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Vascular plants distribution in relation to topography and environmental variables in alpine zone of Kedarnath Wild Life Sanctuary,West Himalaya

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Journal of mountain Science 2018年第9期15卷 1936-1949页

作者： cHANDRA Sudeep SINGH Ankit SINGH c.P. nautiyal m.c. RAWAT L.S. High Altitude Plant Physiology Research centre(HAPPRc)H.N.B.Garhwal University Srinagar Garhwal-246174UttarakhandIndia Space Applications centre (Indian Space Research Organization)Ahmedabad 380015India Govind Ballabh Pant National Institute of Himalayan Environment&Sustainable Development Garhwal Unit Srinagar Garhwal-246174UttarakhandIndia

The present study was carried out in Tungnath alpine meadows of Kedarnath Wild Life Sanctuary, Western Himalaya from subalpine to upper alpine zone. A total of four summits were selected along an altitudinal gradient and sampled for detailed vegetation analysis using multi summit approach as per Global observation research initiative in alpine environments(GLORIA). Species richness, diversity, and evenness among four summits as well as the interaction between environmental variables with plant communities were assessed. monthly mean soil temperature was calculated using data retrieved from geo-precision temperature logger in order to identify the trend of soil temperature among different season and altitudinal gradient and its implications to plant communities. Soil samples were analyzed fromeach summit by collecting randomized composite soil samples. The indirect non-metric multidimensional scaling(NmDS) and direct canonical correspondence analysis(ccA) tools of ordination techniques to determine the linkage between plant species from various sample summits and biotic/abiotic environmental gradients were used in the present study. The results of the study demonstrated increase in species richness as soil temperature increases, the ecotone representing summits were found most warm summits followed by highest species richness. Annual soil temperature increased by 1.43°c at timberline ecotone. Whereas, at upper alpine zone the soil temperature increased by 0.810 c from year 2015 to 2016. S?rensen's similarity index was found to be increased between subalpine and upper alpine zone with increase in the presence of subalpine plant species at upper alpine zone. Both the ordination tools separate the subalpine summit and their respective vegetation from summits representingtimberline ecotone and upper alpine zone. Soil p H, altitude, soil cation exchange capacity were found as the key abiotic drivers for distribution of plant species.

关键词： GLORIA Non-metric multidimensionalscaling (NmDS) canonical correspondence analysis(ccA) Ecotone West Himalaya

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Hard rock tunnel boring m.c.ine penetration test as an indicator of chipping process efficiency

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Journal of Rock m.c.anics and Geotechnical Engineering 2017年第4期9卷 611-622页

作者： m.c. Villeneuve Department of Geological Sciences University of Canterbury Christchurch 8140 New Zealand

The transition from grinding to chipping can be observed in tunnel boring m.c.ine(TBm) penetration test data by plotting the penetration rate(distance/revolution) against the net cutter thrust(force per cutter) over the full range of penetration rates in the *** penetration test data to the geological and geom.c.anical characteristics of rock masses through which a penetration test is conducted provides the ability to reveal the efficiency of the chipping process in response to changing geological *** test data can also be used to identify stress-induced tunnel face *** research shows that the strength of the rock is an important parameter for controlling how m.c. net cutter thrust is required to transition from grinding to *** also shows that the geological characteristics of a rock will determine how efficient chipping occurs once it has *** particular,geological characteristics that lead to efficient fracture propagation,such as fabric and m.c. contents,will lead to efficient *** findings will enable a better correlation between TBm performance and geological conditions for use in TBm design,as a basis for contractual payments where penetration rate dominates the excavation cycle and in further academ.c.investigations into the TBm excavation process.

关键词： Penetration rate Grinding chipping Geological characteristics Face stability

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Photoluminescence upgradation of La_(2)mgTiO_(6):2%Dy^(3+) perovskite with monovalent(Li^(+)),divalent(Ba^(2+),Sr^(2+)) and trivalent(Bi^(3+),Sm^(3+))cation sensitization

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Journal of Rare Earths 2025年第1期43卷 47-56,I0002页

作者： V.P.Veena K.Arun c.K.Shilpa S.V.Jasira K.m.Nissamudeen School of Pure and Applied Physics Kannur UniversityPayyanur CampusEdatKannurKrala67 India Department of Nanoscience and Nanotechnology Kannur UniversityPayyanur CampusEdatkannurKerala670327India

Nano phosphors of 2%Dy^(3+)(wt%)doped La_(2)mgTiO_(6) and monovalent/divalent/trivalent co-doped La_(1.98)Dy_(0.02)mgTiO_(6):x%A^(y+)(A^(y+):Li+,Ba^(2+),Sr^(2+),Bi^(3+),and Sm^(3+);0≤x≤2 wt%)were synthesized by combustion *** the XRD data,it is deduced that an increase in the valency of co-dopant increases the crystallinity of the double perovskite orthorhombic nanocrystal *** an increase in co-dopant size,an elevation in optical bandgap is visible with the highest bandgap of 3.835 eV for Bi^(3+).The photo-absorption is monotonically broadened for Sr^(2+),Sm^(3+),and Li+around 200-450 ***351 nm,Dy^(3+)triggered lattice shows major characteristic emission peaks at 480 nm(^(4)F_(9/2)→^(6)H_(15/2)),574 nm(^(4)F_(9/2)→^(6)H_(13/2)),and 670 nm(^(4)F_(9/2)→^(6)H_(11/2)).leading to near white light emission with cIE coordinates(0.341,0.376).Upon co-doping,the PL intensity is significantly increased with maximum emission for trivalent Sm^(3+),followed by divalent Sr^(2+)and monovalent Li+*** increasing excitation wavelength,Sr^(2+)shows a dominated output and it is found that divalent Sr^(2+)is a potential codopant that could enhance luminescence intensity up to 6 times with a Sr^(2+)→Dy^(3+)energy transfer efficiency of 86%.It is specified that the cIE coordinates of Li+co-doped samples show ideal white emission with color coordinates(0.333,0.336).The concluding outcomes signify the noblest rare earth Sm^(3+)co-doping and thus Sm^(3+)→Dy^(3+)energy transfer m.c.anism is discussed in detail.

关键词： Photoluminescence Perovskite WLED co-doping Rareearths

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Spent coffee grounds as a renewable source of energy: An analysis of bulk powder flowability

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Particuology 2019年第2期17卷 92-100页

作者： L. massaro Sousa m.c. Ferreira Drying center for Pastes Suspensions and Seeds. Chemical Engineering Department Federal University of Sao Carlos. P.O. Box 676 13565-905 Sao Carlos Brazil

The main use for spent coffee grounds (ScG) produced in the soluble coffee industry is thermal energy generation in the industry itself. The ScG are processed using operations that are strongly dependent on powder flow behavior. In this study, we evaluated two classical flowability in dices of non-consolidated ScG powders: the angle of repose (AoR), and the Hausner ratio (HR). The influences of the mean particle diameter, particle size distribution (PSD), and water content on the AoR and HR values of ScG were analyzed for powders with a mean particle size range of 225-550 μm. For powders with a mean particle size close to 350 μm and for mixtures containing more than 40% fine particles, the HR (>1.35) and AoR (>45 °) values were characteristic of poor flowability. The AoR was sensitive to the powder PSD, and powders with similar mean particle sizes had higher AoR values when the PSD was larger. For powders w让h water contents up to 50%, the flowability indices were not greatly affected by the water content. A modified linear-mixture packing model was used to predict the packed bed void fractions for binary and ternary mixtures of the three base powders. The model was used to construct a ternary diagram to estimate the HR values of the mixtures. An equation was fitted to correlate HR and AoR. The proposed diagram and the equation provide insight into flow behavior and could be used for process design of industrial plants that handle ScG.

关键词： Spent coffee ground Biomass Flowability Hausner ratio Angle of repose

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THE EFFEcT OF BORON AND cARBON ADDITION ON WELDABILITY OF DS TmS-75 SUPERALLOY

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Acta metallurgica Sinica(English Letters) 2005年第1期18卷 24-32页

作者： m.c. chaturvedi N.L. Richards Department of m.c.anical and Industrial Engineering University of manitoba Winnipeg Manitoba R3T 5V6 CanadaDepartment of Mechanical and Industrial Engineering University of Manitoba Winnipeg Manitoba R3T 5V6 Canada

Four alloys TmS-75 (Base), Base+B, Base+c and TmD-103 (Base+B+c) with varying levels of B, c were directionally solidified (DS), and their weldability was investigated by bead-on-plate electron beam welding. It was found that cracking occurred in the weld-metal, as well as in the heat affected zone (HAZ). Both γ/γ' and/or γ/carbide eutectic contributed to the weld-metal cracking, and the γ/γ' eutectic was found to be mainly responsible for cracking in HAZ. However, constitutional liquation of carbides seems to have made some contribution also. The B addition had a detrimental effect on HAZ cracking susceptibility, while c addition improved it appreciably even in the presence of B. In addition, no obvious differences were observed in cracking susceptibility of weld-metal in the four alloys. The cracking modes and m.c.anisms underlying the effect of B and c addition on weldability could be explained on the basis of m.c.ostructures of the four alloys.

关键词： Ni-based superalloy low melting point constituents liquation cracking

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An illustrated guide to:Distributed and integrated fibreoptic sensing in seismology

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Earthquake Science 2025年第1期38卷 67-77页

作者： Andreas Fichtner Fabian Walter Patrick Paitz Sara Klaasen Daniel c.Bowden Sebastian Noe Nils müller Dominik Husmann Jacques morel Department of Earth Sciences ETH ZürichZürich 8049Switzerland Swiss Federal Institute for Forest Snow and Landscape ResearchBirmensdorf 8903Switzerland Swiss Federal Institute of metrology METAS Bern 3003Switzerland

The properties of laser signals are affected by deformation of the optical fibre through which they are *** this deformation dependence is undesirable in telecommunication,it can be exploited for the construction of novel seism.c.sensors that fill a niche in data acquisition where traditional seismometer arrays would be difficult to *** includes densely populated urban centers,the oceans,volcanoes and the Earth’s polar *** notes complement a presentation on recent methodological developments and applications in fibre-optic *** first part is focused on the use of distributed fibreoptic sensing in cryosphere research,and specifically the investigation of the internal structure and seism.c.ty of glaciers and ice *** second part is dedicated to recent advances in integrated fibre-optic sensing,with emphasis on novel measurement principles and sensitivity.

关键词： seismology fibre-optics cryosphere earthquakes

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Thermal characteristics in the cutting of Inconel 718 Superalloy Using cW Nd:YAG Laser

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Journal of materials Science & Technology 2010年第4期26卷 362-366页

作者： D.G. Ahn K.W. Byun m.c. Kang Department of m.c.anical Engineering Chosun University 375 Seosuk-dong Dong-gu Gwang-ju 501-759 Korea Hybrid materials Solution National core Research (NcRc) Pusan National University San 30 Changjeon-dong Keumjeong-gu Busan 609-735 Korea

The objective of the this study is to investigate the effects of cutting parameters on thermal characteristics, including practical cutting regions, the formation of the kerfwidth and the heat transfer phenomenon, in the cutting of Inconel 718 super-alloy sheets using a cW Nd：YAG laser. From the results of the experiments, the influence of process parameters on both the practical cutting region and the kerfwidth has been examined. In addition, it has been shown that the kerfwidth of the specimen lies in the range of 0.53-0.61 mm. In order to examine characteristics of the heat transfer during the laser cutting process, a three-dimensional quasi-steady heat transfer analysis has been performed using the commercial code SYSWELD V9.0. From the results of the analysis, the influence of cutting parameters on the temperature distribution in the vicinity of the cut section has been quantitatively evaluated. Based on these results, optimal cutting conditions have been estimated.

关键词： cW Nd:YAG laser Inconel 718 Kerfwidth Quasi-steady heat transfer analysis

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Towards cr（VI）-free anodization of aluminum alloys for aerospace adhesive bonding applications： A review

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Frontiers of chem.c.l Science and Engineering 2017年第3期11卷 465-482页

作者： Shoshan T. Abrahami John m.m. de Kok Herman Terryn Johannes m.c. mol materials innovation institute (m2i) 2628 XG Delft The Netherlands Delft University of Technology Department of Materials Science and Engineering 2628 CD Delft The Netherlands Fokker Aerostructures BV 3351 LB Papendrecht The Netherlands Department of materials and chemistry Research Group Electrochemical and Surface Engineering (SURF) Vrije Universiteit Brussel 1050 Brussels Belgium

For more than six decades, chrom.c.acid anodizing （cAA） has been the central process in the surface pre-treatment of aluminum for adhesively bonded aircraft structures. Unfortunately, this electrolyte contains hexavalent chromium （cr（VI））, a compound known for its toxicity and carcinogenic properties. To comply with the new strict international regulations, the cr（VI）-era will soon have to come to an end. Anodizing aluminum in acid electrolytes produces a self-ordered porous oxide layer. Although different acids can be used to create this type of structure, the excellent adhesion and corrosion resistance that is currently achieved by the complete cr（VI）-based process is not easily matched. This paper provides a critical overview and appraisal of proposed alternatives to cAA, including combinations of multiple anodizing steps, pre- and post anodizing treatments. The work is presented in terms of the modifications to the oxide properties, such as morphological features （e.g., pore size, barrier layer thickness） and surface chemistry, in order to evaluate the link between fundamental principles of adhesion and bond performance.

关键词： aluminum cr(VI)-free surface pre-treat- merits anodizing adhesive bonding

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Dispersal of invasive species by drifting

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current Zoology 2011年第6期57卷 818-827页

作者： m.c. VAN RIEL G. VAN DER VELDE A. BIJ DE VAATE Radboud University Nijmegen Institute for Water and Wetland Research Department of Animal Ecology and Ecophysiology Section Aquatic Animal Ecology Heyendaalseweg 135 6525 AJ Nijmegen The Netherlands Team Freshwater Ecology DLO-Alterra P.O. Box 47 6700 AA Wageningen The Netherlands Netherlands centre for Biodiversity Naturalis EO. Box 9517 2300 RA Leiden The Netherlands Waterfauna Hydrobiologisch Adviesbureau Oostrandpark 30 8212 AP Lelystad The Netherlands

Drifting can be an effective way for aquatic organisms to disperse and colonise new areas. Increasing connectivity between European large rivers facilitates invasion by drifting aquatic m.c.oinvertebrates. The present study shows that high abundances of invasive species drift in the headstream of the river Rhine. Dikerogammarus villosus and chelicorophium.c.r- vispinum represented up to 90% of the total of drifting m.c.oinvertebrates. Drift activity shows seasonal and diel patterns. most species started drifting in spring and were most abundant in the water column during the summer period. Drift activity was very low during the winter period. Diel patterns were apparent; most species, including D. villosus, drifted during the night. Drifting m.c.oinvertebrates colonised stony substrate directly from the water column. D. villosus generally colonised the substrate at night, while higher numbers of c. curvispinum.c.lonised the substrate during the day. It is very likely that drifting functions as a disper- sal m.c.anism for crustacean invaders. Once waterways are connected, these species are no longer necessarily dependent on dispersal vectors other than drift for extending their distribution range

关键词： Amphipods Invaders colonization Drift Daily rhythms Seasonal variation

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characteristics of life-form and growth-form of plant species in an alpine ecosystem of North-West Himalaya

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Journal of Forestry Research 2011年第4期22卷 501-506页

作者： R. K. Vashistha Neelam Rawat A. K. chaturvedi B. P. nautiyal P. Prasad m. c. nautiyal High Altitude Plant Physiology Research centre PO Box - 14 Hemwati Nandan Bahuguna Garhwal University Srinagar(A Central University) Srinagar-246174 Uttarakhand India High Altitude Plant Physiology Research centre PO Box - 14 Hemwati Nandan Bahuguna Garhwal University Srinagar (A Central University) Srinagar-246174 Uttarakhand India Department of Horticulture Aromatic and Medicinal Plants (HAMP) School of Earth Science and Natural Resources Management Mizoram University Tanhril-796 004 Aizawl India

The present study was conducted in the alpine pastures of Tungnath （30° 14＇ N and 79° 13＇ E） to observe life-form and growth-form patterns of alpine plant species under grazed and ungrazed conditions and to work out the plant life form spectrum. Species were categorized as plant habit, height and length of growth-cycle and life-form.c.asses according to Raunkiaer＇s system. The results show that in total of 68 species at grazed site, hem.c.yptophytes （He） accounted for 50.00% species, followed by cryptophytes （26.47%）, chamaephytes （16.18%）, phanemphytes （4.41%） and therophytes （2.94%）. At the ungrazed site in 65 plant species, hem.c.yptophytes （He） accounted fo＇r 49.23% species, cryptophytes （26.15%）, chamaephytes （15.38%）, phanerophytes （6.15%） and ther6phytes （3.08 % species）. In general, hem.c.ptophyte are dominant^in both sites i.e. graged and ungrazed. Growth form.c.tegories were classified as forbs, shrubs, grasses and sedges＇and undershrubs, according to plant habit and height. On the basis of length of the growth cycle, species were categorized as plant species of short growth cycle, intermediate growth cycle and long growth cycle. The short forbs of plant habit and height, had the highest emergence, and grasses and sedges had the lowest emergence in representative species. Percentage of species with long growth cycle was highest in both sites.

关键词： Alpine biological spectrum growth form Himalaya life

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