Hasil untuk "Chemical industries"

Walter G. Blacconiere, Dennis M. Patten

M. Poliakoff, J. M. Fitzpatrick, T. R. Farren et al.

A. Straathof, S. Panke, A. Schmid

L. Szente, J. Szejtli

C. Leonelli, T. Mason

Xiao Zhang, Hui Ni, Xiangming Xu et al.

The utilization of cellulose nanocrystals (CNCs), a renewable and eco-friendly nanomaterial, has emerged as the favored option for sustainable fillers. This paper presents diverse methods for CNCs preparation, including acid hydrolysis, oxidation, mechanical method, enzymatic hydrolysis, solvent method and hybrid approach. The strategies for modifying CNCs can be summarized as encompassing physical adsorption through non-covalent bond interactions and chemical modifications via covalent bonding. Moreover, the applications of CNCs in sensing systems, electronic skin devices, packaging materials, electronics industries, stabilizers and cosmetics are discussed with a particular emphasis on their contribution to enhancing polymer matrix properties. Lastly, future prospects for the advancement of CNCs are explored with a focus on its potential impact on sustainability efforts.

Michelle Weichelt, Larissa Wahl, Nahum Travitzky et al.

Porous ceramics have a wide range of applications regarding their exceptional structural and specific mechanical properties, such as adjustable permeability, high surface area, and high specific strength. To enhance the compressive strength of porous alumina further, core-shell structures with a dense core and porous shell were produced by combining co-extrusion and robocasting. Different amounts of spherical cellulose particles were added to the paste and subsequently burned out from the printed green bodies to obtain porous alumina. This leads to a porosity ranging from 18 % to 55 % in the samples, whereas the dense alumina shows a porosity of ∼2 %. Two different core-shell ratios were realized to investigate the influence of the dense core on the properties. The core-shell samples were characterized in terms of their porosity using the rule of mixture. The compressive strength of the fabricated structures was investigated and compared to the theoretical strength of porous samples without a dense core. The theoretical strength of porous reference samples was calculated using an empirical exponential expression. A novel approach to structurally reinforce highly porous ceramics was demonstrated by incorporating the dense core. With a porosity of 20 %, the core-shell structures have an average compressive strength of ∼850 MPa. The macrostructure and microstructure of the core-shell samples were investigated using SEM and µCT imaging. This leads to a lower failure of the structure under mechanical load and thus extends the range of possible applications.

D. Constable, C. Jiménez-González, R. K. Henderson

S. Lockie, Kristen Lyons, G. Lawrence et al.

Lien Ai Nguyen, Hua He, C. Pham-Huy

About more than half of the drugs currently in use are chiral compounds and near 90% of the last ones are marketed as racemates consisting of an equimolar mixture of two enantiomers. Although they have the same chemical structure, most isomers of chiral drugs exhibit marked differences in biological activities such as pharmacology, toxicology, pharmacokinetics, metabolism etc. Some mechanisms of these properties are also explained. Therefore, it is important to promote the chiral separation and analysis of racemic drugs in pharmaceutical industry as well as in clinic in order to eliminate the unwanted isomer from the preparation and to find an optimal treatment and a right therapeutic control for the patient. In this article, we review the nomenclature, pharmacology, toxicology, pharmacokinetics, metabolism etc of some usual chiral drugs as well as their mechanisms. Different techniques used for the chiral separation in pharmaceutical industry as well as in clinical analyses are also examined.

D. Braga, L. Maini, F. Grepioni

Qing Dou, Bin Luo, Xinghong Dai et al.

In the enhancement of Novel <i>Sorghum bicolor</i> × <i>S. propinquum</i> Hybrid utilization, optimal planting densities and silage methods remain elusive. This study assesses the effects of planting densities, cellulase (CE), <i>Lactobacillus buchneri</i> (LAB), and their combination (LC) on fermentation quality and bacterial diversity of the hybrid silage. The experiment was carried out in a completely random block design with four additives and five planting densities (M1, M2, M3, M4, M5) as follows (4 additives × 5 planting densities): a control group without additives (CK), a group treated with <i>Lactobacillus buchneri</i> (LAB), a group with cellulase (CE), and a group treated with a combination of LAB and CE (LC), maintaining triplicates per treatment. In this study, the additive treatment improved the fermentation quality of silage compared with the control. In the M2-LC group, the contents of crude protein (CP; 7.88%), ether extract (EE; 1.91%), and ash (7.76%) were the highest, while the pH (3.30) was the lowest. The water-soluble carbohydrate (WSC; 11.28%) content was the highest in the M3-CE group, the lactic acid (LA; 6.79%) content was the highest in the M4-CE group, and the acetic acid (AA; 7.71%) content was the highest in the M2-LAB group. Meanwhile, the neutral washing fiber (NDF; 53.17%) content was the lowest in the M5-CE group, the acid detergent fiber (ADF; 41.01%) content was the lowest in the M2-CE group, and the propionic acid (PA; 0.26%) content was the lowest in the M1-LAB group. Adding LC notably reduced bacterial diversity, boosted <i>Lentilactobacillus</i>, and curbed Proteobacteria. LAB and LC markedly improved amino acid metabolism over CE and CK. Conversely, beta-lactam resistance, flagellar assembly, and ascorbate/aldarate metabolism pathways were suppressed. In the future, we will explore a variety of additives and adjust the cutting height to improve its comprehensive quality, create an innovative path for silage production, promote the efficient use of agricultural resources, and provide high-quality feed for animal husbandry.

Anubha Agrawal, Manojkumar Ramteke

Polymer grade scheduling, maritime surveillance, e-food delivery, e-commerce, and military tactics necessitate multiple agents (e.g., extruders, speed boats, salesmen) capable of visiting (or completing) dynamically changing locations (or tasks) in minimum time and distance. This study proposes a novel methodology based on clustering and local heuristic-based evolutionary algorithms to address the dynamic traveling salesman problem (TSP) and the dynamic multi-salesman problem with multiple objectives. The proposed algorithm is evaluated on 11 benchmark TSP problems and large-scale problems with up to 10,000 instances. The results show the superior performance of the proposed methodology called the dynamic two-stage evolutionary algorithm as compared to the dynamic hybrid local search evolutionary algorithm. Furthermore, the algorithm's applicability is illustrated through various scenarios involving up to four salesmen and three objectives with dynamically changing locations. To demonstrate real-world relevance, a maritime surveillance problem employing a helideck monitoring system is solved, wherein the objective is to minimize the patrolling route while visiting faulty vessels that threaten marine vessels. This study provides a general framework of TSP which finds application in several sectors, including planning and scheduling in chemical and manufacturing industries, the defense sector, and the e-commerce sector. Finally, the results showcase the effectiveness of the proposed methodology in solving the dynamic multiobjective, and multiple salesmen problem, which represents a more generalized version of the TSP.

Zhigang Lei, Chengna Dai, Ji-qin Zhu et al.

Mingjing Yao, Chunmin Ma, Xin Bian et al.

Cardiovascular disease (CVD) has become the leading cause of death, and it is critical to develop new functional foods to prevent intravascular thrombosis, the key cause of CVD. Fermented soy-based food is a good choice because of its native fibrinolytic enzyme (FE) activity. In this study, a strain that can produce a new type of fibrinolytic enzyme was selected from Chinese Douchi and identified as <i>Bacillus licheniformis</i> SFD-Y5 by molecular biology experiments and physiological and biochemical experiments. Single factor experiments combined with statistical experiments, including Plackett–Burman experiment, steepest ascent experiment and RSM (Box–Behnken design), were used to optimize the fermentation of FE by <i>B. licheniformis</i> SFD-Y5. The final FE activity was 2434.45 ± 28.49 IU/mL under optimal conditions, which is the highest FE activity produced by wild <i>B. licheniformis</i> so far. Further studies showed that Y5 FE is a serine metalloproteinase with good stability at alkaline pHs (pH 8.0–11.0). The results of our study could lay a foundation for the future production, molecular modification and further application in functional foods of Y5 FE.

Annika Vaksmaa, Simon Guerrero-Cruz, Pooja Ghosh et al.

Advancements in chemical, medical, cosmetic, and plastic producing industries have improved agricultural yields, health and human life in general. As a negative consequence, a plethora of chemicals are intentionally and unintentionally released to terrestrial and aquatic environments with sometimes devastating effects for entire ecosystems. One mitigation strategy to counteract this pollution is bioremediation. Bioremediation is an umbrella term for biologically mediated processes during which an undesired compound is transformed, degraded, sequestered and/or entirely removed from the ecosystem. Organisms across all domains of life may mediate bioremediation; yet, fungi are particularly promising candidates. They possess metabolic capabilities to break down complex molecules which make fungi the ultimate degraders of recalcitrant organic matter in nature. Bioremediation by fungi, also termed mycoremediation, has been more frequently investigated in terrestrial than aquatic ecosystems, although fungi also thrive in lacustrine and marine environments. Here, we focus on mycoremediation of emerging pollutants in aquatic environments. In this context, we draw parallels between terrestrial and aquatic fungal taxa, and their role in mycoremediation. We discuss the ability of fungi to break-down (i) pesticides, (ii) pharmaceuticals and personal care products, (iii) plastics, both conventional types and (iv) bioplastics, and fungal role, (v) mitigation of heavy metal pollution. Furthermore, we (vi) discuss possible mycoremediation strategies in applied settings and highlight novel enzyme based mycoremediation strategies.

F. Fischler

S. Chakraborty, Huiguang Dai, Papri Bhattacharya et al.

R. Kroes

Yong Li, Yuanchun Huang, Xieyi Zhang

In this paper, an Ab-initio study was employed to study the properties of interfaces of Al₃Y|Al. The interface strength, shear strength, structural stability, electronic density, bonding characteristics, stacking fault energy, and plasticity were all investigated. The interface with the stacking style of ABab or CBAcba has the greatest interface strength. The Al₃Y(111)|Al(111) interface has the highest tensile stress of 13.39 GPa for rigid stretching; and 9.39 GPa for relaxation stretching. In the stretching process, the Al₃Y(111)|Al(111) interface is prone to break on the Al₃Y side. However, the Al₃Y(010)|Al(010) and Al₃Y(110)|Al(110) interface systems tend to fracture at the interface and Al side, respectively. Moreover, the differential charge density, electron localization function, and partial density of states (PDOS) demonstrate the newly formed chemical bonds at the interface, and the chemical bonds were formed by s-p or s-p-d hybrid orbitals. According to the Rice ratio and shear stress, these interfaces were found to be plastic and the Al₃Y(111)|Al(111) interface has the best plasticity. This is significant because the formed interfaces are all advanced structure materials, which can be potentially used in automobile and aeronautical fields, even in some special industries.