Mud bricks were made in Egypt from the Nile silt, which is a mixture of clay and sand, which is sometimes mixed with pieces of organic materials and then mixed with water to make mud bricks, the oldest mud bricks were...Mud bricks were made in Egypt from the Nile silt, which is a mixture of clay and sand, which is sometimes mixed with pieces of organic materials and then mixed with water to make mud bricks, the oldest mud bricks were found in tombs dating back to Naqada and in Abydos, and parts of the central state pyramids were built from it, geological study and hydrogeology of the site were studied, mud bricks were studied by XRD and SEM, the main components and properties were studied, the mud bricks were made according to a local technique in industry and construction, the walls of Karnak temple become weak fragile materials due to their exposure to various damaging factors, the study put a recommended treatment of damaged mud bricks walls which surrounded of Karnak temple.展开更多
Clay brick masonry unit(CBMU) walls are widely used in building structures,and its damage and protection under explosion loads have been a matter of concern in the field of engineering protection.In this paper,a serie...Clay brick masonry unit(CBMU) walls are widely used in building structures,and its damage and protection under explosion loads have been a matter of concern in the field of engineering protection.In this paper,a series of full-scale experiments of the response characteristics of 24 cm CMBU walls unreinforced and reinforced with polyurea elastomer subjected to blast loading were carried out.Through setting 5.0 kg TNT charges at different stand-off distances,the damage characteristics of masonry walls at different scaled distances were obtained.The reinforcement effect of different polyurea coating thicknesses and methods on the blast resistance performance of masonry walls under single and repeated loads were also explored.Five failure grades were summarized according to the dynamic response features of masonry walls.Based on the stress wave propagation pattern in multi-media composite structures,the internal stress distribution of masonry walls were analyzed,and the division basis of the masonry walls’ failure grades was then quantified.Combined with Scanning Electron Microscope(SEM)images,the deformation characteristics of soft and hard segments of polyurea and effects of detonation products on microstructures were revealed respectively,which provides an important reference for the design and application of polyurea in the blast resistance of clay brick masonry walls.展开更多
One new coordination polymer with the chemical formula [CoCu2L2·K2·1.5C2H5OH]n（H4L = 2-hydroxy-3-[（E）-（{3-[（2-hydroxybenzoyl）amino]propyl}imino）methyl] benzoic acid） has been synthesized based on the...One new coordination polymer with the chemical formula [CoCu2L2·K2·1.5C2H5OH]n（H4L = 2-hydroxy-3-[（E）-（{3-[（2-hydroxybenzoyl）amino]propyl}imino）methyl] benzoic acid） has been synthesized based on the slow diffusion method,and characterized by IR spectroscopy,thermalgravimetric and X-ray diffraction analysis.It crystallizes in the monoclinic system,space group P21/n with a = 11.98860（10）,b = 24.4279（3）,c = 14.9008（2） ,β = 104.7490（10）°,V = 4220.01（8） 3,Z = 2,Mr = 1009.94,Dc = 1.590 g/cm3,F（000） = 2056,μ（MoKα） = 1.649 mm-1,the final R = 0.0411 and wR = 0.1178 for 5920 observed reflections with I 2σ（I）.The compound possesses a 2D brick wall structure constructed from trinuclear units.展开更多
According to the container recycling institute,nearly a million plastic beverage bottles are sold every minute around the world.Plastic bottles are considered as an urban junk,however,it has shape characteristics whic...According to the container recycling institute,nearly a million plastic beverage bottles are sold every minute around the world.Plastic bottles are considered as an urban junk,however,it has shape characteristics which make them usable in construction in lieu of conventional bricks.This research promotes the use of recycled plastic bottles as eco-bricks by substituting it with the typical construction bricks.It evaluates the thermal performance of sand filled plastic bottle-walls in a comparative analysis with traditional composite brick walls.The thermal performance of the plastic bottle walls was evaluated through COMSOL®Multi-physics and the results are noted.展开更多
Given the high demand for low-cost housing by the low-income earners,coupled with the tropical climate expe-rienced in sub-Saharan Africa,new-built housing stock needs utmost attention to cost,durability,and efficienc...Given the high demand for low-cost housing by the low-income earners,coupled with the tropical climate expe-rienced in sub-Saharan Africa,new-built housing stock needs utmost attention to cost,durability,and efficiency.With the walls accounting for a substantial proportion of the total building cost,choice of a wall system for use in building construction is critical.This choice usually depends on how durable,comfortable,ecological,and economical a given system is,to meet both the quality standards and low-cost aspects of housing.Although the earthbag building system allows for the construction of strong,affordable,and sustainable housing,it is not widely known.As such,its sustainable characteristics have gone unrecognised throughout the building industry.This paper examines and compares the thermal properties and total Life Cycle Costs(LCC)of earthbag walls with the commonly used burnt brick walls-based on the Degree-Days method and Life Cycle Costing analyses of building walls located in one of the hottest regions in Uganda.In-situ measurements of temperature and heat flux were conducted in accordance with ISO 9869 and the annual energy requirements obtained.The total LCC were calculated based on the initial construction costs and annual energy costs attributed to the building wall systems.Earthbags housing was found to be thermal-physically better than the brick wall with a lower U-value resulting in lower annual energy requirements and a huge saving in annual energy costs of up to 83.2%.This saving,coupled with low initial construction costs made the earthbag unit 68.7%cheaper than the burnt brick unit over a 30-year period.Therefore,this study findings suggest earthbag walling system as an economically viable and technically feasible low-cost construction option for rural areas and low-incomers earners’housing in warm climatic conditions,a characteristic of sub-Saharan countries-so as to promote regional development.展开更多
This paper presents three-dimensional finite element （FE） analyses of an all-frame model of a three-story reinforced concrete （RC） building damaged in the 1999 Taiwan Chi-Chi Earthquake. Non-structural brick walls...This paper presents three-dimensional finite element （FE） analyses of an all-frame model of a three-story reinforced concrete （RC） building damaged in the 1999 Taiwan Chi-Chi Earthquake. Non-structural brick walls of the building acted as a seismic resistant element although their contributions were neglected in the design. Hence, the entire structure of a typical frame was modeled and static and dynamic nonlinear analyses were conducted to evaluate the contributions of the brick walls. However, the results of the analyses were considerably overestimated due to coarse mesh discretizations, which were unavoidable due to limited computer resources. This study corrects the overestimations by modifying （1） the tensile strengths and （2） shear stiffness reduction factors of concrete and brick. The results indicate that brick walls improve frame strength although shear failures are caused in columns shortened by spandrel walls. Then, the effectiveness of three types of seismic retrofits is evaluated. The maximum drift of the first floor is reduced by 89.3%, 94.8%, and 27.5% by Steel-confined, FuI1-RC, and Full-brick models, respectively. Finally, feasibility analyses of models with soils were conducted. The analyses indicated that the soils elongate the natural period of building models although no significant differences were observed.展开更多
In accordance with the holographic principle, by counting the states of the scalar field just at the event horizon of the Vaidya-Bonner black hole, the holographic entropy bound of the black hole is calculated and the...In accordance with the holographic principle, by counting the states of the scalar field just at the event horizon of the Vaidya-Bonner black hole, the holographic entropy bound of the black hole is calculated and the Bekenstein- Hawking formula is obtained, With the generalized uncertainty principle, the divergence of state density at event horizon in the ordinary quantum field theory is removed, With the residue theorem, the integral trouble in the calculation is overcome. The present result is quantitatively tenable and the holographic principle is realized by applying the quantum field theory to the black hole entropy problem. Compared with some previous works, it is suggested that the quantum states contributing to black hole entropy should be restricted on the event horizon.展开更多
We extend Parikh＇s recent work to the arbitrarily dimensional Schwarzschild black holes whose Arnowitt-Deser-Misner （ADM） mass is identical to its mass parameter. We view Hawking radiation as a tunnelling process a...We extend Parikh＇s recent work to the arbitrarily dimensional Schwarzschild black holes whose Arnowitt-Deser-Misner （ADM） mass is identical to its mass parameter. We view Hawking radiation as a tunnelling process across the event horizon. From the tunnelling probability we also find a leading correction to the semiclassical emission rate. The result consists with an underlying unitary theory.展开更多
This paper presents an experimental investigation on the flexural behavior of cross-connected brick masonry infill wall panels supported on reinforced concrete beam grids above and below the walls.The experimental pro...This paper presents an experimental investigation on the flexural behavior of cross-connected brick masonry infill wall panels supported on reinforced concrete beam grids above and below the walls.The experimental program was comprised of six wall systems.The effect of change in lower beam stiffness relative to the wall and the geometry of the main walls were investigated.From the results of the experimental tests,the increase in the depth of the lower beam grid reduces the deflection,resulting in an increase in the load carrying capacity of the wall.Further,the stiffness of the main walls affects the deflection and the failure load of the cross walls.展开更多
文摘Mud bricks were made in Egypt from the Nile silt, which is a mixture of clay and sand, which is sometimes mixed with pieces of organic materials and then mixed with water to make mud bricks, the oldest mud bricks were found in tombs dating back to Naqada and in Abydos, and parts of the central state pyramids were built from it, geological study and hydrogeology of the site were studied, mud bricks were studied by XRD and SEM, the main components and properties were studied, the mud bricks were made according to a local technique in industry and construction, the walls of Karnak temple become weak fragile materials due to their exposure to various damaging factors, the study put a recommended treatment of damaged mud bricks walls which surrounded of Karnak temple.
基金supported by the National Natural Science Foundation of China nos.51978660。
文摘Clay brick masonry unit(CBMU) walls are widely used in building structures,and its damage and protection under explosion loads have been a matter of concern in the field of engineering protection.In this paper,a series of full-scale experiments of the response characteristics of 24 cm CMBU walls unreinforced and reinforced with polyurea elastomer subjected to blast loading were carried out.Through setting 5.0 kg TNT charges at different stand-off distances,the damage characteristics of masonry walls at different scaled distances were obtained.The reinforcement effect of different polyurea coating thicknesses and methods on the blast resistance performance of masonry walls under single and repeated loads were also explored.Five failure grades were summarized according to the dynamic response features of masonry walls.Based on the stress wave propagation pattern in multi-media composite structures,the internal stress distribution of masonry walls were analyzed,and the division basis of the masonry walls’ failure grades was then quantified.Combined with Scanning Electron Microscope(SEM)images,the deformation characteristics of soft and hard segments of polyurea and effects of detonation products on microstructures were revealed respectively,which provides an important reference for the design and application of polyurea in the blast resistance of clay brick masonry walls.
基金Supported by the Technology Chamber of Henan Province (092300410031)the Education Chamber of Henan Province (2009A150005)
文摘One new coordination polymer with the chemical formula [CoCu2L2·K2·1.5C2H5OH]n（H4L = 2-hydroxy-3-[（E）-（{3-[（2-hydroxybenzoyl）amino]propyl}imino）methyl] benzoic acid） has been synthesized based on the slow diffusion method,and characterized by IR spectroscopy,thermalgravimetric and X-ray diffraction analysis.It crystallizes in the monoclinic system,space group P21/n with a = 11.98860（10）,b = 24.4279（3）,c = 14.9008（2） ,β = 104.7490（10）°,V = 4220.01（8） 3,Z = 2,Mr = 1009.94,Dc = 1.590 g/cm3,F（000） = 2056,μ（MoKα） = 1.649 mm-1,the final R = 0.0411 and wR = 0.1178 for 5920 observed reflections with I 2σ（I）.The compound possesses a 2D brick wall structure constructed from trinuclear units.
文摘According to the container recycling institute,nearly a million plastic beverage bottles are sold every minute around the world.Plastic bottles are considered as an urban junk,however,it has shape characteristics which make them usable in construction in lieu of conventional bricks.This research promotes the use of recycled plastic bottles as eco-bricks by substituting it with the typical construction bricks.It evaluates the thermal performance of sand filled plastic bottle-walls in a comparative analysis with traditional composite brick walls.The thermal performance of the plastic bottle walls was evaluated through COMSOL®Multi-physics and the results are noted.
文摘Given the high demand for low-cost housing by the low-income earners,coupled with the tropical climate expe-rienced in sub-Saharan Africa,new-built housing stock needs utmost attention to cost,durability,and efficiency.With the walls accounting for a substantial proportion of the total building cost,choice of a wall system for use in building construction is critical.This choice usually depends on how durable,comfortable,ecological,and economical a given system is,to meet both the quality standards and low-cost aspects of housing.Although the earthbag building system allows for the construction of strong,affordable,and sustainable housing,it is not widely known.As such,its sustainable characteristics have gone unrecognised throughout the building industry.This paper examines and compares the thermal properties and total Life Cycle Costs(LCC)of earthbag walls with the commonly used burnt brick walls-based on the Degree-Days method and Life Cycle Costing analyses of building walls located in one of the hottest regions in Uganda.In-situ measurements of temperature and heat flux were conducted in accordance with ISO 9869 and the annual energy requirements obtained.The total LCC were calculated based on the initial construction costs and annual energy costs attributed to the building wall systems.Earthbags housing was found to be thermal-physically better than the brick wall with a lower U-value resulting in lower annual energy requirements and a huge saving in annual energy costs of up to 83.2%.This saving,coupled with low initial construction costs made the earthbag unit 68.7%cheaper than the burnt brick unit over a 30-year period.Therefore,this study findings suggest earthbag walling system as an economically viable and technically feasible low-cost construction option for rural areas and low-incomers earners’housing in warm climatic conditions,a characteristic of sub-Saharan countries-so as to promote regional development.
文摘This paper presents three-dimensional finite element （FE） analyses of an all-frame model of a three-story reinforced concrete （RC） building damaged in the 1999 Taiwan Chi-Chi Earthquake. Non-structural brick walls of the building acted as a seismic resistant element although their contributions were neglected in the design. Hence, the entire structure of a typical frame was modeled and static and dynamic nonlinear analyses were conducted to evaluate the contributions of the brick walls. However, the results of the analyses were considerably overestimated due to coarse mesh discretizations, which were unavoidable due to limited computer resources. This study corrects the overestimations by modifying （1） the tensile strengths and （2） shear stiffness reduction factors of concrete and brick. The results indicate that brick walls improve frame strength although shear failures are caused in columns shortened by spandrel walls. Then, the effectiveness of three types of seismic retrofits is evaluated. The maximum drift of the first floor is reduced by 89.3%, 94.8%, and 27.5% by Steel-confined, FuI1-RC, and Full-brick models, respectively. Finally, feasibility analyses of models with soils were conducted. The analyses indicated that the soils elongate the natural period of building models although no significant differences were observed.
基金Supported by the National Natural Science Foundation of China under Grant No 10375008, and the National Basic Research Programme of China under Grant No 2003CB716300.
文摘In accordance with the holographic principle, by counting the states of the scalar field just at the event horizon of the Vaidya-Bonner black hole, the holographic entropy bound of the black hole is calculated and the Bekenstein- Hawking formula is obtained, With the generalized uncertainty principle, the divergence of state density at event horizon in the ordinary quantum field theory is removed, With the residue theorem, the integral trouble in the calculation is overcome. The present result is quantitatively tenable and the holographic principle is realized by applying the quantum field theory to the black hole entropy problem. Compared with some previous works, it is suggested that the quantum states contributing to black hole entropy should be restricted on the event horizon.
基金Supported by the National Natural Science Foundation of China under Grand Nos 10373003 and 10475013, and the National Basic Research Program of China under Grant No 2003CB716300.
文摘We extend Parikh＇s recent work to the arbitrarily dimensional Schwarzschild black holes whose Arnowitt-Deser-Misner （ADM） mass is identical to its mass parameter. We view Hawking radiation as a tunnelling process across the event horizon. From the tunnelling probability we also find a leading correction to the semiclassical emission rate. The result consists with an underlying unitary theory.
文摘This paper presents an experimental investigation on the flexural behavior of cross-connected brick masonry infill wall panels supported on reinforced concrete beam grids above and below the walls.The experimental program was comprised of six wall systems.The effect of change in lower beam stiffness relative to the wall and the geometry of the main walls were investigated.From the results of the experimental tests,the increase in the depth of the lower beam grid reduces the deflection,resulting in an increase in the load carrying capacity of the wall.Further,the stiffness of the main walls affects the deflection and the failure load of the cross walls.
