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Effects of Sr^(2+) substitution on the structural, dielectric, and piezoelectric properties of PZT-PMN ceramics

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international Journal of Minerals,Metallurgy and Materials 2014年第2期21卷 175-180页

作者： Arvind Kumar S.K. Mishra research and Technology development centre Sharda University

This study described the structural, dielectric, and piezoelectric behavior of Pb1-xSrx[（Zr0.52Ti0.48）0.95（Mn1/3Nb2/3）0.05]O3 ceramics （PSZT-PMN, x=0, 0.025, 0.050, and 0.075）, prepared by a semi-wet route. X-ray diffraction, dielectric, and piezoelectric investigations were carried out to analyze the crystal structure. The relative dielectric constant and dielectric loss were both calculated as the functions of temperature. The room-temperature dielectric constant reaches a maximum for a Sr2＋-modified PZT-PMN ceramic with an x value of 0.050, which corresponds to the morphotropic phase boundary （MPB）. Raman spectroscopy studies also confirm the existence of this MPB for x=0.050. The piezoelectric strain coefficients （d33） value shows a maximum response for this composition. In addition, the phase transition temperature decreases significantly when the Sr2＋concentration increases in the PZT-PMN ceramics.

关键词： ceramic materials strontium substitution structural properties dielectric properties piezoelectricity

Effects of harvesting on productivity of bay leaf tree(Cinnamomum tamala Nees & Eberm):Case from Udayapur district of Nepal

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Journal of Forestry research 2014年第1期25卷 163-170页

作者： Dyutiman Choudhary S.P Kala N.P Todaria S.Dasgupta M.Kollmair international centre for Integrated Mountain development (ICIMOD) HNB Garhwal University

Cultivation of bay leaves （Cinnamomum tamalaNees ＆ Eberm） to fulfil household income needs is a long established practice in Udayapur district of Nepal. The practices adopted by farmers for bay leaf harvesting have not, however, been validated by scientific investigation for their sustainability. To investigate the impacts of harvesting on the yield of branch, leaves and biomass of leaves, a two-year research project was conducted in farm fields at Kopche village of Routa VDC in Udayapur district, Nepal. Four different harvesting treatments, the orien-tation and the order of branches were taken as independent variables to test their effects on number of branches, leaves and biomass of leaves. Orientation, harvesting treatments and order of branches had a significant effect on the number of branches, but not on the number of leaves or biomass （fresh and dry weight） of leaves in the year of harvest. Between two consecutive harvests there was no significant difference in the num-ber of branches, leaves or biomass. Lower two-thirds portion of the trees produced the largest number of leaves and branches of the fourth order in both years. Therefore, lower two-thirds portion of the trees were suitable for harvesting. Our findings support farmer experience that no change in productivity of leaves is observed when harvesting each year. For long term sustainability, harvesting should be conducted without debarking of trees or damage to branches. Our findings could be extrapolated to and tested in other areas with different access and user rights where the rota-tion for harvest is fixed or regulated without research evidence.

关键词： agro forestry tree leaf harvesting yield management practices sustainable development

Unravelling the linkages of cryosphere and mountain livelihood systems:A case study of Langtang,Nepal

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Advances in Climate Change research 2021年第1期12卷 119-131页

作者： Sabamee TULADHAR Binaya PASAKHALA Amina MAHARJAN Arabinda MISHRA international centre for Integrated Mountain development(ICIMOD) Kathmandu44703Nepal

Globally,mountains are often characterized as fragile and hazardous terrains,with vast areas covered by the *** livelihoods of communities in the Hindu Kush Himalayan region are closely linked with the *** over the past few decades,communities in the region have experienced multiple changes,including those driven by climat e change,with direct and immediate impacts on their lives and *** this study,we explore linkages between the cryosphere and high-mountain livelihoods using a social-ecological system *** examines how the complex social-ecological system in villages in Langtang Valley,Nepal,has evolved in response to both cryospheric and socioeconomic *** local communities perceive gradual but significant changes in the cryospheric system,such as receding and thinning glaciers,changing snowfall patterns,changes in temperature and precipitation patterns,and a growing incidence of cryosphere-related hazards,such as avalanches and *** in the Langtang Valley are also facing a number of socioeconomic changes,resulting in changing aspirations,particularly among the *** growing disconnection between society and the surrounding cryosphere,with direct impacts on the transfer and growth of local knowledge systems,are *** simultaneous changes in the cryosphere and the socioeconomic domain have also resulted in a homogenization of livelihood sources,with tourism emerging as the dominant source of *** has resulted in a dependence of the local population on food imported from outside the valley.A growing dependence on tourism for livelihoods,dependence on imports for food and other basic needs,and the lack of a risk reduction strategy might pose great risks for local lives and livelihoods in the long *** pertaining to diversifying livelihoods,harmonizing social capital,and hazard risk assessment are essential for strengthening linkages between cryosphere and the socioe

关键词： Cryosphere-livelihood linkages Social-ecological systems Climate change High-mountain communities Hindu Kush Himalaya Langtang Valley

Evaluating the impact of auxiliary fan practices on localised subsurface ventilation

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international Journal of Mining Science and Technology 2019年第6期29卷 933-941页

作者： David J.de Villiers Marc J.Mathews Philip Maré Marius Kleingeld Deon Arndt centre for research and Continued Engineering development North-West University

Mines are continually expanding in size and depth,leading to an increased reliance on localised subsurface ventilation *** use of underground auxiliary fans is a favoured method to increase and control airflow in working ***,the effectiveness of auxiliary fans in this regard is not *** paper evaluated the performance of these underground fan systems in four different South African deeplevel gold mines.A total auxiliary fan system efficiency of 5%was found across six systems,with the average fan efficiency of 33 fans at 38%.The results showed that these fans deviate significantly from their design operating ***,there are significant shortcomings in current underground fan *** detailed investigations led to the conclusion that the assemblage of underground auxiliary fan systems results in significant energy ***,maintaining good underground fan practice such as optimal fan selection,ducting design and maintenance is crucial for the efficacy of a mine ventilation network.

关键词： Mine ventilation Underground fan assemblage Fan system performance

More Accurate Climate Models for Better Prediction—The Case of the Precis Model in Burkina Faso,Ghana and Mali

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地学前缘 2009年第S1期16卷 101-102页

作者： Placide Beyon Hien Monica Idinoba Department of Environment and Sustainable development University of Ouagadougou centre for international Forestry research

West Africa is a region where not only the climate has seen some of the most dramatic changes but also climate models carry the greatest level of uncertainty. Designing an accurate climate model can be *** many cases,while the models may be relatively accurate at the global level,they show important discrepancies compared to reality when applied at a smaller *** the correct climate

关键词： rain West Africa climate rainfall

Reevaluating health metrics:Unraveling the limitations of disabilityadjusted life years as an indicator in disease burden assessment

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World Journal of Methodology 2025年第1期15卷 14-19页

作者： Ariel Beresniak Dominique Bremond-Gignac Danielle Dupont Gerard Duru Data Mining international Geneva 1216Switzerland Department of Ophtalmology Necker-Enfants Malades University HospitalAP-HPParis-CitéUniversityINSERMUMRS1138Team 17From Physiopathology of Ocular Diseases to Clinical DevelopmentSorbonne Paris CitéUniversityCentre de Recherche des CordeliersParis 75015France Data Mining America Montreal H2YCanada

In 1993,the World Bank released a global report on the efficacy of health promotion,introducing the disability-adjusted life years(DALY)as a novel *** DALY,a composite metric incorporating temporal and qualitative data,is grounded in preferences regarding disability *** review delineates the algorithm used to calculate the value of the proposed DALY synthetic indicator and elucidates key methodological challenges associated with its *** contrast to the quality-adjusted life years approach,derived from multi-attribute utility theory,the DALY stands as an independent synthetic indicator that adopts the assumptions of the Time Trade Off utility technique to define Disability *** to rely on no mathematical or economic theory,DALY users appear to have exempted themselves from verifying whether this indicator meets the classical properties required of all indicators,notably content validity,reliability,specificity,and *** DALY concept emerged primarily to facilitate comparisons of the health impacts of various diseases globally within the framework of the Global Burden of Disease initiative,leading to numerous publications in international *** widespread adoption,the DALY synthetic indicator has prompted significant methodological concerns since its inception,manifesting in inconsistent and non-reproducible *** the substantial diffusion of the DALY indicator and its critical role in health impact assessments,a reassessment is *** reconsideration is imperative for enhancing the robustness and reliability of public health decisionmaking processes.

关键词： Disability adjusted life years Cost-utility analyses Outcome research Public health Burden of disease

COVID-19 and beyond:how lessons and evidence from implementation research can benefit health systems’response and preparedness for COVID-19 and future epidemics

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Family Medicine and Community Health 2021年第4期9卷 5-9页

作者： Nafissatou Diop Montasser Kamal Marie Renaud Sana Naffa Global Health Division International Development Research CentreOttawaOntarioCanada

Early in the COVID-19 pandemic—and based on limited data on the novel coronavirus—it was projected that African countries will be ravaged and the health systems ***,Africa has so far defied these dire *** factors account for the less dramatic outcome,in particular the local know-how gained through dealing with previous epidemics,such as Ebola,and the early and coordinated political and public health response,applying a combination of containment and mitigation ***,these same measures,exacerbated by existing inequalities,have had negative impacts on vulnerable populations,notably women and ***,the observed deterioration of access to and provision of essential health services will likely continue and worsen in countries experiencing future waves of COVID-19 and lacking access to *** impact of the pandemic on health systems may be one of Africa’s main COVID-19 challenges and women and children its greatest *** this article,we argue that just as learning from previous epidemics and coordinated preparation informed Africa’s response to COVID-19,knowledge,innovations and resources from recent implementation research can be leveraged to mitigate the pandemic’s effects and inform recovery *** an example,we present the proven model and multifaceted approach of the Innovating for Maternal and Child Health in Africa Initiative and describe how such a model could be readily applied to building the robust and equitable systems needed to tackle future stresses and shocks,such as epidemics,on health systems while maintaining essential routine services.

关键词： COV services gained

Chemical leaching of an Indian bituminous coal and characterization of the products by vibrational spectroscopic techniques

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international Journal of Minerals,Metallurgy and Materials 2012年第4期19卷 279-283页

作者： B. Manoj A.G. Kunjomana Department of Physics Christ University research and development centre Bharathiar University

High volatile bituminous coal .was demineralized by a chemical method. The vibrations of the ＂aromatics＂ structure of graphite, crystalline or non-crystalline, were observed in the spectra at the 1600 cm-1 region. The band at 1477 cm-1 is assigned as VR band, the band at 1392 cm-1 as VL band and the band at 1540 cm-1 as GR band. Graphite structure remains after chemical leaching liberates oxygenated functional groups and mineral groups. The silicate bands between 1010 and 1100 cm-1 are active in the infrared （IR） spec^urn but inactive in the Raman spectrum. Absorption arising from C-H stretching in alkenes occurs in the region of 3000 to 2840 cm-~. Raman bands because of symmetric stretch of water molecules were also observed in the spectrum at 3250 cm-1 and 3450 cm-1. Scanning electron microscopy analy- sis revealed the presence of a graphite layer on the surface. Leaching of the sample with hydrofluoric acid decreases the mineral phase and increases the carbon content. The ash content is reduced by 84.5wt% with leaching from its initial value by mainly removing aluminum and silicate containing minerals.

关键词： bituminous coal characterization graphite leaching vibrational spectroscopy

Medical waste management in Iraq:a case study of Baghdad

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Waste Disposal and Sustainable Energy 2020年第4期2卷 329-335页

作者： Montazer K.Mensoor international Center for Training Research and Development(ICTRD)BaghdadIraq

There is a lack of information about medical waste management in *** study aims to monitor and evaluate the cur-rent situation of medical waste management in Baghdad as it represents the capital and the biggest populated city in *** 32%of hospitals are located in *** state-owned hospitals in Baghdad with the biggest bed capacity were *** study used structured interviews with staff in charge of waste management in the sampled hospitals to col-lect *** results showed that the generation rate of medical waste in the ten hospitals was 0.5 kg/(bed·day).The study also found that there were insufficient,ineffective,and improper isolation,collection,storing,processing,and safe disposal of medical wastes in the sampled public hospitals of *** study recommended that the Iraqi Ministry of Health takes extensive and quick effective measures to better monitor and evaluate medical waste management and provide ongoing training to personnel responsible for waste management in the hospitals.

关键词： Medical waste Waste management Hospitals Baghdad Iraq