检索结果-南通市图书馆

Design, manufacture and testing of a prototype obstacle-detection device at blind corners: an automated highway system technology

在线全文

学校读者我要写书评

暂无评论

Transportation Safety and Environment 2021年第1期3卷 10-20页

作者： charles Atombo Emmanuel Gbey Apevienyeku Kwami Holali Department of mechanical Engineering Ho Technical UniversityP.O.Box HP 217HOVolta RegionGhana

Traffic accidents on highways are attributed mostly to the”invisibility”of oncoming traffic and road signs.”Speeding”also causes drivers to reduce the effective radius of the vehicle path in the curve,thus trespassing into the lane of the oncoming *** main aim of this paper was to develop a multisensory obstacle-detection device that is affordable,easy to implement and easy to maintain to reduce the risk of road accidents at blind *** ultrasonic sensor module with a maximum measuring angle of 15◦was used to ensure that a significant portion of the lane was detected at the blind *** sensor covered a minimum effective area of 0.5 m2 of the road for obstacle *** light was employed to signify caution while negotiating the blind *** photoresistors(PRs)were used as sensors because of the limited number of pins on the microcontroller(Arduino Uno).However,the device developed for this project achieved obstacle detection at blind corners at relatively low cost and can be accessed by all road *** real-world applications,the use of piezoelectric accelerometers(vibration sensors)instead of PR sensors would be more desirable in order to detect not only cars but also two-wheelers.

关键词： Arduino blind corner microcontroller obstacle detection road accidents

Large endoscopic mucosal resection for colorectal tumors exceeding 4 cm

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2010年第5期16卷 588-595页

作者： Philippe Ah Soune charles ménard Ezzedine Salah Ariadne Desjeux Jean-charles Grimaud marc Barthet Department of Gastroenterology Hpital NordChemin des Bourrely13915 Marseille cedex 20France

AIm:To evaluate the feasibility and the outcome of endoscopic mucosal resection(EmR)for large colorectal tumors exceeding 4 cm(LCRT)undergoing piecemeal resection. mETHODS:From January 2005 to April 2008,146 digestive tumors larger than 2 cm were removed with the EmR technique in our *** these,34 tumors were larger than 4 cm and piecemeal resection was carried out on 26 colorectal *** mean age of the patients was 71 *** mean follow-up duration was 12 mo. RESULTS:LCRTs were located in the rectum,left colon,transverse colon and right colon in 58%,15%, 4%and 23%of cases,*** were sessile tumors larger than 4 cm with a mean size of 4.9 cm (4-10 cm).According to the Paris classification,34%of the tumors were typeⅠs,58%typeⅡa,4%typeⅡb and 4%typeⅡ*** examination showed tubulous adenoma in 31%,tubulo-villous adenoma in 27%,villous adenoma in 42%,high-grade dysplasia in38%,in situ carcinoma in 19%of the cases and mucosal carcinoma(m2)in 8%of the *** two cases(7.7%)of procedural bleeding that occurred were managed endoscopically and one small perforation was treated with *** follow-up,recurrence of the tumor occurred in three patients(12%),three of whom received endoscopic treatment. CONCLUSION:EmR for tumors larger than 4 cm is a safe and effective procedure that could compete with endoscopic submucosal dissection,despite providing incomplete histological assessment.

关键词： Endoscopic mucosal resection Perforation Colorectal carcinoma Large polyps

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

The magic of markets

中国会计评论 2003年 1卷 219-240页

作者： charles m.C.Lee Johnson Graduate School of management Comell UniversityIthacaNY 14850USA.

The way markets aggregate information and facilitate decentralized planning is almost magical. But paradoxically, the magic continues only because the process is flawed. Therefore, the market is better characterized as being adaptive rather than efficient; and our research should seek to understand, rather than assume, the adaptive process.

关键词：中国会计评论刃刀

Structure of a cereal purple acid phytase provides new insights to phytate degradation in plants

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Plant Communications 2022年第2期3卷 52-61页

作者： Raquel Faba-Rodriguez Yinghong Gu melissa Salmon Giuseppe Dionisio Henrik Brinch-Pedersen charles A.Brearley Andrew m.Hemmings School of Chemistry University of East AngliaNorwich Research ParkNorwich NR47TJUK School of Biological Sciences University of East AngliaNorwich Research ParkNorwich NR47TJUK Department of Agroecology Research Center FlakkebjergAarhus University4200 SlagelseDenmark College of Food Science and Technology Shanghai Ocean UniversityShanghai 201306China

Grain phytate,a mixed metal ion salt of inositol hexakisphosphate,accounts for 60%–80%of stored phosphorus in plants and is a potent antinutrient of non-ruminant animals including *** neofunctionalization of purple acid phytases(PAPhy),some cereals such as wheat and rye have acquired particularly high mature grain phytase *** PAPhy activity supplies phosphate,liberates metal ions necessary for seedling emergence,and obviates antinutrient effects of phytate,its manipulation and control are targeted crop *** we show the X-ray crystal structure of the b2 isoform of wheat PAPhy induced during *** high-resolution crystal structure suggests a model for phytate recognition that,validated by molecular dynamics simulations,implicates elements of two sequence inserts(termed PAPhy motifs)relative to a canonical metallophosphoesterase(mPE)domain in forming phytate-specific substrate specificity *** motifs are well conserved in PAPhys from monocot cereals,enzymes which are characterized by high specificity for *** by mutagenesis,residues His229 in PAPhy motif 4 and Lys410 in the mPE domain,both conserved in PAPhys,are found to strongly influence phytase *** results explain the observed phytase activity of cereal PAPhys and open the way to the rational engineering of phytase activity in planta.

关键词： wheat purple acid phytase X-ray crystallography stereospecificity

CHARACTERIZATIONS OF FUNDAmENTAL SCALING FUNCTIONS AND WAVELETS

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Analysis in Theory and Applications 1993年第3期9卷 37-52页

作者： charles K.Chui Center for Approximation Theory Texas A&m University College Station TX 77843-3368

The objective of Ibis paper is to establish precise characterizations of scaling functions which are orthonormal or fundamental.A criterion for the corresponding wavelets is also given.

关键词： CHARACTERIZATIONS OF FUNDAmENTAL SCALING FUNCTIONS AND WAVELETS mallat

Thrust characteristics of nano-carbon/Al/oxygenated salt nanothermites for micro-energetic applications

在线全文

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2023年第12期30卷 55-69页

作者： Ahmed Fahd Alex Baranovsky charles Dubois Jamal Chaouki Sherif Elbasuney Shady Shokry Chemical Engineering Department Ecole Polytechnique de MontrealMontrealH3C 3A7Canada Energetic materials and Nanotechnology Research Center Technical Research CenterCairo11765Egypt mechanical and mechatronics Engineering Department University of WaterlooOntarioN2L 3G1Canada Head of Nanotechnology Research Center Military Technical CollegeCairo11767Egypt Laser and Optoelectronics Research Center Technical Research CenterCairo11765Egypt

Combustion within small motors is key in the application-specific development of nanothermite-based micro-energetic systems. This study evaluates the performance of nanothermite mixtures in a converging-diverging nozzle and an open tube. mixtures were prepared using nano-aluminum(n-Al),potassium perchlorate(KClO_(4)), and different carbon nanomaterials(CNms) including graphene-oxide(GO), reduced GO, carbon nanotubes(CNTs) and nanofibers(CNFs). The mixtures were packed at different densities and ignited by laser beam. Performance was measured using thrust measurement,high-speed imaging, and computational fluid dynamics modeling, respectively. Thrust, specific impulse(ISP), volumetric impulse(ISV), as well as normalized energy were found to increase notably with CNm content. Two distinctive reaction regimes(fast and slow) were observed in combustion of low and high packing densities(20% and 55%TmD), respectively. Total impulse(IFT) and ISPwere maximized in the 5%GO/Al/KClO_4 mixture, producing 7.95 m N·s and 135.20 s respectively at 20%TmD, an improvement of 57%compared to a GO-free sample(5.05 m N·s and 85.88 s). CFD analysis of the motors over predicts the thrust generated but trends in nozzle layout and packing density agree with those observed experimentally;peak force was maximized by reducing packing density and using an open tube. The numerical force profiles fit better for the nozzle cases than the open tube scenarios due to the rapid nature of combustion. This study reveals the potential of GO in improving oxygenated salt-based nanothermites,and further demonstrates their applicability for micro-propulsion and micro-energetic applications.

关键词： Nanothermites Graphene oxide Reduced graphene oxide Carbon nano material Oxygenated salts Laser ignition Computational fluid dynamics

Impact of enclosure management on soil properties and microbial biomass in a restored semi-arid rangeland, Kenya

在线全文

学校读者我要写书评

暂无评论

Journal of Arid Land 2014年第5期6卷 561-570页

作者： Stephen m mUREITHI Ann VERDOODT charles KK GACHENE Jesse T NJOKA Vivian O WASONGA Stefaan De NEVE Elizabeth mEYERHOFF Eric Van RANST Laboratory of Soil Science Department of Geology and Soil Science Ghent University Department of Land Resources management and Agricultural Technology University of Nairobi Research Unit of Soil Degradation and Conservation Department of Soil Management Ghent University Rehabilitation of Arid Environments Trust

Rangeland degradation is a serious problem throughout sub-Saharan Africa and its restoration is a challenge for the management of arid and semi-arid areas. In Lake Baringo Basin of Kenya, communities and individual farmers are restoring indigenous vegetation inside enclosures in an effort to combat severe land degradation and address their livelihood problems. This study evaluated the impact of enclosure management on soil properties and microbial biomass, being key indicators of soil ecosystem health. Six reseeded communal enclosures using soil embankments as water-harvesting structures and strictly regulated access were selected, varying in age from 13 to 23 years. In six private enclosures, ranging from 3 to 17 years in age, individual farmers emulated the communal enclosure strategy and restored areas for their exclusive use. Significant decreases in bulk density, and increases in the soil organic carbon, total nitrogen and microbial biomass contents and stocks were found in the enclosures as compared with the degraded open rangeland. In the private enclosures, the impact of rehabilitation on the soil quality was variable, and soil quality was in general lower than that obtained under communal management. The significant increase of absolute stocks of carbon, nitrogen and microbial biomass compared to the degraded open rangeland indicates the potential for the restoration of soil quality through range rehabilitation. Over-sowing with indigenous legume fodder species could improve total nitrogen content in the soil and nutritional value of the pastures as well.

关键词： rangeland degradation enclosures microbial biomass rehabilitation reseeding soil quality Kenya

Vertebrate pesticide risk assessment by indigenous communities in New Zealand

在线全文

学校读者我要写书评

暂无评论

Integrative Zoology 2010年第1期5卷 37-43页

作者： Shaun C.OGILVIE James m.ATARIA James WAIWAI James DOHERTY Aroha mILLER James G.ROSS charles T.EASON Ecology Department Lincoln UniversityLincolnCanterburyNew Zealand Landcare Research LincolnCanterburyNew Zealand Lake Waikaremoana Hapu Restoration Trust TuaiNew Zealand Tuhoe Tuawhenua Trust MuruparaNew Zealand

In New Zealand,the vertebrate pesticide sodium fluoroacetate(Compound 1080)is aerially applied in baits for control of the brush-tailed possum Trichosurus vulpecula(Kerr,1792).maori,the indigenous people of New Zealand,have raised concerns about 1080 impacts on culturally-important ***,we outline two steps taken to help maori assess 1080 ***,field research was undertaken to determine if naturally-occurring plants utilized by a maori community for food and medicine would take up 1080 from *** baits were placed at the base of individual plants of two species,pikopiko(Asplenium bulbiferum)and karamuramu(Coprosma robusta).Plants were sampled at various times up to 56 days,and samples were analyzed for 1080 *** 1080 was detected in any of the pikopiko samples,whereas 1080 was detected in karamuramu,at a maximum concentration of 5 ppb after seven days,and 2.5 ppb after 14 *** concentration decreased to 0 at 28 days,indicating that 1080 was not *** results of the present study suggest there is negligible risk of humans being poisoned by consum-ing plants that have taken up 1080 from *** allay community concerns that minute concentrations of 1080 might influence the medicinal properties of plants,it is suggested that a withholding period of 30 days after 1080 control operations could be ***,after further consultation we undertook a review of the scientific literature relating to 1080 impacts on additional non-target species of cultural importance to *** information was presented on an interactive foodweb database that allowed the collection and presentation of a large volume of complex information about 1080 in a holistic and pictorial *** database was presented to many maori communities throughout New Zealand,and feedback was overwhelmingly *** database is likely to play a key role in informing these communities about 1080,and is seen as an important new tool to help these communities

关键词： 1080 indigenous communities maori risk assessment sodium fluoroacetate

Appraising the manifestation of Optimism Bias and Its Impact on Human Perception of Cyber Security: A meta Analysis

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Information Security 2023年第2期14卷 93-110页

作者： Khaled m. Alnifie charles Kim Department of Electrical Engineering and Computer Science Howard University Washington DC USA

Cyber threats and risks are increasing exponentially with time. For preventing and defense against these threats and risks, precise risk perception for effective mitigation is the first step. Risk perception is necessary requirement to mitigate risk as it drives the security strategy at the organizational level and human attitude at individual level. Sometime, individuals understand there is a risk that a negative event or incident can occur, but they do not believe there will be a personal impact if the risk comes to realization but instead, they believe that the negative event will impact others. This belief supports the common belief that individuals tend to think of themselves as invulnerable, i.e., optimistically bias about the situation, thus affecting their attitude for taking preventive measures due to inappropriate risk perception or overconfidence. The main motivation of this meta-analysis is to assess that how the cyber optimistic bias or cyber optimism bias affects individual’s cyber security risk perception and how it changes their decisions. Applying a meta-analysis, this study found that optimistic bias has an overall negative impact on the cyber security due to the inappropriate risk perception and considering themselves invulnerable by biasing that the threat will not occur to them. Due to the cyber optimism bias, the individual will sometimes share passwords by considering it will not be maliciously used, lack in adopting of preventive measures, ignore security incidents, wrong perception of cyber threats and overconfidence on themselves in the context of cyber security.

关键词： Cyber Security meta-Analysis Optimistic Bias Optimism Bias Risk Perception Cognitive Bias