Matter Wave Scattering from Ultracold Atoms in an Optical Lattice

We study matter wave scattering from an ultracold, many body atomic system trapped in an optical lattice. We determine the angular cross section that a matter wave probe sees and show that it is strongly affected by the many body phase, superfluid or Mott insulator, of the target lattice. We determine these cross sections analytically in the first Born approximation, and we examine the variation at intermediate points in the phase transition by numerically diagonalizing the Bose Hubbard Hamiltonian for a small lattice. We show that matter wave scattering offers a convenient method for non-destructively probing the quantum many body phase transition of atoms in an optical lattice.Comment: 4 pages, 2 figure

Over ‘sexed’ regulation and the disregarded worker: an overview of the impact of sexual entertainment policy on lap-dancing club workers

In England and Wales, with the introduction of Section 27 of the Policing and Crime Act 2009, lap-dancing clubs can now be licensed as Sexual Entertainment Venues. This article considers such, offering a critique of Section 27, arguing that this legislation is not evidence-based, with lap-dancing policy, like other sex-work policies, often associated with crime, deviance and immorality. Furthermore, it is argued that sex-work policies are gradually being homogenised as well as increasingly criminalised. Other criticisms relate to various licensing loopholes which lead to some striptease venues remaining unlicensed and unregulated, potentially impacting on the welfare of erotic dancers. In addition, restrictions on the numbers of lap-dancing venues may exacerbate dancer unemployment, drawing these women into poverty. Finally, The Policing and Crime Act reflects how the political focus is being directed away from the exploitation of workers, on to issues relating to crime and deviance, despite limited evidence to support this focus

Manifold Learning with Tensorial Network Laplacians

The interdisciplinary field of machine learning studies algorithms in which functionality is dependent on data sets. This data is often treated as a matrix, and a variety of mathematical methods have been developed to glean information from this data structure such as matrix decomposition. The Laplacian matrix, for example, is commonly used to reconstruct networks, and the eigenpairs of this matrix are used in matrix decomposition. Moreover, concepts such as SVD matrix factorization are closely connected to manifold learning, a subfield of machine learning that assumes the observed data lie on a low-dimensional manifold embedded in a higher-dimensional space. Since many data sets have natural higher dimensions, tensor methods are being developed to deal with big data more efficiently. This thesis builds on these ideas by exploring how matrix methods can be extended to data presented as tensors rather than simply as ordinary vectors

An investigation into the state of environmental education and the use of technology in environmental education in Gauteng, South Africa

Abstract : Since the Industrial Revolution, humankind has consumed and used the earth’s resources for its own gain, but at the expense of the earth’s biosphere (Maluleke, 2005; Govender, 2011). Such impacts did not go unnoticed within the realms of education. With the roots of Environmental Education can be traced back to the 18th century when Jean-Jacques Rousseau identified the importance of Environmental Education in that it is a learning area that focuses on the environment (Eneji et al., 2017). EE gained a significant boost in the 1960s and 1970s and gained a global platform in 1972. In 1972, Stockholm, hosted the United Nations Conference on the Human Environment, from which emanated a declaration to the effect that EE should be imperative as a tool to ‘address global environmental problems’ (Eneji et al., 2017). Since the 1970s, there have been significant advances in technology: from advances in automation to the use of mobile cellular devices and computers that have become exponentially more efficient and mobile. In fact, the list of types of technologies which have been developed since the 1970s is endless (Blažek et al., 2017). They have had an impact on almost every economic sector of the globe, including the education sector (Courville, 2011). The marriage of technology and EE is a perfect tool to enhance the latter. However, the implementation of both within the schooling system is often notably slow, as in South Africa. In line with this, the state of environmental education and how technology is used for it is largely unknown within South Africa. In line with this, this study investigates the state of Environmental Education and the use of technology in Environmental Education in the Further Education and Training (FET) phase presented by Gauteng secondary schools of South Africa. For which data was collected from educators’ utilising a questionnaire survey and was analysed by means of a SWOT analysis. The study found that similar challenges are faced in the implementation of both EE and technologies such as GIS and ICTs into the school systems in South Africa as are faced in countries around the world including South Korea and Tanzania. With the largest barrier to their implementation being a lack of access to resources. However, respondents of the study have largely embraced EE and the potential it has in creating environmentally literate citizens.M.Sc. (Environmental Management

Leadership’s Role in Curbing Law Enforcement Suicide

The purpose of this research is to explore what role leadership plays in curbing law enforcement suicide. Suicide has become a prevalent problem within the law enforcement community, and this research sets out to establish a foundation of the problem and identify possible causes for this trend. Research has established the seriousness of the problem. Several studies and articles point to the necessary and critical role law enforcement leadership needs to play in order to address this issue. Specifically, leadership needs to embrace the concept of organization-wide change by making the issue of suicide a priority. Most importantly, leaders must prioritize the creation and adoption of training and prevention programs with a heavy focus on intervention

Behind at the Starting Line: Poverty Among Hispanic Infants

In this brief, authors Daniel Lichter, Scott Sanders, and Kenneth Johnson examine the economic circumstances of Hispanic infants using the Census Bureau’s American Community Survey annual microdata files from 2006 through 2010. They report that a disproportionate share of Hispanic infants start life’s race behind the starting line, poor and disadvantaged—an important finding because the proportion of all U.S. births that are Hispanic is growing rapidly. The poverty risk is especially high among rural Hispanic infants and those in new destinations. Despite higher poverty risks, Hispanic infants receive less governmental assistance. High Hispanic infant poverty has immediate and long-term consequences for infants and the nation. Failing to invest in families and children now has long-term consequences because early childhood poverty tends to set into motion a series of lifecycle disadvantages (such as insufficient parenting, bad neighborhoods, underfunded schools, and poor health care) that greatly increases the likelihood of poverty in adulthood. The authors conclude that whether today’s Hispanic children will assimilate into America’s economic mainstream is an open question, but the Hispanic infants who will help reshape America’s future require public policy attention now

Laser Spectroscopy of Wire-Like Molecules

Cavity-enhanced Laser-Induced Fluorescence With the incorporation of a new optic mount and focussing lens a cavity ring-down set-up was altered to collect fluorescence signal from molecules seeded in a molecular beam. Running both the CRDS and fluorescence measurements simultaneously produced a technique with significantly enhanced sensitivity compared to either of the two individual methods. Preliminary analysis with SO2 and a selection of polyaromatic molecules point to the method been best suited for measuring the fluorescence spectra of fast fluorescence lifetime (< 1 ns) molecules and in confined environments i.e. molecular beams. This has been characterised using a known sample and also compared to the CRDS and fluorescence measurements ran as individual techniques. The method was found to increase the sensitivity of the current experimental set-up by two orders of magnitude. This was then applied in the analysis of two new molecular samples to obtain spectra for use in analysing the torsional motions within the molecule. Torsional Motion Analysis of 2,5-bis(phenylethynyl)thiophene Torsional motions in polyphenyls, potential molecular wires, are important in the charge carriage capability of the species. Using a combination of UV-cavity ring-down and fluorescence detection the absorption and photoexcitation spectra of 2,5-bis(phenylethynyl)thiophene were successfully measured. Using a simple cosine potential and simulation program the spectra were reproduced and were found to be close to the values determined in previous research on the two ring system tolane and 1,4-bis(phenylethynyl)benzene

Erythrocytes in multiple sclerosis: forgotten contributors to the pathophysiology?

Multiple sclerosis (MS) is an autoimmune disease characterised by lymphocytic infiltration of the central nervous system and subsequent destruction of myelin and axons. On the background of a genetic predisposition to autoimmunity, environmental triggers are assumed to initiate the disease. The majority of MS research has focused on the pathological involvement of lymphocytes and other immune cells, yet a paucity of attention has been given to erythrocytes, which may play an important role in MS pathology. The following review briefly summarises how erythrocytes may contribute to MS pathology through impaired antioxidant capacity and altered haemorheological features. The effect of disease-modifying therapies on erythrocytes is also reviewed. It may be important to further investigate erythrocytes in MS, as this could broaden the understanding of the pathological mechanisms of the disease, as well as potentially lead to the discovery of novel and innovative targets for future therapies

Design of Control System with Feedback Loop for a Pulsatile Pump

This paper describes the design and implementation of a closed-loop proportional, integral, differential (PID) control system for a custom in-house pulsatile pump apparatus for the University of Arkansas Biomedical Department. The control system is designed to control a MOONS’ PL34HD0L8500 hybrid stepper motor using a dual H-bridge motor driver network with four pulse-width modulated (PWM) inputs to drive a pulsatile pump apparatus at motor stepping frequencies up to 2kHz. The speed of the motor is controlled from a pressure profile transmitted from an external source over RS-232 communication that specifies the motor speed, number of datapoints, and an array of pressure data. Data will be measured from the pump using pressure, flow, and temperature sensors that will output analog data and be read to the control board using analog-to-digital converters (ADCs). A PID controller will be used to match the speed of the motor to the control data by calculating the error between the sensor outputs and the desired profile. The circuit board is separated into two sections for the control board and motor circuit to isolate the 68V and motor circuity from the rest of the control board circuitry. The control system circuitry was tested, and while the control board systems were found to be functional, the motor circuit was found inefficient due to the high L/R time constant of the motor, resulting in greatly reduced speed and torque. A new chopper driver design was proposed to solve this issue and simulations conducted through MATLAB Simulink to prove the feasibility of the design