3,825,887 research outputs found

    Effect of pyrolysis temperature on ochratoxin A adsorption mechanisms and kinetics by cashew nut shell biochars

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    Biochars were produced from cashew nut shell at 400, 600 and 800°C. Production temperature significantly affected biochar properties and consequently the adsorption mechanisms of ochratoxin A. Biochars produced at higher temperatures had significantly higher specific surface areas, resulting in higher OTA adsorption ca-pacities. The isotherms and kinetics of the adsorption were used to identify the adsorption mechanisms. For the kinetics study, experiments were carried out after adjustment of the parameters influencing the system, such as pH, biochar quantity and OTA initial concentration. Experimental results were modelled according to isotherm equations representing Langmuir model and Freundlich model. Langmuir model matched best with the experi-mental data. The chemical surface reaction was fitted to a pseudo-second order equation, with very high re-gression coefficients

    The effect of temperature during culture enrichment on methanotrophic polyhydroxyalkanoate production

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    Producción CientíficaClimate change and plastic pollution are likely the most relevant environmental problems of the 21st Century. Thus, one of the most promising solutions to remedy both environmental problems simultaneously is the bioconversion of greenhouse gases, such as methane (CH4), into bioplastics (PHAs). However, the optimization of this bioconversion platform is still required to turn CH4 biotransformation into a cost-effective and cost-competitive process. In this context, the research presented here aimed at elucidating the best temperature culture conditions to enhance both PHA accumulation and methane degradation. Six different enrichments were carried out at 25, 30 and 37 °C using different inocula and methane as the only energy and carbon source. CH4 biodegradation rates, specific growth rates, PHA accumulations and the community structure were characterized. Higher temperatures (30 and 37 °C) increased the PHAs accumulation up to 30% regardless of the inoculum. Moreover, Methylocystis became the dominant genus (∼30% of the total population) regardless of the temperature and inoculum used. This research demonstrated for the first time the fundamental role of temperature in increasing both the accumulation of PHAs and methane abatement during the enrichment of PHA cell-factories from methane, thus enhancing the cost-effectiveness of the process.Ministerio de Economía, Industria y Competitividad, TheEuropean FEDER program and the European Commission (CTM2015-73228-JIN, H2020-MSCA-IF-2016: CH4BioVal-GA:750126 and Red NOVEDAR)

    Effect of Temperature on PH Meter Based on Arduino Uno with Internal Calibration

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    PH Meter is a device used to express the level of acidity or basicity possessed by a substance or solution. Normal pH has a value of 7 while the pH value> 7 indicates that the substance has alkaline properties while the pH value <7 indicates acidic properties. pH 0 shows a high degree of acidity, and pH 14 shows the highest degree of alkalinity. pH Meter reads the pH and temperature values ​​in a sample. The author uses glass electrodes as a pH sensor, DS18B20 as a temperature sensor and LCD to make pH and temperature values. This module is equipped with an internal calibration that is used to set the module to read the pH value properly and correctly using a pH buffer and equipped with internal storage and this module facilitates battery usage. Based on pH measurements on the module the error value in buffer 4 calibration is 5.39%, in buffer 7 is 1.76%, in buffer 10 is 1.04%. The highest error value in the measurement sample is 3.54% and the lowest error value is 0.03%. The temperature of the sample is very influential on the reading of the pH value because the higher the temperature the pH value also increases even though it is not so significant

    Effect of temperature on Burkholderia pseudomallei growth, proteomic changes, motility and resistance to stress environments.

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    Burkholderia pseudomallei is a flagellated, gram-negative environmental bacterium that causes melioidosis, a severe infectious disease of humans and animals in tropical areas. We hypothesised that B. pseudomallei may undergo phenotypic adaptation in response to an increase in growth temperature. We analysed the growth curves of B. pseudomallei strain 153 cultured in Luria-Bertani broth at five different temperatures (25 °C-42 °C) and compared the proteomes of bacteria cultured at 37 °C and 42 °C. B. pseudomallei exhibited the highest growth rate at 37 °C with modest reductions at 30 °C, 40 °C and 42 °C but a more marked delay at 25 °C. Proteome analysis revealed 34 differentially expressed protein spots between bacterial cultures at 42 °C versus 37 °C. These were identified as chaperones (7 spots), metabolic enzymes (12 spots), antioxidants (10 spots), motility proteins (2 spots), structural proteins (2 spots) and hypothetical proteins (1 spot). Of the 22 down-regulated proteins at 42 °C, redundancy in motility and antioxidant proteins was observed. qRT-PCR confirmed decreased expression of fliC and katE. Experiments on three B. pseudomallei strains demonstrated that these had the highest motility, greatest resistance to H2O2 and greatest tolerance to salt stress at 37 °C. Our data suggest that temperature affects B. pseudomallei motility and resistance to stress

    Effect of Substrate Temperature and Target-Substrate Distance on Growth of TiO2 Thin Films by Using DC- Reactive Sputtering Technique

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    Titanium oxide (TiO2) thin films have been deposited by a DC sputtering technique onto microscope glass slides. The effect of substrate temperature (Ts) and target-substrate distance (Dts) on some optical and electrical properties have been studied each individually. The structure of TiO2 thin films has been improved and became more crystalline when Ts has been increased (from 150 ºC to 250 ºC). The conductivity (ϭ), deposition rate (DR) and average values of grain size (G.S) have been increased with increasing Ts while the values of band gap (Eg) and weight percentage of the anatase phase (WA) have been decreased. The thickness of TiO2 film has been increased from 920 nm to 960 nm with increase Ts while it has been decreased from 960 nm to 680 nm with increase Dts (from 25mm to 35mm). As Dts has been increased, the conductivity ϭ, thickness (d) and average values of grain size have been decreased. The decreasing of conductivity at Dts=35 maybe attributes to increase the weight percentage of the rutile phase (WR). The XRD results show that the TiO2 structure phase has been varied. The results show that the optical and electrical properties of TiO2 film affected by changes the condition parameters especially Ts and Dts as well as the density and energy of the impinging atoms. The surface morphology and component of TiO2 thin films, resistance, optical transmittance and structure of film were characterized by SEM (EDX), I-V meter, UV-VIS spectrophotometer and XRD respectively

    Room Temperature Reversible Spin Hall Effect

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    Reversible spin Hall effect comprising the "direct" and "inverse" spin Hall effects was successfully detected at room temperature. This experimental demonstration proves the fundamental relations called Onsager reciprocal relations between spin and charge currents. A platinum wire with a strong spin-orbit interaction is used not only as a spin current absorber but also as a spin current source in the present lateral structure specially designed for clear detection of both charge and spin accumulations via the spin-orbit interaction. The obtained spin Hall conductivity is much larger than the reported value of Aluminum wire because of the larger spin-orbit interaction.Comment: 12 pages, 4 figure

    The Sachs-Wolfe Effect: Gauge Independence and a General Expression

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    In this paper we address two points concerning the Sachs-Wolfe effect: (i) the gauge independence of the observable temperature anisotropy, and (ii) a gauge-invariant expression of the effect considering the most general situation of hydrodynamic perturbations. The first result follows because the gauge transformation of the temperature fluctuation at the observation event only contributes to the isotropic temperature change which, in practice, is absorbed into the definition of the background temperature. Thus, we proceed without fixing the gauge condition, and express the Sachs-Wolfe effect using the gauge-invariant variables.Comment: 5 pages, closer to published versio

    Large magnetoresistance at room-temperature in semiconducting polymer sandwich devices

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    We report on the discovery of a large, room temperature magnetoresistance (MR) effect in polyfluorene sandwich devices in weak magnetic fields. We characterize this effect and discuss its dependence on voltage, temperature, film thickness, electrode materials, and (unintentional) impurity concentration. We usually observed negative MR, but positive MR can also be achieved under high applied electric fields. The MR effect reaches up to 10% at fields of 10mT at room temperature. The effect shows only a weak temperature dependence and is independent of the sign and direction of the magnetic field. We find that the effect is related to the hole current in the devices.Comment: 3 pages, 4 figure

    Effect of Temperature on Wetting Angle

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