The hydrogen economy has been identified as an alternative to substitute the non-sustainable fossil fuel based economy. Ongoing research is underway to develop environmentally friendly and economical ...hydrogen production technologies that are essential for the hydrogen economy. One of the promising ways to produce hydrogen is to use aluminum or its alloys to reduce water or hydrocarbons to hydrogen. This paper gives an overview on these aluminum-based hydrogen production methods, their limitations and challenges for commercialization. Also, a newly developed concept for cogeneration of hydrogen and electrical energy is discussed.
In this study, the characteristics and performance of three commonly used catalysts used for alkaline-catalyzed transesterification i.e. sodium hydroxide, potassium hydroxide and sodium methoxide, ...were evaluated using edible Canola oil and used frying oil. The fuel properties of biodiesel produced from these catalysts, such as ester content, kinematic viscosity and acid value, were measured and compared. With intermediate catalytic activity and a much lower cost sodium hydroxide was found to be more superior than the other two catalysts. The process variables that influence the transesterification of triglycerides, such as catalyst concentration, molar ratio of methanol to raw oil, reaction time, reaction temperature, and free fatty acids content of raw oil in the reaction system, were investigated and optimized. This paper also studied the influence of the physical and chemical properties of the feedstock oils on the alkaline-catalyzed transesterification process and determined the optimal transesterification reaction conditions that produce the maximum ester content and yield.
Graphene, composed of single-layered sp2 graphite, with its superb physical and chemical properties, has attracted scientists in different areas, including electronics, medicine, and chemicals. Its ...applications in green energy were extensively studied in the past two decades. Results from different studies show that graphene-based products with different structures (2D and 3D graphene) can effectively enhance green energy conversion and storage compared to traditional energy materials like metal and metal oxides. This review focuses on the historical development of graphene, the variation of graphene products, and mainstream researches in graphene-based green energy applications carried out in recent years, such as fuel cell, solar cell, lithium-ion batteries (LIBs), supercapacitor, dye-sensitized solar cell (DSSC), and photoelectrochemical water-splitting cell. The development of graphene-based materials integrated with different 3D printing technology and the application of their products in green energy are also discussed together with a forecast on the development of graphene-based materials in the future.
•Development of raw graphene (bottom-up and top-down) is highlighted.•Various modifications of graphene-based materials for energy applications are reviewed.•Use of graphene-based materials in green energy electrodes is discussed.•Recent development of graphene in green energy via 3D printing is introduced.•Perspective on graphene energy materials development is given.
Background
Gut microbiota may play a role in egg allergy. We sought to examine the association between early‐life gut microbiota and egg allergy.
Methods
We studied 141 children with egg allergy and ...controls from the multicenter Consortium of Food Allergy Research study. At enrollment (age 3 to 16 months), fecal samples were collected, and clinical evaluation, egg‐specific IgE measurement, and egg skin prick test were performed. Gut microbiome was profiled by 16S rRNA sequencing. Analyses for the primary outcome of egg allergy at enrollment, and the secondary outcomes of egg sensitization at enrollment and resolution of egg allergy by age 8 years, were performed using Quantitative Insights into Microbial Ecology, Phylogenetic Investigation of Communities by Reconstruction of Unobserved States, and Statistical Analysis of Metagenomic Profiles.
Results
Compared to controls, increased alpha diversity and distinct taxa (PERMANOVA P = 5.0 × 10−4) characterized the early‐life gut microbiome of children with egg allergy. Genera from the Lachnospiraceae, Streptococcaceae, and Leuconostocaceae families were differentially abundant in children with egg allergy. Predicted metagenome functional analyses showed differential purine metabolism by the gut microbiota of egg‐allergic subjects (Kruskal‐Wallis Padj = 0.021). Greater gut microbiome diversity and genera from Lachnospiraceae and Ruminococcaceae were associated with egg sensitization (PERMANOVA P = 5.0 × 10−4). Among those with egg allergy, there was no association between early‐life gut microbiota and egg allergy resolution by age 8 years.
Conclusion
The distinct early‐life gut microbiota in egg‐allergic and egg‐sensitized children identified by our study may point to targets for preventive or therapeutic intervention.
PD-L1 immunohistochemistry correlates only moderately with patient survival and response to PD-(L)1 treatment. Heterogeneity of tumor PD-L1 expression might limit the predictive value of small ...biopsies. Here we show that tumor PD-L1 and PD-1 expression can be quantified non-invasively using PET-CT in patients with non-small-cell lung cancer. Whole body PD-(L)1 PET-CT reveals significant tumor tracer uptake heterogeneity both between patients, as well as within patients between different tumor lesions.
Abstract
Catastrophic failure in brittle, porous materials initiates when smaller-scale fractures localise along an emergent fault zone in a transition from stable crack growth to dynamic rupture. ...Due to the rapid nature of this critical transition, the precise micro-mechanisms involved are poorly understood and difficult to image directly. Here, we observe these micro-mechanisms directly by controlling the microcracking rate to slow down the transition in a unique rock deformation experiment that combines acoustic monitoring (sound) with contemporaneous in-situ x-ray imaging (vision) of the microstructure. We find seismic amplitude is not always correlated with local imaged strain; large local strain often occurs with small acoustic emissions, and vice versa. Local strain is predominantly aseismic, explained in part by grain/crack rotation along an emergent shear zone, and the shear fracture energy calculated from local dilation and shear strain on the fault is half of that inferred from the bulk deformation.
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•Single Co atom catalyst (Co@Al-SiO2) was well designed by defect engineering.•Surface-bound sulfate SO4− was produced from Co@Al-SiO2 activation of PMS.•Multiple approaches were ...developed to quantitatively identify surface-bound SO4−.•Surface-bound SO4− boost the degradation kinetics of organic contaminants.
Surface-bound radicals have been reported to be emerging crucial reactive species in Fenton-like reactions for environmental treatment. However, their identification on catalyst surface and contribution to pollutant degradation have never been well addressed. In this study, single Co atom anchored on Al-doped SiO2 (Co@Al-SiO2) catalyst was well designed for peroxymonosulfate (PMS) activation to produce a high concentration of surface-bound sulfate radicals (SO4−) and reached 100 % removal percentage of antibiotics, dyes and volatile organic compounds (VOCs) pollutants within several minutes. In-situ cyclic voltammetry-electrochemical quartz crystal microbalance (CV-EQCM) and the derived calculation method were firstly employed to quantitatively identify the surface-bound SO4−. Results show that abundant surface-bound SO4− was generated on Co-Si bond and its concentration reached 1.17 × 10−6 mol/m2, which was very close to the theoretical maximum (1.34 × 10−6 mol/m2). Further experiments demonstrated that Co atoms can provide rich binding sites for SO4−, resulting in the enrichment of surface-bound SO4− in nanoscale surface. This behavior can remarkably boost the degradation kinetics towards various organic contaminants. Coupled with a membrane in water treatment, this system showed an outstanding performance for degradation of pollutants such as dyes (>99 %) with the flow rate of 20 ml/min after 0.5 s, which was considerably faster than traditional treatments. This study provides a fundamental insight into surface-bound radical, guiding the rational design of catalyst for Fenton-like reactions in environmental application.
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