Measurement Of Sample Temperature Research Articles

A diamond anvil microassembly for Joule heating and electrical measurements up to 150 GPa and 4000 K

When diamond anvil cell (DAC) sample chambers are outfitted with both thermal insulation and electrodes, two cutting-edge experimental methods are enabled: Joule heating with spectroradiometric temperature measurement and electrical resistance measurements of samples heated to thousands of kelvin. The accuracy of temperature and resistance measurements, however, often suffers from poor control of the shape and location of the sample, electrodes, and thermal insulation. Here, we present a recipe for the reproducible and precise fabrication of DAC sample, electrodes, and thermal insulation using a three-layer microassembly. The microassembly contains two potassium chloride thermal insulation layers, four electrical leads, a sample, and a buttressing layer made of polycrystalline alumina. The sample, innermost electrodes, and buttress layer are fabricated by focused-ion-beam milling. Three iron samples are presented as proof of concept. Each is successfully compressed and pulsed Joule heated while maintaining a four-point probe configuration. The highest pressure-temperature condition achieved is ∼150 GPa and 4000 K.

Twofold increase in the sensitivity of Er3+/Yb3+ Boltzmann thermometer

Luminescence thermometry is the most versatile remote temperature sensing technique and can be employed from living cells to large surfaces and from cryogenic temperatures to the melting points of metals. Ongoing research aims to optimize the sensitivity of the ratio between the emission intensity from two coupled excited states. However, this approach is inherently limited to temperature-dependent processes involving only the excited states. Here, we develop a novel measurement technique, called luminescence intensity ratio squared (LIR2) for the Yb3+/Er3+ pair, that combines the temperature sensitivity of ground- and excited-state populations. We use Y3Al5O12:Er3+,Yb3+ nanoparticles as a promising model system with both visible and infrared emissions. To apply our method, we record two luminescence spectra at different excitation wavelengths and determine the LIR2 using one emission in each of the two spectra. The LIR2 testing with Y3Al5O12 nanoparticles showed a sensitivity increase of 70% in the visible region and an impressive 230% increase in the NIR region compared to the conventional LIR method. This enhances the measurement precision by a factor of 1.5–2.5. The LIR2 based on the visible upconversion emission is particularly useful for measurements of high temperatures, while the LIR2 based on the downshifted ∼1.5 μm emission may revolutionize temperature measurements of biological samples in the range of physiological temperatures.

Temperature measurement of aqueous solution in miniature sample chamber in microscopic system based on near-infrared spectrum.

Measurement of the sample temperature in biophysics research is challenging, as the samples are commonly placed in a miniature sample chamber under a microscope. In this study, we proposed a method to measure the temperature of an aqueous solution in miniature sample chambers in a microscopic system. Existing studies show that the absorption coefficient spectrum of water shifts with temperature, especially in the near-infrared (NIR) band. We measured the absorption spectra of water with different temperatures and analyzed them, to build a mathematical model relating the temperature and the spectrum. A setup for temperature measurement in a microscopic system was designed and implemented by coupling a spectrometer and a light source to a microscope. The temperature could be calculated by the spectral data and the mathematical model while simultaneously observing the micro-image of the sample. A series of liquid samples at different temperatures were tested using the setup, and the root mean square error of the calculated temperature is less than 0.5 °C. The results demonstrate that the method based on the NIR spectrum can be used for noncontact and quick measurement of the liquid sample temperature in a microscopic system.

Reconsidering the potential of micropyrolyzer to investigate biomass fast pyrolysis without heat transfer limitations

Commercial analytical pyrolysis systems have become increasingly used in biomass fast pyrolysis research. Establishing experimental conditions free from heat transfer limitations using these micro-rectors has not been verified. Since accurate measurement of biomass sample temperature with these devices is not possible, the isothermal character of experiments has never been verified. In this work, numerical simulations were conducted to assess the time-temperature history of both cup and different sample arrangements and to determine the overall heat transfer coefficients at the surface of the biomass samples to confirm the pyrolysis regime based on the dimensionless analysis in the micropyrolyzer. Using both a small mass of biomass sample (≤ 50 μg) carefully arranged at the bottom of the cup and a temperature below 723 K allows the complete elimination of heat transfer limitations within the micropyrolyzer. The heating time of the biomass sample was significant (4–5 s to reach 773 K), proving that the experiment is not isothermal. Thus, evaluating the kinetics of biomass fast pyrolysis requires establishing the time-temperature history of the sample, as an essential prerequesite. Both heating profiles of biomass samples arranged in thin-film and torus were found to follow that of the cup; the time-temperature history of the sample can be determined by measuring the temperature of the cup.

Investigations of Model Multilayer Ceramic Casting Molds in a Raw State by Nondestructive Methods.

This article presents the results of research on the use of modern nondestructive methods such as 3D scanning, thermography and computed tomography (CT) to assess the quality of multilayer ceramic molds. Tests were performed on spherical samples of multilayer ceramic molds in the raw state. Samples were made of molding sands composed of quartz and molochite powders, the alcoholic binder hydrolyzed ethyl silicate (ZKE) and an aqueous binder based on colloidal silica. Thickness measurements of spherical forms were made using a 3D scanner. Porosity measurements were made using CT. Additionally, thermography observations of the mold cooling process were made with controlled temperature and humidity. The results of temperature measurements of samples were compared with measurements of thickness and porosity. The practical goal was to determine the possibility of using thermography, 3D scanning and CT as a quick method for detecting mold defects by varying their thickness, porosity and cracks and for final verification of the ceramic molds’ condition before casting.

2-D Noninvasive Temperature Measurement of Biological Samples Based on Compressive Thermoacoustic Tomography

There is a great need in temperature monitoring in biomedical applications. The current available temperature measurement techniques have some deficiencies in noninvasiveness, applicability, sensitivity and resolution. Microwave-induced thermoacoustic tomography (MITAT) has found diversified applications in biomedical related disciplines. It has been shown that MITAT can be used to estimate the temperature in a noninvasive manner. However, the applicability of the technique is still limited. This work presents experimental demonstration of two-dimensional (2-D) temperature detection of biological samples based on compressive TAT, referred to as MICTAT. Detailed principle of the method is established. A phantom sample and a biological sample are tested by experiments and 2-D temperature maps are obtained. This work provides a new route of getting 2-D temperature maps of biological samples and may find many applications in biomedical related areas.

Enhancement and Discontinuity of Effective Mass through the First-Order Metamagnetic Transition in UTe2

Metamagnetic transitions in the novel spin-triplet superconductor UTe$_2$ were investigated through the newly developed simultaneous measurements of magnetization and sample temperature for the field along the orthorhombic $b$-axis and close to the [011] direction, where reentrant superconductivity (RSC) is detected below and above the first-order metamagnetic transition field $H_{\rm m}$. Combining the Maxwell's relation and the Clausius-Clapeyron equation, we obtained the field dependence of Sommerfeld coefficient $\gamma$ through the first-order metamagnetic transition. A significant enhancement of the effective mass toward $H_{\rm m}$ were detected for both field directions. On the other hand, above $H_{\rm m}$, the effective mass discontinuously decreases for $H~||~b$, while it discontinuously increases for $H~||~\sim [011]$, which seems to make a crucial role for the RSC.

A novel experimental setup for the determination of the thermal expansion coefficient of concrete at cryogenic temperatures

This article presents the design of a test device for cryogenic testing of concrete samples. Cryogenic tests consisted of compression and expansion tests of liquid nitrogen on cylindrical concrete specimens and their scope was to determine the linear coefficient of thermal expansion of the concrete material at temperatures from zero to minus 160° C. This article presents a design. Τhe test chamber and the new strategies that were used; along with the corresponding challenges posed by the heating and measurement problems. Affected heat transfer transient and steady state problems, which were realized using digital analysis using commercial FEM software, are presented along with the measurement equipment and methods that were used to match the numerically calculated temperature profiles along with the measured ones. In addition, the sample temperature measurement topology that was chosen for the experiments is compared with conventional ones in their ability to provide information representing the temperature state of the sample. Finally, the raw data from three tests are analyzed and the results are presented in appropriate graphs, taking into account the systematic errors introduced by thermal compression of the metrological equipment used for measuring length. The results are consistent with those available in the concrete literature.

Quantifying Real-Time Sample Temperature Under the Gas Environment in the Transmission Electron Microscope Using a Novel MEMS Heater.

Accurate control and measurement of real-time sample temperature are critical for the understanding and interpretation of the experimental results from in situ heating experiments inside environmental transmission electron microscope (ETEM). However, quantifying the real-time sample temperature remains a challenging task for commercial in situ TEM heating devices, especially under gas conditions. In this work, we developed a home-made micro-electrical-mechanical-system (MEMS) heater with unprecedented small temperature gradient and thermal drift, which not only enables the temperature evolution caused by gas injection to be measured in real-time but also makes the key heat dissipation path easier to model to theoretically understand and predict the temperature decrease. A new parameter termed as “gas cooling ability (H)”, determined purely by the physical properties of the gas, can be used to compare and predict the gas-induced temperature decrease by different gases. Our findings can act as a reference for predicting the real temperature for in situ heating experiments without closed-loop temperature sensing capabilities in the gas environment, as well as all gas-related heating systems.

In-depth wood temperature measurement using embedded thin wire thermocouples in cone calorimeter tests

In-depth temperature measurements of wood samples using thermocouples are commonly performed in fire research at all scales. However, the size or the type of thermocouples or how they are placed in the sample can lead to the measured temperature being significantly different. In this work, an original method combining thin wire thermocouples with a meticulous implantation, was used to provide an accurate measurement of the in-depth temperature of wood samples during their degradation. Wood samples were thus equipped with both embedded thin wire thermocouples (0.1 mm diameter) and sheathed thermocouples (1 mm diameter) installed perpendicularly or in parallel to the conductive heat flux to compare the results between the two kinds of measurements. Afterwards, samples were exposed to the cone calorimeter at different heat fluxes (from 16.5 kW.m−2 to 93.5 kW.m−2) in order to measure both in-depth temperature and mass loss during the degradation. The smallness and high flexibility of thin embedded wire thermocouples enabled in-depth temperature measurement without affecting the mass loss measurement. This is usually not possible when using sheathed thermocouples, because of their high stiffness. Results showed that it is crucial to rigorously control the thermocouple implantation, as an underestimation up to was observed for thermocouples put near the surface exposed to the heat flux. There are several reasons for this difference: the heat sink due to conductive heat flux through the thermocouple body, a poor contact between the sensor and the sample and uncertainty about the actual position of the thermocouple. The char front evolution deduced from temperature measurement by wire thermocouples was found to comply with direct measurements of the char layer performed on samples. Finally, the charring rate obtained from in-depth temperature as a function of the heat flux was found to follow an affine law.

SiCTeC: An inexpensive, easily assembled Peltier device for rapid temperature shifting during single-cell imaging.

Single-cell imaging, combined with recent advances in image analysis and microfluidic technologies, have enabled fundamental discoveries of cellular responses to chemical perturbations that are often obscured by traditional liquid-culture experiments. Temperature is an environmental variable well known to impact growth and to elicit specific stress responses at extreme values; it is often used as a genetic tool to interrogate essential genes. However, the dynamic effects of temperature shifts have remained mostly unstudied at the single-cell level, due largely to engineering challenges related to sample stability, heatsink considerations, and temperature measurement and feedback. Additionally, the few commercially available temperature-control platforms are costly. Here, we report an inexpensive (<$110) and modular Single-Cell Temperature Controller (SiCTeC) device for microbial imaging—based on straightforward modifications of the typical slide-sample-coverslip approach to microbial imaging—that controls temperature using a ring-shaped Peltier module and microcontroller feedback. Through stable and precise (±0.15°C) temperature control, SiCTeC achieves reproducible and fast (1–2 min) temperature transitions with programmable waveforms between room temperature and 45°C with an air objective. At the device’s maximum temperature of 89°C, SiCTeC revealed that Escherichia coli cells progressively shrink and lose cellular contents. During oscillations between 30°C and 37°C, cells rapidly adapted their response to temperature upshifts. Furthermore, SiCTeC enabled the discovery of rapid morphological changes and enhanced sensitivity to substrate stiffness during upshifts to nonpermissive temperatures in temperature-sensitive mutants of cell-wall synthesis enzymes. Overall, the simplicity and affordability of SiCTeC empowers future studies of the temperature dependence of single-cell physiology.

Study on the Complete Decarburization of Spring Steel 55SiCrA during Rolling

The rolling test of 55SiCrA spring steel wire rod was carried out with different finishing rolling temperature and laying temperature. The results show that different rolling processes can form different types of complete decarburization. Through temperature measurement and metallographic examination of process samples, it is found that the surface of the rolled piece has formed a complete decarburization layer during the rolling process. However, by setting proper finishing rolling temperature and laying temperature, the deformation heat of high-speed rolling can transform complete decarburization into austenite and avoid complete decarburization of 55SiCrA spring steel wire rod.

Two-step-pressurization method in pulsed electric current sintering of MoO3 for production of 99mTc radioactive isotope

ABSTRACT Pulsed electric current sintering of molybdenum trioxide (MoO3) was carried out by one- and two-step pressurization methods for fabrication of irradiation targets used in the production of 99Mo and 99mTc nuclear medicines. At 550°C by the two-step pressurization method, a relative density of 93.1% was obtained while, by the one-step pressurization method, the relative density was 76.9%. Direct sample temperature measurements were conducted by a thermocouple inserted in a punch. By the two-step pressurization method, the sample temperature was higher than that by the one-step pressurization method even at almost the same die temperature. From voltage and current waveforms, it was indicated that the conductivity of the sample increased by the two-step pressurization method to increase the sample temperature and the relative density. The two-step pressurization method allows us to prepare dense targets at a low temperature from recycled and coarse-grained 98Mo enriched MoO3 powder.

The dual advanced ion simultaneous implantation experiment (DAISIE) for testing plasma-facing materials

A new dual ion beam experimental facility, the Dual Advanced Ion Simultaneous Implantation Experiment (DAISIE), has been constructed at the University of Wisconsin-Madison Inertial Electrostatic Confinement laboratory for implanting candidate plasma-facing components of multiple ion species. DAISIE is capable of implanting ions at energies from 10 kV to 50 kV, ion currents of 10 µA–950 µA, corresponding to steady-state ion fluxes of 1 × 1014 cm−2 s−1 to 1 × 1016 cm−2 s−1, incidence angles of 55°, and surface temperatures of at least 1100 °C. Improvements to the sample current and sample temperature measurement and control systems over those used in prior UW-IEC experiments have been made. Optical measurements of the spot size of the beam on samples in DAISIE are in agreement with existing measurements of the ion beam and spot size in previous UW-IEC experiments. Dual-beam operation has been confirmed with helium-deuterium ion implantations in tungsten surfaces.

Effective conductivity of porous ceramics in a radiative environment

The knowledge of the effective thermal conductivity, taking into account conduction and radiation, is crucial for the accurate prediction of the thermal behavior of porous foams, especially in an environment where radiation is dominating. We present a combined experimental-numerical method for the quantification of the temperature-dependent effective thermal conductivity of porous ceramics. The experiments include transient and spatially-resolved temperature measurements of ceramic foam samples with porosities between 75% and 92%, exposed to high radiative fluxes (peak of 1500 kW.m−2). Maximum surface temperatures of 1900K for high purity alumina samples and of 1500K for alumino-silicate (AS) samples were measured, and nonlinear temperature profiles through the sample along the main temperature gradient direction were measured. A 3D numerical model based on an OpenFOAM toolbox was developed and used to determine the thermal conductivity, using the experimental temperature measurements as input. We quantified the effective thermal conductivities (ETCs) in a temperature range of 288–1473K and showed that the ETC of AS samples can significantly increase in the presence of incoming and internal radiation. Alumina with 2 to 5 times smaller typical pore sizes (80 μm vs 190 μm, 230 μm, and 400 μm) exhibited an ETC dominated by conduction and relatively unaffected by radiation. This work illustrates that the ETC of porous materials exposed to radiative fluxes do not only depend on material properties or morphology but also on the operational conditions.

Refractive index sensing with temperature compensation by a multimode-interference fiber-based optical frequency comb sensing cavity.

We proposed a refractive index (RI) sensing method with temperature compensation by using an optical frequency comb (OFC) sensing cavity including a multimode-interference (MMI) fiber, namely, the MMI-OFC sensing cavity. The MMI-OFC sensing cavity enables simultaneous measurement of material-dependent RI and sample temperature by decoding from the comb spacing frequency shift and the wavelength shift of the OFC. We realized the simultaneous and continuous measurement of RI-related concentration of a liquid sample and its temperature with precisions of 1.6 × 10-4 RIU and 0.08 °C. The proposed method would be a useful means for the various applications based on RI sensing.

An Optical Diffraction Method for Controlling the Solid-Phase Recrystallization and Heating of Implanted Semiconductors during Pulse Light Annealing

t—The results of the improvement of the method of laser diagnostics for investigating the heating dynamics, solid-state recrystallization, and melting of implanted semiconductors directly during a pulse light annealing procedure are presented. This technique is based on recording Fraunhofer diffraction patterns from special periodic structures; it allows investigations of structural–phase transitions in ion-doped semiconductor layers simultaneously with sample temperature measurements with a high time resolution. For this purpose, two measuring diffraction gratings were preliminarily formed on the surface of a silicon wafer: a phase grating and an amplitude grating. The solid-phase recrystallization and melting processes were studied via the kinetics of the disappearance and appearance of the diffraction maxima from the amplitude grating. The sample temperature was monitored by the deflection of the diffraction angle of the probe laser beam from the phase diffraction grating. This deflection is caused by a change in the grating period due to its thermal expansion.

Optical clumped isotope thermometry of carbon dioxide

Simultaneous analysis of carbon dioxide isotopologues involved in the isotope exchange between the doubly substituted 13C16O18O molecule and 12C16O2 has become an exciting new tool for geochemical, atmospheric and paleoclimatic research with applications ranging from stratospheric chemistry to carbonate-based geothermometry studies. Full exploitation of this isotope proxy and thermometer is limited due to time consuming and costly analysis using mass spectrometric instrumentation. Here, we present an all optical clumped CO2 isotopologue thermometer with capability for rapid analysis and simplified sample preparation. The current development also provides the option for analysis of additional multiply-substituted isotopologues, such as 12C18O2. Since the instrument unambiguously measures all isotopologues of the 12C16O2 + 13C16O18O rightleftharpoons 13C16O2 + 12C16O18O exchange, its equilibrium constant and the corresponding temperature are measured directly. Being essentially independent of the isotope composition of the calibration gas, an uncalibrated working reference is sufficient and usage of international calibration standards is obsolete. Other isotopologues and molecules can be accessed using the methodology, opening up new avenues in isotope research. Here we demonstrate the high-precision performance of the instrument with first gas temperature measurements of carbon dioxide samples from geothermal sources.

Прямые измерения динамики электрокалорического отклика сегнетоэлектриков в условиях произвольного теплообмена

A new effective method for direct electrocaloric measurements under arbitrary heat exchange conditions is proposed. The accuracy and reliability of the sample temperature measurements in dynamic provided by the use of mid-IR photodiode temperature sensors with the possibility of the in-situ calibration procedure

MIRRORS: A MATLAB ® GUI for temperature measurement by multispectral imaging radiometry.

MultIspectRal imaging RadiOmetRy Software (MIRRORS) is an open source MATLAB based Graphical User Interface (GUI) designed to automatically process images generated from a four colour multispectral imaging radiometry system for the temperature measurement of samples heated in a diamond anvil cell. The GUI can work in either a live mode (during an experiment) or a post-processing mode and performs background subtraction, spatial correlation, and thermal calibration of the data before producing maps of temperature, emissivity, and their associated uncertainties, an image difference map (i.e., the change in the shape of the temperature field), and a variety of other visualisations derived from them. We describe the distribution, system requirements, and required hardware specific code modifications necessary to setup MIRRORS. We also describe the workflow of the software and its underlying methodologies and provide an example output as well as the results of benchmarking against a traditional spectroradiometric system of known accuracy.