578 research outputs found

    Changing the physical and chemical properties of titanium oxynitrides TiN1-x Ox by changing the composition

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    The stability and structural properties of titanium oxynitrides, TiN1-x Ox, of different compositions are theoretically analyzed by means of first-principles periodic density-functional calculations. We show that at x=0.55-0.6 there is a change in the preferred structure from that of NaCl type to the α-TiO arrangement. For the NaCl-type structure the cell volume increases with x while it decreases with x for the α-TiO structure. The bulk moduli are always much larger for NaCl-type structures than for α-TiO and they decrease as the amount of O increases, moving from 280 GPa for TiN to 226 GPa for TiO (NaCl-type structure) or 197 GPa for α-TiO. Changes in the electronic structure with the composition are also considered. In general we found that in the two types of structure (NaCl and α-TiO), both the band gap and the ionic character increase with the O concentration.Ministerio de Ciencia e Innovación MAT2008-04918Consolider Ingenio CSD2008–0002

    Can Organic P Inputs Alleviate P Limitation Effects on Nutrient Uptake and Biological N2‑Fixing Capacity of Hairy Vetch (Vicia villosa)?

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    Phosphorus (P) is a limiting nutrient in many agroecosystems and, apart from affecting plant growth, can also limit biological N2 fixation (BNF) by leguminous plants. Thus, increasing P supply can have a positive effect on BNF particularly in P-deficient soils. Here, we provide new insights into the response of hairy vetch (Vicia villosa), widely adopted as a legume cover crop, to P limitations, by comparing the effects of inorganic (Pi) and organic (Po) P supply on plant growth and BNF capacity. This was achieved by means of a greenhouse experiment in which rhizobia-inoculated hairy vetch was grown in a P-limited agricultural soil and changes in plant growth, nitrogen (N) and P uptake, BNF capacity, and soil phosphatases activities were evaluated as a function of Pi and Po inputs, in the form of orthophosphate or phytic acid, respectively. When compared to P-deficient conditions where BNF was primarily limited by plant growth rather than directly due to the high P costs of symbiotic N fixation, Pi addition substantially enhanced plant growth (threefold), nodule formation (16-fold), P acquisition (sixfold), and BNF efficiency (sevenfold). In contrast, even with the addition of the highest dose of Po, the increase in plant growth, nodule formation, P acquisition, and BNF capacity (1.7, 3.5, 2.4 and 2.1-fold, respectively) was much less expressed, indicating that hairy vetch could only minimally access Po sources over the growth period in order to alleviate the P limitation effect on N2 fixation in under P-deficient conditions. These findings suggest that hairy vetch will not be able to provide sufficient BNF for improving soil N inputs in low-fertility cropping systems that rely on organic inputs.Universita degli Studi di Torino within the CRUI-CARE AgreementCassa di Risparmio di Torin

    Clonación y análisis de la estructura primaria de quitina sintasas de entamoeba histolytica: perfil de expresión durante el enquistamiento

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    Entamoeba histolytica, parásito responsable de la amibiasis, presenta dos etapas en su ciclo de vida: trofozoíto y quiste. Los quistes (forma infectiva) poseen una pared compuesta principalmente por quitina, polímero de ß-(1→4)-N-acetil-Dglucosamina cuya síntesis es catalizada por quitina sintasas (CHS). Las CHS se han descrito en hongos, insectos y nemátodos, pero no en protozoarios como Entamoeba. Se clonaron y secuenciaron dos genes CHS de E. histolytica. Se determinó que ambas EhCHS contienen segmentos transmembranales en sus extremos, y que la mayor similitud está restringida a la «región catalítica»; los aminoácidos importantes para la actividad de CHS están completamente conservados en ambas EhCH

    Conventional and Molecular Diagnosis of Drug-Sensitive and Drug-Resistant Pulmonary Tuberculosis

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    Tuberculosis is a transmissible disease, which is primarily caused by the bacteria Mycobacterium tuberculosis and by other Mycobacterium species, forming the Mycobacterium tuberculosis complex. Until the end of the 20th Century, most cases of pulmonary tuberculosis were considered curable. Nevertheless, the rising of tuberculosis resistant to first- and second-line anti-tuberculous drugs is threatening the world’s tuberculosis control programs. Due to this fact, the World Health Organization and other public health institutions recommended applying the conventional methods, affordable by low-incoming countries, to diagnose tuberculosis and to develop faster and more sensitive and specific methods to identify M. tuberculosis and determine their condition of anti-tuberculous drug resistance or drug sensitivity. In this chapter, we mention the most used conventional and molecular methods designed to identify M. tuberculosis and to determine their drug sensitivity or drug resistance. We also briefly describe the fundamentals of methods and its advantages and limitations

    Ultrasonic techniques to obtain dental pulp from impacted third molars

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    In the dental clinic impacted teeth are frequent findings, especially upper and lower third molars, leading to their exodontia. Among surgical techniques piezosurgery is advantageous for delicate structures in the oral cavity. Extracted teeth, usually di

    Toward Green Chemical Engineering

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    The chemicals industry and other related industries supply us with a huge variety of essential products to everyday living. However, these industries have the potential to seriously damage our environment. In the last decade, the scientific community has witnessed a growing interest in environmental issues and the value of environmentally friendly energy generation and chemical processes. The combination of chemical engineering tools with the findings of green chemists, biologists, and environmental scientists has allowed the design of new processes for the manufacture of chemicals, fuels, and products with a much reduced environmental footprint. Furthermore, the developed environmentally benign alternative technologies have been proven to be economically superior and function as well as or better than more toxic traditional optionsMinisterio de Ciencia e Innovación

    Numerical Analysis of Unsteady Hybrid Nanofluid Flow Comprising CNTs-Ferrousoxide/Water with Variable Magnetic Field

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    The introduction of hybrid nanofluids is an important concept in various engineering and industrial applications. It is used prominently in various engineering applications, such as wider absorption range, low-pressure drop, generator cooling, nuclear system cooling, good thermal conductivity, heat exchangers, etc. In this article, the impact of variable magnetic field on the flow field of hybrid nano-fluid for the improvement of heat and mass transmission is investigated. The main objective of this study is to see the impact of hybrid nano-fluid (ferrous oxide water and carbon nanotubes) CNTs-Fe3O4, H2O between two parallel plates with variable magnetic field. The governing momentum equation, energy equation, and the magnetic field equation have been reduced into a system of highly nonlinear ODEs by using similarity transformations. The parametric continuation method (PCM) has been utilized for the solution of the derived system of equations. For the validity of the model by PCM, the proposed model has also been solved via the shooting method. The numerical outcomes of the important flow properties such as velocity profile, temperature profile and variable magnetic field for the hybrid nanofluid are displayed quantitatively through various graphs and tables. It has been noticed that the increase in the volume friction of the nano-material significantly fluctuates the velocity profile near the channel wall due to an increase in the fluid density. In addition, single-wall nanotubes have a greater effect on temperature than multi-wall carbon nanotubes. Statistical analysis shows that the thermal flow rate of (Fe3O4-SWCNTs-water) and (Fe3O4 -MWCNTs-water) rises from 1.6336 percent to 6.9519 percent, and 1.7614 percent to 7.4413 percent, respectively when the volume fraction of nanomaterial increases from 0.01 to 0.04. Furthermore, the body force accelerates near the wall of boundary layer because Lorentz force is small near the squeezing plate, as the current being almost parallel to the magnetic field.The work of U.F.-G. has been supported by the government of the Basque Country for the ELKARTEK21/10 KK-2021/00014 and ELKARTEK20/78 KK-2020/00114 research programs, respectively

    Electroviscous Effect of Water-Base Nanofluid Flow between Two Parallel Disks with Suction/Injection Effect

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    This article, investigates the behaviour of an ionized nanoliquid motion regarding heat transmission between two parallel discs. In the proposed model, the squeezing flow of Cu-water nanofluid with electrical potential force is analysed for studying the flow properties and an uniform magnetic field is applied to that fluid, by taking the surface of the bottom disc porous. We have also studied the effects of different nanomaterials on the transmission of heat through nanofluids. Furthermore, the influence of various physical parameters in the proposed model of nanofluids flow like volume fraction of nanomaterials, squeezing number, Hartmann number, Eckert number, and Prandtl number are analysed and discussed quantitatively through various tables and graphs. The system of nonlinear partial differential equations (PDE’s) has been used to formulate the proposed flow model and later converted to a set of nonlinear ODE’s by mean similarity transformation. Further, the reduced form of ODEs has been solved by Parametric Continuation Method (PCM), which is a stable numerical scheme. The outcomes obtained from the proposed model could also be used to analyse nanofluid flow in several fields, such as polymer processing, power transfer and hydraulic lifts.We acknowledge the insightful comments of the editorial board to make this work more beautiful. We also acknowledge the financial support provided by the Postdoctoral research support fund of School of Mathematical Sciences, Jiangsu University, Zhenjiang, 212013, China. The work of U.F.-G. has been supported by the government of the Basque Country for the ELKARTEK21/10 KK–2021/00014 and ELKARTEK20/78 KK–2020/00114 research programs, respectively

    How to Relax in Stressful Situations: A Smart Stress Reduction System

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    Stress is an inescapable element of the modern age. Instances of untreated stress may lead to a reduction in the individual's health, well-being and socio-economic situation. Stress management application development for wearable smart devices is a growing market. The use of wearable smart devices and biofeedback for individualized real-life stress reduction interventions has received less attention. By using our unobtrusive automatic stress detection system for use with consumer-grade smart bands, we first detected stress levels. When a high stress level is detected, our system suggests the most appropriate relaxation method by analyzing the physical activity-based contextual information. In more restricted contexts, physical activity is lower and mobile relaxation methods might be more appropriate, whereas in free contexts traditional methods might be useful. We further compared traditional and mobile relaxation methods by using our stress level detection system during an eight day EU project training event involving 15 early stage researchers (mean age 28; gender 9 Male, 6 Female). Participants' daily stress levels were monitored and a range of traditional and mobile stress management techniques was applied. On day eight, participants were exposed to a 'stressful' event by being required to give an oral presentation. Insights about the success of both traditional and mobile relaxation methods by using the physiological signals and collected self-reports were provided
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