超出生体重児に対する早期デキサメサゾン投与の有用性 : National Institute of Child Health and Human Development Neonatal research Network報告 (海外誌掲載論文の和文概要とそれに対するコメント)

Rice husk (RH), an agricultural waste, is abundantly available in rice producing countries like China, India, Bangladesh, Brazil, US, Cambodia, Vietnam, Myanmar, and South East Asia. Despite the massive amount of annual production worldwide, so far RHs have been recycled only for low-value applications. In recent years, many rice mills in rice producing countries have started using RH for the energy production for mill operations as well as household lighting in rural regions. Burning of RHs produces the rice husk ash (RHA). The disposal in landfills or open fields can be problematic and may cause a serious environmental and human health related problems due to the low bulk density of RHA. Several ways are being thought of for disposing RHA by making its commercial use. The amorphous silica forms the main component (83–90%) of RHA. The amorphous silica rich RHA has wide range of applications. High-value applications and current research investigations such as the use of RHA in manufacturing of silica gels, silicon chip, synthesis of activated carbon and silica, production of light weight construction materials and insulation, catalysts, zeolites, ingredients for lithium ion batteries, graphene, energy storage/capacitor, carbon capture, and in drug delivery vehicles are presented. Use of RHA in potential future applications is also discussed. It is suggested that the amorphous silica rich RHA could become a potential resource of low cost precursor for the production of value-added silica based materials for practical applications.

Potential applications of rice husk ash waste from rice husk biomass power plant

https://ecommons.aku.edu/cgi/viewcontent.cgi?article=1695&context=pakistan_fhs_mc_women_childhealth_paediatr

Causes and incidence of community-acquired serious infections among young children in south Asia (ANISA): an observational cohort study

Ultra-high strength concrete made with recycled aggregate from sanitary ceramic wastes – The method of production and the interfacial transition zone

The findings of a current research project entitled Thermal Effects in Concrete Bridge Superstructures are highlighted. The research project is sponsored by NCHRP. A brief discussion of the mechanisms of heat transfer as they relate to bridge structures is presented, including the thermal coefficients of various types of different concrete composed of different aggregates. Also included are brief discussions on mean effective bridge temperatures, temperature differentials, and the response analysis for nonlinear temperature gradients. Two case studies of longitudinal thermal response selected from those conducted in the research from those conducted in the research project are included in this paper. The thermal gradients used in New Zealand, England, and Ontario, Canada, plus those recommended by the Post-Tensioning Institute, are included in the reesponse analysis. In addition, specific recommendations for improving the U.S. design provisions for thermal effects are included. (Author)

Thermal effects in concrete bridge superstructures

An investigation was conduced to achieve concrete of higher strength using crushed brick as aggregate and study the mechanical properties. It was found that higher strength concrete ( c f  = 4500 to 6600 psi 1 ) with brick aggregate is achievable whose strength is much higher than the parent uncrushed brick. Test results show that the compressive strength of brick aggregate concrete can be increased by decreasing its water-cement ratio and using admixture whenever necessary for workability. The compressive strength as well as the tensile strength and the modulus of elasticity of the concrete were studied. The cylinder strength is found about 90% of the cube strength. The ACI Code relations for determining the modulus of rupture was found to highly underestimate the test values., whereas the code suggested expression for elastic modulus gives much higher values than the experimental ones for brick aggregate concrete. Relations were proposed to estimate the modulus of rupture and the modulus of elasticity of brick aggregate concrete of higher strengths.

Properties of higher strength concrete made with crushed brick as coarse aggregate

Rice husk ash (RHA) obtained from uncontrolled combustion was used as an alternate construction material for concrete and bricks. Each year large quantity of RHA produced and is an environmental concern. However, RHA contains silicate which is in turn a characteristic of pozzolanic materials. Attempt has been made to use this RHA as a cement replacement for concrete and clay replacement for bricks. Experimental results on concrete and bricks were presented in a normalized way. Normalization was done based on the control specimen i.e. specimen does not contain any RHA. Economic constraint restraints the rural people from conventional constructional materials, however, RHA which is abandoned in rural area can offer a solution. From the normalized plot one can estimate the percentage of RHA that can be used based on the load demand. The objective of this study was to shed light on the utilization potential of RHA as a construction material. The study of economic impact of RHA is beyond the scope of this study.

Utilization potential of rice husk ash as a construction material in rural areas

The temperature of a structure exposed to the atmosphere depends on many factors such as geographical location, climatological condition, structure’s orientation, materials and surface condition, a...

Structural effects of temperature gradient on a continuous prestressed concrete girder bridge: analysis and field measurements

BACKGROUND The Aetiology of Neonatal Infection in South Asia (ANISA) study takes advantage of text messaging technology to record information required for randomizing the study population into a control subcohort. The text message system is also used for monitoring various study activities. METHODS When a child-health worker registers a newborn in the study, she sends a text message to a database server containing the study identification number and newborn's age at the time of registration. For each possible serious bacterial infection case, a study physician also sends a text message to the same server with the age of the young infant at the time of illness assessment. Using this information, a computer-based algorithm randomizes the newborn into a control subcohort. Text messages are also sent to alert the study physicians and study supervisors of a possible serious bacterial infection case being referred to health-care facilities. Phlebotomists working at remote specimen collection sites send text messages to the site laboratory personnel before sending the specimens through porters. DISCUSSION Real-time data entry and monitoring are challenging for any population-based study conducted in remote areas. Our text messaging system provides an opportunity to overcome this barrier where availability of data entry facilities is limited.

Using Text Messages for Critical Real-time Data Capture in the ANISA Study.

A live-load test and a three-dimensional (3D) finite-element (FE) model of a three-span continuous prestressed–concrete girder bridge are described in this paper. The precast prestressed-concrete simple-span girders are made continuous by pouring a continuity diaphragm between the girders ends. Special reinforcement is extended from the girders’ bottom flanges into the diaphragm to ensure continuity under positive moments that result from time-dependent effects such as creep, shrinkage, and temperature gradient. This detail was adopted in a recently constructed bridge. The bridge has been instrumented with embedded and surface-mounted sensors and was monitored for over 2 years to evaluate the performance of the new continuity detail. A live-load test was carried out to evaluate the response of the new detail under truck loads. Field test data were used to validate a 3D FE model that was developed for the entire monitored segment. Once the FE model was validated, it was used to investigate the effi...

Tanvir Hossain

Papers

Properties of higher strength concrete made with crushed brick as coarse aggregate

Utilization potential of rice husk ash as a construction material in rural areas

Structural effects of temperature gradient on a continuous prestressed concrete girder bridge: analysis and field measurements

Using Text Messages for Critical Real-time Data Capture in the ANISA Study.

Field Test and Finite-Element Modeling of a Three-Span Continuous-Girder Bridge