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Alex T. Hung Brian J. Leury Matthew A. Sabin Fahri Fahri Kristy DiGiacomo Tu-Fa Lien Frank R. Dunshea 《动物营养(英文)》2021,7(1):198
Two studies were conducted to evaluate the effect of nano chromium picolinate (nCrPic) during heat stress (HS) in sheep. In the initial study, 36 Merino × Poll cross-bred sheep were individually penned and allocated to 3 dietary treatments (0, 400 and 800 μg/kg nCrPic) for 8 wk. Body composition was determined at the beginning and end of the experiment using dual energy X-ray absorptiometry. The sheep remained in their dietary groups but were then placed in metabolic cages and randomly allocated within the dietary group to differing ambient temperature regimes, i.e., thermo-neutral (TN) (n = 18) and HS (n = 18), for 3 wk. Dietary nCrPic had no effect on growth performance and body composition during the initial study conducted under TN conditions. Heat stress decreased average daily feed intake (ADFI) (P = 0.002) whereas sheep under HS had reduced average daily gain (ADG) and indeed lost weight (P < 0.001). Dietary nCrPic increased both ADFI (P = 0.041) and ADG (P = 0.049) under both TH and HS conditions such that the performance of sheep receiving supplemental nCrPic and exposed to HS was similar to that of control sheep maintained under TN conditions. Heat stress increased rectal temperature (P < 0.001) and respiration rate (P < 0.001), particularly during the hottest parts of the day as indicated by interactions (P < 0.001) between time of day and thermal treatment. Rectal temperature was lower in sheep fed nCrPic (P = 0.050), particularly under peak HS conditions during the afternoon as indicated by the interactions between dietary nCrPic and time of day (P < 0.001) and dietary nCrPic, thermal treatment and time of day (P = 0.010). Similarly, respiration rate was lower in sheep fed nCrPic under peak HS conditions during the afternoon as indicated by the interactions between dietary nCrPic and thermal treatment (P < 0.001) and dietary nCrPic and time of day (P = 0.030). In conclusion, dietary nCrPic can partially ameliorate the negative effects of HS as indicated by the maintenance of ADFI and decreased physiological responses, such as elevations in rectal temperature and respiration rate. 相似文献
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Layered fabric systems with electrospun polyurethane fiber web layered on spunbonded nonwoven were developed to examine the
feasibility of developing protective textile materials as barriers to liquid penetration using electrospinning. Barrier performance
was evaluated for layered fabric systems, using pesticide mixtures that represent a range of surface tension and viscosity.
Air permeability and water vapor transmission were assessed as indications of thermal comfort performance. Protection performance
and air/moisture vapor transport properties were compared for layered fabric systems and existing materials for personal protective
equipment (PPE). Layered fabric systems with electrospun nanofiber web showed barrier performance in the range between microporous
materials and nonwovens used for protective clothing. Layered fabric structures with the web area density of 1.0 and 2.0 g/m2 exhibited air permeability higher than most PPE materials currently in use; moisture vapor transport was in a range comparable
to nonwovens and typical woven work clothing fabrics. Comparisons of layered fabric systems and currently available PPE materials
indicate that barrier/transport properties that may not be attainable with existing PPE materials could be achieved from layered
fabric systems with electrospun nanofibrous web. 相似文献
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In this paper, we report the development, characterization and bioefficacy evaluation of fipronil nanoformulations against brown plant hopper (BPH); Nilaparvata lugens in rice. Nanoformulations were characterized for nanosizing and stability under variable conditions. Bioefficacy of nanoformulations were evaluated under field condition at farms of Indian Agricultural Research Institute, New Delhi during Kharif 2015. At milking stage BPH populations were above economic threshold level; followed by foliar application of fipronil nanoformulations at four doses (viz., 30, 45, 60 and 90 g a.i./ha) along with commercial formulation of fipronil. The mean mortality clearly indicated that all the insecticidal treatments were significantly superior over untreated control where, highest mortalities were observed in nanodispersions followed by monolithic dispersion and commercial formulation of fipronil. Treated plots 7 days after application @ 60 g a.i./ha has shown 93.47%, 86.89% and 80.47% reduction BPH population in nanodispersion, encapsulated monolithic dispersion and commercial formulation treated plots respectively. In comparison to commercial formulation @ 60 g a.i./ha yield has increased by 0.56 t ha?1 (28.76%) and 0.26 t ha?1 (14.04%) in nanodispersion and monolithic dispersion. 相似文献
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We studied the effects of nanoparticles of organo-silane(NOS) compounds in the size range of20–80 nm on physical and mechanical properties in medium density fiberboard,and used NOS at four consumption levels of 0,50,100,and 150 g kg-1dry wood fibers.Density of all treatments was kept constant at 0.67 g cm-3.The water-repellent property of organo-silane significantly reduced water absorption(WA) and thickness swelling but mechanical properties declined due to the reduced proportion of wood-fiber as organo-silane was added to the matrix:the compression ratio of MDF panels and the integrity among wood-fibers both declined,resulting in reduced mechanical properties.We recommend use of 50 g of NOS/kg wood-fiber to improve WA and thickness swelling while retaining acceptable mechanical properties. 相似文献
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ABSTRACTTo examine the effect of nanoparticulate phosphate rock (NPR) as both a liming agent and phosphorus source in a tropical acid soil. The study examined five rates of NPR (0, 250, 500, 1000, or 2000 kg ha?1), which supplies 30, 60, 120 or 240 kg P ha?1, in a randomized complete pot experiment design with 3 replications. The pots of soil were incubated in a climate-controlled greenhouse for 21 days and then spinach was grown for 49 days. Soil parameters (pH, available P and exchangeable acidity), spinach parameters (leaf area, root hair surface area, root length and dry matter yield) and the effectiveness of NPR dissolution were estimated. The soil and plant parameters and the effective NPR dissolution all increased to the same degree at 1000 and 2000 kg NPR ha?1. Therefore, the use of 1000 kg ha?1 was most economically justified. Although, NPR has been appeared as an effective liming agent and phosphorus source in tropical acid soil. However, a regular application of NPR and further research for economic comparison between NPR and both of lime and superphosphate, as well as the original PR, will be needed. 相似文献
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Seungsin Lee 《Fibers and Polymers》2009,10(3):295-301
This research investigates applying zinc oxide nanoparticles to polypropylene nonwoven fabrics via electrospinning for the
development of UV-protective materials. Layered fabric systems with electrospun zinc oxide nanocomposite fiber webs were developed
at various concentrations of zinc oxide in a range of web area densities. The effects of zinc oxide concentration and web
area density on the UV-protective properties of layered fabric systems were examined. Air and moisture vapor transport properties
of layered fabric systems were assessed to examine the effect of electrospun web layers on thermal comfort properties of the
material. A very thin layer of electrospun zinc oxide nanocomposite fibers significantly increased the UV blocking for both
UV-A and UV-B ranges, and exhibited an ultraviolet protection factor (UPF) of greater than 40, indicating excellent UV protection.
UV-protective properties of layered fabric systems increased with increasing zinc oxide concentrations of the nanocomposite
fiber web. Increasing the electrospun web area density of the zinc oxide nanocomposite fiber web also enhanced UV-protective
properties of layered fabric systems. Air and moisture vapor transport properties of layered fabric systems decreased as the
electrospun web area density increased for the range of web area densities examined. 相似文献