Synthesis of Transition Metal - Carbon Nanotube Hybrid Materials

In this thesis research, three novel methodologies have been examined for their use in the synthesis of transition metal - carbon nanotube hybrid materials. These newly synthesized materials were assessed as catalysts in various heterogeneous catalysis reactions, including Fischer Tropsch synthesis, the Sabatier reaction, and the Reverse Water Gas Shift reaction. Specifically, this research was aimed at evaluating the relationship between particle size, support material, and activity of the metal-centerednanotube hybrid catalysts as compared to more traditional heterogeneous catalysts. Efforts were centered on establishing the conditions needed to obtain the optimum metal crystallite size deposited on the nanotube support, as required for achieving the best catalytic activity for a particular reaction scheme. This was done by modifying various synthesis parameters such as the reaction temperature and time, as well as reviewing the metals used for the catalyst deposition. In Fischer Tropsch synthesis, carbon monoxide is hydrogenated over a transition metal catalyst to produce varying length hydrocarbons and olefins. Traditionally, iron, nickel, and cobalt catalysts have been used, and were supported on various oxides and activated carbon. In this thesis research, a series of transition metals, including iron, nickel, cobalt, chromium, and rhodium were deposited on purified single walled carbon nanotubes (SWNTs). SWNTs have recently gained considerable attention do to their unique physical and chemical properties, which can be tailored for the use in numerous applications. In this thesis research, the use of SWNTs as catalyst supports is explored. The large surface area, chemical inertness, mechanical strength, and meso-porous structure, make SWNTs an excellent candidate for a catalyst support material. Catalyst deposition was achieved in this project through an adsorption technique, a direct reduction technique, and through the pre-reduction of the SWNT surface. In typical catalyst synthesis, the metal particles are reduced onto the catalyst support using flowing H2, however, through the use of the proposed adsorption technique, the transition metal is nucleated onto the surface of the SWNTs at the position of a defect site, and is subsequently reduced with the aid of a reducing agent thus causing the growth of the particle. On the other hand, the direct reduction technique involves the modification of the nanotube reduction potential by pre-reducing the SWNTs with alkali metals, such that the metal catalyst particle will be spontaneously reduced and deposited onto the surface of the SWNTs at the position of a defect site. Lastly, the third technique proposed for the synthesis of the hybrid materials involves the pre-reduction of the SWNT surface with a reducing agent, followed by the direct reduction of the metal catalyst particles. This technique yields pristine-like SWNTs, free of most oxidative defects, and causes the transition metals to be reduced and precipitated evenly over the entire surface of the SWNT material. Of these three techniques, the latter was found to produce hybrid materials with well dispersed metal nanoparticles having(TEM). Additionally, these materials were examined for their use as efficient catalysts in the heterogeneous catalysis reactions named previously. Temperature programmed desorption (TPD) data demonstrated the ability of these materials to catalyze the Fischer Tropsch reaction. Additionally, the Rh- SWNT samples have shown evidence that they can be used as catalysts in the Sabatier and Reverse Water Gas Shift reactions when doped with the appropriate reagents as well

Fans, racism and British football in the 21st century: the existence of a colour-blind ideology

This article draws on 2,500 responses from association football (soccer) fans to an anonymous online survey posted from November 2011 to February 2012 examining the extent of racism in British football. The overall findings are that half of all fans are still witnessing or experiencing some form of racism. Despite the creation of anti-racist initiatives, such as Kick It Out, and a reduction in overt chanting, there exists a ‘colour-blind’ ideology amongst the game’s governing bodies and anti-racist organisations as the extent of the problem is largely being ignored. Fans call for a long-term focus on anti-racism based on engagement and education within a greater range of social settings and, short-term, the implementation of more severe punishments by the game’s governing bodies to eliminate racist behaviour amongst fans, players and clubs. For current and ex-players that continue to receive racial abuse through social media sites like Twitter, fans urge them to report it and place these matters in the hands of the police

Football fans’ views of violence in British football: evidence of a sanitized and gentrified culture

This article draws on the responses of 1,500 fans from across the United Kingdom to an online survey posted from August 2013 to November 2013 regarding their experience of football violence. Reflecting the 2013 Home Office report that indicated a continued long-term decline of football fan violence in England and Wales, 89% of fans illustrate a decrease in violent behavior from the 1980s with 56% indicating this is due to better policing, 56% attributing it to improvements in stadia, 50% highlighting the deterrence provided by CCTV, and 49% ascribing it to a civilized supporter base. Overall, fans reflect on a more sanitized and gentrified culture emerging out of measures introduced since the 1990s (including changing police strategies, banning orders, alcohol bans, higher ticket prices, and CCTV)

Football fans’ views of racism in British football

This article analyses 2500 responses from association football (soccer) fans to an anonymous online survey conducted from November 2011 to February 2012 that examined the extent of racism in British football. Eighty-three per cent of the participants stated that racism remains culturally embedded and when exploring the reasons behind its continuation from the 1970s and 1980s, Bourdieu’s concepts of field and habitus proved useful for understanding why some white fans continue to express racist thoughts and behaviours at football. Central to this were explanations concerning class and education and how historical notions of whiteness remain culturally embedded for some supporters

2.2 Validation of the 22-day Honey Bee Larval Toxicity, Repeated (Chronic) Exposure Study Design

Assessing the chronic toxicity of a compound to developing honey bees (Apis mellifera L.) has proven to be a challenge since the mid-2000s. Such data are requested by global regulatory authorities so they can evaluate the risk of compounds to larval honey bees when exposure is likely to occur in the environment. Poor test performance has led to frequent study failures and data uncertainty. Here we highlight a recent effort by the Pollinator Research Task Force (PRTF)1 to validate the use of a method for evaluating the chronic toxicity of a compound (e.g., a pesticide) to an immature honey bee for use in a risk assessment. A ring test protocol was selected and based upon the current OECD guidance document No. 2392 with amendments developed at the University of Florida (Schmehl et al. 2016)3. Fifteen independent laboratories on three continents representing government, academia, and industry followed the same testing protocol to: 1) determine if test performance is robust across different geographic regions and different laboratory personnel and 2) identify limitations associated with the methodology. The control performance criteria for a valid test according to OECD GD 239 is ≥ 85% survival at the end of the larval development and ≥ 70% survival through adult emergence. Thirteen trials (81.3%) satisfied the validity criteria and the test design’s performance was determined adequate for regulatory testing. The toxic reference chemical (dimethoate) had a consistent response with a 22-day EC 50 range of 8-22 μg active substance (a.s.)/g diet. An acetone concentration at the maximum concentration allowed by the OECD GD 239 (2% acetone) was observed to be problematic to test performance. In conclusion, the ring test methods based upon the OECD GD 239 demonstrated that the repeat (chronic) exposure of a compound on developing bees can be successfully conducted. A copy of the full study report4 can be accessed here.Assessing the chronic toxicity of a compound to developing honey bees (Apis mellifera L.) has proven to be a challenge since the mid-2000s. Such data are requested by global regulatory authorities so they can evaluate the risk of compounds to larval honey bees when exposure is likely to occur in the environment. Poor test performance has led to frequent study failures and data uncertainty. Here we highlight a recent effort by the Pollinator Research Task Force (PRTF)1 to validate the use of a method for evaluating the chronic toxicity of a compound (e.g., a pesticide) to an immature honey bee for use in a risk assessment. A ring test protocol was selected and based upon the current OECD guidance document No. 2392 with amendments developed at the University of Florida (Schmehl et al. 2016)3. Fifteen independent laboratories on three continents representing government, academia, and industry followed the same testing protocol to: 1) determine if test performance is robust across different geographic regions and different laboratory personnel and 2) identify limitations associated with the methodology. The control performance criteria for a valid test according to OECD GD 239 is ≥ 85% survival at the end of the larval development and ≥ 70% survival through adult emergence. Thirteen trials (81.3%) satisfied the validity criteria and the test design’s performance was determined adequate for regulatory testing. The toxic reference chemical (dimethoate) had a consistent response with a 22-day EC 50 range of 8-22 μg active substance (a.s.)/g diet. An acetone concentration at the maximum concentration allowed by the OECD GD 239 (2% acetone) was observed to be problematic to test performance. In conclusion, the ring test methods based upon the OECD GD 239 demonstrated that the repeat (chronic) exposure of a compound on developing bees can be successfully conducted. A copy of the full study report4 can be accessed here

An assessment of Pant-y-llyn, Wales' only turlough and comparison to Irish sites

Turloughs are ephemeral karst lakes resulting from high rainfall and, accordingly, high groundwater levels in topographic depressions in karstified limestone terrain. The ephemeral nature of turlough hydrology gives rise to a characteristic ecology as such turloughs have been designated as a Priority Habitat in the EU Habitats Directive (92/43/EEC). While there are recorded turloughs in the Republic of Ireland Pant-y Llyn is Wales’ and mainland Britain’s only recorded turlough; it is a key feature of Cernydd Carmel SSSI and SAC. A collaborative investigation was carried out between Environment Agency Wales and Countryside Council for Wales (soon to be Natural Resources Wales). The main aims of this investigation were to: - Improve the hydrogeological conceptual understanding. - Review the water chemistry of Pant-y-Llyn and the surrounding groundwater. - Compare the hydrology of Pant-y-Llyn with that of recorded Irish turloughs. - Use existing data back model the turlough hydrograph. - Provide evidence to confirm its status for the Habitats Directive. The investigation has shown that Pant y Llyn has both a water quality and hydrological cycle. For the first time comparisons with Irish turloughs allow us to put Pant y Llyn into a wider turlough typology

Three-compartment body composition changes in elite rugby league players during a super league season, measured by dual-energy X-ray absorptiometry.

This study investigated the acute changes in body composition that occur over the course of a competitive season in elite rugby league players. Twenty elite senior players from an English Super League rugby league team underwent a total-body dual-energy X-ray absorptiometry scan at 3 phases of a competitive season: preseason (February), midseason (June), and postseason (September). Body mass (BM), fat mass (FM), lean mass, percentage body fat, and bone mineral content (BMC) were reported at each phase. Between the start and midpoint of the season, BM, lean mass, FM, and body fat percentage showed no significant change (p > 0.05); however, BMC was significantly increased (+0.71%; 30.70 ± 38.00 g; p 0.05); however, significant changes were observed in lean mass (-1.54%; 1.19 ± 1.43 kg), FM (+4.09%; 0.57 ± 1.10 kg), and body fat percentage (+4.98%; 0.78 ± 1.09%; p < 0.05). The significant changes in body composition seen over the latter stages of the competitive season may have implications for performance capabilities at this important stage of competition. An increase in FM and decrease in lean mass may have a negative effect on the power/BM ratio, and therefore may be a cause for concern for playing, coaching, and medical staff. Coaching and strength and conditioning staff should aim to prescribe appropriate training and nutritional practices with the aim of maintaining the players' optimal body composition until the conclusion of the competitive season, in order that performance capabilities are maximized over the entire competition period

Retrospective evaluation of the seasonality of canine tetanus in England (2006-2017):49 dogs

Objective&nbsp;To evaluate the seasonality of canine tetanus in England.Methods&nbsp;Medical records of a single referral hospital in England were reviewed. Dogs diagnosed with localized or generalized tetanus between January 2006 and June 2017 were studied.Results&nbsp;Forty-nine cases were included. The prevalence of tetanus in England was significantly higher in the winter when compared with the summer (P&nbsp;=&nbsp;0.002) and autumn (P&nbsp;=&nbsp;0.024), with the highest number of cases recorded in February.Conclusions&nbsp;The prevalence of canine tetanus in England was significantly higher in winter months, especially in February