Hourly Price-Based Demand Response for Optimal Scheduling of Integrated Gas and Power Networks Considering Compressed Air Energy Storage

Gas-fired plants are becoming an optimal and practical choice for power generation in electricity grids due to high efficiency and less emissions. Such plants with fast start-up capability and high ramp rate are flexible in response to stochastic load variations. Meanwhile, gas system constraints affect the flexibility and participation of such units in the energy market. Compressed air energy storage (CAES) as a flexible source with high ramp rate can be an alternative solution to reduce the impact of gas system constraints on the operation cost of a power system. In addition, demand response (DR) programs are expressed as practical approaches to overcome peak-demand challenges. This study introduces a stochastic unit commitment scheme for coordinated operation of gas and power systems with CAES technology as well as application of an hourly price-based DR. The introduced model is performed on a six-bus system with a six-node gas system to verify the satisfactory performance of the model

Influence of coating morphology on adhesive bonding of titanium pre-treated by plasma electrolytic oxidation

AbstractThe effect of plasma electrolytic oxidation (PEO) pre-treatments on the adhesive bonding of titanium is investigated using lap-shear tests. Two pre-treatments are compared, using aluminate-phosphate and silicate-phosphate electrolytes respectively, which result in different compositions and morphologies of coatings. Specimens were joined with an epoxy adhesive. The PEO-treated specimens revealed mainly cohesive failure within the titanium-rich inner coating regions, which contrasted with the adhesive failure of untreated titanium. The silicate-phosphate pre-treatment resulted in the infiltration of a highly porous outer region of the coating by the adhesive. The fracture of the coatings occurred close to the titanium/coating interface and intersected the bases of relatively large pores, which in the case of the aluminate-phosphate coating lay beneath nodules that were evident at the coating surface. The pre-treatments did not significantly increase the lap-shear strength in comparison with untreated titanium

Strong association between serum Vitamin D and Vaspin Levels, AIP, VAI and liver enzymes in NAFLD patients

Some studies indicated poor vitamin D level in NAFLD which is independently correlated with severity of steatosis. Low 25(OH) D3 levels are associated with an impaired lipid profile. Impaired levels and function of vaspin and omentin, which are adipokines, have been demonstrated in NAFLD patients. This study determined the relationship between vitamin D and serum liver enzymes, ultrasound findings, some adipokines, atherogenic index of plasma (AIP) and visceral adiposity index (VAI) in patients with NAFLD in a cross-sectional study. This study was a cross-sectional study in eighty-three NAFLD patients (57 males and 26 females). Plasma levels of omentin-1e-1, vaspin were measured. Anthropometric indices metabolic status was assessed. Visceral adiposity index and atherogenic index of plasma were calculated according to suggested formula. Anthropometric indices, lipid profiles, liver enzymes as well as abdominal ultrasonography and the status of vitamin D were assessed. The results showed that aspartate aminotransferase (AST) (44.22 ± 8.5 IU/L vs. 40.19 ± 8.75 IU/L, p-value = 0.039) AIP (0.767 ± 0.142 vs. 0.6417 ± 0.139, p < 0.001) and VAI (9.28 ± 3.25 vs. 7.048 ± 2.415, p = 0.001) were significantly higher in patients with vitamin D deficiency compared to those with vitamin D sufficiency. The positive correlations between Vaspin levels and vitamin D were found to be remarkably significant in both males and females (r = 0.437; P = 0.004; P < 0.001, r =-0.709, respectively. In both males and females serum vitamin D concentrations were negatively associated with AIP. Partial correlations controlling for age and sex showed that vitamin D is significantly and inversely associated with AIP, VAI, AST, and ALT. Additionally, vitamin D levels correlated directly with vaspin

Ramadan fasting improves liver function and total cholesterol in patients with nonalcoholic fatty liver disease

Background: Nonalcoholic fatty liver disease (NAFLD) is a serious global health problem, thus the prevention and management of the disease is necessary. This study aimed to determine the effects of Ramadan Fasting (RF) on liver function, Visceral Adiposity Index (VAI) and Atherogenic Index of Plasma (AIP) in these patients.Methods: Eighty-three NAFLD patients (57 males and 26 females) were enrolled in the study, 42 patients who practiced RF, between Jun 18 through July 17, 2015 and 41 patients in non-fasting groups. Anthropometric parameters and Ultrasound grading were measured before and after Ramadan. The biochemical parameters including lipid profiles (total cholesterol, LDL cholesterol, HDL cholesterol, and triglycerides), liver enzymes (Aspartate aminotransferase, SGOT and Alanine aminotransferase, SGPT) were evaluated before and after Ramadan. AIP and VAI were calculated based on formula.Results: The mean decreases in anthropometric indices were significantly different between groups. Similarly, the mean decrease in the total cholesterol values in the fasting group was remarkably greater than in the control group (p = 0.02). The values of AIP and VAI decreased at the end of the study in both group and the mean of changes showed no differences between groups (p = 0.79 and p = 0.65 for AIP and VAI, respectively). The changes in the concentrations of liver enzymes, as well as the severity of hepatic steatosis, showed remarkable differences between groups (p = 0.03, p = 0.05, and p = 0.02 for SGOT and SGPT, and Liver steatosis, respectively).Conclusion: RF improved liver steatosis in NAFLD patients and might be useful in the management of NAFLD

Evaluation of sowing and harvesting date effects on yield and quality of five sugar beet cultivars in Jiroft region (autumn planting)

As water is the most restrictive factor in national agricultural production, it is necessary to take decreased water consumption and increased water us efficiency in crop production into consideration. Nowadays, spring sugar beet production areas are concentrated in the region with water limitation and hence, the increase in spring production area contradicts the principle of water and soil conservation. Using new regions for autumn sugar beet sowing allows the increase in warm and semi-warm beet production areas. To develop sugar beet production in Province of Kerman and to find new climates, the study was conducted in Jiroft area in strip split split plots based on Randomized Complete Block Design (RCBD) with three replications during 2007-2008. Three sowing dates (September 6, October 7 and November 6), five cultivars (Rasoul, Monatuna, 9597, SBSI002 and SBSI003) and three harvesting dates (April 4, May 5 and June 5) were evaluated. Results showed significant effects of sowing and harvesting dates on white sugar yield. The effects of sowing date variations were greater than those of harvesting date so that growth period shortened by two months (due to delayed sowing date) decreased white sugar yield by 72.5% whereas and growth period prolonged by the same amount (due to delayed harvesting date) increased the white sugar yield by 55.1%. The highest white sugar yield (13.71 ton.ha-1) was obtained by early sowing (September 6) of SBSI002 and harvesting in May 5(with 240 days growth period). Considering favorable agro-climatic conditions in Jiroft region belonging to warm zone of Province of Kerman, it seems that the region has the potential for fall cultivation of sugar beet