摘要：With the application of supercavitation effect, a novel device named rotational supercavitating evaporator(RSCE) was recently designed for desalination. In order to improve the blade shape of rotational cavitator in RSCE for performance optimization and then design three-dimensional blades, numerical simulations are conducted on the supercavitating flows(with cavitation number ranging from 0.055 to 0.315) around two-dimensional planar symmetric wedge-shaped cavitators with different wedge angles varied from 10 to 180 degrees. Proper numerical method for simulating supercavitating flows around planar symmetric cavitator is established, and assessment of k-ε-v2 -f turbulence model in simulating cavitating flows is conducted. It shows that the size of computational domain would affect the simulation result. Empirical formulae for supercavity dimensions about cavitation number at different wedge angles are obtained, which are of significant importance in the subsequent design of three-dimensional blade. The characteristics of resistance at different wedge angles are discussed, which, together with the characteristics of supercavity dimensions, play important roles in the optimal design of RSCE.

摘要：This study examined the relationship between residents＇ level of participation in house design and level of residential satisfaction in Akure, Nigeria. The study was based on the idea that the goal of housing projects is to provide satisfactory environments for users. A cross-sectional survey was conducted on 304 household heads in transitional and peripheral zones of the city. Data were obtained through a structured questionnaire and focus group discussions and observations. The obtained data were subsequently subjected to single-factor descriptive analysis, mean satisfaction scoring, and categorical regression analysis. Results showed a positive significant relationship between the level of resident participation in house design and the level of residential satisfaction. The significant participatory predictors of satisfaction were number of bedrooms, general house design, development of the brief for the design, arrangement of interior spaces, and selection of finishing materials. Space size and building materials were not significant predictors in this context. The obtained p-value of 0.000 indicated that the regression model was significant. This study recommends a high level of resident participation in house design to achieve a high level of residential housing satisfaction in Nigeria.

摘要：Purpose-In order to improve the accuracy of project cost prediction,considering the limitations of existing models,the construction cost prediction model based on SVM(Standard Support Vector Machine)and LSSVM(Least Squares Support Vector Machine)is put ***/methodology/approach-In the competitive growth and industries 4.0,the prediction in the cost plays a key ***-At the same time,the original data is dimensionality *** processed data are imported into the SVM and LSSVM models for training and prediction respectively,and the prediction results are compared and analyzed and a more reasonable prediction model is ***/value-The prediction result is further optimized by parameter *** relative error of the prediction model is within 7%,and the prediction accuracy is high and the result is stable.

摘要：The annual turnout of faculty graduates in Nigeria is not only increasing numerically but it is ironically, unemployed and other times unemployable. This assertion is supported by researches in the social sciences and reasons adduced to the trend range from lack of qualitative and unavailability of teaching and research facilities, as well as insufficient capable human resources among others. This paper x-rayed the case of Industrial Design graduates and their post training outcome, to understand whether or not graduates of Industrial Design are gainfully employed, unemployed, or unemployable; and why？ Research design used was survey, while the instrument administered on the sample size was structured questionnaire. Two hundred and thirty-three （233） students of Industrial Design constituted the sample size. The research questions were analyzed with the aid of Table of frequency distribution, while a non-parametric test by way of Friedman＇s two-way ANOVA was used to analyze the hypotheses. The outcome of the study revealed that, though the programme of Industrial Design is evolving as craft-based, it is viable. Graduates of the programme are not unemployable in the Nigerian labour market. Finally, the paper proffers solutions and recommendations in form of ideas and deductions to enhance the aim of the study.

摘要：In this paper, we propose two new explicit Almost Runge-Kutta (ARK) methods, ARK3 (a three stage third order method, i.e., s = p = 3) and ARK34 (a four-stage third-order method, i.e., s = 4, p = 3), for the numerical solution of initial value problems (IVPs). The methods are derived through the application of order and stability conditions normally associated with Runge-Kutta methods;the derived methods are further tested for consistency and stability, a necessary requirement for convergence of any numerical scheme;they are shown to satisfy the criteria for both consistency and stability;hence their convergence is guaranteed. Numerical experiments carried out further justified the efficiency of the methods.

摘要：The increasing demand for reducing vehicle weight in the automotive and aerospace industries has raised the need to develop improved structural aluminum-based alloys. Thus, horizontal solidification experiment with the Al-7%Si-0.3%Mg（mass fraction） alloy was carried out. A water-cooled horizontal directional solidification device was developed and used. Microstructural characterization was carried out using traditional techniques of metallography, optical microscopy and SEM microscopy. The Thermo-Calc software was used to generate the solidification path of the investigated alloy with addition of 0.17% Fe（mass fraction）. The effects of the thermal parameters such as the growth rate（VL）, cooling rate（TC） and solidification local time（tSL） on the formation of the macrostructure and on the dendritic microstructure evolution were evaluated. A columnar to equiaxed transition（CET） was found for VL and TC values from 0.82 to 0.98 mm/s and from 1.71 to 2.55 ℃/s, respectively. The microstructure was characterized by the measurement of the primary and secondary dendrite arm spacings（λ1 and λ2, respectively）. Experimental laws of λ1 =f（VL, TC） and λ2 =f（tSL） were proposed. It is observed that the interdendritic region is composed of the following eutectic mixture： a（Al）＋Si＋p-Al8 Mg3 Fe Si6＋q-Mg2 Si.

摘要：When designing vehicle suspension systems, compromises are usually made when setting the range of values for spring stiffness and damping constant. Suspension parameters are set depending on the operational requirements of the market. Passenger car for example, would require high quality damping while off road vehicle requires high spring stiffness setting. A quarter vehicle suspension model has been used to study the suspension transmissibility in handling and ride at various frequency ratios. The results obtained show that as the frequency ratio increases, transmissibility for handling reduces with increasing suspension stiffness and increases as the damping constant is increased. On the other hand, transmissibility for ride deteriorate as the spring constant is increased but approaches the ideal as the damping constant is increased. The dynamic magnification of the sprung masses reduces while that of the unsprung masses improves as the frequency ratio is increased.

摘要：An enrolment projection model based on the Markov Chain is developed for Apostolic Faith Secondary School, Akwa Ibom State, Nigeria. Six years of data (between 2008/2009-2013/2014 academic sessions) of student enrolment at the school were studied. The study reveals that the enrolments through various grades are not stable and orderly. The model is helpful for the school’s future planning in matters regarding secondary students’ enrolment.

摘要：This paper presents a proposal for an experimental salt cavern in offshore ultra-deep water for CO2 abatement,including the instrumentation plan and well conceptual design evaluated for carbon capture and storage(CCS)*** studies are based on applied computational mechanics associated with field experimentation that has contributed to the technical feasibility of the underground potash mine at the State of Sergipe in *** knowhow allowed the stability analysis of several salt caverns for brine production at the State of Alagoas in Brazil and to the drilling through stratified thick layers of salt of the pre-salt reservoirs in Santos ***,this knowledge has been applied in the design of onshore and offshore salt caverns opened by dissolution for storage of natural gas and *** geomechanical study,through the application of computational mechanics,of offshore giant salt caverns of 450 m high by 150 m in diameter,shows that one cavern can store about 4 billion Sm3 or 7.2 million tons of *** the construction of the giant cavern,which will be the first gas storage offshore in the world,it has been decided to develop an experimental one,with smaller size,to obtained field *** experimental cavern will allow the calibration of parameters to be used in the structural integrity analysis of the cavern and well for storage of natural gas which is rich in CO2 under high pressure.

摘要：The city of New Owerri Nigeria is situated on a flat terrain and rainfall pattern is tropical high. The area is the seat of Government of Imo state and is crisscrossed by network of dual carriage roads adjoining exclusive housing complexes. The road drainage system comprises open concrete drains on both sides of the cambered asphalt pavement. Much of the area is often flooded after a torrential rainfall and the flood water remains in the drains as long as evaporation permits. A study shows that the scenario is due to a number of factors, amongst which siltation and vegetal growth in the drains, poor drainage outlets are, very gentle terrain and poor maintenance culture. The standing pools of water in the drains sustain massive breeding of mosquitoes which constitute health hazard. Replacement of open concrete drains with properly designed trenches backfilled with permeable earth materials, sand, and overlay of grasses does not only reduce standing time of flood water but completely eliminates stagnant water. The method makes use of enlarged surface area of infiltration provided by the trenchless drain and millions of infiltration channels provided by the grass rootlets.