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31.
Polypropylene fabrics were coated with copper particles using electroless plating, screen printing and wire arc spray coating techniques. Surface morphology of the fabrics was studied using optical and scanning electron microscopes (SEM). Furthermore, tensile strength, electrical conductivity, thermal conductivity, air permeability, water contact angle and fog collection efficiency of the coated fabrics were measured and the obtained results were analyzed. SEM micrographs showed that a very thin and uniform layer of copper deposited on the surface of the electroless plated polypropylene fibers. In the printed or spray coated fabrics the copper particles filled the spaces between yarns and fibers. The polypropylene electroless copper plated fabrics showed higher tensile strength, electrical conductivity, air permeability and thermal conductivity when compared with the fabrics coated with copper screen printed and copper spray coated fabrics. Finally, the obtained results showed that copper electroless plating could increase the fog collection efficiency of polypropylene fabrics considerably. As a conclusion, the surface modified copper electroless polypropylene fabrics are good candidates for fog collection in appropriate regions which need further investigations.  相似文献   
32.
This study investigated the effects of fish meal replacement by Spirulina platensis meal on growth, survival, body biochemical composition, and reproductive performance of Trichopodus trichopterus until the first spawning for 16 weeks. The fish fed dietary algal meal at levels of 2.5, 5, 10, and 20 % against those received fish meal only as control. The results showed that indicators such as belly diameter, feed intake, feed conversion ratio (FCR), and viscerosomatic index were significantly different between treatments with 5 and 10 % algal replacements (P < 0.05). The growth factors including final weight, weight gain, total length, fork length, and body height of fish did not show significant differences (P > 0.05) between the treatments. Feed intake increased up to 10 % replacement level and then decreased, though the best FCR values (0.77–0.79) were obtained with 2.5 and 5 % substitutions. The body lipid content showed a statistically marked decrease (P < 0.05) as a result of the algal replacements, but the amounts of protein and moisture were not significantly (P > 0.05) different between treatments. All fish fed S. platensis meal had greater gonadosomatic indices (19.4–21.85 %) than that of the control in spite of insignificant differences (P > 0.05) in their ovary weights (2.07–2.21 g). Absolute fecundity ranged between 7300 and 12,700 eggs/female with the highest amount in fish fed with replaced S. platensis levels of 2.5–10 %. The second-order polynomial regression analysis between absolute fecundity and substitution levels of algal meal was y = ?0.5319x 2 + 106.87x + 7812.9 (R 2 = 0.9642), and the optimal substitution level was determined to be 8.13 % for maximum absolute fecundity. Hatching percentages in the control and 20 % replacement were much lower (P < 0.05) than those in the other treatments (78–86 %). Given the relative enhancement of growth parameters and significant improvement in reproductive performance of broodstock three-spot gourami, 8.1–9.6 % S. platensis meal instead of fish meal is recommended in the diets.  相似文献   
33.
Polyamines [i.e. spermine (Spm), spermidine (Spd) and putrescine (Put)] antagonistic effects on stress imposed by 2.0 mM lead (Pb2+) on growth, yield and its components and changes in the osmoprotectant and endogenous Pb2+ concentrations, the contents of some nutrients and tissue health in wheat plants were evaluated. Under the three applied polyamine (PAs) applications, the efficiency of wheat plants to tolerate Pb2+ stress in terms of growth and yield characteristics was noticed to varying degrees. The enhancements in osmoprotectant concentrations and plant health [in terms of relative water content (RWC) and membrane stability index (MSI)], and reductions in electrolyte leakage (EL) and plant Pb2+ concentration were correlated with the reasonable growth of Pb2+-stressed plants and their grain yield. Results point out that, better growth and yield characteristics, MSI, RWC, leaf photosynthetic pigment and osmoprotectant concentrations, and nutrient contents were obtained with seed soaking in 0.25 mM Spm, 0.50 mM Spd or 1.0 mM Put than those generated with seed soaking in water under 2.0 mM Pb2+ stress. In contrast, EL and the concentration of endogenous Pb2+ were significantly reduced. However, the Pb2+-free control positively exceeded the all stressed treatments. Among all tested PAs, 1.0 mM Put showed the best results and thus is recommended, as seed soaking, for wheat to grow well under Pb2+ stress.  相似文献   
34.
A soilless pot experiment was conducted to investigate the effects of different growing substrates on vegetative and reproductive growth of bell pepper. The growing substrates consisted of: rice hull (100%), perlite (100%), coarse saw dust (100%), rice hull (75%)+zeolite (25%), perlite (75%)+zeolite (25%), saw dust (75%)+zeolite (25%), rice hull (50%)+perlite (50%), saw dust (50%)+perlite (50%), and rice hull (50%)+saw dust (50%) (by volume). Results showed that for all measured vegetative traits the highest and lowest amount was related to the plants grown in the perlite+zeolite and pure rice hull or saw dust, respectively. Results also showed that using perlite+zeolite as the media produced the highest fruit number and yield, while plant grown in the saw dust+zeolite produced the lowest fruit number. According to the results, adding zeolite and perlite to rice hull or saw dust in most cases, significantly increased the pepper yield compared with their pure treatments.  相似文献   
35.
Field experiments were conducted in Iran in order to determine the interactions between the tillage system and crop rotation on weed seedling populations and crop yields from 2002 to 2005. No tillage, shallow tillage and deep tillage were the main plots and three crop sequences comprising continuous wheat (W‐W), wheat–canola–wheat–canola (C‐W) and wheat–safflower–wheat–safflower (S‐W) were the subplots. Bromus japonicus, Carthumus lanatus, Polygonum aviculare, Lolium temulentum and Avena ludoviciana were found to be the dominant species. The initial weed population in 2002 was estimated at 65 seedlings per m2 and B. japonicus (~35 seedlings per m2) was the most abundant species, followed by A. ludoviciana and L. temulentum. The dominant weed species mostly did not favor the combination of S‐W and C‐W with any tillage type. For the B. japonicus population, S‐W in combination with moldboard plowing indicated the lowest seedling population. In conclusion, the crop sequence in combination with tillage would help to control troublesome weed species. Safflower and canola were determined to be effective in reducing the grass weeds. The inclusion of these crops in rotation also increased the total revenue of the cropping systems because of the higher sale price of canola and safflower.  相似文献   
36.
Aquaculture International - In the present study, the white shrimp, Litopenaeus vannamei, was supplemented with the probiotic Bacillus subtilis IS02 in order to improve the larval survival rate....  相似文献   
37.
2,4-Dichlorophenoxyacetic acid (2,4D) is one of the widely used herbicide of the phenoxy family with possible startling number of adverse effects on species other than the weeds which is designed to kill. The effects of 2,4D were investigated in jerboa (Jaculus orientalis), a wild animal of subdesert highlands. The jerboas have been daily treated intraperitonally with 2,4D 3 mg/kg body weight for 4 weeks. Plasmatic markers, and antioxidants defences systems were assessed and histological alterations were evaluated. The in vivo and in vitro effects of 2,4D on the mitochondrial d-3-hydroxybutyrate dehydrogenase (BDH) were also determined. Our results showed a strong decrease of triglycerides level and HDL cholesterol and an increase in GOT level and LDL cholesterol. The microscopic evaluation showed that 2,4D induced necrosis of seminiferous tubules cells in testis, hyperplasia of hepatocytes in liver and presence of multinucleated giant cells in brain. The results show also an inhibitory effect on BDH in terms of activity and kinetic parameters. All of these results show that 2,4D induces toxicity which affects energy metabolism, morphological perturbation and oxidative stress.  相似文献   
38.
Allelopathy is a procedure in which secondary metabolites are produced by plants. Some plants may beneficially or antagonistically affect other plants through allelochemical compounds which may be released directly or indirectly from live or dead parts and cause allelopathic and phytotoxic effects. The aim of the present study was to investigate the allelopathic possibility of ajowan (Carum copticum) extracts in different concentrations on morphological indices (germination and growth) of wheat (Triticum sativum), barley (Hurdeum vulgare), corn (Zea maize S.C 704), and safflower (Carthamus tinctorius L.) seedlings as proceeding crops and to develop a comprehensive formula for measuring the negative and positive effects of allelochemicals on growth indices such as shoot and root length, as well as the germination percentage on donor plants. It was demonstrated that increasing concentrations of ajowan extracts significantly decreased the Allelopathic Index, percent of germination, and other growth related indices of all seedlings. Based on the proposed Allelopathic Index of experimental plants, it was revealed that ajowan has posed a higher risk to corn and barley especially at the early stages of the growing cycle, while safflower and wheat indicated more tolerance to growth inhibition effects of ajowan in rotational sequence.  相似文献   
39.
Journal of Crop Science and Biotechnology - Salinity is one of the most brutal abiotic stressors, commencing a great stumbling block in the way of attaining food security in Bangladesh. Cultivation...  相似文献   
40.
This study was conducted to evaluate the feeding value of whole date palm (WDP) with and without enzyme supplementation on aged laying hen’s performance. Apparent metabolizable energy value of WDP was determined by the total collection method using ten adult leghorn cockerels. WDP was substituted with a corn-soybean meal basal diet at 40% level, and then the metabolizable energy of this experimental diet and basal diet was determined. After that, a total number of 256 Bovanz 95-week-old hens were randomly allocated into eight groups consisting of four replicates of eight birds each, based on a 4 × 2 factorial arrangement of the treatments. Eight iso-caloric and iso-nitrogenous experimental diets including one corn-soybean meal-based control diet and two, three, and four corn-soybean meal-based diets included 70, 140, and 210 g/kg ground WDP, respectively. Each of the diets supplemented with two levels of an enzyme (0.0 and 0.07 g/kg Natozim Plus). There was no significant difference in feed intake, feed conversion ratio, egg production, egg mass, eggshell thickness, and Haugh unit among the treatments (P > 0.05). However, yolk color score significantly decreased as dietary WDP level increased. The serum biochemical metabolites were not significantly affected by WDP and enzyme supplementation (P > 0.05). There were no significant differences in the relative weight of different organs except for abdominal fat. Our findings show that using WDP up to 21% of the diet was more economic and had no adverse effect on productive performance and serum metabolites of laying hens. However, WDP had an adverse effect on yolk color which can be ameliorated by carotenoid supplementation.  相似文献   
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