Aerodynamic study of single stage multi-blade drag-based vertical axis wind turbines

Harnessing wind energy in built-up areas to generate power by a wind turbine for domestic application still remains a challenge despite considerable research has been undertaken in this area. The complex wind conditions in built-up areas, manufacturing complexity and the cost make most wind turbines unattractive for domestic application. For the use in built-up areas, vertical axis wind turbines are preferable due to their omni-directional characteristics, aesthetics, low noise and safety. Despite having these advantages, most vertical axis wind turbines available in the market are not producing appreciable power. An innovative and low cost vertical axis wind turbine with appreciable power generation capacity can provide a competitive edge to its peer. The primary objective of this study is to develop a micro vertical axis wind turbine suitable for built-up areas. To achieve this objective, a series of vertical axis wind turbines with multiple blades have been designed, manufactured and studied experimentally. A total of thirteen single stage multi-blade drag-based vertical axis wind turbines (6 with 300 mm diameter, four with 200 diameter and three with 600 mm diameter) with various blade configurations were investigated using RMIT Industrial Wind Tunnel. The blade shape of each turbine is semi-circular with zero twisting. Each turbine’s rotational speed (RPM), torque (T) and power (P) were determined under the wind speed ranging from 4.5 m/s (16 km/h) to 8.5 m/s (31 km/h). Smoke and wool tuff flow visualisations techniques were used to understand airflow characteristics in and around each prototype turbine. For each prototype wind turbine, a graphical relation between power and rotational speed, power coefficient and tip speed ratio, and maximum torque and number of blades were constructed. The effect of wind turbulence on power output has also been studied. At all speed range studied, the 300 mm diameter turbine with 32 blades produced highest torque and power amongst all 300 mm diameter configurations. Similarly, the 200 mm diameter turbine with 19 blades generated highest torque and power amongst 200 mm diameter turbines. An empirical relationship has been established to determine the optimal blade number for a constant diameter multi-blade single stage drag-base vertical axis wind turbine. The experimental data obtained for two different diameter prototype turbines have confirmed the validity of the developed empirical relationship. Power is highly dependent on blade number and blade spacing. With the increase of blade number, the power increases till it reaches an optimal blade number thereafter it starts to decrease. The optimal blade spacing was determined to be in between 5.5 mm and 6.5 mm for all turbines studied. A flow enhancing device (cowling) was designed and employed to explore its effectiveness on turbine rotational speed (RPM) and torque. The flow enhancing device had shown a positive impact on the turbine RPM however, the overall torque and power was found to be lower compared to turbines without its employment. Wind turbulence intensity has significant impact on power output. The power decreases with an increase of turbulence. However, the airflow rate or volume flow rate has much higher impact on the power output. The power can be increased by approximately two times when the blade diameter is scaled up. Doubling the blade diameter increases the amount of wind energy the turbine blades are able to extract. However, it is found that the power output does not increase proportionally as the optimal power output depends on a) blade number, b) blade spacing, c) blade angle, d) turbulence intensity, and e) airflow rate. In an open environment, small scale vertical axis wind turbine blades can experience wind with varied gustiness due to variety of structures. This can have effect on aerodynamic parameters optimised in controlled wind conditions in the wind tunnel. Therefore, it would be useful to undertake a field study to determine the wind gustiness effect on power output

Review and selection of recycling technology for lithium-ion batteries made for EV application - A life cycle perspective

The lithium-ion battery is the source of renewable energy and the battery-operated vehicles are gradually replacing fossil fuel-based automobiles. Though Electric Vehicles (EVs) do not produce emissions through tailpipes, yet the issues pertaining to recycling of the lithium-ion batteries employed in EVs lead to environmental burdens. The EVs sale in global market exceeds a million per year. It is estimated that there will be a huge amount of unprocessed waste of lithium-ion battery packs when these vehicles retire after the service life. The re-use of batteries can reduce the waste generation, however the cumulative burden of the battery wastes will be substantial considering the increasing trend of the electric-vehicle market. There are various methods employed for recycling of lithium-ion batteries. The existing literature reports that their environmental impact is significant. The challenge is to choose a method which causes minimal disruptions to the environment in terms of cost, pollution and energy consumption, which can be effectively addressed by a life cycle analysis based selection method. In this paper, a review is conducted on the current recycling technologies and WPM (Weighted Product Method) based Multi-Criteria Approach is employed to optimally choose the best recycling process for lithium-ion batteries from life cycle perspective

Relational Solidarity and Conflicting Ethics in Dementia Care in Urban India.

OBJECTIVES: Using the concept of relational solidarity, we examine how autonomy, equality, dignity, and personhood are practiced in the care of people living with dementia at home in urban India. METHODS: Video interviews with 19 family carers and 25 health providers conducted in English, Hindi, and Kannada in Bengaluru between March and July 2022. Data were translated into English and thematically analyzed. RESULTS: Family carers and providers unanimously agreed that people with dementia should be respected and cared for. Concurrently, they perceived people with dementia as being "like a kid" and used the analogy of a parent-child relationship to understand their care responsibilities. This analogy informed how ethical principles such as personhood and equality were reframed in the relationships between family carers and people with dementia, as well as how carers and providers maintained the safety but undermined the autonomy of people with dementia through restricting their movements inside and outside the home. DISCUSSION: There can be relational solidarity in dementia care at home in urban India but also contradictions in the interpretations and applications of the ethical principles of autonomy, equality, dignity, and personhood. As such, a more organic, grassroots model of ethical practice is needed to frame care and provide material support to families in India

Persistent Organic Chemicals in the Pacific Basin Countries: An Overview

The Pacific Basin is a unique geographical region representing tropical, temperate and polar zones. This region is home to 2/3 of world’s population and consists of rapidly growing economies (countries) and highly developed countries. The Pacific Basin countries have had a history of use of persistent organic chemicals (POCs) at varying proportions during the last five decades. Due to diverse climatic and socio-economic conditions, the environment and biota in different countries in this basin have varying degrees of environmental contamination and effects on wildlife and humans. In this chapter, the historical background of POCs including, discovery, production, use, regulations/restrictions imposed, current status and possible future trends are reviewed especially focusing on the countries in the Pacific Rim

The microaerophilic microbiota of de-novo paediatric inflammatory bowel disease: the BISCUIT study

<p>Introduction: Children presenting for the first time with inflammatory bowel disease (IBD) offer a unique opportunity to study aetiological agents before the confounders of treatment. Microaerophilic bacteria can exploit the ecological niche of the intestinal epithelium; Helicobacter and Campylobacter are previously implicated in IBD pathogenesis. We set out to study these and other microaerophilic bacteria in de-novo paediatric IBD.</p> <p>Patients and Methods: 100 children undergoing colonoscopy were recruited including 44 treatment naïve de-novo IBD patients and 42 with normal colons. Colonic biopsies were subjected to microaerophilic culture with Gram-negative isolates then identified by sequencing. Biopsies were also PCR screened for the specific microaerophilic bacterial groups: Helicobacteraceae, Campylobacteraceae and Sutterella wadsworthensis.</p> <p>Results: 129 Gram-negative microaerophilic bacterial isolates were identified from 10 genera. The most frequently cultured was S. wadsworthensis (32 distinct isolates). Unusual Campylobacter were isolated from 8 subjects (including 3 C. concisus, 1 C. curvus, 1 C. lari, 1 C. rectus, 3 C. showae). No Helicobacter were cultured. When comparing IBD vs. normal colon control by PCR the prevalence figures were not significantly different (Helicobacter 11% vs. 12%, p = 1.00; Campylobacter 75% vs. 76%, p = 1.00; S. wadsworthensis 82% vs. 71%, p = 0.312).</p> <p>Conclusions: This study offers a comprehensive overview of the microaerophilic microbiota of the paediatric colon including at IBD onset. Campylobacter appear to be surprisingly common, are not more strongly associated with IBD and can be isolated from around 8% of paediatric colonic biopsies. S. wadsworthensis appears to be a common commensal. Helicobacter species are relatively rare in the paediatric colon.</p&gt

Real-Life Anti-Tumour Necrosis Factor Experience in > 500 Paediatric United Kingdom Inflammatory Bowel Disease Patients.

OBJECTIVES: To measure the effectiveness, safety and use of anti-Tumour necrosis Factor (TNF) therapy in paediatric inflammatory bowel disease (PIBD) in the United Kingdom (UK). METHODS: Prospective UK audit of patients newly starting anti-TNF therapy. Disease severity was assessed using Physician Global Assessment (PGA) +/or the Paediatric Crohn's Disease Activity Index (PCDAI). RESULTS: 37 centres participated (23 of 25 specialist PIBD sites). 524 patients were included; 429 Crohn's disease (CD), 76 ulcerative colitis (UC), 19 IBD unclassified (IBDU). 87% (488/562) anti-TNF was infliximab; commonest indication was active luminal CD 77% (330/429) or chronic refractory UC/IBDU 56% (53/95); 79% (445/562) had concomitant co-immunosuppression. In CD (267/429 male), median time from diagnosis to treatment was 1.42 years (IQR 0.63-2.97). Disease (at initiation) was moderate or severe in 91% (156/171) by PGA compared to 41% (88/217) by PCDAI; Kappa (Κ) 0.28 = only 'fair agreement' (p < 0.001).Where documented, 77% (53/69) of CD patients responded to induction; and 65% (46/71) entered remission. 2287 infusions and 301.96 years of patient follow-up (n = 385) are represented; adverse events affected 3% (49/1587) infliximab and 2% (2/98) adalimumab infusions (no deaths or malignancies). Perianal abscess drainage was less common after anti-TNF initiation (CD): 26% (27/102) before, 7% (3/42) after (p = 0.01); however pre and post anti-TNF data collection was not over equal time periods. CONCLUSION: Anti-TNFs are effective treatments, usually given with thiopurine co-immunosuppression. This study highlights deficiencies in formal documentation of effect and disparity between disease severity scoring tools which need to be addressed to improve ongoing patient care

Solving the multi-period water distribution network design problem with a hybrid simulated anealling

This work presents an optimization technique based on Simulated Annealing (SA) to solve the Water Distribution Network Design problem, considering multi-period restrictions with time varying demand patterns. The design optimization of this kind of networks is an important issue in modern cities, since a safe, adequate, and accessible supply of potable water is one of the basic necessities of any human being. Given the complexity of this problem, the SA is improved with a local search procedure, yielding a hybrid SA, in order to obtain good quality networks designs. Additionally, four variants of this algorithm based on different cooling schemes are introduced and analyzed. A broad experimentation using different benchmark networks is carried out to test our proposals. Moreover, a comparison with an approach from the literature reveals the goodness to solve this network design problem.Fil: Bermudez, Carlos Alberto. Universidad Nacional de la Pampa. Facultad de Ingeniería; ArgentinaFil: Salto, Carolina. Universidad Nacional de la Pampa. Facultad de Ingeniería; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Confluencia; ArgentinaFil: Minetti, Gabriela Fabiana. Universidad Nacional de la Pampa. Facultad de Ingeniería; Argentin