Affordable passive solar design in a temperate climate: An experiment in residential building orientation

Improved energy efficiency in new residential buildings is typically being sought across the developed world through changing requirements in building and/or planning regulations. Stringency is set to further increase significantly in attempts to meet climate change mitigation goals. However, new regulation is usually met with reticence from sectors of the building industry, one reason being the additional costs implied in meeting higher performance standards for more energy efficient buildings. One low cost option, investigated in this paper, is to orient buildings in order to maximise their passive solar benefits. Using a range of 81 different detached dwelling designs, a modelling experiment was conducted in order to assess the implications of orientation on modelled thermal energy efficiency. Design adaptability to orientation change was modelled across two scenarios; current building energy efficiency standards and pending improved energy efficiency standards. The effect of size and overall energy efficiency rating was included in consideration of variance across orientations. Results show that higher standards are easier to apply to smaller dwellings, and costs are lower. Also, higher performing designs are more flexible across different orientations, producing lower standard deviations of mean ratings. The findings indicate that passive solar design is a concept that can readily be incorporated into house plans at the design stage. Recommendations for further empirical research are also made.     

On the feasibility of community-scale photovoltaic-powered reverse osmosis desalination systems for remote locations

This paper presents a generalized methodology to evaluate the feasibility of photovoltaic-powered reverse osmosis (PVRO) systems for small, remote communities in challenging environments. The economic feasibility is determined by comparing the cost of water from a photovoltaic reverse osmosis system with the cost of water obtained using conventional diesel-powered reverse osmosis. For PVRO systems, the feasibility is a function of location due to variation in solar resource, water type, system demand and local governmental policies. A series of sample cases were analyzed to demonstrate the method. Analysis for community-scale seawater reverse osmosis systems was carried out for various locations using Geographic Information System (GIS) data. A site-specific analysis has been completed for seawater and brackish water reverse osmosis systems. It was found that photovoltaic-powered reverse osmosis is feasible for the majority of remote locations with a large solar resource.     

Combustion of fine aluminum and magnesium powders in water

Micron-sized metal powders carried by a nitrogen flow were fed along the axis of a cylindrical hydrogen/oxygen diffusion flame. The particles ignited and burned in the water vapor at approximately 2500 K. Experiments were performed at atmospheric pressure. The environment in which particles burned was characterized in detail using computational fluid dynamics. The computations confirmed that the metal powders burned in water while the effect of oxygen and other oxidizing species could be neglected. Combustion was characterized experimentally for micron-sized powders of both aluminum and magnesium. Particle size distributions were measured using low-angle laser light scattering. Optical emission of the burning particles was recorded using filtered photomultiplier tubes. Measured durations of individual particle emission pulses were assumed to represent their burn times; these data were classified into logarithmically spaced time bins. The distribution of the particle burn times was correlated with their size distributions assuming that larger size particles burned longer. It was observed that correlation between the burn times, t, and particle diameters, D, can be approximately described as t ∼ D^0.64 and t ∼ D^0.68 for aluminum and magnesium powders, respectively. The results were compared to previous reports and possible reasons for discrepancies between the present and earlier results were discussed.     

Effects of dietary vitamin e supplementation and packaging on the quality of minced beef

Friesian cattle, aged 26-27 months, were fed a diet supplemented with 2000IU α-tocopheryl acetate/kg feed/day and another group was fed a basal diet (20IU/kg feed/day) for approximately 50 days prior to slaughter. Following frozen storage (-20°C for 8 weeks) semimembranosus muscles from basal and α-tocopheryl acetate supplemented cattle were minced and vacuum packaged, aerobically packaged or packaged under modified atmospheres (MAP) (30% O(2): 70% CO(2); 70% O(2): 30% CO(2); 80% O(2): 20% CO(2)). Samples were held under refrigerated (4°C) display (fluorescent lighting, 616 lux) for eight days. Vacuum-packaged samples were held under similar conditions but in complete darkness and allowed to bloom for a minimum of 4hr prior to taking colour readings. TBARS values and Hunter a values in minced beef were measured every two days. α-Tocopherol concentrations were significantly (p<0·05) higher in minced meat samples from the supplemented group than in the basal group. Significant (p<0·05) reductions in α-tocopherol concentrations in supplemented meat samples were observed with increased concentrations of oxygen in different packaging systems after eight days of refrigerated storage. TBARS values were reduced over the whole retail display period for all packaging systems when α-tocopheryl acetate supplemented beef was used. TBARS values increased as oxygen levels increased in MAP. Hunter a values showed that vitamin E supplementation in combination with vacuum packaging and MAP improved the colour stability of meat during the first 4 days of storage, however, the failure of MAP to extend meat colour for longer periods of time was probably the result of prior storage at -20°C for 8 weeks.     

Breeding birds and anurans of dynamic coastal wetlands in Green Bay,Lake Michigan

Breeding birds and anurans (frogs and toads) in coastal wetlands of Green Bay, Lake Michigan vary dynamically with changing water levels, habitat type, and geography. We describe species assemblages over a seven-year period (2011–2017) beginning with historic low water levels followed by an increase in average lake level of 0.85?m. In general, species richness and abundance of marsh-obligate species responded positively to increasing water levels, although several species of shallow wetlands (sandhill crane, sedge wren, swamp sparrow, and American toad) showed the opposite trend. Anuran assemblages were more diverse in the middle and upper bay, coinciding with a well-established nutrient gradient from the hypereutrophic lower bay to more oligotrophic waters of the upper bay. Three marsh-obligate bird species (black tern, sandhill crane, and sedge wren) were significantly more abundant in the middle or upper bay while sora, American coot, and common gallinule were more abundant in the eutrophic lower bay. Our findings have several important implications for conservation. Inland wetlands near the coast (including diked wetlands) might play a key ecological role by providing refugia for some species during low water years. However, the importance of shallow coastal wetlands and nearshore gradients of wetland habitat might be overlooked during low water years; when high water returns, these areas can become extremely productive and species-rich.     

Localization and temporal regulation of tissue inhibitor of metalloproteinases-4 in mouse ovary

Tissue inhibitors of metalloproteinases (TIMPs) are potential regulators of tissue remodeling in the ovary. The aim of the present study was to examine the localization and temporal regulation of TIMP-4 protein in the mouse ovary. An induced superovulation model (eCG/hCG) was employed in immature mice to evaluate TIMP-4 protein expression profiles in ovaries collected during the follicular phase, the pre ovulatory period, and the luteal lifespan. Immunofluorescence results indicated that TIMP-4 protein was localized to theca of both antral and preovulatory follicles and adjacent ovarian stroma. After the initiation of luteinization with hCG, TIMP-4 was observed within the luteinizing granulosa cells and persisted throughout the lifespan of the corpus luteum. In the cycling ovary, TIMP-4 signaling localized to corpus luteum from previous estrous cycles, the theca of preovulatory follicles, and appeared to be lower in newly forming corpus luteum. Western analysis further showed that the levels of TIMP-4 increased significantly during the luteinization process of granulosa cells, but no significant change was found among all corpus luteum stages. A putative regulatory mechanism of TIMP-4 expression was identified utilizing an in vitro model. Treatment of cultured granulosa cells with hCG significantly augmented TIMP-4 protein expression levels. Together our data indicate that the luteinization process of granulosa cells is associated with up-regulation of TIMP-4 and that TIMP-4 might play an essential role in maintenance of the luteal function during the whole lifespan of corpus luteum.     

Consequences of marketing exceptions in the Master Settlement Agreement: exposure of youth to adult-only tobacco promotions.

The Master Settlement Agreement between a consortium of tobacco companies and 46 states contains many restrictions on tobacco sales and advertising that were designed to reduce youth exposure to tobacco promotions. Most of the restrictions include an exception for "adult-only" facilities. The present study investigated the extent to which youth are being exposed to marketing that is presumably limited to adults. Using data from a statewide random-digit-dialed survey of 3,863 Massachusetts youth aged 12-17 years, we found that about half of all youth in this age group reported seeing cigarettes advertised at events, concerts, bars, or clubs in the past 12 months, and that about 5% of youth in this age group reported being present at a venue where free samples of cigarettes were being distributed. Youth exposed to this marketing were those most at risk for progression to established smoking. To our knowledge, this is the first study to estimate youth exposure to advertisements designed for adult-only venues. In light of the large body of evidence that exposure to tobacco advertising and promotion increases tobacco use among youth, our findings demonstrate the need to close the "adult-only" loophole.     

Microscopically focused synchrotron X-ray investigation of selenium speciation in soils developing on reclaimed mine lands

Chemical speciation determines Se solubility and therefore its bioavailability and potential for transport in the environment. In this study we investigated the speciation of Se in soil developed on reclaimed mine sites in the U.S. Western Phosphate Resource Area (WPRA) using micro-X-ray absorption near-edge structure (micro-XANES) spectroscopy and micro-X-ray fluorescence (micro-XRF) mapping. Selenium was nonuniformly distributed in the soils and positively correlated with Fe, Mn, Cu, Zn, and Ni. Sixteen points of interest (POI) from three soil samples were analyzed with micro-XANES spectroscopy. The XANES data indicated that Se is present in the soils in at least three oxidation states, Se(-II, 0), Se(IV), and Se(VI). Selenides or elemental Se dominated 7 of the 16 POI. Selenate was the dominant species at only one of the POI. The remaining eight POI were composed of both Se(IV) and Se(VI), with minor Se(-II, 0) contributions. The results of this research suggest that the reduced Se species in the soil parent material are oxidizing to Se(VI), one of the more mobile species of Se in the environment. This information can be used to better predict and manage Se availability in soils.     

The effects of dietary α-tocopheryl acetate supplementation and modified atmosphere packaging (MAP) on the quality of lamb patties

Contributions to water retention capacity (% WRC) and texture changes were determined for pork by-products (lung lobes, kidneys), chicken viscera (head, feet and viscera) and mechanically separated chicken (MSC) as affected by pH and various salts in a high-moisture model system. The % WRC for meat by-products and MSC was increased by increased pH (4.5-6.8). Pork lungs and MSC had the highest % WRC (p<0.05) among the meat by-products. Meat by-product % WRC was not signifcantly (p>0.05) affected by salt (2%), phosphate (0.3%) or NaOH (0.075%). Chicken viscera had the lowest (p<0.05) mean texture measurements among the meat by-products and MSC. Strong negative correlations (p<0.05) were obtained for texture with total collagen, soluble collagen and high ionic strength soluble (HIS) proteins. These results should be considered for product quality changes when these by-products are used in formulation of high moisture pet food products.     

母乳中的低聚半乳糖研究和应用的最新进展

本详述了低聚半乳糖的研究和应用的最新进展,并简述了低聚半乳糖的特性。