Copper Indium Sulfide Quantum Dots for Light Selective Nanocomposite Thin Films and Solar Cell Applications

Nanotechnology is allowing the solar energy industry to advance at an accelerating rate, although new materials and processes are required for developing new types of solar cells. Similar to other industries, it is desirable to develop the most environmentally friendly and cost-effective solutions on how to make these next generation materials. Of these new materials, quantum dots (QDs) are of current scientific interest which provide record-breaking increases in efficiency and a new approach for harnessing solar radiation. However, most previous QD work has focused on lead or cadmium based materials, which are not earth friendly and have low thresholds in both California and European legislation. For this reason, this work examines the earth friendly and abundant materials Copper Indium Sulfide (CIS) QDs, i.e. CIS-QDs, which have favorable emission properties. These materials were prepared and examined for use in solar harvesting in photovoltaic (PV) devices. Copper Indium Sulfide (CIS) QDs were synthesized using three different synthesis techniques, then compared based on their optical and size-dependent properties. Two techniques followed a hydrothermal batch reaction process, referred to as hot injection (HI) and heat up (HU) techniques, that are differentiated by the time at which the sulfur component is added to the reaction medium. The third technique was based on a continuous microfluidic approach. Results showed that the QDs produced from the HU and HI methods have a chalcopyrite structure, with their optical properties being highly dependent on their size and elemental composition. QDs produced from the microfluidic approach were found to agglomerate quickly and had a resulting weak photoluminescent response. This work examined these QDs in two separate solar applications, both for use in light spectrum conversion with solar films and for use in third generation solar cells. For application in light spectrum conversion, the QDs were melt-mixed with ethylene-vinyl-acetate plastic, using a twin-screw extruder and pressed into thin films using a Carver hydraulic press and Universal film maker. QDs were also reviewed for their use in third generation solar cell configurations. Based on the optimal configuration, QD sensitized solar cells were fabricated and tested. Resulting current-voltage (IV) curves and solar cell data showed a direct relation between QD composition and cell efficiency

Yellow Fever

Yellow Fever is a disease that is most common in Africa and South America that causes severe discomfort and has a high mortality rate, of the estimated over 200,000 cases of Yellow Fever, 30,000 cases end in death. Since it is so dangerous, it is important to know how to prevent and treat it if someone ever wanted to travel to either of those places. The disease is relatively easy to avoid, all someone really need to do is avoid mosquitoes either by wearing protective clothing or by avoiding high density mosquito areas. If one were get Yellow Fever, they would surely regret it, since the side effects include head and muscle aches, fever, vomiting blood, yellow skin and eyes, seizures and the possibilities of a coma or even death (University of Maryland Medical Center, 2015)

Establishing the impact of luminous AGN with multi-wavelength observations and simulations

Cosmological simulations fail to reproduce realistic galaxy populations without energy injection from active galactic nuclei (AGN) into the interstellar medium (ISM) and circumgalactic medium (CGM); a process called `AGN feedback'. Consequently, observational work searches for evidence that luminous AGN impact their host galaxies. Here, we review some of this work. Multi-phase AGN outflows are common, some with potential for significant impact. Additionally, multiple feedback channels can be observed simultaneously; e.g., radio jets from `radio quiet' quasars can inject turbulence on ISM scales, and displace CGM-scale molecular gas. However, caution must be taken comparing outflows to simulations (e.g., kinetic coupling efficiencies) to infer feedback potential, due to a lack of comparable predictions. Furthermore, some work claims limited evidence for feedback because AGN live in gas-rich, star-forming galaxies. However, simulations do not predict instantaneous, global impact on molecular gas or star formation. The impact is expected to be cumulative, over multiple episodes.Comment: Accepted for publication in IAU Symposium 378 Conference Proceedings "Black Hole Winds at all Scales

The future design direction of smart clothing development

Literature indicates that Smart Clothing applications, the next generation of clothing and electronic products, have been struggling to enter the mass market because the consumers’ latent needs have not been recognised. Moreover, the design direction of Smart Clothes remains unclear and unfocused. Nevertheless, a clear design direction is necessary for all product development. Therefore, this research aims to identify the design directions of the emerging Smart Clothes industry by conducting a questionnaire survey and focus groups with its major design contributors. The results reveal that the current strategy of embedding a wide range of electronic functions in a garment is not suitable. This is primarily because it does not match the users’ requirements, purchasing criteria and lifestyle. The results highlight the respondents’ preference for personal healthcare and sportswear applications that suit their lifestyle, are aesthetically attractive, and provide a practical function

A mathematical modelling study of an athlete's sprint time when towing a weighted sled

This is the author's accepted manuscript. The final publication is available at Springer via http://dx.doi.org/10.1007/s12283-013-0114-2.This study used a mathematical model to examine the effects of the sled, the running surface, and the athlete on sprint time when towing a weighted sled. Simulations showed that ratio scaling is an appropriate method of normalising the weight of the sled for athletes of different body size. The relationship between sprint time and the weight of the sled was almost linear, as long as the sled was not excessively heavy. The athlete’s sprint time and rate of increase in sprint time were greater on running surfaces with a greater coefficient of friction, and on any given running surface an athlete with a greater power-to-weight ratio had a lower rate of increase in sprint time. The angle of the tow cord did not have a substantial effect on an athlete’s sprint time. This greater understanding should help coaches set the training intensity experienced by an athlete when performing a sled-towing exercise

Realisation of a novel functionally redundant actuation system for a railway track-switch

This paper focuses on modelling, control, realisation and performance analysis of a full-scale demonstrator for a novel railway track switch. For over a century, railway track switches (or points) have been allowing trains to safely change between routes. As they are safety-critical elements of the rail network, when they fail, the signalling system will prevent trains from using that route. This means poor reliability (or lack of availability) leads to significant delays and costs; hence there is huge interest from researchers and engineers in improving the overall reliability of track switches. This paper presents new results, which represent a meaningful first step toward a revolution in the way track switches are actuated. A “REPOINT-Light” railway track switch demonstrator is introduced which uses a new concept of locking to allow redundant actuation with three actuator bearers operating under closed-loop feedback control. The new concept, its control system and its mechanical viability are tested in experiments at the Great Central Railway in the UK. To support the design of the actuators and the control system, a dynamic simulation model is developed by co-simulation involving Simulink and Simpack. The experimental results presented are used to validate the models and the paper discusses how the models themselves are used as the vehicle for the design of feedback controllers. Virtual testing of the controllers in simulation is a vital step prior to the implementation and deployment of the controllers in the demonstrator switch. The major contribution of this work is demonstrating, for the first time at full scale on a real-world track switch, that it is possible to use one-out-of-three actuator redundancy to provide fault-tolerant operation of railway track switch

Realisation of a novel functionally redundant actuation system for a railway track-switch

This paper focuses on modelling, control, realisation and performance analysis of a full-scale demonstrator for a novel railway track switch. For over a century, railway track switches (or points) have been allowing trains to safely change between routes. As they are safety-critical elements of the rail network, when they fail, the signalling system will prevent trains from using that route. This means poor reliability (or lack of availability) leads to significant delays and costs; hence there is huge interest from researchers and engineers in improving the overall reliability of track switches. This paper presents new results, which represent a meaningful first step toward a revolution in the way track switches are actuated. A “REPOINT-Light” railway track switch demonstrator is introduced which uses a new concept of locking to allow redundant actuation with three actuator bearers operating under closed-loop feedback control. The new concept, its control system and its mechanical viability are tested in experiments at the Great Central Railway in the UK. To support the design of the actuators and the control system, a dynamic simulation model is developed by co-simulation involving Simulink and Simpack. The experimental results presented are used to validate the models and the paper discusses how the models themselves are used as the vehicle for the design of feedback controllers. Virtual testing of the controllers in simulation is a vital step prior to the implementation and deployment of the controllers in the demonstrator switch. The major contribution of this work is demonstrating, for the first time at full scale on a real-world track switch, that it is possible to use one-out-of-three actuator redundancy to provide fault-tolerant operation of railway track switch

Supporting patients to self-monitor their oral anticoagulation therapy: recommendations based on a qualitative study of patients' experiences.

BACKGROUND: Clinical trials suggest that oral anticoagulation therapy (OAT) self-monitoring is safe and effective, however little is known about the patient experience of this process. There is a lack of understanding about how best to train and support patients embarking on OAT self-monitoring. AIM: To collect in-depth information about patients' experiences of OAT self-monitoring outside of clinical trial conditions and to produce a set of recommendations on how best to support such patients. DESIGN AND SETTING: Semi-structured qualitative interviews with patients who self-monitor and live in England. METHOD: In total, 26 of the 267 (9.7%) who participated in the Cohort study of Anticoagulation Self-Monitoring (CASM) and were still self-monitoring after 12 months' follow-up were interviewed. Topics discussed included experiences of OAT self-monitoring, healthcare support, training, and decision making. Framework analysis was used. RESULTS: Following initial problems using the monitoring device, interviewees described a mostly positive experience. Although less effort was expended attending monitoring appointments with health professionals, effort was required to conduct self-monitoring tests and to interpret and act on the results. Desire to self-manage was variable, especially when dosing advice systems worked promptly and reliably. Interviewees overcame patchy healthcare system knowledge and support of self-monitoring by educating themselves. Family and friends provided support with learning to use the monitor and managing OAT dosage adjustments. CONCLUSION: Better, more-consistent training and health-service support would have alleviated a number of problems encountered by these patients who were self-monitoring. This training and support will become even more important if self-monitoring becomes more accessible to the general population of people on OAT