Redox reforming based, integrated solar-natural gas plants: Reforming and thermodynamic cycle efficiency

As demand for energy continues to rise, the concern over the increase in emissions grows, prompting much interest in using renewable energy resources such as solar energy. However, there are numerous issues with using solar energy including intermittency and the need for storage. A potential solution is the concept of hybrid solar-fossil fuel power generation. Previous work has shown that utilizing solar reforming in conventional power cycles has higher performance compared to other integration methods. Most previous studies have focused on steam or dry reforming and on specific component analysis rather than a systems level analysis. In this article, a system analysis of a hybrid cycle utilizing redox reforming is presented. Important cycle design and operation parameters such as the oxidation temperature and reformer operating pressure are identified and their effect on both the reformer and cycle performance is discussed. Simulation results show that increasing oxidation temperature can improve reformer and cycle efficiency. Also shown is that increasing the amount of reforming water leads to a higher reformer efficiency, but can be detrimental to cycle efficiency depending on how the reforming water is utilized.Center for Clean Water and Clean Energy at MIT and KFUPM (Project Number R12-CE-10)King Abdullah University of Science and Technology (KAUST

Ideas to Design an in situ Diamond Drilling Core Splitter within Soft Rocks

Diamond drilled cylindrical rock (core) from the earth is usually extracted using a drill rig. This is followed by splitting, at the surface with the aid of diamond impregnated saw blade, for good visual examination before sampling for analysis. The challenges in core splitting are imperfect division, time consuming, labour intensive and dust generation. This paper studied the wireline system of core barrel assembly and the device used in splitting of core (core splitting machine) at the surface, to provide ideas which would help design a mechanism that would take care of the splitting of the core in situ (i.e. at depth during the drilling process). Modifications of the core barrel assembly of the wireline system are such that the outer tube assembly is designed to have two ball bearings moulded with it. The back end assembly is designed to have a latching system which could operate independently. Also a static diamond cutting blade is inserted in the core lifter to split soft rocks or saprolite (with hardness of less than 5 on the Mohr’s scale) when a resultant feed force is applied. The stop ring in the inner tube should effectively grab the split core to prevent it from dropping and also protect the split core from washing away. Drilling at short intervals with controlled drill fluid usage is recommended in saprolite zone. Following the ideas provided, an in situ core splitter could be designed to eliminate hazards associated with conventional core splitting on the surface, save time and reduce dust generation.Keywords: Design, In situ, Diamond drilling, Core splitter, Wireline syste

Dry redox reforming hybrid power cycle: Performance analysis and comparison to steam redox reforming

There has been much interest in the use of renewable resources for power generation as the world's energy demand and the concern over the rise in emissions increases. In the near term, however, renewable sources such as solar energy are expected to provide a small fraction of the world's energy demand due to intermittancy and storage problems. A potential solution is the use of hybrid solar-fossil fuel power generation. Previous work has shown the potential of steam redox reforming for hybridization. However, this type of reforming requires some water consumption (which may be infeasible in certain locations) as not all the water can be recovered through recycling. An alternative is to utilize dry (or CO2) redox reforming. In this paper, a system analysis for a CO2 redox reforming hybrid cycle and comparison of cycle and reformer performance between a CO2 redox reformer and steam redox reformer hybrid cycle are presented. The effect of important operating parameters such as pressure, amount of reforming CO2, and the oxidation temperature on the reformer and cycle performance are discussed. Simulation results show that increasing the oxidation temperature or the amount of reforming CO2 leads to higher reformer and cycle efficiencies. In addition, the comparison between the CO2 and steam redox reformer hybrid cycles shows that the CO2 cycle has the potential to have better overall performance.King Fahd University of Petroleum and Minerals (KFUPM (Project No. R12-CE-10)

Understanding independent living customers at Trafford Housing Trust : an evaluation

This report provides the findings of the evaluation of TrustCare, an independent arm of Trafford Housing Trust which offers independent living services. The report offers the findings of the evaluation reporting on each stage of the process and drawing on both quantitative (descriptive statistics) and qualitative data (semi-structured interviews) collected during July and August 2017

A review of solar methane reforming systems

Because of the increasing demand for energy and the associated rise in greenhouse gas emissions, there is much interest in the use of renewable sources such as solar energy in electricity and fuels generation. One problem with solar energy, however, is that it is difficult to economically convert the radiation into usable energy at the desired locations and times, both daily and seasonally. One method to overcome this space-time intermittency is through the production of chemical fuels. In particular, solar reforming is a promising method for producing chemical fuels by reforming and/or water/carbon dioxide splitting. In this paper, a review of solar reforming systems is presented, as well as a comparison between these systems and a discussion on areas for potential innovation including chemical looping and membrane reactors. Moreover, a brief overview of catalysis in the context of reforming is presented

Prevalence of cardiovascular-related comorbidity in ankylosing spondylitis, psoriatic arthritis and psoriasis in primary care: a matched retrospective cohort study

The aim of this study is to compare the prevalence of cardiovascular (CVD)-related comorbidities in patients with ankylosing spondylitis (AS), psoriatic arthritis (PsA) or psoriasis (Ps) in UK primary care against matched cohorts. Matched retrospective cohort study used a primary care consultation database. Three cohorts were constructed using all patients with a Read code diagnosis of AS, PsA or Ps between 1999 and 2009; each cohort was then compared in a 1:4 ratio to a matched cohort. The prevalence of CVD-related comorbidities (hypertension, ischaemic heart disease, hyperlipidaemia and diabetes mellitus) were identified by the first consultation of a comorbid Read code, in those with an inflammatory condition of interest. The prevalence of CVD-related comorbidities was compared between each inflammatory cohort and their matched cohort using Fisher’s exact test. Ninety-four AS, 106 PsA and 290 Ps patients were identified. Compared with matched cohorts, the most prevalent CVD-related comorbidity in patients with AS was hypertension (35 (37.2 %) vs. 96 matched (25.5 %), p = 0.03); this was also the case for PsA (41 (38.7 %) vs. 114 matched (26.9 %), p = 0.02). No differences were seen in the prevalence of other CVD-related comorbidities in those with AS, PsA or Ps compared to their matched cohorts. Our findings provide UK comparisons of CVD-related comorbidities in patients with AS, PsA and Ps alone; specifically, demonstrating increased prevalence of hypertension in AS and PsA cohorts compared to their matched cohorts. This further supports the argument for more evidence in the need for screening and intervention around CVD comorbidities in inflammatory conditions

Syntheses of Combretastatin A‐4 and Related Stilbenes by Using Aqueous Conditions

Combretastatin A-4 (CA4) is a potent anti-mitotic and vascular disrupting agent. Organic chemists have been working to optimize the synthesis of CA4 for the past 3 decades, with methods requiring hazardous solvents and harsh reaction conditions. Here, we report the synthesis of CA4 and a variety of stilbenes in an aqueous Wittig system. Potassium carbonate or lithium hydroxide were used as base in this Wittig reaction to give excellent yields of mixtures of E- and Z-stilbenes. The synthesis of CA4 was achieved using tetrahydropyran (THP) or silyl protected phenolic aldehydes. The THP groups were removed using dilute acid whilst the silyl groups fortuitously fell off during work up

Relationship between age, radiographic normal heart size and cardio-thoracic ratio in a Nigerian population

Background: Cardio-vascular disease (CVD) is now on the increase. The precise diagnosis of CVD is of immense clinical importance to the cardiac surgeons, pathologist and also for cardiologists. However, information on normal values for various cardio-vascular structures in Nigeria, a country with the highest population of blacks in the world is sparse. In this regard the age-related radiographic sizes of a Nigerian cohort of patients with non-cardiogenic complaints or consultations were therefore assessed.Objectives: To evaluate the limits of normal cardiac size in our environment , determine if there was a relationship between the age and size of the heart and to evaluate the relationship between sex and cardiac size and cardio-thoracic ratio.Design: A cross-sectional study.Setting: The Radiology department of University of Ilorin Teaching Hospital, Ilorin, North Central Nigeria between January to June 2012.Subjects: One Hundred patients were consecutively recruited and their chest radiographs examined after fulfilling the inclusion criteria.Results: Males accounted for 55% of the study population. The age range was 1 month to 73 years, (Mean = 29.3, SD =2.41668). The mean cardiac size was 11.7cm. The average cardiac size for adult males and females, were 11.6cm and 11.5cm respectively while that of thoracic size was 29.0cm and 26.8cm respectively. Correlation between age and cardiac size was 0.66; age and thoracic size was 0.64 and between cardiac size and thoracic size was 0.89. The paired sample t-test for age and cardiac size was less than 0.05 (p value <0.05).Conclusion: knowing the average values of cardiac size for adult males and females (11.6cm and 11.5cm) and thoracic size (29.0cm and 26.8cm) respectively from this study presents a base line for early detection of variation from normal cardiac measurements in this environment

Assessing the impacts of various street-level characteristics on the burden of urban burglary in Kaduna, Nigeria

Evidence suggests that crimes committed in urban environments are geographically concentrated across a range of scales, and that the variation in rates of crime within an urban space is significantly dependent on the physical environment as well as the situation in which the crime takes place. However, these assertions are typically drawn from environmental criminological studies that have focussed on Euro-American cities and western intellectual perspectives. We seek to move beyond these by focussing on a second-tier city in sub-Saharan Africa (Kaduna, Nigeria), a context for which very little literature exists. This paper therefore examines the association between a range of street characteristics and the risk of residential burglary in Kaduna for the first time. It describes a methodology for conducting a household crime victimisation survey in Nigeria, and then aggregating the information to a street-level to perform a population-based ecological study. It integrates street network analysis and statistical modelling techniques in order to provide novel estimates for factors that may increase the risk of burglary such as street accessibility metrics (e.g. connectivity, betweenness and closeness centrality), segment length, socioeconomic status and business activities. Finally, the article provides a discussion on the plausibility and implication of findings within the sub-Saharan African context