The aim of this study was to investigate fatty acid profiles of different shrimp species caught from deep water and shallow water. The shrimp species investigated in the study were Aristeus antennatus, Aristeomorpha foliacea, Plesionica martia, Parapenaeus longirostris, and Plesionica edwardsi from deep water; and Metapenaeus monoceros, Penaeus semisulcatus, Penaeus kerathurus, and Penaeus japonicus from shallow water. Fatty acid composition of shrimps varied. The main fatty acids were C18:1n9, C16:0, C25:6n3, C22:5n3, and C18:0. Saturated, monounsaturated, and polyunsaturated fatty acid (PUFA) contents of P. longirostris, P. edwardsi, and M. monoceros were markedly different, respectively. The ratio of n6/n3 of the edible tissue of M. monoceros was found to be 0.795, whereas this value was 0.152 in A. foliacea. Among the species studied, the highest docosahexaenoic acid + eicosapentaenoic acid value was found for P. kerathurus. The levels of PUFAs of shallow water shrimps (ranging from 33.44 to 42.77%) were found to be higher than those of deep water shrimps (ranging from 29.68 to 33.95%). Marine animals in the upper water layers gain nutrition through phytoplankton which provides n-3 PUFA depending on solar energy. Shallow water shrimp species provide a satisfying amount of PUFA. 相似文献
An attempt has been made to set up a relationship between the removal efficiency and the dispersion characteristics of biological filters. For granular-media trickling filters, effluent concentrations have been calculated with the equation of complete mixing at low flow rates and by means of a dispersed plug-flow model for large hydraulic loadings. For coarse media, the mixed flow zone disappears and the substrate removal is obtained using the equation of dispersed plug flow. The effect of temperature and substrate concentration on the filter efficiency has been investigated using the model developed and the application of this theory to the practical problems has been thus demonstrated. 相似文献
A numerical model of biofilm reactors was tested using Monod typebiological kinetics in terms of the properties of feed solutionand dispersion. The model is based on computer techniques andthe numerical evaluation of the normalized biofilm mathematicalmodel. The effect of inlet parameters including concentration,flow rate, mass transfer coefficient and biofilm thickness wereinvestigated using the computer program developed. The numericalmodel was also applied to experimental data to demonstrate itsvalidity. In thin biofilms kinetic coefficients and otherparameters such as molecular diffusivity can be determinedbased upon experimental results. In thick biofilms, however, anadditional kinetic parameter or any other quantity related tomass transfer is a prerequisite in the evaluation ofexperimental data. 相似文献
A numerical model is presented to determine hydraulic and solids residence times and effluent concentrations from activated sludge reactors systems. Mass balance equations for biomass and substrate are numerically solved to determine the effects of different variables. Dimensionless quantities and computer techniques are used to express the results generally. Monod kinetics and reactors-in-series principles are applied to explain variations in axial dispersion andwastewater quality experienced in real systems. By means of the numerical approach, the variation of the ratio between the hydraulic residence time of a given reactor and that of an equivalent plug-flow tank with the same inlet and outlet conditions is investigated. Using the numerical results obtained, graphs are plotted for designing plug-flow activated sludge systems. Experimental data reported in literature is also evaluated to demonstrate the cases where the existing classical solution to the problem differs from the exact results. 相似文献
The effect of pyrolysis temperature on the nutritional quality of agricultural biochar is unclear, so better understanding of its properties and how it affects soil nutrient availability and plant growth is needed. Biochars obtained at different pyrolysis temperatures (250, 300, 350 and 400 °C) were characterized by thermogravimetric analyser and Fourier transform infrared spectroscopy. Biochars were applied at a rate of 10 g/kg to find out their effects on the mineral nutrition and growth of lettuce. The experimental results suggested that high biochar temperatures caused oxidation of the mineral elements, breaking of C–C and C–H bonds and removal of aliphatic and peptide groups from the pyrolysed materials. The total concentrations of phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), iron (Fe), zinc (Zn), copper (Cu), manganese (Mn) and boron (B) were increased by increasing pyrolysis temperatures, although water‐soluble concentrations of those elements were greatly reduced (with the exception of K and B). Compared to the control, dry weights of lettuce and maize crops were significantly increased by the biochar treatments obtained at 300 and 350 °C. Biochar treatments significantly increased the P and K concentrations of both plants compared to the control, while concentrations of Ca and Mg in lettuce plants were decreased. Iron, Mn and B concentration of the lettuce plants were reduced and Zn concentration of maize increased by the biochar treatments. It was concluded that in terms of an agricultural product, biochars produced at low temperature are better. 相似文献
Drought stress and zinc (Zn) deficiency are serious abiotic stress factors limiting crop production in Turkey, especially in Central Anatolia. In this study, the effects of Zn deficiency and drought stress on grain yield of 20 wheat cultivars (16 bread wheat, Triticum aestivum; four durum wheat, Triticum durum cultivars) were investigated over 2 years under rainfed and irrigated conditions in Central Anatolia where drought and Zn deficiency cause substantial yield reductions. Plants were treated with (+Zn: 23 kg Zn ha−1, as ZnSO4·7H2O) and without (−Zn) Zn under rainfed and irrigated conditions. Both Zn deficiency and rainfed treatments resulted in substantial decreases in grain yield. Significant differences were determined between both bread wheat and durum wheat cultivars in terms of drought stress tolerance. Considering drought sensitivity indices over 2 years, the bread wheat cultivars Yayla‐305, Gerek‐79, Dagdas‐94 and Bolal‐2973 were found to be more drought‐tolerant than the other cultivars under both −Zn and +Zn treatments. Especially the durum wheat cultivars Cakmak 79 and Selcuklu 97 showed much greater drought susceptibility under Zn deficiency, and irrigation alone was not sufficient to obtain satisfying grain yield without Zn application. The results indicate that sensitivity to Zn deficiency stress became more pronounced when plants were drought‐stressed. The effect of irrigation on grain yield was maximized when Zn was adequately supplied, leading to the suggestion that efficient water use in Central Anatolia seems to be highly dependent on the Zn nutritional status of plants. 相似文献
This study was carried out in order to identify the body measurements of two different Dromedary camel breeds raised in Algeria. The animal material of the study consisted of a total of 115 animals belong to Steppe (n?=?55) and Sahraoui (n?=?60) camel breeds. Eye and coat colors along with body measurements such as head length, neck length, neck girth, tail length, distance between eyes, distance between ears, body length, withers height, chest girth, and live weight were determined. Least squares means for head length, neck length, neck girth, tail length, distance between eyes, distance between ears, body length, withers height, chest girth, and live weight are found 48.2, 116.9, 65.7, 55.6, 24.1, 22.5, 152.2, 184.5, 141.2 cm, and 217.2 kg for Steppe and 48.1, 101.2, 56.2, 51.2, 23.4, 18.3, 135.6, 167.3, 176.8 cm, and 298.9 kg for Sahraoui camel breeds, respectively. The distribution of brown and black eye colors for the Steppe camel breed is as 58.2% and 41.8%, respectively, while all of the Sahraoui camels studied had a brown eye color. The proportional distribution in terms of body color included are coffee, dark coffee, and red colors for 1.8%, 83.6%, and 14.6% in the Steppe camel and 98.3%, 1.7%, and 0.0% for the Sahraoui camel, respectively. As a result, this study concluded that the withers height and chest girth could estimate the body weight in the two breeds of camels with different ages.
Polymyxa graminis is the vector of several important viruses, including Soilborne cereal mosaic virus, Wheat spindle streak mosaic virus, Barley yellow mosaic virus and Barley mild mosaic virus, of winter cereals worldwide. Surveys were carried out to detect these viruses and their vector P. graminis in 300 soil samples from the main wheat and barley production areas of the Anatolian part of Turkey collected in May 2002,
June 2004 and May 2005. For these surveys, various susceptible wheat and barley cultivars were pot grown in the collected
soil samples in a greenhouse and then analysed using ELISA and RT-PCR to detect the presence of different virus species. In
addition, a combination of light microscopy following roots staining with acid fuchsin and PCR was used for detection of P. graminis. All soil samples analysed were found to be free of these soilborne viruses and their vector. 相似文献