Temperature Stability Research Articles

Stabilization of Environmental Conditions when Liquid Density Measuring by Hydrostatic Weighting

When assessing the quality of products, especially oil and oil products, the density value is widely used along with other parameters. Density data are fundamental for studying the properties of liquids, their identification and determining the degree of purity. They are also necessary for indirectly assessing with a certain degree of accuracy some other properties of the liquid, such as specific gravity, thermal expansion or contraction, the mass of a known volume of liquid, etc. In turn, the accuracy of the density determination determines the correctness of the decision made in the technological quality control of the manufactured products. Determining the density of a liquid with high accuracy requires maintaining stable temperature conditions during the measurement process. The purpose of the work was to establish the effect of temperature stability on the reproduction and transmission of the unit of liquid density. To stabilize the temperature, a technical solution is proposed, implemented in the form of a climatic chamber, inside which reference equipment is placed. A study of the temperature conditions in the process chamber was carried out. It was found that due to the technical solutions used, the influence of environmental conditions on the change in the temperature of the liquid under study is a negligible value.

Design and Performance Analysis of Meteorological Temperature Sensor Calibration Device Using Gas Cavities

In order to solve the problem of a meteorology temperature sensor not being able to touch a liquid, an open gas cavity structure immersed in the liquid was designed. According to the characteristics that the temperature sensing position of the meteorological temperature sensor is in the bottom area of the gas cavity, a simulation and experimental study of the bottom temperature field of φ50 mm cylindrical and φ(50-35-25) mm stepped column gas cavities were carried out. The experimental results at (−30~30) °C show that the gas stability of the gas cavities was better than that of the liquid constant temperature bath, and the performance of the cylindrical gas cavity was the best. The gas temperature stability of the stepped column gas cavity and the liquid constant temperature bath follow a strong trend. The maximum stability of the cylindrical gas cavity is 0.0054 °C, and the maximum stability of the stepped column gas cavity is 0.0080 °C. The results also show that the maximum uniformity of the stepped gas cavity is 0.0077 °C, and the maximum uniformity of the cylindrical gas cavity is 0.0528 °C. The uncertainty introduced in the measurement process was evaluated to ensure the confidence of the experimental data. The maximum value of the extended uncertainty was U = 0.0027 °C (k = 2). Compared with the solid-state constant temperature bath calibration method, the temperature sensor of different shapes can be directly placed into the gas cavity without the need for the meteorological temperature sensor to be closely attached to the wall of the gas cavity, and a sealing plug is used to seal the cavity mouth. The operation is very convenient, rapid turnover of the calibration of the meteorological temperature sensor can be achieved, and the work efficiency can be improved. Superior stability and uniformity can be obtained compared to gas constant temperature cavities. This study provides a valuable reference for the structural design of large-volume gas cavities and provides support and guarantee for global climate change monitoring.

Enhanced piezoelectricity and temperature stability in La-doped PIN-PMN-PT transparent ceramics by composition regulation

Transparent ferroelectric ceramics are popular due to their ability to couple optical and electrical properties. However, simultaneously achieving high electrical and optical performance in ceramics remains a formidable challenge. By using the two-step sintering process combined with a rare earth doping strategy, xLa-24PIN-42PMN-34PT transparent piezoelectric ceramics were prepared, achieving the coexistence of the highest known d33 (>1000 pC/N), excellent transmittance (T = 66.2% at 1600 nm), and the piezoelectric properties decrease by only 26.8% when approaching TC. PFM and in situ XRD results indicate that the parallel stripe-like and watermark-like coexisting ferroelectric domain structures, which are induced by La3+ doping, generate large piezoelectric responses. Light scattering loss is reduced by the small size of the ferroelectric domain structure. Excellent thermal stability is ensured by the tetragonal-dominated morphotropic phase structure. This work provides a valuable idea for the subsequent preparation of transparent ferroelectric ceramics with high performance.

Technique and protocol for bedside neuroendoscopic lavage for post-hemorrhagic hydrocephalus: technical note.

Neuroendoscopic lavage (NEL) is a time-limited neurosurgical intervention that removes intraventricular blood in post-hemorrhagic hydrocephalus (PHH). Preterm neonates are medically complex and fragile, often precluding neurosurgical procedures due to concerns such as extubation risk and body temperature instability during even routine clinical care. In addition, transportation to the operating room can be difficult and risky. Given these factors, our institution developed and implemented a bedside technique to facilitate safe and timely NEL in the neonatal intensive care unit for the treatment of PHH.

Bioinspired Fern-like Fe2O3 Functionalized with Pd/PdO Nanoparticles for High-Performance Acetone Sensing.

The accurate monitoring and detection of acetone vapor are essential for environmental and human safety. Consequently, fern-like Fe2O3 with hierarchical vein-like structures is synthesized via a concise hydrothermal method. Compared with pure fern-like Fe2O3, fern-like Pd/PdO-Fe2O3 shows the best acetone-sensing characteristics, in terms of lower operating temperature (180 °C), better selectivity and excellent long-term stability. More importantly, the response value of the Pd/PdO-Fe2O3 sensor to 100 ppm acetone reaches as high as 73, which is 55% higher than that of pristine fern-like Fe2O3. This enhanced sensing performance can be ascribed to the synergistic effect between Pd/PdO and fern-like Fe2O3. On the one hand, Pd/PdO nanoparticles show favorable catalytic activity toward ionized oxygen molecules; meanwhile, the formation of the heterojunction between PdO and fern-like Fe2O3 plays an important role. On the other hand, the hierarchical nature of fern-like Fe2O3 promotes efficient gas diffusion throughout the structure. Based on its advantages, fern-like Pd/PdO-Fe2O3 becomes a satisfactory candidate for acetone gas sensors.

Enhanced electrical reliability of Zr‐doped BaTiO3 nanoceramics: First‐principle calculations and experimental studies

AbstractWith the miniaturization of multilayer ceramic capacitors (MLCCs) and the increase of electric field on single‐layer dielectrics, it is essential for the development of nanograin high‐reliability dielectric materials. In this work, Zr‐doped BaTiO3‐based ceramics with an average grain size of 130–150 nm were prepared by a chemical coating method. The effects and intrinsic mechanisms of Zr concentration on microstructure, dielectric properties, and reliability were systematically investigated by theoretical calculations and experiments. Zr additives lower the migration barrier of the dopants, which consequently contributes to the formation of thick shell layers in the core‐shell structure and grain growth, affecting the temperature stability and DC bias characteristics of the dielectric constant. Owing to the large change rate of the Zr–O bond length, the introduction of Zr increases the migration barrier of oxygen vacancies. However, the decrease in the effective doping concentration of the shell part and the reduction in the number of grain boundaries of ceramics with high Zr content have a weakening effect on the inhibition of oxygen vacancy migration. An appropriate amount of Zr doping can adjust the dielectric properties and improve the reliability of BaTiO3‐based ceramics. This study provides a theoretical reference for the design of high‐quality MLCCs.

Ceasing or gradually reducing incubator humidity after 7days for extremely preterm infants: a randomised clinical trial.

Ceasing or gradually reducing incubator humidification after day 7 of life had no effect on the number of episodes of hypothermia or hyperthermia in this cohort of extremely preterm infants (EPTI). There was also no effect on the number of episodes of hyponatraemia or hypernatraemia. ANZCTR.org.au (Australia New Zealand Clinical Trials Registry). ACTRN 1261 9000 266167 Registered 21/2/2019. • Incubator humidification is a widely accepted and routine practice in the management of EPTI as it influences transepidermal water loss (TEWL) and supports thermoregulation. However, weaning practices remain varied and inconsistent across the globe. • There remains a paucity of data to inform specific evidenced-based humidification practices. • Ceasing or gradually reducing incubator humidification after 7days had no effect on temperature stability, serum sodium levels, or frequency of skin injury in this cohort of EPTI between day 8 and day 14. • There is no apparent benefit in prolonging incubator humidity beyond day 7 of life in these EPTI.

Ultrahigh piezoelectric properties and high transparency relaxor ferroelectric single crystals obtained by the combination of rare-earth doping and AC-poling

High-performance relaxor ferroelectric single crystals, such as Pb(Mg1/3Nb2/3)O3–PbTiO3 (PMN–PT), play a crucial role in the applications of medical ultrasonic imaging due to their high piezoelectric properties. In this study, we successfully grew a 2-in. Eu-doped PMN–PT single crystal whose composition variation and electrical properties were systematically investigated. It was found that the PT content of the crystal boule increased gradually along the growth direction, while the change of Eu3+ content was opposite. The property results show that Eu-doped PMN–PT single crystals exhibit a remarkable piezoelectric coefficient of 3300 pC N−1 at DC-poling while maintaining the rhombohedral phase to a tetragonal phase transition temperature (TRT) at 88 °C and the coercive field (EC) at 2.7 kV cm−1, higher to the undoped single crystals. Through the study of the local structure of Eu-PMN–PT, it illustrated that the introduction of Eu3+ increased the standard deviation of an A sublattice from 3.0% to 4.8%. The dopant simultaneously enhanced a tetragonal phase ratio and local structural heterogeneity, resulting in improved piezoelectric properties and temperature stability of the crystal. We further treated the doped crystals with AC-poling to obtain ultrahigh piezoelectric performance (d33 > 4000 pC N−1) and high transparency. This work provides a new approach to achieve a relaxor ferroelectric single crystal with high performance and transparency with good temperature stability, which could be the material of choice for optoelectronic devices in the future.

Si APD-Based High Speed Infrared Radiation Thermometry for Analysing the Temperature Instability of a Combustion Chamber.

This study introduces a novel approach to analysing the combustion process using a high-speed, non-contact, optical fibre-coupled Si avalanche photodiode (APD)-based infrared radiation thermometer (IRT). The Si APD-IRT, combined with an optimised field-programmable gate array (FPGA)-based digital design, achieves a response time of 1 µs, faster than commercially available instruments. Our instrument captures the entire ignition and reignition cycle of a Jet A kerosene droplet with high temporal precision within a combustion chamber, a feat impossible with traditional thermocouples. The FPGA module was validated with a 1 µs data acquisition time, using a 40 MHz onboard clock, achieving throughput of 0.64 Gbps with efficiencies of 0.062 Mbps/slice in lookup tables (LUTs), confirming a low-area design compared to conventional FPGAs. The IRT achieves a root mean square (RMS) noise specification of 0.5 °C at a 1 µs acquisition time and a target temperature of approximately 1000 °C. A measurement uncertainty of within ±0.25% °C + 2 °C confirms that it lies within the bounds of commercial instrumentations. Our instrument was demonstrated to capture transient temperature fluctuations during combustion and characterises Jet A kerosene fuel droplets, laying the foundation for understanding sustainable aviation fuels (SAFs) and their role in transitioning from aviation fossil fuels, enabling effective research and development.

In situ crosslinked gel polymer electrolytes for Li-ion capacitors using sacrificial salt pre-lithiation, enabling high-temperature operation

In this work the effect of encapsulating a standard liquid electrolyte (1 M LiFSI in EC:DMC) into a polymer matrix for Li-ion capacitors pre-lithiated using Li2C4O4 sacrificial salt is presented. The polymer precursor is added in liquid state, which facilitates the integration in already existing cell manufacturing lines and is polymerized in situ at 60 °C after cell assembly. The application of a gel polymer electrolyte (GPE) is demonstrated to have many benefits such as lowered risk of electrolyte leakage, reduced flammability, improved high-temperature stability and high-temperature performance. The introduction of the polymer component is suggested to improve the stability of the solid electrolyte interface (SEI), enabling capacity retention of >95 % after 1200 h floating at 60 °C first (600 h) and 70 °C after (600 h). The increased performance at higher temperatures over room temperature is explained by an increased capacity of the hard carbon (HC) negative electrode together with an improved ionic conductivity of the GPE. Further increasing the operational temperature window of the LIC to 80 °C enables additional 600 h floating, demonstrating the feasibility of the GPE concept to improve high temperature stability and performance of commercial Li-ion capacitors, importantly, without sacrificing room temperature operation.

Temperature dependence of the coupling loss between polymer optical waveguides and SMF for co-packaging.

We theoretically calculate the coupling loss between single-mode fibers (SMFs) and polymer optical waveguides with different refractive index profiles. Temperature resistance is one of the concerns when integrating polymer optical waveguides near the electronics and photonics chips where they are highly likely to dissipate heat. Hence, the calculation focuses on the core size variations due to changes in operating temperature. The calculated results show that the refractive index variation with respect to temperature has a greater impact on coupling loss compared to the temperature-dependent core size variation. Then, polymer optical waveguides are experimentally fabricated and characterized. The temperature dependence of the output light intensity distribution from the fabricated waveguides is observed, as it is estimated by the theoretical calculation. In addition, it is also found that graded-index cores in polymer waveguides demonstrate slightly higher temperature stability in connection with SMF than their step-index counterparts. Such a low coupling loss with SMF could be maintained even in an environment at 100 °C, making polymer optical waveguides promising for the application of co-packaged optics.

Improving piezoelectric strain, temperature stability and strain symmetry on KNN-based ceramics sintered in reducing atmosphere via designing internal bias field

Improving piezoelectric strain, temperature stability and strain symmetry on KNN-based ceramics sintered in reducing atmosphere via designing internal bias field

Encapsulation of Antarctic krill peptide by polysaccharide-based nanoparticles: Preparation, characterization, evaluation of stability and hypoglycemic activity

The aim of this study was to construct a chitosan quaternary ammonium salt (HTCC)/sodium alginate (SA) nanoparticle delivery system for the encapsulation of Antarctic krill peptide (AKP), with the goal of enhancing its stability and post-digestive hypoglycemic activity. Additionally, the effect of the content and encapsulation sequence of HTCC/SA on the structure and properties of AKP-loaded nanoparticles (AKP-loaded NPs) was investigated. As the content of the outermost wall material (HTCC) increased, the particle size of nanoparticles initially increased and then decreased. Concurrently, the zeta potential showed a trend of increase, ranging from -38.77 to 46.07 mV. When SA was used as the outermost wall material, the nanoparticles exhibited a smaller particle size (240.1 nm) and better dispersibility. Electrostatic interaction and hydrogen bonding were the major forces involved in the formation of AKP-loaded NPs. X-ray diffraction revealed that AKP was successfully encapsulated in an amorphous state. Scanning electron microscopy showed that AKP-loaded NPs had an elliptical or blocky appearance. Moreover, AKP-loaded NPs demonstrated good storage and temperature stability, while nanoparticles with HTCC in the outermost layer (HTCC:SA=2:1) showed good pH and ionic stability. During simulated digestion, AKP-loaded NPs inhibited the release of AKP in gastric fluid. Consequently, the hypoglycemic activity of digested AKP-loaded NPs was remarkably higher than unencapsulated AKP. Notably, the nanoparticles with HTCC in the outermost layer provided superior hypoglycemic activity. In summary, the polysaccharide-based delivery system exhibited great potential to improve the stability and post-digestive hypoglycemic activity of AKP, broadening its applications in the food and pharmaceutical industries.

Performance characterization and combination design optimization of fast-melting SBS/CR modified asphalt

To broaden the application prospects of fast-melting styrene-butadiene-styrene modifiers (F-SBS) and meet diverse requirements, this study utilizes crumb rubber (CR) as a partial substitute for F-SBS to prepare fast-melting SBS/CR modified asphalt (F-SCMA). Firstly, rheological tests were conducted on fast-melting SBS modified asphalt (F-SBSMA) with varying dosages of F-SBS (3.0%, 3.5%, and 4.0%). Subsequently, F-SBS was added to the neat asphalt in dosages of 3.0%, 2.5%, 2.0%, 1.5%, and 1.0%. CR was then incorporated into the F-SCMA in corresponding dosages (2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, and 10%) to form F-SCMA with different ratios of F-SBS and CR. The dosage of F-SCMA was further determined using performance grade (PG), Brookfield viscosity, linear amplitude sweep (LAS), softening point difference, and multiple stress creep and recovery (MSCR) tests. Finally, the microscopic mechanisms of F-SCMA were characterized using Fourier transform infrared spectroscopy (FTIR) and fluorescence microscopy (FM) tests. The results indicated that F-SBS significantly enhanced the rheological properties of neat asphalt. The modified asphalt containing 3.5% F-SBS exhibited a PG of 76-28, which represents the most significant modification effect among the various dosages of F-SBSMA. In comparison, the F-SCMA with 2.5% F-SBS and 6% CR demonstrated higher high- and low-temperature continuous PG, better temperature stability, improved elasticity, and enhanced fatigue resistance than 3.5% F-SBSMA. F-SCMA containing 3% F-SBS and 4% CR, as well as 1% F-SBS and 8% CR, exhibited superior high- and low-temperature properties, respectively. Furthermore, FTIR and FM tests revealed that F-SBS and CR were effectively incorporated into the asphalt through a physical mixing process, indicating compatibility between the two modifiers and the neat asphalt. This study establishes a theoretical framework for assessing the comprehensive performance of F-SCMA, expands the application prospects of F-SBS, and provides design concepts for the application of F-SCMA in environments with different requirements.

Determination of Toxicity Using the Activated Sludge Respiration Inhibition Test and Identification of Sensitive Boundary Conditions

Toxic pollutants in wastewater can negatively affect biological processes in WWTPs, leading to operational failures and environmental harm if undetected. This study refines the ISO 8192 method for enhanced toxicity detection in WWTPs, meeting the critical need for rapid and reliable monitoring. The novelty of this study lies in the optimization and identification of sensitive boundary conditions (e.g., temperature stability, consistent mixing speed, and immediate aeration), which are crucial for ensuring the accuracy and reproducibility of the method. The optimization results indicate that sludge prepared via settling yields EC50 values comparable with those achieved with sludge prepared via centrifugation. For total oxygen consumption inhibition, the EC50 values were 9.22 ± 0.21 mg/L (centrifuged) and 9.42 ± 0.16 mg/L (settled), with nitrification inhibition values of 1.92 ± 1.24 mg/L and 2.17 ± 1.5 mg/L, respectively. The verification results obtained using samples from the Graz and Trofaiach WWTPs demonstrate EC50 values of 12.38 ± 2.05 mg/L and 12.25 ± 0.62 mg/L (total oxygen consumption inhibition), 23.31 ± 4.62 mg/L and 19.32 ± 0.29 mg/L (heterotrophic inhibition), and 1.54 ± 0.94 mg/L and 3.48 ± 2.65 mg/L (nitrification inhibition), which are all within the accepted ranges of validity of the method. The optimized ISO 8192 method provides a robust and efficient tool for WWTPs, enabling rapid responses to toxicity events and supporting regulatory compliance. These refinements enhance the practicality and reliability of the method.

Parameters of Performance: A Deep Dive into Liquid-to-Air CDU Assessment

The rapid growth in data center workloads and the increasing complexity of modern applications have led to significant contradictions between computational performance and thermal management. Traditional air-cooling systems, while widely adopted, are reaching their limits in handling the rising thermal footprints and higher rack power densities of next-generation servers, often resulting in thermal throttling and decreased efficiency, emphasizing the need for more efficient cooling solutions. Direct-to-chip liquid cooling with cold plates has emerged as a promising solution, providing efficient heat dissipation for high-performance servers. However, challenges remain, such as ensuring system stability under varying thermal loads and optimizing integration with existing infrastructure. This comprehensive study digs into the area of data center liquid cooling, providing a novel, comprehensive experimental investigation of the critical steps and tests necessary for commissioning coolant distribution units (CDUs) in direct-to-chip liquid-cooled data centers. It carefully investigates the hydraulic, thermal, and energy aspects, establishing the groundwork for Liquid-to-Air (L2A) CDU data centers. A CDU’s performance was evaluated under different conditions. First, the CDU’s maximum cooling capacity was evaluated and found to be as high as 89.9 kW at an approach temperature difference (ATD) of 18.3 °C with a 0.83 heat exchanger effectiveness. Then, to assess the cooling performance and stability of the CDU, a low-power test and a transient thermohydraulic test were conducted. The results showed instability in the supply fluid temperature (SFT) caused by the oscillation in fan speed at low thermal loads. Despite this, heat removal rates remained constant across varying supply air temperatures (SATs), and a partial power usage effectiveness (PPUE) of 1.042 was achieved at 100% heat load (86 kW) under different SATs. This research sets a foundation for improving L2A CDU performance and offers practical insights for overcoming current cooling limitations in data centers.

Recovery of Quasi-Permanent Bias Temperature Instability in SiC MOSFETs and Its Physical Mechanism

Recovery of Quasi-Permanent Bias Temperature Instability in SiC MOSFETs and Its Physical Mechanism

Gate Length Dependence of Bias Temperature Instabilities up to 400 °C in 4H-SiC CMOS Devices

Gate Length Dependence of Bias Temperature Instabilities up to 400 °C in 4H-SiC CMOS Devices

Enhanced dielectric and piezoelectric temperature stability of (Ba0.85Ca0.15)(Zr0.1Ti0.9)O3 porous ceramics for energy harvesting

Enhanced dielectric and piezoelectric temperature stability of (Ba0.85Ca0.15)(Zr0.1Ti0.9)O3 porous ceramics for energy harvesting

Superior temperature stability and outstanding fatigue resistance in Na0.5Bi0.5TiO3-BaTiO3 based Pb-free dielectric energy storage ceramics via a composite approach involving linear dielectric modification

Dielectric ceramic capacitors are candidates for a new generation of pulsed power supplies, owing to their superior power density. Nevertheless, low energy storage density and poor working reliability (such as temperature stability and fatigue resistance) have hindered the wide application of dielectric ceramic capacitors. To this end, a new composition-based optimization and process improvement strategy is proposed to build relaxor ferroelectric ceramic systems with weak pinning effect domain structure, which not only ensure the performance of ceramic energy storage, but also take into account the reliability of actual work. In this study, lead-free ceramics with formula 0.75(0.94Na0.5Bi0.5TiO3-0.06BaTiO3)-0.25CaTiO3, prepared by viscous polymer processing, exhibit an extremely high energy storage density, reaching up to 6.62 J/cm3 under a field strength of 520 kV/cm. In addition, after 106 cycles at 200 kV/cm, the efficiency remains at 85.9 %, with the sample's energy storage density exhibits a change rate of only 4 %. Additionally, under 300 kV/cm and across a temperature range of 30–150 °C, the change rate is a mere 1.7 %, which indicates that it has exhibited great fatigue resistance and excellent temperature stability. Therefore, this developed ceramic possesses great potential for practical industrial application as dielectric capacitors.