Design of Experiment (DoE) as a statistical method was applied for optimizing lipid extraction conditions from scum sludge. Four different extraction variables were optimized namely methanol to hexane ratio (%), solvent to sludge ratio (ml/g), temperature (oC), and extraction time (h). Process optimization was conducted through three main steps: 1) 2k factorial screening design; 2) Steepest ascent method; and 3) Box-Behnken design and response surface method. Based on 2k factorial screening design, methanol to hexane ratio, solvent to sludge ratio and temperature were identified as highly significant variables affecting lipid extraction from scum sludge. Based on screening results, the steepest ascent method was used followed by Box-Behnken design and Response Surface Method (RSM) were then applied for optimization. The maximum extracted lipid of 29.4% (wt lipid/wt dry sludge- %) was achieved at 40% methanol to hexane ratio (%), 40 solvent to sludge ratio (ml/g), 90oC and 6 hours extraction time. The results revealed that lipid extraction increases with reducing the methanol to hexane ratio, increasing solvent to sludge ratio and increasing temperature The results demonstrated the potentiality of scum sludge for biodiesel production from scum sludge compared with the amount of lipid extracted from primary and secondary sludge reported by other studies. Keywords: Box-Behnken design, Design of Experiment (DoE), lipid extraction, Scum sludge, response surface method (RSM). Article History: Received Feb 16th 2017; Received in revised form May 5th 2017; Accepted June 4th 2017; Available onlineHow to Cite This Article: Ibrahim, S.N.H, and Hamza, E.A. (2017). Optimization of Lipid Extraction from Municipal Scum Sludge for Biodiesel Production Using Statistical Approach. International Journal of Renewable Energy Development, 6(2), 171-179.https://doi.org/10.14710/ijred.6.2.171-179

Eight isolates of the Cucumber mosaic virus (CMV) were isolated from cucumber (Cucumis sativus) and zucchini (Cucurbita pepo) plants showing symptoms matched the CMV infection. The identity of these isolates was confirmed as CMV based on diagnostic hosts reaction, enzyme-linked immunosorbent assay (ELISA), and electron microscopy. The identification was confirmed at the molecular level. The obtained isolates were mechanically transmitted to diagnostic hosts which produced typical symptoms of CMV infection on each plant. Also, its easily transmitted by aphid (Aphis gossypii) in non-persistent manner. The virus could be transmitted through seeds of pumpkin, zucchini, and cucumber but not through seeds of melon. A variation in aggressiveness between obtained isolates were observed. Evaluating the disease reaction of some cultivated cucurbit types toward CMV artificially infection reveled that all the tested types were susceptible but differed in their susceptibility rate.

Background: Cerebrospinal fluid (CSF) shunts remain among the most failure-prone lifesustaining medical devices implanted in modern medical practice, with failure rates of 30-40% at 1 year and approximately 50% at 2 years in pediatric patients. Aim of the Work: To study the effectiveness of antimicrobial impregnated catheters in preventing shunt and EVD infections and the impact of antibiotic impregnated catheters on mortality, and prevention colonization. Methods: The PubMed and Scopus databases were searched. Catheter implantation was classified as either shunting (mainly ventriculoperitoneal shunting) or ventricular drainage (mainly external [EVD]). Studies evaluating antibioticimpregnated catheters (AICs), silver-coated catheters (SCCs), and hydrogel-coated catheters (HCCs) were included. A random effects model meta-analysis was performed. Results: Thirty-six studies (7 randomized and 29 nonrandomized, 16,796 procedures) were included. The majority of data derive from studies on the effectiveness of AICs, followed by studies on the effectiveness of SCCs. Statistical heterogeneity was observed in several analyses. Antimicrobial shunt catheters (AICs, SCCs) were associated with lower risk for CSF catheter-associated infections than conventional catheters (CCs) (RR 0.44, 95% CI 0.35-0.56). Fewer infections developed in the patients treated with antimicrobial catheters regardless of randomization, number of participating centers, funding, shunting or ventricular drainage, definition of infections, de novo implantation, and rate of infections in the study. There was no difference regarding gram-positive bacteria, all staphylococci, coagulase-negative streptococci, and Staphylococcus aureus, when analyzed separately. On the contrary, the risk for methicillin-resistant S. aureus (MRSA, RR 2.64, 95% CI 1.26-5.51), nonstaphylococcal (RR 1.75, 95% CI 1.22-2.52), and gram-negative bacterial (RR 2.13, 95% CI 1.33-3.43) infections increased with antimicrobial shunt catheters. Conclusion: The use of antimicrobial shunt catheters reduces the risk for CSF infections in patients with hydrocephalus. Several subgroup analyses showed that factors related to study design, type of catheter, duration of catheter placement, and whether the procedure is a de novo implantation or a revision may affect this risk. Publication bias in the region of small negative trials was also observed.

Introduction: Schwannomas are benign, slow-growing wellencapsulated tumors. Peripheral nerve sheath tumors are those that develop from Schwann cells that surround the peripheral or cranial nerves. Aim Of The Work:To assess the efficacy of various treatment modalities for trigeminal schwannoma.