Comparing the contribution of visible-light irradiation, gold nanoparticles, and titania supports in photocatalytic nitroaromatic coupling and aromatic alcohol oxidation

Under visible-light irradiation, gold nanoparticles (Au NPs) supported by titania (TiO₂) nanofibers show excellent activity and high selectivity for both reductive coupling of nitroaromatics to corresponding azobenzene or azoxylbenzene and selective oxidation of aromatic alcohols to corresponding aldehydes. The Au NPs act as active centers mainly due to their localized surface plasmon resonance (LSPR) effect. They can effectively couple the photonic energy and thermal energy to enhance reaction efficiency. Visible-light irradiation has more influence on the reduction than on the oxidation, lowering the activation energy by 24.7 kJ mol⁻¹ and increasing the conversion rate by 88% for the reductive coupling, compared to merely 8.7 kJ mol⁻¹ and 46% for the oxidation. Furthermore, it is found that the conversion of nitroaromatics significantly depends on the particle size and specific surface area of supported Au NPs; and the catalyst on TiO₂(B) support outperforms that on anatase phase with preferable ability to activate oxygen. In contrast, for the selective oxidation, the effect of surface area is less prominent and Au NPs on anatase exhibit higher photo-catalytic activity than other TiO₂ phases. The catalysts can be recovered efficiently because the Au NPs stably attach to TiO₂ supports by forming a well-matched coherent interface observed via high-resolution TEM

From insulator to quantum Hall liquid at low magnetic fields

We have performed low-temperature transport measurements on a GaAs two-dimensional electron system at low magnetic fields. Multiple temperature-independent points and accompanying oscillations are observed in the longitudinal resistivity between the low-field insulator and the quantum Hall (QH) liquid. Our results support the existence of an intermediate regime, where the amplitudes of magneto-oscillations can be well described by conventional Shubnikov-de Haas theory, between the low-field insulator and QH liquid.Comment: Magneto-oscillations governed by Shubnikov-de Haas theory are observed between the low-field insulator and quantum Hall liqui

Flow Boiling Pressure Drop for R410A and RL32H in Multi-channel Tube

This paper introduced a test facility to conduct both flow boiling and condensation test in a multi-channel tube, including structure designs in test section to maintain good and stable flow regime in multi-channels. It supports flow boiling and condensing testing at the same time. The refrigerant cycle was driven by a gear pump, liquid refrigerant flows from the gear pump, passes through an electrical pre-heater, evaporator and post-heater, then flow through water/glycol bath pre-condenser, condenser and post-condenser. Experimental data for pure R410A, R410A and lubricant RL32H mixture pressure drop in flow boiling is presented and analyzed in this paper. Inlet vapor quality was changing at 0.2, 0.4, 0.6 to 0.8 with 0.2 quality increase along the tube, mass fraction of lubricant was changing from 0%, 1%, 3% to 5%, and mass velocity of the pure and mixture varied from 100 to 700 kg s-1 m-2. The experiments have been conducted for average saturation temperature at 5ºC. Literatures on two phase flow boiling pressure drop for both pure refrigerant and refrigerant mixtures are carefully reviewed, popular published correlations are used in this study to evaluate test data. New two phase flow boiling pressure drop correlations for pure refrigerant and mixtures inside multi-channel tube are proposed. Some published data are used to validate new correlations

Gravity waves over topographical bottoms: Comparison with the experiment

In this paper, the propagation of water surface waves over one-dimensional periodic and random bottoms is investigated by the transfer matrix method. For the periodic bottoms, the band structure is calculated, and the results are compared to the transmission results. When the bottoms are randomized, the Anderson localization phenomenon is observed. The theory has been applied to an existing experiment (Belzons, et al., J. Fluid Mech. {\bf 186}, 530 (1988)). In general, the results are compared favorably with the experimental observation.Comment: 15 pages, 7 figure

Priprava toplinskoizolacijske žbuke s FGD-gipsom

Thermal insulation gypsum plaster was prepared from flue gas desulphurization (FGD) gypsum. K12 is more recommendable as foaming agent, when the mass fraction of K12 is around 0.1 %, the setting time and compressive strength meet the requirements of gypsum-based construction materials. In the meanwhile, the thermal conductivity is 0.18 W m–1 K–1, which can be used as a thermal insulation material. The hemihydrate mixtures obtained, allow the design of a new wall structure, which is more efficient as a thermal insulation system. The wall heat transfer coefficient test was carried out to compare thermal performance of two different thermal insulation systems. Compared with the thermal performance of a conventional system, the heat transfer coefficient of the new system was reduced by 5.6 %. Finally, energy-saving analysis of a building was carried out to compare the energy-saving effect of the conventional and new systems of building. The energy-savings of the building with the new system increased by almost 2 %, thus resulting in low energy consumption of the building.Toplinskoizolacijska gipsana žbuka izrađena je od gipsa nastalog odsumporavanjem dimnog plina (FGD). Uz maseni udjel sredstva za pjenjenje (K12) 0,1 % toplinska provodnost iznosi 0,18 W m–1 K–1 pa se materijal može upotrijebiti za toplinsku izolaciju. Žbuka i sredstvo za pjenjenje uključeni su u novi tip zidne toplinske izolacije. Koeficijent prijenosa topline novog izolacijskog sustava određen je eksperimentalno i iznosi 0,608 W m–2 K–1. Na temelju analize zaključeno je da se s novim sustavom ušteda energije u zgradi može popeti do 66,99 %. Novi materijal može imati velik utjecaj na energijsku učinkovitost zgrade

Abnormal Gastroscopy Findings Were Related to Lower Meridian Energy

According to the theories of Traditional Chinese Medicine (TCM), energy runs through 12 meridians longitudinally up and down the body. The study objectives were to compare the meridian energy between subjects with and without abnormal gastroscopy findings. We applied a cross-sectional and correlational research design. The study included 1,223 participants who had their health examinations at a university hospital in Taipei from 1st August 2005 through 31st August 2007. Meridian energy was examined using a meridian energy analysis device. The gastroscopy was operated by certified gastroenterologists. Participants with abnormal stomach and esophageal findings using gastroscopy had significantly lower mean meridian energy. There were no significant differences in meridian energy between participants with and without abnormal duodenum findings. When all of the meridians were examined individually, participants with abnormal findings in esophagus and stomach had significantly lower meridian energy in each of the meridians. The results of this study demonstrated that structural abnormality in the gastric area was related to lower meridian energy. Whether enhancing meridian energy could improve gastric and esophageal health merits further studies

Understanding the Impact of Service Failure and Recovery Justice on Consumers’ Satisfaction and Repurchase Intention

This research attempts to explore the impacts of different types of justice and their interactions on the satisfaction toward service failure recovery. We attempt to classify justices into hygiene, motivator, or asymmetric variable, based on the concept of asymmetric effect and two factors theory proposed by Herzberg. Specifically, we predict that procedural and distributive justices are hygiene or performance factor and interpersonal justice is motivator. In addition, based on expectancy-disconfirmation theory (EDT), we also attempt to understand the interaction between paired justices by arguing that motivator can generate more effect when hygiene factor or performance factors meet initial expectation. An experiment, with 3x2x2 between-subjects factorial design consisting of three factors to represent different levels of justice provided by online retailer, will be conducted to test the proposed hypotheses. A two-step approach will be used to (1) confirmation the types (hygiene, performance, or motivator) that each justice dimension belongs to, (2) understand the impact of each justice on satisfaction, and (3) test whether motivator will generate more effect when hygiene and performance factor are satisfied