123 research outputs found
Pressure management in water distribution systems in order to reduce energy consumption and background leakage
This is the author accepted manuscript. The final version is available from IWA Publishing via the DOI in this recordDue to the seriousness of the water shortage crisis over the past decades, the need to manage water use has become more and more important. Pressure management in urban water distribution networks is one of the options that can significantly reduce water loss. The pressure reducing valve (PRV) and the variable speed pump (VSP) are two devices that are most used in water distribution system (WDS) pressure management. In the present study, an optimization code was first proposed to estimate the instantaneous water demand based on the reported network pressures. According to the estimated instantaneous water demand, another optimization code is presented based on the DE algorithm to control the installed PRVs and VSPs. This results in the uniform distribution of the pressure and reduction of the excessive pressure on the water network for all hours of the day, reducing the water leakage and energy consumption accordingly. The provided method has been applied to a real water distribution network in northern Iran. The results showed that by applying this method, the network background leakage and the energy consumption have been reduced by 41.72% and 28.4%, respectively, compared to a non-management mode
Feeding regime of Persian sturgeon (Acipenser persicus) in the south Caspian Sea
Feeding regime of the Persian sturgeon in the southern basins of the Caspian Sea was studied in summer and winter 2006 in three provinces Guilan, Mazandaran and Golestan. We caught 52 fish specimens in 85 sampling sites varying in depths from 2-100 m using bottom trawls. The average weight and length of fish specimens were 332.81+1 g and 37.69±1 cm, respectively. The alimentary tract of fishes were analyzed and 11 food items including Gobiidae, Gammaridae, Mysidae, Nereidae, Ampharetidae, Pseudocumidae, Clupeidae, Syngnathidae, Scrobicularidae, insects and Cardiidae were identified. The highest feed diversity was observed in Mazandaran province (9 items) and the lowest in the Golestan province (4 items). Although Nereids showed the highest percentage of benthic organisms (49%) but they were of secondary and tertiary importance in the fish diet qualitatively. Comparison of Fulton's condition factor of fishes in the three provinces showed a similar pattern (0.3<1(<0.4). A tukey test revealed that there were no statistically significant differences between condition factor and gastrosomatic index in the three provinces while Vacuity index (CV) showed significant statistical differences among the provinces
Characterization and analysis of the interlaminar behavior of thermoplastic composites considering fiber bridging and R-curve effects
Thermoplastic composites can enable the development of new manufacturing techniques to make the aviation industry more sustainable while at the same time greatly benefit cost-efficient and high-volume production. One of the thermoplastic composite materials that can enable this transition is AS4D/PEKK-FC. In this work, the interlaminar properties of AS4D/PEKK-FC thermoplastic composite are characterized and analyzed by means of Mode I, II and Mixed Mode I/II at 50:50 tests, while considering fiber bridging and R-curve effects. In order to achieve stable crack propagation the test configurations are adjusted to account for the large fracture process zone ahead of the crack tip and an appropriate data reduction method is selected. The experimental data is reduced using an inverse methodology to extract cohesive laws based on only the load–displacement curves. Additionally, the use of this methodology provides new insights into the validity of two different mode II tests and the influence of fiber bridging on the mixed-mode interlaminar behavior. The interlaminar damage mechanisms are investigated by means of scanning electron microscopy. The resulting cohesive laws are implemented in commercial finite element software in tabular form, without the need for user-subroutines. All experimental test configurations are analyzed using a single material card and it is shown that fiber bridging and R-curve effects are well captured
Effect of Roasting on Fatty Acid Profile of Brown and Yellow Varieties of Flaxseed (Linum usitatissimum L)
Purpose: To monitor changes in fatty acid profiles of brown and yellow varieties of flaxseeds in the raw and roasted states using gas chromatography (GC).Methods: Samples of flaxseeds were extracted with n-hexane in a Soxhlet apparatus for 8 h. Methylesterification of the samples was performed by methanolic boron trifluoride (BF3-MeOH) method according to American Oil Chemists' Society (AOCS). Fatty acid (FA), analyzed using GC equipped with a split/splitless capillary injector and flame ionization detector (FID).Results: The results indicate that lipid content varied with the type of seed. Seed oil content was 53.31 ± 0.30 and 45.20 ± 0.20 % for roasted and unroasted brown flax, respectively, and 10.25 ± 0.04 % for the yellow type. The yellow and roasted brown type, at 300oC, showed the lowest and highest oil content, respectively. The highest calculated oxidizability (COX) value was found for the unroasted brown type (13.19 ± 0.01 %) whilst the lowest amount was observed for the roasted brown seed at 350oC (12.79 ± 0.01 %). COX value for yellow type was 5.62 ± 0.01 %.Conclusion: This study shows that the fatty acids content of flaxseeds vary with roasting conditions. This is significant because flax seed fatty acid composition influences the applications of the oil.Keywords: Oil, Flaxseed, Roasting, Fatty acid, Linum usitatissimum, Calculated oxidizability valu
Characterization of Inertial Electrostatic Confinement Fusion Plasma Device
Inetial electrostatic confinment fusion (IECF) device constructed at the Egyptian Atomic Energy Authority (EAEA-IEC), is introduced the characterization of the IEC plasma device. The x-ray and visible light emissions in IEC plasma device were investigated by employing time -resolved detector and measure of the total amount of visible light using lux meter
α-Amylase inhibitory property, antioxidant activity and toxicological study of Salvia chloroleuca
Abstract Background and objectives: Salvia chloroleuca Rech. f. & Allen., is an endemic species growing wildly in north east and center parts of Iran but there is no information about its safety. To provide information about the safety of the species, we evaluated its acute and sub chronic toxicity in rats. Methods: In acute toxicity study, the aqueous methanol (80%) extract at a single dose of 2000 mg/kg/day was administered orally to male and female rats and signs of toxicity two weeks after administration were observed. For the subchronic toxicity test, the extract at doses of 250, 500 and 1000 mg/kg/day were orally administered to the rats of both sexes for 45 days. Mortality, clinical signs of toxicity and body weight changes were monitored during the study. Moreover, α-amylase enzyme inhibition, total phenol content, and antioxidant (DPPH and FRAP assays) activity of different fractions of aerial part were evaluated. Results: The methanol and aqueous methanol (80%) extracts showed α-amylase enzyme inhibition with IC 50 values 14.03 mg/mL and 18.05 mg/mL, respectively. The IC 50 value for ethyl acetate, methanol and aqueous methanol (80%) extracts in radical scavenging assay were calculated as 288.83, 97.93, and 108.02 μg/mL, respectively. Among all extracts, methanol (228.4±12.05) demonstrated the highest FRAP value, followed by methanol (80%) extract (220.4±8.08) and ethyl acetate extract (156.4±10.06). In acute toxicity and subchronic study, neither mortality nor changes in behavior or any other parameter were observed. Conclusion: Our findings indicate potent in vitro α-amylase and antioxidant activity of S. chloroleuca and propose its potential as an anti-diabetic agent for treatment of noninsulin-dependent diabetes mellitus (NIDDM) patients
Essential oil analysis and antibacterial activity of Ferula assa-foetida L. aerial parts from Neishabour mountains
Abstract Background and objectives: Ferula assa-foetida (asafoetida) is a native Iranian species which grows in different regions and climates in Iran. The plant is well known in Iranian Traditional Medicine as well as folk medicine for treatment of diseases. Several studies have been carried out on the essential oil of this species collected from different areas of Iran. This study is the first report about the essential oil of the plant collected from Neishabour mountains that is a potent area for growing this valuable plant species. Methods: Essential oil of the aerial part of Ferula assa-foetida which was collected from Neishabour, Iran, was analyzed by gas chromatography-mass spectroscopy (GC/MS). The minimum inhibitory concentrations of the essential oil was investigated against both Grampositive (Staphylococcus epidermidis, Staphylococcus aureus, Bacillus subtilis) and Gram-negative (Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumonia) bacteria using microdilution method. Results: Twenty three components representing 97.06% of the total oil were identified. (E)-1-propenyl sec-butyl disulfide (53.77%), (Z)-1-propenyl sec-butyl disulfide (35.6%) and α-pinene (3.4%) were identified as major components. The MIC of the essential oil ranged from 12-24 mg/mL against all tested bacteria. Conclusion: The results indicated that among various compounds identified in the essential oil of F. assa-foetida L. from Neishabour mountains, disulphide compounds were the major constituents of the oil. In comparison to other reports of this plant around the country, disulphide compounds could be the reason of its moderate antibacterial effect
HIF1 alpha isoforms in benign and malignant prostate tissue and their correlation to neuroendocrine differentiation
Background: Neuroendocrine (NE) differentiation in prostate cancer has been correlated with a poor prognosis and hormone refractory disease. In a previous report, we demonstrated the presence of immunoreactive cytoplasmic hypoxia inducible factor 1 alpha (HIF1 alpha), in both benign and malignant NE prostate cells. HIF1 alpha and HIF1 beta are two subunits of HIF1, a transcription factor important for angiogenesis. The aim of this study was to elucidate whether the cytoplasmic stabilization of HIF1 alpha in androgen independent NE differentiated prostate cancer is due to the presence of certain HIF1 alpha isoforms.Methods: We studied the HIF1 alpha isoforms present in 8 cases of benign prostate hyperplasia (BPH) and 43 cases of prostate cancer with and without NE differentiation using RT-PCR, sequencing analysis, immunohistochemistry and in situ hybridization.Results: We identified multiple isoforms in both benign and malignant prostate tissues. One of these isoforms, HIF1 alpha 1.2, which was previously reported to be testis specific, was found in 86% of NE-differentiated prostate tumors, 92% of HIF1 alpha immunoreactive prostate tumors and 100% of cases of benign prostate hyperplasia. Immunohistochemistry and in situ hybridization results showed that this isoform corresponds to the cytoplasmic HIF1 alpha present in androgen-independent NE cells of benign and malignant prostate tissue and co-localizes with immunoreactive cytoplasmic HIF1 beta.Conclusion: Our results indicate that the cytoplasmic stabilization of HIF1 alpha in NE-differentiated cells in benign and malignant prostate tissue is due to presence of an HIF1 alpha isoform, HIF1 alpha 1.2. Co-localization of this isoform with HIF1 beta indicates that the HIF1 alpha 1.2 isoform might sequester HIF1 beta in the cytoplasm
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