The present work evaluated the deviations in the quality of steel reinforcing bars in terms of markings, diameter, yield strength and ductility in order to facilitate the drawing up of a yield strength value for the C...The present work evaluated the deviations in the quality of steel reinforcing bars in terms of markings, diameter, yield strength and ductility in order to facilitate the drawing up of a yield strength value for the Cameroon National Annex to Eurocode 2. The methodology of the work started with the collection of steel samples from various active building project sites in four different towns viz: Bamenda, Douala, Maroua and Yaoundé and testing their tensile strength and elongation using a Universal Testing Machine and also carrying out the bending test. Results show that bars without marked manufacturer’s name fell all the tests. Other results show that 52% of all the steel had yield stresses below 400 Mpa and the highest deviation in the yield strengths was 22.50%. The study recommends that properly marked grade 500 steel bars should be adopted in the Cameroon national annex to Eurocode 2.展开更多
America had been attempting to annex Canadian West and posed a threat to the security of the fledgling country. Therefore the antipathy towards America as well as independent-nation complex of Canadians drove Canadian...America had been attempting to annex Canadian West and posed a threat to the security of the fledgling country. Therefore the antipathy towards America as well as independent-nation complex of Canadians drove Canadian government to incorporate the west exploitation into the national strategy of creating an independent country. Canadian west exploitation thus took on some distinctiveness.展开更多
After investigation on the thermodynamic properties of a small number of binarymetallic melts, the structural units of which cannot be wholly determined by the cor-responding phase diagrams, it was found that they can...After investigation on the thermodynamic properties of a small number of binarymetallic melts, the structural units of which cannot be wholly determined by the cor-responding phase diagrams, it was found that they can be determined by the principleof annexation of two kinds of solutions in binary metallic melts. According to theprinciple of annexation, calculating models of mass action concentrations for severalbinary metallic melts have been formulated. The calculated results agree well withpractice, showing that this principle is a reliable basis for determination of the struc-tural units for some binary metallic melts.展开更多
Based on the phase diagrams, measured activities an the annexationprinciple, the calculating models of mass action concentrations forin-Pb-Ag and In-Bi-Sb ternary metallic melts have been formulated.The results of cal...Based on the phase diagrams, measured activities an the annexationprinciple, the calculating models of mass action concentrations forin-Pb-Ag and In-Bi-Sb ternary metallic melts have been formulated.The results of calculation both agree with practice, and obey the lawof mass action, showing that the models formulated can reflect thestructural reality of the corresponding melts and the annexationprinciple is applicable to the them.展开更多
Significance and theoretic foundation of "village relocation and annexation" in the planning of new countryside was elaborated. Planning schemes of New Pingdi and Xiangyunzhuang Village were analyzed from si...Significance and theoretic foundation of "village relocation and annexation" in the planning of new countryside was elaborated. Planning schemes of New Pingdi and Xiangyunzhuang Village were analyzed from six perspectives: selection of new village site, planning structure, planned road, architectural layout, public facilities and landscape design. It was then proposed that "village relocation and annexation" could not only save investment in public infrastructure, but also improve land use efficiency, thus it was an important approach of optimizing distribution of land resources.展开更多
Based on the measured activities, the phase diagrams and the annexation principle, the calculating models of mass action concentrations for Ag-Bi and Ag-Bi-In melts have been formulated. The calculated results agree w...Based on the measured activities, the phase diagrams and the annexation principle, the calculating models of mass action concentrations for Ag-Bi and Ag-Bi-In melts have been formulated. The calculated results agree with practice and obey the mass action law, showing that the models formulated can reflect the structural characteristics of both melts. Meanwhile, it confirms that annexation principle is applicable to the Ag-Bi-In metallic melts. The melts involving eulectic which give rise to phase separation, and in which activities exhibit positive deviation from Raoult's law is the basic cause of melts transforming from homogeneous to heterogeneous ones.展开更多
The electrical instability that frequently distinguishes the isolated networks and depends on diesel generators to supply their energy requirements leads to an operation of the diesel generator in a transient dynamic ...The electrical instability that frequently distinguishes the isolated networks and depends on diesel generators to supply their energy requirements leads to an operation of the diesel generator in a transient dynamic condition and/or at low loads. In addition, extended operation of the diesel generator at partial load develops the condensation of combustion residues on the engine cylinder walls, which, after a certain time, increases friction, reduces the efficiency of the equipment and increases its fuel consumption. On the other hand, recent regulatory changes have led to ever more stringent and evolving emission standards. Among these, the International Maritime Organization (IMO) and the Environmental Protection Agency (EPA) have implemented emission standards in order to reduce exhaust gas emitted by marine diesel engines. To phase lower emission engines as soon as possible, a Tier system was adopted. This paper presents a literature review of existing technologies available to optimize the energy performance of diesel engines and diesel generators in order to reduce the cost of electricity, to increase the diesel engine efficiency and to decrease their fuel consumption and greenhouse gases (GHG) emissions. The proposed optimization methodologies are based on the application of Pre-treatment, Internal treatment and Post-treatment technologies for diesel engines and on the application of mechanical and electrical technologies for diesel power generators (DPGs). The list of references given at the end of the paper should offer aids for students and researchers working in this field.展开更多
Nowadays,building energy models(BEMs)are widely used,particularly in the assessment of energy consumption in buildings to address the potential savings that can be generated.The realisation of a dynamic energy model b...Nowadays,building energy models(BEMs)are widely used,particularly in the assessment of energy consumption in buildings to address the potential savings that can be generated.The realisation of a dynamic energy model based on high-fidelity physics(white-box models)requires a tuning process to fit the model to reality,due to many uncertainties involved.Currently some research trends try to reduce this performance gap by modulating different types of experimental parameters such as:capacitances or infiltration.The EnergyPlus simulation software,in its latest versions,has implemented an object:HybridModel:Zone that calculates the infiltration and internal mass of buildings using an inverse modelling approach that employs only the measured indoor temperature data to invert the heat balance equation for the zone under study.The main objective of this paper is to reduce the execution time and uncertainties in the development of quality energy models by generating a new calibration methodology that implements this approach.This uses,as a starting point,a research created by the authors of this study,which was empirically and comparatively validated against the energy models developed by the participants in Annex 58.It is also worth highlighting the empirical validation of the HybridModel:Zone object,since it was activated in all scenarios where its execution is possible:periods of seven days or more of free oscillation and periods in which the building is under load.The findings are promising.The data generated with the new methodology,if compared with those produced by the baseline model,improve their resemblance to the real ones by 22.9%.While those of its predecessor did it by 15.6%.For this study,the two dwellings foreseen in Annex 58 of the IEA ECB project have been modelled and their real monitoring data have been used.展开更多
On July 3,2017,NSFC president Yang Wei and Prof.Sergey Gaponenko,chairman of the scientific council of the Belarusian Republican Foundation for Fundamental Research(BRFFR)signed the Annex to the Agreement on Cooperati...On July 3,2017,NSFC president Yang Wei and Prof.Sergey Gaponenko,chairman of the scientific council of the Belarusian Republican Foundation for Fundamental Research(BRFFR)signed the Annex to the Agreement on Cooperation between the National Natural Science Foundation of China and the Belarusian Republican Foundation for Fundamental Researchin Beijing.展开更多
文摘The present work evaluated the deviations in the quality of steel reinforcing bars in terms of markings, diameter, yield strength and ductility in order to facilitate the drawing up of a yield strength value for the Cameroon National Annex to Eurocode 2. The methodology of the work started with the collection of steel samples from various active building project sites in four different towns viz: Bamenda, Douala, Maroua and Yaoundé and testing their tensile strength and elongation using a Universal Testing Machine and also carrying out the bending test. Results show that bars without marked manufacturer’s name fell all the tests. Other results show that 52% of all the steel had yield stresses below 400 Mpa and the highest deviation in the yield strengths was 22.50%. The study recommends that properly marked grade 500 steel bars should be adopted in the Cameroon national annex to Eurocode 2.
文摘America had been attempting to annex Canadian West and posed a threat to the security of the fledgling country. Therefore the antipathy towards America as well as independent-nation complex of Canadians drove Canadian government to incorporate the west exploitation into the national strategy of creating an independent country. Canadian west exploitation thus took on some distinctiveness.
文摘After investigation on the thermodynamic properties of a small number of binarymetallic melts, the structural units of which cannot be wholly determined by the cor-responding phase diagrams, it was found that they can be determined by the principleof annexation of two kinds of solutions in binary metallic melts. According to theprinciple of annexation, calculating models of mass action concentrations for severalbinary metallic melts have been formulated. The calculated results agree well withpractice, showing that this principle is a reliable basis for determination of the struc-tural units for some binary metallic melts.
文摘Based on the phase diagrams, measured activities an the annexationprinciple, the calculating models of mass action concentrations forin-Pb-Ag and In-Bi-Sb ternary metallic melts have been formulated.The results of calculation both agree with practice, and obey the lawof mass action, showing that the models formulated can reflect thestructural reality of the corresponding melts and the annexationprinciple is applicable to the them.
文摘Significance and theoretic foundation of "village relocation and annexation" in the planning of new countryside was elaborated. Planning schemes of New Pingdi and Xiangyunzhuang Village were analyzed from six perspectives: selection of new village site, planning structure, planned road, architectural layout, public facilities and landscape design. It was then proposed that "village relocation and annexation" could not only save investment in public infrastructure, but also improve land use efficiency, thus it was an important approach of optimizing distribution of land resources.
文摘Based on the measured activities, the phase diagrams and the annexation principle, the calculating models of mass action concentrations for Ag-Bi and Ag-Bi-In melts have been formulated. The calculated results agree with practice and obey the mass action law, showing that the models formulated can reflect the structural characteristics of both melts. Meanwhile, it confirms that annexation principle is applicable to the Ag-Bi-In metallic melts. The melts involving eulectic which give rise to phase separation, and in which activities exhibit positive deviation from Raoult's law is the basic cause of melts transforming from homogeneous to heterogeneous ones.
文摘The electrical instability that frequently distinguishes the isolated networks and depends on diesel generators to supply their energy requirements leads to an operation of the diesel generator in a transient dynamic condition and/or at low loads. In addition, extended operation of the diesel generator at partial load develops the condensation of combustion residues on the engine cylinder walls, which, after a certain time, increases friction, reduces the efficiency of the equipment and increases its fuel consumption. On the other hand, recent regulatory changes have led to ever more stringent and evolving emission standards. Among these, the International Maritime Organization (IMO) and the Environmental Protection Agency (EPA) have implemented emission standards in order to reduce exhaust gas emitted by marine diesel engines. To phase lower emission engines as soon as possible, a Tier system was adopted. This paper presents a literature review of existing technologies available to optimize the energy performance of diesel engines and diesel generators in order to reduce the cost of electricity, to increase the diesel engine efficiency and to decrease their fuel consumption and greenhouse gases (GHG) emissions. The proposed optimization methodologies are based on the application of Pre-treatment, Internal treatment and Post-treatment technologies for diesel engines and on the application of mechanical and electrical technologies for diesel power generators (DPGs). The list of references given at the end of the paper should offer aids for students and researchers working in this field.
基金funded by the Government of Navarra under the project“From BIM to BEM:B&B”(ref.0011-1365-2020-000227).
文摘Nowadays,building energy models(BEMs)are widely used,particularly in the assessment of energy consumption in buildings to address the potential savings that can be generated.The realisation of a dynamic energy model based on high-fidelity physics(white-box models)requires a tuning process to fit the model to reality,due to many uncertainties involved.Currently some research trends try to reduce this performance gap by modulating different types of experimental parameters such as:capacitances or infiltration.The EnergyPlus simulation software,in its latest versions,has implemented an object:HybridModel:Zone that calculates the infiltration and internal mass of buildings using an inverse modelling approach that employs only the measured indoor temperature data to invert the heat balance equation for the zone under study.The main objective of this paper is to reduce the execution time and uncertainties in the development of quality energy models by generating a new calibration methodology that implements this approach.This uses,as a starting point,a research created by the authors of this study,which was empirically and comparatively validated against the energy models developed by the participants in Annex 58.It is also worth highlighting the empirical validation of the HybridModel:Zone object,since it was activated in all scenarios where its execution is possible:periods of seven days or more of free oscillation and periods in which the building is under load.The findings are promising.The data generated with the new methodology,if compared with those produced by the baseline model,improve their resemblance to the real ones by 22.9%.While those of its predecessor did it by 15.6%.For this study,the two dwellings foreseen in Annex 58 of the IEA ECB project have been modelled and their real monitoring data have been used.
文摘On July 3,2017,NSFC president Yang Wei and Prof.Sergey Gaponenko,chairman of the scientific council of the Belarusian Republican Foundation for Fundamental Research(BRFFR)signed the Annex to the Agreement on Cooperation between the National Natural Science Foundation of China and the Belarusian Republican Foundation for Fundamental Researchin Beijing.
