Moisture buffering and effect of ventilation rate and volume rate of hygrothermal materials in a single room under steady state exterior conditions

In this paper, experiments and simulations investigating the moisture buffering of the gypsum boards are described. A test chamber was used for the experiments. The gypsum board was installed on the interior surface in the test chamber. This chamber was located in a climate chamber. The ambient condition of the chamber was controlled at constant temperature and humidity. In the experiment three cases of ventilation rate, no ventilation, 1.0 air change per hour and 5.0 air changes per hour, were investigated. In the experiment the relationship between moisture buffering and volume rate of the materials, various area and locations of the gypsum boards on the surrounding walls were investigated.     

A methodology for estimating airborne virus exposures in indoor environments using the spatial distribution of expiratory aerosols and virus viability characteristics

This study investigated the feasibility of using the spatial distribution of expiratory aerosols and the viability functions of airborne viruses to estimate exposures to airborne viruses in an indoor environment under imperfectly mixed condition. A method adopting this approach was tested in an air-conditioned hospital ward. Artificial coughs were produced by aerosolizing a simulated respiratory fluid containing a known concentration of benign bacteriophage. The bacteriophage exposures estimated on the basis of the spatial aerosol distributions and its viability function were in reasonable agreement with those measured directly by biological air sampling and culturing. The ventilation flow and coughing orientation were found to play significant roles in aerosol transport, leading to different spatial distribution patterns in bacteriophage exposure. Bacteriophage exposures decreased with lateral distance from the infector when the infector coughed vertically upward. In contrast, exposures were constant or even increased with distance in the case of lateral coughing. The possibility of incorporating the proposed exposure estimation into a dose-response model for infection risk assessment was discussed. The study has also demonstrated the potential application of viability functions of airborne viral pathogens in exposure assessment and infection risk analysis, which are often unavailable in literature for some important communicable diseases. PRACTICAL IMPLICATIONS: The proposed method makes use of the viability function of the virus and the spatial distribution of the expiratory aerosols for virus exposure estimation. Spatial differences in aerosol distribution and its influences on virus exposure in an air space can be determined. Variations in infectious dose with carrier aerosol size could also be considered. The proposed method may serve as a tool for further investigation of ventilation design and infection control in clinical or other indoor environments.     

Gaseous fluxes in the nitrogen and carbon budgets of subsurface flow constructed wetlands

In 2001 and 2002, fluxes of N(2)O, CH(4), CO(2) and N(2) were measured in two constructed wetlands (CW) for domestic wastewater treatment in Estonia. The difference between the median values of N(2)O, CH(4), and N(2) fluxes in the horizontal subsurface flow (HSSF) CWs was non-significant, being 1.3-1.4 and 1.4-4.1 mg m(-2) d(-1) for N(2)O-N and CH(4)-C, and 0.16-0.17 g N m(-2) d(-1) for N(2)-N respectively. The CO(2)-C flux was significantly lower (0.6 g C m(-2) d(-1)) in one of the HSSF filters of a hybrid CW, whereas the single HSSF and VSSF filters emitted 1.7 and 2.0 g C m(-2) d(-1). The median value of CH(4)-C emission in CWs varied from 1.4 to 42.6 g C m(-2) d(-1), being significantly higher in the VSSF filter beds. We also estimated C and N budgets in one of the HSSF CWs (312.5 m(2)) for 2001 and 2002. The total C input into this system was similar in 2001 and 2002, 772 and 719 kg C year(-1), but was differently distributed between constituent fluxes. In 2001, the main input flux was soil and microbial accumulation (663 kg C year(-1) or 85.8% of total C input), followed by plant net primary production (NPP) (10.2%) and wastewater inflow (3.9%). In 2002, 55.7% of annual C input was bound in plant NPP, whereas the increase in soil C formed 28.5% and wastewater inflow 15.7%. The main C output flux was soil respiration, including microbial respiration from soil and litter, and the respiration of roots and rhizomes. It formed 120 (97.5%) and 230 kg C year(-1) (98.2%) in 2001 and 2002 respectively. The measured CH(4)-C flux remained below 0.1% of total C output. The HSSF CW was generally found to be a strong C sink, and its annual C sequestration was 649 and 484 kg C year(-1) per wetland in 2001 and 2002 respectively. However, negative soil and microbial accumulation values in recent years indicate decreasing C sequestration. The average annual N removal from the system was 38-59 kg N year(-1) (46-48% of the initial total N loading). The most important flux of the N budget was N(2)-N emission (22.7 kg in 2001 and 15.2 kg in 2002), followed by plant belowground assimilation (2.3 and 11.9 kg N year(-1) in 2001 and 2002), and above-ground assimilation (1.9 and 9.2 kg N year(-1), respectively). N(2)O emission was low: 0.37-0.60 kg N year(-1)(.).     

Devastation of the environment by landslides activated by construction

Summary The landscape environment is presently formed by the system in which there are natural, as well as anthropogeneous components. There is natural direct and inverse relation between them. The possibility and method of construction of a technical work depends on specific natural conditions. Of decisive influence are mainly the rock relief, groundwater and geodynamic processes, which Matula (1976) terms the main components of the engineering geological environment. The natural conditions of the West Carpathians are suitable for the occurrence and development of slope movements. More than 3% of the total Slovakian area is covered by landslides and by other slope movements of a varied degree of activity. Based on actual examples of an incorrect procedure in erecting some of the ground, hydrotechnical and transport constructions the paper analyzes the causes of landslide reactivation and devastation of the environment. To avoid negative changes in the geological environment engineering geological documents are prepared for more important investment units, comprising predictions of changes induced by construction.

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Dégradation de l'environnement par la réactivation de glissements sous l'influence de constructions

Résumé Le paysage est le résultante de composants naturels, ainsi que d'influences anthropiques. Il y a un rapport mutuel direct et inverse entre ees facteurs. La possibilité de construire un ouvrage et les méthodes employées dépendent des conditions naturelles spécifiques. Les facteurs principaux sont la morphologie du site, l'eau souterraine et les phénomènes géodynamiques, que Matula M. (1976) appelle les composants principaux de l'environnement de la géologie de l'ingénieur. Les conditions naturelles des Carpates Occidentales se prêtent à l'apparition et au développement de mouvements de versants. Plus de 3% de la superficie totale de la Slovaquie sont concernés par des glissements et autres mouvements de versants d'une intensité variable. A partir d'exemples concrets de mauvaises réalisations de travaux souterrains, de barrages et d'infrastructures de transport, l'article analyse les causes de la réactivation des glissements et de la dégradation de l'environnement. Pour éviter ces influences négatives sur l'environnement géologique, on prépare des documents géologiques et géotechniques pour des travaux plus importants et qui incluent la prévision des changements provoqués par les constructions.

     

Investigating the unexposed surface temperature criteria of standard ASTM E119

Information and data were obtained to evaluate the unexposed surface temperature criteria of standard ASTM E119. The investigation consisted of: (1) reviewing literature to obtain information on the development of ASTM E119 and the unexposed surface temperature rise criteria, (2) conducting fire tests to obtain temperature data on slabs with various materials placed on the unexposed surface and (3) conducting ignition tests on these materials to obtain their approximate temperature at ignition. The information and data increased the knowledge concerning the relationship between the unexposed surface temperature rise criteria of ASTM E119 and the ignition temperature of common combustible materials.Winner of the 1985 Harry C. Bigglestone Award for Excellence in Written Communication of Fire Protection Concepts. Reference: Kenneth J. Schwartz and T. T. Lie, Investigating the Unexposed Surface Temperature Criteria of Standard ASTM E119,Fire Technology, Vol. 21, No. 3, August 1985, p. 169.     

Uptake of metal ions by chemically treated human hair

The uptake capacity of chemically treated human hair waste for the various metal ions can be arranged in the following decreasing order: Hg²⁺ (Hg⁺), Ag⁺, Pb²⁺, Cd²⁺, Cu²⁺ (Cu⁺), Cr⁶⁺, Ni²⁺, Cr³⁺.The uptake capacity is significantly affected by the presence of other metal ions. Anionic effect was found to be more pronounced for a mixed ions system than for a single ion system.     

Heavy metals in aquatic plants,clams, and sediments from the Chesapeake Bay,U.S.A. implications for waterfowl

Dry weight concentrations of cadmium, lead, copper and zinc were measured in clams, submerged aquatic macrophytes and sediments from several locations in the Chesapeake Bay region. Clam species included Macoma balthica, Mya arenaria, and Rangia cuneata; plant taxa included Najas spp., Potamogeton spp., Ruppia maritima, Vallisneria americana, and Zostera marina. Cadmium and lead concentrations were generally greater in whole plants than in soft tissues of clams, while the reverse was true for zinc; no marked trend was observed in copper concentrations. These results suggest that the changes occurring in the food habits of some Chesapeake Bay waterfowl towards increased clam utilization as a result of declining submerged plant abundances is not increasing ingestion of the nonessential metals cadmium and lead. Highest lead, copper and zinc concentrations were observed in sediments from the Patapsco River, which is probably due to the proximity of Baltimore Harbor. Highest cadmium concentrations were observed in sediments in the Port Tobacco River, a tributary of the Potomac River. These observations were generally consistent with high concentrations of the respective metal(s) in biota from these locations. Concentrations of the four metals in sediments were highly correlated to organic matter content.     

Insights into the reliability of different thermal conductivity measurement techniques: a thermo-geological study in Mære (Norway)

Thermal response tests (TRTs) are used to measure the effective thermal conductivity in boreholes. The results serve as a basis for the dimensioning of commercial ground-source heat pump installations with closed loop systems. The study evaluated the reliability of TRTs performed in winter by comparing two TRTs carried out under very different winter weather conditions. A third TRT elucidated the influence of convection in wells with a higher heat input. Rock cores were analysed for quartz content and these results and the laboratory-measured thermal conductivity data were compared with the TRT results. This highlighted the importance of the distribution and orientation of minerals in the rock, and that a high quartz content does not necessarily give high thermal conductivity values. It is concluded that winter TRTs give useful results if additional temperature loggers are installed in anticipated fracture zones to detect groundwater flow and to survey the effect of infiltrating water.     

新加坡启汇城Solaris大楼

本文项目获新加坡BCA绿色建筑白金奖项目名称:Solaris业主:Soilbuild PteLtd建设地点:新加坡启汇城方案设计:T.R.哈姆扎&杨经文建筑师事务所(www.trhamzahyeang.com)施工图设计:CPG Consultants PteLtd用地面积:7734m2建筑面积:3.2万m2结构形式:R.C.框架材料应用:R.C.框架,明矾遮阳篷,玻璃幕墙