Stepwise emergence of CO gas sensing response and selectivity on SnO using C supports and PtO decoration.

Room temperature gas sensing is crucial for practical devices used in indoor environments. Among various materials, metal oxides are commonly used for gas sensing, but their strong insulating properties limit their effectiveness at room temperature. To address this issue, many studies have explored diverse methods such as nanoparticle decoration or conductive support, etc.

Physical interpretation of entropy, Boltzmann constant, and temperature.

Through the previously reported the quantum-identity, the light-model, and the T S energy, the implied meaning of temperature and entropy, respectively, which it was difficult to intuitively recognize, was clearly defined. In order to minimize possible errors at this time, the interrelationship of the SI base unit, which is the smallest unit, and the T S unit integration was used. In the process of converting to Planck units, each unit (criterion) for entropy and temperature was calculated, and their physical and chemical meanings were compared and reinterpreted.

Minimizing Area-Specific Resistance of Electrochemical Hydrogen Compressor under Various Operating Conditions Using Unsteady 3D Single-Channel Model.

Extensive research has been conducted over the past few decades on carbon-free hydrogen energy. Hydrogen, being an abundant energy source, requires high-pressure compression for storage and transportation due to its low volumetric density. Mechanical and electrochemical compression are two common methods used to compress hydrogen under high pressure.

Chemical and Biological Profiles of in Two Different Species, Their Hybrid, and Gamma-Irradiated Mutant Lines of the Hybrid Based on LC-QToF MS and Cytotoxicity Analysis.

The species (Orchidaceae) has been cultivated as an ornamental plant as well as used in traditional medicines. In this study, the chemical profiles of Dendrobii Herba, used as herbal medicine, in two different species, their hybrid, and the gamma-irradiated mutant lines of the hybrid, were systematically investigated via ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-QToF MS). Among the numerous peaks detected, 17 peaks were unambiguously identified.

Experimental study of superheating of tin powders.

An unstable energy-unbalanced state such as superheating or supercooling is often unexpectedly observed because a factor of energy depends not only on the temperature but is a product of temperature (T) and entropy (S). Thus, at the same temperature, if the entropy is different, the total energy of the system can be different. In such cases, the temperature-change-rate cannot match the entropy-change-rate, which results in a hysteresis curve for the temperature/entropy relationship.

Interface treatment using amorphous-carbon and its applications.

Breakthrough process technologies have been introduced that can increase the chemical sensitivity of an interface at which reactions occur without significantly altering the physico-chemical properties of the material. Such an interfacial treatment method is based on amorphous-carbon as a base so that fluids can be deposited, and the desired thickness and quality of the deposition can be ensured irrespective of the interface state of the material. In addition, side effects such as diffusion and decreasing strength at the interface can be avoided.

Synthesis of Au/SnO nanostructures allowing process variable control.

Theoretical advances in science are inherently time-consuming to realise in engineering, since their practical application is hindered by the inability to follow the theoretical essence. Herein, we propose a new method to freely control the time, cost, and process variables in the fabrication of a hybrid featuring Au nanoparticles on a pre-formed SnO nanostructure. The above advantages, which were divided into six categories, are proven to be superior to those achieved elsewhere, and the obtained results are found to be applicable to the synthesis and functionalisation of other nanostructures.

Fast Semiconductor-Metal Bidirectional Transition by Flame Chemical Vapor Deposition.

A simple yet powerful flame chemical vapor deposition technique is proposed that allows free control of the surface morphology, microstructure, and composition of existing materials with regard to various functionalities within a short process time (in seconds) at room temperature and atmospheric pressure as per the requirement. Since the heat energy is directly transferred to the material surface, the redox periodically converges to the energy dynamic equilibrium depending on the energy injection time; therefore, bidirectional transition between the semiconductor/metal is optionally available. To demonstrate this, a variety of Sn-based particles were created on preformed SnO nanowires, and this has been interpreted as a new mechanism for the response and response times of gas-sensing, which are representative indicators of the most surface-sensitive applications and show one-to-one correspondence between theoretical and experimental results.

Incorporation of Pt Nanoparticles on the Surface of TeO₂-Branched Porous Si Nanowire Structures for Enhanced Room-Temperature Gas Sensing.

A new gas sensor working in room temperature, which is compatible with silicon fabrication technology is presented. Porous silicon nanowires (NWs) were synthesized by metal-assisted chemical etching method and then TeO₂ NWs branches were attached to their stem by thermal evaporation of Te powders in the presence of air. Afterwards TeO₂ branched porous Si NWs were functionalized by Pt via sputtering followed by low temperature thermal annealing.

Pore Characteristics of Lotus-Type Porous Cu-Fe and Cu-Cr Alloys Fabricated by Unidirectional Solidification.

Lotus-type porous Cu-Fe and Cu-Cr with long cylindrical pores was fabricated by centrifugal casting under hydrogen atmosphere and the effect of alloying elements on pore characteristics of lotus-type porous Cu was investigated. For the lotus type porous Cu-Fe alloy, the porosity slightly decreased and the average pore diameter slightly increased with increasing Fe content. For the lotus-type porous Cu-Cr alloy, the porosity sharply decreased and the average pore diameter drastically increased with an increase in the Cr content.

Effect of Zn on Pore Characteristics in Lotus-Type Porous Cu.

The effect of Zn on pore characteristics in lotus-type porous Cu alloy was investigated. The lotustype porous Cu-Zn alloys were fabricated with Zn content from 0.01 to 0.

Design and synthesis of amorphous SiOx structures generated by Sn quantum dots: growth mechanism and luminescent origin.

SiOx structures with different diameters of a few hundreds of nanometers and/or a few micrometers are prepared using applied thermal evaporation. Subsequently, Sn quantum dot-based SiOx architectures are synthesized via the continuous steps of the carbothermal reduction of SnO2, substitution of Sn(4+) for In(3+), thermal oxidation of Si, Sn sublimation, interfacial reaction, and diffusion reaction consistent with corresponding phase equilibriums. Several crystalline and spherical-shaped Sn quantum dots with diameters between 2 and 7 nm are observed in the amorphous SiOx structures.

Growth Mechanism and Luminescent Properties of Amorphous SiOx Structures via Phase Equilibrium in Binary System.

Balloon whisk-like and flower-like SiOx tubes with well-dispersed Sn and joining countless SiOx loops together induce intense luminescence characteristics in substrate materials. Our synthetic technique called "direct substrate growth" is based on pre-contamination of the surroundings without the intended catalyst and source powders. The kind of supporting material and pressure of the inlet gases determine a series of differently functionalized tube loops, i.

Synergistic Effects of a Combination of Cr2O3-Functionalization and UV-Irradiation Techniques on the Ethanol Gas Sensing Performance of ZnO Nanorod Gas Sensors.

There have been very few studies on the effects of combining two or more techniques on the sensing performance of nanostructured sensors. Cr2O3-functionalized ZnO nanorods were synthesized using carbothermal synthesis involving the thermal evaporation of a mixture of ZnO and graphite powders followed by a solvothermal process for Cr2O3-functionalization. The ethanol gas-sensing properties of multinetworked pristine and Cr2O3-functionalized ZnO nanorod sensors under UV illumination were examined to determine the effects of combining Cr2O3-ZnO heterostructure formation and UV irradiation on the gas-sensing properties of ZnO nanorods.

NO2 Gas Sensing Properties of Multiple Networked ZnGa2O4 Nanorods Coated with TiO2.

The NO2 gas sensing properties of ZnGa2O4-TiO2 heterostructure nanorods was examined. ZnGa2O4-core/TiO2-shell nanorods were fabricated by the thermal evaporation of a mixture of Zn and GaN powders and the sputter deposition of TiO2. Multiple networked ZnGa2O4-core/TiO2-shell nanorod sensors showed the response of 876% at 10 ppm NO2 at 300 degrees C.

Synthesis, structure, and gas-sensing properties of Pt-functionalized TiO2 nanowire sensors.

TiO2 one-dimensional (1D) nanostrutures were synthesized by using a three-step hydrothermal technique. Subsequently, Pt nanoparticles were coated on the nanowire surface by sputter-deposition of Pt followed by annealing at 800 °C in an Ar atmosphere for 30 min. The morphology, crystal structure, and enhanced sensing characteristics of the TiO2 nanostructures functionalized with Pt to CO and NO2 gases at 300 °C were investigated.

Enhanced near-band edge emission from ZnO nanorods by V2Os coating and subsequent thermal annealing.

V2O5-coated ZnO 1D nanostructures were prepared by using a two step process: thermal evaporation of a mixture of ZnO and graphite powders (ZnO:C = 1:1) in an oxidative atmosphere and sputter-deposition of V2O5. Scanning electron microscopy revealed that the nanostructures had a rod-like morphology with the thickness diminishing gradually from an end to the other. The thicknesses and lengths of the nanorods range from a few tens to a few hundreds of nanometers and from a few to a few tens of micrometers, respectively.

Enhanced gas sensing properties of multiple networked In2O3-core/ZnO-shell nanorod sensors.

The influence of the encapsulation of In2O3 nanorods with ZnO on the H2S gas sensing properties was studied. In2O3-core/ZnO-shell nanorods were fabricated by a two step process comprising the thermal evaporation of an 1:1 mixture of In2O3 and graphite powders and the atomic layer deposition of ZnO. The core-shell nanorods ranged from 100 to 200 nm in diameter and were up to a few hundreds of micrometers in length.

Synthesis, structure and gas-sensing properties of Pd-functionalized ZnSnO3 rods.

ZnSnO3 one-dimensional (1D) strutures were synthesized by using an evaporation technique. The morphology, crystal structure, and enhanced sensing properties of the ZnSnO3 structures functionalized with Pd to CO gas at 300 degrees C were investigated. The diameters of the 1D structures ranged from a few hundreds to a few thousands of nanometers and that the lengths were up to a few hundreds of micrometers.

Hepatoprotective effect of 2,3-dehydrosilybin on carbon tetrachloride-induced liver injury in rats.

The aim of this study was to investigate the protective effect of 2,3-dehydrosilybin (DHS) against carbon tetrachloride (CCl(4))-induced liver injury in rats. Administration of DHS significantly attenuated the levels of serum aspartate aminotransferase, alanine aminotransferase, and liver lipid peroxidation in CCl(4)-treated rats. Moreover, we showed that DHS prevented DNA damage and decreased the protein levels of γ-H2AX, which is a specific DNA damage marker, in CCl(4)-treated rat livers.

Preparation and characterization of MgO nanorods coated with SnO2.

MgO nanorods have been grown by thermal evaporation of Mg3N2 powders on Si (100) substrates coated with gold (Au) thin films. The MgO nanorods grown on Al2O3 (0001) were 0.1-0.

Synthesis of nanograined ZnO nanowires and their enhanced gas sensing properties.

Polycrystalline ZnO nanowires with grain sizes ranging from 20 to 100 nm were synthesized using a newly designed two-step process: (first step) synthesis of ZnSe nanowires by vapor transportation of a mixture of ZnSe powders; and (second step) thermal oxidation of the ZnSe nanowires at 650 °C. Compared to the single-crystal ZnO nanowire gas sensors and other nanomaterial gas sensors reported previously, the multiple networked nanowire gas sensors fabricated from the nanograined ZnO nanowires showed substantially enhanced electrical responses to NO2 gas at 300 °C. The NO2 gas sensing properties of the nanograined ZnO nanowires increased dramatically with increasing NO2 concentration.

Fabrication and optical emission of TiO2-sheathed ZnO nanowires.

The ZnO nanowires were synthesized by using vapor-liquid-solid mechanism and then the ZnO nanowires were sheathed with TiO2 by metal organic chemical vapor deposition. The coaxial nanowires were 30-200 nm in diameter and up to 0.2 microm in length.