636 research outputs found
Experimental (FT-IR and FT-Raman spectra) and Theoretical (Ab initio/HF, DFT/B3LYP) Study of 2-Amino-5-Chloropyridine and 2-Amino-6-Chloropyridine
The Fourier transform infrared (FT-IR) and FT-Raman spectra of 2-amino-5-chloropyridine (2A5CP) and 2-amino-6-chloropyridine (2A6CP) have been recorded in the regions 4000–400 cm-1 and 4000–100 cm-1, respectively. The observed FT-IR and FT-Raman data, a complete vibrational assignment and analysis of the fundamental modes of the compounds were carried out. All the geometrical parameters have been calculated by HF and DFT (B3LYP) methods with 6-311++G (d, p) basis set. The vibrational wavenumbers, IR intensities and Raman activities are calculated at the same theory levels used in geometry optimization. The calculated frequencies are scaled and compared with experimental values. The scaled B3LYP/6-311++G(d,p) results show the best agreement with the experimental values. The calculated HOMO–LUMO energies show that charge transfer occurs in the molecules. Keywords: FT-IR, FT-Raman, ab initio, DFT, 2-amino-5-chloropyridine, 2-amino-6-chloropyridine
DOUBLE PERFORATED IMPINGEMENT PLATE (DPIP) IN SHELL-AND-TUBE HEAT EXCHANGER
This paper presents a solution to a chronic problem causing repeated tube failure at shell-and-tube heat exchangers. The problem is related to fouling process on tubes surface which accumulates downstream the impingement plate at exchanger inlet nozzle within the first tube rows due to low velocity and vortices production. In fouling services, the suspended deposits, fouling, accumulates on tubes surface downstream the impingement plate causing under-deposit corrosion and raising tubes surface temperature due to lack of cooling accelerating fouling process. Under fouling corrosion attacks tubes and causes repeated tube failure costing a lot of money in terms of material, maintenance and production losses. Normal practice of extending tubes life and delaying their failure is to upgrade the tubes metallurgy. So this paper objective is to present an economical solution option through modifying the impingement plate in shell-and-tube heat exchangers where impingement plate is recommended by Tubular Exchanger Manufacturers Association, TEMA. The impingement modification is to replace the solid conventional impingement plate with double spaced plates having offset holes, called Double Perforated Impingement Plate (DPIP). The objective of this work can be met through simulate and compare shell side inlet flow distribution around the conventional and modified impingement plate, DPIP, and insuring of enhancing the flow pattern distribution at the area behind impingement plate. Since experimental work in flow investigation can be time consuming and costly, computational fluid dynamics, CFD, fluent software was implemented as a cost effective helpful tool to conduct the simulation and comparison purpose. The modified impingement plate, DPIP, will destroy vortices created behind the conventional plate retarding fouling accumulation principal. DPIP will enhance shell side flow distribution downstream the impingement plate and stop fouling accumulation on the tubes to prevent under-deposit corrosion
Early detection of diabetic in emergency sittings: A narrative review
Diabetes mellitus (DM) is a chronic metabolic disorder can lead to life-threatening emergencies,Diabetes mellitus characterized by hyperglycemia due to defective insulin secretion, insulin action, or both and Early detection and management of diabetes are crucial to prevent complications such as cardiovascular disease, neuropathy, retinopathy, and nephropathy, which contribute significantly to morbidity and mortality, Common Diabetic Emergencies Diabetic Ketoacidosis (DKA) like Insulin deficiency, hyperglycemia, ketosis and acidosis,Hyperosmolar Hyperglycemic State (HHS) like Severe hyperglycemia and dehydration,Hypoglycemia that are Imbalance of insulin, food intake, and activity levels
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This narrative review aims to explore the importance, challenges, and strategies for early detection of diabetes in emergency setting
The Impact of Property Management on the Value of Residential Product in Saudi Arabia
This paper discusses the impact of property management in maintaining the value of residential product in Saudi Arabia. The paper reviewed a comparison of two property models: the first is managed by the property management system, and the second is managed by the owner only. In addition, the field questionnaire was used and distributed to a sample of the study community consisting of 125 real estate management institutions and real estate office in Riyadh. The results of the analysis indicate that property management contributes to raising the quality of the residential product and maintaining its market value. The residential product which managed by the property management system loses 10% of its value after 5 years. On the other hand, the product that managed by the owner loses more than 50% of its real value after 5 years. The paper proposes to strengthen cooperation between governmental and private institutions to establish a Real Estate Data Center (REDC) for the classification of residential properties subject to the criteria of management, quality and economic cost
Fear of the Unknown among Normal People, People with Psychological Disorders, and People with Organic Disorders in the Light of Some Demographic Variables
The present paper aimed to determine the fear of the unknown among normal people, people with psychological disorders, and people with organic disorders in the light of some demographic variables. The authors adopted the descriptive-comparative method and developed and applied a three-domain questionnaire to a randomly selected sample of (942) participants. The results showed that the people with psychological disorders suffer from fear of the unknown more than normal people and people with organic disorders at a significance level of (0.05). There were no statistically significant differences between the different categories of psychological disorders (including generalized anxiety disorder, depression, panic attacks, post-traumatic stress disorder, obsessive-compulsive disorder, and phobia) in contrast with the organic diseases, in which cardiac and respiratory diseases were at a greater risk of being afraid of the unknown more than those with diabetes, blood pressure, and thyroid. The paper recommends conducting further studies on the concept of fear of the unknown in the Arab countries and adopting fear of the unknown as a psychological intervention for people with psychological disorders and people with cardiac and respiratory diseases
Evaluation of Maternal Polyunsaturated Fatty Acid Status and Its Association with Birth Outcomes
The present study examines the potential role of the Maternal Polyunsaturated Fatty Acid profile in fetal growth by investigating the association between maternal concentrations of these fatty acids in the gestation stage and birth outcome measures (birth weight, birth length, and head circumference at birth). The study covered (255) women with a mean age of 29.22 ± 5.29 years. Half of them had a Bachelor’s degree or higher, and most of them were unemployed. The author used a questionnaire for data collection. The level of fatty acids was not correlated with pregnancy outcomes such as weight, height, and head circumference. A significant positive correlation between total MUFAs and gestational age was established. There was a positive correlation between the level of total n-3 PUFA and gestational weight gain. There was also a positive correlation between nutritional knowledge and the amount of fish consumed during pregnancy. However, no correlation was found between the consumption of fish and pregnancy outcomes. This study has demonstrated preliminary results regarding the level of polyunsaturated fatty acids in pregnant women and pregnancy outcomes that can help evaluate the current or future pregnancy preventative programs when planning reproductive health programs
Evaluation of Maternal Polyunsaturated Fatty Acid Status and Its Association with Birth Outcomes
The present study examines the potential role of the Maternal Polyunsaturated Fatty Acid profile in fetal growth by investigating the association between maternal concentrations of these fatty acids in the gestation stage and birth outcome measures (birth weight, birth length, and head circumference at birth). The study covered (255) women with a mean age of 29.22 ± 5.29 years. Half of them had a Bachelor’s degree or higher, and most of them were unemployed. The author used a questionnaire for data collection. The level of fatty acids was not correlated with pregnancy outcomes such as weight, height, and head circumference. A significant positive correlation between total MUFAs and gestational age was established. There was a positive correlation between the level of total n-3 PUFA and gestational weight gain. There was also a positive correlation between nutritional knowledge and the amount of fish consumed during pregnancy. However, no correlation was found between the consumption of fish and pregnancy outcomes. This study has demonstrated preliminary results regarding the level of polyunsaturated fatty acids in pregnant women and pregnancy outcomes that can help evaluate the current or future pregnancy preventative programs when planning reproductive health programs
Using Orthogonal Locality Preserving Projections to Find Dominant Features for Classifying Retinal Blood Vessels
Automatically classifying retinal blood vessels appearing in fundus camera imaging into arterioles and venules can be problematic due to variations between people as well as in image quality, contrast and brightness. Using the most dominant features for retinal vessel types in each image rather than predefining the set of characteristic features prior to classification may achieve better performance. In this paper, we present a novel approach to classifying retinal vessels extracted from fundus camera images which combines an Orthogonal Locality Preserving Projections for feature extraction and a Gaussian Mixture Model with Expectation-Maximization unsupervised classifier. The classification rate with 47 features (the largest dimension tested) using OLPP on our own ORCADES dataset and the publicly available DRIVE dataset was 90.56% and 86.7% respectively
Correlates of physical activity and sitting time in adults with type 2 diabetes attending primary health care in Oman
Abstract Background Despite evidence of the benefits of physical activity in the management of type 2 diabetes, it is poorly addressed in diabetes care. This study aimed to identify the prevalence and correlates of meeting ≥600MET-min/wk. (150 min/wk) of physical activity and sitting time in adults with type 2 diabetes in Oman. Approaches to encourage physical activity in diabetes care were explored. Methods A cross-sectional study using the Global Physical Activity Questionnaire was conducted in 17 randomly selected primary health centres in Muscat. Clinical data including co-morbidities were extracted from the health information system. Questions on physical activity preferences and approaches were included. Patients were approached if they were ≥18 years, and had been registered in the diabetes clinic for >2 years. Results The questionnaire was completed by 305 people (females 57% and males 43%). Mean age (SD) was 57 (10.8) years and mean BMI (SD) was 31.0 (6.0) kg/m2. Duration of diabetes ranged from 2 to 25 (mean 7.6) years. Hypertension (71%) and dyslipidaemia (62%) were common comorbidities. Most (58.4%) had an HbA1c ≥7% indicating poor glycaemic control (55% in males vs 61% in females). Physical activity recommendations were met by 21.6% of the participants, mainly through leisure activities. Odds of meeting the recommendations were significantly higher in males (OR 4.8, 95% CI 2.5–9.1), individuals ≤57 years (OR 3.0, 95% CI 1.6–5.9), those at active self-reported stages of change for physical activity (OR 2.2, 95% CI 1.2–4.1) and those reporting no barriers to performing physical activity (OR 2.7, 95% CI 1.4–4.9). Median (25th, 75th percentiles) sitting time was 705 (600, 780) min/d. Older age (>57 years) was associated with longer sitting time (>705 min/d) (OR 2.8, 95% CI 1.7–4.6). Preferred methods to support physical activity in routine diabetes care were consultations (38%), structured physical activity sessions (13.4%) and referrals to physical activity facilities (5.6%) delivered by a variety of health care providers. Conclusions The results suggest that intervention strategies should take account of gender, age, opportunities within daily life to promote active behaviour and readiness to change. Offering physical activity consultations is of interest to this study population, thus development and evaluation of interventions are warranted
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