Comparative study of different orographic representations with respect to the Indian summer monsoon simulation

In spectral General Circulation Models that are now widely used in operational weather forecasting and research, the time dependent atmospheric parameters and orography are represented in the form of double series. In such spectral transform methods, Gibbs oscillations appear due to sharp gradients in terrain height, moisture, and cloud fields. The present paper shows the usefulness of different digital filters in reducing the negative values of orography. The application of filters also reduces the heights of the mountain peaks. This affects the Indian region the most, because of the presence of the Himalayas and the Western Ghats. In this paper, an attempt has been made to represent the orography by a new method, called the Filtered Modified Orography (FMO), in which a two dimensional Lanczos filter has been applied in the spectral domain globally with a subsequent local enhancement of the Himalayas and the Western Ghats. The dual advantages of reduction in negative orography values and enhancement of mountain peaks were achieved. A comparison with the envelope orography, where the mean orography is enhanced globally, shows that the new method is able to reduce some of the errors and disparities associated with the envelope technique while retaining some of the advantages of the barrier effect regionally. Results show reasonably good representation of global winds, geopotential and rainfall in FMO representation in T80 model of the National Centre for Medium Range Weather Forecasting

Assessment of two versions of regional climate model in simulating the Indian Summer Monsoon over South Asia CORDEX domain

This study assess the performance of two versions of Regional Climate Model (RegCM) in simulating the Indian summer monsoon over South Asia for the period 1998 to 2003 with an aim of conducting future climate change simulations. Two sets of experiments were carried out with two different versions of RegCM (viz. RegCM4.2 and RegCM4.3) with the lateral boundary forcings provided from European Center for Medium Range Weather Forecast Reanalysis (ERA-interim) at 50 km horizontal resolution. The major updates in RegCM4.3 in comparison to the older version RegCM4.2 are the inclusion of measured solar irradiance in place of hardcoded solar constant and additional layers in the stratosphere. The analysis shows that the Indian summer monsoon rainfall, moisture flux and surface net downward shortwave flux are better represented in RegCM4.3 than that in the RegCM4.2 simulations. Excessive moisture flux in the RegCM4.2 simulation over the northern Arabian Sea and Peninsular India resulted in an overestimation of rainfall over the Western Ghats, Peninsular region as a result of which the all India rainfall has been overestimated. RegCM4.3 has performed well over India as a whole as well as its four rainfall homogenous zones in reproducing the mean monsoon rainfall and inter-annual variation of rainfall. Further, the monsoon onset, low-level Somali Jet and the upper level tropical easterly jet are better represented in the RegCM4.3 than RegCM4.2. Thus, RegCM4.3 has performed better in simulating the mean summer monsoon circulation over the South Asia. Hence, RegCM4.3 may be used to study the future climate change over the South Asia

Contact Pressure Distribution on Subgrade Soil Underlying Geocell Reinforced Foundation Beds

© Copyright © 2019 Dash, Saikia and Nimbalkar. High contact stresses generated in the foundation soil, owing to increased load, causes distress, instability, and large settlements. Present days, geocell reinforcement is being widely used for the performance improvement of foundation beds. Pressure distribution on subgrade soil in geocell reinforced foundation beds is studied through model tests and numerical analysis. The test data indicates that with provision of geocell reinforcement the contact pressure on the subgrade soil reduces significantly. Consequently, the subgrade soil tends to remain intact until large loadings on the foundation leading to significant performance improvement. Through numerical analysis it is observed that the geocells in the region under the footing were subjected to compression and beyond were in tension. This indicates that the geocell reinforcement right under the footing directly sustains the footing loading through mobilization of its compressive stiffness and bending rigidity. Whereas, the end portions of the geocell reinforcement, contribute to the performance improvement in a secondary manner through mobilization of anchorage derived from soil passive resistance and friction

Performance of ballasted track under impact loading and applications of recycled rubber inclusion

© 2018 Chinese Academy of Sciences. All rights reserved. In this paper a review of the sources of impact loads and their effect on the performance of ballasted track is presented. The typical characteristics and implications of impact loading on track deterioration, particularly ballast degradation, are discussed. None of the procedures so far developed to design rail track incorporate the impact that dynamic loading has on the breakage of ballast and therefore it can be said to be incomplete. An intensive study on the impact of induced ballast breakage is needed in order to understand this phenomenon and then use the knowledge gained to further advance the design methodology. A stiff track structure can create severe dynamic loading under operating conditions which causes large scale component failure and increases maintenance requirements. Installing resilient mats such as rubber pads (ballast mat, soffit pad) in rail tracks can attenuate the dynamic force and improve overall performance. The efficacy of ballast mats to reduce structural noise and ground vibration has been studied extensively, but a few recent studies has reported how ballast mats and soffit pads reduce ballast degradation, thus obviating the necessity of a comprehensive study in this direction

Effect of clonidine, by infi ltration and by intravenous route, on scalp block for supratentorial craniotomy

Background: The aim of this research was to study and compare the haemodynamic and analgesic effects of (A) scalp block with bupivacaine 0.25%; (B) scalp block with bupivacaine 0.25% plus clonidine 2 μg/kg; and (C) scalp block with bupivacaine 0.25%, plus intravenous (IV) clonidine 2 μg/kg in supratentorial craniotomies. Method: Sixty patients divided into three equal groups (A, B and C) were administered one of the above combinations. All the patients received propofol-based general anaesthesia. Propofol infusion was started at 25 μg /kg/minute, adjusted with an increment or decrement of 5 μg/kg/minute to obtain an A-line ARX index (AAI) of between 20 and 30 throughout the surgery, and stopped after dural closure. Fentanyl 0.5 μg/kg IV was given if a 20% increase in either heart rate (HR) and/or blood pressure (BP) was observed. HR and BP were monitored throughout the surgery and recorded on pin application, incision (planned 15 minutes after pins), at 15-minute intervals thereafter until dural closure, and every five minutes after dural closure. Propofol and fentanyl requirements were recorded for the duration of the surgery. Results: There was a significant fall in HR, SBP (systolic blood pressure), MAP (mean arterial blood pressure) and RPP (rate-pressure product) after pin application in group B (HR p = 0.018, SBP p = 0.003, MAP p = 0.0042, RPP p = 0.000) and group C (HR p = 0.412, SBP p = 0.01, MAP p = 0.0084, RPP p = 0.001) when compared to group A. Propofol and fentanyl requirements were significantly lower in group B (propofol 67.9% and fentanyl 34.85% less) and group C (propofol 59.21% and fentanyl 36.36% less) when compared to group A. Conclusions: The addition of clonidine, either to the scalp block or intravenously, offers better haemodynamic stability intraoperatively, and reduces analgesic and anaesthetic requirements.Keywords: scalp block, supratentorial craniotom

A CASE REPORT ON BENIGN PROSTATIC HYPERPLASIA WITH HOMEOPATHIC REMEDIES

Benign prostatic hyperplasia (BPH) is characterized by proliferation of the cellular elements of the prostate. The complications faced by elderly people need to be minimized and most of elderly don not prefer a surgical approach. Therefore, treatment of BPH with medicines is prioritized by elderly people. The present case report adds a little to the field that how to treat BPH cases in elderly without surgical approach but with homeopathic formulations. Case report presented here is diagnosed case of BPH having grade III prostatomegaly on USG. Patient presented with increased frequency of urination in feeble stream and sudden urging occasionally. Patient was treated with homoeopathic medication and assessed using Ultrasonography, International Prostate Symptom Score, and Uroflowmetry with significant improvement. Hence, it is suggestive that homoeopathic treatment could be effective in the management of cases of BPH in elderly people. Keywords: Homoeopathy, BPH, Uroflowmetry, International Prostate Symptom Score (IPSS), Constitutional medicine, Organopathic medicine, Sabal serrulat

A Theory of Dual Channel Constraints

The surprising predictability of source code has triggered a boom in tools using language models for code. Code is much more predictable than natural language, but the reasons are not well understood. We propose a dual channel view of code; code combines a formal channel for specifying execution and a natural language channel in the form of identifiers and comments that assists human comprehension. Computers ignore the natural language channel, but developers read both and, when writing code for longterm use and maintenance, consider each channel's audience: computer and human. As developers hold both channels in mind when coding, we posit that the two channels interact and constrain each other; we call these dual channel constraints. Their impact has been neglected. We describe how they can lead to humans writing code in a way more predictable than natural language, highlight pioneering research that has implicitly or explicitly used parts of this theory, and drive new research, such as systematically searching for cross-channel inconsistencies. Dual channel constraints provide an exciting opportunity as truly multi-disciplinary research; for computer scientists they promise improvements to program analysis via a more holistic approach to code, and to psycholinguists they promise a novel environment for studying linguistic processes

A Prospective Study of Doppler Velocimetry in Pregnancy-induced Hypertension in a Rural Population of a Developing Country

Background: Pregnancy-induced hypertension (PIH) remains a great challenge to obstetricians. Doppler velocimetry can detect fetal compromise much before other antepartum tests.Aim: The aim of this study is to detect the changes of uterine artery, umbilical artery and middle cerebral artery in PIH by Doppler velocimetry.Subjects and Methods: This prospective study was conducted on hundred subjects with PIH. Doppler studies were carried, and parameters recorded in uterine, umbilical and middle cerebral artery (MCA) were Systolic/Diastolic ratio, Resistance Index, Cerebro Placental Index (CPI). Fetal outcomes were monitored. Statistical analysis was performed using Epi InfoTM software (Version 3.5.1, CDC, Atlanta). Test for significance was done with student’s t-test and Chi-square where applicable. A P- value of<0.05 was considered as significant.Results: Among the 100 subjects, 76 (76%) of fetuses had abnormal and 24% normal umbilical artery Doppler velocimetry; 62% had abnormal and 38% normal MCA Doppler velocimetry; 64% fetuses had abnormal and 36% normal CPI. In 95% of subjects having abnormal umbilical Doppler studies, caesarean section had to be done for acute fetal distress. Incidence of caesarean section was 61% in abnormal MCA group and 63% in abnormal CPI group. Among 14 patients who had abnormal uterine artery Doppler, four developed pre-eclampsia, 2 IUGR. In patients with notches in uterine artery Doppler, 38% developed pre-eclampsia, 38% had IUGR, 13% babies were still born and 25% of newborns required NICU admission. In umbilical artery Doppler, when S/D ratio was abnormal, 60% developed pre-eclampsia, 40% had IUGR and 40% of newborns had to be admitted in NICU.Conclusion: Doppler study for fetal surveillance in pregnancy-induced hypertension is a very useful device and abnormal umbilical artery and uterine artery velocimetry seems to have worse pregnancy outcomes in the present study. Notch as a single parameter is the best indicator with highest sensitivity and positive predicative values. However, combination of parameters is the best indicator.  Keywords: Doppler study, fetomaternal outcome, pregnancy-induced hypertensio