Accelerating Sulfated Polysaccharides Extraction from Fast-Growing Green Seaweed by Frequency-Controlled Microwaves.

sp. is a type of green algae and is widely distributed in coastal areas around the world due to eutrophication. Effective utilization of sp.

Zinc chloride-catalyzed Grignard addition reaction of aromatic nitriles.

In the alkyl addition reaction of aromatic nitriles using Grignard reagents, ketones are formed after hydrolysis. However, this addition reaction is often slow compared to that using reactive organolithium(i) reagents. In this study, we improved the reaction by using zinc(ii)ates, which are generated using Grignard reagents and zinc chloride (ZnCl) as a catalyst.

Self-Sufficient Production of Lunar Regolith Gravels on the Moon by Ultrarapid Microwave Sintering.

A sintered lunar regolith is expected to be used to construct buildings, roads, and landing pads for spacecrafts on the Moon. Here, we demonstrate that focused microwave heating is effective for the rapid solidification of the lunar regolith simulant to obtain regolith gravel without any microwave susceptor. The conventional multimode microwave oven cannot heat lunar regolith simulants and requires microwave susceptors such as silicon carbide (SiC) and thermal insulators because of its low dielectric loss.

Gas6 ameliorates intestinal mucosal immunosenescence to prevent the translocation of a gut pathobiont, Klebsiella pneumoniae, to the liver.

Immunosenescence refers to the development of weakened and/or dysfunctional immune responses associated with aging. Several commensal bacteria can be pathogenic in immunosuppressed individuals. Although Klebsiella pneumoniae is a commensal bacterium that colonizes human mucosal surfaces, the gastrointestinal tract, and the oropharynx, it can cause serious infectious diseases, such as pneumonia, urinary tract infections, and liver abscesses, primarily in elderly patients.

Expansion of Photostable Luminescent Radicals by Meta-Substitution.

Polychlorinated pyridyldiphenylmethyl radicals having substituents meta to the position bearing the carbon-centered radical (α-carbon) are synthesized. All of them are stable in ambient conditions in solutions and fluorescent in cyclohexane. The fluorescence of the radicals with bromo, phenyl, 4-chlorophenyl, or 2-pyridyl substituents are enhanced in chloroform, while the emission of the radicals with 2-thienyl or 2-furyl substituents are quenched in chloroform.

Real-Time Facile Detection of the WO Catalyst Oxidation State under Microwaves Using a Resonance Frequency.

Microwaves (MWs) are often used to enhance various heterogeneous catalytic reactions. Here, we demonstrate real-time monitoring of a catalyst's oxidation state in a microwave catalytic reaction using a resonance frequency. The changes in the catalyst's oxidation state during the reaction induced changes in the resonance frequency in the cavity resonator.

Fourfold daily growth rate in multicellular marine alga Ulva meridionalis.

Microalgae with high growth rates have been considered as promising organisms to replace fossil resources with contemporary primary production as a renewable source. However, their microscopic size makes it hard to be harvested for industrial applications. In this regard, multicellular macroalgae are more suitable for harvesting.

Probing the temperature of supported platinum nanoparticles under microwave irradiation by in situ and operando XAFS.

Microwave irradiation can cause high local temperatures at supported metal nanoparticles, which can enhance reaction rates. Here we discuss the temperature of platinum nanoparticles on γ-AlO and SiO supports under microwave irradiation using the Debye-Waller factor obtained from in situ extended X-ray absorption fine structure (EXAFS) measurements. Microwave irradiation exhibits considerably smaller Deby-Waller factors than conventional heating, indicating the high local temperature at the nanoparticles.

Microwave Irradiation Process for Al-Sc Alloy Production.

Scandium is being explored as an alloying element for aluminium alloys, which are gaining importance as high-performance lightweight structural alloys in the transportation industry. Sc-rich ScAlN thin films show strong piezoelectricity and can be fabricated on a hard substrate for use as wideband surface acoustic wave filters in next-generation wireless mobile communication systems. However, the use of ScAlN thin films in microelectromechanical system devices is limited by the high cost of metallic Sc, which is due to the difficulty in smelting of this material.

Kinetic analysis of microwave-enhanced cellulose dissolution in ionic solvents.

Cellulose dissolution in mixtures of the ionic liquid 1-ethyl-3-methylimidazolium acetate with dimethylsulfoxide, [CCIm][OAc] + DMSO, have been kinetically compared using conventional heating and microwave heating in a single-mode cavity with a semiconductor generator. Microwaves led to enhancements in the dissolution rate between 21 and 57% under different conditions of temperature and concentration of ionic liquid. Rate enhancement by microwaves prominently occurred at temperatures above 60 °C.

Fractionation of plant-cuticle-based bio-oils by microwave-assisted methanolysis combined with hydrothermal pretreatment and enzymatic hydrolysis.

Microwave-assisted methanolysis was performed to fractionate a mixture of fatty acid methyl-esters from the cuticles of various wild plants and agricultural wastes. A combination of hydrothermal pretreatment and enzymatic hydrolysis effectively removed hemicellulose and cellulose to afford plant cuticles concentrated in residual materials. The subsequent methanolysis treatment afforded bio-oil from plant cuticles in ∼10% yield with a maximum higher heating value (HHV) of 32 MJ kg from bagasse.

Remote Control of Electron Transfer Reaction by Microwave Irradiation: Kinetic Demonstration of Reduction of Bipyridine Derivatives on Surface of Nickel Particle.

Microwave irradiation has great potential to control chemical reactions remotely, particularly reactions that involve electron transfer. In this study, we found that the reduction reaction of bipyridine derivatives on metal nickel particles was accelerated or decelerated by 2.45 GHz microwaves without an alteration of the reaction temperature.

Raman monitoring of dielectric-heating-enhanced freeze-drying under different electromagnetic wave frequencies.

We studied the effect of dielectric heating on the enhancement of freeze-drying by electromagnetic waves (EMWs) under different frequencies: 2.45 GHz microwaves (MWs), and 27 and 200 MHz radio frequencies (RFs). The irradiation with RFs, particularly at 27 MHz, reduced the duration of freeze-drying by 67%.

Enhancement of Fixed-bed Flow Reactions under Microwave Irradiation by Local Heating at the Vicinal Contact Points of Catalyst Particles.

The formation of local high temperature regions, or so-called "hot spots", in heterogeneous reaction systems has been suggested as a critical factor in the enhancement of chemical reactions using microwave heating. In this paper, we report the generation of local high temperature regions between catalyst particles under microwave heating. First, we demonstrated that reaction rate of the dehydrogenation of 2-propanol over a magnetite catalyst was enhanced 17- (250 °C) to 38- (200 °C) fold when heated with microwave irradiation rather than an electrical furnace.

Radio frequency alternating electromagnetic field enhanced tetraruthenium polyoxometalate electrocatalytic water oxidation.

Application of radio frequency (RF) electromagnetic waves enhances the electrocatalytic water oxidation by protonated tetraruthenium polyoxometalate ([Ru4(μ-O)4(μ-OH)2(H2O)4(γ-SiW10O36)2]10-). In particular, an enhancement factor of 3.6 is achieved when the level of proton substitution of protonated tetraruthenium polyoxometalate is changed from zero to 9 under application of RF at 200 MHz.

Tuning strain-induced γ-to-ε martensitic transformation of biomedical Co-Cr-Mo alloys by introducing parent phase lattice defects.

In this study, we examined the effect of pre-existing dislocation structures in a face-centered cubic γ-phase on strain-induced martensitic transformation (SIMT) to produce a hexagonal close-packed ε-phase in a hot-rolled biomedical Co-Cr-Mo alloy. The as-rolled microstructure was characterized by numerous dislocations as well as stacking faults and deformation twins. SIMT occurred just after macroscopic yielding in tensile deformation.

Proton-Enhanced Dielectric Properties of Polyoxometalates in Water under Radio-Frequency Electromagnetic Waves.

Electromagnetic waves, such as microwaves, have been used to enhance various chemical reactions over polyoxometalates. The dielectric properties of catalysts are among the relevant parameters facilitating catalytic reactions under electromagnetic radiation. This study describes the dielectric properties of polyoxometalate catalysts in aqueous and organic solutions to understand the mechanism of interactions between polyoxometalates and electromagnetic waves.

Effect of Aspect Ratio on the Permittivity of Graphite Fiber in Microwave Heating.

Microwave (MW) heating has received attention as a new heating source for various industrial processes. Some materials are expected to be a more effective absorber of MW, and graphite is observed as a possible candidate for high-temperature application. We investigated the dependence of the aspect ratio of graphite fibers on both their heating behavior and permittivity under a 2.

Smelting of Scandium by Microwave Irradiation.

Scandium is being explored as an alloying element for aluminum alloys, which are gaining importance as high-performance lightweight structural alloys in the transportation industry. A few years ago, Sc was also found to be suitable for use in electrical devices. High-Sc-content ScAlN thin films have attracted significant attention because of their strong piezoelectricity.

Sex determination based on a thoracic vertebra and ribs evaluation using clinical chest radiography.

Our aim was to investigate whether sex can be determined from a combination of geometric features obtained from the 10th thoracic vertebra, 6th rib, and 7th rib. Six hundred chest radiographs (300 males and 300 females) were randomly selected to include patients of six age groups (20s, 30s, 40s, 50s, 60s, and 70s). Each group included 100 images (50 males and 50 females).

Smelting Magnesium Metal using a Microwave Pidgeon Method.

Magnesium (Mg) is a lightweight metal with applications in transportation and sustainable battery technologies, but its current production through ore reduction using the conventional Pidgeon process emits large amounts of CO and particulate matter (PM2.5). In this work, a novel Pidgeon process driven by microwaves has been developed to produce Mg metal with less energy consumption and no direct CO emission.

Enhancement of anodic current attributed to oxygen evolution on α-FeO electrode by microwave oscillating electric field.

Various microwave effects on chemical reactions have been observed, reported and compared to those carried out under conventional heating. These effects are classified into thermal effects, which arise from the temperature rise caused by microwaves, and non-thermal effects, which are attributed to interactions between substances and the oscillating electromagnetic fields of microwaves. However, there have been no direct or intrinsic demonstrations of the non-thermal effects based on physical insights.