Patterns of Women's Enrolment in University Mathematics, Engineering and Computer Science in Canada, 1972-1995

Efforts to ensure equity for women in scientific and technological disciplines must precede, or at least accompany, efforts to persuade them to pursue these studies. To achieve gender equity in these disciplines, factors discouraging women from full participation in them should be removed. Many psychological, sociological and institutional factors have been identified as contributors to the under-representation of women in these fields. For the aim of understanding and appraising these factors, this study offers a factual characterization of women's enrolment levels in mathematics, engineering, and computer science in Canadian universities and the change in these levels over the period 1972 to 1995. Findings indicate that patterns of women's enrolment in these three dis- ciplines are vastly different, a fact which suggests that factors specific to each discipline interact with and modify the effects of the more general sociological and psychological obstacles impeding women's participa- tion in them.Tout effort qui vise à assurer l'équité féminine dans les disciplines scientifiques et technologiques doit précéder, ou du moins accompagner, tout effort employé pour persuader ces femmes à poursuivre leurs études dans ces domaines. Pour que l'équité se réalise pleinement à travers ces disciplines, il est important que tout facteur qui puisse décourager la pleine participation féminine dans ces disciplines soit éliminé. Plusieurs éléments psychologiques, sociologiques et institutionnels ont déjà été identifiés comme étant des facteurs contribuant à la faible représentation féminine dans ces disciplines. Cette étude offre une représentation factuelle des niveaux d'inscriptions féminines ainsi que les changements dans ces niveaux au cours de la période partant de 1972 à 1995. Les résultats de cette étude démontrent de vastes différences entre les niveaux d'inscriptions féminines de discipline en discipline, ce qui suggère que des facteurs propres à chaque discipline s'entremêlent et modifient les aspects plus généraux des obstacles sociologiques et psychologiques qui empêchent la pleine participation féminine dans ces domaines

Design and simulation of an integrated process for biodiesel production from waste cooking oil using supercritical methanolysis

Non-catalytic transesterification has been recognised as an effective technique for biodiesel production. It has many advantages over conventional catalytic transesterification, where it eliminates the difficulties of catalysts preparation and separation. It also produces high biodiesel yield in shorter reaction time. However, it requires harsh operating conditions at high reaction temperature and pressure, in addition to using large excess of methanol. In an attempt to mitigate these problems, a process design/integration for biodiesel production has been performed. The process has been subjected to both mass and energy integration to minimise fresh methanol requirements and to minimise heating and cooling energies, respectively. A new graphical Pinch Analysis method has been used to evaluate the energy performance of a literature design for the current process. It has been subsequently used to develop an optimum heat exchanger network (HEN) for the process by matching of process streams. Also, the design made by using an automated commercial simulation (Aspen Energy Analyzer) has been evaluated using the same graphical method. The produced HEN design from graphical method has achieved the optimum results with respect to energy targets

Valorisation of high acid value waste cooking oil into biodiesel using supercritical methanolysis: Experimental assessment and statistical optimisation on typical Egyptian feedstock

In this study, valorisation of high acid value waste cooking oil into biodiesel has been investigated. Non-catalytic transesterification using supercritical methanol has been used for biodiesel production. Four controllable independent process variables have been considered for analysis including methanol to oil (M:O) molar ratio, temperature, pressure and time. Uncommon effects of process variables on the reaction responses, e.g. biodiesel and glycerol yields, have been observed and extensively discussed. Response surface methodology (RSM) via Central Composite Design (CCD) has been used to analyse the effect of the process variables and their interactions on the reaction responses. A quadratic model for each response has been developed representing the interrelationships between process variables and responses. Analysis of Variance (ANOVA) has been used to verify the significance effect of each process variable and their interactions on reaction responses. Optimal reaction conditions have been predicted using RSM for 98% and 2.05% of biodiesel and glycerol yields, respectively at 25:1 M:O molar ratio, 265oC temperature, 110 bar pressure and 20 minutes reaction time. The predicted optimal conditions have been validated experimentally resulting in 98.82% biodiesel yield, representing 0.83% relative error. The quality of the produced biodiesel showed excellent agreement with the European biodiesel standard (EN14214)

Systematic multivariate optimization of biodiesel synthesis from high acid value waste cooking oil: A response surface methodology approach

Biodiesel has received increasing attention as a green renewable alternative fuel for petroleum diesel. It is synthesised from renewable resources including vegetable oils, animal fats and microalgal cells. Recently, biodiesel production using supercritical technology has been considered as a viable production technique for different feedstocks with potential industrial application. Supercritical production of biodiesel has many advantages over conventional catalysed methods e.g. it neither requires catalyst nor washing water, requires shorter reaction time, provides higher biodiesel yield and produces purer glycerol and purer methanol without involving any dehydration processes. However, the high process energy consumption due to harsh operating conditions is the main obstacle for industrial scale-up of the process. In the present study, a multivariate optimisation technique has been employed for optimising the supercritical production of biodiesel from high acid value waste cooking oil (WCO). The feedstock has been selected as it is widely available from various food industries. The following process variables have been analysed for optimisation e.g. methanol to oil (M:O) molar ratio, temperature, pressure and reaction time. Different responses have been considered for the reaction including overall biodiesel yield, free fatty acids (FFAs) conversion and the conversion of different triglycerides. Response surface methodology (RSM) using central composite design (CCD) have been used to design the experiments and to optimise the process. A quadratic mathematical regression model has been developed for each response function in the reaction variables. The influence of reaction variables and their interactions on the reaction responses have been extensively investigated. The significant process variables have been identified using analysis of variance (ANOVA). Highly significant influences of reaction temperature, pressure and time have been observed. In addition, the interactions between different reaction variables have shown significant effect on reaction responses. The optimum conditions have been identified at M:O molar ratio of 25:1, 266oC reaction temperature and 110 bar pressure within 20 min of reaction time. Finally, the quality of the produced biodiesel showed excellent agreement with the European biodiesel standard (EN14214)

Supercritical methanolysis of waste cooking oil for biodiesel synthesis: Experimental and simulation assessments

Esterification/transesterification two steps process is considered as the most widely used technology for biodiesel synthesis from waste cooking oil (WCO). However, this technology is currently explored in a single step process using supercritical technology due to its higher biodiesel yield and shorter reaction time. This paper presents experimental and simulation study of biodiesel production from high acid value WCO using supercritical methanolysis. The influences of four reaction parameters on biodiesel production including methanol to oil (M:O) molar ratio, temperature, pressure and time have been investigated. Response surface methodology (RSM) has been used to develop an empirical regression equation representing reaction variables function in response variable. Analysis of variance (ANOVA) has been used to examine the accuracy of the predicted model. Optimisation of reaction variables has been performed to maximise biodiesel production. The optimal conditions for 99.1% and 97.2% overall conversions of triglycerides and free fatty acids (FFA), respectively have been reported at 27.2:1 M:O molar ratio, 257oC temperature, 110 bar pressure and 17 min reaction time . A commercial simulation software (Aspen HYSYS) has been used to design and simulate the production process. The reaction has been simulated using the developed kinetic data at the concluded optimal conditions. A comparative analysis has been performed for results obtained experimentally, numerically and from simulation

ASD, Anophthalmia and Aicardi Syndrome

Aicardi syndrome is a rare genetic disorder, X linked dominant; the syndrome is almost exclusively seen in females. It is characterized by classic triad of agenesis of corpus collosum, infantile spasm, and chorioretinal lacune. We report a case of this rare disorder, two and half month old female child who presented with frequent episodes of seizures and multiple congenital anomalies. Examination revealed microcephaly, anophthalmia, cleft lip and palate and atrial septal defect (ASD). MRI revealed agenesis of corpus callosum and dilated ventricular system. In this paper we present a case of Aicardi Syndrome associated with anophthalmia and ASD which were not reported before. She was put on clonazepam and was having a good seizure control

A comparative structural characterisation of different lignin biomass

This study focuses on the structural characterisation techniques of lignin, which is the most abundant component in biomass and commonly produced as residual product in pulp mills industry. It is inexpensive, non-toxic and biodegradable. Four different lignins have been selected for this study including Alcell lignin, Kraft lignin and two milled wood lignins (MWL) derived from coniferous trees (softwoods) and deciduous trees (hardwood). Fourier transform infrared (FTIR) spectroscopy analysis has been performed on all four types of lignin to identify the functional groups present in the lignin structure. The results have indicated that Alcell lignin consists of more desirable functional groups than Kraft lignin with higher phenolic, carbonyl and aromatic groups. Elemental analysis has been performed to examine the carbon and hydrogen content. The elemental analysis results indicates that MWL contain more hydrogen and carbon in comparison to other two commercial lignins. Heating values have been investigated in terms of higher heating value (HHV) and lower heating value (LHV). The lowest values of HHV and LHV have been reported for Kraft lignin due to its condensed structure. The differential thermogravimetry (DTG) analysis have been performed, which determines the maximum degradation temperature of the lignins. The start and maximum degradation temperature for each lignin help to set the pyrolysis temperature of the lignin for bio-oil production. Components that have been observed via Py-GC-MS analysis have indicated that degradation of bonds has led to the formation of three main structural units of lignin known as guaiacyl (G), syringyl (S) and p-hydroxyphenyl propane (p-H)–type. The results indicate that the Py-GC-MS analysis of MWL have higher aromatic components in comparison to the commercially available lignins

Reduced axonal diameter of peripheral nerve fibres in a mouse model of Rett syndrome

Rett syndrome (RTT) is a neurological disorder characterized by motor and cognitive impairment, autonomic dysfunction and a loss of purposeful hand skills. In the majority of cases, typical RTT is caused by de novo mutations in the X-linked gene, MECP2. Alterations in the structure and function of neurons within the central nervous system of RTT patients and Mecp2-null mouse models are well established. In contrast, few studies have investigated the effects of MeCP2-deficiency on peripheral nerves. In this study, we conducted detailed morphometric as well as functional analysis of the sciatic nerves of symptomatic adult female Mecp2+/- mice. We observed a significant reduction in the mean diameter of myelinated nerve fibers in Mecp2+/- mice. In myelinated fibers, mitochondrial densities per unit area of axoplasm were significantly altered in Mecp2+/- mice. However, conduction properties of the sciatic nerve of Mecp2 knockout mice were not different from control. These subtle changes in myelinated peripheral nerve fibers in heterozygous Mecp2 knockout mice could potentially explain some RTT phenotypes

Selected environmental factors associated with farm and farm home accidents in Missouri

Digitized 2007 AES.Includes bibliographical references (pages 60-61)