The continuous combustion of glycerol in a fluidised bed

It is difficult to burn a liquid fuel inside a fluidised bed. For the first time, liquid glycerol has been burned, when continuously injected into the bottom of an electrically heated bed of alumina particles (sieved to 355 – 425 μm), fluidised by air. The temperature in the bed was held at 700, 800 or 900oC; usually (U/Umf) was 2.5. The bed’s depth was varied, as also were (U/Umf) and the ratio of fuel to air supplied to the bed. Measurements were made of the concentrations of CH4, O2, CO and CO2, and also of the temperature, in the freeboard well above the bed. On entering the bed, the liquid glycerol, rapidly formed bubbles of vapour, which quickly decomposed thermally, yielding mostly CO and H2. These gases then mixed with the other gases in the bed. It appears that the diffusive H2 mainly burns between the fluidised particles. With the bed at 700 – 900oC, no CO was detected far downstream of the bed, provided the equivalence ratio, θ, was below 0.7, i.e. with more than 43 % excess air. Under these fuel-lean conditions, all the carbon in the glycerol was oxidised to CO2. However, in a more fuel-rich situation, with θ > 0.7, CO was detected well above the bed, particularly with a deeper bed, at a lower temperature and operating more fuel-rich. Thus, with the bed at 900oC, CO was mostly oxidised inside the bed, but occasionally some CO burned on top of the bed. When a fuel-rich bed was below 850oC, not all the CO burned in the bed. Achieving complete combustion inside a fluidised bed is partly a problem of mixing the products of glycerol’s thermal decomposition with the fluidising air, which on entry exists mainly in bubbles. Consequently, increasing (U/Umf) promoted both mixing and combustion in a bed. In addition, in-bed combustion requires the bed to be sufficiently deep, hotter than 850oC and θ to be less than a critical value. The effects of other variables are discussed

Prediction of the functional class of metal-binding proteins from sequence derived physicochemical properties by support vector machine approach

Metal-binding proteins play important roles in structural stability, signaling, regulation, transport, immune response, metabolism control, and metal homeostasis. Because of their functional and sequence diversity, it is desirable to explore additional methods for predicting metal-binding proteins irrespective of sequence similarity. This work explores support vector machines (SVM) as such a method. SVM prediction systems were developed by using 53,333 metal-binding and 147,347 non-metal-binding proteins, and evaluated by an independent set of 31,448 metal-binding and 79,051 non-metal-binding proteins. The computed prediction accuracy is 86.3%, 81.6%, 83.5%, 94.0%, 81.2%, 85.4%, 77.6%, 90.4%, 90.9%, 74.9% and 78.1% for calcium-binding, cobalt-binding, copper-binding, iron-binding, magnesium-binding, manganese-binding, nickel-binding, potassium-binding, sodium-binding, zinc-binding, and all metal-binding proteins respectively. The accuracy for the non-member proteins of each class is 88.2%, 99.9%, 98.1%, 91.4%, 87.9%, 94.5%, 99.2%, 99.9%, 99.9%, 98.0%, and 88.0% respectively. Comparable accuracies were obtained by using a different SVM kernel function. Our method predicts 67% of the 87 metal-binding proteins non-homologous to any protein in the Swissprot database and 85.3% of the 333 proteins of known metal-binding domains as metal-binding. These suggest the usefulness of SVM for facilitating the prediction of metal-binding proteins. Our software can be accessed at the SVMProt server

Identification of chromosomes responsible for crown rot resistance in durum wheat

Dissertação de mestrado em Saúde Ocupacional, apresentada á Faculdade de Medicina da Universidade de CoimbraA Segurança, Higiene e Saúde no Trabalho (SHST) tem como objetivo conservar o bem-estar físico, mental e social dos trabalhadores, para isso, é necessário adotar medidas que exigem a interação de várias áreas como a medicina do trabalho, a higiene do trabalho, a engenharia de segurança, a ergonomia, a psicologia, entre outras. Este assunto começou a ser tido em conta, em meados do Séc. XX. Até aí o único aspeto importante relacionado com o trabalho era a produtividade, não havendo preocupação com lesões, doenças nem mesmo se essas situações conduzissem à morte do trabalhador. Tem-se verificado que os riscos psicossociais são riscos emergentes de saúde ocupacional, ou seja, são riscos novos, que estão a aumentar e cujos efeitos sobre a saúde dos trabalhadores estão a agravar-se. As novas formas de contratos de trabalho e insegurança no emprego, a mão-de-obra em envelhecimento, a intensificação do trabalho, as exigências emocionais elevadas no trabalho e a difícil conciliação entre a vida profissional e pessoal são os principais geradores de consequências negativas para os trabalhadores, para as organizações e para a sociedade. Estes riscos requerem grande preocupação por parte das empresas, no entanto devido à delicadeza necessária para abordar esta temática, à escassez dos recursos e à falta de sensibilização, muitas vezes não lhe é dada a devida importância. Os objetivos deste estudo são analisar o nível de exposição da população ativa aos riscos psicossociais, avaliar a capacidade para o trabalho e analisar os efeitos dos riscos psicossociais no trabalho na capacidade para o trabalho. Para atingir os objetivos anteriormente referidos, a metodologia utilizada foram dois questionários, autoadministrados, numa amostra de 140 trabalhadores residentes na localidade de Outil. Com os dados obtidos, foi possível inferir que a população se encontra numa situação de risco intermédio relativamente à exposição aos riscos psicossociais. Este facto não se deve ao sexo do trabalhador nem ao setor em que exerce a sua atividade profissional. Concluiu-se também que a população em estudo apresenta, de um modo geral um bom Índice de Capacidade para o Trabalho (ICT). Este índice vai diminuindo com o avançar Riscos Psicossociais e Capacidade no Trabalho na população de Outil (Cantanhede) XV da idade do trabalhador. O ICT não está correlacionado linearmente com o sexo nem com o setor profissional. Com este estudo verifica-se também que o nível de exposição aos riscos psicossociais se relaciona com a capacidade para o trabalho na medida em que alguns aspetos psicossociais do trabalho potenciam ou inibem a capacidade para o trabalho. Os aspetos que inibem a capacidade para o trabalho são: as exigências quantitativas, os conflitos laborais, a confiança horizontal e vertical, o compromisso face ao local de trabalho, a saúde em geral e os problemas em dormir. Já pelo contrário, o significado do trabalho, a importância que o trabalhador atribui ao trabalho é um fator que potencia a capacidade para o trabalho. A crise económico-financeira atravessada pelo país, e um pouco por toda a Europa, neste momento origina muitas alterações organizacionais e estruturais nas empresas, o que potencia o aparecimento dos riscos psicossociais afetando a saúde física e mental do trabalhador e consequentemente a sua capacidade para o trabalho. O reconhecimento e a gestão dos riscos psicossociais a que estão sujeitos os trabalhadores e a avaliação da sua capacidade para o trabalho tornam mais fácil e eficaz a tomada de decisão e o desenrolar de programas de ação que ajudem as empresas a ultrapassar este momento conturbado a nível socioeconómico e financeiro, mantendo os trabalhadores saudáveis física e mentalmente.The Safety and Health at Work aims to conserve the physical well-being, mental and social workers, for that is necessary to adopt measures that require the interaction of several areas such as occupational medicine, hygiene at work safety engineering, ergonomics, psychology, among others. This issue began to be taken into account in the mid-century. XX, until then the only important aspect related to the work was productivity, with no concern for injury, illness or even if these situations would lead to the death of the workers. It has been found that psychosocial risks are emerging risks to occupational health, it means that they are new risks that are increasing and whose effects on the health of workers are getting worse. The new forms of contracts of work and job insecurity, the hand labor aging, work intensification, high emotional demands at work and the difficult balance between work and personal life are the main triggers of negative consequences for workers, to organizations and to society. These risks require major concern of companies, however because of the sensitivity needed to approach this issue, resources are scarce and the lack of awareness often not been given due importance. The objectives of this study are analyze the level of exposure of the workforce to psychosocial risks, assessing the ability to work and analyze the effects of psychosocial risks at work in the capacity for work. To achieve the above objectives, the methodology used were two questionnaires, self-administered on a sample of 140 workers living in Outil. With the data obtained, it was possible to infer that the population is at an intermediate risk for exposure to psychosocial risks. This is not due to the sex of the worker or the sector where he is pursuing his professional activity. It was also concluded that the study population has, in general a good Work Ability Index (WAI). This ratio decreases with advancing age of the worker. The WAI is not correlated linearly with sex or with the professional sector. The level of exposure to psychosocial risk relates to the ability to work in so far some psychosocial aspects of the work potentiate or inhibit the ability to work. The aspects that inhibit the ability to work are: quantitative requirements, labor disputes, the horizontal and vertical trust, commitment towards the workplace, health in general and trouble sleeping. Already the contrary, the meaning of work, the importance that the worker attaches to the work is a factor that enhances the ability to work. The economic and financial crisis experienced by the country, and almost everywhere in Europe at this time gives many organizational and structural changes in companies, which enhances the appearance of psychosocial risks affecting the physical and mental health of the worker and consequently their ability to the work. Riscos Psicossociais e Capacidade no Trabalho na população de Outil (Cantanhede) XVII The recognition and management of psychosocial risks to which they are subject workers and the evaluation of their ability to make work easier and more effective decision-making and the development of programs which help companies overcome this troubled time the level socio-economic and financial, keeping the physical and mentally healthy worker

Are tourists with higher expectation more sensitive to service performance? Evidence from urban tourism

This study aims to revisit the classic topic of tourist satisfaction formation in the context of urban tourism, and contribute to the dialogue by verifying an expectation-as-moderator paradigm. A model depicting the relationship between expectation, service performance, perceived value, and tourist satisfaction was constructed and tested based on three-year survey data collected from two major sectors of tourism industry in Hong Kong (accommodation and attraction), using Moderated Structural Equation Model. The results reveal that the moderation effect of tourist expectation exists in accommodation sector, but does not exist in attraction sector. The conclusion suggests that tourists with higher expectation towards accommodation service tend to be more sensitive to service performance. Theoretical and practical implications are discussed

High-Pressure Phase Stability and Superconductivity of Pnictogen Hydrides and Chemical Trends for Compressed Hydrides

Binary hydrides formed by the pnictogens of phosphorus, arsenic and antimony are studied at high pressures using first principles methods. Stable structures are predicted and their electronic, vibrational and superconducting properties are investigated. We predict that SbH$_{4}$ and AsH$_{8}$ will be high-temperature superconductors at megabar pressures, with critical temperatures in excess of 100 K. The highly symmetric hexagonal SbH$_{4}$ phase is predicted to be stabilized above about 150 GPa, which is readily achievable in diamond anvil cell experiments. We find that all phosphorus hydrides are metastable with respect to decomposition into the elements within the pressure range studied. Trends based on our results and literature data reveal a connection between the high-pressure behaviors and ambient-pressure chemical quantities which provides insight into understanding which elements may form hydrogen-rich high-temperature superconducting phases at high pressures.The authors thank Eva Zurek for sharing structure data for iodine hydride. The work at Jilin Univ. is supported by the funding of National Natural Science Foundation of China under Grant Nos. 11274136 and 11534003, 2012 Changjiang Scholar of Ministry of Education and the Postdoctoral Science Foundation of China under grant 2013M541283. L.Z. acknowledges funding support from the Recruitment Program of Global Youth Experts in China. Part of calculations was performed in the high performance computing center of Jilin Univ. R.J.N. acknowledges financial support from the Engineering and Physical Sciences Research Council (EPSRC) of the UK [EP/J017639/1]. R.J.N. and C.J.P. acknowledge use of the Archer facility of the U.K.’s national high-performance computing service (for which access was obtained via the UKCP consortium [EP/K013564/1]).This is the final version of the article. It first appeared from ACS via https://doi.org/10.1021/acs.chemmater.5b0463

Power-free water pump based on a superhydrophobic surface: generation of a mushroom-like jet and anti-gravity long-distance transport

Spontaneous anti-gravitational transportation of liquids across long distances has been widely discovered in nature, such as water transportation from the root to the crown of a tree. However, artificial liquid delivery remains a challenge. In this work, a new power-free pump composed of a superhydrophobic plate with a pore mounted on a leak-proof cylindrical container filled with water is presented for sustained anti-gravity and long distance transport. Water droplets can be spontaneously captured through the pore by the lower water column, forming a mushroom-like jet due to the energy transition from surface energy to kinetic energy. The spontaneously increased inside pressure in the container will push the water out, through another thin tube, realizing the energy transition from surface energy to gravitational potential energy. The dynamic driving and moving model of the pivotal mushroom-like jet were analyzed. The maximum transport height and transport abilities of the water pump were also discussed. The results show that Laplace pressure is the main driving pressure of the mushroom-like jet and that the developed power-free pump can effectively transport water to over 100 mm in height with an average transport speed of 4500 μL h−1, showing potential for application in microfluidic systems and medical devices where micropumps are needed

The roles of apex dipoles and field penetration in the physics of charged, field emitting, single-walled carbon nanotubes

A 1 μm long, field emitting, (5, 5) single-walled carbon nanotube (SWCNT) closed with a fullerene cap, and a similar open nanotube with hydrogen-atom termination, have been simulated using the modified neglect of diatomic overlap quantum-mechanical method. Both contain about 80 000 atoms. It is found that field penetration and band bending, and various forms of chemically and electrically induced apex dipole play roles. Field penetration may help explain electroluminescence associated with field emitting CNTs. Charge-density oscillations, induced by the hydrogen adsorption, are also found. Many of the effects can be related to known effects that occur with metallic or semiconductor field emitters; this helps both to explain the effects and to unify our knowledge about FE emitters. However, it is currently unclear how best to treat correlation-and-exchange effects when defining the CNT emission barrier. A new form of definition for the field enhancement factor (FEF) is used. Predicted FEF values for these SWCNTs are significantly less than values predicted by simple classical formulae. The FEF for the closed SWCNT decreases with applied field; the FEF for the H-terminated open SWCNT is less than the FEF for the closed SWCNT but increases with applied field. Physical explanations for this behavior are proposed but the concept of FEF is clearly problematical for CNTs. Curved Fowler-Nordheim plots are predicted. Overall, the predicted field emission performance of the H-terminated open SWCNT is slightly better than that of the closed SWCNT, essentially because a C-H dipole is formed that reduces the height of the tunneling barrier. In general, the physics of a charged SWCNT seems much more complex than hitherto realized. © 2008 American Institute of Physics.published_or_final_versio

Respiratory modulation of oscillometric cuff pressure pulses and Korotkoff sounds during clinical blood pressure measurement in healthy adults

BACKGROUND: Accurate blood pressure (BP) measurement depends on the reliability of oscillometric cuff pressure pulses (OscP) and Korotkoff sounds (KorS) for automated oscillometric and manual techniques. It has been widely accepted that respiration is one of the main factors affecting BP measurement. However, little is known about how respiration affects the signals from which BP measurement is obtained. The aim was to quantify the modulation effect of respiration on oscillometric pulses and KorS during clinical BP measurement. METHODS: Systolic and diastolic BPs were measured manually from 40 healthy subjects (from 23 to 65 years old) under normal and regular deep breathing. The following signals were digitally recorded during linear cuff deflation: chest motion from a magnetometer to obtain reference respiration, cuff pressure from an electronic pressure sensor to derive OscP, and KorS from a digital stethoscope. The effects of respiration on both OscP and KorS were determined from changes in their amplitude associated with respiration between systole and diastole. These changes were normalized to the mean signal amplitude of OscP and KorS to derive the respiratory modulation depth. Reference respiration frequency, and the frequencies derived from the amplitude modulation of OscP and KorS were also calculated and compared. RESULTS: Respiratory modulation depth was 14 and 40 % for OscP and KorS respectively under normal breathing condition, with significant increases (both p  0.05) during deep breathing, and for the oscillometric signal during normal breathing (p > 0.05). CONCLUSIONS: Our study confirmed and quantified the respiratory modulation effect on the oscillometric pulses and KorS during clinical BP measurement, with increased modulation depth under regular deeper breathing

High capacity silicon anodes enabled by MXene viscous aqueous ink

The ever-increasing demands for advanced lithium-ion batteries have greatly stimulated the quest for robust electrodes with a high areal capacity. Producing thick electrodes from a high-performance active material would maximize this parameter. However, above a critical thickness, solution-processed films typically encounter electrical/mechanical problems, limiting the achievable areal capacity and rate performance as a result. Herein, we show that two-dimensional titanium carbide or carbonitride nanosheets, known as MXenes, can be used as a conductive binder for silicon electrodes produced by a simple and scalable slurry-casting technique without the need of any other additives. The nanosheets form a continuous metallic network, enable fast charge transport and provide good mechanical reinforcement for the thick electrode (up to 450 µm). Consequently, very high areal capacity anodes (up to 23.3 mAh cm−2) have been demonstrated