Liquid-liquid extraction in a pilot scale rotating disc contactor

A study of the hydrodynamics and mass transfer characteristics of a liquid-liquid extraction process in a 450 mm diameter, 4.30 m high Rotating Disc Contactor (R.D.C.) has been undertaken. The literature relating to this type of extractor and the relevant phenomena, such as droplet break-up and coalescence, drop mass transfer and axial mixing has been revjewed. Experiments were performed using the system C1airsol-350-acetone-water and the effects of drop size, drop size-distribution and dispersed phase hold-up on the performance of the R.D.C. established. The results obtained for the two-phase system C1airso1-water have been compared with published correlations: since most of these correlations are based on data obtained from laboratory scale R.D.C.'s, a wide divergence was found. The hydrodynamics data from this study have therefore been correlated to predict the drop size and the dispersed phase hold-up and agreement has been obtained with the experimental data to within +8% for the drop size and +9% for the dispersed phase hold-up. The correlations obtained were modified to include terms involving column dimensions and the data have been correlated with the results obtained from this study together with published data; agreement was generally within +17% for drop size and within +14% for the dispersed phase hold-up. The experimental drop size distributions obtained were in excellent agreement with the upper limit log-normal distributions which should therefore be used in preference to other distribution functions. In the calculation of the overall experimental mass transfer coefficient the mean driving force was determined from the concentration profile along the column using Simpson's Rule and a novel method was developed to calculate the overall theoretical mass transfer coefficient Kca1, involving the drop size distribution diagram to determine the volume percentage of stagnant, circulating and oscillating drops in the sample population. Individual mass transfer coefficients were determined for the corresponding droplet state using different single drop mass transfer models. Kca1 was then calculated as the fractional sum of these individual coefficients and their proportions in the drop sample population. Very good agreement was found between the experimental and theoretical overall mass transfer coefficients. Drop sizes under mass transfer conditions were strongly dependant upon the direction of mass transfer. Drop Sizes in the absence of mass transfer were generally larger than those with solute transfer from the continuous to the dispersed phase, but smaller than those with solute transfer in the opposite direction at corresponding phase flowrates and rotor speed. Under similar operating conditions hold-up was also affected by mass transfer; it was higher when solute transfered from the continuous to the dispersed phase and lower when direction was reversed compared with non-mass transfer operation

Efficacy of diphtheria and tetanus vaccination in Gaza, Palestine.

This study evaluated the effectiveness and usefulness of vaccination against diphtheria and tetanus in different age groups in Gaza, Palestine. Blood samples were collected from 180 children aged< 12 years, 90 males and 90 females. Using ELISA methods, the efficacy of vaccination was estimated at 87.8% for diphtheria and 98.3% for tetanus. Mean serum titres varied significantly by age group: for diphtheria 0.24 IU/mL at age 2–4 years, 0.63 IU/mL at 7–8 years and 0.46 IU/mL at 11–12 years, and for tetanus 1.01 IU/mL, 2.63 IU/mL and 1.20 IU/mL respectively. The relatively low antibody titres, especially for diphtheria, suggest the need for a booster dose

On the Kinetic Energy Density Functional: The Limit of the Density Derivative Order

Within ``orbital-free'' density functional theory, it is essential to develop general kinetic energy density (KED), denoted as $t(\mathbf{r})$. This is usually done by empirical corrections and enhancements, gradient expansions, machine learning, or axiomatic approaches to find forms that satisfy physical necessities. In all cases, it is crucial to determine the largest spatial density derivative order, $m$ in, $t(\mathbf{r})$. There have been many efforts to do so, but none have proven general or conclusive and there is no clear guide on how to set $m$. In this work, we found that, by imposing KED finitude, $m=D+1$ for systems of dimension $D$. This is consistent with observations and provides a needed guide for systematically developing more accurate KEDs

Issues Concerning the Adoption and Usage of Electronic Medical Records in Ministry of Health Hospitals in Saudi Arabia

Abstract Background:There is a lack of research with regard to understanding the factors that motivate hospitals to proceed with implementing Electronic Medical Record Systems (EMR). The Health Information Management and System Society (HIMSS) outlines eight levels of EMR implementation from 0(no implementation) to 7(full use and implementation of the system). Some hospitals proceed to implement EMR and achieve a high level of implementation, while others stop at a certain level of EMR implementation or may even regress to lower levels. Aims and Methods: This research aimed to develop a framework to understand the motivational and de-motivational factors for proceeding with EMR implementationto uncover which hospitals have implemented EMR, to which levels, and how hospitals perceive EMR. In order to accomplish this,a mixed method design was adopted including a survey and case studies of a sample of hospitals in Eastern Saudi Arabia. The three case study sites were: a large hospital located in the capital city, a medium hospital located in a town, and a small hospital located in an isolated rural area. Results: The study found that 3 out of 29 hospitals in the area had implemented EMR. Contrary to expectations, the largest hospital located in the central city had regressed from level four of EMR implementation to level one, whereas the smallest hospital located in anisolated rural location achieved the highest EMR level. It was found that there were common factors that affected all the case study sites, whileother factors varied among them. Shared factors motivating sites to adopt EMR included a desire to escape from the manual system, whereas shared de-motivational factors included funding and technical problems. As these factors were common across sites at different levels of implementation, it is suggested that they do not sufficiently explain the variance in implementation level. It is argued that factors which varied between sites, however, may shed more light on the main motivators for implementation. For example, although there were technical problems across the sites,the way these technical problems were treated made the difference in terms of the success of the implementation. Additionally, top management commitment, users’ involvement in the EMR development and other factors varying between sites appeared to make the difference in the implementation’s success. Conclusion:The study concluded that all these common and varied factors affectedstaff attitudes toward the system. However, the site-related factors were perceived to be the main driver for the variance in the implementations. Since all site-related factors are controllable by top management, it is recommended that EMR implementation should be managed and supervised by a committee consisting of representatives from among clinical staff and IT staff. Based on this research, it is believed that such a committee is necessary for proceeding with an EMR implementation. However, there is no empirical evidence from this research about that. Therefore, it is advised that future research should find the rules, authorities and compositions of such committees that would make the committee effective

Response of Masonry Walls to Blast Loading: a Discrete Element Analysis

Civil Engineerin

A STRATIGRAPHIC AND PETROPHYSICAL STUDY OF IN-SITU GEOTHERMAL RESERVOIR QUALITY OF THE CAMBRO-ORDOVICIAN STRATA IN THE SUBSURFACE AT CORNELL UNIVERSITY, ITHACA, NEW YORK

Geothermal energy is an attractive energy source which may significantly offset fossil fuels because of its potential to produce sustainable, widespread, and affordable heat. Cornell University is exploring the subsurface at its Ithaca, New York campus to access the naturally hot deep rocks and produce geothermal fluids for direct use as a thermal source with which to heat campus buildings. A reconnaissance fairway analysis of the geothermal potential of the Appalachian Basin revealed that rocks with suitable natural permeability and heat for geothermal reservoirs are likely to be at 2.3 - 3 km depth. This study investigates the in-situ geological properties and geothermal reservoir potential of the Cambro-Ordovician limestones, dolostones and sandstones underlying the Knox Unconformity at ~2.3 km to 2.8 km depth in Ithaca, New York. This new evaluation is based on repurposing geophysical well logs, drill cuttings and core reports, supplemented by new cuttings analyses, from 78 pre-existing hydrocarbon industry boreholes in central and western New York. Gamma ray, neutron porosity hydrogen index, density and photoelectric factor logs are utilized to derive estimates of the lithologies and porosity of the Cambro-Ordovician strata. Coupled with the logs are cuttings reports and analyses for the interpolation of depths and thickness through the construction of cross-sections and isopach maps. Three intervals of strata are identified as potential reservoirs: the zone at which the basal Ordovician Little Falls Formation limestone or dolostone is interbedded with the upper Galway Formation sandstone known as the Rose Run member in New York; the interbedded sand and dolomite beds of the Galway Formation informally labeled in this study as the Yellowjacket member in New York; and the feldspathic sandstones of the basal Ausable member of the Potsdam Formation. These occur at depths below Ithaca of roughly 2.55 km, 2.7 km and 2.8 km +/ 0.2 km, respectively

Assessment of Readiness of Newly Graduated Health Professionals to Communicate with Patients in Duhok, Kurdistan Region, Iraq

Communication Skills (CS) are essential to health workforce to conduct effective professional-patient interaction. In Iraq, majority of newly graduated health professionals are engaged in provision of direct health services. However, undergraduate curricula preparing these professionals include no distinct component to train them on CS. This study aims at assessing the status of CS among Health Professions Education (HPE) graduates of University of Duhok (UoD) and estimating the perception of their patients toward those skills. This cross-sectional study was conducted in 2014. Data on communication skills was obtained, from samples of different health professionals which included: medical doctors (junior residents, nurses, dentists and pharmacists) who recently graduated from different colleges at the UoD. Also, data from was obtained, their patients, to assess their satisfaction of the professionals’ CS. For assessing core CS, a specially designed checklist was adopted from Calgary-Cambridge Guide. Also, senior clinicians were asked on CS performed by their junior residents. Results show that 88% of the senior academic staff regarded CS as “highly essential” and 66% of them were not satisfied with interns’ conduct and suggested that CS should clearly be included in the medical curricula. The basic CS were perceived by patients as either not practiced or wrongly practiced. Patients were unsatisfied with the CS of their attending HPs during observed consultation sessions. The study shows obvious lack of CS among HPE graduates of UoD with patients’ dissatisfaction of their CSs. It seems legitimate to propose that relevant training elements to be designed and incorporated within training modules are needed to realize as a core element of the curriculum of all HPE colleges at the UoD. Keywords: Communication, skills, perception, graduates, Kurdistan-Iraq. DOI: 10.7176/JHMN/73-02 Publication date: April 30th 202

Discrete Logarithm Factory

The Number Field Sieve and its variants are the best algorithms to solve the discrete logarithm problem in finite fields. The Factory variant accelerates the computation when several prime fields are targeted. This article adapts the Factory variant to non-prime finite fields of medium and large characteristic. We combine this idea with two other variants of NFS, namely the tower and special variant. This combination leads to improvements in the asymptotic complexity. Besides, we lay out estimates of the practicality of this method for 1024-bit targets and extension degree $6$

PCR in Comparison with Culture Methods for The Diagnosis of Candida albicans Responsible for Candidemia in Leukemic Patients

Background: Currently, candidemia infections represent an increasing cause of morbidity and mortality in seriously ill hospitalized patients. Because the accurate diagnosis of candidiasis remains difficult, fast and reliable assay for characterization of fungal pathogens is critical for the early initiation of adequate antifungal therapy and/or for introduction of preventive measures. Objective: To detect candidemia in leukemic patients by molecular methods in comparing with golden standard method (culture method). Materials and methods: A total of 60 leukemic patients were included in this study. Clinical type and other demographic data were recorded. Blood samples were taken from each patient, culture; germ tube formation and carbohydrate fermentation were done for each sample. DNA extraction and polymerase chain reaction (PCR) were used for detection of Candida albicansin cultured bottles. This study was conducted on leukemic patients admitted to four different hospitals in Baghdad city from September 2010 to March 2011.  Sixty patients suffering from acute lymphoid (ALL) and myeloid (AML) leukemia were included in this study. The age of patients were ranging between 3-46 years old. Twenty five apparently healthy individuals were enrolled in this study as control group. Three milliliters of blood were collected from each patient; 1.5 ml was inoculated in 20 ml Brain heart infusion broth (Cruikshank. 1975). The rest of blood (1.5ml) was stored in -20ᴼC for further analysis. Blood cultures were incubated at 37°C for 10 days, and examined daily for growth. DNA purification kit was purchased from QIAGENE®Company. This method was used for the purification of genomic DNA from fresh or frozen samples of 1 ml overnight yeast cultures by using the GentraPuregene Yeast/Bact. Kit. PCR was performed to detect Candida albicans species through the amplification of specific gene (αINT1) Results: Only one positive culture result out of 60 samples was obtained for Candida sp., (1.7%).  PCR results showed that there were only three out of sixty were positive for C. albicans (5%). In this study we obtained only one positive sample according to culture, while three samples only gave positive results according to PCR method. These results suggest that molecular analysis of candidemia is more sensitive and less time consuming than culture and other conventional methods. Conclusions: we concluded the following: The rate of candidemia was 1.7% among leukemic patients, according to culture results, only 5% of blood cultures was positive according to PCR. Results showed 100% sensitivity and 96.6% specificity and it is rapid, easy, reliable and also applicable in clinical laboratory for identification of medically important Candida sp

VERTICAL SUBSURFACE FLOW AND FREE SURFACE FLOW CONSTRUCTED WETLANDS FOR SUSTAINABLE POWER GENERATION AND REAL WASTEWATER SELECTIVE POLLUTANTS REMOVAL

A vertical subsurface flow constructed wetland (VSSFCW) and a free surface flow constructed wetland (FSFCW) were set for the objective of comparison the performance of two systems in order to make a decision of the better one for future installation of wastewater treatment system and power generation. Both of the constructed wetlands were planted with Cyperus Alternifolius. During the observation period (19 days or 456 hours), environmental conditions such as pH, temperature, total chemical oxygen demand (COD), phosphate (PO4), nitrate (NO3), total suspended solids (TSS), total dissolved solids (TDS), Pb, Cu, and Cd removal efficiencies of the systems were determined. According to the results, final removal efficiencies for the VSSF and FWSF, respectively, were: COD (94.3% and 94.3%), PO4 (84.3% and 75.3%), NO3 (100% and 100%), TSS (96.8% and 85.6%), Pb (65.8% and 81.4%), Cu (more than 94.7% and 89.4%), Cd (85.7% and 88%). The treatment performances of the VSSF were better than that of the FWSF with regard to the removal of suspended solids and nutrients. In FWSF systems, electricity generation performed better than VSSF of 31.4 mV especially with batch system during one wastewater feed is loaded among all of the nineteen days with maximum voltage of 33.7 mV and decreased gradually as oxygen depletion in cathode chamber and less metabolism processes have occurred