In this study, decoloration of Direct Blue 71 (DB71) and Direct Red 23 (DR23) has been discussed by using Multiwalled Carbon Nanotubes (MWCNTs) and Hydrogen peroxide under UV radiation. The purpose of this study is removal of organic compounds by using carbon nanotubes that are effective adsorbents for different types of pollutants, due to their porous nature and large surface area. It also causes catalytic decomposition of hydrogen peroxide. Adsorption rate was investigated under various parameters (initial dye concentration, salt, temperature and pH). The main objective of this study is to appraise the synergic effect between H2O2 and MWCNTs under UV radiation. The dye adsorption results of spectrophotometer, showed that by decreasing the dye concentration from 0.2 g/l to 0.05 g/l with the optimal value of MWCNTs 0.2 g/l and hydrogen peroxide 2 g/l at pH=4 and 6 cm distance from the UV lamp, the dye removal increased. 相似文献
In this study, central composite design (CCD) based on response surface methodology (RSM) was employed to optimize parameters of melt-spinning process of poly(ethylene terephthalate) partially oriented multifilament yarn (POMFY). On the basis of a four-variable CCD, RSM was used to determine the effects of spinning temperature, spinning pressure, take-up velocity and quenching air velocity on the levels of the elongation of POMFY as the response. The POMFY samples were also characterized by scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) analysis. By applying a quadratic regression analysis, an equation indicating the effect of each variables on the response was developed. The predicted values of the parameters showed excellent agreement with the experimental values (R2=0.9565, Adjusted-R2=0.916). Moreover, the results confirmed that the CCD mathematical model was a suitable method to optimize the melt-spinning parameters of POMFY in an industrial scale. 相似文献
ABSTRACTOn the basis of greenhouse bioassays, the sensitivities of root and shoot biomass of barley (Hordeum vulgare L.), corn (Zea mays L.), oilseed rape (Brassica napus L.) and sugar beet (Beta vulgaris L.) to soil-incorporated sulfosulfuron and tribenuron methyl were assessed. Shoot and root biomass production was measured 30 days after emergence. Plant responses, including roots and shoots dry weight per pot, were described by a three parameter log-logistic regression model as a function of sulfosulfuron or tribenuron methyl doses and the relative sensitivities were calculated at the various ED-levels with their associated 95% confidence intervals. The most precise ED-levels were that at ED50 and sensitivity rank was oilseed rape, sugar beet, corn and barley, whatever the chosen response level and herbicide. We calculated relative sensitivities at ED10, ED50 and ED90 for the species of barley, the most tolerant crop, as reference. Comparison of relative sensitivity of crops to both herbicides showed that the sensitivity of these crops was much larger for tribenuron methyl than for sulfosulfuron. Oilseed rape was the most sensitive species (ED50?=?0.202 and 0.179?µg?kg?1 soil for root dry weight (RDW) response to sulfosulfuron and tribenuron methyl, respectively) while barley was the most tolerant one (ED50?=?1.008 and 3.68?µg?kg?1soil for RDW response to sulfosulfuron and tribenuron methyl, respectively). Sugar beet and corn had intermediate sensitivity. Also, we demonstrated how important it is to show the confidence intervals of relative sensitivities. In several instances the relative sensitivities, even numerically large, were not significantly different from 1.00. We demonstrate that classifying biotypes as resistant to a herbicide requires the threshold of resistance/susceptible (R/S) of 4.00 only be accepted if confidence intervals do not cover 1.00. 相似文献
Yellow mosaic disease (YMD) is the major constraint of mungbean for realizing high productivity worldwide. Moreover, management of disease using YMD‐resistant genotypes is the simplest approach. Therefore, based on a preliminary screening of 220 genotypes during the year 2010 and 2011 at 17 locations, a set of 25 genotypes was further selected to evaluate at six locations over 2 years for identification of more stable resistant genotypes. The genotype and genotype × environment (GGE) analysis indicated that the genotypes and environment effects were significant (P < 0.001) for YMD incidence. Interestingly, the GGE biplot analysis successfully accounted for 74.71 per cent of the total variation with three genotypes (ML 818, ML 1349 and IPM 02‐14) showing high degree of resistance and stability over the locations. Notably, a strong positive association was observed between disease reaction and temperature, relative humidity and rainfall. As crop is grown in diverse growing environments, aforementioned genotypes can be used as stable/durable sources for future breeding programme to develop YMD‐resistant cultivars. 相似文献
A 12-yr. (2000–2011) study was conducted in Alberta, Canada to compare the energy use efficiency (EUE) of conventional (CONV) and conservation (CONS) potato (Solanum tuberosum L.) management practices. Potato was grown in 3- to 6-yr. rotations which included dry bean (Phaseolus vulgaris L.), sugar beet (Beta vulgaris L.), soft wheat (Triticum aestivum L.), oat (Avena sativa L.), and timothy (Phleum pratense L.). CONS included compost application, reduced tillage, cover crops, and solid-seeded bean. Findings suggested that potato in 5-yr. CONS produced the highest EUE compared to the other CONS or CONV rotations. CONS can be used as a means of reducing the reliance on non-renewable energy inputs and improving overall EUE of potato production when less than 21% of the N content of compost applied was counted toward energy input use of potato production. At more than 21%, potato in the 4-yr. CONV became more favorable compared to potato in other rotations. 相似文献
Fitness in tall fescue could be determined as the relative seed production by overcoming self-incompatibility barriers. This study was an attempt to investigate the effects of plant genotype and symbiotic fungal endophyte on seed production and associated traits in tall fescue. Fifteen clones of tall fescue free from endophyte and two clones with both endophyte-infected (E+) and non-infected (E?) counterparts were evaluated under two pollination systems of natural open-pollination and obligate self-pollination. Although seed yield was depressed by self-pollination in all E? genotypes, some genotypes exhibited reasonable selfing ratio. However, endophyte infection was much more effective to increase selfing ratio and seed yield through self-pollination particularly in the genotype 75B. Endophyte infection almost removed self-incompatibilty in the host plants and on average resulted in 3.0 times more number of seeds per self-pollinated seedheads than the non-counterpart E? tall fescue genotypes. Although it may need more elaborated studies, incorporating Epichloë fungal endophyte in plant genotypes not only may make the inbreeding in tall fescue possible but also may improve forage yield and seed production, simultaneously. 相似文献
This study was conducted to evaluate drought tolerance and persistence in a germplasm of smooth bromegrass and association of forage productivity with different traits. Thirty‐six genotypes of smooth bromegrass were clonally propagated and evaluated under two soil moisture environments for three years (2013–2015). High genotypic variation was observed among genotypes for all the measured traits. Drought stress decreased mean values for traits related to productivity. Also, the long‐term stress for three years reduced the persistence of plants. Results indicated that indirect selection based on components of forage yield, which had high heritability and high correlation with yield, would be more effective to improve drought tolerance in this germplasm. The results of principal component analysis showed that there was a negative relationship between phenological traits with the persistence‐related traits and yield production. This suggests that selection for earliness may indirectly promote persistent genotypes. The results showed that some Hungarian genotypes are valuable gene sources for persistence. The most persistent genotypes from both groups (Iranian and foreign) were identified using the biplot method. These genotypes may be useful for the development of populations for future studies. 相似文献
Choosing the right algae with the relevant properties and optimal harvest time for specific culture conditions and products is essential. As such, biomass, biochemical composition and fatty acid (FA) profile at different growth stages of locally isolated strains, suitable for aquaculture, Chlorella salina and Isochrysis maritima, were determined. Biomass and moisture content of both species were affected by the growth phase. A particular accumulation trend of proximate biochemical compounds was observed in these two strains. Protein content decreased whereby, as culture aged, more carbohydrate and lipid accumulated in C. salina and I. maritima, respectively. Variations in FA profile were exhibited in C. salina where PUFA was the highest, followed by SFA and MUFA throughout the growth phases. I. maritima had the highest SFA content, followed by PUFA and MUFA during the exponential phase. The essential PUFAs in C. salina were linoleic acid (LA) and α-linolenic acid (ALA) with a low occurrence of γ-linolenic acid (GLA; 0.49–0.78%) and docosahexaenoic acid (DHA; 0.21–0.45%). I. maritima recorded relatively high ALA (4.73–6.71%), GLA (5.05–7.80%) and DHA (5.15–7.02%) with minor presence of arachidonic acid (ARA; 0.45–0.59%) and eicosapentaenoic acid (EPA; 0.43–0.58%). Both C. salina and I. maritima are suitable for aquaculture feeds, but I. maritima was more superior by having EPA and higher DHA in their cells. Harvesting regime at a specific phase must be taken into account to achieve maximum yields of a target compound; thus, for feeding purpose, harvesting both strains at stationary phase is recommended as better PUFA compositions were obtained.
Recirculating aquaculture system (RAS) is a unique approach that offers total control to culture a wide variety of aquatic species. As capital investment is higher for setting up RAS, it is necessary to conduct an economic feasibility analysis based on real data. A structured questionnaire was used to collect all economic and technical data on two catfish species, viz., Pabda (Ompok pabda) and Shing (Heteropneustes fossilis), cultured in an RAS farm. The ultimate objective was to estimate net cash flow, net present value (NPV), profitability index (PI), payback period, discounted payback period, internal rate of return (IRR), and sensitivity analysis to find out the best profitability indicators. The analysis revealed that the IRR were 4% and 16% for Pabda and Shing production, respectively. However, for Pabda and Shing productions, the payback periods were 15 years and 4 months and 6 years and 2 months, respectively. The NPV value was positive for Shing production and negative for Pabda. On the other hand, the PI was lower than one for Pabda production and higher than one for Shing production. Therefore, the results showed that the Shing production in the RAS facility could be economically feasible; however, Pabda production may not be viable in RAS due to lower production and longer culture period. This study may suggest that by increasing the production capacity of the farm and market price of the product through the proper supply chain and by decreasing the initial investment, cost of fingerlings and feed, profitability can be achieved in RAS in Bangladesh.
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