Experimental and Theoretical Study on Reverse Osmosis Based Water Desalination

Freshwater availability has dropped due to population growth, inefficient use, climate change, and industrial pollution. Although the reverse osmosis, RO, system is one of the most effective desalination technologies worldwide, spiral wound membranes still need deeper theoretical and experimental investigations for removing salts under low energy consumption. In this study, the performance of a commercial pilot RO plant that utilizes a spiral wound seawater membrane module is experimentally investigated under a wide range of operating parameters. In addition, a Mathematical model is developed based on the solution-diffusion model theory and then solved using an in-house MATLAB algorithm to analyze its performance. The theoretical and experimental results were then compared. The present results revealed that the mathematical model’s predictions were highly consistent with the actual experimental results, achieving an average accuracy of about 98%. The average deviation was 4.0578% when predicting water productivity and just 0.2755% when estimating the salt rejection coefficient. The findings of this study could assist designers in predicting the membrane’s performance and selecting the most advantageous operational parameters for supplying water to the RO system

Experimental and Theoretical Study on Reverse Osmosis Based Water Desalination

Freshwater availability has dropped due to population growth, inefficient use, climate change, and industrial pollution. Although the reverse osmosis, RO, system is one of the most effective desalination technologies worldwide, spiral wound membranes still need deeper theoretical and experimental investigations for removing salts under low energy consumption. In this study, the performance of a commercial pilot RO plant that utilizes a spiral wound seawater membrane module is experimentally investigated under a wide range of operating parameters. In addition, a Mathematical model is developed based on the solution-diffusion model theory and then solved using an in-house MATLAB algorithm to analyze its performance. The theoretical and experimental results were then compared. The present results revealed that the mathematical model’s predictions were highly consistent with the actual experimental results, achieving an average accuracy of about 98%. The average deviation was 4.0578% when predicting water productivity and just 0.2755% when estimating the salt rejection coefficient. The findings of this study could assist designers in predicting the membrane’s performance and selecting the most advantageous operational parameters for supplying water to the RO system

Seasonal Changes in the Occurrence of Listeria Monocytogenes in Duhok Province

Listeria monocytogenes are Gram-positive bacilli cause listeriosis, associated with high rates of hospitalization and mortality. A total of 1362 samples were investigated included 647 clinical samples and 715 from food. This study investigated the differences in the seasonal occurrence of L. monocytogenes in Kurdistan region-Iraq.   L. monocytogeneswas found in 48 samples (3.52%) out of 1362 samples. There were 7/642(1.09%) human clinical samples diagnosed with cold and moderate weather (November, December 2016, and January, February, April 2017). While 41/715(5.73%) of L. monocytogenesisolates were found among food samples, meat samples (n=37) and dairy samples (n=4). A total of 37/476 (7.77%) of the L. monocytogenes isolates in meat samplesweredetected during warm weather (from July through October 2016). In addition, L. monocytogenesin dairy products was found to be by 4/239 (1.68%), were isolated during the moderate season (October, November 2016, and April, May 2017). The study found that the incidence of meat contamination by L. monocytogenesincrease significantly during the warm season in comparison with other seasons. Furthermore, the cases of human Listeriosis caused correlated well with the seasonal levels of L. monocytogenesfound in dairy products. A statistically significant difference in the occurrence of L. monocytogenesisolates and seasons were identified in this study (P value= <0.05)

Pushover Analysis of Existing 4 Storey RC Flat Slab Building

A four-story residential existing reinforced concrete building in the city of Khartoum-Sudan, subjected to seismic hazard ,was analyzed. Plastic hinge is used to represent the failure mode in the beams and columns when the member yields. The pushover analysis was performed on the building using SAP2000 software (Ver.14) and equivalent static method according to UBC 97. The principles of Performance Based Seismic Engineering are used to govern the analysis, where inelastic structural analysis is combined with the seismic hazard to calculate expected seismic performance of a structure. Base shear versus tip displacement curve of the structure, called pushover curve, is an essential outcomes of pushover analysis. The pushover analysis is carried out in both positive and negative x and y directions. Default hinge properties, available in some programs based on the FEMA -356 and Applied Technology Council (ATC-40) guidelines are used for each member. One case study has been chosen for this purpose. The evaluation has proved that the four-story residential building is not seismically safe

Some 3, 5-Diaryl and 1, 3, 5-Triaryl-2-Pyrazoline Derivatives

Abstract: A series of 3,5-diaryl-Δ 2 -pyrazolines (2a-h) were prepared by the reaction of 1,3-diaryl-2-propen-1-ones (1) with hydrazine hydrate and used as precursor for the preparation of 1-acetyl-2-pyrazolines (3a-d). A series of1,3,5-triaryl-2-pyrazolines (6a-h) and (7a-g) were prepared by the reaction of 1,3-diaryl-2-propen-1-ones (1) with phenyl hydrazine and/or 2,4-dinitrophenylhydrazine. Similarly, 3,5-diaryl isoxazoline derivatives (9a,b) were prepared by the 1,3-cyclocondensation of 1,3-diaryl-2-propen-1-ones (1) with hydroxylamine hydro-chloride. Also 1-carbamoyl-, and 1-thiocarbamoyl-2-pyrazoline derivatives (8a-e) and (8f-j) were synthesized. The structures of the new compounds were proved by means of their IR, 1 H-, 13 C-NMR, MS spectroscopic data and microanalysis. All the new compounds were examined for their in vitro antimicrobial activity. Some newly synthesized compounds were examined for their in vitro anticancer activity. In the present investigation, we discuss the structure-activity relationships and biological activities of these compounds

Growth and Yield of Roselle (Hibiscus sabdariffa L) as Influenced by Plant Population in Arid Tropic of Sudan under Rain-fed.

Abstract Growth plant is the result of transfer of solar radiation in to the photosynthetic processes of green leaf and transmission of photosynthates into increased biomass. Recently, many researchers have manipulated plant row-spacing and direction as well as plant populations within the row, to increase crop production through more efficient use of solar energy. A field experiment was conducted in North Kordofan State of Sudan, to investigate the effect of intra -row spacing (10, 20, 30 and 40cm) and planting stand (two and three plants per stand) on yield and yield components of Hibiscus sabdariffa L. The results showed that, plant population had a significant effect on most of the attributes measured. Closer spacing increased the number of branches per plant, days to 50% flowering, days to 95% physiological maturity, number of calyces per plant, calyces yield (g/plant) and decreased final calyces yield (t/ha). Spacing of 20 cm and three plants per stand gave highest calyces yield (t/ha)

Perceived risk of infection and death from COVID-19 among community members of low- and middle-income countries: A cross-sectional study [version 1; peer review: awaiting peer review]

Background: Risk perceptions of coronavirus disease 2019 (COVID-19) are considered important as they impact community health behaviors. The aim of this study was to determine the perceived risk of infection and death due to COVID-19 and to assess the factors associated with such risk perceptions among community members in low- and middle-income countries (LMICs) in Africa, Asia, and South America. Methods: An online cross-sectional study was conducted in 10 LMICs in Africa, Asia, and South America from February to May 2021. A questionnaire was utilized to assess the perceived risk of infection and death from COVID-19 and its plausible determinants. A logistic regression model was used to identify the factors associated with such risk perceptions. Results: A total of 1,646 responses were included in the analysis of the perceived risk of becoming infected and dying from COVID-19. Our data suggested that 36.4% of participants had a high perceived risk of COVID-19 infection, while only 22.4% had a perceived risk of dying from COVID-19. Being a woman, working in healthcare-related sectors, contracting pulmonary disease, knowing people in the immediate social environment who are or have been infected with COVID-19, as well as seeing or reading about individuals infected with COVID-19 on social media or TV were all associated with a higher perceived risk of becoming infected with COVID-19. In addition, being a woman, elderly, having heart disease and pulmonary disease, knowing people in the immediate social environment who are or have been infected with COVID-19, and seeing or reading about individuals infected with COVID-19 on social media or TV had a higher perceived risk of dying from COVID-19. Conclusions: The perceived risk of infection and death due to COVID-19 are relatively low among respondents; this suggests the need to conduct health campaigns to disseminate knowledge and information on the ongoing pandemic

Standard achromatic perimetry, short wavelength automated perimetry, and frequency doubling technology for detection of glaucoma damage

Objective: Reevaluation of the relationship between short wavelength automated perimetry (SWAP), standard achromatic perimetry (SAP), and frequency doubling technology (FDT) in glaucoma and ocular hypertensive patients and in glaucoma suspects. Design: Prospective comparative observational study. Participants: Four age-matched groups were evaluated (42 patients with early to moderate glaucoma, 34 ocular hypertensives, 22 glaucoma suspects, and 25 normal controls) using SAP, SWAP, and FDT. Intervention: All participants underwent full clinical ophthalmologic evaluation followed by SWAP, SAP, and FDT perimetry within a period of not more than 3 months. Mean defect (MID), pattern standard deviation (PSD), visual field (VF) indices, and the percentage of depressed visual field points with P value <5% and <1% in the pattern deviation plot were evaluated. Main Outcome Measures: For each of the four study groups, the MID, PSD, and the percentage of abnormal points significantly depressed <5% and <1% were compared for the three VF testing modalities. Results: In the glaucoma group, the mean percentage of the total number of abnormal points in SWAP was significantly less than abnormal points in SAP and FDT, both for 5% (P values were 0.0001 and 0.0001, respectively) and 1% (P values were 0.0001 and 0.0001, respectively). The same applied to the ocular hypertensives group. However, in the suspects group, no significant difference was detected. In normal controls, the abnormal points in SWAP were significantly lower than those in SAP for 5% (P value was 0.01) and 1% (P value was 0.05). FDT detected significantly larger defects (percentage of points <5%) than SAP in ocular hypertensives and suspects (P values were 0.01 and 0.004, respectively). Conclusions: SWAP in its existing condition is markedly less efficient than either SAP or FDT in detecting VF defects, especially in glaucoma patients and ocular hypertensives (defects detected with SWAP are less than both SAP and FDT). Defects detected with FDT are equivalent to SAP and sometimes larger, especially in ocular hypertensives and glaucoma suspects; this makes it a useful tool for picking up early glaucomatous defects in populations at risk. Ophthalmology 2002;109:444-454 (C) 2002 by the American Academy of Ophthalmolog

Retinal nerve fiber layer analysis: Relationship between optical coherence tomography and red-free photography

PURPOSE: Comparison of retinal nerve fiber layer (RNFL) thickness measurements using optical coherence tomography (OCT) to the clinical standard red-free photography (evaluated semiquantitatively), in relation to functional visual field damage in primary open-angle glaucoma (POAG) patients, ocular hypertensives, and POAG suspects. METHODS: Concurrent, cross-sectional study. In four age matched groups (42 patients with early to moderate POAG, 34 ocular hypertensives, 22 POAG suspects, and 25 normal controls), RNFL was assessed with OCT, standardized red-free photographic scoring method and standard achromatic perimetry. RESULTS: OCT RNFL thickness decreases with in creased RNFL damage (detected with red,free photography). The global average OCT RNFL thickness correlated significantly with the photographic total RNFL score (r = .650, P = .0001). Both OCT and photographic scoring system were able to find significantly thinner RNFL in the glaucoma group as compared with normals (P = .0001 for both), ocular hypertensives (P = .0001 for both), and suspects (P = .0001 for both). However, neither OCT nor photography could significantly differentiate between ocular hypertensives, suspects, and normals. Both OCT and photography were significantly correlated with VF loss. For the percentage of VF points depressed <5%, the correlation was highest for OCT (r = -0.615 for OCT and r = -0.476 for photography). OCT had a higher diagnostic accuracy than photography (86% and 77%, respectively). CONCLUSION: For RNFL thickness measurements, the presence of high correlations between OCT, photographic scores, and functional visual field loss suggest the validity of OCT measurements. The higher diagnostic accuracy of OCT RNFL measurements suggests its potential advantage for detection of early cases of glaucoma. (Am J Ophthalmol 2002;133:187-195. (C) 2002 by Elsevier Science Inc. All rights reserved.