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1.
The hypothesis that the presence of fish farming zones affects the water quality and plankton communities was investigated in an Aegean Sea fish farm during February, June, September and January 2000–2001. In the spatial coverage, a total of 12 stations were sampled; three of them were reference stations. A variance analysis was applied to the measurements made at the stations near the fish farms and at the control stations. While no significant differences in concentrations of nutrients, chlorophyll a, particulate organic carbon and particulate organic nitrogen were detected between the stations and the control sites within one season, significant differences were detected between the parameter values measured except for total dissolved phosphorus and dissolved organic phosphorus at different seasons. The seasonal differences were also significant with regard to the biodiversity. Together with these temporal differences in general, there was a higher diversity of species at the control site as compared with the other stations in September, which was the key season to detection of significant changes. The most important consideration is that it is not sufficient to take the instantaneous values for the physico‐chemical variables; rather, it is necessary to monitor the biological parameters in order to define the differences in the ecosystem. 相似文献
2.
The distribution of mast cells (MCs) was studied in the lymphoid organs (thymus, bursa of Fabricius and spleen) of 0-, 7-, 21-, 30- and 120-day-old chickens, using light microscopic histochemical techniques. Tissues samples were obtained under deep anaesthesia from animals in five groups. Tissues were fixed in Mota's fixative (basic lead acetate) for 24 h and embedded in paraffin. Six-micrometre-thick sections were stained with toluidine blue in 0.5% aqueous solution at pH 1.0 for 5 min and Alcian blue/Safranine at pH 1.42 for 30 min. MCs were found in the organs, mostly associated with sinuses and blood vessels. A large increase in MCs was observed in both thymus and spleen of 21-day-old chickens compared with 0-, 7-, 30- and 120-day-old chickens. However, in the bursa of Fabricius, numbers of MCs were significantly higher in the 7-day-old group compared with other age groups. Safranine-positive MCs were not observed in all organs and age groups. These results showed age-related changes in the number of MCs in avian lymphoid tissues. 相似文献
3.
Phyllo sheets were produced with flour obtained at different extraction rates (53, 58, or 67%), and stored at 4 and 25°C. Physical, chemical, and sensory properties of fresh and stored phyllo were researched. Fresh phyllo samples from wheat flour at 53% extraction rate were thinner (0.4 mm) and had whiter color (L* = 87.6). Textural properties and overall sensory acceptability of phyllo samples significantly decreased (P ≤ 0.01) with increased extraction rates and storage times. At the end of four days, toughness and extensibility decreased from 0.88 N and 10.9 mm to 0.65 N and 6.7 mm at 4°C and to 0.45 N and 5.6 mm at 25°C. The 53% extraction rate was more suitable for producing phyllo. The shelf life of phyllo samples for preparing borek was determined four days at 4°C and two days at 25°C according to acid contents and sensory properties. 相似文献
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5.
Nano-TiO2 based multilayer nanocomposite films were fabricated on cationically modified woven cotton fabrics by layer-by-layer molecular
self-assembly technique. Cationization process was used to obtain cationic surface charge on cotton fabrics. Attenuated total
reflectance Fourier transform infrared spectroscopy analyses were used to verify the presence of cationic surface charge and
multilayer films deposited on the fabrics. Scanning electron microscope micrographs of poly(sodium 4-styrene sulfonate)/TiO2, nano polyurethane/TiO2, and TiO2/poly(diallyldimethylammonium chloride) multilayer films deposited on cotton fabrics were taken. With nano-TiO2 based multilayer film deposition, the protection of cotton fabrics against UV radiation is enhanced. The UV protection durability
of the self-assembled multilayer films deposited on the cotton fabrics was analyzed after 10 and 20 washing cycles at 40 °C
for 30 min. Air permeability and whiteness value analysis were performed on the untreated and multilayer film deposited cotton
fabrics. The effect of layer-by-layer deposition process on tensile strength properties of the warp and weft yarns was determined. 相似文献
6.
Dielectric properties and ac electrical conductivity (σ
ac
) of Au/PVA(Co, Zn acetate)/n-Si and Au/PVA(Ni, Zn acetate)/n-Si Schottky diodes (SDs) have been investigated in dark and
under illumination by using experimental capacitance-voltage (C-V) and conductance-voltage (G/ω-V) measurements at 1 MHz and room temperature. Experimental results indicate that the change in dielectric constant (ɛ′), dielectric loss (ɛ″), loss tangent (tanδ), the real (M′) and imaginary (M″) parts of electric modulus and ac electrical conductivity (σ
ac
) with illumination were found to change linearly with illumination level (P). On the other hand, the ɛ′, ɛ″, tanδ and σ
ac
vs P have positive slope while the M′ and M″ vs P have negative slope. Such behavior of dielectric properties and σ
ac
can be attributed to illumination induced electron-hole pairs under illumination effect in the depletion region of SDs. The
obtained results under illumination suggest that these devices can be used as a sensor in optical applications. 相似文献
7.
Boron doped PVA/Zr-Al acetate nanofibers were prepared by electrospinning using PVA as a precursor. The effect of calcination
temperature on morphology and crystal structure was investigated at 250, 500, and 800 °C. The study also establishes the effect
of boron doping on the morphology of PVA/Zr-Al acetate nanofibers at various calcination temperatures. The measurements showed
that the conductivity, pH, viscosity and the surface tension of the hybrid polymer solutions have increased with boron doping.
In addition, the fibers were characterized by FTIR, DSC, XPS, XRD and SEM techniques. The addition of boron did not only increase
the thermal stability of the fibers, but also increased the average fiber diameters, which gave stronger fibers. The DSC results
indicated that the melting temperature (Tm) of the fibers was increased from 256 to 270 °C with the addition of boron. XRD
peak patterns showed that after further heat treatment at 800 °C, zirconia exists in two phases of tetragonal and monoclinic
modifications. Moreover, alumina does not transform into the γ-Al2O3 and θ-Al2O3 phase at 800 °C. The SEM appearance of the fibers showed that the addition of boron resulted in the formation of crosslinked
bright surfaced fibers. 相似文献
8.
Uslu Barış Atalay Kocyigit Alper Sendag Sait Gülyüz Fetih Wehrend Axel 《Tropical animal health and production》2020,52(2):497-502
Tropical Animal Health and Production - The objective of this article was to investigate the efficiency of GnRH administrations at different time points after induced luteolysis on pregnancy rates... 相似文献
9.
Rhizobium spp. (local isolate) was used to inoculate three bean (Phaseolus vulgaris L.) varieties; Akman 98, G?ynük 98 and Sehirali 90, in a factorial field experiment. The objective of the experiment was to study effect of inoculation on seed yield, protein range, seed weight, non-soaker capacity and hydration index. Rhizobium spp. inoculation and nitrogen fertilizer significantly increased characters tested. This study revealed that inoculation with Rhizobium spp. improved seed quality. 相似文献
10.
M. Ötker Uslu A. Yediler I. Akmehmet Balcıoğlu S. Schulte-Hostede 《Water, air, and soil pollution》2008,190(1-4):55-63
A simple analytical method for the quantitative analysis of fluoroquinolone group antibiotics, enrofloxacin (ENR) and ciprofloxacin (CIP) in soil was developed based on the mechanical extraction with vortex and ultrasonication and solid phase extraction followed by high pressure liquid chromatography-fluorescence detection (HPLC-FLD). Type of extraction solvents and number of extraction cycles were optimized during the method development. The most efficient extraction solvent was found as phosphate buffer at pH 3 in combination with 50% of organic modifier acetonitrile with the extraction cycle of four. Overall method was applied on three different types of soils, namely, sandy, loamy sand and sandy loam and recovery rates ranged between 71–100% for ENR and 61–89% for CIP depending on the portion of organic and clay content in soils. The analytical method was also used for the estimation of fluoroquinolone concentrations in manure amended agricultural soils sampled from the different parts of Turkey and enrofloxacin was detected in the concentration range of 0.013–0.204 mg/kg. In addition, sorption of fluoroquinolone antibiotics on all types of soils was investigated and the highest distribution coefficients (Kd and Kf) of fluoroquinolone compounds were obtained for loamy sand (Kd?=?1.29 l/g and Kf?=?0.66 for CIP; Kd?=?0.97 l/g and Kf?=?0.56 for ENR) with the highest organic carbon. 相似文献