Hasil untuk "Chemical industries"

James H. Clark

J. DiMasi, R. Hansen, H. Grabowski et al.

Marios-Petros Kitsaras, Stella Stopkowicz

Quantum-chemical calculations often make use of point-group theory to exploit molecular symmetry, resulting in a reduction of the computational cost and in insights into the electronic structure. This exploitation is often limited to subgroups of $D_{2h}$ which are Abelian with real characters. Here, we extend the symmetry exploitation to Abelian point groups with complex characters. Such point groups are often encountered in calculations that involve finite magnetic fields, though their occurrence is not limited to these cases alone. We present the evaluation of integrals over symmetry-adapted orbitals using the double-coset decomposition, as well as the use of these symmetries in the contractions needed within post Hartree Fock calculations in the context of block tensors. Efficiency gains are discussed for four simple hydrocarbons that exhibit a complex Abelian point group in the presence of a magnetic field.

Animetu Rawlings, Grandeur Omogbeimhe Ogbaji-Pat

Nigeria's limited freshwater resources are at risk due to the discharge of wastewater from water-intensive industries, such as food processing, that does not comply with the regulations of the National Environmental Standards and Regulation Enforcement Agency (NESREA). This could significantly harm both the ecosystem and human health. This study aims to assess the physicochemical and biological properties of wastewater discharged from selected bakeries in Benin City, Nigeria, to determine compliance with NESREA standards and highlight potential environmental risks. Wastewater samples were randomly collected from five bakeries in Benin City and examined for their physicochemical and biological features. The findings indicated that, except for potential of Hydrogen (pH), total dissolved solids (TDS), chemical oxygen demand (COD), chloride (Cl⁻), Ammonium Nitrogen (NH₄N), and lead (Pb), all other parameters were within NESREA's permitted limits for food industry effluent discharge. The average pH value (5.9) was below the permitted range, but the average TDS (4754.2 mg/l), COD (1058.34 mg/l), NH₄N (3.068 mg/l), Cl (2984.86 mg/l), along with Pb (0.0724 mg/l) values are substantially over NESREA standards. These results show non-compliance with NESREA rules, stressing the necessity for regulatory entities to monitor the quality of bakery wastewater in the research region to guarantee high-quality effluent discharge.

Brandon K. Phan, Chiho Kim, Janhavi Nistane et al.

Polymer packaging plays a crucial role in food preservation but poses major challenges in recycling and environmental persistence. To address the need for sustainable, high-performance alternatives, we employed a polymer informatics workflow to identify single- and multi-layer drop-in replacements for polymer-based packaging materials. Machine learning (ML) models, trained on carefully curated polymer datasets, predicted eight key properties across a library of approximately 7.4 million ring-opening polymerization (ROP) polymers generated by virtual forward synthesis (VFS). Candidates were prioritized by the enthalpy of polymerization, a critical metric for chemical recyclability. This screening yielded thousands of promising candidates, demonstrating the feasibility of replacing diverse packaging architectures. We then experimentally validated poly(p-dioxanone) (poly-PDO), an existing ROP polymer whose barrier performance had not been previously reported. Validation showed that poly-PDO exhibits strong water barrier performance, mechanical and thermal properties consistent with predictions, and excellent chemical recyclability (95% monomer recovery), thereby meeting the design targets and underscoring its potential for sustainable packaging. These findings highlight the power of informatics-driven approaches to accelerate the discovery of sustainable polymers by uncovering opportunities in both existing and novel chemistries.

Daniel E. Rivas, Lorenzo Paoloni, Rebecca Boll et al.

Traditional x-ray photoelectron spectroscopy (XPS) relies upon a direct mapping between the photoelectron binding energies and the local chemical environment, which is well-characterized by an electrostatic partial charges model for systems in equilibrium. However, the extension of this technique to out-of-equilibrium systems has been hampered by the lack of x-ray sources capable of accessing multiple atomic sites with high spectral and temporal resolution, as well as the lack of simple theoretical procedures to interpret the observed signals. In this work we employ multi-site XPS with a narrowband femtosecond x-ray probe to unravel different ultrafast dissociation processes of a polyatomic molecule, fluoromethane (CH$_{3}$F). We show that XPS can follow the cleavage of both the C-F and C-H bonds in real time, despite these channels lying close in binding energy. Additionally, we apply the partial charges model to describe these dynamics, and verify this extension with both advanced ab-initio calculations and experimental data. These results enable the application of this technique to out-of-equilibrium systems of higher complexity, by correlating real-time information from multiple atomic sites and interpreting the measurements through a viable theoretical modelling.

N. Peters, B. Rogg

Shuang Li, Xiaofeng Yang, Shuai Yang et al.

Enzymes are protein molecules functioning as specialized catalysts for chemical reactions. They have contributed greatly to the traditional and modern chemical industry by improving existing processes. In this article, we first give a survey of representative industrial applications of enzymes, focusing on the technical applications, feed industry, food processing and cosmetic products. The recent important developments and applications of enzymes in industry are reviewed. Then large efforts are dedicated to the worldwide enzyme market from the demand and production perspectives. Special attention is laid on the Chinese enzyme market. Although enzyme applications are being developed in full swing, breakthroughs are needed to overcome their weaknesses in maintaining activities during the catalytic processes. Strategies of metagomic analysis, cell surface display technology and cell-free system might give valuable solutions in novel enzyme exploiting and enzyme engineering.

T. Gerven, A. Stankiewicz

R. Wijffels, M. Barbosa, M. Eppink

B. K. Park, A. Boobis, S. Clarke et al.

Leonardo da Costa Sousa, Shishir P. S. Chundawat, Venkatesh Balan et al.

Nathalie Nießer, Geralt Siebert

Recently, increased efforts have been made to explore the possibility of using glass panes as structural components, such as shear stiffeners. However, there are obstacles to the widespread use of these panes, even though they have proven their load-bearing capacity in structural systems (Haese 2013). The sudden failure of individual glass panes is a major concern because it can affect the overall structural safety. To better understand the causes of this unpredictable behaviour of glass façades, a numerical and physical sensor concept in the form of a hybrid digital twin will be developed. This involves both measurements of real load-bearing systems and simulations using numerical sensors. The two concepts will initially be developed independently, whereby the virtual model is approximated in a continuous process using measurements of the real structure. For this idea of the hybrid digital twin, a numerical sensor model is first presented in this article, which is also used for the evaluation of real sensors and thus serves as a basis for further investigation. The research project on the safety of glass façades in load-bearing structures is an important step towards improving the reliability and durability of such structures. The introduction of a hybrid digital twin will contribute to the development of an improved safety concept and the further establishment of these applications.

Mohammed El Hadi Attia Attia, Murshitha Shajahan, Muthu Manokar Athikesavan et al.

The impact of using TiO2 nano-coated basin and glass cover cooling at different concentrations of 0.1, 0.2, and 0.3% on Traditional Hemispherical Solar Still (THSS) was researched at El Oued City, Algeria. From the research output, it is found that by adding nano-coated basin at concentrations of 0.1, 0.2, and 0.3% in the HSS, the output distilled water of 4.07, 4.54, and 4.96 kg was obtained. The use of nano-coated basin at concentrations of 0.1, 0.2, and 0.3% with glass cooling in the HSS produced the output distilled water of 4.9, 5.47, and 6.12 kg, respectively. Furthermore, energy and exergy efficiencies are calculated. The diurnal energy efficiency obtained for the HSS with a nano-coated basin at concentrations of 0.1, 0.2, and 0.3% is found as 33.24, 37.61, and 41%, while the daily exergy efficiency is 2.52, 3.03, and 3.47%, respectively. Similarly, the daily energy efficiency obtained for the HSS with a nano-coated basin at concentrations of 0.1, 0.2, and 0.3% with glass cooling are found to be 40.34, 46 and 51%, while the daily exergy efficiency is 3.32, 4.07, and 4.71%, respectively.

Yijie Weng, Jianhao Wu, Tara Kelly et al.

Artificial Intelligence (AI) is fundamentally reshaping various industries by enhancing decision-making processes, optimizing operations, and unlocking new opportunities for innovation. This paper explores the applications of AI across four key sectors: healthcare, finance, manufacturing, and retail. Each section delves into the specific challenges faced by these industries, the AI technologies employed to address them, and the measurable impact on business outcomes and societal welfare. We also discuss the implications of AI integration, including ethical considerations, the future trajectory of AI development, and its potential to drive economic growth while posing challenges that need to be managed responsibly.

Ratna, B. Padhi

Piotr Cwiek, Patrick Wollny, Matthieu R. Lalanne et al.

The temperature and species concentration history experienced by the gas-borne nanoparticles during their evolution in the flame has a major impact on their size, morphology, composition, and crystallinity. In our recent work (Combust. Flame, 244 (2022) 112251), we have reported optical emission measurements of a Fe(CO)5-doped H2/O2/Ar fuel-lean (ɸ = 0.5) flame, revealing that the temperature of the early-formed nanoparticles exceeds the gas temperature by several hundred degrees, while the particle volume fraction increases sharply, followed by rapid disintegration in the reaction zone. This behavior, modeled by single particle Monte-Carlo simulations indicates involvement of heterogeneous reactive processes at the particle surface, such as particle reduction and oxidation, growth and etching. Within the refined approach of the current study, reactive and non-reactive collisions were treated consistently, assuming rapid thermalization between the impinging molecule and the particle, with subsequent random energy sampling to determine reactivity. In the present work, we test the limits and validity of the heterogeneous flame-particle interaction model by manipulating the oxidation–reduction and growth-etching balance by varying the equivalence ratio (0.25<ɸ<1.5). For the entire range of equivalence ratios studied in experiments and simulations, we find a deviation between the particle and gas phase temperatures with significantly higher particle temperature, which is continued until a full degree of iron oxidation within the particle (O/Fe ratio=3/2) is reached. Validating the simulations against the measurements of particle temperature and volume fraction over a wide range of equivalence ratios, emphasized the necessity to account for gas-phase Fe-atom concentration depletion. We incorporated nucleation theory to estimate initial cluster population, linking Fe-concentration variation in the gas phase and the stochastic particle evolution model. The surface reaction parameters in our current work were updated using density functional theory literature data, and validation of the model predictions against experimental data, across the entire range of equivalence ratios.

Kaname Yoshida, Atsushi Nakahira

The spatial resolution of transmission electron microscopes (TEMs) and scanning transmission electron microscopes (STEMs) has been drastically improved by introducing aberration correction. However, observable range in electron sensitive zeolites are still limited due to electron irradiation damages. Nevertheless, atomic resolution imaging of some zeolites is currently being realized by various developments in electron microscopic hardware, such as high sensitivity cameras. On the other hand, surveying the status of TEM and STEM imaging is very important for further progress in the structural analysis of zeolites. Here, we demonstrate and compare the high-resolution imaging of zeolites with several kinds of imaging modes.

Yang Li, Yuchang Qing, Yuerui Zhang et al.

Single Ti3C2Tx MXene (MTO) materials are not suitable for electromagnetic (EM) wave absorption due to their high conductivity and impedance mismatch. To address this issue, we ingeniously took advantage of easily oxidized characteristics of Ti3C2Tx MXene to establish structural defects and multiphase engineering in accordion-like TixO2x−1 derived from Ti3C2Tx MXene by a high-temperature hydrogen reduction process for the first time. Phase evolution sequences are revealed to be Ti3C2Tx MXene/anatase TiO2 → Ti3C2Tx MXene/rutile TiO2 → TixO2x−1 (1 ≤ x ≤ 4) during a hydrogen reduction reaction. Benefiting from conductance loss caused by hole motion under the action of an external electric field and heterointerfaces caused by interfacial polarization, the impedance match and EM attenuation capability of accordion-like TixO2x−1 absorbers derived from Ti3C2Tx MXene are superior to that of pristine Ti3C2Tx MXene/TiO2 materials. Additionally, simulated whole radar cross section (RCS) plots in different incident angular of the Ti3C2Tx MXene/rutile TiO2 product are lower than −20 dBm2, and the minimum RCS value can reach −43 dBm2, implying a great potential for practical applications in the EM wave absorption. Moreover, the relationship among charges, defects, interfaces, and EM performances in the accordion-like TixO2x−1 materials is systematically clarified by the energy band theory, which is suitable for the research of other MXene-derived semiconductor absorbing composites.

Min-Jin Lim, Kaliyan Barathikannan, Ye-Jin Jeong et al.

The escalating global incidence of obesity and chronic diet-related disorders, such as type 2 diabetes, hypertension, cardiovascular disease, malignancies, and celiac disease, has intensified the focus on dietary factors and disease risks. Rice, a dietary staple for billions, is under scrutiny, particularly polished or white rice, which is high in starch and in the glycemic index and low in nutrition due to the removal of the outer bran layer during milling. This study critically analyzes the comparison between whole brown rice (BR) and milled white rice in terms of health benefits. A significant finding is the enhancement of food nutrition through fermentation, which improves protein digestibility and mineral availability and releases peptides and amino acids. The study also highlights the increased antibacterial and antioxidant activity of foods, including health benefits, through fermentation. A comprehensive review of existing data on the nutritional content and health advantages of whole fermented BR grains is presented, alongside experiments in developing fermented BR-based foods. The safety, preservation, and the economic and environmental advantages of consuming regularly fermented BR instead of white or unfermented BR are discussed. Finally, the paper addresses the commercialization challenges and future opportunities for promoting fermented BR as a healthier food alternative.