One-Dimensional Systemic Modeling of Thermal Sensors Based on Miniature Bead-Type Thermistors

Accurate measurements of thermal properties is a major concern, for both scientists and the industry. The complexity and diversity of current and future demands (biomedical applications, HVAC, smart buildings, climate change adapted cities, etc.) require making the thermal characterization methods used in laboratory more accessible and portable, by miniaturizing, automating, and connecting them. Designing new materials with innovative thermal properties or studying the thermal properties of biological tissues often require the use of miniaturized and non-invasive sensors, capable of accurately measuring the thermal properties of small quantities of materials. In this context, miniature electro-thermal resistive sensors are particularly well suited, in both material science and biomedical instrumentation, both in vitro and in vivo. This paper presents a one-dimensional (1D) electro-thermal systemic modeling of miniature thermistor bead-type sensors. A Godunov-SPICE discretization scheme is introduced, which allows for very efficient modeling of the entire system (control and signal processing circuits, sensors, and materials to be characterized) in a single workspace. The present modeling is applied to the thermal characterization of different biocompatible liquids (glycerol, water, and glycerol–water mixtures) using a miniature bead-type thermistor. The numerical results are in very good agreement with the experimental ones, demonstrating the relevance of the present modeling. A new quasi-absolute thermal characterization method is then reported and discussed. The multi-physics modeling described in this paper could in the future greatly contribute to the development of new portable instrumental approaches.

Conversion of Multicyclic Hydrocarbons to Mono-Aromatic Hydrocarbons Over CoMo/Zeolite Socony Mobil-5 Catalysts

This study focuses on analyzing the effects of the SiO2/Al2O3 ratio of a support on the physico-chemical properties of bead-type CoMo/HZSM-5 catalysts and on the catalytic performance during the hydrocracking reaction of PFO. CoMo/HZSM-5 catalysts were prepared by an incipient wetness method. Subsequently, binder-added catalysts were molded into the bead type catalysts. The N2 adsorption-dersorption results clearly indicate that the nanoporous structure was well developed in the bead-type CoMo/HZSM-5 catalyst. The CoMo/HZSM-5(30) catalyst not only possessed the highest number of acid sites but also showed the highest ratio of strong acid to weak acid sites. Moreover, the Lewis acid/Brönsted acid site ratio is highest with the CoMo/HZSM-5(30) catalysts. A hydrocracking reaction of PFO over the bead-type CoMo/HZSM-5 catalysts was conducted at 400 °C and under 40 atm in a fixed-bed reactor. The bead-type CoMo/HZSM-5(30) catalyst showed the highest BTXE yield with a sum of BTXE outcome of 43.0% in the catalytic cracking reaction of PFO, which is attributed to the synergistic combination of suitable acidity and hierarchical porosity.

An evaluation of the suitability of fluorescent fabrics and retroreflective materials for road traffic warning clothing in compliance with international standards

The purpose of this study is to compare and analyze physical properties of different fluorescent fabrics and retroreflective materials to determine their compliance to international standard for high-visibility warning clothing. Four fluorescent fabrics were selected for the study: a PET 71%/Cotton 23%/PU 6% fabric used in public road cleaner uniforms in Korea (S1), an ISO-compliant Japan-made PET 65%/Cotton 35% + conductive fabric (S2), and a randomly selected Korean-made PET 100% fabric for adults (S3) and children (S4). Selected samples were evaluated on their seven criteria in ISO 20471. Subsequently, luminance and retroreflective properties of four retroreflective materials were compared: a 3M (USA) plain sample (R1), a rectangular-patterned sample made by ‘R’ company (Korea) (R2), a plain sample also by ‘R’ (R3), and a random plain sample from a marketplace in Korea (R4). As a result, S1 was the most similar to ISO-compliant S2 and moisture regain could be improved by adjusting the cotton ratio or surface finishing. However, S3 and S4 seemed less suitable. Second, two bead type (R1, R4) and two prism type (R2, R3) retroreflective materials showed luminance in the order of R4 > R2 ≥ R1 > R3. General retroreflective properties and post-5-condition retroreflective properties of all four samples were ISO-compliant, and the retroreflective property at observation angle of 12′ and incidence angle of 5° of R2, R3, and R4 against R1 ranged between 81.4% and 158.4%. Despite the variance, all four samples were ISO-compliant and suggest that R2, R3, and R4 are possible materials for export.

Bead-type polystyrene/nano-CaCO3(PS/nCaCO3) composite: a high-performance adsorbent for the removal of interleukin-6

A novel nano-CaCO3(nCaCO3) particle composite-derived polystyrene (PS) resin can show high adsorption capacity for interleukin-6 from human plasma.