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Xylose: absorption, fermentation, and post-absorptive metabolism in the pig

Journal of Animal Science and Biotechnology 2018年第1期9卷 1-9页

作者： Nichole F.Huntley john F.Patience Department of Animal Science 213 Kildee HallIowa State University Department of Animal Science 201B Kildee HallIowa State University

Xylose, as β-1,4-linked xylan, makes up much of the hemicel ulose in cel wal s of cereal carbohydrates fed to pigs. As inclusion of fibrous ingredients in swine diets continues to increase, supplementation of carbohydrases, such as xylanase,is of interest. However, much progress is warranted to achieve consistent enzyme efficacy, including an improved understanding of the utilization and energetic contribution of xylanase hydrolysis product（i.e. xylooligosaccharides or monomeric xylose）. This review examines reports on xylose absorption and metabolism in the pig and identifies gaps in this knowledge that are essential to understanding the value of carbohydrase hydrolysis products in the nutrition of the pig. Xylose research in pigs was first reported in 1954, with only sporadic contributions since. Therefore, this review also discusses relevant xylose research in other monogastric species, including humans. In both pigs and poultry, increasing purified D-xylose inclusion general y results in linear decreases in performance, efficiency, and diet digestibility. However,supplementation levels studied thus far have ranged from 5% to 40%, while theoretical xylose release due to xylanase supplementation would be less than 4%. More than 95% of ingested D-xylose disappears before the terminal ileum but mechanisms of absorption have yet to be ful y elucidated. Some data support the hypothesis that mechanisms exist to handle low xylose concentrations but become overwhelmed as luminal concentrations increase. Very little is known about xylose metabolic utilization in vertebrates but it is wel recognized that a large proportion of dietary xylose appears in the urine and significantly decreases the metabolizable energy available from the diet. Nevertheless, evidence of labeled D-xylose-1-^（14）C appearing as expired^（14）co_2 in both humans and guinea pigs suggests that there is potential,although small, for xylose oxidation. It is yet to be determined if pigs develop increased xy

关键词： Pentose utilization Swine Threitol Xylose absorption Xylose metabolism

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Effect of Processing and composition on the Structure and Properties of P/M EP741NP Type Alloys

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Chinese Journal of Aeronautics 2007年第2期20卷 97-106页

作者： john Radavich Tadeu Carneiro David Furrer Joseph Lemsky Anthony Banik Micro-Met Laboratories 209 North Street W. Lafayette IN 47906 USA Reference Metals company 1000 Old Pond Road Bridgeville PA 15017 USA Rolls-Royce corporation PO Box 420 S/C-W05 Indianapolis IN 46206 USA Ladish co. Inc. PO Box 8902 Cudahy WI 53110 USA Special Metals 100 Industrial Lane Princeton KY 42445 USA

A study was carried out on the effects of processing and composition on the structure and properties of P/M EP741NP type alloys. The objectives of this study were to understand the role of Hf in a P/M superalloy containing high niobium used in aircraft engines and to determine the effects of extrusion and forging the powders as contrasted to HIPing （hot isostatic pressing） only. Two alloys of the P/M EP741NP composition were atomized： one alloy contained 0.26%Hfand the other was Hf free. After the as-atomized powders from both alloys were characterized, the powders were extruded into billets, forged and heat treated. After each process, the microstructures were characterized by SEM and the phases were extracted and identified by X-ray diffraction. The presence of Hf in the residues was probed by EDS （energy dispersive spectroscopy）. The alloys were given the published Russian heat treatment as well as a more conventional heat treatment more typical of western powder alloys. Tensile, creep and stress rupture mechanical property tests were run. Results of the structural behavior of the alloys after each processing step will be presented and discussed. The role of the Hfon the mechanical properties will be discussed.

关键词： P/M powder metallurgy X-ray diffraction EP741NP

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Hydrogen storage in a rare-earth perovskite-type oxide La_(0.6)Sr_(0.4)co_(0.2)Fe_(0.8)O_3 for battery applications

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Rare Metals 2018年第12期37卷 1003-1013页

作者： john Henao Oscar Sotelo Maura Casales-Diaz Lorenzo Martinez-Gomez coNACYT-CIATEQ A.C. Av. Manantiales 23-AParque Industrial Bernardo Quintana Instituto de Ciencias Fisicas (ICF) Universidad Nacional Autonoma de Mexico (UNAM)-Campus Morelos

Recently, rare-earth perovskite-type oxides with the general formula ABO(A rare earth element, B transition metal, O oxygen) are regarded as promising materials for Ni/oxide batteries due to their hydrogen storage ability. In the present study, the hydrogen storage properties of the rare-earth perovskite-type oxide LaSrcoFeOwere evaluated in alkaline solution and at various temperatures. The hydrogen storage properties were investigated electrochemically by applying galvanostatic charge/discharge currents. Electrochemical pressurecomposition-temperature isotherms were constructed using the Nernst equation. The exchange current density and proton hydrogen diffusion coefficient were calculated using linear polarization measurements and the potential-step method, respectively. Interestingly, the maximum hydrogen absorption capacity, re-calculated from the electrochemical capacity, is 1.72 wt% at 333 K and 6 mol·LKOH. In addition, the hysteresis value, calculated from pressure-composition-temperature isotherms, was429 J·molat 333 K,while the self-discharge rate was about 25% after 24-h storage at open circuit and at 333 K.

关键词： Hydrogen storage Rare earths Perovskites Ni/oxide batteries

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Space- and ground-based co_2 measurements： A review

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Science China Earth Sciences 2016年第11期59卷 2089-2097页

作者： YUE TianXiang ZHANG LiLi ZHAO MingWei WANG YiFu john WILSON State Key Laboratory of Resources and Environment Information System Institute of Geographical Science and Natural Resources Research Beijing 100101 China Jiangsu Center for collaborative Innovation in Geographical Information Resource Development and Application Nanjing 210046 China Anhui Center for collaborative Innovation in Geographical Information Integration and Application Chuzhou University Chuzhou 239012 China Spatial Sciences Institute University of Southern California Los Angles CA90089-0374 USA

The climate warming is mainly due to the increase in concentrations of anthropogenic greenhouse gases, of which co_2 is the most important one responsible for radiative forcing of the climate. In order to reduce the great estimation uncertainty of atmospheric co_2 concentrations, several co_2-related satellites have been successfully launched and many future greenhouse gas monitoring missions are planned. In this paper, we review the development of co_2 retrieval algorithms, spatial interpolation methods and ground observations. The main findings include: 1) current co_2 retrieval algorithms only partially account for atmospheric scattering effects; 2) the accurate estimation of the vertical profile of greenhouse gas concentrations is a long-term challenge for remote sensing techniques; 3) ground-based observations are too sparse to accurately infer co_2 concentrations on regional scales; and 4) accuracy is the primary challenge of satellite estimation of co_2 concentrations. These findings, taken as a whole, point to the need to develop a high accuracy method for simulation of carbon sources and sinks on the basis of the fundamental theorem of Earth's surface modelling, which is able to efficiently fuse space- and ground-based measurements on the one hand and work with atmospheric transport models on the other hand.

关键词： Accuracy Carbon satellites Retrieval algorithms Space-and ground-based measurements HASM

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New and interesting diatoms from the Shimen Wetwalls,Yunnan Province,China.Ⅱ.The diatom genus Nupela Vyverman&compère(Bacillariophyceae)

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Journal of Oceanology and Limnology 2023年第1期41卷 327-341页

作者： Qi LIU Xi LUO Shulian XIE john Patrick KOCIOLEK School of Life Science Shanxi UniversityTaiyuan 030006China Museum of Natural History University of ColoradoBoulderCO 80309USA Department of Ecology and Evolutionary Biology University of ColoradoBoulderCO 80309USA

We detailed the valve morphology of five new species of diatom genus Nupela from wetwall communities in Yunnan Province,China,with light and scanning electron *** five new species demonstrate great variability within the genus,as three of them are biraphid and two are *** addition,variation was noted in the structure of internal proximal raphe ends,with some species having anchor-shaped ends and other species have hooked *** genus Nupela has grown considerably in 30years since it was first proposed,going from a monotypic genus to over 85 *** of the genus is based on the presence of an external covering over the *** discussed the systematic placement of Nupela within the naviculoid *** Province appears to harbor many endemic diatom taxa,and many regions of the province have yet to be studied.

关键词： Nupela scanning electron microscope(SEM) Yunnan new species morphology China Bacillariophyceae

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Environmental impact improvements due to introducing automation into underground copper mines

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International Journal of Mining Science and Technology 2021年第6期31卷 1159-1167页

作者： Kyle Moreau corey Laamanen Ron Bose Helen Shang john Ashley Scott School of Engineering Laurentian UniversitySudburyON P3E 2C6Canada XPS–Glencore Greater SudburyON P0M 1S0Canada

A life-cycle assessment(LCA) model was developed to comparatively analyze the use of manual and automated mining equipment in underground copper mine *** and key variables that were determined to contribute to the environmental impact of operations were identified for six mine sites in a range of geographical locations around the *** model successfully calculated carbon dioxide(co_(2) eq.) emissions to within 4.9% of the reported annual emissions from the site's respective *** implementation of automation was found to decrease global warming potential by a range of 11.4%-18.0% or 3.9-17.9 kg co_(2) eq./t *** model was also used to estimate the average reductions across several impact potentials including,acidification(11.9%-17.8%),eutrophication(7.6%-13.7%),and human toxicity(16.0%-20.0%).World-wide the mining industry is moving toward introducing significantly more automation to enhance productivity and *** novel work demonstrates an important third dimension that can support this move,reduced environmental impact.

关键词： Automation Underground copper mines Environmental improvements Life cycle assessment Modelling

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Efficacy of praziquantel treatment regimens in pre-school and school aged children infected with schistosomiasis in sub-Saharan Africa:a systematic review

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Infectious Diseases of Poverty 2018年第1期7卷 723-729页

作者： Muhubiri Kabuyaya Moses john Chimbari Samson Mukaratirwa Discipline of Public Health Medicine Howard CollegeUniversity of KwaZulu-NatalP.O Box 4041DurbanSouth Africa college of Health Sciences University of KwaZulu-NatalDurbanSouth Africa School of Life Sciences University of KwaZulu-NatalDurbanSouth Africa

Background:Schistosomiasis is a serious public health burden in sub-Saharan *** is the only drug recommended by the World Health Organization to treat both urogenital and intestinal *** reliance on a single drug to treat a disease with such a huge burden has raised concerns of possible drug resistance mainly in endemic *** systematic review was conducted to identify gaps and recent progress on the efficacy of different regimens of praziquantel in treating schistosomiasis among children in sub-Saharan Africa where Schistosoma mansoni and *** are *** text:A literature search of peer-reviewed journals was done on Google Scholar,MEDLINE(under EBScohost)and PubMed databases using pre-defined search terms and Boolean *** search included studies published from 2008 to 2017(August)with emphasis on the efficacy of praziquantel on *** and *** infections among preschool and school *** publications satisfied the inclusion criteria for the *** studies reviewed were from 10 sub-Saharan African countries and 7/19 of the studies(37%)were conducted in *** studies(37%)focused on Schistosoma mansoni,6/19(31.5%)on *** and another 6 on mixed infection.A single standard dose of 40 mg/kg body weight was the most used regimen(9)followed by the repeated single standard dose assessed for efficacy at 3-4 weeks ***:A repeated standard dose of 40 mg/kg achieved satisfactory efficacy compared to a single dose against both parasite ***,findings on efficacy of repeated doses in co-infection of *** and *** were not *** administrated at 60 mg/kg was slightly more efficacious than the 40 mg/kg standard *** and transitory side-effects were reported for both *** review indicates that further investigations are necessary to conclusively determine efficacy of praziquantel on coinfection of ***

关键词： Praziquantel Efficacy Resistance Schistosoma mansoni Schistosoma haematobium Sub-Saharan Africa

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Oligomer saccharide reduction during dilute acid pretreatment co-catalyzed with Lewis acids on corn stover biomass

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International Journal of Agricultural and Biological Engineering 2013年第2期6卷 54-62页

作者： john Degenstein Srinivas Reddy Kamireddy Melvin PTucker Yun Ji Department of Chemical Engineering Purdue UniversityWest LafayetteIndiana 47907USA Department of Chemical Engineering University of North DakotaGrand ForksNorth Dakota 58202USA National Renewable Energy Laboratory GoldenColorado 80401USA

The dilute sulfuric acid pretreatment of lignocellulosic biomass is a well understood process that significantly enhances the yield of glucose after enzymatic *** goal of this research was to perform a systematic study to evaluate the yield of fermentable sugars during dilute sulfuric acid pretreatment that is co-catalyzed with the transition metal Lewis acid salts:AlCl_(3),FeCl_(2),FeCl_(3),and La(OTf)_(3).All Lewis acids apart from FeCl_(2)reduced the presence of xylo-oligomers by a large margin when compared to the non-co-catalyzed control sample *** presence of these xylo-oligomers acts as inhibitors during enzymatic saccaharification *** Lewis acids AlCl_(3),FeCl_(3),and La(OTf)_(3)were also able to marginally increase the overall enzymatic digestibility specifically for corn stover pretreated at 160℃with 10 mM of Lewis *** hard Lewis acid such as AlCl3 increased the formation inhibitory products such as furfural and 5-hydroxymethylfurfural(HMF).There was good correlation between reduction of xylo-oligomers and increased concentration furfural with increase in Lewis acid hardness.

关键词： pretreatment corn stover biomass biofuel enzymatic saccharification Lewis acid transition metal

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Wind-farm and hydrogen-storage co-location system optimization for dynamic frequency response in the UK

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Clean Energy 2023年第1期7卷 157-173页

作者： Fulin Fan Shanay Skellern David Campos-Gaona john Nwobu Department of Electronic and Electrical Engineering University of StrathclydeGlasgowUK 2Offshore Renewable Energy CatapultGlasgowUK

The continuous development of hydrogen-electrolyser and fuel-cell technologies not only reduces their investment and operating costs but also improves their technical performance to meet fast-acting requirements of electrical grid balancing services such as frequency-response *** order to project the feasibility of co-locating a hydrogen-storage system with a wind farm for the dynamic regulation frequency-response provision in Great Britain,this paper develops a modelling framework to coordinate the wind export and frequency responses to the main grid and manage the interaction of the electrolyser,compressor,storage tank and fuel cell within the hydrogen-storage system by respecting the market mechanisms and the balance and conversion of power and hydrogen *** the revenue of frequency-response service provision and a variety of costs induced by the hydrogen-storage system are translated into the net profit of the co-location system,which is maximized by optimizing the capacities of hydrogen-storage-system components,hydrogen-storage levels that guide the hydrogen restoration via operational baselines and the power interchange between a wind-farm and hydrogen-storage system,as well as the capacities tendered for low-and high-frequency dynamic regulation *** developed modelling framework is tested based on a particular 432-MW offshore wind farm in Great Britain combined with the techno-economics of electrolysers and fuel cells projected for 2030 and 2050 *** optimized system configuration and operation are compared between different operating scenarios and discussed alongside the prospect of applying hydrogen-storage systems for frequency-response provision.

关键词： dynamic regulation frequency response hydrogen-storage system techno-economic optimization UK perspective wind farm

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The calibration methods for Multi-Filter Rotating Shadowband Radiometer： a review

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Frontiers of Earth Science 2013年第3期7卷 257-270页

作者： Maosi CHEN john DAVIS Hongzhao TANG Carolyn OWNBY Wei GAO USDA UV-B Monitoring and Research Program Natural Resource Ecology Laboratory Colorado State University Fort Collins CO 80521 USA Department of Ecosystem Science and Sustainability Colorado State University Fort Collins CO 80521 USA

The continuous, over two-decade data record from the Multi-Filter Rotating Shadowband Radiometer （MFRSR） is ideal for climate research which requires timely and accurate information of important atmospheric components such as gases, aerosols, and clouds. Except for parameters derived from MFRSR measurement ratios, which are not impacted by calibration error, most applications require accurate calibration factor（s）, angular correction, and spectral response function（s） from calibration. Although a laboratory lamp （or reference） calibration can provide all the information needed to convert the instrument readings to actual radiation, in situ calibration methods are implemented routinely （daily） to fill the gaps between lamp calibrations. In this paper, the basic structure and the data collection and pretreatment of the MFRSR are described. The laboratory lamp calibration and its limita- tions are summarized. The cloud screening algorithms for MFRSR data are presented. The in situ calibration methods, the standard Langley method and its variants, the ratio-Langley method, the general method, Alexandrov＇s comprehensive method, and Chen＇s multi-channel method, are outlined. The reason that all these methods do not fit for all situations is that they assume some properties, such as aerosol optical depth （AOD）, total optical depth （TOD）, precipitable water vapor （PWV）, effective size of aerosol particles, or angstrom coefficient, are invariant over time. These properties are not universal and some of them rarely happen. In practice, daily calibration factors derived from these methods should be smoothed to restrain elTor.

关键词： Multi-Filter Rotating Shadowband Radiometer (MFRSR) calibration review

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