Laboratory mix design of asphalt mixture containing reclaimed material

This paper presents a study on the production of asphalt test specimens in the laboratory containing reclaimed asphalt. The mixtures considered were stone mastic asphalt concrete mixtures containing up to 30% of reclaimed asphalt. Specimens were compacted to the reference density obtained from the Marshall mix design. Gyration compaction method was used for preparing specimens for the experimental programme, while coring and cutting methods and X-ray computed tomography (CT) were used to investigate the change in properties within the specimens and to validate the selected methodology.The study concluded that gyratory compaction is suitable to produce homogeneous test specimens also for mixtures containing high amount of reclaimed asphalt. Nevertheless, preliminary trials for each material are mandatory, as well as final coring and trimming of the specimens due to side effects

Photocatalytic Z-Scheme Overall Water Splitting: Recent Advances in Theory and Experiments

Photocatalytic water splitting is considered one of the most important and appealing approaches for the production of green H2 to address the global energy demand. The utmost possible form of artificial photosynthesis is a two-step photoexcitation known as “Z-scheme”, which mimics the natural photosystem. This process solely relies on the effective coupling and suitable band positions of semiconductors (SCs) and redox mediators for the purpose to catalyze the surface chemical reactions and significantly deter the backward reaction. In recent years, the Z-scheme strategies and their key role have been studied progressively through experimental approaches. In addition, theoretical studies based on density functional theory have provided detailed insight into the mechanistic aspects of some breathtakingly complex problems associated with hydrogen evolution reaction and oxygen evolution reaction. In this context, this critical review gives an overview of the fundamentals of Z-scheme photocatalysis, including both theoretical and experimental advancements in the field of photocatalytic water splitting, and suggests future perspectives

Dual-Band Bandpass Filter with Dumbbell Shaped Defective Ground Structure

A dumbbell shaped defective ground structure (DGS) is implemented to improve the performance of an existing dual-band bandpass filter topology. The filter design is based on parallel-coupled lines connected to matched transmission lines. Various positions and dimensions of dumbbell DGSs are implemented and their effects on the filter performance are investigated. It is found that the utilisation of dumbbell shaped DGSs in this topology improve the steepness of the responses for the first and second passbands with centre frequencies of 1.365 and 2.932 GHz respectively. The optimised dimensions of the DGS are 5 x 5 mm2 for both its rectangular slots connected by a 0.5 mm narrow slot width. The optimised positions of the DGSs are located at the centre and the edges of the parallel-coupled lines. The simulated and measured results of the filter are analysed and discussed in this paper

Evaluation of the diuretic potentials of naringenin in hypercholesterolemic rats

Purpose: To investigate the diuretic potentials of naringenin (NGN) in obesity induced in rats by high fat diet (HFD).Methods: To prepare HFD, normal pellet diet was crushed and thoroughly mixed with cholesterol powder (1 % w/w). The mixture was mixed with some water and made into pellets which were then oven-baked to dry. Four groups of male Wistar albino rats (n = 6) were used for the study. Normal control (group I) received normal pellet diet. Group 2 (HFD-only) was fed HFD for 28 days, while Groups 3 and 4 were co-administered HFD and NGN at doses of 50 and 100 mg/kg, respectively. All treatments were given orally, and lasted for 28 days. Twenty-four hours after the last dose of NGN, blood was collected from all rats and total cholesterol levels determined to confirm obesity. Thereafter, the rats were placed in metabolic cages and urine samples were collected at two time-points (5 and 24 h) for measurement of urine volume, urinary pH, conductivity and electrolyte levels (Na, K and Cl).Results: Treatment with HFD resulted in significantly (p < 0.05) increased serum cholesterol level (178.83 ± 5.43 mg/dL) when compared to normal control rats (88.17 ± 4.04 mg/dL). It also led to decrease in urinary volume (~50 %) at both time points (5 and 24 h) and in excretion of urinary electrolytes (sodium, potassium and chloride ions). However, the changes in these parameters were significantly reversed by NGN administration (p < 0.05).Conclusion: These results demonstrate the diuretic activity of NGN in HFD-induced obese rats. Thus, NGN can be further explored for use in combination with hypolipidemic agents to tackle obesity.Keywords: High-fat diet, Hypercholesterolemia, Naringenin, Obesit

FORMULATION OPTIMIZATION AND EVALUATION OF GASTRORETENTIVE TABLETS OF ONDANSETRON HCL

The aim of the work is to design Gastroretentive tablets of Ondansetron HCl for gastric retention by using 32 factorial designs. Floating tablets of Ondansetron HCl were prepared by direct compression method using polymers, sodium alginate and excipient. Gastroretentive tablets of Ondansetron HCl were successfully prepared by effervescent technique using different gel forming polymers- HPMC K200M, and sodium alginate. Formulation was optimized by design expert software. Floating tablets were evaluated for floating time, floating lag time, drug content, raft measurement and in vitro dissolution profile. The lag time is between 17-22 sec and floating time of the formulations for 12 hrs. The best fit model is Korsemeyer Peppas Model. From the study it is proof that the sustain release by floating tablets of Ondansetron HCl can be develop. Optimized batch selected was A3, The prepared gastroretentive test formulation was found to exhibit satisfactory physico-chemical characteristics at the end of 3 months, during the stability studies. The optimized formulation A3 was found to be stable at 400C/ 75% RH. Keywords: Gastric retention time, Ondansetron HCl, HPMC, sodium alginate, measurement of raft, Factorial design, stability studies.Â

Effectiveness of Misoprostol in the Management of Intra-Uterine Foetal Death

Background: Misoprostol \u2013 a prostaglandin E1 analogue is effective in the induction of labour in the 2nd and 3rd trimester pregnancies. There is paucity of information in the use of misoprostol for labour induction in our setting. Method: Non-randomized clinical trial. Results: Thirty-four consecutive patients with real time ultrasonographically confirmed intrauterine fetal demise from 14 weeks gestation were recruited into the study. Twelve patients had oral administration while 22 were given misoprostol via the vaginal route. The mean age and parity of these patients where 26.7 \ub1 6.8 years and 3.2 \ub1 3.3 respectively. The mean uterine size at induction was 24.5 \ub1 8.2 weeks. Mean onset of painful uterine contractions was 5.02 \ub1 5.2 hours (Range 0.5 \u2013 22 hours) while the mean induction \u2013 delivery interval was 14.6 \ub1 10.4 hours (Range 3-46 hours). The success rate of induction was 100% within 48 hours. Induction \u2013 delivery interval was not dependent on uterine size/Gestational age. Side effects encountered were minor namely nausea and vomiting. There were more side effects on oral administration. Conclusion: Misoprostol is effective in the termination of 2nd and 3rd trimester pregnancies associated with intrauterine fetal demise. Studies are needed to compare the efficacy of misoprostol with oxytocin in the induction of labour with live fetuses in our setting.Introduction : Le Misoprostol un prostaglandin E1 analogue est efficace dans le d\ue9clenchement dans le 2\ue8me et 3\ue8me trimestres des grossesses. Il y a une p\ue9nurie de l'information dans l'utilisation de misoprostol pour le d\ue9clenchement dans notre mileu. M\ue9thode : Proc\ue8s clinique non-randomis\ue9 R\ue9sultats : Trente-quatre patients cons\ue9cutifs avec le d\ue9c\ue8s de fetal intraut\ue9rinaire confirm\ue9 \ue0 travers un vrai utrasonographie \ue0 partir de 14 semaines de la gestation ont \ue9t\ue9 r\ue9cruit\ue9s pour cette \ue9tude. Douze patients avaient eu une administration orale tandis que 22 ont \ue9t\ue9 donn\ue9s misoprostol \ue0 travers la voie vaginale. L'\ue2ge moyen et parit\ue9 des patients \ue9taient 26,7 +- 6,8 ans et 3,2 +- 3,3 respectivement. La taille moyenne de l'ut\ue9rine pendant le d\ue9clenchement \ue9tait 24,5 +- 8,2 semaines. Moyen du commencement de la douleur de la contraction d'ut\ue9rine \ue9tait (5,02 +- 5,2 heures (groupe 0,5 \u2013 22 heures) tandis que moyen de d\ue9clenchement \u2013 accouchement interval \ue9tait 14,6 +- 10,4 heures. (Tranche \u2013 3 \u2013 46 heures) Le taux du succ\ue8s du d\ue9clenchement \ue9tait 100% en moins de 48 heures. D\ue9clenchement - accouchement interval n'\ue9tait pas dependant sur la taille ut\ue9rine/l'\ue2ge gestational. R\ue9actions secondaire \ue9prouv\ue9es \ue9taient peu \ue0 savoir : la naus\ue9e et vomissements. Il y avait plus de r\ue9actions secondaires sur l'administration orale. Conclusion : Le Misoprostol est tr\ue8s efficace dans la termination de 2\ue8me et 3\ue8me trimestres des grossesses ayant rapport avec le d\ue9c\ue8s de fetal intraut\ue9rine. On a besoin des \ue9tudes pour comparer l'efficacit\ue9 de misoprostol avec oxytocin dans le d\ue9clenchement avec des foetus vivant dans notre milieu

Effect of Newtonian and non-Newtonian flow in subject specific carotid artery

Advances in the numerical simulation techniques has immensely helped in the demonstrating the importance of blood flow through elastic arteries and evaluating the disease progression and flow dynamics of cardiovascular diseases such as atherosclerosis. The present work deals with a case study of a patient diagnosed with partial narrowing of entire cervical segment of Internal Carotid Artery (ICA), while Common Carotid Artery (CCA) and External Carotid Artery (ECA) appears to be normal. Subject specific 3D carotid bifurcation CAD model is generated based on CT-angio scan data using MIMICS-14.0 and numerical analysis is performed using Computational Fluid Dynamics (CFD) in ANSYS-CFX-14.0. Pulsatile blood flow through the subject-specific artery is investigated to study the influence of rheology on the haemodynamics in the blood flow. The simulation results obtained through Carreau-Yasuda and Newtonian models are investigated. Flow behaviour observed during peak systole exhibits significant difference in the spatial parameters between both the Newtonian and nonNewtonians models. The comparison of local shear stress magnitude in CCA, ICA and ECA demonstrates that WSS is highly influenced by the shear thinning property of blood. This variation is also observed artery branches with reduced lumen diameter, lumen narrowing due to stenosis and in the bifurcation zone

Influence of blood pressure and rheology on oscillatory shear index and wall shear stress in the carotid artery

Atherosclerosis is a localized complication dependent on both the rheology and the arterial response to blood pressure. Fluid–structure interaction (FSI) study can be effectively used to understand the local haemodynamics and study the development and progression of atherosclerosis. Although numerical investigations of atherosclerosis are well documented, research on the influence of blood pressure as a result of the response to physio–social factors like anxiety, mental stress, and exercise is scarce. In this work, a three-dimensional (3D) Fluid–Structure Interaction (FSI) study was carried out for normal and stenosed patient-specific carotid artery models. Haemodynamic parameters such as Wall Shear Stress (WSS) and Oscillatory Shear Index (OSI) are evaluated for normal and hypertension conditions. The Carreau–Yasuda blood viscosity model was used in the FSI simulations, and the results are compared with the Newtonian model. The results reveal that high blood pressure increases the peripheral resistance, thereby reducing the WSS. Higher OSI occurs in the region with high flow recirculation. Variation of WSS due to changes in blood pressure and blood viscosity is important in understanding the haemodynamics of carotid arteries. This study demonstrates the potential of FSI to understand the causes of atherosclerosis due to altered blood pressures