Objectives:The study examined socio-economic status and gender as determinant of dietary practices of senior secondary school students in Edo South Senatorial district for healthy living and sustainability.Methodology...Objectives:The study examined socio-economic status and gender as determinant of dietary practices of senior secondary school students in Edo South Senatorial district for healthy living and sustainability.Methodology:Quasi experimental research design was employed in the study.Three research questions were raised and formulated into hypotheses,tested at 0.05 level of significance.A multistage random sampling technique was used to sample 245 students from two public schools in Oredo local government areas within Edo south senatorial district.Two(2)instruments(questionnaire and achievement test)validated and reliability of 0.64 and 0.84 reliability co-efficient were obtained.The demographic data/SES,dietary practices(DDPSESQ)was used to obtain information on their dietary practices and socio-economic status,while the pictorial nutrition achievement test(PNAT)consisted of the pre-and post-test.The treatment package comprised planned lessons of 40 minutes each for six(6)weeks.The data collected were analyzed using inferential statistics;hypotheses 1 and 2 were tested using the independent t-test while hypothesis 3 was tested using One-Way ANOVA statistics.Findings:The study revealed that there is no significant difference in dietary practices of students of high,medium and low socio-economic status as a result of exposure to pictorial nutrition education.There was no significant difference in dietary practices by gender.The study concluded that socio-economic status does not determine dietary practices of secondary school students for responsible living.展开更多
To investigate the relationship between macro-plastic behavior and meso-deformation mechanism of Mg alloy AZ31, the mathematical models for various deformation mechanisms of slip, twinning and detwinning are establish...To investigate the relationship between macro-plastic behavior and meso-deformation mechanism of Mg alloy AZ31, the mathematical models for various deformation mechanisms of slip, twinning and detwinning are established, respectively. Furthermore, in order to capture the Bauschinger effect under cyclic loading, the back stress is introduced into the three independent deformation mechanisms, respectively. Finally, using the above-mentioned model, a new cyclic plastic constitutive model based on the constitutive theory of crystal deformation for magnesium alloy is established. On this basis, the numerical simulation for AZ31 under cyclic loading with the axial strain amplitude of 1.2% is carried out in accordance with the aforementioned crystal plas- ticity theory associated with the representative volume element model. The comparison between the stress-strain curves obtained from the simulation and the experiments shows that the macro- scopic mechanical responses predicted using the proposed model are in good agreement with the experimental results. In particular, the unique characteristics of cyclic macro-plastic behavior observed in the experiments can be satisfactorily captured by the presented crystal plasticity model. At the mesoscale, these features are caused by the alternate occurrence of twinning and detwinning mechanisms. The further analysis of meso-plastic behavior shows that there are het- erogeneous distributions of twinning, stress-strain and stress triaxiality in polycrystal under cyclic loading.展开更多
The cultivation of desirable aquatic organisms is becoming increasingly important as one of the fastest-growing agro-industrial activities in the world. Nigeria, over the years, practised traditional methods of aquacu...The cultivation of desirable aquatic organisms is becoming increasingly important as one of the fastest-growing agro-industrial activities in the world. Nigeria, over the years, practised traditional methods of aquaculture in tidal pools and floodplains of inland waters. Recently, the coastal region has been the focus of aquaculture development with introduction of cage culture system. Nigeria is one of the top aquaculture producers in Africa with numerous opportunities for large-scale production, and 80% of production is from small-scale farmers who involve in brackish and freshwater cultivation, except mariculture which has several setbacks. Nigeria is yet to show feasible interest in non-fed aquaculture (macroalgae) which is among the world' s most efficient mass producer of proteins and other products. Constraints to production in the industry have been identified, while the prospects can be achieved by expanding aquaculture zones, enhancing management practices of production systems and improving product quality with the resultant creation of jobs, regular income and investment, etc.. This paper explores the status of aquaculture in Nigeria, and the components and the systems of commercial aquaculture were elucidated.展开更多
Diesel particulate matter(DPF) is usually employed to meet the stringent regulations on particulate matter(PM) emissions for diesel engine. To resolve the DPF regeneration problem, comprehensive information about the ...Diesel particulate matter(DPF) is usually employed to meet the stringent regulations on particulate matter(PM) emissions for diesel engine. To resolve the DPF regeneration problem, comprehensive information about the factors influencing PM oxidation behaviors must be understood. Large amounts of factors related to PM oxidation activity have been investigated, however, some relations are still ambiguous. This paper reviews the factors related to PM oxidation activity that the factors are divided into the engine-correlated and engine-uncorrelated factors. The methods with both advantages and disadvantages to test the oxidation behaviors are introduced. The microstructure and ingredient being fundamental factors affecting PM oxidation behaviors are as the principle line to correlate PM oxidation behaviors and engine-correlated factors. The relations of engine-correlated factors with oxidation behaviors are obtained though advanced technologies that are mutual complementation. The engine-uncorrelated factors are also reviewed that these factors are vital to oxidation activity changes. Multiple-factor analysis rather than single-factor analysis should be developed to make the oxidation behaviors of diesel PM more clear.展开更多
文摘Objectives:The study examined socio-economic status and gender as determinant of dietary practices of senior secondary school students in Edo South Senatorial district for healthy living and sustainability.Methodology:Quasi experimental research design was employed in the study.Three research questions were raised and formulated into hypotheses,tested at 0.05 level of significance.A multistage random sampling technique was used to sample 245 students from two public schools in Oredo local government areas within Edo south senatorial district.Two(2)instruments(questionnaire and achievement test)validated and reliability of 0.64 and 0.84 reliability co-efficient were obtained.The demographic data/SES,dietary practices(DDPSESQ)was used to obtain information on their dietary practices and socio-economic status,while the pictorial nutrition achievement test(PNAT)consisted of the pre-and post-test.The treatment package comprised planned lessons of 40 minutes each for six(6)weeks.The data collected were analyzed using inferential statistics;hypotheses 1 and 2 were tested using the independent t-test while hypothesis 3 was tested using One-Way ANOVA statistics.Findings:The study revealed that there is no significant difference in dietary practices of students of high,medium and low socio-economic status as a result of exposure to pictorial nutrition education.There was no significant difference in dietary practices by gender.The study concluded that socio-economic status does not determine dietary practices of secondary school students for responsible living.
基金Project (11462002) supported by the National Natural Science Foundation of China Project (2016GXNSFAA380218) supported by Guangxi Natural Science Foundation, China+1 种基金 Project (2014ZDK002) supported by the Open Project of Guangxi Key Laboratory of Disaster Prevention and Structural Safety at Guangxi University, China and Project (Z01) supported by the Science Foundation for Doctorate Research of Guangxi University of Science and Technology, China.
文摘To investigate the relationship between macro-plastic behavior and meso-deformation mechanism of Mg alloy AZ31, the mathematical models for various deformation mechanisms of slip, twinning and detwinning are established, respectively. Furthermore, in order to capture the Bauschinger effect under cyclic loading, the back stress is introduced into the three independent deformation mechanisms, respectively. Finally, using the above-mentioned model, a new cyclic plastic constitutive model based on the constitutive theory of crystal deformation for magnesium alloy is established. On this basis, the numerical simulation for AZ31 under cyclic loading with the axial strain amplitude of 1.2% is carried out in accordance with the aforementioned crystal plas- ticity theory associated with the representative volume element model. The comparison between the stress-strain curves obtained from the simulation and the experiments shows that the macro- scopic mechanical responses predicted using the proposed model are in good agreement with the experimental results. In particular, the unique characteristics of cyclic macro-plastic behavior observed in the experiments can be satisfactorily captured by the presented crystal plasticity model. At the mesoscale, these features are caused by the alternate occurrence of twinning and detwinning mechanisms. The further analysis of meso-plastic behavior shows that there are het- erogeneous distributions of twinning, stress-strain and stress triaxiality in polycrystal under cyclic loading.
文摘The cultivation of desirable aquatic organisms is becoming increasingly important as one of the fastest-growing agro-industrial activities in the world. Nigeria, over the years, practised traditional methods of aquaculture in tidal pools and floodplains of inland waters. Recently, the coastal region has been the focus of aquaculture development with introduction of cage culture system. Nigeria is one of the top aquaculture producers in Africa with numerous opportunities for large-scale production, and 80% of production is from small-scale farmers who involve in brackish and freshwater cultivation, except mariculture which has several setbacks. Nigeria is yet to show feasible interest in non-fed aquaculture (macroalgae) which is among the world' s most efficient mass producer of proteins and other products. Constraints to production in the industry have been identified, while the prospects can be achieved by expanding aquaculture zones, enhancing management practices of production systems and improving product quality with the resultant creation of jobs, regular income and investment, etc.. This paper explores the status of aquaculture in Nigeria, and the components and the systems of commercial aquaculture were elucidated.
基金support by the Science and Technology Planning Project of Hebei Province,China(Grant No.15273703D)
文摘Diesel particulate matter(DPF) is usually employed to meet the stringent regulations on particulate matter(PM) emissions for diesel engine. To resolve the DPF regeneration problem, comprehensive information about the factors influencing PM oxidation behaviors must be understood. Large amounts of factors related to PM oxidation activity have been investigated, however, some relations are still ambiguous. This paper reviews the factors related to PM oxidation activity that the factors are divided into the engine-correlated and engine-uncorrelated factors. The methods with both advantages and disadvantages to test the oxidation behaviors are introduced. The microstructure and ingredient being fundamental factors affecting PM oxidation behaviors are as the principle line to correlate PM oxidation behaviors and engine-correlated factors. The relations of engine-correlated factors with oxidation behaviors are obtained though advanced technologies that are mutual complementation. The engine-uncorrelated factors are also reviewed that these factors are vital to oxidation activity changes. Multiple-factor analysis rather than single-factor analysis should be developed to make the oxidation behaviors of diesel PM more clear.