Adsorption of benzene and naphthalene to modified montmorillonite

This study aims to characterize the adsorption pattern of benzene and naphthalene on montmorillonite modified with hexadecyltrimethylammonium (HDTMA), tetramethylammonium (TMA), tetraethylammonium (TEA), tetrabutylammonium (TBA) or benzyltrimethylammonium (BTMA). Adsorption isotherms of benzene and naphthalene from water followed Langmuir and Freundlich models respectively. The Langmuir form of the isotherms suggests that benzene and naphthalene adsorbed to the surfaces as a monolayer. Binding coefficient of naphthalene increased as the molecular weight of the pre-adsorbed surfactant increased. Adsorption of benzene and naphthalene follows the sequence: montmorillonite-benzyltrimethylammonium> montmorillonite-hexadecyltrimethylammonium> montmorillonite-tetrabutylammonium> montmorillonite-tetraethylammonium> montmorillonite-tetramethylammonium. The results indicate that using those complexes can be useful in removing pollutants from water

Bioremediation of diuron in soil environment: influence of cyanobacterial mat

Diuron is a herbicide widely used in the Middle East; its field application creates many environmental problems. This study investigated the bioremediation of Diuron in soil environment by Cyanobacterial mats collected from Gaza Wadi. Various concentrations of Diuron were injected in water saturated soil samples pre-treated with Cyanobacterial mat for several periods. Percent growth of Jews mallow as a test plant was taken as indicator of biodegradation of Diuron. Results showed that Diuron was degraded in soil and degradation was more pronounced when Diuron was incubated with Cyanobacterial in the irrigation water. Larger applied rate of Cyanobacterial mat did not affect the biodegradation of Diuron. These encouraging results suggest that application of Cyanobacterial mat could be a suitable method to remediate soil pollution

PROPERTIES OF CONCRETE CONTAINING CRUSHED LIMESTONE AS TOTAL REPLACEMENT OF NATURAL SAND AND RECYCLED ENGINE OIL

The rapid growth in the construction industry at the global level has made concrete the most widely used construction material throughout the world. Accordingly, the consumption of natural sand which is one the main raw material constituent of concrete is continuously growing. The demand for river sand is highly increasing due to its scarcity in the market. Manufactured sand produced by crushed rock is being considered as an appropriate alternative to replace river sand in concrete. In recent years, there is a growing interest in the use of crushed sand obtained from limestone quarries in some countries where river sand is not widely available”. The objective of this study is to investigate the effect of total replacement of the natural sand by fine aggregates obtained from crushed limestone. However, it needs more research on the crushed stone fine aggregates to reveal its engineering properties prior to utilization in concrete. Another objective of this study is to study the effect of using the waste engine oil as partial replacement of water reducing admixture. The use of waste engine oil in concrete is beneficial for the environment. It is to be noted that some countries are recycling this used oil but others are throwing it in the sea and harming the marine life. In this paper, different combinations and grading of fine lime stone and coarse aggregates were tried in order to attain the optimal proportion that provide an acceptable concrete performance in terms of workability and compressive strength. Also, different percentages of admixture replacement ranging from zero to one hundred percent of the used engine oil were tried in the selected optimal mixture proportion. The final selected proportion using engine oil and crushed limestone could be considered as an economical solution and friendly environmental concrete product

Partial Ureteropelvic Junction Disruption after Blunt Trauma: Case Report

Partial ureteropelvic junction disruption as a result of blunt trauma is rare and frequently missed by the initial trauma evaluation. Delays in diagnosis have also been associated with significant morbidity. A high index of suspicion should lead to appropriate investigations, and the management will be determined by the severity of the disruption. We present herein a 24-year-old man who was admitted to the Emergency Room with multiple organ injuries caused by a severe blunt trauma. Emergency celiotomy was performed for massive hemoperitoneum and shattered spleen which led to splenectomy. The diagnosis of partial UPJ disruption was missed preoperatively and suspected in CT scan after appearance of flank tender mass. Confirmation was obtained in retrograde ureteropyelography and treated conservatively with indwelling ureteral stent. We present herein an extensive review of the literature to examine the current status of this entity and to determine if improvements could be made in the diagnosis and treatment

Prevalence and Configuration of the Second Mesiobuccal Canal in the Permanent Maxillary First Molar in Jordanian Population Sample

Introduction: Missing a root canal during endodontic treatment implicates the persistence of microbial infection within the root canal system. This study aims to evaluate the incidence and morphology of the second mesiobuccal canal in the maxillary first molars in the Jordanian population. Methods and Materials: Consecutive cone-beam computed tomography (CBCT) scans taken at Jordan University Hospital were assessed in this retrospective study. A total of 200 scans that were examined, 111 were included in this study. The scans that were included had to have a full view of the maxilla with at least one permanent maxillary first molar. The following data were collected: the presence of a second mesiobuccal canal, the configuration of the mesiobuccal canals, the status of the apical area and the mesiobuccal inter-orifice distance, if applicable. The prevalence and morphology of the second mesiobuccal canal was determined and its association with biological sex and right or left sidedness was measured using the Chi-Square test. Results: The prevalence of the second mesiobuccal canal in our sample of the Jordanian population was 87%, with the most common canal configuration being Vertucci type II. The average inter-orifice distance between first and second mesiobuccal canals was 1.9 ± 0.4 mm. Conclusion: This retrospective study is the first in Jordan to document the prevalence of the second mesiobuccal canal using CBCT, and it shows that the vast majority of teeth have a second mesiobuccal canal. The proper location and negotiation of this canal is of dire importance for endodontic therapy.&nbsp

Power Quality and System Stability Impact of Large-Scale Distributed Generation on the Distribution Network: Case Study of 60 MW Derna Wind Farm

Wind energy (WE) has become one of the most promising and developed forms of renewable energy source due to its efficiency and the availability of different capacities according to the loading requirements. The integration of wind turbines in the Libyan network has become an indispensable choice due to Libya’s distinguished location and for the Libyan National Initiative. Despite the numerous benefits of WE, the penetration of WE sources in the distribution network has some negative impacts related to the quality and reliability of the electric power supplied to the network. Owing to, the intermittent nature of these sources and electronic circuits needed to regulate the extracted power to comply with the grid requirements. In this chapter, implementation of the eastern Libyan network in NEPLAN and MATLAB/SIMULINK packages are carried out to investigate and analyze the significance of wind farm penetration in the medium voltage level of Libyan Distribution Network. A 60 MVA wind farm system has been connected to the Libyan distribution network according to the Libyan National Initiative. Different penetration scenarios are simulated to testify the technical aspects of integrating WE on the distribution level

Anévrysme et Pseudo-anévrysme du ventricule gauche

La gravité de l’infarctus du myocarde réside dans ses complications. Certainement, on avait une importante réduction dans leurs incidences grâce  à  l’amélioration de la prise en charge médicale et l’avènement des méthodes de reperfusion précoce, mais il persiste un taux considérable de complications qui posent un problème diagnostic mais surtout thérapeutique. Parmi eux, il existe l’anévrysme et le pseudo-anévrysme du ventricule gauche. Ces deux complications relativement rares sont souvent méconnues, d’où l’intérêt d’en connaître les modalités de prise en charge diagnostique et thérapeutiques

Eliciting policymakers' and stakeholders' opinions to help shape health system research priorities in the Middle East and North Africa region

Evidence-informed decisions can strengthen health systems. Literature suggests that engaging policymakers and other stakeholders in research priority-setting exercises increases the likelihood of the utilization of research evidence by policymakers. To our knowledge, there has been no previous priority-setting exercise in health policy and systems research in countries of the Middle East and North Africa (MENA) region. This paper presents the results of a recent research priority-setting exercise that identified regional policy concerns and research priorities related to health financing, human resources and the non-state sector, based on stakeholders in nine low and middle income countries (LMICs) of the MENA region. The countries included in this study were Algeria, Egypt, Jordan, Lebanon, Morocco, Palestine, Syria, Tunisia and Yemen. This multi-phased study used a combination of qualitative and quantitative research techniques. The overall approach was guided by the listening priority-setting approach, adapted slightly to accommodate the context of the nine countries. The study was conducted in four key phases: preparatory work, country-specific work, data analysis and synthesis, and validation and ranking. The study identified the top five policy-relevant health systems research priorities for each of the three thematic areas for the next 3-5 years. Study findings can help inform and direct future plans to generate, disseminate and use research evidence for LMICs in the MENA region. Our study process and results could help reduce the great chasm between the policy and research worlds in the MENA region. It is hoped that funding agencies and countries will support and align financial and human resources towards addressing the research priorities that have been identifie

Very high titanium content mesoporous silicas

Titanium content in mesoporous titanosilicate catalysts has been modulated up to a minimum Si/Ti value of 1.9 by using complexing agents able to coordinate both Si and Ti atoms and harmonize the reactivity of the resulting precursors avoiding subsequent phase segregation and leading to chemically very homogeneous materials.El Haskouri, Jamal, [email protected] ; Beltran Porter, Aurelio, [email protected] ; Beltran Porter, Daniel, [email protected] ; Amoros del Toro, Pedro Jose, [email protected]

Study of State Estimation Using Weighted Least Squares Method

Power state estimation constitutes the core of the on-line security analysis function. The challenge number one of a state estimator is to provide the optimal estimates of system state with minimum of measurement data. This paper describes weighted least squares state estimation method and investigates how the efficiency of WLS state estimation changes according to 4 parameters: number of measurements, measurement type, measurement weight and level of noise. Different simulation cases are tested on 3-bus system and IEEE 14-bus system. The results show that accurate estimates of system state can be obtained with minimum of measurement data on condition to choose a good combination of accurate measurements with a minimum of voltage measurements and power injection measurements and these data should be properly distributed throughout the system. For best results, the two factors (weight and noise) must be combined to obtain the best estimation. Indeed, the most accurate measurements (lower level of noise) should have greater weight compared to bad measurements (higher level of noise), specially voltage measurements due to their big impact