Influence Of Temperature Variation Research Articles

PENGARUH TEMPERATUR EKSTRAKSI ZAT WARNA ALAM DAUN JATI TERHADAP KUALITAS DAN ARAH WARNA PADA BATIK

Negative impacts especially synthetic dye carcinogenic effect on the environment and the user so natural coloring is now starting to be used because environmentally friendly. The influence of temperature variations on the quality and color direction using natural color teak leaves for batik cloth needs to be examined because the color of the fabric will decline due pelorodan process. The young leaves teak (Tectona grandis) have a wide and large size, used to dye woven materials, have reddish brown color. The method used was variation temperature extraction of 50°C, 75°C and 100°C, fixation of alum, lime, prusi and lotus as well as testing the quality and direction of color. Variations in temperature extraction of teak leaves on cotton fabric and silk using a waterbath expected to know the quality and direction of the colors in batik. Results of testing the fastness to light and washing 40°C for extraction of teak leaf temperature of 50°C, 75°C and 100°C in cotton and silk with fixation alum, lime, prusi or lotus shows good scale with a value of 4 or 4-5. Natural color solution teak leaves with extraction temperature of 100°C resulted in the highest wavelength is 788.50 nm and the absorbance of the total of 0.1402 Abs. Color direction that produced show reddish color will be more visible at 100°C with a fixation alum or lime while prusi or lotus browned .

Numerical Simulation for Hot Dry Rock Geothermal Well Temperature Field

Study on temperature distribution simulation during cementing of hot dry rock (HDR) geothermal well is rare. It has important guiding significance to simulate the construction process of temperature distribution of hot dry rock on site construction. Based on numerical simulation of HDR considering heat-fluid-solid coupling, the influence of temperature distribution on well cementing is analyzed when the drilling fluid cycles and reaches stable state, respectively, and when the cement slurry is injected during the cementing process. It is found that the seepage at the well bottom accelerates the flow velocity of wellbore; the stable temperature change is less than the cyclic temperature change; and the upper and lower temperature variation of the stratum is greater when the cement slurry is injected. Therefore, as to cement retarder involved, the influence of temperature variation on concretion should be considered during cementing of the hot dry rock geothermal well.

Multivariable tuning of the magnetostructural response of a Ni-modified FeRh compound

The magnetostructural response of a Ni-modified B2-type FeRh compound of composition, (Fe47.5Ni1.5)Rh51, is reported under the influence of simultaneous variations in temperature, applied magnetic field and hydrostatic pressure. The material undergoes a first-order magnetic transition from the antiferromagnetic state to the ferromagnetic state at a reduced temperature Tt = 144 K in the absence of applied magnetic field μ0H and applied pressure P. Applied independently, pressure and magnetic field influence Tt in opposite ways, with [dTt/dH]P=0 = −24 K/T and [dTt/dP]H=0 = 15 K/kbar, which are 3 time larger than in the parent compound FeRh. Application of Maxwell's relations to the magnetization data allows determination of the entropy change of the compound, and thus evaluates its magnetocaloric potential through the transition. Pressure application increases the magnetic entropy change (ΔSmag) but decreases the width of the magnetostructural transition, thereby decreasing the refrigeration capacity. Application of pressure also drives the phase transition to lower temperatures; it becomes sluggish and eventually is completely arrested below a critical temperature of ∼75 K. A three-dimensional (μ0H–P–T) phase diagram is constructed for the magnetic transition in the (Fe47.5Ni1.5)Rh51 system in order to evaluate the isocompositional magnetostructural response to combined application of pressure and magnetic field. Overall, these results emphasize that the magnetostructural phenomena in FeRh-based compounds is a thermally-activated process that may be tuned predictably by a variety of intrinsic (elemental substitution) and extrinsic (pressure, magnetic field, temperature) factors.

The influence of temperature to a refractive index sensor based on a macro-bending tapered plastic optical fiber

Abstract The temperature influence to a refractive index (RI) sensor based on a macro-bending tapered plastic optical fiber (POF) was investigated experimentally. The total temperature dependence loss (TDLtotal) and total temperature dependence RI deviation (TDRtotal) were measured at different temperature (10–60 °C) over an RI range of 1.33–1.41. The temperature dependence RI deviation of the sensor itself was obtained by subtracting the temperature dependence RI of measured liquid from TDRtotal. Therefore, the influence of temperature variation to the sensor was characterized and corrected.

Water Detection Using Bi-Wires as Sensing Elements: Comparison Between Capacimetry-Based and Time-of-Flight-Based Techniques

It is known that bi-wires can be employed as passive distributed sensing elements (SEs), to accurately locate water infiltrations in soil, concrete materials, and so on, using the standard time-domain reflectometry instrumentation and proper signal processing. This paper examines the possibility of using the same kind of SEs with simpler techniques and cheaper hardware, in order to trigger an alert in the case of water infiltrations. Two techniques are examined: the first measures the SE capacitance, and the second measures the time-of-flight of electromagnetic waves in the SE. The performance of the techniques is comparatively evaluated, in terms of sensitivity to the presence of water and the influence of temperature variations. The capacitance-based technique is found to be more sensitive to the presence of water, but also more prone to the influence of temperature, as long as the temperature variations are of modest entity (below 10 °C). For higher temperature variations, the capacimetric method appears to be advantageous. The results of this paper are useful to practically implement the monitoring of water leaks in a large set of buried pipes, water infiltrations in a large concrete structure, and so on.

Novel Evaluation Method of Foam Agents for Thermal Recovery in Heavy Oil Reservoirs

Aiming at the influence of temperature on foaming ability and blocking characteristics during steam injection, a study is carried out to establish a new evaluation method of foaming agents at variable temperatures in a heavy oil reservoir. The method synthetically considers the influence of temperature variation on the foaming ability, foam stability, and resistance factor by introducing some important parameters, such as the average foam comprehensive index, the average foam resistance factor, the weighted factor, and the comprehensive value of foam performance. In the laboratory, five foaming agents are quantificationally evaluated according to the method introduced in this article. The experimental results indicate that agent A, ZWF-1, is the optimum foaming agent in terms of the order of the dimensionless evaluation parameters. Aiming at an actual well group of an oilfield from China, the pilot test of foam profile control is implemented. The practice results show that the cumulative incremental oil p...

Influence of temperature variation on field effect transistor properties using a solution-processed liquid crystalline semiconductor, C8BTBT

ABSTRACTIn this study, we used a LC semiconductor, C8BTBT, solution (e.g. 0.1 wt % in heptane) for forming an organic semiconductor layer by casting method, and fabricated bottom-gate/bottom-contact type FETs. The FETs mobility was determined 0.17 cm2 V−1 s−1 which was comparable to that determined by time-of-flight technique in a sandwich type cell at room temperature. We have investigated the surface morphology and the influence of temperature variation on FET properties. The LC FET mobility was kept below 60°C and drastically decreased after heat stress above 100°C irreversibly.

Influence of Temperature Variation on Field Effect Transistor Properties Using a Solution-Processed Liquid Crystalline Semiconductor, 8TNAT8.

In this study, we used a liquid crystalline (LC) semiconductor, 8TNAT8, solution (e.g., 0.1 wt% in toluene) for forming an organic semiconductor layer by solution casting method, and fabricated bottom-gate/bottom-contact type field effect transistors (FETs). These LC semiconductors show FET characteristic properties and have high carrier mobility of 0.01 cm2 V-1 s-1. We have investigated the surface morphology and the influence of temperature variation on LC FET properties across the phase transition from crystal to mesophase of a LC semiconductor, 8TNAT8. In the most cases, FET mobility was irreversibly decreased after. temperature heat stress above the melting point of 8TNAT8, owing to the morphological change of LC layer.

Experimental investigations of the soil–concrete interface: physical mechanisms, cyclic mobilization, and behaviour at different temperatures

Behaviour of the pile–soil interface is important to correctly predict the response of floating piles in terms of displacement and lateral friction. Regarding energy piles, which couple the structural roles of deep foundations with the principle of shallow geothermal energy, the response of pile–soil interfaces is influenced by seasonal and daily cyclic thermal variations. Accordingly, the goal of this paper is to experimentally investigate the response of the pile–soil interface at different temperatures. This experimental campaign aims to analyse (i) the cyclic mobilization of the shear strength of the soil–pile interface that is induced by thermal deformation of the pile and (ii) the direct influence of temperature variations on the soil and soil–pile interface behaviour. In this study, a direct shear device was developed and calibrated for nonisothermal soil–structure interface testing. It appears that the sand–concrete interface was affected by cyclic degradation but not affected directly by temperature. Conversely, the response of the clay–concrete interface changed at different temperatures, showing an increase of strength with increasing temperature, presumably due to the effects of temperature on clay deformation.

Generation of second harmonic light with a wavelength of 560 nm in a compact module

We demonstrate a continuous wave 133mW laser module at 560.5nm on a 50mm·10mm optical bench. The setup consists of a 1121nm distributed Bragg reflector ridge waveguide laser and a MgO:LiNbO3 quasi-phase matched ridge waveguide crystal, which are coupled by a grin lens, as well as two cylindrical lenses for beam collimation behind the crystal. A novel approach to ensure phase matching is used. The laser and the crystal are stabilized by the same heat sink and only the wavelength of the laser is tuned by heating the distributed Bragg reflector section of the laser. This reduces the influence of temperature variations on the module's performance enabling operation with output power variations <10% over a temperature range of 20K. The size and robustness against temperature variations of this setup make it an interesting candidate for future biomedical applications.

SHM of bridges: characterising thermal response and detecting anomaly events using a temperature-based measurement interpretation approach

A major bottleneck preventing widespread use of Structural Health Monitoring (SHM) systems for bridges is the difficulty in making sense of the collected data. Characterising environmental effects in measured bridge behaviour, and in particular the influence of temperature variations, remains a significant challenge. This paper proposes a novel data-driven approach referred to as Temperature-Based Measurement Interpretation (TB-MI) approach to solve this challenge. The approach is composed of two key steps—(1) characterisation of thermal effects in bridges using a methodology referred to as Regression-Based Thermal Response Prediction (RBTRP) methodology, and (2) detection of anomaly events by analysing differences between measured and predicted structural behaviour. Measurements from a laboratory truss structure that is setup to simulate a range of structural scenarios are employed to evaluate the performance of the TB-MI approach. The study examines how the predictive capability of the RBTRP methodology is influenced by dimensionality reduction and measurement down-sampling, which are common pre-processing techniques used to deal with high spatial and temporal density in measurements. It also proposes a novel anomaly detection technique referred to as signal subtraction method that detects anomaly events from time-series of prediction errors, which are computed as the difference between in situ measurements and predictions obtained using the RBTRP methodology. Results demonstrate that the TB-MI approach has potential for integration within data interpretation frameworks of SHM systems of full-scale bridges.

The Behaviour of Linear Timber Structural Elements Subjected to the Combined Action of Force Systems and Temperature Variations

The mechanical properties of wood elements can be influenced by any combination between loads, humidity, temperature variations, biological actions and other factors.The present paper focuses on the study of the influence of temperature variations on the strength and deformability capacity of bar type wood elements with rectangular cross-section. The analysis was performed for different support conditions, under 12% constant humidity.Firstly, the authors propose a comparative analysis between the state of stresses and strains of the bar type wood elements computed using analytical methods and a numerical application. For the numerical determination SAP2000 structural analysis and design software was used.In the second part of the article the influence of temperature variations on the wood elements is evaluated, with considerations upon the risk of exceeding the resistance capacity and deformability.

Design of a Hot-wire Rake for Measurements in Temperature-varying Flow Fields

The present work deals with the design of a multi-probe support for simultaneous multi-point measurements. The article analyses the effects of the insertion of a hot-wire rake in a test section where the flow shows not constant temperatures. The constant temperature anemometry technique is known to have a relevant sensibility to both fluid temperature variations during the measurements and temperature differences between calibration and testing conditions. Therefore a technique to take into account for the flow temperature drifts influence is proposed and validated. The temperature correction presented allows reducing the influence of temperature variations on the measured velocity. This is achieved introducing a correction term, namely the temperature-loading factor that can be optimized for the individual probe and measurement conditions. The correction also takes into account for variations in fluid property values (Prandtl number, dynamic viscosity, heat conductivity and density) with temperature.

Impact of temperature on the aging mechanisms of arsenic in soils: fractionation and bioaccessibility.

The present study focused on the influence of temperature variation on the aging mechanisms of arsenic in soils. The results showed that higher temperature aggravated the decrease of more mobilizable fractions and the increase of less mobilizable or immobilizable fractions in soils over time. During the aging process, the redistribution of both carbonate-bound fraction and specifically sorbed and organic-bound fraction in soils occurred at various temperatures, and the higher temperature accelerated the redistribution of specifically sorbed and organic-bound fraction. The aging processes of arsenic in soils at different temperatures were characterized by several stages, and the aging processes were not complete within 180 days. Arsenic bioaccessibility in soils decreased significantly by the aging, and the decrease was intensified by the higher temperature. In terms of arsenic bioaccessibility, higher temperature accelerated the aging process of arsenic in soils remarkably.

On the effects of uniform temperature variations on stay cables

The present paper is concerned with the analysis of thermal effects on both static and dynamic mechanical behaviors of inclined elastic stay cables used in cable-stayed structures. Based on the elastic catenary cable theory, a nonlinear analytical approach is proposed in order to calculate variations of stay cables’ tensions under uniform temperature changes. Making use of simplifying assumptions, the influence of temperature variations on the free undamped vibration of stay cables is also investigated. The validity and the effectiveness of the proposed approach are demonstrated by comparing model results with monitoring data measured on stay cables of the Rades-La Goulette cable-stayed bridge in Tunisia.

Design and simulations of a new biaxial silicon resonant micro-accelerometer

This paper presents a new biaxial silicon resonant micro-accelerometer. The device basically consists of a single proof mass, four pairs of decoupled beams, four lever mechanisms and two pairs of resonators, which provides 2-D in-plane acceleration measurement with the decoupled two pairs of resonators. Structure optimization is implemented by taking advantage of the finite element analyses. From the simulation results we can see that the effective frequencies of two acceleration sensitive modes are 1010.18 and 1010.13 Hz respectively, and the undesired modes and effective modes are isolated apparently. Additionally, high linear relationship between the input acceleration and the resonant frequency shifts of resonators are demonstrated by the input---output characteristic simulation. Moreover, simulation results reveal the scale factor for the x-axis is 180.03 Hz/g, and the scale factor for y-axis is 180.75 Hz/g, while the cross-axis sensitivity for x-axis is 0.046 Hz/g, and the cross-axis sensitivity for y-axis is 0.027 Hz/g. The high sensitivity and low cross-axis sensitivity are thus adequately confirmed. By the way, the simulation of temperature dependent characteristics demonstrate that the differential scheme can effectively suppress the influence of temperature variation, and the thermal analysis shows that the device can bear the thermal stress induced by temperature change. All these simulations above can verify the feasibility of the structure design.

Seasonality in anuran activity and calling season in a Brazilian subtemperate wetland

Most tropical regions have a climate characterized by marked seasonal rainfall patterns, and these seasonal patterns of rainfall directly affect anuran activity. However, in regions with temperate climates, the main aspect of climate related to anuran activity is the thermal regime. Thus, transitional climate regions represent good opportunities to study the effect of abiotic factors on anuran activity. In this study, we present new data on the activity pattern and calling season of Neotropical anurans in a subtemperate climate. Anuran activity was assessed based on the rate of capture of specimens in pitfall traps and calling surveys. The field study was conducted between May 2010 and April 2011 in wetlands in southernmost Brazil. An analysis based on directional (circular) statistics showed that general activity in the studied anurans was significantly seasonal. In addition, the general activity pattern of most species was regulated by temperature, not by rainfall, and approached that observed in regions with a temperate climate. However, we did not record a well-defined peak in the number of species displaying calling activity. This parameter did not exhibit any influence of temperature variations or rainfall. The observed general activity pattern is different from that expected for the majority of anurans inhabiting eastern South America. The present study showed that the general activity patterns of most anurans in the wetland region in southernmost Brazil are regulated by temperature and not rainfall, similar to the pattern of anuran assemblies from temperate climates. However, the nonexistence of a significant relationship between calling activity and any of the environmental variables tested suggests the presence of a different environmental factor (e.g., photoperiod or the length of the hydroperiod of the relevant water bodies) as a trigger for the levels of general calling activity.

Study of the Effect of Linear and Parabolic Density Region in Settling Tanks for Potable Water

AbstractComputational fluid dynamics (CFD) methods are employed to evaluate the influence of temperature variations on the flow field in an actual sedimentation tank for potable-water treatment. A series of experimental measurements of temperature variation has been conducted in that sedimentation tank. The mixed-convection problem caused by the density variations and the horizontal stream is considered at low temperatures (0–10°C) where the variation of water density is strongly nonlinear. Three cases have been examined: (1) one in the ascending, (2) one in the descending parabolic density region, and (3) one in the linear density region. The thermophysical properties of water have been incorporated into the CFD code. All simulations have been conducted for a transient, turbulent flow field. The momentum exchange between the primary and the secondary phase (particles) is considered. The results show that in the parabolic density region, only a few particles are trapped in the bottom, whereas many of them...

An adaptive compensation algorithm for temperature drift of micro-electro-mechanical systems gyroscopes using a strong tracking Kalman filter.

We present an adaptive algorithm for a system integrated with micro-electro-mechanical systems (MEMS) gyroscopes and a compass to eliminate the influence from the environment, compensate the temperature drift precisely, and improve the accuracy of the MEMS gyroscope. We use a simplified drift model and changing but appropriate model parameters to implement this algorithm. The model of MEMS gyroscope temperature drift is constructed mostly on the basis of the temperature sensitivity of the gyroscope. As the state variables of a strong tracking Kalman filter (STKF), the parameters of the temperature drift model can be calculated to adapt to the environment under the support of the compass. These parameters change intelligently with the environment to maintain the precision of the MEMS gyroscope in the changing temperature. The heading error is less than 0.6° in the static temperature experiment, and also is kept in the range from 5° to −2° in the dynamic outdoor experiment. This demonstrates that the proposed algorithm exhibits strong adaptability to a changing temperature, and performs significantly better than KF and MLR to compensate the temperature drift of a gyroscope and eliminate the influence of temperature variation.

Pressure and temperature induced electrical resistance change in nano-carbon/epoxy composites

In this study, we investigate the changes of electrical resistance of the carbon black (CB) and carbon nanotube (CNT) filled epoxy composites upon compression, swelling and temperature variation. For all samples we observe a decrease of electrical resistance under compression, while an increase of electrical resistance is found upon swelling due to water absorption. With the same volumetric change, the CB/epoxy composites have a more pronounced change of electrical resistance than the CNT/epoxy composites. The influence of temperature variations on the overall electrical resistance is somewhat more complex. At low temperatures, electrical resistance clearly decreases with increasing temperature, mainly owing to the thermal fluctuation induced tunneling conduction mechanism. At high temperatures, electrical resistance decreases much slower and may even increase due to a more prominent thermal expansion effect. The thermal expansion of the epoxy matrix leads to a decrease of tunneling conduction. Without the contribution of the thermal expansion, the sensitivity and linearity of electrical resistance change upon temperature variations is higher.