Double-Inverse-Opal-Structured Particle Assembly as a Novel Immobilized Photocatalytic Material

Immobilization of photocatalysts on supports is an important method of adding highly active photocatalysts to a continuous flowing system without the need for photocatalyst recovery. However, direct immobilization prevents exposure to all photocatalytically active surfaces. Therefore, to immobilize particulate photocatalysts, while exposing the photocatalytic surface to organic pollutant water in a continuous flowing system, in this study, we employed double-inverse-opal (DIO) with periodically arranged, interconnected macropores, each containing a single photocatalytic particle. Increasing the macropore size successfully enhanced the decomposition rate of organic dye due to the high diffusion rate of dye molecules in the macropores of thin DIOs. However, an excessive increase in macropore size lowered the decomposition rate of dye molecules because an increase in DIO thickness caused the attenuation of light used to excite the photocatalytic particles. This study presents novel, immobilized photocatalytic DIO-structured particles that can be employed in continuous flowing reaction systems by tuning the photocatalytic particle size, macropore size, and DIO thickness.

Redox Regulation of Homeostasis and Proteostasis in Peroxisomes

Peroxisomes are highly dynamic intracellular organelles involved in a variety of metabolic functions essential for the metabolism of long-chain fatty acids, d-amino acids, and many polyamines. A byproduct of peroxisomal metabolism is the generation, and subsequent detoxification, of reactive oxygen and nitrogen species, particularly hydrogen peroxide (H2O2). Because of its relatively low reactivity (as a mild oxidant), H2O2 has a comparatively long intracellular half-life and a high diffusion rate, all of which makes H2O2 an efficient signaling molecule. Peroxisomes also have intricate connections to mitochondria, and both organelles appear to play important roles in regulating redox signaling pathways. Peroxisomal proteins are also subject to oxidative modification and inactivation by the reactive oxygen and nitrogen species they generate, but the peroxisomal LonP2 protease can selectively remove such oxidatively damaged proteins, thus prolonging the useful lifespan of the organelle. Peroxisomal homeostasis must adapt to the metabolic state of the cell, by a combination of peroxisome proliferation, the removal of excess or badly damaged organelles by autophagy (pexophagy), as well as by processes of peroxisome inheritance and motility. More recently the tumor suppressors ataxia telangiectasia mutate (ATM) and tuberous sclerosis complex (TSC), which regulate mTORC1 signaling, have been found to regulate pexophagy in response to variable levels of certain reactive oxygen and nitrogen species. It is now clear that any significant loss of peroxisome homeostasis can have devastating physiological consequences. Peroxisome dysregulation has been implicated in several metabolic diseases, and increasing evidence highlights the important role of diminished peroxisomal functions in aging processes.

Oxygen-induced high diffusion rate of magnesium dopants in GaN/AlGaN based UV LED heterostructures

Oxygen breaks up Mg–H complexes and induces high diffusion of Mg in GaN/AlGaN heterostructures.

DIMENSIONALLY STABLE WATER-BLOWN POLYURETHANE FOAM EXTENDED WITH BIO-BASED PROPYLENE GLYCOL AND MODIFIED WITH PAPER WASTE SLUDGE

Paper waste sludge (PWS) is the main and the greatest by-product in paper production process, and its elimination as well as destruction is a primary environmental problem. This research explores the feasibility of such wastes to be used in polyurethane foam composites. It is well known that using water as a sole blowing agent has major drawbacks such as long demould time, shrinkage, high diffusion rate of carbon dioxide and etc.; therefore, the bio-based propylene glycol (RPG) is used in order to solve such problems. The addition of 20 parts by weight (pbw) of RPG eliminates the primary shrinkage of the foam composites when PWS is used in the amount varying from 5% to 20%, and improves the dimensional stability at 70 oC and 90% relative humidity conditions. The addition of titanate coupling agent modified PWS particles increases the compressive strength of the final composites from ̴ 26% to ̴ 53%, from ̴ 17% to ̴ 31% and from ̴ 3% to ̴ 23% for, respectively, 10 pbw, 15 pbw and 20 pbw RPG extended foam composites.

Improved impregnation efficiency and pulp yield of softwood kraft pulp by high effective alkali charge in the impregnation stage

A pulp yield increase up to 2% can be achieved by impregnation with a liquor containing 2 M effective alkali (EA) concentration instead of 1 M. The yield increase is due to higher cellulose and glucomannan contents in the pulp, which can be rationalized by less yield loss by peeling, as impregnation is more effective at an elevated EA level. A rapid loading of chips with alkali can be realized due to a high diffusion rate. When the temperature becomes higher in the cooking stage, enough alkali is available for delignification reactions without the risk of alkali depletion in the chip core, so that the delignification is more homogeneous.

Surface ligand-mediated isolated growth of Pt on Pd nanocubes for enhanced hydrogen evolution activity

Br− ions can affect the growth mode of Pt on a Pd substrate. When Br− ions adsorb on some sites of the Pd cube, the newly formed Pt atoms tended to grow on the Br− free area, facilitating island growth mode. Otherwise, without Br− ions, because of the relatively high diffusion rate between Pt and Pd, Pt atoms can epitaxially deposit on the whole surface of the Pd nanocubes, forming a layered growth mode structure.

Optimisation of Diffusion Bonding Parameters of Ti Alloys through the Structure and Surface Conditions

Diffusion bonding of Ti-6Al-4V titanium alloy in the coarse grained and ultrafine grained state was performed. The effect of initial structure and surface condition, as well as temperature and time, on the quality of joints was established. It is shown that, due to low-temperature superplasticity and high diffusion rate, samples with ultrafine grained structure demonstrate better bondability than coarse grained samples

The effects of coating structure and water-holding capacity on the oxygen-scavenging ability of enzymes embedded in the coating layer

Enzymes catalyzing oxygen scavenging were embedded in latex-based coatings with and without barrier kaolin clay to produce material for active packages. The clay was used to create a porous structure, and the closed-structure matrix consisted of a biopolymer comprising either starch or gelatin to increase the water uptake of the coating. The effects of the porous open structure and of the water uptake of the coated layer on the oxygen-scavenging ability of the embedded enzymes were examined at both 75% and 100% relative humidity. The results showed that the porous clay structure led to higher oxygen-scavenging capacity than that of a closed structure at both test conditions by enabling a high diffusion rate for oxygen and glucose to the active sites of the enzymes. The addition of a water-holding biopolymer did not always significantly affect the oxygen-scavenging capacity. However for a less-porous layer at 100% relative humidity, an increase in the amount of biopolymer resulted in an increase in oxygen-scavenging capacity. The results were treated statistically using multiple-factor analysis where the most important factor for the oxygen-scavenging ability was found to be the addition of clay. The coatings were also characterized with respect to water vapor uptake, overall migration, porosity, and scanning electron microscopy images.