893 resultados para Unsaturated polyester


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The purpose of this study, Evaluation the effect of Rosmarinus officinalis and Thymus vulgaris extracts on the stability of poly unsaturated fatty acids in frozen Silver carp minced. Treatments include: Treatment 1 - Control: frozen meat packaged in conventional Treatment 2: Frozen Silver carp minced+Thyme 300 mg/kg in normal packaging Treatment 3: Frozen Silver carp minced+Rosemary 200 mg/kg in normal packaging Treatment 4: Frozen Silver carp minced+Rosemary compound (100 mg/kg) and Thyme (100 mg/kg) in normal packaging After rapid freezing of samples in the spiral freezer by individual quick freezing method, to maintain the cold temperature (-18) °C were transferred. Sampling and measurements to determine the fatty acid profile of the zero phase beginning in the first month and then every ten days, and 15 days in the second month of the third month after the monthly test. Identifying, defining and measuring the fatty acid profile by gas chromatography was performed. In this study, levels of both saturated and unsaturated fatty acids in three experimental and one control were identified as follows: A: saturated fatty acids: Meristic C14: 0/Palmitic C16: 0/Hepta decaenoic C17: 0/Stearic C18: 0/Arashidic C20: 0/B:Mono unsaturated fatty acids: palmitoleic C16: 1-W7/Oleic C18: 1-W9/Gadoleic C20: 1-W9 C:Poly unsaturated fatty acids: Linoleic C18: 2-W6/α-Linolenic C18: 3-W3 D:High unsaturated fatty acids: Arachidonic C20: 4-W6 Eicosapentaenoic acid C20: 5-EPA/W3 Docosahexaenoic C22: 6-DHA/W3 Results of this study was to determine, Thyme and rosemary extracts containing silver carp minced stored in freezing conditions, Stability of different types of fatty acids, monounsaturated fatty acids, poly-unsaturated fatty acids, omega-3 and omega-6 fatty acids are. So that none of the fatty acids measured were not significant 100% increase or decrease, While changes in the fatty acid oxidation during storage time is minimized. The results obtained from the fatty acid profiles and indicators of their and statistical tests show that treatment with rosemary extract More stable during storage (-18) ° C In comparison with the control and other treatments are shown; And at relatively low compared to other treatments and control samples oleic acid and linoleic acid, palmitic more. According to studies,in Silver carp minced that containing rosemary extract, end of the storage period of six months. Were usable, so even rosemary extract the shelf-life examples to increase more than six months.

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This experiment was conducted to investigate the effect of using n-3 HUFA and Vitamin C enriched Artemia urmiana Nauplii Five difference treament were tested: for Caspian salmon (Salmo trutta caspius) larvae compare with artificial food in five treatment: (1) Artificial food, (2) Newly hatched Artemia (3) n-3 HUFA enriched Artemia (4) n-3 HUFA + 10% Ascorbyl Palmitate enriched Artemia (5) n-3 HUFA+20% Ascorbyl palmitate enriched Artemia during 15 days then all treatment were fed with artificial food during 20 days. In days of 15, larvae fed with newly hatched Artemia didn’t show significant difference of growth rate and survival compared to larvae fed with n-3 HUFA and Vitamn C enriched live food (p<0.05), However all treatment which fed live food have better growth rate and survival compred to larvae fed artificial food. Larvae fed with enriched Artemia with n-3 HUFA + 20% Ascorbyl palmitate has best result of temperature resistance at 26'C and 28'C. There is not significant difference between treatment (1) and (2), (3) and in this manner between (2), (3) and (4), (5) (P>0.05). In days of 35, larvae fed n-3 HUFA + 10% and 20% Ascorbyl pamlitate show better wet weight and dry weight compared to other treatment (P<0.05). Larvae fed n-3 HUFA Artemia showed significant difference compared to treatment (1) and (2), However there is not significant difference between treatment (1) and (2). Larvae fed artificial food show less and significant difference of survival compared to other treatment (P<0.05). Larvae fed artificial food show least of temperature resistance at 26'C and 28'C , However, there is not significant difference between all treatment (P<0.05).

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In this experiment, the feeding of Indian white shrimp larvae by unenriched rotifers (treatment 1) and enriched with highly unsaturated fatty acid (treatment 2) and highly unsaturated fatty acid along with vitamin C (treatment 3) on the growth factors, survival and resistance against salinity and formalin stress tests were studied and their differences with control treatment including newly hatched Artemia nauplii is compared. In this the study four treatments in a completely randomized design with 3 replicates per treatment were used. Farming of shrimp larvae of Zoea II to postlarvae 5 was done in 20 liter plastic bucket. Present results indicated that growth factors and survival rate of stage Zoea II to postlarvae 1 in treatments 1, 2 and 3 improve rather than control in which this case was due to optimal size rotifer rather than Artemia nauplii. Also, treatments 2 and 3 feeding with oil liver cod emulsion enriched rotifer have the highest concentration of DHA (mg/g DW) and the ratio DHA/EPA in which due to have shown the highest growth factors and a significant difference (P<0.05) with treatments 1 and control. The highest survival at stage PL1 were observed in treatment 3 that was enriched with ascorbyl palmitate in which have to the synergistic properties of vitamin C rather than treatments 2, 1 and control and showed a significant difference (P<0.05). But in stage PL5 the highest amount of growth and survival rates were related to control treatment which showed a significant difference (P<0.05) with other treatments that control has higher size rather than treatments 1, 2 and 3. Also, among experiment treatments that the two treatments 2 and 3 due to enrichment had higher growth and survival rates compared with treatment 1 in which their differences have also been significant (P<0.05). In the case of stress tests, results indicated that the highest survival rate has been reported when specimens were offered a diet containing high levels of highly unsaturated fatty acids with vitamin C. So that in stage PL1 in the salinity stress tests 10 and 20 ppt the highest survival rate was observed in treatment 3. As for the second, treatment 2 showed a significant difference (P<0.05) with treatment 3. It is worth mentioning that treatment 3 showed a higher survival rate compared to treatment 2 due to the synergistic properties of vitamin C. The difference between these two treatments with treatment 1 and control was also significant. No significant difference was observed in formalin stress test 100 ppm in this stage between treatments 3 and 2 which shows the highest survival rate. But their difference with treatments 1 and control was significant (P<0.05). Also, in stage PL5 in the salinity stress tests 10 and 20 ppt the highest survival rate was observed in treatment 3 which showed no significant difference (P<0.05) with control treatment. While their difference in the amount of survival rate with treatment 1 and 2 was significant (P<0.05). In this stage, the highest observed survival rate in formalin stress test 100 ppm included treatments control, 3 and 2 among which there were no significant differences (P<0.05). While the difference between these three treatments with treatment 1 was significant.

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The movement of chemicals through soil to groundwater is a major cause of degradation of water resources. In many cases, serious human and stock health implications are associated with this form of pollution. The study of the effects of different factors involved in transport phenomena can provide valuable information to find the best remediation approaches. Numerical models are increasingly being used for predicting or analyzing solute transport processes in soils and groundwater. This article presents the development of a stochastic finite element model for the simulation of contaminant transport through soils with the main focus being on the incorporation of the effects of soil heterogeneity in the model. The governing equations of contaminant transport are presented. The mathematical framework and the numerical implementation of the model are described. The comparison of the results obtained from the developed stochastic model with those obtained from a deterministic method and some experimental results shows that the stochastic model is capable of predicting the transport of solutes in unsaturated soil with higher accuracy than deterministic one. The importance of the consideration of the effects of soil heterogeneity on contaminant fate is highlighted through a sensitivity analysis regarding the variance of saturated hydraulic conductivity as an index of soil heterogeneity. © 2011 John Wiley & Sons, Ltd.

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The atomic and electronic structures of saturated and unsaturated GaN nanotubes along the [001] direction with (100) lateral facets are studied using first-principles calculations. Atomic relaxation of nanotubes shows that appreciable distortion occurs in the unsaturated nanotubes. All the nanotubes considered, including saturated and unsaturated ones, exhibit semiconducting, with a direct band gap Surface states arisen from the 3-fold-coordinated N and Ga atoms at the lateral facets exist inside the bulklike band gap. When the nanotubes are saturated with hydrogen, these dangling bond bands are removed from the band gap, but the band gap decreases with increasing the wall thickness of the nanotubes.

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Hydrogenation of alpha,beta-unsaturated aldehydes (citral, 3-methyl-2-butenal, cinnamaldehyde) has been studied with tetrakis(triphenylphosphine) ruthenium dihydride (H2Ru(TPP)(4)) catalyst in a poly(ethylene glycol) (PEG)/ compressed carbon dioxide biphasic system. The hydrogenation reaction was slow under PEG/ H-2 biphasic conditions at H-2 4 MPa in the absence of CO2. When the reaction mixture was pressurized by a non-reactant of CO2, however, the reaction was significantly accelerated.

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IntroductionConventional polymers such as polyethyleneand polypropylene persistfor many years after landdisposal.Furthermore,plastics are often soiled byfood and other biological substances,making phys-ical recycling of those materials impractical andgenerally undesirable. In contrast,biodegradablepolymers disposed in bioactive environment are de-graded by the enzymatic action of microorganismssuch as bacteria,fungi,and algae.The worldwideconsumption of biodegradable polymers increasedfrom1.4×107kg in ...

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A kind of full-biodegradable film material is discussed in this article. The film material is composed of starch, PVA, degradable polyesters(PHB, PHB-V, PCL) with built plasticizer, a cross-linking reinforcing agent and a wet strengthening agent. It contains a high percentage of starch, costs cheap and is excellent in weather fastness, temperature resistance and waterproof and it could be completely biodegraded. The present paper deals mainly with a new technical route using a new type of electromagnetic dynamic blow molding extruder and some effects on mechanical properties of the system.

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A main-chain nonracemic chiral liquid crystalline polymer was synthesized from (R)-(-)4'-{w-[2-(p-hydroxy-o-nitrophenyloxy)-1-propyloxy]-1-decyloxyl-4-biphenylcarboxylic acid. This polymer contained 10 methylene units in each chemical repeating unit and was abbreviated PET(R*-10). On the basis of differential scanning calorimetry, wide-angle X-ray diffraction, and polarized light microscopy experiments, chiral smectic C (S-C*) and chiral smectic A (S-A*) phases were identified. Both flat-elongated and helical lamellar crystal morphologies were observed in transmission electron microscopy. Of particular interest was the flat-elongated lamellar crystals were constructed via microtwinning of an orthorhombic cell with dimensions of a = 1.42 nm, b = 1.28 nm, and c = 3.04 nm. On the other hand, the helical lamellar crystals were exclusively left-handed, which was opposite to the right-handed helical crystals grown in PET(R*-9) and PET(R*-11) (having 9 and 11 methylene units, respectively). Note that these three polymers had identical right-handed chiral centers (R*-). Therefore, a single methylene unit difference on the polymer backbones on an atomic length scale substantially changed the chirality of the crystals in the micrometer length scale. Furthermore, aggregates of these helical crystals in PET(R*-10) did not generate banded spherulites in polarized light microscopy. Possible reasons for this change and loss of helical senses (handedness) on different length scales in chirality transferring processes were discussed.