DESIGN, FACILE SYNTHESIS, AND BIOLOGICAL EVALUATION OF NOVEL 1,3-THIAZINE DERIVATIVES AS POTENTIAL ANTICONVULSANT AGENTS

Objective: Chalcones and their heterocyclic analogs represent an important class of small molecules having anticonvulsant activities. Therefore, inthis study, the synthesis and anticonvulsant activity of some new chalcones and 1,3-thiazines were described.Methods: The reaction of 1-acetylnaphthalene with substituted aromatic aldehydes in the presence of aq. NaOH afforded corresponding chalconeswhich upon further cyclization with thiourea resulted in 1,3-thiazine derivatives. The newly synthesized compounds were tested for anticonvulsantactivity by pentylenetetrazole-induced seizures method using diazepam as standard.Results: Most of the compounds showed good anticonvulsant activity but is less than diazepam. 1,3-thiazines were more potent than chalconesand among them, compound P4 containing 4-fluorophenyl substituents on the thiazine moiety was more potent as it has prolonged the onset ofconvulsions by 155.2 seconds.Conclusion: We described the synthesis and anticonvulsant activity of novel chalcones and 1,3-thiazine derivatives. 1,3-thiazines are more activeanticonvulsant agents than chalcones and in particular compounds with electron withdrawing substituents.Keywords: Chalcone, 1,3-thiazine, Pentylenetetrazole

Leachate Pressure Effect on a System Reliability-Based Design of Reinforced Soil Walls for a Vertical Expansion of MSW Landfills

The issue of vertical capacity expansion of municipal solid waste (MSW) landfills with reinforced soil walls (RSWs) is addressed in the present investigation. The influence of different conditions of leachate levels in MSW landfills is a major cause of translational failures. Poor hydraulic conductivity, clogging of drainage because of fines, and freezing of drainage in landfills are the crucial factors of the buildup of leachate pressure. Heterogeneity and different fill ages in MSW landfills gradually change the inherent properties of landfills. The assumption-independent component failures of sliding, eccentricity, bearing capacity, tension, and pullout modes in predicting the series system reliability index of RSWs against translational failure under six leachate level conditions may produce large errors because component failures are usually dependent on one another. Therefore, the present paper demonstrates the feasibility of considering dependent failure modes to estimate the dimensions of RSWs to maintain the external and internal stability under six different leachate buildup conditions. The variability associated with the cohesion of solid waste, the apparent cohesion between liner components beneath the wedges, the friction angle of MSW, and the interface friction angle beneath the wedges is considered for the estimation of the lower bound of the series system reliability index. The limit equilibrium method is employed to assess the stability of an RSW for an expanded MSW landfill. Further, the design charts for the optimum values of width and height of the RSW are provided for different leachate levels (hw) under six leachate buildup conditions by targeting various lower bounds of a system reliability index ≥3.0. The design values of the number of reinforcement layers (n) are also provided corresponding to the optimum dimensions of the RSW subjected to different leachate levels

Reliability Analysis of Soil Slopes

Slope stability analysis is a classical problem of geotechnical engineering characterized by many sources of uncertainty. Some of these sources are connected to the uncertainties of soil properties involved in the analysis. Current practice of slope stability analysis relies in the deterministic characterization and assessment of performance of embankments, excavations and Municipal Solid Waste (MSW) landfills. These slopes have been evaluated in terms of the factor of safety, where the shear strength mobilized along the failure envelop is compared with the shear stresses generated due to self-weight of the soil mass and surcharge loading on the slope. The significant uncertainties associated with the shear strength and shear stresses render deterministic modeling potentially misleading. For example, two slopes with the same factor of safety can have significantly different probabilities of failure

Effect of Fiber Reinforcement on CBR Behavior of Lime Blended Expansive Soils: Reliability Approach

Use of synthetic fibers as reinforcement to stabilize expansive soils is gaining momentum. As a contribution towards this growing field of research two different types of synthetic fibers, Fiber Mesh® and Fiber Cast®, were evaluated as a stabilization alternative for expansive soils in the presence of lime. California Bearing Ratio (CBR) is chosen as a performance indicator as it is a good pointer towards pavement effectiveness. Variables such as length and amount of the fibers as well as curing period were studied. Both deterministic and probabilistic (or reliability) analysis is presented in this paper. While the deterministic analysis helps in understanding the measured experimental data, the probabilistic approach accounts for the stochastic nature of the experimental data and provides a better rationale for the design methods. The deterministic approach showed that the improvement in CBR increased with higher fiber contents and longer lengths and the effect was prominent when lime was used as a stabilizer. There were some exceptions to this behavior, which were noted in the paper. The probabilistic analysis showed that the amount and lengths of fibers were important factors in CBR strength. It was also determined that the variation in the target CBR value had considerable effect on optimizing the length and amount of the fibers

Histogenesis of Peyer’s patches in Ovine foetus (Ovis aries)

Tissue pieces of jejunum and ileum from different prenatal age groups of sheep were collected from Corporation slaughter house, Perambur, Chennai. By three months of foetal age in sheep, the Peyer’s patches appeared as an aggregation of lymphocytes in the propria submucosa of the jejunum and ileum. The lymphocytic aggregation appeared only in the antimesenteric part of the jejunum and ileum. By four months of foetal age, the circumscribed nodular aggregations of lymphocytes were found enlarged giving a follicle-like appearance. The capsular connective tissue was predominated by reticular fibres and a few collagen fibres. The dome area of the follicle consisted of closely packed small-sized lymphocytes which appeared darker than the basal area. The smooth muscle fibres of muscularis mucosae were not continuous throughout and were absent in the follicle having domes. In five months-old foetuses, the jejunal and ileal Peyer’s patches were distinctly observed as follicles. The follicle showed a distinct outer cortex and an inner lighter medulla. Numerous small-sized lymphocytes were observed in the outer cortex and few lymphoblasts, medium sized lymphocytes and reticular cells were observed in the medulla. Keywords: Histogenesis; Peyer’s patches; Ovine foetus

Assessment of GPS radiosonde descent data

Radiosondes are widely used to obtain basic meteorological parameters such as pressure (<i>P</i>), temperature (<i>T</i>), relative humidity (RH) and horizontal winds during the balloon ascent up to the altitude of balloon burst, usually ~ 32–35 km. Data from the radiosondes released from Gadanki (13.5° N, 79.2° E), a tropical station in India, have been collected during the ascent and during the descent as well without attaching any parachute or its equivalent since the year 2008. In the present study an attempt has been made to characterize the radiosonde descent data with the main objective of exploring its usefulness and reliability for scientific purposes. We compared the data obtained during ascent and descent phases of the same sounding. The mean differences in <i>T</i>, RH and horizontal winds between ascent and descent data are found to be small and are sometimes even within the uncertainty of the measurements and/or expected diurnal variation itself. The very good consistency observed between the ascent and the descent data shows that one more profile of the meteorological parameters can be constructed within 3 h of time of balloon launch practically at no additional cost. Further checks are done by utilizing the 3-hourly radiosonde observations collected during the Tropical Tropopause Dynamics campaigns conducted at Gadanki. In the process of checking the consistency between the radiosonde ascent and descent data, several new findings are arrived at and are reported in this study. In general, it has taken more than half an hour for the balloon to reach the ground from the burst altitude. It is also observed that the fall velocity is close to 10 m s⁻¹ near the surface. Finally, it is suggested to record the observations also when the balloon is descending as this information is useful for scientific purposes

Microstrip Line Fed Leaky Wave Antenna with Shorting Vias for Wideband Systems

In this work a complex structured shorted vias microstrip leaky wave antenna is designed and analysed. A Leaky wave antenna is a travelling wave structure with complex propagation constant. When shorting vias are loaded in a periodic structure the fundamental resonant mode shows some stop band characteristics and some of the modes will strongly attenuated. Three different types of iterations are examined in this work with and without defected ground structures. The defected ground structure based leaky wave antennas are showing better performance characteristics with respect to efficiency and phase. A micro strip line feeding with impedance of 50 ohms at both ports are providing excellent impedance matching to the conducting path on the microstrip surface. The shorting vias are suppressing certain higher order frequency bands and providing excellent wide band characteristics with low loss

A Study of nature of the Photovoltaic modules under the influence of partial shading effect

The behaviour of the solar photovoltaic array will be rapidly changing under the influence of partial shading phenomenon. When two (or) more photovoltaic modules are embedded in series, then the total output voltage and the net output power obtained from the series connected photovoltaic modules will mainly depends upon the solar insolation which is being projected upon each and every module respectively. Small perturbation in solar irradiation levels will lead to large considerable change in the output parameters. This paper mainly focuses on observing the effect of partial shading on photovoltaic modules which are connected in series. The main objective of this paper is to examine about the mismatching phenomenon that occurs while tracking the global maxima point which plays a vital role in extracting maximum power from solar photovoltaic array in an effective manner