Economic Analysis of Stand-Alone Hybrid Wind/PV/Diesel Water Pumping System: A Case Study in Egypt

The design and evaluation of a stand-alone hybrid renewable energy system for pumping underground water for small farm irrigation is presented. Given environmental conditions, system specifications and daily load demand data, the optimal size of main system components is obtained using a sizing algorithm. Different renewable energy systems are compared using yearly simulations, on hourly base via specialized commercial software simulation packages PVSYST and HOMER, to simulate the system performance and to reach the optimum configurations based on the objective criteria. The criteria used in economic optimization are the net present cost and the cost of energy, with the percent of the capacity shortage. The following systems can be compared: PV only, PV with horizontal axis wind turbine, PV with vertical axis wind turbine, and PV with horizontal axis wind turbine and diesel generator and diesel generator only. The simulation also was carried out for different load patterns for optimum operation. The study was illustrated for climatic conditions of an isolated area in El-Tour City, Sinai, Egypt. The installed 3.42 kW PV water pumping system for irrigation purposes in the same site was also described

Tempol, a superoxide dismutase mimetic agent, ameliorates cisplatin-induced nephrotoxicity through alleviation of mitochondrial dysfunction in mice.

Mitochondrial dysfunction is a crucial mechanism by which cisplatin, a potent chemotherapeutic agent, causes nephrotoxicity where mitochondrial electron transport complexes are shifted mostly toward imbalanced reactive oxygen species versus energy production. In the present study, the protective role of tempol, a membrane-permeable superoxide dismutase mimetic agent, was evaluated on mitochondrial dysfunction and the subsequent damage induced by cisplatin nephrotoxicity in mice.Nephrotoxicity was assessed 72 h after a single i.p. injection of cisplatin (25 mg/kg) with or without oral administration of tempol (100 mg/kg/day). Serum creatinine and urea as well as glucosuria and proteinuria were evaluated. Both kidneys were isolated for estimation of oxidative stress markers, adenosine triphosphate (ATP) content and caspase-3 activity. Moreover, mitochondrial oxidative phosphorylation capacity, complexes I-IV activities and mitochondrial nitric oxide synthase (mNOS) protein expression were measured along with histological examinations of renal tubular damage and mitochondrial ultrastructural changes. Tempol was effective against cisplatin-induced elevation of serum creatinine and urea as well as glucosuria and proteinuria. Moreover, pretreatment with tempol notably inhibited cisplatin-induced oxidative stress and disruption of mitochondrial function by restoring mitochondrial oxidative phosphorylation, complexes I and III activities, mNOS protein expression and ATP content. Tempol also provided significant protection against apoptosis, tubular damage and mitochondrial ultrastructural changes. Interestingly, tempol did not interfere with the cytotoxic effect of cisplatin against the growth of solid Ehrlich carcinoma.This study highlights the potential role of tempol in inhibiting cisplatin-induced nephrotoxicity without affecting its antitumor activity via amelioration of oxidative stress and mitochondrial dysfunction

Effect of tempol on cisplatin-induced changes in light microscopic examination (H&E x200) in renal tissues of mice.

<p>(A) normal group and (B) tempol-treated group show normal non-affected tubular epithelium (thick dark arrow). (C) cisplatin-treated group shows severe tubular damage as revealed by acute tubular necrosis (dashed thick arrow), wide tubular epithelial vacuolation (v), apoptotic tubular epithelium (thick white arrow) and cast formation (s). (D) tempol and cisplatin-treated group shows more or less normal renal tubules with minimal focal vacuolation of the tubular epithelium (v). (E) renal injury score. Mice were studied 72 h after a single i.p. injection of cisplatin (25 mg/kg). Tempol (100 mg/kg/day) was given orally for 4 days starting one day before cisplatin injection. Each renal injury score value represents the mean of 4 mice ± S.E.M. *<i>p<0.05 vs.</i> normal, ^#<i>p<0.05 vs</i>. cisplatin.</p

Effect of tempol, cisplatin and their combination on the growth of solid Ehrlich carcinoma 72 h after starting treatment.

<p>Mice with a palpable solid tumor mass (100 mm³) were given a single i.p. injection of cisplatin (25 mg/kg) or tempol orally in a dose of 100 mg/kg/day or a combination of tempol and cisplatin. The change in tumor volume was measured after 3 days using a Vernier caliper. Each value represents the mean of 5–6 mice ± S.E.M. ^$<i>p<0.05 vs</i>. control.</p><p>Effect of tempol, cisplatin and their combination on the growth of solid Ehrlich carcinoma 72 h after starting treatment.</p

Effect of tempol on cisplatin-induced changes in mitochondrial complexes I–IVactivities, oxidative phosphorylation capacity and adenosine triphosphate (ATP) content in renal tissues of mice.

<p>Mice were studied 72 h after a single i.p. injection of cisplatin (25 mg/kg). Tempol (100 mg/kg/day) was given orally for 4 days starting one day before cisplatin injection. Each value represents the mean of 6–8 mice ± S.E.M. *<i>p<0.05 vs.</i> normal, ^#<i>p<0.05 vs</i>. cisplatin.</p><p>Effect of tempol on cisplatin-induced changes in mitochondrial complexes I–IVactivities, oxidative phosphorylation capacity and adenosine triphosphate (ATP) content in renal tissues of mice.</p

Effect of tempol on cisplatin-induced changes in mitochondrial ultrastructural examination of renal tissues in mice.

<p>Photomicrographs are representative specimens which show mitochondria (m) and cytoplasm (c) from normal group (A x2,000 magnification; B x10,000 magnification), tempol-treated group (C x2,000 magnification; D x10,000 magnification), cisplatin-treated group (E x2,000 magnification; F x10,000 magnification), tempol and cisplatin-treated group (G x2,000 magnification; H x10,000 magnification), mitochondrial overall injury score (I) and percentage of mitochondrial cross-sectional area/cytoplasmic area (J). Mice were studied 72 h after a single i.p. injection of cisplatin (25 mg/kg). Tempol (100 mg/kg/day) was given orally for 4 days starting one day before cisplatin injection. Each value represents the mean of 4 mice ± S.E.M. *<i>p<0.05 vs.</i> normal, ^#<i>p<0.05 vs</i>. cisplatin.</p

Effect of tempol on cisplatin-induced changes in oxidative stress markers in postmitochondrial and mitochondrial fractions in renal tissues of mice.

<p>(A) Reduced glutathione (GSH). (B) Thiobarbituric acid reactive substances (TBARS). Mice were studied 72 h after a single i.p. injection of cisplatin (25 mg/kg). Tempol (100 mg/kg/day) was given orally for 4 days starting one day before cisplatin injection. Each value represents the mean of 6–8 mice ± S.E.M. *<i>p<0.05 vs.</i> normal, ^#<i>p<0.05 vs</i>. cisplatin.</p

Effect of tempol on cisplatin-induced changes in antioxidant enzymes activities in postmitochondrial and mitochondrial fractions in renal tissues of mice.

<p>(A) Superoxide dismutase (SOD). (B) Catalase. Mice were studied 72 h after a single i.p. injection of cisplatin (25 mg/kg). Tempol (100 mg/kg/day) was given orally for 4 days starting one day before cisplatin injection. Each value represents the mean of 6–8 mice ± S.E.M. *<i>p<0.05 vs.</i> normal, ^#<i>p<0.05 vs</i>. cisplatin.</p