Bats aloft: variability in echolocation call structure at high altitudes

Bats alter their echolocation in response to changes in ecological and behavioral conditions, but little is known about how they adjust call structure in response to changes in altitude. We examined altitudinal variation in the echolocation of Brazilian free-tailed bats, Tadarida brasiliensis, a species known to fly to altitudes of 3,000 m above the ground. From 50.2 h of recordings, we analyzed 113 high-quality echolocation call sequences recorded from 0 to 862 m above ground level. Bats flying near the ground used shorter, higher-frequency, broader-bandwidth calls compared to bats at higher altitudes, an effect likely due to the greater levels of echo-producing clutter (i.e., vegetation, buildings) found near the ground. When ground-level recordings are excluded, bats continue to shift towards the use of longer-duration, lower-frequency, narrower-bandwidth calls with increasing altitude. We propose that the observed high-altitude changes in call structure are a response to changing acoustic attenuation rates and/or decreasing insect densities at higher altitudes.     

气候变化对淡水珍珠蚌种群的威胁

引言 在过去的100年中,淡水珍珠蚌Margaritfera margaritifera(L.)的数量在地球北区范围内已经下降到被IUCN列为濒危品种[1].人们认为主要原因是严重的工业污染和农业(有机)污染,采珠渔民的过度开采,寄主鲑科鱼类的减少,以及由于水力发电和河流管理计划的实施所造成的自然河床栖息环境的退化[2].     

Effect of ventilation rate on air cleanliness and energy consumption in operation rooms at rest

The interrelationships between ventilation rate, indoor air quality, and energy consumption in operation rooms at rest are yet to be understood. We investigate the effect of ventilation rate on indoor air quality indices and energy consumption in ORs at rest. The study investigates the air temperature, relative humidity, concentrations of carbon dioxide, particulate matter (PM), and airborne bacteria at different ventilation rates in operation rooms at rest of a medical center. The energy consumption and cost analysis of the heating, ventilating, and air conditioning (HVAC) system in the operation rooms at rest were also evaluated for all ventilation rates. No air-conditioned operation rooms had very highest PM and airborne bacterial concentrations in the operation areas. The bacterial concentration in the operation areas with 6–30 air changes per hour (ACH) was below the suggested level set by the United Kingdom (UK) for an empty operation room. A 70% of reduction in annual energy cost by reducing the ventilation rate from 30 to 6 ACH was found in the operation rooms at rest. Maintenance of operation rooms at ventilation rate of 6 ACH could save considerable amounts of energy and achieve the goal of air cleanliness.     

Recycling of cathode ray tube panel glasses as aggregates of concrete blocks and clay bricks

While the cathode ray tube (CRT) funnel containing lead could be transported to a smelting facility to recover lead, which could be an available option in domestic, a proper technology to recycle a CRT panel must be developed. Thus, it was suggested that CRT panel glass be used as aggregates of concrete blocks and clay bricks. Samples of blocks and bricks were fabricated with CRT powders and tested to measure their strength and absorption rate to determine their qualities, and environmental soundness was determined by measuring the leaching rate of hazardous metals. For concrete blocks, CRT panel glass powders incorporated as aggregates up to 40 % replacing stone powder was proposed as the proper condition for manufacturing blocks. Around 2 % of CRT panel incorporated into clay brick to substitute Kaoline was suggested to fabricate the best quality of clay brick. Results of leaching test met the criteria with much less concentration of hazardous metals, even lead compound containing in the CRT funnel. To conclude, the use of CRT panel powder after crushing it to the proper size as an aggregate of concrete blocks or clay bricks could be one of the appropriate alternatives to recycle for CRT glass waste being generated drastically in a short term.     

Carbon dioxide utilization with carbonation using industrial waste-desulfurization gypsum and waste concrete

In this study, we propose a process making calcium carbonate and calcium sulfate and recovering absorbent using ammonia absorbent, carbon dioxide, and industrial waste. The main objective of this study is to confirm the possibility of carbon capture and utilization based on waste materials. We assumed desulfurization gypsum and construction waste (ready mixed concrete washing water, waste concrete, etc.) are CaSO₄, Ca(OH)₂, respectively. And concentration of simulated carbon dioxide gas was 15 vol% similar to flue gas. Calcium carbonate was produced by combination reaction between ionic CO₂ in absorbent and metal ion in the solid waste. Experiments were conducted at normal temperature and pressure. Furthermore, the generated products were characterized by X-ray diffraction, and scanning electron microscope.     

Potential methane yield of food waste/food waste leachate from the biogasification facilities in South Korea

This study was to find out potential of methane yield on food waste and food waste leachate as biomass in Korea. The seven biogasification facilities were selected for comparison of theoretical methane yield and actual methane yield. The theoretical methane yield was calculated based on organic constituents (carbohydrate, protein, fat) and based on element analysis. The actual methane yield was investigated based on volatile solids and CODcr. Theoretical methane yields by organic constituents were 0.52 Sm³CH₄/kg VS and 0.35 Sm³CH₄/kg CODcr and these by element analysis were 0.53 Sm³CH₄/kg VS and 0.36 Sm³CH₄/kg CODcr. Actual methane yields were 0.36 Sm³CH₄/kg VS_in and 0.26 Sm³CH₄/kg CODcr_in. Considering the average removal efficiency of organic materials of seven FWL biogasification facilities, actual methane yields were 0.48 Sm³CH₄/kg VS_rem and 0.33 Sm³CH₄/kg CODcr_rem. Methane yield by organic constituents is very similar to that by element analysis and actual methane yields of volatile solids and CODcr were similar to theoretical value. The actual methane yield in this study showed approximated boundary values with previous other references which conducted in lab-scale or biochemical methane potential (BMP) tests. In conclusion, Korean food waste and food waste leachate have sufficient potential of methane yield in the ongoing biogasification facilities.     

Separation of selected PAHs by using high performance capillary electrophoresis with modifiers

The effect of varying SDS concentration in a micellar electrokinetic capillary chromatographic system (MECC) is investigated. In addition, the introduction of -cyclodextrin as modifier to the electrophoretic medium, containing SDS and a phosphate-borate buffer, is shown to give satisfactory separation of the seven selected PAHs. The separation efficiency is increased with the addition of -cyclodextrin.