamatic pyruvatic transaminase(SGPT) and serum glutamic oxaloacetic transaminase(SGOT).Results:Results indicated that the methanol extract of F.limonia was non-toxic and hepatoprotective in nature as compared with the petroleum ether extract.The acetone fraction of methanolic extract also showed similar properties but the subsequent two fractions were cytotoxic.However,the pure compound isolated from the penultimate fraction of methanolic extract was non-toxic and hepatoprotective in nature.Biochemical investigations(SCOT,SCPT) further corroborated these cytological observations.Conclusions:It can be concluded from this study that F.limonia methanol extract,some fractions and pure isolated compound herein exhibit hepatoprotective activity.However,cytotoxicity recorded in the penultimate fraction and investigation of structural details of pure compound warrants further study.Mahendra Jain Rakhee Kapadia Ravirajsinh N Jadeja Menaka C Thounaojam Ranjitsinh V Devkar SH Mishra 2011Asian Pacific Journal of Tropical Biomedicine2011,1,6:11
10The role and significance of Magnesium in modern day research-A review显示文摘Magnesium is one of the largely available elements in the earth’s crust. It has a low structural density with high specific strength. This unique material property has forced an increase in the use of magnesium and its alloys in various applications pertaining to industrial sector,automobiles, aerospace and biomedical. Since magnesium is a highly reactive metal, it is prone to higher rate of corrosion as compared to its counterparts. Thus, it is essential to analyze the corrosion behavior of magnesium and its alloys in its applications. An appropriate process is to be followed in the design and development of magnesium alloys which overcome the limitations of magnesium and enhance the desired material properties in accordance to their applications. This review paper summarizes the importance of magnesium and its material properties. The influence of various alloying elements on the mechanical properties of magnesium is reviewed. The broad classification of Mg alloys and their behavioral trends are detailed. The corrosion behavior of magnesium and the influence of corrosion products on the material characteristics of magnesium, in aqueous medium, are discussed. The manufacturing techniques of magnesium alloys along with the secondary techniques are also covered. The various applications and the limitations of magnesium in these applications are covered. A complete section is dedicated towards detailing the recent trends of magnesium(Mg) alloys, i.e., the biodegradable nature and applications of Mg alloys. The influence of biocorrosion on Mg alloys and techniques to overcome it have been deliberated. This paper provides a thorough review on recent developments of magnesium with respect to engineering applications.S V Satya Prasad S B Prasad Kartikey Verma Raghvendra Kumar Mishra Vikas Kumar Subhash Singh 2022Journal of Magnesium and Alloys2022,10,1:11
11A kinetic study on pyrolysis and combustion characteristics of oil cakes: Effect of cellulose and lignin content显示文摘Pyrolysis and combustion characteristics of three different oil cakes such as Pongamia(Pongamia Pinnata),Madhuca(Madhuca Indica),and Jatropha(Jatropha curcas) were investigated in this study.The cellulose and lignin contents of oil cakes play very important role in pyrolysis and combustion processes.A kinetic investigation of three oil cakes was carried out and major part of the samples decomposed between 210℃ and 500℃.Pyrolysis and combustion were carried out with the mixtures of cellulose and lignin chemicals in different ratios and compared with the oil cakes.The biomass with higher cellulose content showed faster rate of pyrolysis than the biomass with higher lignin content.However at higher temperatures(>600℃) all the oil cakes exhibited similar conversion at low heating rate in N2 atmosphere.Apparent activation energies increased for Madhuca and Pongamia oil cakes indicating the presence of more cellulose whereas,low activation energy of Jatropha confirms more lignin content.Ramakrishna Gottipati Susmita Mishra 2011燃料化学学报2011,39,4:10
12中性粒细胞明胶酶相关脂质运载蛋白作为心脏手术后急性肾脏损害的一种生物指标Mishra J. Dent C. Tarabishi R. P. Devarajan 朱冰坡 2005世界核心医学期刊文摘(心脏病学分册)2005,0,11:9
13Autochthonous halotolerant plant growth-promoting rhizobacteria promote bacoside A yield of Bacopa monnieri(L.)Nash and phytoextraction of salt-affected soil显示文摘Phytoremediation is a promising approach for reclamation of salt-affected soil.Phytoextraction is the most commonly used process,which exploits plants to absorb,immobilize,and accumulate salt in their shoots.In this study,halotolerant plant growth-promoting rhizobacteria(PGPR)were isolated from the rhizosphere of wild grasses growing naturally in salt-affected areas of Lucknow,Uttar Pradesh(India)and were tested for their efficacies of salt-tolerance and plant growth-promoting(PGP)abilities.Based on 16S rRNA sequences,the most efficient halotolerant isolates possessing PGP traits were identified as Pseudomonas plecoglossicida(KM 233646),Acinetobacter calcoaceticus(KM 233647),Bacillus flexus(KM 233648),and Bacillus safensis(KM 233652).Application of these isolates as bio-inoculants significantly(P<0.05)increased the growth and bacoside A yield of a medicinal plant,Bacopa monnieri(L.)Nash,grown on natural salt-affected soil.The phytoremediation of salt-affected soil was evident by the substantial increase in shoot Na^+:K^+ratio of bio-inoculant-treated plants.When compared to un-inoculated control plants,the soil physico-chemical properties of bio-inoculant-treated plants were improved.The shoot and root biomass(fresh and dry weights),soil enzymes,and soil nutrient parameters showed significant positive correlations with the shoot Na+:K+ratio.Consequently,the halotolerant PGPR screened in this study could be useful for the reclamation of saline soils concomitant with improved plant growth and bacoside A yield.Umesh PANKAJ Durgesh Narain SINGH Pooja MISHRA Pooja GAUR C.S.Vivek BABU Karuna SHANKER Rajesh Kumar VERMA 2020Pedosphere2020,30,5:9
14Mechanical Properties of ZnO Nanowires Under Different Loading Modes显示文摘A systematic experimental and theoretical investigation of the elastic and failure properties of ZnO nanowires (NWs) under different loading modes has been carried out. In situ scanning electron microscopy (SEM) tension and buckling tests on single ZnO NWs along the polar direction [0001] were conducted. Both tensile modulus (from tension) and bending modulus (from buckling) were found to increase as the NW diameter decreased from 80 to 20 nm. The bending modulus increased more rapidly than the tensile modulus, which demonstrates that the elasticity size effects in ZnO NWs are mainly due to surface stiffening. Two models based on continuum mechanics were able to fit the experimental data very well. The tension experiments showed that fracture strain and strength of ZnO NWs increased as the NW diameter decreased. The excellent resilience of ZnO NWs is advantageous for their applications in nanoscale actuation, sensing, and energy conversion.Feng Xu Qingqun Qin Ashish Mishra Yi Gu Yong Zhu 2010Nano Research2010,3,4:8
15Microstructural relation of macerals with mineral matter in coals from Ib valley and Umaria, Son-Mahanadi basin, India显示文摘Vivek Mishra K. N. Singh 2017International Journal of Coal Science & Technology2017,4,2:8
16Changes in organic structure and mineral phases transformation of coal during heat treatment on laboratory scale显示文摘Vivek Mishra Mamta Sharma Sanchita Chakravarty Amit Banerjee 2016International Journal of Coal Science & Technology2016,3,4:8
17Green Tourism in Mountain Regions-Reducing Vulnerability and Promoting People and Place Centric Development in the Himalayas显示文摘In recent years, mountain regions are attracting great attention to Indian tourists in general and foreign tourists in particular. The potential mountain resources for promoting green tourism are enormous in the form of natural and cultural heritage such as biosphere reserves, flora and fauna, lakes and rivers and traditional rural resources. In order to utilise tourism industry market, uncontrolled numbers of tourists and related haphazard infrastructural facilities in the vulnerable mountain regions pose serious environmental implications. The ecological pressures are threatening land, water and wild life resources through direct and indirect environmental impacts together with generation of solid and liquid wastes, so green tourism is emerging as an important task in order to develop new relationship between communities, government agencies and private sectors. The strategy focuses on ecological understanding, environmental protection and ecodevelopment. The major attributes of the green tourism include environmental conservation and education and distribution of income to local people based on strong partnership. Various knowledge systems go a long way for achieving the goals of the green tourism, which creates awareness about the value of environmental resources. Mountains have ecological, recreational, educational and scientific values, which need to be utilised in sustainable way. Various tourist activities and facilities need to be diversified in order to achieve multiple benefits including scientific field excursion, recreation in natural and cultural areas, community festivals and sport tourisms. Green tourism considers tourism development as an integral part of a national and regional development. The paper discusses the social, economic and environmental dimensions of the green tourism with particular reference to village tourism development programme taking empirical evidences from the Himalaya. Such programme also minimises biophysical and human vulnerability and risks in mountain regions. The environmental consciousness campaign and introduction of code through multi- purpose Tourist Resource Centres are gaining currency in above context.R. B. Singh D. K. Mishra 2004Journal of Mountain Science2004,1,1:8
18Current Status of Conventional and Molecular Interventions for Blast Resistance in Rice显示文摘Pyricularia oryzae anamorph of Magnaporthe oryzae is one of the most notorious fungal pathogens causing severe economic loss in rice production worldwide. Various methods, viz. cultural, biological and molecular approaches, are utilized to counteract this pathogen. Moreover, some tolerant or resistant rice varieties have been developed with the help of breeding programmes. Isolation and molecular characterization of different blast resistance genes now open the gate for new possibilities to elucidate the actual allelic variants of these genes via various molecular breeding and transgenic approaches. However, the behavioral pattern of this fungus breakups the resistance barriers in the resistant or tolerant rice varieties. This host-pathogen barrier will be possibly countered in future research by comparative genomics data from available genome sequence data of rice and M. oryzae for durable resistance. Present review emphasized fascinating recent updates, new molecular breeding approaches, transgenic and genomics approaches(i.e. mi RNA and genome editing) for the management of blast disease in rice. The updated information will be helpful for the durable, resistance breeding programme in rice against blast pathogen.Deepti SRIVASTAVA Md SHAMIM Mahesh KUMAR Anurag MISHRA Pramila PANDEY Deepak KUMAR Prashant YADAV Mohammed Harrish SIDDIQUI Kapildeo Narayan SINGH 2017Rice science2017,24,6:8
19PI3K signaling pathway targeting by using different molecular approaches to treat cancer显示文摘Recent evidence of research has been proposed that the phosphoinositide 3-kinase(PI3K) pathway is noticeable target for searching novel anticancer agents. The phosphoinositide 3-kinase(PI3K) is accountable for harmonizing a diverse range of cell functions, such as transcription, proliferation, cell survival, cell growth, degranulation, vesicular trafficking and cell migration, which are mostly involved in carcinogenesis. Particularly, PI3K-mediated signaling molecules and its effects on gene expression contribute to tumorigenesis. PI3Ks generally are grouped into three distinct classes: Ⅰ, Ⅱ and Ⅲ according to their structure and function. The class IA of PI3K includes an alpha, beta or delta p110 catalytic subunit(p110α, p110β, or p110γ), which are associated with the activation of RTKs. Mutations in PIK3CA, the gene encoding the p110α catalytic subunit of PI3K, have just been recognized as novel mechanisms of inducing oncogenic PI3K signaling. Therefore, the class IA PI3K is the only one of most evidently implicated in cancer. The PI3K pathway is mostly mutated in more cancer patients compared with normal person, making it an eyecatching molecular target for analyses based on inhibitor molecule. In this article, we highlighted the signaling effects and regulation pathway of PI3K involved in the development and survival of tumor cells. The consequence and intricacy of PI3K pathway made it an essential beneficial target for cancer treatment.Mohammad Rashid Shahid Karim Babar Ali Shamshir Khan Makhmur Ahmad Asif Husain Ravinesh Mishra 2017Journal of Chinese Pharmaceutical Sciences2017,26,9:7
20Solvent extraction of neodymium(Ⅲ) from acidic nitrate medium using Cyanex 921 in kerosene显示文摘The extraction of neodymium(Ⅲ) from acidic nitrate medium was investigated using Cyanex 921 as extractant in kerosene. The metal concentration in the aqueous phase before and after extraction was determined spectrophotometrically by Arsenazo Ⅲ method. The complete equilibration was achieved in 15 min. The effects of shaking time, nitric acid concentration, nitrate concentration, extractant concentration, and temperature on the extraction were studied. The extraction of Nd(Ⅲ) was found to increase very slowly with increase in concentration of HNO3 in the range of 0.001-0.008 mol/L and then decreased when 0.01 mol/L HNO3 was used. The percentage of extraction was increased with increase in nitrate concentration from 0.01-0.45 mol/L and then decreased when nitrate concentration increased to 0.5 mol/L. Quantitative extraction of Nd(Ⅲ) (98%) was obtained from the aqueous phase containing 0.001 mol/L HNO3 and 0.1 mol/L KNO3 using 0.5 mol/L Cyanex 921. On the basis of slope analysis, the extracted complex in the organic phase was proposed to be Nd(NO3)3.2Cyanex 921. The extraction of Nd(III) was found to increase with increase in concentration of metal ion in the range of 0.001-0.05 mol/L from 0.001 mol/L HNO3 and 0.1 mol/L KNO3 with 0.1 mol/L Cyanex 921. The percentage of extraction of neodymium was found to decrease with increase in temperature. From temperature variation studies, the negative value of △H indicated the extraction reaction to be exothermic and the negative value of △S indicated the formation of a stable complex. Almost 100% Nd(Ⅲ) was recovered from the fully loaded organic phase using 0.002 mol/L H2SO4 and 0.01 mol/L HCl.Nandita Panda Niharbala Devi Sujata Mishra 2012Journal of Rare Earths2012,30,8:7
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