288 research outputs found

    A multi-criteria performance study of an integrated demand/supply energy system for low and zero carbon technologies within domestic building design

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    When low carbon and renewable energy (RE) systems are adopted in a building, matching the outputs from RE systems (e.g. photovoltaic, solar collectors, small scale wind turbines and heat pumps) to demand has to be taken into account to fully realise the potential of the hybrid energy system. Considering the varying demand profiles due to different building design options (e.g. orientation, construction types etc), it is necessary to evaluate key technology elements in an integrated context and establish appropriate strategies for simultaneously meeting heating and electricity loads as well as matching demand and supply. This paper presents a new approach to evaluate the interactive effects of low carbon technologies and demand reduction measures in the early design stage of a new building. A case study of a sustainable domestic building project (PLUS 50), was implemented on the basis of the proposed design approach

    Effects of different levels of dietary crude protein on growth performance, blood profiles, diarrhea incidence, nutrient digestibility, and odor emission in weaning pigs

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    Objective This experiment was conducted to evaluate the effects of different levels of dietary crude protein (CP) on growth performance, blood profiles, diarrhea incidence, nutrient digestibility, and odor emission in weaning pigs. Methods A total of 240 weaning ([Yorkshire×Landrace]×Duroc) pigs (8.25±0.050 kg body weight [BW]) were assigned to six treatments based on sex and initial BW, with five replicates of eight pigs per pen in a randomized complete block design. Experimental diets with different crude protein levels for early and late weaning phases were as follows: i) CP16, corn-soybean-based diet containing 16%/15% CP; ii) CP17, corn-soybean-based diet containing 17%/16% CP; iii) CP18, corn-soybean-based diet containing 18%/17% CP; iv) CP19, corn-soybean-based diet containing 19%/18% CP; v) CP20, corn-soybean-based diet containing 20%/19% CP; and vi) CP21, corn-soybean-based diet containing 21%/20% CP. Results In the early weaning period, average daily feed intake increased when the dietary CP level decreased (linear, p<0.05). During the entire experimental period, average daily gain and the gain to feed ratio decreased when the dietary CP level increased (linear, p< 0.01). Additionally, a decrease in dietary CP level resulted in a linear increase in final BW (linear, p<0.05). In the early and late weaning periods, blood urea nitrogen (BUN) decreased when the dietary CP level decreased (linear, p<0.01). There were no significant differences in creatinine, glucose, total protein, triglyceride or insulin-like factor-1 levels over the experimental period. The concentrations of immunoglobulin A (IgA) and IgG were not significantly affected by dietary CP levels during the experimental period. In the early weaning period, fecal and urine N decreased when the dietary CP level decreased (linear, p<0.01). No differences in nutrient digestibility among the treatments during the early weaning period were found. Throughout the whole experimental period, when the dietary CP level decreased in the weaning pig diet, the diarrhea incidence decreased linearly (linear, p<0.01). Throughout the whole experimental period, when the dietary CP level decreased in the weaning pig diet, ammonia, amines and hydrogen sulfide decreased linearly (linear, p<0.01). Conclusion Reducing dietary CP could decrease diarrhea incidence, the concentration of BUN in serum and odor emission in manure. Furthermore, it could improve N excretion in feces and urine and growth performance in weaning pigs

    Effects of different levels of dietary crude protein on the physiological response, reproductive performance, blood profiles, milk composition and odor emission in gestating sows

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    Objective This study was conducted to evaluate the effects of crude protein (CP) levels on the physiological response, reproductive performance, blood profiles, milk composition and odor emission in gestating sows. Methods Seventy-two multiparous sows (Yorkshire×Landrace) of average body weight (BW), backfat thickness, and parity were assigned to one of six treatments with 10 or 11 sows per treatment in a completely randomized design. Experimental diets with different CP levels were as follows: i) CP11, corn–soybean-based diet containing 11% CP; ii) CP12, corn–soybean-based diet containing 12% CP; iii) CP13, corn–soybean-based diet containing 13% CP; iv) CP14, corn–soybean-based diet containing 14% CP; v) CP15, corn–soybean-based diet containing 15% CP; and vi) CP16: corn–soybean-based diet containing 16% CP. Results There was no significant difference in the performance of sow or piglet growth when sows were fed different dietary protein levels. Milk fat (linear, p = 0.05) and total solids (linear, p = 0.04) decreased as dietary CP levels increased. Increasing dietary CP levels in the gestation diet caused a significant increase in creatinine at days 35 and 110 of gestation (linear, p = 0.01; linear, p = 0.01). The total protein in sows also increased as dietary CP levels increased during the gestation period and 24 hours postpartum (linear, p = 0.01; linear, p = 0.01). During the whole experimental period, an increase in urea in sows was observed when sows were fed increasing levels of dietary CP (linear, p = 0.01), and increasing blood urea nitrogen (BUN) concentrations were observed as well. In the blood parameters of piglets, there were linear improvements in creatinine (linear, p = 0.01), total protein (linear, p = 0.01), urea (linear, p = 0.01), and BUN (linear, p = 0.01) with increasing levels of dietary CP as measured 24 hours postpartum. At two measurement points (days 35 and 110) of gestation, the odor gas concentration, including amine, ammonia, and hydrogen sulfide, increased linearly when sows fed diets with increasing levels of dietary CP (linear, p = 0.01). Moreover, as dietary CP levels increased to 16%, the odor gas concentration was increased with a quadratic response (quadratic, p = 0.01). Conclusion Reducing dietary CP levels from 16% to 11% in a gestating diet did not exert detrimental effects on sow body condition or piglet performance. Moreover, a low protein diet (11% CP) may improve dietary protein utilization and metabolism to reduce odor gas emissions in manure and urine in gestating sows

    Multi-authority attribute-based keyword search over encrypted cloud data

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    National Research Foundation (NRF) Singapore; AXA Research Fun

    A broadband X-ray study of the Rabbit pulsar wind nebula powered by PSR J1418-6058

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    We report on broadband X-ray properties of the Rabbit pulsar wind nebula (PWN) associated with the pulsar PSR J1418-6058 using archival Chandra and XMM-Newton data, and a new NuSTAR observation. NuSTAR data above 10 keV allowed us to detect the 110-ms spin period of the pulsar, characterize its hard X-ray pulse profile, and resolve hard X-ray emission from the PWN after removing contamination from the pulsar and other overlapping point sources. The extended PWN was detected up to ∼\sim20 keV and is well described by a power-law model with a photon index Γ≈\Gamma\approx2. The PWN shape does not vary significantly with energy, and its X-ray spectrum shows no clear evidence of softening away from the pulsar. We modeled the spatial profile of X-ray spectra and broadband spectral energy distribution in the radio to TeV band to infer the physical properties of the PWN. We found that a model with low magnetic field strength (B∼10B\sim 10 μ\muG) and efficient diffusion (D∼1027D\sim 10^{27} cm2^2 s−1^{-1}) fits the PWN data well. The extended hard X-ray and TeV emission, associated respectively with synchrotron radiation and inverse Compton scattering by relativistic electrons, suggests that particles are accelerated to very high energies (≳500\gtrsim500 TeV), indicating that the Rabbit PWN is a Galactic PeVatron candidate.Comment: 21 pages, 10 figures. ApJ accepte
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