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Anomalous wind circulation over Taipei, Taiwan during the northern winter seasons of 2004 and 2005- A case study
Get PDFThis research reports, for the first time, an anomalous wind circulation over Taipei (Latitude 25.030N, Longitude 121.510E), Taiwan during the northern hemisphere winter season (December, January, and February) of years 2004 and 2005. The anomalous wind circulation of meridional winds, which showed southward directions during the winter seasons of 2004 and 2005 instead of northward winds, is noticed from one kilometer altitude range (lower troposphere) and that trend continued till around 20 km altitude range (lower stratosphere). To ascertain whether such a disturbed nature of wind pattern existed over nearby locations to Taipei, we have analyzed radiosonde-measured meridional and zonal winds over four nearby stations station to Taipei including, Roig, Xiamen, Minami and Fuzhou. Surprisingly, no anomalous wind behavior is seen except over Taipei during the northern winter seasons of 2004 and 2005. On the other hand, the European Centre for Medium-Range Weather Forecasts (ECMWF) model-predicted winds do not show any anomalous wind patterns over Taipei and other nearby stations, possibly due to the large averaging of internal variabilities of reanalysis databases. The plausible physical mechanisms of these disturbed meridional wind patterns are not understood at this juncture, but it is believed that local winds and atmospheric pollutants might have created an amicable environment as to provide such a disturbed meridional wind pattern over Taipei, Taiwan in the winter season of 2004 and 2005
Test and evaluation of a simple parameterization to enhance air-sea coupling in a global coupled model
Get PDFA simple temperature-dependent wind stress scheme is implemented in National Center for Atmospheric Research (NCAR) Community Earth System Model (CESM), aiming to enhance positive wind stress and sea surface temperature (SST) correlation in SST-frontal regions. A series of three-year coupled experiments are conducted to determine a proper coupling coefficient for the scheme based on the agreement of surface wind stress and SST at oceanic mesoscale between model simulations and observations. Afterwards, 80-year simulations with/without the scheme are conducted to explore its effects on simulated ocean states and variability. The results show that the new scheme indeed improves the positive correlation between SST and wind stress magnitude near the large oceanic fronts. With more realistic surface heat flux and wind stress, the global SST biases are reduced. The global ocean circulation represented by barotropic stream function exhibits a weakened gyre circulation close to the western boundary separation, in agreement with previous studies. The simulation of equatorial Pacific current system is improved as well. The overestimated El Niño Southern Oscillation (ENSO) magnitude in original CESM is reduced by ~30% after using the new scheme with an improved period
The variation changes of the precipitation – runoff relationship
Get PDFThe variation of the rainfall-runoff relationship t will lead to the disappearance of the consistency assumption of engineering hydrology, which will influence the planning, design, operation management and development and utilization of water resources. Therefore, the variation diagnosis of the rainfall -runoff relationship has become one of the hot topics and key issues in this area. In this study, the variation points of the precipitation-runoff relationship are defined, the difference between the variation point and the mutation point is distinguished, and the method of variation classification is proposed based on the the dimensionless mean and variation coefficients. Then, a comprehensive diagnosis system of the rainfall-runoff relationship variation is constructed on the basis of systematically summarying and analyzing of the diagnosis method of rainfall - runoff relationship variation at home and abroad. Taking the Weihe River Basin as a case study, the comprehensive diagnosis system is verified by applying it to test the change point the annual runoff time series at the Huaxian hydrological station. And the results show that the comprehensive diagnosis method proposed in this paper is scientific and reasonable
The Nature of Gamma-ray Bursts in the Framework of the Byuon Theory
Get PDFTwo models of gamma-ray bursts using the theory of byuons (TB) are considered. This theory describes a “life” of special unobservable discrete objects from which the surrounding space and the world of ultimate particles are formed. Basic axioms and some conclusions of this theory are discussed. It is shown that basic problems with nature of gamma-rays bursts can be solved in the framework of this theory not only for bursts connected with supernova explosions but also for those without explosions
Multimodal biometric authentication
Get PDFIn the present era of information technology, there is a need to implement authentication and authorization techniques for security of resources. There are number of ways to prove authentication and authorization. But the biometric authentication beats all other techniques. Biometric techniques prove the authenticity or authorization of a human being based on his/her physiological or behavioural traits. Biometrics is a technique by which an individual's identity can be authenticated by applying the physical or behavioural trait. Physical traits like fingerprints, palm, iris etc. are based on the physical characteristics which are generally inherent and unique. Behavioural traits like voice, signature or keystroke dynamics etc. on the other hand, are quantifiable characteristics.They also protect access of resources from unauthorized users. Multimodal biometrics refers to the use of a combination of two or more biometric modalities in a verification / identification system. Identification based on multiple biometrics represents an emerging trend. The most compelling reason to combine different modalities is to improve the recognition rate. This can be done when biometric features of different biometrics are statistically independent. A multimodal biometric identification system aims to fuse two or more physical or behavioural traits. Multimodal biometric system is used in order to improve the accuracy. Multimodal biometric identification system based on iris, palm and fingerprint trait based on fusion logic is proposed. Typically in a multimodal biometric system, each biometric trait processes its information independently. The processed information is combined using curve let transform
Study on the influence of the springback on the hole expansion ratio characterization
Get PDFMaterial formability has become one of the main problems, together with the springback, when stamping high added-value components for the automotive industry. The pursuit of weight reduction has led to higher strength alloys which show a lower formability. Among the different formability criteria (e.g. necking, edge strain, fracture and radius cracks) the edge strain is starting to be a critical aspect on the process planning stage. In order to characterise this criteria, the hole expansion ratio (HER) is conducted under the ISO 16630 standard. In the last years, multiple authors have analysed the HER of different alloys and its dependency on different process variables i.e. cutting method, test speed, material strength. However, the influence of the springback phenomenon on the test result has not been previously analysed. In this work, the influence of the springback on the HER values has been analysed for a mild steel DX54D and a third generation steel Fortiform1050 with a novel measuring technique. From the obtained results, it can be stated that the springback has a critical influence on the characterised HER value, mainly for the third generation steel, leading to differences of about 40% on the HER limits
Preparation and Study of Waterborne Asphalt Pavement Maintenance Agent
Get PDFThe precursor Ni0.76Co0.1Mn0.1 (OH) 2 was prepared by coprecipitation method. The precursor was mixed withMg (OH) 2 / Zn (NO3) 2 / TiO2 and LiOH.H2O, Li2CO3 to synthesize doped lithium Ion layer positive electrodematerial Li [Ni0.8-xCo0.1Mn0.1Mx] O2 (x = 0.04). The effects of synthesis conditions on the chemical propertiesof the composites were discussed. The synthesized samples were prepared by scanning electron microscopy (SEM),thermogravimetry - diff erential thermal analysis (TG / DTA), X - ray diff raction (XRD) and constant current charge- Testing and characterization. The results show that the crystallinity of Li [Ni0.8-xCo0.1Mn0.1Mx] O2 (x = 0.04)prepared at 900 ℃ for 20 h is good, and it has good layered structure. The properties of the doped elements The resultsshow that the electrochemical performance of the samples with Mg and Zn is good, and the fi rst discharge capacity is0.1.5mA.h / g and 144.2 mA.h / g (2.8 ~ 4.6 V vs Li + / Li ), The fi rst charge and discharge effi ciency was 51.8% and58.1% respectively, and the capacity retention rates after 8 and 10 cycles were 92.4% and 78.5% respectively. The fi rstdischarge capacity of the Ti doped sample was 51.3 mA.h / G, poor electrochemical performance
Investigation of the mechanical and physical properties of PLA produced by injection molding for matrix material of polymer composites
Get PDFPolymer materials are increasingly being used due to their superior properties such as light weight, low cost and corrosion resistance. The difficult destruction of highly advantageous polymers in the environment leads to environmental problems and has some disadvantages as they are obtained from exhausted sources such as oil. These problems brought new quests and biopolymers derived from renewable sources came to the forefront. In this study, mechanical and physical test results applied to PLA, which is biopolymer and their use as matrix are investigated. Mechanical tests show that PLA, which has a tensile strength of 46.88 MPa, an impact strength of 9.27 kJ/m2 and a hardness of 79.6 Shore D, can be used as a substitute for polymers derived from petroleum-based sources
Application of MATLAB in Chemical Engineering Experiment Data Processing
Get PDFIn the context of the continuous strengthening of China's comprehensive national strength, a large number of technical personnel have been trained, and various new technologies have also been developed rapidly. In the past, people engaged in chemical engineering not only need to do chemical experiments with high difficulty and danger, but also deal with complex experimental data, which not only aggravated the burden of researchers, but also wasted time and resources.So the study of Chemical Technology in China need to continue to reform and innovation, MATLAB is an innovative and efficient software, can handle a variety of complex data, thereby greatly reducing the workload of the researchers, now in various experiments of chemical engineering has been widely used.This paper will analyze and study the important role of MATLAB in the data processing part of chemical experiment
Effect of repair methods on mechanical behaviors of repair area in composite laminate fuselage skin with different damage size
Get PDFComposite laminates are widely used in the large civil aircrafts because of their excellent mechanical properties. The maintenance and repair of composite laminates become essential. In this paper, a new adhesive-rivet hybrid repair of composite laminate fuselage skin is presented. For the circular hole damage with the diameter of 90mm and 50mm, the finite element simulation models of adhesive repair and adhesive-rivet hybrid repair were built respectively. Uniform pressure load was applied on these finite element models. The mechanical properties of laminate motherboard, patch and adhesive film for these four models were analyzed. The effects of adhesive repair, adhesive-rivet hybrid repair on mechanical behaviors of repair areas of composite laminate fuselage skins with different damage size were studied. By analyzing the mechanical behaviors of these two repair methods, a suitable repair method can be obtained