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    An investigation of the grindability of two torrefied energy crops

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    The process of torrefaction alters the physical properties of biomass, reducing its fibrous tenacious nature. This could allow increased rates of co-milling and therefore co-firing in coal fired power stations, which in turn would enable a reduction in the amount of coal used and an increase in the use of sustainable fuels, without the need for additional plant. This paper presents an experimental investigation of the pulverisation behaviour of two torrefied energy crops, namely: willow and Miscanthus. A multifactorial method approach was adopted to investigate the three process parameters of temperature, residence time and particle size, producing fuels treated using four different torrefaction conditions. The untreated and torrefied fuels were subjected to standard fuel analysis techniques including ultimate analysis, proximate analysis and calorific value determination. The grindability of these fuels was then determined using a laboratory ball mill and by adapting the Hardgrove Grindability Index (HGI) test for hard coals. After grinding, two sets of results were obtained. Firstly a determination similar to the HGI test was made, measuring the proportion of sample passing through a 75 mu m sieve and plotting this on a calibrated HGI chart determined using four standard reference coals of known HGI values. Secondly the particle size distributions of the entire ground sample were measured and compared with the four standard reference coals. The standard fuel tests revealed that temperature was the most significant parameter in terms of mass loss, changes in elemental composition and energy content increase. The first grindability test results found that the untreated fuels and fuels treated at low temperatures showed very poor grindability behaviour. However, more severe torrefaction conditions caused the fuels to exhibit similar pulverisation properties as coals with low HGI values. Miscanthus was found to have a higher HGI value than willow. On examining the particle size distributions it was found that the particle size distributions of torrefied Miscanthus differed significantly from the untreated biomass and had comparable profiles to those of the standard reference coals with which they had similar HGI values. However, only the torrefied willow produced at the most severe conditions investigated exhibited this behaviour, and the HGI of torrefied willow was not generally a reliable indicator of grindability performance for this energy crop. Overall it was concluded that torrefied biomass can be successfully pulverised and that torrefied Miscanthus was easier to grind than torrefied willow

    Quality of life of patients treated surgically for head and neck cancer

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    The quality of survival of 48 patients treated surgically for head and neck cancer was assessed using a problem-orientated self-administered questionnaire. The questionnaire was based on the European Organization for Research into the Treatment of Cancer (EORTC) core questionnaire to which a specific head and neck module was added. The following domains were studied: pain, fatigue, physical symptoms (gastrointestinal and 'other'), functional activity, psychological symptoms, overall physical condition and overall quality of life. For the analysis, five groups of patients were considered: laryngectomy (n = 15), pharyngolaryngoesophagectomy (n = 5), craniofacial procedure (n = 11), 'other operations' (n = 9) and patients with disease recurrence (n = 8). Each group identified different problem areas. Laryngectomees and 'other operation' patients reported relatively few problems, whereas patients with disease recurrence described difficulties in all of the domains examined. Symptoms of fatigue were common. Information collected in this way may facilitate improved rehabilitation and thus better quality of survival

    Management of treatment resistant schizophrenia

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    Whilst gains have been made in recent years in the pharmacological treatment of schizophrenia, a number of patients still have residual symptoms and disabilities, or simply do not show response to antipsychotic medications. For such 'treatment resistant' patients, there is little by way of randomised controlled data to support any particular type of further intervention, but combinations of agents (combined antipsychotics, augmentation with mood stabilisers, antidepressants, and other agents)can show benefit in certain patients in certain domains of symptomatology and psychosocial functioning. Certain psychological and psychosocial treatment strategies can also be of benefit in this regard. This article selectively reviews the literature treatment resistance in schizophrenia, and emphasises the importance of an holistic approach to individual patients. Keywords: schizophrenia, treatment resistance, antipsychotics, augmentation, psychosocial treatments South African Psychiatry Review Vol. 9(1) 2006: 17-2

    Targeting conservation actions at species threat response thresholds

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    To improve the status of the world’s biodiversity by 2030, conservation actions must not only seek to halt or slow biodiversity loss, they must increase species’ populations. A better mechanistic understanding of biodiversity loss and of species’ sensitivities to certain intensities of threats is needed to target conservation actions effectively. Moving beyond ordinal space-for-time substitution analyses, towards monitoring concurrent changes in threats and species’ populations over time will help achieve this. We propose a framework to quantify species’ response thresholds along gradients of threat intensity, using a combination of threat-sensitive taxa, biogeographic regions, and biomes. This framework will allow efficient targeting of conservation actions, of relevance to global policy-making

    Repeated ischaemic preconditioning: A novel therapeutic intervention and potential underlying mechanisms.

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    Ischaemic preconditioning (IPC) refers to the phenomenon that short periods of cyclical tissue ischaemia confer subsequent protection against ischaemia-induced injury. As a consequence, IPC can ameliorate the myocardial damage following infarction and reduce infarct size. The ability of IPC to confer remote protection makes IPC a potentially feasible cardioprotective strategy. In this review, we discuss the concept that repeatedly exposing tissue to IPC may increase the "dose" of protection, and subsequently lead to enhanced protection against ischaemia-induced myocardial injury. This may be relevant for clinical populations, who demonstrate attenuated efficacy of IPC to prevent or attenuate ischaemic injury (and therefore myocardial infarct size). Furthermore, episodic IPC facilitates repeated exposure to local (e.g. shear stress) and systemic (e.g. hormones, cytokines, blood-borne substances) stimuli, which may induce improvement in vascular function and health. Such adaptation may contribute to prevention of cardio- and cerebro-vascular events. The clinical benefits of repeated IPC may, therefore, result from both the prevention of ischaemic events and attenuation of their consequences. We provide an overview of the literature pertaining to the impact of repeated IPC on cardiovascular function, related to both local and or remote adaptation, as well as potential clinical implications. This article is protected by copyright. All rights reserved
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