Carbon and Boron Nitride Nanocomposites for Electrically and/or Thermally Conductive Materials

Herein, we report research centered on the use of single walled carbon nanotubes (SWNTs) for their electrical conductivity (EC) , or more specifically the harvesting of metallic-SWNTs for their extremely high EC, and on the exploitation of carbon and boron nitride nano-fillers for polymeric composites of high thermal conductivity (TC). SWNTs as produced are a mixture of both metallic and semiconducting components , which are distinctively different in electrical conductivity and many other aspects. Thus post-production separation of -SWNTs from their mixtures in the as-produced samples is necessary. As a result, my dissertation is formatted as such: the first chapter is a detailed review of Metallic Single Walled Carbon Nanotubes for electrically conductive materials and devices; the second chapter is primarily focused on the separation of SWNTs into their respective metallic and semiconducting components using non-covalent functionalization and solubilization. The method exploits the selectivity between metallic- and semiconducting-SWNTs in their non-covalent interactions with planar aromatic molecules or moieties, which with the different solubility characteristics enable convenient solution-phase separation. Lastly, my focus will center on the development of lightweight composites to be utilized in two categories: one for ultra-high TC and the other for materials of high TC but no EC. Therefore, the development of such materials is highly dependent on the selection of nano-scale fillers and their configurations in various matrices and thus the interfacial properties. For example, those flexible composites of high TC consist of two components, one of those of extremely high TC (coupled), and the other of high TC but no EC (decoupled), which are both based on the use of GNs and BNNs as nanofillers, respectively. Hence, reported herein is the exploitation of various mechanisms that dictate TC and EC in nanocomposite materials to achieve a high TC/EC ratio

Integrating tuberculosis and HIV care in the primary care setting in South Africa.

BACKGROUND: In many countries including South Africa, the increasing human immunodeficiency virus (HIV) and tuberculosis (TB) epidemics have impacted significantly on already weakened public health services. This paper reviews the scope, process and performance of the HIV and TB services in a primary care setting where antiretroviral therapy is provided, in Khayelitsha, South Africa, in order to assess whether there is a need for some form of integration. METHODS: The scope and process of both services were assessed through observations of the service and individual and group interviews with key persons. The performance was assessed by examining the 2001-2002 reports from the health information system and clinical data. RESULTS: The TB service is programme oriented to the attainment of an 85% cure rate amongst smear-positive patients while the HIV service has a more holistic approach to the patient with HIV. The TB service is part of a well-established programme that is highly standardized. The HIV service is in the pilot phase. There is a heavy load at both services and there is large degree of cross-referral between the two services. There are lessons that can be learnt from each service. There is an overlap of activities, duplication of services and under-utilization of staff. There are missed opportunities for TB and HIV prevention, diagnosis and management. CONCLUSIONS: The study suggests that there may be benefits to integrating HIV and TB services. Constraints to this process are discussed

Optimal sizing of a wind-photovoltaic-battery hybrid renewable energy system considering socio-demographic factors

The sizing of a stand-alone wind-photovoltaic-battery hybrid renewable energy system (HRES) is greatly influenced by socio-demographic factors however, few studies have examined how socio-demographic factors, as borne out by different electrical usage patterns, influence the size of HRESs. This paper investigates how these factors influence the optimal sizing of a stand-alone HRES using a hybrid optimization method to match the available renewable energy with the demand. In this regard, different energy usage patterns resulting from users socio-demographic profile have been investigated and used for the optimal sizing of a HRES. The results show that the electricity usage profile of a site has a significant impact on the sizing and design of the system. Further, the results illustrate that one can design a system that meets the demand profiles resulting from socio-demographic factors with a minimum unmet load; however, by optimizing systems to the users socio-demographic profile, significant cost savings can be made

Unreality TV

Presents a discussion about the ethical challenges facing a psychologist asked to conduct interviews with potential contestants of a television reality show that places participants in a series of stressful and embarrassing activities. Response to the career-altering opportunity; General practice issues facing the psychologist; Public view on psychologists\u27 involvement with the media

Sustaining tuberculosis decline in the UK

The re-emergence of tuberculosis in England began in the late 1980s increasing to a peak in 2011; since then incidence has fallen throughout the UK, in both the UK and non-UK born population, including in children.1 After 4 consecutive years of declining incidence of tuberculosis, sustained progress is finally being made with a 30% decline between 2011 and 2015.1 However, tuberculosis incidence in the UK remains higher than in most other high-income European countries and more than four times higher than in the USA

Clostridium perfringens in London, July 2009: two weddings and an outbreak

Food poisoning outbreaks caused by Clostridium perfringens enterotoxin occur occasionally in Europe but have become less common in recent years. This paper presents the microbiological and epidemiological results of a large C. perfringens outbreak occurring simultaneously at two weddings that used the same caterer. The outbreak involved several London locations and required coordination across multiple agencies. A case-control study (n=134) was carried out to analyse possible associations between the food consumed and becoming ill. Food, environmental and stool samples were tested for common causative agents, including enterotoxigenic C. perfringens. The clinical presentation and the epidemiological findings were compatible with C. perfringens food poisoning and C. perfringens enterotoxin was detected in stool samples from two cases. The case-control study found statistically significant associations between becoming ill and eating either a specific chicken or lamb dish prepared by the same food handler of the implicated catering company. A rapid outbreak investigation with preliminary real-time results and the successful collaboration between the agencies and the caterer led to timely identification and rectification of the failures in the food handling practices

Recent TB transmission, clustering and predictors of large clusters in London, 2010-2012: results from first 3 years of universal MIRU-VNTR strain typing

BACKGROUND: The incidence of TB has doubled in the last 20 years in London. A better understanding of risk groups for recent transmission is required to effectively target interventions. We investigated the molecular epidemiological characteristics of TB cases to estimate the proportion of cases due to recent transmission, and identify predictors for belonging to a cluster. METHODS: The study population included all culture-positive TB cases in London residents, notified between January 2010 and December 2012, strain typed using 24-loci multiple interspersed repetitive units-variable number tandem repeats. Multivariable logistic regression analysis was performed to assess the risk factors for clustering using sociodemographic and clinical characteristics of cases and for cluster size based on the characteristics of the first two cases. RESULTS: There were 10 147 cases of which 5728 (57%) were culture confirmed and 4790 isolates (84%) were typed. 2194 (46%) were clustered in 570 clusters, and the estimated proportion attributable to recent transmission was 34%. Clustered cases were more likely to be UK born, have pulmonary TB, a previous diagnosis, a history of substance abuse or alcohol abuse and imprisonment, be of white, Indian, black-African or Caribbean ethnicity. The time between notification of the first two cases was more likely to be <90 days in large clusters. CONCLUSIONS: Up to a third of TB cases in London may be due to recent transmission. Resources should be directed to the timely investigation of clusters involving cases with risk factors, particularly those with a short period between the first two cases, to interrupt onward transmission of TB

Influence of regional-scale anthropogenic emissions on CO2 distributions over the western North Pacific

We report here airborne measurements of atmospheric CO2 over the western North Pacific during the March-April 2001 Transport and Chemical Evolution over the Pacific (TRACE-P) mission. The CO2 spatial distributions were notably influenced by cyclogenesis-triggered transport of regionally polluted continental air masses. Examination of the CO2 to C2H2/CO ratio indicated rapid outflow of combustion-related emissions in the free troposphere below 8 km. Although the highest CO2 mixing ratios were measured within the Pacific Rim region, enhancements were also observed further east over the open ocean at locations far removed from surface sources. Near the Asian continent, discrete plumes encountered within the planetary boundary layer contained up to 393 ppmv of CO2. Coincident enhancements in the mixing ratios of C2Cl4, C2H2, and C2H4 measured concurrently revealed combustion and industrial sources. To elucidate the source distributions of CO2, an emissions database for Asia was examined in conjunction with the chemistry and 5-day backward trajectories that revealed the WNW/W sector of northeast Asia was a major contributor to these pollution events. Comparisons of NOAA/CMDL and JMA surface data with measurements obtained aloft showed a strong latitudinal gradient that peaked between 35° and 40°N. We estimated a net CO2 flux from the Asian continent of approximately 13.93 Tg C day-1 for late winter/early spring with the majority of the export (79%) occurring in the lower free troposphere (2-8 km). The apportionment of the flux between anthropogenic and biospheric sources was estimated at 6.37 Tg C day-1 and 7.56 Tg C day-1, respectively

The Key Characteristics of Different Types of Employees: A Summary of Six Studies

Purpose – The purpose of this paper is, first, to summarize six studies which analyze the key characteristics of different types of employees. Three types of employees found in workplaces all over the world are identified as “Necessities,” “Commoners,” and “Parasites” and, second, to combine the results of these studies in order to identify the key traits and behaviors that characterize each type of worker across a variety of social and cultural settings. Design/methodology/approach – For starters, three types of employees are defined. First, a person is a Necessity if s/he is irreplaceable and critical to the functioning of an organization. Second, a Commoner is a person of normal ability and talent who has no significant impact on organizational processes. Last, Parasites are detrimental freeloaders who damage the functioning of an organization. To identify the principal characteristics of these three types of workers, a group of researchers led by the first author conducted six studies in which they collected survey data from undergraduate and graduate business students in the USA, India, Korea, Chile, and Japan. Findings – The authors note the points of commonality and difference across the data sets, and offer their thoughts on future research in the area. The perceptions of what characterizes really good workers (people of Necessity) and very bad workers (Parasites) appear to be the same in all five countries. The picture painted for the Commoner across all data sets, however, is not as clear-cut. Originality/value – The study described in this paper helps to explain both similarities and differences in employee characteristics between and among workers in different countries and cultures

WESTT (Workload, Error, Situational Awareness, Time and Teamwork): An analytical prototyping system for command and control

Modern developments in the use of information technology within command and control allow unprecedented scope for flexibility in the way teams deal with tasks. These developments, together with the increased recognition of the importance of knowledge management within teams present difficulties for the analyst in terms of evaluating the impacts of changes to task composition or team membership. In this paper an approach to this problem is presented that represents team behaviour in terms of three linked networks (representing task, social network structure and knowledge) within the integrative WESTT software tool. In addition, by automating analyses of workload and error based on the same data that generate the networks, WESTT allows the user to engage in the process of rapid and iterative “analytical prototyping”. For purposes of illustration an example of the use of this technique with regard to a simple tactical vignette is presented