Sample Temperature Research Articles

Design and development of a first order reversal curve measurement enabled variable temperature vibrating sample magnetometer

In this paper we present the design, construction and calibration of a sensitive vibrating sample magnetometer (VSM) and temperature variable setup with a capability to measure magnetization of magnetic materials from 100 K to 400 K with First Order Reversal Curve (FORC) measurement facility. It uses a bipolar power supply to energize an electromagnet capable of attaining ±1 Tesla field, subwoofer speaker for vibrating the sample and the induced voltage in four coil setup is measured by a lock-in amplifier. All hardware is controlled by a customized LabView program. The cryostat is designed such that the temperature can be varied continuously from 100 K to 400 K using liquid nitrogen up to room temperature and forced nitrogen gas/air for high temperatures study. We report here the VSM sensitivity of up to 10−2 emu/gm and can measure much weaker signals. The FORC protocol in this system is implemented via a dedicated virtual instrument in LabView capable of magnetic field reversal and termination at appropriate point to study domain nucleation field. The detailed analysis of the data is done using the open-source resources. We present the FORC measurement for Co0.5Zn0.5Fe2O4, a ferrimagnet. To establish the sensitivity of the instrument we present the results of magnetization measurement with temperature and phase transition study of La0.4Ca0.6MnO3 and La0.75Sr0.25MnO3.

A validated ballistic-He fuzz-growth model for high temperature erosive-plasma regimes

An analytical model of helium-induced fuzz growth on heated tungsten (Patino et al., 2023) is expanded to include the effects of material exposure temperature via an Arrhenius relation and helium-induced sputtering. The expanded model is able to replicate experimental measurements of fuzz thickness for a range of helium fluences from 0.7–110×1026 m−2, sample temperatures from 993–1300 K, and ion energies from 50–500 eV.

Evaluating the impact of filler size and filler content on the stiffness, strength, and toughness of polymer nanocomposites using coarse-grained molecular dynamics

Their great versatility makes polymer nanocomposites an important class of engineering materials. In order to gain detailed insights into the nanoscale mechanisms underlying their macroscopic mechanical properties, molecular dynamics (MD) simulations are a valuable tool to complement experimental studies. In this work, we modify the analytical potential functions of an efficient bead–spring model representing a generic polymer nanocomposite to account for the breaking of covalent bonds. We perform uniaxial tensile simulations of double-notched specimens and validate the model using experimental trends for overall stiffness, strength, and toughness. First, we study the effects of sample size, notch geometry, strain rate, temperature, and molar mass for the pure thermoplastic matrix material. Second, we analyze the influence of filler size and filler content on the mechanical behavior of the polymer nanocomposite. With this study, we show that in both the development of new materials and the optimization of established materials, it is possible to gain important preliminary insights into the effects of pertinent material characteristics with a simple MD setup, which can then be further refined by increasing the complexity of the material description and the boundary conditions.

Quantitative regulation of electron–phonon coupling

Electron–phonon (e–p) coupling plays a crucial role in various physical phenomena, and regulation of e–p coupling is vital for the exploration and design of high-performance materials. However, the current research on this topic lacks accurate quantification, hindering further understanding of the underlying physical processes and its applications. In this work, we demonstrate quantitative regulation of e–p coupling, by pressure engineering and in-situ spectroscopy. We successfully observe both a distinct vibrational mode and a strong Stokes shift in layered CrBr3, which are clear signatures of e–p coupling. This allows us to achieve precise quantification of the Huang–Rhys factor S at the actual sample temperature, thus accurately determining the e–p coupling strength. We further reveal that pressure efficiently regulates the e–p coupling in CrBr3, evidenced by a remarkable 40% increase in S value. Our results offer an approach for quantifying and modulating e–p coupling, which can be leveraged for exploring and designing functional materials with targeted e–p coupling strengths.

Preliminary study of mixing used cooking oil and lemon peel essential oil as an alternative fuel to replace biodiesel

Biodiesel is an environmentally friendly renewable bio-energy with many advantages over diesel fuel. The disadvantage of biodiesel is that the price is still relatively expensive so it cannot compete with diesel fuel. This high price is due to the high cost of raw materials and manufacturing process costs. Raw materials such as palm oil, methanol and methyl acetate are expensive, and the transesterification and interesterification processes require long process stages that require a lot of energy supply. The solution to overcome this problem is to use cheap raw materials and a simple manufacturing process. Used cooking oil is household waste that has prospects as a raw material. Another ingredient used is lemon essential oil. Lemon essential oil can be made yourself by extracting lemon peel waste using a boiling or steaming process. The lemon essential oil used is also small, namely a maximum of 5% of the mass of used cooking oil. It is hoped that mixing used cooking oil with lemon essential oil can replace biodiesel. Lemon essential oil is a bio-additive that can improve the quality of used cooking oil to approach the physical properties of biodiesel. With this new process, it is hoped that it can produce fuel that is cheap but of good quality. The aim of the research is to obtain a new fuel to replace biodiesel that is cheaper and more efficient, namely with cheap raw materials and fewer process stages so that it will reduce production costs. The research began with the activation of zeolite as an adsorbent for purifying used cooking oil with variables including zeolite mass of 400 grams, calcination temperature of 300⁰C, activation time of 2 hours and zeolite size > 80 mesh. The second stage of the research was purifying used cooking oil with zeolite using a variable volume of 3 liters of used cooking oil and a purification time of 1 hour. The third stage of the research was mixing purified used cooking oil with lemon essential oil with variable volume of essential oil (3, 4, 5, 6, 7% oil volume) and mixing temperature (30, 40, 50⁰C), mixing time 60 minutes, stirring speed 500 rpm and oil volume 150 mL. After the mixing time and the sample temperature reached room temperature, an analysis of the density, acid number, viscosity and FFA of used cooking oil with bio-additive lemon essential oil was carried out. The analysis results are compared with the biodiesel standard SNI 7182-2015 to see whether the product/sample approaches the physical properties of biodiesel

Study on line-scan profile for a trapezoid line under varying sample temperatures through Monte-Carlo simulation.

This study investigates the influence of the sample inherent temperature on the line-scan profile for a silicon trapezoid line with different sidewall angles by Monte-Carlo simulation. This study demonstrates that the profile varies with temperature, particularly focusing on the 'shoulder', which becomes more pronounced with larger sidewall angles. The contrast of the secondary electron profile increases at low primary electron energy but decreases at relatively high PE energy as the temperature rises. The trend of the backscattering electron profile is similar but less noticeable. The underlying mechanism is discussed in detail. This study has potential to provide valuable insights into thermometry in nanostructures using SEMs.

Analysis of an Al-Sn-Cu alloy by calibration-free laser-induced breakdown spectroscopy under varying sample temperature conditions

This study investigates the impact of sample temperature Ts on Laser-Induced Breakdown Spectroscopy (LIBS) emission characteristics and Calibration-Free LIBS (CF-LIBS) quantitative analysis in vacuum and air. Using an aluminum‑tin‑copper alloy, we analyze spectral lines within a 20 °C to 170 °C temperature range. Evaluation encompasses emission line intensities, plasma parameters, expansion imagery, and laser ablation crater morphologies. CF-LIBS analysis underlines that elevated Ts maintains quantitative accuracy even for minor elements with weak lines. In atmospheric conditions, tin segregation occurs, yet CF-LIBS remains robust. These results highlight CF-LIBS's potential for varied applications by mitigating Ts-induced effects.

Exploring electrical transport in thin film and bulk thermoelectric materials with an automated Seebeck coefficient and resistivity measurement platform

Accurate assessment of electrical properties, particularly the Seebeck coefficient and electrical resistivity, is critical in thermoelectric energy harvesting research, which involves converting thermal energy into electricity. This study presents an innovative automated system designed for the simultaneous measurement of the Seebeck coefficient and electrical resistivity as a function of temperature in both film and bulk samples. The system exhibits high precision across a wide range of electrical resistance, from milli Ohm (mΩ) to giga Ohm (GΩ). Furthermore, and in contrast with commercial systems, it provides excellent flexibility in accommodating samples with diverse lateral dimensions and thicknesses, ranging from a few millimetres to several centimetres. The measurement principle is based on analysing the current–voltage (I-V) characteristic of the samples. To ensure seamless monitoring and control of the measurement process, a user-friendly and adaptable Graphical User Interface (GUI) is integrated into the system, enhancing its overall user-friendliness and convenience.

Development of a 10 K automated sample exchange cryostat for SANS_CSNS

The Small-angle Neutron Spectrometer at China Spallation Neutron Source (SANS_CSNS) is a functional apparatus utilized for the examination of structures and inhomogeneities within the size range of 1 to 100 nm. The development of sample environments for in situ experiments at low temperatures at SANS_CSNS is urgent in order to address the increasing demands of users. The CSNS Sample Environment Group has successfully designed and constructed an automated sample exchange cryostat for SANS experiments, capable of operating in a temperature range of 10 ∼ 500 K. This cryostat has been specifically engineered to accommodate up to four samples simultaneously and exchange samples automatically in order to optimize the utilization of neutron beams by minimizing the downtime associated with manual sample handling. The results of simulation and temperature measurement proved that sample temperature could be accurately controlled from 10 K to 500 K through the incorporation of a 4 K GM cryocooler and a heater. Furthermore, neutron scattering studies conducted on SANS_CSNS proved that this cryostat exhibits commendable temperature control capabilities and minimal background interference. This automated sample exchange cryostat will be available to researchers of SANS_CSNS in the following user programs.

X-Ray Diffraction Measurements for Inconel 718 Alloy Elements Created by Incremental Methods

Abstract The work presented is the result of the implementation of diffraction measurements: phase composition and stresses resulting from additive manufacturing process of nickel superalloy Inconel 718 components print. With the help of diffraction methodologies, the key parameters from the point of view of the quality of prints and their strength were determined. The existence of individual phases in the material after printing was demonstrated, and the surface variation of the stress values was presented, showing its dependence on the geometry of the printed part – measurements were made at various points on the surface of samples with different geometries. In addition, the variation of the stress level was shown depending on the distance of the measurement point from the build platform on which the additive manufacturing process was carried out. Components were printed on the surface of a single build plate in order to study the effect of printing differently oriented samples with respect to the platform geometry, as well as the mutual effect of the temperature of samples printed first on the stress state of elements printed in subsequent steps of the procedure, and the effect of the temperature of elements printed later on the rate of temperature decrease, and consequently on the stress state, of elements printed first.

Infrared emission properties of VO2 films fabricated with different oxygen flow ratios

Infrared (IR) camouflage materials are widely used to realize thermal camouflage by adjusting the IR emissivity (ε) of the target object. However, ε modulation without an external energy supply is still a great challenge. Self-regulating VO2 films with different IR emission properties are investigated by adjusting the oxygen flow ratio (O2%) and film thickness. The ε of VO2 films changes before and after the phase transition, and the Δε (the difference of ε before and after the phase transition) of films is different under different O2%, and the maximum Δε can reach 0.49. In addition, the difference temperature (ΔTIR) between the actual temperature (TA: the surface temperature of a standard silicon wafer measured by IR camera, which represents the actual temperature of VO2 samples.) and the IR trapping temperature (TIR: the temperature of VO2 samples measured by IR camera.) is greater than 35 °C after the phase transition. With the range of 1.6 %–2.2 % O2, the IR emission transition temperature (Tε-MIT) and hysteretic width (ΔTε-MIT) increase with increasing O2%. The thickness of the VO2 film affects the IR emission characteristics. The VO2 film is suitable for thermal camouflage materials and for IR anticounterfeiting.

Silica Coating of Nickel–Iron Nanocomposite by Chemical Reduction Method

The study of magnetic nanostructures is interesting because of its applications. Some of them are the development of magnetic refrigerators, ferrofluids, drug delivery systems, fabrication of devices with giant magnetoresistance effects, and high-frequency transformers. The physical and chemical properties of metal changes due to silica coating. The interaction potential can be manipulated using surface coatings and also the particle shape can be controlled. Nanoparticles with a proper surface coating are of interest for several other applications in optoelectronic devices and in the biomedical field. Thus, developing a new synthetic route for these particles and investigating the stability of magnetic materials are of great importance. Silica coating improves the chemical stability and electrical resistivity of the material. In this study, Ni3Fe (core) nanoparticles were prepared and the silica shell for this core was synthesized. The as-prepared X-ray diffraction (XRD) patterns and 300∘C annealed sample of Ni3Fe/SiO2 shows a characteristic hump in the low angle range confirming the presence of amorphous cristobalite phase of SiO2. The size of the Ni3Fe cluster in the Ni3Fe/SiO2 composite was estimated to be 8[Formula: see text]nm and 9[Formula: see text]nm, respectively, for the as-prepared and annealed samples. Vibrating sample magnetometer (VSM) measurements show the Ni3Fe to silica ratio to be 59:41. A small decrease in the coercivity value, is probably due to morphological changes associated with the coating. Scanning electron microscope (SEM) studies of the as-prepared and annealed Ni3Fe/SiO2 powder particles are of flowerlike morphology and in agglomeration. The impedance spectra were found at room temperature for the as-prepared samples.

Development of a micro-infrared thermometry method for surface temperature distribution and variation of millimeter particle during high-temperature reaction

Temperature strongly affects the conversion efficiency, local reactivity, and particle stabilization of the reactions, particularly at high temperature. This study integrated infrared thermography with a high-temperature hot stage reactor to develop a methodology of continuous temperature measurement for a single particle reaction at high temperatures. The external optical transmission transmittance and temperature field core were corrected, and the relationship between the measured temperature (Tr) and true temperature (T0) was obtained by adjusting the sample emissivity. Sample temperature with known emissivity at elevated temperature was measured with 1% deviation. The instantaneous temperature measurement for the gasification process was carried out and the overall emissivities of coal particles were corrected. Temperature distribution and variation on the coal particle surface during the gasification process were further obtained and consistent with the previous research results. The proposed online temperature measurement method provides a new approach for gaining insights into particle reaction states.

Insight into compression-rebound behavior of lignocellulose-derived aerogel through finite element modeling based dynamic impact simulation

In this study, lignocellulose-derived aerogel (LA) with compression-rebound was synthesized from liquefied wood through sol-gel polymerization, aging and freeze-drying process. The results presented a gradual increase in the compressive strength, flexural strength, and maximum decomposition temperature of the LA sample with prolonged aging time from 3 to 10 h, demonstrating excellent elasticity and thermal stability. After more than 10 h, the bending strength began to decrease, indicating that the material’s rigidity was greater than its elastic toughness at this time. A nonlinear viscoelastic constitutive model based on the Ogden function and parallel rheological framework showed very high correlation with experimental measurement results, and also demonstrated admirable mechanical properties. These predictions can provide an effective approach for the application of LA in buffer packaging.

Rapid determination of germanium in lignite coal and coal-related solid byproducts by graphite furnace digestion inductively coupled plasma emission spectroscopy

This study developed a rapid and efficient graphite furnace digestion combined with inductively coupled plasma emission spectrometry (ICP-OES) method, enabling precise quantification of germanium (Ge) in coal and various coal-derived metallurgical byproducts across a broad concentration level (∼ppm-n%). The graphite furnace digestion conditions were examined intensively as a function of the acid amounts of HNO3 and HF (5–10 mL), temperature (80–180 °C), time (1–5 h), and acid drive methods (H3BO3 neutralization versus heating). Coal references including SARM 19, SARM 20, NIST SRM 1632e, and fly ash standard NIST SRM 2689 were tested. The optimum recovery of germanium was obtained when the HNO3 dosage, HF dosage, solid sample mass, temperature, and duration time were 10 mL, 5 mL, 0.1 g, 80 °C and 1 h. Agreement of 95.15–96.54 % between the measured and certified value was obtained under the optimum conditions. The spiked recovery was 103.23–103.54 %, indicating the matrix-analytes interactions were negligible. Boric acid neutralization reduced the recovery rates to 47.2–49.3 % and was not be appropriate for driving HF. The optimal spectral line for determining Ge is at a wavelength of 265.117 nm, at which the limit of detect and the limit of quantification were 0.46 μg L−1 and 1.53 μg L−1, respectively. The applicability of the method was validated by quantifying Ge in Ge-rich lignite, fly ashes (FA), and chlorinated distillation residue (CR) samples. The concentration of Ge in coals was 44.75–225.41 μg g−1, the content in FA was 0.68%–2.3 %, and the content in CR was 0.18 %, with the uncertainty of the method obtained being less than 0.5 %. X-ray fluorescence spectrometer (XRF) was used to verify the results. The difference between XRF data and ICP-OES data was less than 5 %, confirming the accuracy and reproductivity of the analytical method.

Enhancing solar furnace thermal stress testing using an adaptive model and nonlinear predictive control

Solar furnaces rely on renewable energy for thermal tests using concentrated solar direct irradiance. To address the complex dynamics and constraints of these systems, a novel control approach is introduced based on an adaptive model strategy. The proposed adaptive model representation with an Adaptive Practical Nonlinear Predictive Controller (A-PNMPC) strategy is employed in the solar furnace SF60 at Plataforma Solar de Almería (Spain), demonstrating enhanced model prediction that culminates in a finer control performance. A Recursive Least Squares solution for model adaptation adjusts the model dynamics to the actual behavior of the solar furnace. Then, the predictive control strategy uses the updated model to calculate optimal control actions that lead the sample temperature to the desired reference. Simulation studies demonstrated the superior performance of the A-PNMPC in temperature control and prediction compared to the constant parameter model PNMPC strategy. The proposed A-PNMPC was compared to the conventional PNMPC in simulations, showing up to a 5% improvement in control performance and an 80% in large model predictions. Additionally, the A-PNMPC was tested on the actual system for various temperature profiles, achieving a mean error of less than 10 °C in sample temperature ramp tracking

A failure risk assessment method for lithium-ion batteries based on big data of after-sales vehicles

Accurate prediction of battery failure has always been a challenge in the field of electric vehicles. In existing prediction methods, battery current, voltage and temperature of a single vehicle sample are often analyzed as the main characteristic parameters, however, the independent analysis of these parameters can hardly achieve the early warning of battery failure. This paper proposes a failure risk assessment method based on big data analysis, which can evaluate the failure risk level of the battery pack in advance. Specifically, the characteristic parameters strongly related to battery failure are extracted through the correlation analysis of after-sales data. Then, the synthetic minority oversampling technique is employed to expand the number of failure samples for model training. Finally, the vehicle risk coefficient prediction model is established by the random forest algorithm. According to the prediction results of field data of extensive vehicles, the model can successfully pick out the high-risk vehicles before battery failure, occupying roughly 7% of all vehicles, which is of great value for engineering application. In practical application, these vehicles with high-risk coefficient can be paid more attention by companies, so as to further ensure the driving safety of vehicle users.

Investigation of Ferromagnetic Nanoparticles’ Behavior in a Radio Frequency Electromagnetic Field for Medical Applications

This work raises the hypothesis that it is possible to use ferromagnetic carbon nanotubes filled with iron to hyperthermally destroy cancer cells in a radiofrequency electromagnetic field. This paper describes the synthesis process of iron-filled multi-walled carbon nanotubes (Fe-MWCNTs) and presents a study of their magnetic properties. Fe-MWCNTs were synthesized by catalytic chemical vapor deposition (CCVD). Appropriate functionalization properties of the nanoparticles for biomedical applications were used, and their magnetic properties were studied to determine the heat generation efficiency induced by exposure of the particles to an external electromagnetic field. The response of the samples was measured for 45 min of exposure. The results showed an increase in sample temperature that was proportional to concentration. The results of laboratory work were compared to the simulation using COMSOL software.

Spectroscopic assessment and quantitative analysis of the trace element composition of vegetable additives to meat products

In this scientific work, using the method of laser-induced breakdown spectroscopy (LIBS), the spectra of beef samples and impurities in meat products, namely, banana, pineapple, kiwi, bergamot, poria coconut, Chinese angelica, chicken blood vine, were measured by using developed experimental devices. The purpose of the research was to evaluate the qualitative characteristics of additives to meat semi-finished products for the potential formation of the desired properties of the products due to the analysis of the received spectrograms of trace elements of the samples when applying the LIBS method, quantitative analysis for processing the received information. The determined values of the electron temperature of the plasma, the electron density of the used raw material samples, and the assessment of the local heat balance were used as evaluation criteria. When processing the obtained data, the characteristics of the laser-induced plasma surface of the presented samples were analyzed; the electron temperature and electron density were determined, and a quantitative analysis of trace elements was carried out. LIBS technology allows rapid real-time monitoring and qualitative analysis of trace elements online and over long distances. During the research, it turned out that quantitative analysis requires further study and optimisation of experimental conditions, such as pre-treatment of samples. These conditions optimise defocusing, double laser pulse, and sample temperature, which increases the signal/noise ratio of all spectral lines. The combination of fluorescence spectroscopy and Raman technology enables higher detection sensitivity and better molecule control, creating a quantitative analysis method model that can reduce matrix effects and overcome the self-absorption effect. Among the difficulties of using LIBS technology, several elements can be noted online simultaneously, compared to Raman. The combination of spectroscopy and fluorescence spectroscopy can obtain more comprehensive information about the composition of materials, which can become a potential platform for monitoring trace elements in food products.

Determination of the temperature of an object irradiated by microwaves using spectral pyrometry

Recently, due to increasing environmental requirements, microwave carbonization method has been widely investigated for the production of activated carbon from biomass waste. Microwave carbonization is a more energy efficient and environmentally friendly method compared to traditional carbonization in thermal furnaces, but to date there are still a number of questions about the reproducibility and temperature stability of this process. During microwave irradiation, the temperature of biomass samples changes continuously and complex physical and chemical processes occur in them. For deeper study of these processes and determination of optimal modes of microwave treatment it is necessary to know the temperature dynamics of biomass samples. For this purpose, the method of spectral pyrometry based on the allocation of sections of the spectra of thermal radiation of samples coinciding with the Planck spectrum was used. In the specified spectral sections these samples are gray emitters. The method is effective for an unknown emission coefficient, continuously varying with changes in the microstructure, chemical composition and phase state of the sample. The sample irradiated by microwaves was a sample of orthophosphoric acid-treated cotton down weighing 1 g. The microwave source was a magnetron-type generator with a maximum output power of 600 W and an operating frequency of 2450 MHz. Thermal spectra of the irradiated sample were recorded by small-size spectrometers of visible (350–760 nm) and near-infrared (650–1050 nm) ranges. The time of irradiation of samples by microwaves was varied in the range of 60–180 s. To process the obtained spectra, the program “Spectral Pyrometry” was used, which reads the recorded spectrum, processes it, plots it in the necessary coordinates and calculates the temperature. Analysis of the obtained results revealed different types of thermal radiation spectra of the irradiated sample - spectra similar to spectra of a completely black body, spectra with different temperature zones of the sample, spectra with atomic lines and molecular bands. The results obtained are useful for the study of microwave influence on various objects, research of processes occurring during carbonization of biomass, as well as for the development of more effective modes of production of activated carbons by microwave method.