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11.
The prospects for rapid near-term development of a synfuel industry in the USA have decreased, due to depressed world oil prices, synfuel project cost overruns, and the lukewarm support of the Reagan administration. Nonetheless, socioeconomic and environmental impact analysis studies can provide valuable information for determining the regional welfare effects of proposed projects. The author discusses the results of a regional econometric analysis of the synfuel projects planned for Western Kentucky, which focuses on environmental impacts, and reveals the inevitable trade-offs that would accompany synfuel development. Some policy issues are briefly reviewed, especially that of efficient energy pricing.  相似文献   
12.
Two Likert-type scales for measuring parents' and caretakers' level of satisfaction with the food and nutrition services offered at childcare multi-centers in a peri-urban community in Caracas, were developed and validated. An intentional sample of 20 parents and caretakers were interviewed within the naturalistic-constructivist perspective, to capture their perceptions of distinct aspects of the food and nutrition components of the program. Categories emerged from the interviews that served to construct the items for two scales that measure level of satisfaction of parents and caretakers with the food and nutrition aspects of the program. To validate the scales, they were applied to 73 parents and 32 caretakers. Factor and multiple components analysis showed that overall, the scales explained 61% and 69% of the variation in level of satisfaction of parents and caretakers respectively. Confiability measured with Alpha Cronbach coefficient was 0.74 and 0.77 for parents' and caretakers' scales respectively. These results reveal scales that have content validity and good reliability. Besides, the scales detect specific aspects of the food and nutrition service that should be reinforced or modified, to make the Child-care Centers program more effective and efficient. External validation of the scales is recommended, since they provide an instrument capable of capturing useful information for monitoring and evaluating the Child-care Centers program nation-wide, from the perspective of program managers and parents of program users.  相似文献   
13.
Abstract

The basic premise of developing any information system is to increase efficiency and manage information in an improved manner. Based on the definitions above, an information system is “a group of devices or artificial objects serving a common purpose to communicate knowledge or intelligence.” Most information systems evolve from processes that either manipulate much information or rely on complex calculations. In other words, information systems are developed either to manage information or to manipulate it. Systems are meant to receive input, manipulate the input, and provide output.  相似文献   
14.
The Internet is full of unwanted traffic, from junk mail, to advertising and scams that pose as social media, to fake "clicks" on ads, to denial-of-service attacks against online services. Each type causes problems in one way or another, and network operators have to work hard to identify and eliminate unwanted traffic. This issue examines the overall problem, and presents a selection of research into mitigation.  相似文献   
15.
Amino acid changes S180A (S-->A at site 180), H197Y, Y277F, T285A, and A308S are known to shift the maximum wavelength of absorption (lambda max) of red and green visual pigments toward blue, essentially in an additive fashion. To test the generality of this "five-sites" rule, we have determined the partial amino acid sequences of red and green pigments from five mammalian orders (Artiodactyla, Carnivora, Lagomorpha, Perissodactyla, and Rodentia). The result suggests that cat (Felis catus), dog (Canis familiaris), and goat (Capra hircus) pigments all with AHYTA at the five critical sites have lambda max values of approximately 530 nm, whereas rat (Rattus norvegicus) pigment with AYYTS has a lambda max value of approximately 510 nm, which is accurately predicted by the five-sites rule. However, the observed lambda max values of the orthologous pigments of European rabbit (Oryctolagus cuniculus), white-tailed deer (Odocoileus virginianus), gray squirrel (Sciurus carolinensis), and guinea pig (Cavia procellus) are consistently more than 10 nm higher than the predicted values, suggesting the existence of additional molecular mechanisms for red and green color vision. The inferred amino acid sequences of ancestral organisms suggest that the extant mammalian red and green pigments appear to have evolved from a single ancestral green-red hybrid pigment by directed amino acid substitutions.  相似文献   
16.
Proteomics has long been thought to hold the promise of producing results of clinical utility which will influence patient treatment and outcomes. A recent Wellcome Trust/EBI meeting and retreat--“Perspectives in Clinical Proteomics”--brought together experts from a broad range of stakeholder groups with an interest in ensuring proteomics achieves this aim. This viewpoint presents views derived from these forums, proposing a pathway for the development of next-generation proteomic analyses in the clinical setting from selection of candidates through to their validation and ultimate demonstration of utility through health technology assessments. Although not meant to be all encompassing, important elements for proteomics researchers to consider are presented.  相似文献   
17.
Hurricanes and tropical storms are severe threats to coastal properties, settlements, and infrastructure. Airborne light detection and ranging (lidar) surveys conducted before and after storm events allow detailed analysis of coastal geomorphologic and sediment volumetric changes and have been proved very useful in the study of coastal changes. Traditionally, most studies use the pixel-based differencing method to quantify the spatial extent and magnitude of coastal changes based on sequential lidar surveys. This research presents a graph theory-based approach and associated software tools for representing and quantifying storm-induced damages to buildings, beaches and sand dunes, coastal vegetation canopy, and infrastructure. Generation of elevation difference grids, construction of local contour trees, and derivation of semantic properties are key components of the new algorithm for change object detection and extraction. An ontology and taxonomy are proposed to classify change objects into different types of coastal damages in terms of their semantic properties. This method has been successfully applied to assess damages of Hurricane Ike to the Bolivar Peninsula on the Texas Gulf Coast based on pre- and post-storm airborne lidar data and colour infrared aerial photographs.  相似文献   
18.
19.
Aromatic Hydrogenation Catalysis: A Review   总被引:14,自引:0,他引:14  
High aromatic content in diesel fuel has been recognized both to lower the fuel quality and to contribute significantly to the formation of undesired emissions in exhaust gases [1, 2]. Because of the health hazards associated with these emissions, environmental regulations governing the composition of diesel fuels are being tightened in both Europe and the United States, leading to limitations on aromatics [3, 4].  相似文献   
20.
Phase relations in the BaTiO3—TiO2 system were studied at temperatures above 1300°C in air. Quenching experiments were performed with high-purity reagents, and a new equilibrium phase diagram was constructed. Results include redetermination of the liquidus boundaries, the eutectic temperature, the melting or decomposition temperatures of the stable compounds in the system, the cubic—hexagonal transition in BaTiO3, and the solid solubility of TiO2 in BaTiO3.  相似文献   
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