Monte Carlo model for electron degradation in methane

We present a Monte Carlo model for degradation of 1-10,000 eV electrons in an atmosphere of methane. The electron impact cross sections for CH4 are compiled and analytical representations of these cross sections are used as input to the model.model.Yield spectra, which provides information about the number of inelastic events that have taken place in each energy bin, is used to calculate the yield (or population) of various inelastic processes. The numerical yield spectra, obtained from the Monte Carlo simulations, is represented analytically, thus generating the Analytical Yield Spectra (AYS). AYS is employed to obtain the mean energy per ion pair and efficiencies of various inelastic processes.Mean energy per ion pair for neutral CH4 is found to be 26 (27.8) eV at 10 (0.1) keV. Efficiency calculation showed that ionization is the dominant process at energies >50 eV, for which more than 50% of the incident electron energy is used. Above 25 eV, dissociation has an efficiency of 27%. Below 10 eV, vibrational excitation dominates. Contribution of emission is around 1.2% at 10 keV. Efficiency of attachment process is 0.1% at 8 eV and efficiency falls down to negligibly small values at energies greater than 15 eV. The efficiencies can be used to calculate volume production rate in planetary atmospheres by folding with electron production rate and integrating over energyComment: 12 figures, 3 table

‘old foley’s in a new bottle’- USE OF FOLEY’S CATHETER IN ANTERIOR MAXILLARY WALL FRACTURES

ABSTRACT Management of comminuted zygomaticomaxillary fractures are is an entity that has always tested the skill of surgeons. A variety of methods have been coined over the years for management of these fractures. Packing the antrum with a gauze or  balloon can be used in much comminuted fractures especially with anterior antral wall communication. Internal immobilization with a Foley’s balloon catheter is being used widely in Blow out fractures of orbit and rarely in tripod fractures. Despite a thorough search, not much literature could be found of its use in anterior maxillary wall fractures. The purpose of this article is to appraise this technique in anterior maxillary wall fractures.

The inadequacy of South Africa’s black economic empowerment policy

Vrinda Chopra analyses the detrimental effects of the BBBEE on smallholder farmers and cooperatives in South Africa

Sentinel-1 data exploitation for terrain deformation monitoring

Persistent Scatterer interferometry (PSI) is a group of advanced differential interferometric Synthetic Aperture Radar (SAR) techniques used to measure and monitor terrain deformation. Sentinel-1 has improved the data acquisition throughout and, compared to previous sensors, increased considerably the Differential Interferometric SAR (DInSAR) and PSI deformation monitoring potential. The effect of the refractive atmosphere on the interferometric phase and phase unwrapping ambiguity are two critical issues of InSAR. The low density of Persistent Scatterer (PS) in non-urban areas, another critical issue, has inspired the development of alternative approaches and refinement of the PS chains. Along with the efforts to develop methods to mitigate the three above-mentioned problems, the work presented in this thesis also deals with the presence of a new signal in multilooked interferograms which cannot be explained by noise, atmospheric or earth surface topography changes. This paper describes a method for atmospheric phase screen estimation using rain station weather data and three different data driven procedures to obtain terrain deformation maps. These approaches aim to exploit Sentinel-1 highly coherent interferograms and their short revisit time. The first method called the splitting makes uses of the power spectrum of the interferograms to split the signals into high and low frequency, and following a mutually exclusive consecutive processing chain for the two sets. This approach has resulted in greater density of PSs with decreased phase unwrapping errors. The second approach, called Direct Integration (DI), aims at providing a very fast and straightforward approach to screen wide areas and easily detect active areas. This approach fully exploits the coherent interferograms from the consecutive images provided by Sentinel-1 resulting in a very high sampling density. However, it lacks robustness and its usability lays on the operator experience. The third method, called PSIG (Persistent Scatterer Interferometry Geomatics) short temporal baseline, provides a constrained application of the PSIG chain, the CTTC approach to the PSI. It uses short temporal baseline interferograms and do not assume any deformation model for point selection. It is also quite a straightforward approach and a perfect complement to the direct integration approach. It improves the performances of the standard PSIG approach, increasing the PS density and providing robust measurements. The effectiveness of the approaches is illustrated through analyses performed on different test sites.La técnica Persistent Scatterer Interferometry (PSI) es un grupo de técnicas avanzadas de radar de apertura sintética interferométrica diferencial (SAR) que se utiliza para medir y monitorear losmovimientos del terreno. Sentinel-1 ha mejorado sensiblemente la adquisición de datos y, en comparación con los sensores SAR anteriores, ha aumentado considerablemente el potencial uso de la interferometría diferencial SAR y del PSI para medir y monitorizar desplazamientos del terreno. El efecto de la atmósfera sobre la fase interferométrica y la naturaleza ambigua de esta son dos cuestiones críticas de InSAR. Además, la baja densidad de Persistent Scatterer (PSs) en áreas no urbanas, es otro tema crítico que ha inspirado el desarrollo de enfoques alternativos y el refinamiento de las cadenas PS existentes. Junto con los esfuerzos por desarrollar métodos para mitigar los tres problemas antes mencionados, el trabajo presentado en esta tesis también aborda la presencia de una nueva señal en interferogramas multilooked que no puede explicarse por cambios de ruido, atmosféricos o topográficos de la superficie terrestre. Esta tesis describe un método para la estimación de la fase atmosférica utilizando datos meteorológicos adquiridos in-situ y tres aproximaciones diferentes basadas en datos Sentinel-1 para obtener mapas de deformación del terreno. Estos enfoques tienen como objetivo explotar los interferogramas altamente coherentes proporcionados por Sentinel-1 gracias a su corto tiempo de revisita. El primer método llamado división hace uso de filtros en el dominico frecuencial de los interferogramas para dividir las señales en alta y baja frecuencia, y siguiendo una cadena de procesamiento consecutiva independiente para cada clase. Este enfoque ha dado como resultado una mejora substancial de PS minimizando los errores debidos al desenrollado de fase. El segundo enfoque, llamado Integración Directa (DI), tiene como objetivo proporcionar un enfoque muy rápido y sencillo para examinar áreas amplias y detectar fácilmente áreas activas. Este enfoque aprovecha al máximo los interferogramas coherentes de las imágenes consecutivas proporcionadas por Sentinel-1, lo que da como resultado una densidad de muestreo muy alta. Sin embargo, carece de robustez y su usabilidad depende de la experiencia del operador. El tercer método, llamado PSIG (Persistent Scatterer Interferometry Geomatics) de línea de base temporal corta, proporciona una aplicación restringida de la cadena PSIG, el enfoque CTTC para el PSI. Utiliza interferogramas de línea base temporales cortos y no asume ningún modelo de deformación para la selección de puntos. Su uso es complementario al enfoque de integración directa proporcionando robustez en las zonas. Mejora el rendimiento del enfoque estándar de PSIG, aumentando la densidad de PS y proporcionando mediciones robustas. La efectividad de los enfoques se ilustra a través de análisis realizados en diferentes sitios de prueba.Postprint (published version

Can SMEs address the agenda of radical economic transformation in South Africa?

Vrinda Chopra analyses whether the increasing focus on small, medium and microenterprises is a viable way of reducing inequality in South Africa

A Study of QTd as an indicator of Cardiac Autonomic Neuropathy in Type 2 Diabetes Mellitus

INTRODUCTION: Cardiac Autonomic Neuropathy (CAN) is often overlooked both in diagnosis and treatment simply because there is no widely accepted single approach to its diagnosis. Currently, Cardiovascular autonomic reflex tests (CART) are the gold standard for diagnosing CAN in persons with DM .It include four tests: (i) heart rate variation to deep breathing (ii) heart rate variation to Valsalva, (iii.) heart rate response to standing (30:15), and (iv) orthostatic hypotension. But these tests are cumbersome and not easy to perform in every patient. Therefore, there is a need of simple, non-invasive bed side test to detect early autonomic involvement in diabetes. AIMS AND OBJECTIVES: 1. To determine QTc maximum, QTc mean, QTc minimum QTc dispersion in Type2 diabetic patients. 2. Comparison of QTc maximum, QTc minimum, QTc dispersion, QTc mean in both study group and control group. 3. To study the significance of QTd as an indicator of CAN in Type 2 Diabetes mellitus. MATERIALS&METHOD: The study was conducted among patients from General Medicine wards of Government Rajaji Hospital, Madurai during the period of February 2016 to July 2016. The study included 100 cases of diabetes and 100 age and sex matched controls. Subjects believed to fulfill all eligibility criteria, and none of the exclusion criteria were included in the study. METHODOLOGY: A previously designed proforma was used to collect the demographic data, history and clinical details of the patients. A battery of five autonomic function tests are done in all cases to assess CAN. A score of 0-2 is assigned to each test. Based on the score obtained from the test, patients are divided in to three groups-severe, early and no CAN. A 12 lead ECG is taken after 10 minutes rest in all patients at 50 mm/second speed. RR interval, heart rate, QTc interval, QTc maximum, QTc minimum and QTc dispersion are calculated from the ECG. Comparisons of heart rate, QTc mean, QTc max, QTc min, QTc dispersion are made in various groups and controls and significance assessed by Students t test. Relation between age, sex, and autonomic neuropathy are assessed by Pearson correlation test. RESULTS: The average age for study group was 54 years. Among the 100 patients studied 55 were males and 45 females. Among the cases studied 62 had CAN .Of these 62, 44 had Grade 2(severe) CAN, 18 had Grade1(early) CAN .Mean heart rate was found to be high in diabetic patients compared to controls .Among the cases the heart rate was higher in those with severe CAN . QT mean ,QT minimum, QT maximum, QT dispersion was significantly more in patients with CAN than those without CAN and controls. Among those with CAN these were found to be significantly more in patients with Grade 2 CAN than those with Grade 1 CAN. CONCLUSION: Diabetics with CAN had significantly higher QTc mean, QTc maximum ,QTc minimum, QTc dispersion values compared to diabetics without CAN and controls

Simulating Large-Scale Microscopic Traffic Data

Traffic situations are continuous, uncertain, highly dynamic and partially observable, and they affect the day-to-day lives of people in a society. A worthwhile endeavor is to develop algorithms that can predict abnormal traffic situations by exploiting data from the myriad of sensors on the streets, in vehicles and in smartphones, leading to smoother flow of traffic. Unfortunately, the large volumes of microscopic (i.e. individual vehicle-level) data required for developing statistical/machine learning algorithms cannot be collected from the field by the public. The data collected by transportation agencies is either macroscopic or not widely available. In this thesis, a framework is developed for simulating large-scale traffic data using a microscopic simulation model and limited real-world data. Five kinds of sensors are simulated: inductor loop detector, lane area detector, multi-entry multi-exit detector, Bluetooth, and edgebased traffic measure. Data is simulated using this framework from multiple sensors over an area covering Montgomery County and Prince George County in Washington DC for 720 hours (30 days). The synthesized data is validated with respect to real-world data for volume and speed. Widely-used classifiers are used to recognize eight traffic events, namely Collision, Disabled Vehicle, Emergency Roadwork, Injuries Involved, Obstructions, Road Maintenance Operations, Traffic Signal Not Working and with no events in the synthesized dataset with high accuracy. Given limited real-world microscopic traffic data from a particular area, this framework is the first of its kind that can simulate data from multiple kinds of sensors over a very long duration with high-fidelity to the given data

Quebec’s Bill 62: Legislating Difference

On October 18, 2017, Bill 62, whose full English title is “An Act to foster adherence to state religious neutrality and, in particular, to provide a framework for religious accommodation requests in certain bodies,” came into force in the Canadian province of Quebec. In effect, Bill 62 prohibits niqab-wearing women from giving or receiving public services. It reflects anxiety about religious minorities’ illiberal practices and discomfort with the accommodation of religious difference—the “hypervisibility” of Islamic differences in particular. Bill 62 constructs the multiculturalism and reasonable accommodation debates in a way that erases race and replaces it with culture and religion. In turn, the politics of reasonable accommodation in Quebec conceptualize racialized minorities as threats to Canadian and Quebecois national identity and casts them aside as illegitimate citizens unless they assimilate. State multiculturalism and the reasonable accommodation discourse reinforce the racial status quo by setting the terms of the debate and the limits of tolerance—the “epistemic conditions” that dissuade a close scrutiny of the state’s management of diversity. This Article offers a close analysis of Bill 62 by following a framework that is built on four pillars: (1) interrogating secularism and state neutrality; (2) foregrounding structural difference to achieve systemic equality; (3) theorizing reasonable accommodation; and (4) combatting persisting colonial and Orientalist tropes of racialized Muslim women