检索结果-南通市图书馆

维普期刊数据库

Predicting global landslide spatiotemporal distribution:Integrating landslide susceptibility zoning techniques and real-time satellite rainfall estimates

在线全文

学校读者我要写书评

暂无评论

International Journal of Sediment Research 2008年第3期23卷 249-257页

作者： robert F. adler Senior Research Scientist Code 613.1 Laboratory for Atmospheres NASA/Goddard Space Flight Center Greenbelt MD 20771 U. S. ADr.

Landslides triggered by rainfall can possibly be foreseen in real time by jointly using rainfall intensity-duration thresholds and information related to land surface susceptibility. However, no system exists at either a national or a global scale to monitor or detect rainfall conditions that may trigger landslides due to the lack of sufficient ground-based observing network in many parts of the world. Recent advances in satellite remote sensing technology and increasing availability of high-resolution geospatial products around the globe have provided an unprecedented opportunity for such a study. In this paper, a framework for developing a preliminary real-time prediction system to identify where rainfall-triggered landslides will occur is proposed by combining two necessary components: surface landslide susceptibility and a real-time space-based rainfall analysis system (http://***). First, a global landslide susceptibility map is derived from a combination of semi-static global surface characteristics (digital elevation topography, slope, soil types, soil texture, land cover classification, etc.) using a GIS weighted linear combination approach. Second, an adjusted empirical relationship between rainfall intensity-duration and landslide occurrence is used to assess landslide hazards at areas with high susceptibility. A major outcome of this work is the availability for the first time of a global assessment of landslide hazards, which is only possible because of the utilization of global satellite remote sensing products. This preliminary system can be updated continuously using the new satellite remote sensing products. This proposed system, if pursued through wide interdisciplinary efforts as recommended herein, bears the promise to grow many local landslide hazard analyses into a global decision-making support system for landslide disaster preparedness and mitigation activities across the world.

关键词： Landslide Natural disasters Satellite remote sensing Real-time precipitation analysis Landslide susceptibility

Long-term effect of intrathecal baclofen treatment on bone health and body composition after spinal cord injury:A case matched report

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

World Journal of Orthopedics 2020年第10期11卷 453-464页

作者： Dora E Ifon Mina P Ghatas John C Davis Refka E Khalil robert A adler Ashraf S Gorgey Spinal Cord Injury and Disorders Center Central Virginia VA Health Care SystemRichmondVA 23249United States Medical Service Central Virginia VA Health Care SystemRichmondVA 23249United States Department of Internal Medicine Division of EndocrinologyDiabetes and MetabolismVirginia Commonwealth UniversityRichmondVA 23298United States Department of Physical Medicine and Rehabilitation Virginia Commonwealth UniversityRichmondVA 23298United States

BACKGROUND Severe spasticity may negatively impact functionality and quality of life after spinal cord injury(SCI).Intrathecal baclofen treatment(IBT)is effectively used to manage severe spasticity and reduce ***,long-term IBT may have a negative effect on bone mineral content(BMC),bone mineral density(BMD)and body composition(such as percentage fat mass and lean body mass).We demonstrated the negative effects of long-term IBT use in a single case compared with two non-IBT *** SUMMARY A 46-year old Caucasian male Veteran(case)with a 21 year history of complete tetraplegia(complete C6 SCI)was implanted with IBT for 20 *** case was matched to two participants with different time since injuries[2(match 1)and 13(match 2)years]without *** BMC and BMD at the epiphysis and metaphysis of the distal femur and proximal tibia were evaluated using dual knee and the dual femur modules of GE Lunar iDXA *** and leg body composition assessments were also conducted for the three *** effect of long-term IBT was demonstrated by changes in BMD,consistent with bone demineralization,at the distal femur and proximal tibia and changes in percentage fat mass and lean mass of *** case showed 113%lower BMD at the distal femur,and 78.1%lower at the proximal tibia compared to match 1,moreover the case showed 45%lower BMD at the distal femur,and no observed changes at the proximal tibia compared to match *** case had 27.1%and 16.5%greater leg%fat mass compared to match 1 and match 2,***,the case had 17.4%and 11.8%lower%leg lean mass compared to match 1 and match 2,*** Long-term IBT may impact bone health and body composition parameters in persons with complete *** may be prudent to encourage regular screening of individuals on long-term IBT considering the prevalence of osteoporosis related fractures,cardiovascular diseases,and metabolic disorders in this population.

关键词： Intrathecal baclofen Spasticity Bone mineral density Epiphysis Metaphysis Spinal cord injury Case report

Predicting the coefficient of friction in a sliding contact by applying machine learning to acoustic emission data

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Friction 2024年第6期12卷 1299-1321页

作者： robert GUTIERREZ Tianshi FANG robert MAINWARING Tom REDDYHOFF Tribology Group Department of Mechanical EngineeringImperial College LondonExhibition RoadLondon SW72AZUK Shell Global Solutions(US)Inc.Shell Technology Center Houston 3333 Highway 6 SouthHoustonTX 77082USA Shell International Petroleum Company Limited Shell CentreYork RoadLondon SE17NAUK

It is increasingly important to monitor sliding interfaces within machines,since this is where both energy is lost,and failures *** emission(AE)techniques offer a way to monitor contacts remotely without requiring transparent or electrically conductive ***,acoustic data from sliding contacts is notoriously complex and difficult to ***,we simultaneously measure coefficient of friction(with a conventional force transducer)and acoustic emission(with a piezoelectric sensor and high acquisition rate digitizer)produced by a steel‒steel rubbing *** data is then used to train machine learning(ML)algorithms(e.g.,Gaussian process regression(GPR)and support vector machine(SVM))to correlated acoustic emission with *** training requires the dense AE data to first be reduced in size and a range of processing techniques are assessed for this(e.g.,down-sampling,averaging,fast Fourier transforms(FFTs),histograms).Next,fresh,unseen AE data is given to the trained model and the resulting friction predictions are compared with the directly measured *** is excellent agreement between the measured and predicted friction when the GPR model is used on AE histogram data,with root mean square(RMS)errors as low as 0.03 and Pearson correlation coefficients reaching ***,predictions remain accurate despite changes in test conditions such as normal load,reciprocating frequency,and stroke *** paves the way for remote,acoustic measurements of friction in inaccessible locations within machinery to increase mechanical efficiency and avoid costly failure/needless maintenance.

关键词： acoustic emission condition monitoring friction machine learning Gaussian process regression support vector machine

Necrotic enteritis and antibiotic-free production of broiler chickens:Challenges in testing and using alternative products

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Animal Nutrition 2024年第1期16卷 288-298页

作者： robert J.Moore School of Science RMIT University

The global trend towards raising broiler chickens without the use of in-feed antibiotics(IFAs) means that there is an ongoing need to develop alternative treatments capable of delivering the benefits that IFAs previously provided. IFAs supported the productivity performance of chickens and played a key role in maintaining their health. Necrotic enteritis(NE) is an important disease of broilers that affects health,productivity, and welfare, and was previously well controlled by IFAs. However, with the reduction in IFA use, NE is resurgent in some countries. Vaccines and various feed additives, including pre-, pro-, and postbiotics, phytobiotics, fatty acids, and phage therapies have been introduced as alternative methods of NE control. While some of these feed additives have specific activity against the NE pathogen, Clostridium perfringens, most have the more general goal of reinforcing gut health. Extensive reviews of the effects of many of these feed additives on gut health have been published recently. Hence, rather than cover previously well reviewed areas of research this review focuses on the challenges and pitfalls in undertaking experimental assessment of alternative NE treatments and translating laboratory research to real world commercial production settings. The review is based on the author's particular experience,reading, thoughts, and analysis of the available information and inevitably presents a particular understanding that is likely to be at odds with others thinking on these issues. It is put forward to stimulate thinking and discussion on the issues covered.

关键词： Necrotic enteritis Clostridium perfringens Vaccines Feed additive Farm management

A Note on Reviving the Goddard Satellite-Based Surface Turbulent Fluxes (GSSTF) Dataset

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Advances in Atmospheric Sciences 2009年第6期26卷 1071-1080页

作者： Chung-Lin SHIE Long S. CHIU robert adler Eric NELKIN I-I LIN Pingping XIE Feng-Chin WANG R. CHOKNGAMWONG William OLSON D. Allen CHU UMBC/GEST Baltimore Maryland USA Code 613.1 NASA/GSFC Greenbelt Maryland USA GMU/CEOSR Fairfax Virginia USA CUHK/ISEIS Shatin NT Hong Kong UMCP/ESSIC College Park Maryland USA SSAI Lanham Maryland USA NTU Taipei Taiwan NOAA/CPC Camp Springs Maryland USA CWB Taipei Chinese Taiwan UMBC/JCET Baltimore Maryland USA Code 613.2 NASA/GSFC Greenbelt Maryland USA

Accurate sea surface flux measurements are crucial for understanding the global water and energy cycles. The oceanic evaporation, which is a major component of the global oceanic fresh water flux, is useful for predicting oceanic circulation and transport. The global Goddard Satellite-based Surface Turbulent Fluxes Version-2 （GSSTF2; July 1987–December 2000） dateset that was o？cially released in 2001 has been widely used by scientific community for global energy and water cycle research, and regional and short period data analyses. We have recently been funded by NASA to resume processing the GSSTF dataset with an objective of continually producing a uniform dataset of sea surface turbulent fluxes, derived from remote sensing data. The dataset is to be reprocessed and brought up-to-date （GSSTF2b） using improved input datasets such as a recently upgraded NCEP/DOE sea surface temperature reanalysis, and an upgraded surface wind and microwave brightness temperature V6 dataset （Version 6） from the Special Sensor Microwave Imager （SSM/I） produced by Remote Sensing Systems （RSS）. A second new product （GSSTF3） is further proposed with a finer temporal （12-h） and spatial （0.25° × 0.25°） resolution. GSSTF2b （July 1987–December 2008） and GSSTF3 （July 1999–December 2009） will be released for the research community to use by late 2009 and early 2011, respectively.

关键词： surface turbulent fluxes global oceanic satellite-based

维普期刊数据库

A detailed rock density model of the Hong Kong territories

在线全文

学校读者我要写书评

暂无评论

Geodesy and Geodynamics 2024年第1期15卷 75-81页

作者： Albertini Nsiah Ababio robert Tenzer Department of Land Surveying and Geo-Informatics Hong Kong Polytechnic UniversityHong KongChina

We used the geological map and published rock density measurements to compile the digital rock density model for the Hong Kong *** then estimated the average density for the whole *** to our result,the rock density values in Hong Kong vary from 2101 to 2681 kg·m^(-3).These density values are typically smaller than the average density of 2670 kg·m^(-3),often adopted to represent the average density of the upper continental crust in physical geodesy and gravimetric geophysics *** finding reflects that the geological configuration in Hong Kong is mainly formed by light volcanic formations and lava flows with overlying sedimentary deposits at many locations,while the percentage of heavier metamorphic rocks is very low(less than 1%).This product will improve the accuracy of a detailed geoid model and orthometric heights.

关键词： Density model Rock types Gravimetric modeling Hong Kong

维普期刊数据库

Hydrogen Peroxide Electrosynthesis in a Strong Acidic Environment Using Cationic Surfactants

在线全文

学校读者我要写书评

暂无评论

Precision Chemistry 2024年第4期2卷 129-137页

作者： Zachary adler Xiao Zhang Guangxia Feng Yaping Shi Peng Zhu Yang Xia Xiaonan Shan Haotian Wang Rice University Department of Chemical and Biomolecular EngineeringHoustonTexas 77005United States University of Houston Department of Electrical and Computer EngineeringHoustonTexas 77004United States

The two-electron oxygen reduction reaction(2e^(−)-ORR)can be exploited for green production of hydrogen peroxide(H_(2)O_(2)),but it still suffers from low selectivity in an acidic electrolyte when using non-noble metal ***,inspired by biology,we demonstrate a strategy that exploits the micellization of surfactant molecules to promote the H_(2)O_(2)selectivity of a low-cost carbon black catalyst in strong acid *** surfactants near the electrode surface increase the oxygen solubility and transportation,and they provide a shielding effect that displaces protons from the electric double layer(EDL).Compared with the case of a pure acidic electrolyte,we find that,when a small number of surfactant molecules were added to the acid,the H_(2)O_(2)Faradaic efficiency(FE)was improved from 12%to 95%H_(2)O_(2)under 200 mA cm^(−2),suggesting an 8-fold *** in situ surface enhanced Raman spectroscopy(SERS)and optical microscopy(OM)studies suggest that,while the added surfactant reduces the electrode’s hydrophobicity,its micelle formation could promote the O_(2) gas transport and its hydrophobic tail could displace local protons under applied negative potentials during catalysis,which are responsible for the improved H_(2)O_(2)selectivity in strong acids.

关键词： electrocatalysis hydrogen peroxide electrosynthesis oxygen reduction reaction interfacial engineering surfactant CTAB

Optimization of product characteristics of porous carbon agglomerates using a design of experiments in fluidized bed agglomeration

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Particuology 2024年第6期89卷 258-269页

作者： Martin Oelofse robert Rack Marcelle Hilden Peter Langguth Department of Pharmaceutical Technology and Biopharmaceutics Johannes Gutenberg UniversityMainzGermany Carbon Advanced Solutions GmbH HeuchelheimGermany

Spraying parameters during particle agglomeration processes can affect the agglomeration kinetics and particle *** study was conducted to better understand the influence of the spraying parameters in a fluidized bed wet agglomeration process,and the influence on the stability characteristics of carbon tablets.A formulation based on fine carbon and peroxide powder,as well as carboxymethyl cellulose as a binder,was used to produce agglomerates in a first production *** in a second production step carbon tablets with a high porosity were molded for the customer goods *** optimization of the compressive strength of these carbon tablets was the goal of the *** agglomerates were produced with a laboratory scale granulator called“ProCell”and were compressed with a five-cavity mechanical *** screening of the agglomeration process parameters and their influence on the agglomerates quality,as well as the performance characteristics of the carbon tablets,were investigated using a multilevel factorial *** experimental runs were done by varying atomized air pressure and feed rate of the *** was determined by the design *** findings of the statistical trials showed that low atomized air pressure and a low feed rate lead to a higher tablet compressive strength.

关键词： Wet agglomeration Fluidized bed Design of experiments Carbon agglomerates and tablets

The influence of various grease compositions and silver nanoparticle additives on electrically induced rolling-element bearing damage

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Friction 2024年第4期12卷 796-811页

作者： Samuel BOND robert L.JACKSON German MILLS Department of Chemistry and Biochemistry Auburn UniversityAuburn 36849-5412USA Department of Mechanical Engineering Auburn UniversityAuburn 36849-5412USA

Leakage currents accelerate surface degradation of metal contacts via small scale arcing across lubricating films,but recent observations suggest that metallic nanoparticle additives in lubricants may be useful to improve contact *** findings prompted a study that examined electrically induced surface pitting of steel contacts in the presence of several lubricating greases including some containing nanometer-sized colloidal silver(Ag)*** rolling sphere-on-disk experiments were conducted under electro-tribological loads employing polyurea greases derived from mineral and synthetic base oils with and without *** forces and electrical resistance were monitored continuously during the tests;surface changes were characterized by means of optical spectroscopy,stylus profilometry,and scanning electron microscopy(SEM)including compositional analysis using energy dispersive spectroscopy(EDS).The observations demonstrate that surface pitting induced by arcing occurs mainly at the points were the rolling motion changes direction and that eroded metal is deposited along the wear ***-sized pits are formed which contain carbon and oxygen indicating that arcing causes decomposition of the hydrocarbon *** findings indicate a significant inhibition of pitting is induced by the Ag nanoparticles;some greases containing other additives exhibit a similar,although less pronounced,effect.

关键词： electric motor bearings wheel bearings electric vehicles arcing electrically induced bearing damage pitting leakage current stray current