The behaviour of free gold particles in a simulated flash flotation environment

A reliable laboratory method to characterize the response of free gold particles to flash flotation conditions has been developed. The test has been performed on free milling gold ores as well as synthetic ores, using either a gravity concentrate or gold powder as the gold source, to assess the floatability of gold particles. Trends in free gold flotation kinetics, as well as size and milling effects, were identified for gold recovery based on the different feed types, reagent dosages, and residence times. It was shown that the ultimate recoveries and kinetic trends of gold particles from the gravity concentrate could be enhanced with increased dosage of collector, potassium amyl xanthate. Interestingly, in comparison to gravity-recoverable gold, recovery from pure Au powders was better in collectorless flotation, and cumulative recovery decreased with higher levels of collector addition. Improved coarse particle recovery appeared linked to increased collector additions for both the gravity concentrate and the pure gold powders. In general, coarse gold particles demonstrated slower kinetic rates than the fine or intermediate components incomparable tests

Monitoring the hygrothermal and ventilation performance of retrofitted clay brick solid wall houses with internal insulation: Two UK case studies

This work assesses the hygrothermal and ventilation performance of two ‘hard-to-treat’ historic, clay brick, solid wall houses that are internally insulated. Retrofit A is a two bedroom bungalow with the addition of internal plasterboard and air cavity and Retrofit B is a 5 bedroom house with sheep wool, phenolic and plasterboard insulation. To evaluate the long term performance of the retrofit measures, the testing is carried out 7 and 8 years respectively after completion. The first part of the work investigates whole building hygrothermal performance, ventilation and internal conditions. It was found that both retrofits are operating below specification in regards to their ventilation performance. An in-situ performance based specification for mechanical ventilation via CO2 monitoring is proposed. The second part focuses on the hygrothermal behaviour of the clay brick wall assembly. Both presented high relative humidity within critical layers of the wall make up. In Retrofit A the wall thermal transmittance was found to be much higher than designed due to inappropriate construction detailing while Retrofit B showed excellent thermal performance and minimal effects of thermal bridging

Retrofit versus new-build house using life-cycle assessment

This paper reports the findings of research on the environmental performance of two case-study houses, a retrofit and new build. The retrofit was completed to a Passivhaus standard while the new build was completed to current Irish building regulations. Environmental performance of the retrofit and new build was measured using life-cycle assessments, examining the assembly, operational and end-of-life stage over life spans of 50 and 80 years. Using primary information, life-cycle assessment software and life-cycle assessment databases the environmental impacts of each stage were modelled. The operational stage of both case studies was found to be the source of the most significant environmental damage, followed by the assembly and the end-of-life stage respectively. The relative importance of the assembly and end-of-life stage decreased as the life span increased. It was found that the retrofit house studied outperformed the new build in the assembly and operational stage, whereas the new build performed better in the end-of-life stage; however, this is highly sensitive, depending on the standards to which both are completed. Operational energy savings pre- and post-retrofit were significant, indicating the future potential for adoption of high-quality retrofitting practices. </jats:p

Life cycle assessment of geopolymer concrete: A Malaysian context

An electrochemical fuel cell contains first and second monolithic electrically conducting flow field-bipolar plate assemblies arranged essentially parallel to each other such that an inside surface of the first bipolar separator plate is facing an inside surface of the second bipolar separator plate, wherein the bipolar separator plates are electrically and mechanically connected by intervening layers that are directly bonded to each other. The fuel cells can be stacked between endplates and supplied with hydrogen and oxygen to generate electric power. An air cooled condenser for use with a fuel cell stack is composed of a porous foam condensing element and a porous foam cooling element. The condenser can be placed by a fuel cell stack for cooling purposes.U

Effects of Vitamin D Supplementation on Cognitive and Emotional Functioning in Young Adults – A Randomised Controlled Trial

Background: Epidemiological research links vitamin D status to various brain-related outcomes. However, few trials examine whether supplementation can improve such outcomes and none have examined effects on cognition. This study examined whether Vitamin D supplementation led to improvements in diverse measures of cognitive and emotional functioning, and hypothesised that supplementation would lead to improvements in these outcomes compared to placebo

Responsible learning analytics: creating just, ethical, and caring

Ethical considerations and the values embedded in the design, development, deployment, and use of Learning Analytics (LA) systems have received considerable attention in recent years. Ethical frameworks, design guidelines, principles, checklists, and a code of practice have contributed a conceptual basis for focused discussions on ethics in LA. However, relatively little is known about how these different conceptual understandings of ethics work in practice. This half-day interactive workshop aims to provide participants with a space for information, dialogue, and collaboration around Responsible LA. The workshop will begin with a brief overview of Responsible LA. After that, the participants will present their cases drawing attention to the ethical considerations covered and not covered in LA practices. Following this, participants in groups will discuss the cases illustrating ethical tensions and create semantic categories to document such edge cases. The collected edge cases will be shared in a wiki or database. The workshop outcomes will help inform LA practitioners on ethical tensions that need to be discussed with care while highlighting places where more research work is required

Mycobacterium bovis genomics reveals transmission of infection between cattle and deer in Ireland

Control of bovine tuberculosis (bTB), caused by Mycobacterium bovis, in the Republic of Ireland costs €84 million each year. Badgers are recognised as being a wildlife source for M. bovis infection of cattle. Deer are thought to act as spillover hosts for infection; however, population density is recognised as an important driver in shifting their epidemiological role, and deer populations across the country have been increasing in density and range. County Wicklow represents one specific area in the Republic of Ireland that has had consistently high bTB prevalence for over a decade, despite control operations in both cattle and badgers. The area is also known to have a high density of deer. Our research used whole genome sequencing of M. bovis sourced from infected cattle, deer, and badgers in County Wicklow to evaluate whether the epidemiological role of deer could have shifted from spillover host to source. Our analyses reveal that cattle and deer share highly similar M. bovis strains suggesting that transmission between these species is occurring in the area. In addition, the high level of diversity observed in the sampled deer population suggests deer may be acting as a source of infection for local cattle populations. These findings have important implications for the control and ultimate eradication of bTB in Ireland

Evaluating the feasibility of implementing a Telesleep pilot program using two-tiered external facilitation

Background: Obstructive sleep apnea (OSA) can negatively impact patients' health status and outcomes. Positive airway pressure (PAP) reverses airway obstruction and may reduce the risk of adverse outcomes. Remote monitoring of PAP (as opposed to in-person visits) may improve access to sleep medicine services. This study aimed to evaluate the feasibility of implementing a clinical program that delivers treatment for OSA through PAP remote monitoring using external facilitation as an implementation strategy. Methods: Participants included patients with OSA at a Veteran Affairs Medical Center (VAMC). PAP adherence and clinical disease severity on treatment (measured by the apnea hypopnea index [AHI]) were the preliminary effectiveness outcomes across two delivery models: usual care (in-person) and Telehealth nurse-delivered remote monitoring. We also assessed visit duration and travel distance. A prospective, mixed-methods evaluation examined the two-tiered external facilitation implementation strategy. Results: The pilot project included N = 52 usual care patients and N = 38 Telehealth nurse-delivered remote monitoring patients. PAP adherence and disease severity were similar across the delivery modalities. However, remote monitoring visits were 50% shorter than in-person visits and saved a mean of 72 miles of travel (median = 45.6, SD = 59.0, mode = 17.8, range 5.4-220). A total of 62 interviews were conducted during implementation with a purposive sample of 12 clinical staff involved in program implementation. Weekly external facilitation delivered to both front-line staff and supervisory physicians was necessary to ensure patient enrollment and treatment. Synchronized, "two-tiered" facilitation at the executive and coordinator levels proved crucial to developing the clinical and administrative infrastructure to support a PAP remote monitoring program and to overcome implementation barriers. Conclusions: Remote PAP monitoring had similar efficacy to in-person PAP services in this Veteran population. Although external facilitation is a widely-recognized implementation strategy in quality improvement projects, less is known about how multiple facilitators work together to help implement complex programs. Two-tiered facilitation offers a model well-suited to programs where innovations span disciplines, disrupt professional hierarchies (such as those between service chiefs, clinicians, and technicians) and bring together providers who do not know each other, yet must collaborate to improve access to care