Hasil untuk "Chemical technology"

Ayyappan M, Muthiah A

In this paper, melting and solidification characteristics of composite PCM filled inside the shell and tube heat exchanger were investigated experimentally. ZnO nanoparticles (NPs) were synthesized using the sol–gel method. Myristic acid (MA) considered as the pure PCM and ZnO NPs serving as the supporting material. The morphology and crystal structure of ZnO particles were analyzed using Field Emission Scanning Electron Microscopy (FESEM) and x-ray Diffraction (XRD) techniques. ZnO nanoparticles at concentrations of 0.1, 0.3, and 0.5 wt% were individually dispersed in myristic acid to evaluate the heat transfer characteristics of nanocomposite phase change materials (NCPCMs) through phase change processes. Differential Scanning Calorimetry (DSC) analyses were used to assess the phase change behavior of PCM and nanocomposite PCMs in liquid and solid states. The phase change characteristics of the Myristic acid and nanocomposite PCMs were probed with regard to heat exchanger studies. The results show significant time savings, with a 68.04% reduction in complete melting time and a 42.73% reduction in solidification time when using 0.5 wt% ZnO NPs at a mass flow rate of 5 l min ^−1 . Furthermore, incorporating ZnO NPs at concentrations of 0.1, 0.3, and 0.5 wt% enhanced the thermal conductivity of the NCPCMs by 36.41%, 62.96%, and 82.71%, respectively, compared to pure MA.

Cong Shen, Meina Wu, Minxuan Su et al.

Abstract Background The emergence of plasmid-mediated colistin resistance, primarily driven by the mcr-1 gene, represents a major global health threat. IncI2 plasmids, one of the leading carriers of mcr-1, have been frequently recovered from clinical and agricultural settings. However, their persistence in the absence of antibiotic pressure and adaptive responses to colistin exposure remain poorly understood. Methods We conducted 60-day laboratory evolution experiments using Escherichia coli C600 carrying the mcr-1-harboring IncI2 plasmid pBD110 under three colistin concentrations (0, 2, and 4 mg/L). Stability was evaluated using polymerase chain reaction (PCR). Bacterial fitness was assessed using growth curve analysis and competition assays. Antimicrobial susceptibility was determined by the broth microdilution method. Conjugation potential was examined using conjugation experiments. Genomic alterations were investigated using whole-genome sequencing combined with bioinformatic analysis. Results pBD110 was stably maintained for 120 passages under all conditions, with no significant loss observed in the absence of colistin. Under strong selection (4 mg/L), plasmid abundance increased, whereas moderate pressure (2 mg/L) led to fitness costs and reduced plasmid copy number. Whole-genome sequencing revealed distinct adaptive strategies: plasmids under non-selective conditions accumulated mutations in conjugation-related genes, enhancing transfer frequency, whereas those under colistin exposure retained structural stability but acquired shufflon inversions that impaired conjugation. Host genomes accumulated numerous chromosomal mutations, particularly in metabolic and stress response pathways, to compensate for resistance-associated burdens. Conclusions IncI2 plasmids exhibit dual evolutionary strategies. In the absence of colistin, they optimized horizontal transfer, whereas under selective pressure, they prioritized the stability and vertical inheritance of mcr-1. These findings provide new insights into the persistence and dissemination of colistin resistance and highlight evolutionary trade-offs that shape plasmid-host coadaptation.

Anjana Barange, Meitram Niraj Luwang, Santosh Kumar Meena

Ruizhe Zhang, Qingcui Wang, Shuanping Du

Propeller noise is the main source of ship-radiated noise. Extracting and analyzing the modulation characteristics from the propeller noise plays a crucial role in classifying and identifying vessel targets. Existing demodulation methods such as Detection of Envelope Modulation On Noise (DEMON), narrowband demodulation, and cyclostationary analysis can be used to extract modulation features. However, capturing the modulation features on the envelope spectrum may be hard under low signal-to-noise ratio scenarios, since the envelope spectrum is contaminated by interference noise. To address this challenge, selecting an optimal frequency band rich in modulation information can significantly enhance demodulation performance. This paper proposes an Adaptive Hoyer-L-moment Envelope Spectrum (AHLES) method. The method first introduces an optimal frequency band selection method based on the golden section search strategy. A Hoyer-L-moment metric is then designed to quantify the modulation intensity within narrow frequency bands. Based on this metric, the optimal spectral coherence integration band is adaptively selected according to the signal’s inherent modulation characteristics, thereby enhancing demodulation performance. The effectiveness of the proposed method is validated through experiments on both simulated signals and merchant ship data.

Tiantian Zhao, Guowan Su, Lijun Zhang et al.

Abstract Food‐derived peptides have garnered significant attention in research due to their multifaceted functionalities, abundant availability, efficient utilization of agricultural by‐products, and environmentally sustainable preparation methods. These peptides play a crucial role in human health, yet their precise mechanisms of action remain largely unexplored, posing challenges in their screening, preparation, and effective application utilizing protein‐based raw materials. This review offers an extensive examination of 19 types of bioactive peptides derived from food. The sources of food‐derived bioactive peptides are well concluded and the classifications are made according to their potential health benefit based on five primary systems: general bodily functions, the nervous system, the cardiovascular system, the metabolic system, and the immune system. This review specifically highlights the multifaceted impacts of tasty peptides on human health, extending beyond their gustatory effects. Furthermore, it explores the interplay between various functions of bioactive peptides, noting a progression from basic to advanced functionalities. Antioxidant activity and the modulation of key enzymes are identified as fundamental actions that are interconnected with other functional properties. This implies that a single bioactive peptide could exhibit multiple beneficial effects. The key role of antioxidant capabilities is underscored based on their broad influence and straightforward assessment. This comprehensive analysis aims to deepen the systematic understanding of the diverse benefits offered by various food‐derived peptides.

Fayomi Omotola Michael, Olasan Joseph Olalekan, Aguoru Celestine Uzoma et al.

Aim. This study was purposed to investigate the effects of zinc oxide nanoparticles (ZnO NPs) on the growth and yield performance of two soybean (Glycine max L.) varieties, TGX1904-6F and TGX1951-3F, under controlled experimental conditions. Methods. Zinc oxide nanoparticles were synthesized and characterized following standard protocols, and their effects were evaluated across five treatment levels (20, 40, 60, 80, and 100 ppm) in a completely randomized design with five replicates. Growth parameters, including plant height, leaf morphology, stem diameter, and branch number, were assessed alongside phenological and yield traits such as days to flowering, flower production, pod metrics, and seed weights. The results revealed significant improvements in plant growth and yield metrics at intermediate ZnO NP concentrations, with enhancements observed in plant height, branch number, pod weight, and seed yield. Specifically, 60 ppm ZnO NP treatment resulted in the highest branch production, while 40 and 80 ppm treatments significantly promoted floral and pod development. Conversely, higher concentrations (100 ppm) exhibited inhibitory effects on plant height and leaf morphology, suggesting potential toxicity at elevated ZnO NP levels. Statistical analyses, including one-way ANOVA and Pearson’s correlation, confirmed significant treatment effects (P ≤ 0.05) on growth and yield parameters, highlighting the critical role of dose optimization. Conclusions. The findings underscore the potential of ZnO NPs as a novel agricultural supplement to enhance soybean productivity while emphasizing the need for balanced application to mitigate toxicity risks. This study contributes valuable insights into sustainable farming practices, leveraging nanotechnology to optimize crop performance and address global food security challenges.

Philipp Lotz, Marcus Petermann, Andreas Kilzer

Cells of spent brewer's yeast represent a natural and sustainable material for the encapsulation of aroma compounds. Although the usability of yeast cells as microcapsules was proven decades ago, respective technologies are not established in the market. The conventional production method involves the suspension of yeast and aroma oil in water. Resulting mixtures have a poor processability, which likely contributes to the lack of industrial interest. Production of flavour filled cells without the suspension step is possible using the concentrated powder form technology. In the given work, this high-pressure spraying process was used to fabricate a dry powder of yeast cells containing 15 wt% limonene. The release behaviour in different model matrices was investigated to predict the applicability in food products. Immediate or prolonged release was observed depending on the media composition. Water was confirmed as the main release trigger. The fabricated yeast capsules can serve as a controlled release system.

Zhiwei Zhang, Dawei Pan, Yan Liang et al.

Field determination and ecological risk assessment of dissolved lead (Pb) were performed at two Yellow Sea sites in China using a continuous automated electrochemical system (CAEDS). This CAEDS instrument includes an automatic triple filter sampler and an electrochemical detection water quality analyzer, which might be operated automatically four times daily. The dissolved Pb concentrations varied from 0.29 to 1.57 μg/L in the South Yellow Sea over 16 days and from 0.32 to 2.28 μg/L in the North Yellow Sea over 13 days. During the typhoon and algal bloom periods, the Pb concentration was as high as ten times greater than usual. According to the calculation of contamination factors (C_f) and subsequent analysis, seawater quality was classified as Grade II. Through species sensitivity distribution (SSD) method experiments and ecological risk analysis, an average risk quotient (RQ) below 1 for both areas was obtained, indicating a low-to-moderate ecological risk. This system will be helpful for Pb monitoring and assessment in seawater and contribute to the biogeochemical cycling study of Pb.

Roman Lepikash, Daria Lavrova, Devard Stom et al.

Environmental pollution is becoming ubiquitous; it has a negative impact on ecosystem diversity and worsens the quality of human life. This review discusses the possibility of applying the plant microbial fuel cells (PMFCs) technology for concurrent processes of electricity generation and the purification of water and soil ecosystems from organic pollutants, particularly from synthetic surfactants and heavy metals. The review describes PMFCs’ functioning mechanisms and highlights the issues of PMFCs’ environmental application. Generally, this work summarizes different approaches to PMFC development and to the potential usage of such hybrid bioelectrochemical systems for environmental protection.

Viktória Hideg, Emese Makó

In recent years an increasing number of cities and transport planning documents (such as Sustainable Urban Mobility Plan) aim to reduce car traffic and promote active modes of transport – walking and cycling. The development of active modes of transport is increasingly becoming a focus of urban planning. However, detailed information on the needs of pedestrians and aspects of the assessment of a pedestrian-friendly environment are usually not available. In most cases, the only indicator of the effectiveness of improvements is the modal split and the rate of pedestrians. An objective assessment method is needed to help identify areas that need to be developed for walking. The various planning regulations and legislation provide a framework for the design of pedestrian infrastructure, but many aspects that make public spaces attractive and pedestrian-friendly (green spaces, aesthetics, sense of safety, etc.) are not included in the regulations. This problem can be addressed by the walkability index, which can provide an objective, data-based measure of how pedestrian-friendly an area is. It can also be a tool for analysing and monitoring. It can show areas where walking conditions are inadequate and intervention is needed. Regularly carrying out the survey can also serve to analyse the impact of measures taken in the meantime. This article describes the methodology and application of the walkability index.

Junqiang Yang, Yanyan Deng, Min Zhang et al.

Obesity is one of the foremost public health concerns. Human pancreatic lipase (hPL), a crucial digestive enzyme responsible for the digestion of dietary lipids in humans, has been validated as an important therapeutic target for preventing and treating obesity. The serial dilution technique is commonly used to generate solutions with different concentrations and can be easily modified for drug screening. Conventional serial gradient dilution is often performed with tedious multiple manual pipetting steps, where it is difficult to precisely control fluidic volumes at low microliter levels. Herein, we presented a microfluidic SlipChip that enabled formation and manipulation of serial dilution array in an instrument-free manner. With simple slipping steps, the compound solution could be diluted to seven gradients with the dilution ratio of 1:1 and co-incubated with the enzyme (hPL)-substrate system for screening the anti-hPL potentials. To ensure complete mixing of solution and diluent during continuous dilution, we established a numerical simulation model and conducted an ink mixing experiment to determine the mixing time. Furthermore, we also demonstrated the serial dilution ability of the proposed SlipChip using standard fluorescent dye. As a proof of concept, we tested this microfluidic SlipChip using one marketed anti-obesity drug (Orlistat) and two natural products (1,2,3,4,6-penta-O-galloyl-β-D-glucopyranose (PGG) and sciadopitysin) with anti-hPL potentials. The IC₅₀ values of these agents were calculated as 11.69 nM, 8.22 nM and 0.80 μM, for Orlistat, PGG and sciadopitysin, respectively, which were consistent with the results obtained by conventional biochemical assay.

Björn Sjöstrand, Carl-Anton Karlsson, Christophe Barbier et al.

Understanding cellulose hornification provides crucial information regarding drying of pulp, paper, and other cellulosic materials as well as recycling them. By measuring drainage, fiber width, and water retention value of hardwood and softwood pulps before and after sheet forming and after different drying procedures at different achieved levels of solids, the hornification was evaluated. The water retention value was also measured for the pulps when dried from acetone to observe what happens when hydrogen bonds are not available in the liquid phase. The drainage and fiber width decreased with increasing solids content; the fibers became increasingly stiff with increased water removal. Water retention measurements indicated that hornification is a stepwise process with large drops in fiber flexibility as soon as the fibers are being processed and later after a certain amount of water has been removed. In sum, the fibers must achieve a certain solids content to show hornification, and hydrogen bonds in water draw the cellulose surfaces together to create hornification. The mechanism of hornification is believed to be driven by hydrogen bonds and related to the distance between cellulose chains inside the fiber wall. Other types of bonds are probably also present and help with the irreversibility of hornification.

Bingxin Liu, Yulong Du, Chengyu Liu et al.

Thermal infrared hyperspectral imager is one of the frontier payloads in current hyperspectral remote sensing research. It has broad application prospects in land and ocean temperature inversion, environmental monitoring, and other fields. However, due to the influence of the production process of the infrared focal plane array and the characteristics of the material itself, the infrared focal plane array inevitably has blind pixels, resulting in spectral distortion of the data or even invalid data, which limits the application of thermal infrared hyperspectral data. Most of the current blind pixels detection methods are based on the spatial dimension of the image, that is, processing single-band area images. The push-broom thermal infrared hyperspectral imager works completely different from the conventional area array thermal imager, and only one row of data is obtained per scan. Therefore, the current method cannot be directly applied to blind pixels detection of push-broom thermal infrared hyperspectral imagers. Based on the imaging principle of push-broom thermal infrared hyperspectral imager, we propose a practical blind pixels detection method. The method consists of two stages to detect and repair four common types of blind pixels: dead pixel, dark current pixel, blinking pixel, and noise pixel. In the first stage, dead pixels and dark current pixels with a low spectral response rate are detected by spectral filter detection; noise pixels are detected by spatial noise detection; and dark current pixels with a negative response slope are detected by response slope detection. In the second stage, according to the random appearance of blinking pixels, spectral filter detection is used to detect and repair spectral anomalies caused by blinking pixels line by line. In order to verify the effectiveness of the proposed method, a flight test was carried out, using the Airborne Thermal-infrared Hyperspectral Imaging System (ATHIS), the latest thermal infrared imager in China, for data acquisition. The results show that the method proposed in this paper can accurately detect and repair blind pixel, thus effectively eliminating spectral anomalies and significantly improving image quality.

Zhenzhen Liu, Yan Liu, Hongfu Zuo et al.

Lubricating oil monitoring technology is a commonly used method in aeroengine condition monitoring, which includes particle counting technology, as well as spectral and ferrography technology in offline monitoring. However, these technologies only analyze the characteristics of wear particles and rely on physical and chemical analysis techniques to monitor the oil quality. In order to further advance offline monitoring technology, this paper explores the potential role of differences in wear particle kinematic characteristics in recognizing changes in wear particle diameter and oil viscosity. Firstly, a kinematic force analysis of the wear particles in the microfluid was carried out. Accordingly, a microfluidic channel conducive to observing the movement characteristics of particles was designed. Then, the wear particle kinematic analysis system (WKAS) was designed and fabricated. Secondly, a real-time tracking velocity measurement algorithm was developed by using the Gaussian mixture model (GMM) and the blob-tracking algorithm. Lastly, the WKAS was applied to a pin–disc tester, and the experimental results show that there is a corresponding relationship between the velocity of the particles and their diameter and the oil viscosity. Therefore, WKAS provides a new research idea for intelligent aeroengine lubricating oil monitoring technology. Future work is needed to establish a quantitative relationship between wear particle velocity and particle diameter, density, and oil viscosity.

Junping Hu, Youxing Liu

Exploiting non-noble metals catalysts with excellent performance for hydrogen evolution reaction (HER) has aroused gigantic interest, but still challenges. Herein, we reported the graphene oxide (GO) supported Fe doped Ni(OH) _2 hexagonal nanosheets (GO-Fe,Ni HHNs) for HER firstly. SEM and XRD were carried out to investigate the morphology and crystal structure of the GO-Fe,Ni HHNs systematically. The elements and bonding of the sample were measured via using XPS. In addition, we found that the recrystallization treatment could significantly improve the morphology and crystallinity of the nanosheets. Most important, the GO-Fe,Ni HHNs possessed exceptional catalytic performance and stability in PBS solution. The overpotential (10 mA cm ^−2 ) and Tafel slope were 190 mV and 110 mV dec ^−1 , respectively, significantly better than that of other non-noble metal catalysts reported before.

Cláudia P. Passos, Rita M. Costa, Sónia S. Ferreira et al.

Coffee brews have High Molecular Weight (HMW) compounds with described immunostimulatory activity, namely polysaccharides and melanoidins. Melanoidins are formed during roasting and are modified during brews technological processing. In addition, brews have Low Molecular Weight (LMW) compounds, namely free chlorogenic acids and caffeine, with well-known anti-inflammatory properties. However, this study shows that both espresso and instant coffee brews did not present immunostimulatory neither anti-inflammatory in vitro activities. It is possible that the simultaneous existence of compounds with antagonistic effects can mitigate their individual effects. To test this hypothesis, an ultrafiltration separation process was applied, studying the behavior of coffee brews’ HMW on retention of LMW compounds. Several ultrafiltration sequential cycles were required to separate retentates from LMW compounds, suggesting their retention. This effect was higher in instant coffee, attributed to its initial higher carbohydrate content when compared to espresso. Separation of HMW and LMW compounds boosted their immunostimulatory (6.2–7.8 µM nitrites) and anti-inflammatory (LPS induced nitrite production decrease by 36–31%) in vitro activities, respectively. As coffee anti-inflammatory compounds are expected to be first absorbed during digestion, a potential in vivo fractionation of LMW and HMW compounds can promote health relevant effects after coffee intake.

Alejandra Rodríguez, Teresa Gea, Xavier Font

Biosurfactants are being proposed as a substitute for surfactants in the framework of a circular economy strategy. Sophorolipids (SL) are a type of biosurfactant produced by yeast that can be produced through submerged or solid-state fermentation (SSF) processes. Even though sophorolipids are being produced at full scale, through submerged fermentations, environmental and technoeconomic information regarding its production through SSF is unavailable. An inventory of data necessary to perform preliminary economic and environmental assessments is presented in this study. Data was obtained from three SSF processes at 22-L reactor volume and from two SSF processes at 100-L reactor volume, using winterization oil cake and molasses as substrates, wheat straw as support material, and Starmerella bombicola as SL producing yeast. The effect of increasing the operation scale was assessed. Besides presenting parameters such as inoculum production, initial mass of substrates, and airflow requirements; process emissions (NH3, Volatile Organic Compounds, N2O, SH2 and CH4) and the biogas potential of the spent fermentation solids were also presented.

Gorjanc Dunja Šajn, Bras Ana, Novak Boštjan

Nonwovens represent a part of technical textiles that are used for clothing (“cloth tech”). Nonwovens are also used in the footwear industry mainly for functional purposes, where the aesthetic properties are not of great importance. They are mainly used for support and reinforcement of footwear. All three groups of textiles are used for footwear, i.e. woven fabrics, knitted fabrics and nonwovens that are produced directly from fibres, yarns or threads mainly from chemical fibres and in a small proportion from natural fibres.

Yu Yang, Li Wang, Li Wang et al.

Non-invasive tracking for monitoring the selective delivery and transplantation of biotargeted agents in vivo has been employed as one of the most effective tools in the field of nanomedicine. Different nanoprobes have been developed and applied to bioimaging tissues and the treatment of diseases ranging from inflammatory and cardiovascular diseases to cancer. Herein, we will review the recent advances in the development of optics-responsive nanomaterials, including organic and inorganic nanoparticles, for multimodal bioimaging and targeted therapy. The main focus is placed on nanoprobe fabrication, mechanistic illustrations, and diagnostic, or therapeutical applications. These nanomedicine strategies have promoted a better understanding of the biological events underlying diverse disease etiologies, thereby facilitating diagnosis, illness evaluation, therapeutic effect, and drug discovery.

Gorgels Theo GMF, van der Spek Peter J, Verkerk Annemieke JMH et al.

<p>Abstract</p> <p>Background</p> <p>To determine level, variability and functional annotation of gene expression of the human retinal pigment epithelium (RPE), the key tissue involved in retinal diseases like age-related macular degeneration and retinitis pigmentosa. Macular RPE cells from six selected healthy human donor eyes (aged 63–78 years) were laser dissected and used for 22k microarray studies (Agilent technologies). Data were analyzed with Rosetta Resolver, the web tool DAVID and Ingenuity software.</p> <p>Results</p> <p>In total, we identified 19,746 array entries with significant expression in the RPE. Gene expression was analyzed according to expression levels, interindividual variability and functionality. A group of highly (n = 2,194) expressed RPE genes showed an overrepresentation of genes of the oxidative phosphorylation, ATP synthesis and ribosome pathways. In the group of moderately expressed genes (n = 8,776) genes of the phosphatidylinositol signaling system and aminosugars metabolism were overrepresented. As expected, the top 10 percent (n = 2,194) of genes with the highest interindividual differences in expression showed functional overrepresentation of the complement cascade, essential in inflammation in age-related macular degeneration, and other signaling pathways. Surprisingly, this same category also includes the genes involved in Bruch's membrane (BM) composition. Among the top 10 percent of genes with low interindividual differences, there was an overrepresentation of genes involved in local glycosaminoglycan turnover.</p> <p>Conclusion</p> <p>Our study expands current knowledge of the RPE transcriptome by assigning new genes, and adding data about expression level and interindividual variation. Functional annotation suggests that the RPE has high levels of protein synthesis, strong energy demands, and is exposed to high levels of oxidative stress and a variable degree of inflammation. Our data sheds new light on the molecular composition of BM, adjacent to the RPE, and is useful for candidate retinal disease gene identification or gene dose-dependent therapeutic studies.</p>