Spectrophotometric Determination of Carbofuran with Diazotized Benzidine in Environmental Water Samples

A simple, rapid, accurate and sensitive spectrophotometric method has been developed for the determing carbamate pesticides in both pure and water samples. The method is appropriate for the determination of carbofuran in the presence of other ingredients that are usually available in dosage forms. The effect of organic solvents on the spectrophotometric properties of the azo dye and the structure of the resulting product have also been worked out and it is found to be 1:1 benzidine :carbofuran. The method can be successfully applied to determination of carbofuran in water samples. The method is based on diazotization of Benzidine (4, 4 – diamino biphenyl) with sodium nitrite and hydrochloric acid followed by coupling with carbofuran in alkaline medium to form a yellow colored azo dye having the absorption maximum at 429nm against reagent blank solution. Beer’s law is obeyed in the concentration range of (0-14) ?g of 10mL carbofuran. Molar absorptivity of 1×104 L.mol-1.cm-1 which depend on the concentration level of carbofuran

Kinetic Study of Air Bubbles-Cetyltrimethylammonium Bromide (CTAB) Surfactant for Recovering Microalgae Biomass in a Foam Flotation Column

Owing to their efficient photosynthesis, microalgae tend to possess superior growth rates and high lipid production, hence their significance to the biofuel sector. The bulk harvesting of microalgae from cultures is a substantial stage in advancing the production of biomass-based fuels. However, a reliable and cost-effective harvesting technology is not yet available. Foam flotation, which is a subcategory of the adsorptive bubble separation process, shows considerable promise for the harvesting and enrichment of microalgae biomass. The available literature indicates that virtually no data has been reported on the flotation kinetics of microalgae. Therefore, to better describe the recovery of microalgae by the flotation process, this work studied the flotation kinetics of the freshwater microalgae Chlorella vulgaris. The recovery of microalgae cells in a batch foam flotation column over time at different operating conditions was fitted to nine flotation kinetic models, including first, fractional, and second order kinetic models; a first order kinetic model with rectangular, exponential, gamma, and sinusoidal distributions of floatabilities; a second order kinetic model with rectangular distribution of floatabilities; a fully mixed reactor; and modified Kelsall flotation kinetic models. Evaluation of the kinetic models showed that the discrete rate constant model (i.e. modified Kelsall kinetic model) fitted the experimental data best. The modified Kelsall model shows the highest values of adjusted R2 (>0.995) and the lowest values of mean squared error (<2.63). Apart from the modified Kelsall model, which has discrete rate constants, no single kinetic model, with or without a continuous distribution, was sufficient to represent the flotation data, and the optimal model may vary under different conditions. More work is recommended using different freshwater and marine microalgae species

Utilization of High Volume Fraction of Binary Combinations of Supplementary Cementitious Materials in the Production of Reactive Powder Concrete

The reactive powder concrete (RPC) is one of the special concrete types that characteristics with high cement content which means high production cost and CO2 emissions to the atmosphere. Therefore, to enhance the environment as well as to develop green RPC, alternatives to cement, such as supplementary cementitious materials (SCMs) were used. Limited studies addressed the use of a high volume fraction of SCMs as a binary combination in the production of RPC. Thus, this study aims to replace a high percentage of cement (50%) with binary combinations of silica fume (SF), type F fly ash (FA) and metakaolin (MK). The experimental program included two phases. In phase one, two groups (SF+FA and MK+FA) were cast without steel fibers. Based on group performance in the first phase, one group was chosen to be used with steel fibers in the second phase. The flow rate, compressive and flexural strengths, density, ultrasonic pulse velocity and dynamic modulus of elasticity tests were conducted. The phase one results showed that SF+FA combination mixtures had better performance than MK+FA mixtures thus they were selected to be used in the second phase (with the addition of 1% volumetric fraction micro steel fibers). Results indicated that it is possible to produce sustainable RPC in which the cement can be replaced with 30% SF and 20% FA (the total replacement is 50%) in the presence of 1% steel fibers with a remarkable enhancement in compressive strength and flexural strength reached up to 44% and 10%, respectively

Acoustic Neuroma (Vestibular Schwannoma)

Acoustic neuroma is also called vestibular schwannoma (VS), acoustic neurinoma, vestibular neuroma or acoustic neurofibroma. These are tumors that evolve from the Schwann cell sheath and can be either intracranial or extra-axial. They usually occur adjacent to the cochlear and vestibular nerves and most often arise from the inferior division of the latter. Anatomically, acoustic neuroma tends to occupy the cerebellopontine angle. About 5-10% of cerebellopontine angle (CPA) tumors are meningiomas and may occur elsewhere in the brain. Bilateral acoustic neuromas tend to be exclusively found in individuals with type 2 neurofibromatosis

Acoustic Neuroma (Vestibular Schwannoma)

Acoustic neuromas are also called vestibular schwannoma, acoustic neurinoma, vestibular neuroma, and acoustic neurofibroma. These are tumors that evolve from Schwann cell sheath and can be either intracranial or extra-axial. They usually occur adjacent to the cochlear or vestibular nerve. Anatomically, acoustic neuromas tend to occupy the cerebellopontine angle. About 20% of internal carotid artery (ICA) tumors are meningiomas and may occur elsewhere in the brain. Bilateral acoustic neuromas also tend to be exclusively in individuals with type 2 neurofibromatosis

Sepsis and septic shock after craniotomy: Predicting a significant patient safety and quality outcome measure.

ObjectivesSepsis and septic shock are important quality and patient safety metrics. This study examines incidence of Sepsis and/or septic shock (S/SS) after craniotomy for tumor resection, one of the most common neurosurgical operations.MethodsMulticenter, prospectively collected data from the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) database was used to identify patients undergoing craniotomy for tumor (CPT 61510, 61521, 61520, 61518, 61526, 61545, 61546, 61512, 61519, 61575) from 2012-2015. Univariate and multivariate logistic regression models were used to identify risk factors for S/SS.ResultsThere were 18,642 patients that underwent craniotomy for tumor resection. The rate of sepsis was 1.35% with a mortality rate of 11.16% and the rate of septic shock was 0.65% with a 33.06% mortality rate versus an overall mortality rate of 2.46% in the craniotomy for tumor cohort. The 30-day readmission rate was 50.54% with S/SS vs 10.26% in those without S/SS. Multiple factors were identified as statistically significant (p 310 minutes (OR = 1.5), hypertension requiring medication (OR = 1.5), ASA class ≥ 3 (OR = 1.4), male sex (OR = 1.4), BMI >35 (OR = 1.4) and infratentorial location.ConclusionsThe data indicate that sepsis and septic shock, although uncommon after craniotomy for tumor resection, carry a significant risk of 30-day unplanned reoperation (35.60%) and mortality (18.21%). The most significant risk factors are ventilator dependence, ascites, SIRS and poor functional status. By identifying the risk factors for S/SS, neurosurgeons can potentially improve outcomes. Further investigation should focus on the creation of a predictive score for S/SS with integration into the electronic health record for targeted protocol initiation in this unique neurosurgical patient population