Heat Effects in Adsorption: Modeling with Equations of State for Confined Fluids

Adsorption is valuable for industrial separation and purification processes and the characterization of porous materials. The amount of adsorbate a given adsorbent can take at a given condition and the associated heat effect are among the most important data for adsorption phenomena. In particular, the study of heats of adsorption plays an important role in the assessment and optimization of energy use in industrial processes. That is because the adsorption process temperature is a key factor that controls local adsorption equilibria and dynamics within adsorption columns. There are different definitions and experimental measurement techniques of heats of adsorption, but this work’s focus is on predicting isosteric and pseudo-isosteric heats of adsorption and the difference in specific heat capacity between the adsorbed and the bulk phases of a gas on an adsorbent using an equation of state for confined fluids. The equation of state used extends the Peng-Robinson equation of state for fluids within solid spherical pores. The adsorption of a variety of pure gases on different zeolites is studied in this research. Zeolites of types A and X are the main focus as they are the adsorbents utilized in many gas adsorption-separation processes. Adsorption isotherms are correlated by means of parameter fitting and their average absolute relative deviations (AARDs) are in the range 1% – 6% for most of the studied systems. The results of isosteric and pseudo-isosteric heats of adsorption are predictions, which generally follow the qualitative experimental trends and have AARDs in the range 21% - 46%. The calculated isosteric heats were used to reflect on the zeolite heterogeneity and energetic levels and to calculate the difference in specific heat capacities. This was in the range of -0.5R to 3R, which is the same order of magnitude of results obtained from literature

Impact of Betaine Supplementation as Anti Stress on Some Hematological Parameters and Thermoregulatory Responses of Aberdeen Angus Cows in Arid Subtropical Regions

This study aimed to investigate the effects of betaine supplementation on some hematological and physiological parameters of Aberdeen Angus cows. Twelve cows were divided randomly into two equal groups (6 cows each) and each group was treated for 150 successive days. All experimental animals were fed 60% of their requirements as a concentrate mixture and the rest of other requirements was covered from wheat strew ad-libitum. In addition to basal diet, animals in experimental group were supplemented with 30 g betaine hydrochloride per day. Air temperature and relative humidity were recorded during the experimental days to calculate the current temperature–humidity index (THI). Blood samples were collected during experimental period from jugular vein. Rectal temperature (RT), pulse rate (PR), respiration rate (RR), skin temperature (ST) and hair temperature (HT) were recorded during the experimental days. The obtained results showed that the average values of THI were between 71.6 to 74.78 at 08:00 am and 77.09 to 83.01 at 02:00 pm during the experimental period which indicates exposure of animals to heat stress. There were no significant differences among groups in WBC, HCT, MCV, MCH, MCHC and PLT. Moreover, RBC and HGB was higher (P < 0.05) in betaine group than control. adding betaine had no significant decrease in RR, ST, HT and ET. While, significant decrease in RT and PR was observed at 02:00 pm of experimental animal. It is concluded that betaine may be improved some hematological parameters and thermoregulatory responses of Aberdeen Angus cows under New Valley arid areas

Effect of Antioxidant supplementation on Some Hematological Parameters and Thermoregulatory Responses of Aberdeen Angus Cows During Hot Season in Arid Subtropical Regions

This work aims to investigate the impact of some antioxidants, i.e., zinc sulfate (ZnS) administration, vitamin E and selenium (E-Sel) injection on hematological parameters and thermoregulatory responses of Aberdeen Angus cows. Sixteen cows were randomly divided into 4 equal groups (4 cows each), First group served as a control (G1); second group was received E-Sel injection at rate of 15 ml/ head / 15day) (G2); third group was fed on ZnS with an average rate of 200 mg/head/ daily (G3) and the fourth one was fed on ZnS in combination with E-Sel injection (G4). All experimental cows were fed 60% of their requirements as CFM and the rest of other requirements was covered from wheat strew ad libitum. In addition, the AT and RH% were recorded during the experimental days to calculate the current THI. Blood samples were collected during experimental period from jugular vein. Physiological parameter measurements were recorded during the experimental days. The obtained results showed that the average values of THI were between 69.04 and 85.46 during the experimental period. Treated cows with E-Sel recorded the highest values of hematological parameters in terms of WBC, RBC, HB, HCT and PLT compared with other groups. Using antioxidant agents had significant decrease in RR, PR, and HT. While, slightly decrease in RT, ST and ET was recorded of experimental animal. It is concluded that some antioxidants could improve hematological parameters and thermoregulatory responses of Aberdeen Angus cows under hot climatic conditions

A program for obese youth at-risk for diabetes in Qatar

Background: Obesity is an international public health problem well documented in Qatar among children and adolescents and contributes to diabetes, a disease already highly prevalent in the country. We describe an intervention program developed for obese youth conducted by the Qatar Diabetes Association (QDA). Methods: The QDA conducts a 3-day structured program for obese youth at-risk for developing diabetes which includes physical activities, games and workshops aimed to increase awareness and guide improved diet, activity and related lifestyle choices. Using motivational interviewing techniques, obese youth develop action plans to modify diet and exercise which were shared with parents to promote collaboration and support. Results: In 2011, one girls' camp (n = 15, mean age 12 years) and one boys' camp (n = 17, mean age 13 years) were held. All participants were considered obese: girls mean BMI = 31 kg/m2 (standard deviation (SD) 4.2) and boys mean BMI 35 kg/m2 (SD = 4.7). Youth reported fast food consumption at least twice a week by 6 (40 %) of girls and 10 (59 %) of boys and there was low self-declared frequency of daily physical activity (1 girl and 5 boys). Many stated their weight made their life worse due to fatigue, poor agility, or difficulty finding clothes. When individualized coaching was proposed, 87 % and 100 % of girls and boys felt ready to devise an action plan for improved health. Conclusion: The new national preventative healthcare mandate could facilitate modification and expansion of these QDA educational and behavioural intervention programs as part of the wider strategy to combat obesity in Qatar.qscienc

Discovery of os cordis in the cardiac skeleton of chimpanzees (Pan troglodytes)

Cardiovascular diseases, especially idiopathic myocardial fibrosis, is one of the most significant causes of morbidity and mortality in captive great apes. This study compared the structure and morphology of 16 hearts from chimpanzees (Pan troglodytes) which were either healthy or affected by myocardial fibrosis using X-ray microtomography. In four hearts, a single, hyperdense structure was detected within the right fibrous trigone of the cardiac skeleton. High resolution scans and histopathology revealed trabecular bones in two cases, hyaline cartilage in another case and a focus of mineralised fibro-cartilaginous metaplasia with endochondral ossification in the last case. Four other animals presented with multiple foci of ectopic calcification within the walls of the great vessels. All hearts affected by marked myocardial fibrosis presented with bone or cartilage formation, and increased collagen levels in tissues adjacent to the bone/cartilage, while unaffected hearts did not present with os cordis or cartilago cordis. The presence of an os cordis has been described in some ruminants, camelids, and otters, but never in great apes. This novel research indicates that an os cordis and cartilago cordis is present in some chimpanzees, particularly those affected by myocardial fibrosis, and could influence the risk of cardiac arrhythmias and sudden death

Crystal structure of A-site deficient La0.2Sr0.2-xCaxTiO3 perovskite at ambient conditions and high temperatures : a neutron powder diffraction study

The authors thank the Government of the United Arab Emirates for sponsoring this project, the EPSRC for Platform grant support and the Royal Society for a Wolfson Research Merit Award.The crystal structures of several solid solutions of the perovskite La0.2Sr0.7-xCaxTiO3 were determined using the Rietveld analysis of neutron powder diffraction patterns collected at room temperature and at high temperatures. At room temperature, samples showed a tetragonal I4/mcm symmetry for compositions with 0.1 ≤ x ≤ 0.35 followed by a phase transition to orthorhombic Pbnm symmetry for compositions with 0.4 ≤ x ≤ 0.7. Samples with the orthorhombic symmetry showed two reversible phase transitions in the temperature range 20oC – 900oC. The first transition was a discontinuous Pbnm – I4/mcm around 300oC and the second was a continuous I4/mcm - Pm3 ̅m transition below 900oC. The lower symmetries resulted from very small distortions and changes in tilts of the BO6 octahedra of this perovskite; which was a direct result from the A-site ionic radius mismatch.Publisher PDFPeer reviewe

Improving Fatigue Performance of GFRP Composite Using Carbon Nanotubes

Glass fiber reinforced polymers (GFRP) have become a preferable material for reinforcing or strengthening reinforced concrete structures due to their corrosion resistance, high strength to weight ratio, and relatively low cost compared with carbon fiber reinforced polymers (CFRP). However, the limited fatigue life of GFRP hinders their use in infrastructure applications. For instance, the low fatigue life of GFRP caused design codes to impose stringent stress limits on GFRP that rendered their use non-economic under significant cyclic loads in bridges. In this paper, we demonstrate that the fatigue life of GFRP can be significantly improved by an order of magnitude by incorporating Multi-Wall Carbon Nanotubes (MWCNTs) during GFRP fabrication. GFRP coupons were fabricated and tested under static tension and cyclic tension with mean fatigue stress equal to 40% of the GFRP tensile strength. Microstructural investigations using scanning electron microscopy (SEM) and Fourier Transform Infrared (FTIR) spectroscopy were used for further investigation of the effect of MWCNTs on the GFRP composite. The experimental results show the 0.5 wt% and the 1.0 wt% MWCNTs were able to improve the fatigue life of GFRP by 1143% and 986%, respectively, compared with neat GFRP

Clinical experience with insulin detemir, biphasic insulin aspart and insulin aspart in people with type 2 diabetes: Results from the Qatar cohort of the A 1 chieve study

Background: The A 1 chieve, a multicentric (28 countries), 24-week, non-interventional study evaluated the safety and effectiveness of insulin detemir, biphasic insulin aspart and insulin aspart in people with T2DM (n = 66,726) in routine clinical care across four continents. Materials and Methods: Data was collected at baseline, at 12 weeks and at 24 weeks. This short communication presents the results for patients enrolled from Qatar. Results: A total of 91 patients were enrolled in the study. Two insulin analogue regimens were used in the study. Study patients had started on or were switched to biphasic insulin aspart (n = 88), insulin detemir (n = 2), and other insulin combinations (n = 1). At baseline glycaemic control was poor for both insulin naïve (mean HbA 1 c: 10.9%) and insulin users (mean HbA 1 c: 9.1%) groups. After 24 weeks of treatment, all the study groups showed improvement in HbA 1 c (insulin naïve: −1.8%, insulin users: −1.3%). Major hypoglycaemia did not occur in the study patients. SADRs were reported in 1.4% of insulin users. Conclusion: Starting or switching to insulin analogues was associated with improvement in glycaemic control with a low rate of hypoglycaemia

Effect of Physical Education Lessons on Selected Blood Content Parameters

The purpose of this investigation was to examine the effect of regular physical education lessons on red blood cell (RBC). hemoglobin (Hb). hematocrit (Hct). mean corpuscular hemoglobin (MCH)and mean corpuscular Volume (MCV). Thirty-two elementary students at a mean age of 10.98 years were assigned to either experimental group or control group. The experimental group participated in two physical education lessons per week for ten weeks All subjects were pre- and post-tested for RBC, Hb, Hct, MCH and MCV. Paired t-test revealed no significant statistical differences From pre to post participation in both groups for all blood variables. Also. no significant differences were found between the two groups in all blood variables. These results suggest that regular physical education lessons had no significant effect on the selected blood variables

Effect of Physical Education Lessons on Selected Blood Content Parameters

The purpose of this investigation was to examine the effect of regular physical education lessons on red blood cell (RBC). hemoglobin (Hb), Hematocrit (HCT). mean corpuscular hemoglobin (MCH). and mean corpuscular volume (MCV). Thirty-two elementary students at a mean age of 10.98 years were assigned to either experimental group or control group. The experimental group participated in two physical education lessons per week for ten weeks. All subjects were pre- and post-tested for RBC, Hb, Hct, MCH and MCV. Paired t-test revealed no significant statistical differences From pre to post participation in both groups for all blood variables. Also, no significant differences were found between the Two groups in all blood variables. These results suggest that regular physical education lessons had no significant effect on the selected blood variables