Hasil untuk "Chemical industries"

H. Strathmann

P. Vlieghe, V. Lisowski, Jean Martinez et al.

Ryan L. Hartman, J. McMullen, K. Jensen

L. Pawłowski

B. Cushing, V. Kolesnichenko, C. O'connor

A. Dömling, I. Ugi

Marius Amereller, M. Whittingham

J. Griffin, J. Mahon

J. Campos-Martín, G. Blanco-Brieva, J. Fierro

Shubham Sharma, Sandra Barkauskaite, Amit K. Jaiswal et al.

Food packaging can be considered as a passive barrier that protects food from environmental factors such as ultraviolet light, oxygen, water vapour, pressure and heat. It also prolongs the shelf-life of food by protecting from chemical and microbiological contaminants and enables foods to be transported and stored safely. Active packaging (AP) provides the opportunity for interaction between the external environment and food, resulting in extended shelf-life of food. Chemoactive packaging has an impact on the chemical composition of the food product. The application of natural additive such as essential oils in active packaging can be used in the forms of films and coatings. It has been observed that, AP helps to maintain temperature, moisture level and microbial and quality control of the food. This review article provides an overview of the active packaging incorporated with essential oils, concerns and challenges in industry, and the effect of essential oil on the packaging microstructure, antioxidant and antimicrobial properties.

Xiuyun Sun, Hongying Gao, Yiqing Yang et al.

Although many kinds of therapies are applied in the clinic, drug-resistance is a major and unavoidable problem. Another disturbing statistic is the limited number of drug targets, which are presently only 20–25% of all protein targets that are currently being studied. Moreover, the focus of current explorations of targets are their enzymatic functions, which ignores the functions from their scaffold moiety. As a promising and appealing technology, PROteolysis TArgeting Chimeras (PROTACs) have attracted great attention both from academia and industry for finding available approaches to solve the above problems. PROTACs regulate protein function by degrading target proteins instead of inhibiting them, providing more sensitivity to drug-resistant targets and a greater chance to affect the nonenzymatic functions. PROTACs have been proven to show better selectivity compared to classic inhibitors. PROTACs can be described as a chemical knockdown approach with rapidity and reversibility, which presents new and different biology compared to other gene editing tools by avoiding misinterpretations that arise from potential genetic compensation and/or spontaneous mutations. PRTOACs have been widely explored throughout the world and have outperformed not only in cancer diseases, but also in immune disorders, viral infections and neurodegenerative diseases. Although PROTACs present a very promising and powerful approach for crossing the hurdles of present drug discovery and tool development in biology, more efforts are needed to gain to get deeper insight into the efficacy and safety of PROTACs in the clinic. More target binders and more E3 ligases applicable for developing PROTACs are waiting for exploration.

K. Moon, E. Kwon, Bonggi Lee et al.

Enzymatic browning because of polyphenol oxidases (PPOs) contributes to the color quality of fruit and vegetable (FV) products. Physical and chemical methods have been developed to inhibit the activity of PPOs, and several synthetic chemical compounds are commonly being used as PPO inhibitors in FV products. Recently, there has been an emphasis on consumer-oriented innovations in the food industry. Consumers tend to urge the use of natural and environment-friendly PPO inhibitors. The purpose of this review is to summarize the mechanisms underlying the anti-browning action of chemical PPO inhibitors and current trends in the research on these inhibitors. Based on their mechanisms of action, chemical inhibitors can be categorized as antioxidants, reducing agents, chelating agents, acidulants, and/or mixed-type PPO inhibitors. Here, we focused on the food ingredients, dietary components, food by-products, and waste associated with anti-browning activity.

Célia C. G. Silva, Sofia P M Silva, S. Ribeiro

In the last years, consumers are becoming increasingly aware of the human health risk posed by the use of chemical preservatives in foods. In contrast, the increasing demand by the dairy industry to extend shelf-life and prevent spoilage of dairy products has appeal for new preservatives and new methods of conservation. Bacteriocins are antimicrobial peptides, which can be considered as safe since they can be easily degraded by proteolytic enzymes of the mammalian gastrointestinal tract. Also, most bacteriocin producers belong to lactic acid bacteria (LAB), a group that occurs naturally in foods and have a long history of safe use in dairy industry. Since they pose no health risk concerns, bacteriocins, either purified or excreted by bacteriocin producing strains, are a great alternative to the use of chemical preservatives in dairy products. Bacteriocins can be applied to dairy foods on a purified/crude form or as a bacteriocin-producing LAB as a part of fermentation process or as adjuvant culture. A number of applications of bacteriocins and bacteriocin-producing LAB have been reported to successful control pathogens in milk, yogurt, and cheeses. One of the more recent trends consists in the incorporation of bacteriocins, directly as purified or semi-purified form or in incorporation of bacteriocin-producing LAB into bioactive films and coatings, applied directly onto the food surfaces and packaging. This review is focused on recent developments and applications of bacteriocins and bacteriocin-producing LAB for reducing the microbiological spoilage and improve safety of dairy products.

Osman Gencel, Omer Karadag, Osman Hulusi Oren et al.

Abstract In this review, steel slag usage in the cement and concrete industry and its environmental effects were examined. Also, its physical and chemical structure, its effect on the characteristics of concrete, and its applications in different usage areas were specified. Within the scope of the study, literature was examined by reviewing investigations of steel slag usage in the cement and concrete industry. The content and results of these studies were assessed, and the intended effects of these by-products were presented. These factory by-products, whose storage and release into nature are quite inconvenient, are assessed at different sites around the world and regained to the sector. Thus the benefits of both economic and ecological balance were examined. As a result, opinions and recommendations were presented.

Yu Pei, Yingming Zhu, Suxia Liu et al.

Abstract The mechanism of the environmental regulations affecting carbon emissions is complex, and for many years it has been a hot research topic for researchers. However, few of the previous studies have focused on whether or not environmental regulations can potentially influence carbon emissions through technical efficiency. Therefore, the present study chose to investigate the mediation effects of the technical efficiencies between environmental regulations and carbon emissions using the provincial panel data of energy-intensive industries for the period ranging from 2005 to 2015. The results were as follows: (i) In regard to the entire group of energy-intensive industries, it was found that environmental regulations could not only potentially directly reduce carbon emissions, but also indirectly reduce carbon emissions through technical efficiency. In other words, technical efficiency had played a partial mediation role between the environmental regulations and the carbon emissions; (ii) It was observed that for the different subdivided energy-intensive industries, the different levels of technical efficiency had shown various mediation effects. For example, the mediation effects of technical efficiency in the petroleum processing and coking (PPC) industry; papermaking and paper products (PPP) industry, and raw chemical materials and chemical products (RCMCP) industry, were found to be similar to those of the whole energy-intensive industries. Furthermore, the “Porter Hypothesis” had been verified in the nonmetal mineral products (NMP) industry. However, there were no mediation effects observed in the smelting and pressing of ferrous metals (SPFM) and smelting and pressing of nonferrous metals (SPNM) industries; (iii) In this study, in accordance with the regression results of the double-threshold models, it was found that for the energy-intensive industries as a whole, the carbon emission reduction effects of environmental regulations had become stronger with the increases in technical efficiency. For the PPP and RCMCP industries, there was an inverted U-shaped relationship observed between environmental regulations and carbon emissions when the technical efficiency was taken as the threshold variable. Therefore, based on the research conclusions achieved in this study, some policy recommendations were put forward.

S. Walas

Patricia Reñones, Jose Campos-Martin, Silvia Morales-delaRosa

This work investigates the vapor-phase decarbonylation of furfural to furan, a key platform intermediate, using Pd/γ-Al₂O₃ catalysts under conditions approaching industrial operation. Reaction parameters, including space velocity, temperature, and pressure, were systematically optimized. Although lower pressures favor catalytic activity, a compromise pressure of 10 bar was selected to facilitate downstream separation. The optimal reaction temperature was identified as 325 °C, providing high activity and near-complete selectivity toward furan. Catalyst stability was enhanced through modification of the alumina support with K, Ca, and La cations. The unmodified, Ca-, and La-modified catalysts exhibited rapid deactivation within the first 24 h on stream, whereas the K-modified catalyst showed significantly improved stability with no clear deactivation over this period. At longer times on stream, gradual deactivation was observed, mainly attributed to coke deposition. The superior performance of the K-modified catalyst is associated with reduced acidity and slight modification of palladium electronic density and dispersion. Regeneration of severely deactivated catalysts proved challenging, resulting in poor catalytic recovery. Therefore, regeneration was performed while conversion remained above 90% and selectivity above 95% to maintain process operability. Long-term catalyst lifetime was demonstrated through multiple reaction–regeneration cycles, achieving at least 200 h on stream without significant loss of activity or selectivity for the optimal formulation.

Jiachen Li, Weitao Yang

We derive analytical expressions for chemical potentials within the random phase approximation (RPA), equivalently the $GW$ energy functional evaluated using non interacting Green's functions ($G_s$). The chemical potential is obtained using two formally equivalent approaches: a direct derivative of the total energy with respect to particle number, and a functional derivative via the chain rule through $G_s$, both validated with finite difference benchmarks. We show that the functional derivative of the $GW$ correlation energy$\unicode{x2013}$i.e., the $GW$ correlation self energy$\unicode{x2013}$exhibits a discontinuity at integer particle numbers with finite jumps. This resolves the apparent inconsistency between accurate $GW$ quasiparticle energies and the large delocalization errors observed in RPA total energies, as standard $GW$ self energies neglect this nonanalytic behavior. Our results suggest that derivative discontinuities are a fundamental feature of correlation energy functionals, analogous to the known discontinuity in the exact exchange correlation energy.

Logan Williams, Daniel Mikkelson, Aidan Rigby et al.

To decarbonize their industrial facilities, The Dow Chemical Company has collaborated with Idaho National Laboratory (INL) to study the integration of nuclear power with an industrial chemical facility. Using Holistic Energy and Resource Optimization Network developed at INL for optimizing and analyzing integrated energy systems, a nuclear microreactor system was sized and evaluated for dynamic dispatch to Dow Silicones Corporation’s Carrollton, KY (USA) site for siloxane production. It was found that a 180 MWth system (12 × 15MWth) with 75.1 MWhth of thermal energy storage could provide heat and power to the chemical facilities. In the process, this would reduce electricity imports by 99.9 % and reduce the Scope 1 and 2 emissions of the site by 292,100 tonnesCO2/yr (98.8 %). The primary novelty of this work is a first of a kind design and optimization of a microreactor powered integrated energy system to provide heat and power to a chemical plant using real plant data. This analysis will pave the way for future studies using dispatchable clean energy sources to reduce carbon emissions and commodity industries’ reliance on fossil fuels.

Rajeshwari Gangadharachar, Kusuma Manjunath, Jagannath Kesturu Venkatarayappa

Abstract We worked on the facile solution combustion reaction to obtain GdVO4 nanoparticles by using peroxovanadate gel for the first time as a precursor, gadolinium nitrate as an oxidizer, and tartaric acid as a fuel. The synthesized nanoparticles were used to investigate the photocatalytic activity against methylene blue dye and antimicrobial activity. The powder X-ray diffraction analysis reveals the generation of GdVO4 nanoparticles having a tetragonal phase with a crystallite size of ~ 18 nm. Scanning electron micrograph (SEM) images exhibit a porous environment of the product. Brunauer Emmett-Teller surface area analysis of GdVO4 nanoparticles indicates a relatively sizable specific surface area of ~ 44.5 m2g–1. Transmission electron microscopy exhibits a regular distribution of particles with a standard particle size varying in the range of 30–90 nm. The band gap of 2.5 eV is projected using the Ultraviolet DRS spectrum of GdVO4 nanoparticles. The photoluminescence spectrum unveils an emission peak at 470 nm. The environmental degradation of methylene blue (MB) dye using GdVO4 nanoparticles as a photocatalyst exhibits ~ 90% of decolorize in the presence of visible light radiation. Also, the inhibiting the growth of microorganism activity of GdVO4 nanoparticles was tested against E- coli, Streptococcus mutants, Aspergillus niger and Candida albicans and it was found to be possessing inhibiting property.