Remediation of Crude Petroleum Oil-Water Emulsions Using Microalgae

Crude petroleum oil spills are among the most important organic contaminations, which result from uncontrolled releases and spillages during transportation or storage. The separated oils on that accumulate on top of the water can be removed by various conventional skimming methods. However, the emulsified portions that remain within the water phase are more difficult to remove and pose significant threats to the environment and could tamper the tertiary treatment in a wastewater treatment plant. Biological treatment, using bacteria, have proven to be an effective method in the removal of the emulsified oils. However, the biomass produced in this case does not have any significant remunerative value, and in most cases the used bacteria are pathogenic. In this work, microalgae have been proposed to be used, instead of bacteria, to combine the emulsified oil remediation with the microalgae potential as biofuel feedstock, which enhances the economic and environmental benefit of the process. A freshwater strain of Chlorella vulgaris was grown in water containing different concentrations of emulsified crude oil, up to 275 mg/L, at different temperatures. To enhance the removal of the emulsified oils, chemotrophic cultivation conditions was applied keeping the emulsified oils as a sole carbon source. The degradation was monitored by measuring the total organic carbon in the water. The specific growth rate of the microalgae at each initial oil concentration was determined and the results were fitted to a modified Monod kinetics model that takes specific interfacial area as the influential substrate, rather than the actual concentration. The microalgae growth was found to increase with the increase in temperature, in tested range, with μmax increasing from 1.17-1.48 day−1 as the temperature increased from 30oC and 40oC, and the activation energy was found to be 19.05 kJ/mol. However, the increase in the microalgae growth with temperature did not result increase on the oils removal and the yield of oil removal per biomass growth was found to decrease with the increase in temperature

Spectrophotometric determination of thrombin in pure samples and biological fluids using π-acceptors

Thrombin is the central enzyme of coagulation. It is engaged in opposing functions in blood. As a procoagulant factor, it converts fibrinogen into an insoluble fibrin clotand activate platelet, as anticoagulant when it activates Protein C. This knowledge is used for the pharmacologic control of blood coagulation, so monitoring its activity is reliable indicator of the rate and extent of coagulation. A simple, rapid, sensitive and accurate spectrophotometric method is suggested for the determination of thrombin in pure form and in biological fluids. The utility of someπ-acceptors as 2,3-dichloro-5,6-dicyanobenzoquinone(DDQ), 7,7,8,8-tetracyanoquinodimethane (TCNQ) and tetracyanoethylene (TCNE) for thrombin (as electron donor)determination is described. These π-acceptors give highly coloured complex species that have been spectrophotometrically studied. The optimum experimental conditions for these CT reactions have been studied carefully. Beer’slaw is obeyed over the concentration ranges of 10-130,50-150 and 10-100 μg ml-1 thromb in using DDQ, TCNQ and TCNE reagents, respectively. The percentage recovery amounts to 99.33-100.1% (SD = 0.032-0.075), 99.50-102.5% (SD = 0.016-0.076) and 99.5-101.4% (SD = 0.034-0.088) for four to six experiments. The reagents are utilized for the determination of thrombin in poor platelet plasma of dialysis patients with a percentage recovery amount to 98.76-103.3% (for n = 5). No endogenous compounds were found to interfere. The results obtained applying theπ-acceptors reagents are comparable with those obtained by the official method

Angular Control Charts: A New Perspective for Monitoring Reliability of Multi-State Systems

Control charts, as had been used traditionally for quality monitoring, were applied alternatively to monitor systems' reliability. In other words, they can be applied to detect changes in the failure behavior of systems. Such purpose imposed modifying traditional control charts in addition to developing charts that are more compatible with reliability monitoring. The latter developed category is known as probability limits control charts. The existing reliability monitoring control charts were only dedicated to binary-state systems, and they can't be used to monitor several states simultaneously. Therefore, this paper develops a design of control charts that accommodates multi-state systems, called here as the Angular Control Chart, which represents a new version of the probability limits control charts. This design is able to monitor state transitions simultaneously and individually in addition. Illustrative system examples are implemented to explore the monitoring procedure of the new design and to demonstrate its efficiency, effectiveness, and limitations.Comment: 18 pages; 13 figure

Electrical characterisation of deep level defects in Be-doped AlGaAs grown on (100) and (311)A GaAs substrates by MBE

The growth of high mobility two-dimensional hole gases (2DHGs) using GaAs-GaAlAs heterostructures has been the subject of many investigations. However, despite many efforts hole mobilities in Be-doped structures grown on (100) GaAs substrate remained considerably lower than those obtained by growing on (311)A oriented surface using silicon as p-type dopant. In this study we will report on the properties of hole traps in a set of p-type Be-doped Al0.29Ga0.71As samples grown by molecular beam epitaxy on (100) and (311)A GaAs substrates using deep level transient spectroscopy (DLTS) technique. In addition, the effect of the level of Be-doping concentration on the hole deep traps is investigated. It was observed that with increasing the Be-doping concentration from 1 × 1016 to 1 × 1017 cm-3 the number of detected electrically active defects decreases for samples grown on (311)A substrate, whereas, it increases for (100) orientated samples. The DLTS measurements also reveal that the activation energies of traps detected in (311)A are lower than those in (100). From these findings it is expected that mobilities of 2DHGs in Be-doped GaAs-GaAlAs devices grown on (311)A should be higher than those on (100)

Changes in neuromuscular structure and functions of human colon during ageing are region-dependent

Objective: To determine if human colonic neuromuscular functions decline with increasing age.Design: Looking for non-specific changes in neuromuscular function, a standard burst of electrical field stimulation (EFS) was used to evoke neuronally mediated (cholinergic/nitrergic) contractions/relaxations in ex vivomuscle strips of human ascending and descending colon, aged 35–91 years (macroscopically normal tissue; 239 patients undergoing cancer resection). Then, to understand mechanisms of change, numbers and phenotype of myenteric neurons (30 306 neurons stained with different markers), densities of intramuscular nerve fibres (51 patients in total) and pathways involved in functional changes were systematically investigated (by immunohistochemistry and use of pharmacological tools) in elderly (≥70 years) and adult (35–60 years) groups.Results: With increasing age, EFS was more likely to evoke muscle relaxation in ascending colon instead of contraction (linear regression: n=109, slope 0.49%±0.21%/year, 95% CI ), generally uninfluenced by comorbidity or use of medications. Similar changes were absent in descending colon. In the elderly, overall numbers of myenteric and neuronal nitric oxide synthaseimmunoreactive neurons and intramuscular nerve densities were unchanged in ascending and descending colon, compared with adults. In elderly ascending, not descending, colon numbers of cell bodies exhibiting choline acetyltransferase immunoreactivity increased compared with adults (5.0±0.6 vs 2.4±0.3 neurons/mm myenteric plexus, p=0.04). Cholinergically mediated contractions were smaller in elderly ascending colon compared with adults (2.1±0.4 and 4.1±1.1 g-tension/gtissue during EFS; n=25/14; p=0.04); there were no changes in nitrergic function or in ability of the muscle to contract/relax. Similar changes were absent in descending colon.Conclusion: In ascending not descending colon, ageing impairs cholinergic function

Floods and flood management and its socio-economic impact on Pakistan: A review of the empirical literature

Flood is one of the most damaging natural disasters as the recent floods have shown their serious impact on Pakistan. Flood control and regulation policies are essential to reduce the risks of economic downturn, a threat to human existence, and to sustain the ecology. The severity of flood catastrophe activities represents a constant and severe issue in the world. Floods are rising year by year in severity and duration, causing negative impacts on the social and economic conditions of the nation concerned. While the frequency of floods cannot be avoided, their adverse impacts can be considerably reduced by adopting careful planning and efficient training. This paper reviews the socioeconomic impact of floods, and the existing condition of flood control policies outlines the flood protection problems and discusses opportunities for successful and efficient flood control in Pakistan. The paper also intends to propose several suggestions for efficient and sustainable flood control in Pakistan

Novel intervention to promote COVID-19 protective behaviours among Black and South Asian communities in the UK: protocol for a mixed-methods pilot evaluation

INTRODUCTION: Culturally appropriate interventions to promote COVID-19 health protective measures among Black and South Asian communities in the UK are needed. We aim to carry out a preliminary evaluation of an intervention to reduce risk of COVID-19 comprising a short film and electronic leaflet. METHODS AND ANALYSIS: This mixed methods study comprises (1) a focus group to understand how people from the relevant communities interpret and understand the intervention's messages, (2) a before-and-after questionnaire study examining the extent to which the intervention changes intentions and confidence to carry out COVID-19 protective behaviours and (3) a further qualitative study exploring the views of Black and South Asian people of the intervention and the experiences of health professionals offering the intervention. Participants will be recruited through general practices. Data collection will be carried out in the community. ETHICS AND DISSEMINATION: The study received Health Research Authority approval in June 2021 (Research Ethics Committee Reference 21/LO/0452). All participants provided informed consent. As well as publishing the findings in peer-reviewed journals, we will disseminate the findings through the UK Health Security Agency, NHS England and the Office for Health Improvement and Disparities and ensure culturally appropriate messaging for participants and other members of the target groups

Ex vivo study of human visceral nociceptors.

OBJECTIVE: The development of effective visceral analgesics free of deleterious gut-specific side effects is a priority. We aimed to develop a reproducible methodology to study visceral nociception in human tissue that could aid future target identification and drug evaluation. DESIGN: Electrophysiological (single unit) responses of visceral afferents to mechanical (von Frey hair (VFH) and stretch) and chemical (bradykinin and ATP) stimuli were examined. Thus, serosal afferents (putative nociceptors) were used to investigate the effect of tegaserod, and transient receptor potential channel, vanilloid 4 (TRPV4) modulation on mechanical responses. RESULTS: Two distinct afferent fibre populations, serosal (n=23) and muscular (n=21), were distinguished based on their differences in sensitivity to VFH probing and tissue stretch. Serosal units displayed sensitivity to key algesic mediators, bradykinin (6/14 units tested) and ATP (4/10), consistent with a role as polymodal nociceptors, while muscular afferents are largely insensitive to bradykinin (0/11) and ATP (1/10). Serosal nociceptor mechanosensitivity was attenuated by tegaserod (-20.8±6.9%, n=6, p<0.05), a treatment for IBS, or application of HC067047 (-34.9±10.0%, n=7, p<0.05), a TRPV4 antagonist, highlighting the utility of the preparation to examine the mechanistic action of existing drugs or novel analgesics. Repeated application of bradykinin or ATP produced consistent afferent responses following desensitisation to the first application, demonstrating their utility as test stimuli to evaluate analgesic activity. CONCLUSIONS: Functionally distinct subpopulations of human visceral afferents can be demonstrated and could provide a platform technology to further study nociception in human tissue

Small bowel perforation secondary to intestinal tuberculosis in patient with chronic idiopathic myelofibrosis

Idiopathic myelofibrosis is a clonal hematopoetic stem cell disorder due to a mutation in the signaling regulator gene Janus Kinase 2 (JAK2).The condition is widely treated with Ruxolitinib which is a JAK2 inhibitor along with prednisolone. However, these treatment despite promising has been linked with the risk of opportunistic infections and reactivation of tuberculosis.We reported a patient with chronic idiopathic myelofibrosis who developed small bowel perforations secondary to flare up of gut tuberculosis. The perforation sites were resected and double barrel stoma was created.peer-reviewe

Optoelectronic characterization of CuInGa(S)2 thin films grown by spray pyrolysis for photovoltaic application

[EN] Copper-indium gallium disulfide (CIGS) is a good absorber for photovoltaic application. Thin films of CIGS were prepared by spray pyrolysis on glass substrates in the ambient atmosphere. The films were characterized by different techniques, such as structural, morphological, optical and electrical properties of CIGS films were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), spectrophotometer and Hall effect, respectively. After optimization, the deposited films structure, grain size, and crystallinity became more important with an increase of annealing time at 370 degrees C for 20 min. Transmission electron microscopy (TEM) analysis shows that the interface sheets are well crystallized and the inter planer distance are 0.25 nm, 0.28 nm, and 0.36 nm. The atomic force microscopy (AFM) observation shows that the grain size and roughness can be tolerated by optimizing the annealing time. The strong absorbance and low transmittance were observed for the prepared films with a suitable energy bandgap about 1.46 eV. The Hall effect measurement system examined that CIGS films exhibited optimal electrical properties, resistivity, carrier mobility, and carrier concentration which were determined to be 4.22 x 10(6) omega cm, 6.18 x 10(2) cm(2) V-1 S-1 and 4.22 x 10(6) cm(-3), respectively. The optoelectronic properties of CIGS material recommended being used for the photovoltaic application.Prof. Bouchaib HARTITI, The Senior Associate at ICTP, is very grateful to ICTP for permanent support. Prof. Mohamed Ebn Touhami, Director of the University Center for Analysis, Expertise, Transfer of Technology and Incubation, Kenitra, Morocco, is very grateful to CUA2TI for financial support. Thanks to Doctor Diogo M.F. Santos for the supervision of Amal Bouich's work during her research in CeFEMA research center. 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