935 research outputs found
Energy Saving in Spirit Distillation
A simplified continuous wine spirit distillation plant was designed with the aim of saving energy, constructed and subsequently tested under full operational conditions. Duplication of the purification processes encountered in 6-column still operation was eliminated and the number of separate distillation columns reduced from six to four. The excellent separation of the alcohol from the impurities, achieved in a spacious purification column through adequate dilution of alcohol with water, is one of the outstanding characteristics of the adapted design. In addition, facilities for continuous caustic soda treatment of the impurities drastically reduced the percentage of feints. During distillation a continuous production of high quality spirit, with the still operating at 99% efficiency, was achieved. Distillation of inferior quality wine had no adverse effect on the quality of the distillate. Losses were minimal and steam consumption was reduced from 6,9 kg/L Absolute Alcohol, to 4,9 kg/LAA produced. The percentage feints requiring redistillation was reduced from ca. 20% to 1,0%
Sustainable safety volunteerism in the Strand, Western Cape: Volunteer identity, motivation and socio-organisational experiences
There is a growing recognition of the relevance and even centrality of volunteerism to adequate collective responses to poverty, housing and the promotion of human rights and, more recently, safety. Volunteerism by members of poor global South communities within their own communities has, however, remained relatively neglected and undescribed. This study explored the motivations, benefits and socio-organisational experiences that a group of volunteers reported as a result of their participation in a safety-promotion project in two under-resourced communities in the Strand, in the Western Cape, South Africa. The focus of this safety-promotion project was to enhance women’s safety and health and to reduce risks of injury and violence through the implementation of safety-promotion strategies that target the prevention of priority injuries, particularly violence, traffic injury and burns. The study used a qualitative approach and is based on the completion of questionnaires and focus group discussions with volunteers and project staff. Data analysis involved the thematic analysis of the written responses by 28 volunteers and 4 project staff to a questionnaire comprising open-ended and focused questions that explored their experiences of volunteerism. The study also involved the analysis of the transcriptions of two focus group discussions subsequently held with these volunteers to clarify, further develop and verify emerging themes. The volunteers identified both self-oriented and socially altruistic motivations and benefits. These volunteers highlighted a hope and desire to advance social change and promote safety within their communities. Volunteer experiences reflected their enthusiasm to enhance both the human and social capital of their communities simultaneously. This study highlighted the development of a volunteer identity as a necessary component for the implementation of a sustainable, volunteer-based safety-promotion project.Keywords: Volunteerism, safety, identity, motivation, experience
Mobile Malware Implications for IT Management
Since the turn of the century malicious software, called malware, has been generated to infect not only computer systems but also ‘smart’ mobile phones. This malicious code is designed specifically to infect the mobile devices and disrupt the operation of the device or to send messages or make calls, resulting in financial loss to the user. The paper analyses trends in mobile malware from the listings of the malware descriptions. These trends show the increasing severity of the mobile malware problem, the introduction of new malware types, and the changing focus on the malware objectives; predictions of possible future trends are made. The implications of these trends for organisational management are discussed, and possible countermeasures to the risks are suggested
Assessment of factors that impact on the viability of contract farming: A case study of maize and soya beans in Mashonaland West and central provinces in Zimbabwe
This research analyses factors that affect the viability of contract farming in the Zimbabwean maize and soya sector. The objective was to analyse how sustainability factors (social, ethical, environmental and economic factors) were integrated to ensure the viability and sustainability of contract ventures. A sample of 70 farmers and 4 contracting firms involved in the contract farming production of maize and soya were used. A questionnaire survey and focus group interviews were used as data gathering tools. Quantitative and qualitative data analysis techniques were used and a probit regression model was applied to identify the factors that impacts significantly on the viability of the enterprises. The farmer’s scale, years of experience, availability of inputs, crop grown, production area and access to finances were all identified as the significant factors affecting contract farming viability. It was recommended that farmers refrain from side marketing and contractors stick to contractual agreements in terms of payments and timely provision of inputs.Keywords: contract farming; viability; sustainabilit
The prevalence of underweight, overweight and obesity in a multiracial group of urban adolescent schoolchildren in the Cape Metropole area of Cape Town
Objective: The objective was to determine the prevalence of underweight, overweight and obesity in high school learners in the Cape Town area.Design: A cross-sectional study was conducted.Setting: High schools in the Cape Metropole Area of the Western Cape.Subjects: A complex cluster sampling procedure was followed. Thirty-six students per school were selected from each randomly selected school. Thirteen- to 18-year-old pupils were eligible for inclusion.Outcome measures: Height and weight measurements.Results: The sample comprised 689 students. There were considerably more underweight adolescent boys than adolescent girls (17.3% boys to 9.9% girls), and double the frequency of overweight adolescent girls than adolescent boys (7.7% girls to 3.5% boys). The 14-year-old boys had the highest prevalence of underweight (55.2%), and the 17-year-old girls the highest prevalence of overweight (22%). The highest prevalence of obesity was found in 15-year-old boys (11.1%), who also demonstrated a relatively high prevalence of underweight (30.2%).Conclusion: This study reported on a substantial percentage of underweight adolescents (27.1%). Noteworthy levels of overweight and obesity in adolescent girls added to the substantial prevalence of underweight in adolescent boys. Africa has enough to contend with in respect of transmissible diseases, without additional lifestyle-based health burdens
Strange Particle Production Via The Weak Interaction
The differential cross sections for the neutrino-induced weak charged current
production of strange particles in the threshold energy region are presented.
The general representation of the weak hadronic current is newly developed in
terms of eighteen unknown invariant amplitudes to parametrize the hadron
vertex. The Born term approximation is used for the numerical calculations in
the framework of the Cabibbo theory and SU(3) symmetry. For unpolarized octet
baryons four processes are investigated, whereas in the case of polarized
baryons only one process is chosen to study the sensitivity of the differential
cross section to the various polarizations of the initial state nucleon and the
final state hyperon.Comment: This paper was originally submitted to Physical Review C and
published on 30 August, 201
Reconciliation as the functional integration of complex systems
Reconciliation is usually seen in� connection with the relationships between God and his people, and the mutual relationships between people, especially believers in Christ. In Col 1, however, Paul relates reconciliation to all things in heaven and on earth. The implications of this statement for the life and work of the church and her members need further reflection. In this article, attention is given to the dysfunctional interactions between socio-cultural, ecological, economical, political and other systems in the Southern African context. These dysfunctional interactions cause widespread poverty, ecological degradation and social disruption. Church members can see it as their calling to work for the functional integration of these systems, in their own lifestyles as well as in society in general, in order to promote the wellbeing of society
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Sensitivity of resolved and parameterized surface drag to changes in resolution and parameterization
The relative contribution of resolved and parameterized surface drag towards balancing the atmospheric angular momentum flux convergence (AMFC), and their sensitivity to horizontal resolution and parameterization, are investigated in an atmospheric model. This sensitivity can be difficult to elucidate in free-running climate models, in which the AMFC varies with changing climatologies and, as a result, the relative contributions of surface terms balancing the AMFC also vary. While the sensitivity question has previously been addressed using short-range forecasts, we demonstrate that a nudging framework is an effective method for constraining the AMFC. The Met Office Unified Model is integrated at three horizontal resolutions ranging from 130 km (N96) to 25 km (N512) while relaxing the model’s wind and temperature fields towards the ERAinterim reanalysis within the altitude regions of maximum AMFC. This method is validated against short range forecasts and good agreement is found. These experiments
are then used to assess the fidelity of the exchange between parameterized and resolved orographic torques with changes in horizontal resolution. Although the parameterized
orographic torque reduces substantially with increasing horizontal resolution, there is little change in resolved orographic torque over 20N to 50N. The tendencies produced
by the nudging routine indicate that the additional drag at lower horizontal resolution is excessive. When parameterized orographic blocking is removed at the coarsest of these resolutions, there is a lack of compensation, and even compensation of the opposite
sense, by the boundary layer and resolved torques which is particularly pronounced over 20N to 50N. This study demonstrates that there is strong sensitivity in the
behaviour of the resolved and parameterized surface drag over this region
A thermodynamic model for comparing thermal energy storage system to electrochemical, chemical, and mechanical energy storage technologies
Paper presented to the 3rd Southern African Solar Energy Conference, South Africa, 11-13 May, 2015.This paper presents a novel methodology for comparing
thermal energy storage to electrochemical, chemical, and
mechanical energy storage technologies. The machination of
this model is hinged on the development of a round trip
efficiency formulation for these systems. The charging and
discharging processes of compressed air energy storage,
flywheel energy storage, fuel cells, and batteries are well
understood and defined from a physics standpoint in the context
of comparing these systems. However, the challenge lays in
comparing the charging process of these systems with the
charging process of thermal energy storage systems for
concentrating solar power plants (CSP). The source of energy
for all these systems is electrical energy except for the CSP
plant where the input is thermal energy. In essence, the round
trip efficiency for all these systems should be in the form of the
ratio of electrical output to electrical input. This paper also
presents the thermodynamic modelling equations including the
estimation of losses for a CSP plant specifically in terms of the
receiver, heat exchanger, storage system, and power block. The
round trip efficiency and the levelized cost of energy (LCOE)
are the metrics used for comparison purposes. The results from
the modelling are compared with solar power plants in
operation and literature. The crux of this modelling can be
regarded as a platform for the generation of a thermal energy
storage roadmap cocooned in a comprehensive energy storage
roadmap from a system of systems perspective.dc201
INFORMATION-BASED CONFLICT IN AFRICA
For a long time, the African continent was regarded as the ‘Dark Continent’.
The rapid assimilation of information technologies into the African economies has
placed Africa firmly on a trajectory that will see it compete and integrate with the
developed world. As nations and organisations become more information-centric, it
is natural that conflicts and competition amongst the various nations or organisations
will become increasingly information-based. In this article, the authors reflect upon
information-based conflict in Africa. Areas of information conflict that are discussed
include censorship, communications intercepts, the use of information and
communications to instigate violence and uprisings, and the possibility of cyberwarfare.
The article shows that the use of technology to conduct information conflict
in Africa is prevalent, and that it is likely to increase
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