The effect of pore structure of zeolite on the adsorption of VOCs and their desorption properties by microwave heating

Mordenite and X- or Y-type faujasite were used to remove volatile organic compounds (VOCs) by adsorption at 25 °C. A microwave heating desorption system was applied for pollutant adsorbent regeneration. Studies were focused on the relationship between the adsorption and/or desorption behavior of selected VOCs (benzene, toluene, o-, m-, p-xylene, methanol, ethanol, iso-propanol, and methylethylketone: MEK) and the physicochemical properties of the zeolites (i.e. acidity, Si/Al ratio, crystal structure, pore structure, surface area, and pore volume) in this work. It was shown that the adsorption behavior of mordenite zeolites with low surface area depended on its crystal structure, while the faujasite zeolites with large surface area depended on the mesopore volume. Faujasite zeolites showed the greatest adsorption capacity for the selected VOCs. It was also shown that the mesopore volume with ink-bottle pores was advantageous for adsorption and, contrarily, the mesopore volume with cylindrical mesopores was advantageous for VOC desorption and zeolite regeneration. High efficiency desorption of VOCs was obtained using microwave heating. The highest microwave heating desorption efficiency was obtained with molecular sieve 13X due to the cylindrical pore structure.Keywords: Adsorption, Desorption, Volatile organic compounds (VOCs), Microwave heating, Zeolit

Bimetallic Pt–Au Nanocatalysts on ZnO/Al₂O₃/Monolith for Air Pollution Control

The catalytic activity of a monolithic catalyst with nanosized Pt and Au particles on ZnO/Al₂O₃ (Pt-Au/ZnO/Al₂O₃/M) prepared by a wash-coat method was examined, specifically for toluene oxidation. FE-SEM image showed clearly the formation of a ZnO/Al₂O₃ layer on the monolith. Nanosized Pt-Au particles on ZnO/Al₂O₃/M with different sizes could be found in the Pt-Au/ZnO/Al₂O₃/M catalyst. The conversion of toluene decreased with increasing toluene concentration and was also largely affected by the feed flow rate The Pt-Au/ZnO/Al₂O₃/M catalysts prepared in this work have almost the same activity (molecules of toluene per second) compared with a powder Pt-Au/ZnO/Al₂O₃ catalyst with the same loadings of Pt and Au components; thus this catalyst could be used in controlling air pollution with very low concentrations and high flow rate.Keywords: Wash-coat, ZnO/Al₂O₃, Monolithic Catalyst, Nanosized Pt-Au Particle, Toluene Oxidatio

A study on utilization of stainless steel wire cloth as a catalyst support

In this work, stainless steel wire cloth (SSWC) for metallic support was thermally treated to increase the adhesive strength of Al₂O₃ by improving superficial roughness. After coating Al₂O₃ on SSWC, Pt particles as a catalytic component were deposited on the Al₂O₃/SSWC. These supports and catalysts were characterized by N₂ gas adsorption, X-ray diffraction (XRD), scanning electron microscopy (SEM) in conjunction with energy dispersive spectroscopy (EDS), and scanning transmission electron microscopy (STEM). The catalytic performance was tested in the ethylene oxidation. The effect of space velocity (GHSV = 2000–8000 h⁻¹) at different temperatures (190 °C and 210 °C) and reproducibility were investigated. The superficial roughness of SSWC was markedly increased by thermal oxidation at 800 °C for 12 h, and good adherence of Al₂O₃ to the SSWC was observed. The obtained Pt/Al₂O₃/SSWC800 catalyst showed excellent catalytic activity in the ethylene oxidation and showed a good reproducibility and stability even after repeated use.Keywords: Ethylene oxidation, SEM, Metallic support, Thermal treatmen

Fabrication of submicron metallic grids with interference and phase-mask holography

Complex, submicron Cu metallic mesh nanostructures are made by electrochemical deposition using polymer templates made from photoresist. The polymer templates are fabricated with photoresist using two-beam interference holography and phase mask holography with three diffracted beams. Freestanding metallic mesh structures are made in two separate electrodepositions with perpendicular photoresist grating templates. Cu mesh square nanostructures having large (52.6%) open areas are also made by single electrodeposition with a photoresist template made with a phase mask. These structures have potential as electrodes in photonic devices

Assessment of Animal Palatability for Domestic Developed Italian Ryegrass \u3cem\u3eLolium multiflorum\u3c/em\u3e Lam. in South Korea

About 5.6 million tons of forage were consumed in ruminant animals in Korea. But, most of them were supplied in rice straw (2 million ton) and more than one million ton of forage was imported from oversea. As a matter of fact, the self-sufficiency rate of high quality forage was 44 % (2.5 million ton). The research institute had started breeding programs of forage varieties (orchardgrass, Tall fescue and Italian ryegrass), Their remarkable breeding program resulted in release of a synthetic species Italian ryegrass (Lolium multiflorum Lam.) which was more cold-tolerant, much higher yielding than introduced varieties and more adapted in paddy field. Most varieties had focused in evaluation of chemical analysis and productivities of dry matter, however assessment of palatability for ruminant was not conducted. For this reason, this report examines the assessment of animal palatability for domestic developed Italian ryegrass in Korea

Wasserstein Geodesic Generator for Conditional Distributions

Generating samples given a specific label requires estimating conditional distributions. We derive a tractable upper bound of the Wasserstein distance between conditional distributions to lay the theoretical groundwork to learn conditional distributions. Based on this result, we propose a novel conditional generation algorithm where conditional distributions are fully characterized by a metric space defined by a statistical distance. We employ optimal transport theory to propose the \textit{Wasserstein geodesic generator}, a new conditional generator that learns the Wasserstein geodesic. The proposed method learns both conditional distributions for observed domains and optimal transport maps between them. The conditional distributions given unobserved intermediate domains are on the Wasserstein geodesic between conditional distributions given two observed domain labels. Experiments on face images with light conditions as domain labels demonstrate the efficacy of the proposed method

High aspect ratio nanoscale metallic structures as transparent electrodes

A novel technique based on the two polymer micro-transfer molding (2-P μTM) for fabricating one dimensional (1D) high aspect ratio nanoscale metallic structures is presented and experimental characterization is described. Glancing angle metal deposition and physical argon ion milling (etching) techniques were also employed in processing. The resulting metallic structures have high transmission (~80%) in the visible spectrum and have superior electrical conductivity (resistance from 2.4 -7.3 Ω) compared to standard indium-tin oxide (ITO) glass. Thus, the high aspect ratio metallic structures are a promising alternative with potentially superior performances to ITO glass as transparent electrodes for organic solar cells

EFFECT OF LOW DOSE RADIATION ON DIFFERENTIATION OF BONE MARROW CELLS INTO DENDRITIC CELLS

Low dose radiation has been shown to be beneficial to living organisms using several biological systems, including immune and hematopoietic systems. Chronic low dose radiation was shown to stimulate immune systems, resulting in controlling the proliferation of cancer cells, maintain immune balance and induce hematopoietic hormesis. Since dendritic cells are differentiated from bone marrow cells and are key players in maintaining the balance between immune activation and tolerance, it may be important to further characterize whether low dose radiation can influence the capacity of bone marrow cells to differentiate into dendritic cells. We have shown that bone marrow cells from low dose- irradiated (γ-radiation, 0.2Gy, 15.44mGy/h) mice can differentiate into dendritic cells that have several different characteristics, such as expression of surface molecules, cytokine secretion and antigen uptake capacity, when compared to dentritic cells differentiated from the control bone marrow cells. These differences observed in the low dose radiation group can be beneficial to living organisms either by activation of immune responses to foreign antigens or tumors, or maintenance of self-tolerance. To the best of our knowledge, this is the first report showing that total-body low dose radiation can modulate the capacity of bone marrow cells to differentiate into dendritic cells

Visfatin Induces Sickness Responses in the Brain

BACKGROUND/OBJECTIVE: Visfatin, also known as nicotiamide phosphoribosyltransferase or pre-B cell colony enhancing factor, is a pro-inflammatory cytokine whose serum level is increased in sepsis and cancer as well as in obesity. Here we report a pro-inflammatory role of visfatin in the brain, to mediate sickness responses including anorexia, hyperthermia and hypoactivity. METHODOLOGY: Rats were intracerebroventricularly (ICV) injected with visfatin, and changes in food intake, body weight, body temperature and locomotor activity were monitored. Real-time PCR was applied to determine the expressions of pro-inflammatory cytokines, proopiomelanocortin (POMC) and prostaglandin-synthesizing enzymes in their brain. To determine the roles of cyclooxygenase (COX) and melanocortin in the visfatin action, rats were ICV-injected with visfatin with or without SHU9119, a melanocortin receptor antagonist, or indomethacin, a COX inhibitor, and their sickness behaviors were evaluated. PRINCIPAL FINDINGS: Administration of visfatin decreased food intake, body weight and locomotor activity and increased body temperature. Visfatin evoked significant increases in the levels of pro-inflammatory cytokines, prostaglandin-synthesizing enzymes and POMC, an anorexigenic neuropeptide. Indomethacin attenuated the effects of visfatin on hyperthermia and hypoactivity, but not anorexia. Further, SHU9119 blocked visfatin-induced anorexia but did not affect hyperthermia or hypoactivity. CONCLUSIONS: Visfatin induced sickness responses via regulation of COX and the melanocortin pathway in the brain