Hasil untuk "Chemical technology"

J. Rumble, D. Bickham, C. Powell

F. Kollmann, W. Cǒté

H. Craighead

L. Szente, J. Szejtli

Revathy Sankaran, Ricardo Andres Parra Cruz, Harshini Pakalapati et al.

Microalgal and lignocellulosic biomass is the most sumptuous renewable bioresource raw material existing on earth. Recently, the bioconversion of biomass into biofuels have received significant attention replacing fossil fuels. Pretreatment of biomass is a critical process in the conversion due to the nature and structure of the biomass cell wall that is complex. Although green technologies for biofuel production are advancing, the productivity and yield from these techniques are low. Over the past years, various pretreatment techniques have been developed and successfully employed to improve the technology. This paper presents an in-depth review of the recent advancement of pretreatment methods focusing on microalgal and lignocellulosic biomass. The technological approaches involving physical, chemical, biological and other latest pretreatment methods are reviewed.

A. G. Akerdi, S. Bahrami

Abstract Advanced oxidation processes (AOPs) introduce a hopeful technology for the removal of water polluted with hard degradable organic compounds. Today, one of the main effective AOP technologies to degrade these hazardous organics is via the photocatalytic process. The present review focuses on the recent progress in the fixed-bed and immobilized nanophotocatalysts and also their applications for resolving the environmental concerns. Various organics elimination using a variety of photocatalysts and innovative reactors are discussed. This critical review summarizes the recent progress in the synthesis and modification (physical and chemical) of semiconductors. Furthermore, different ways of photocatalysts immobilization are explained in details. By considering different dangerous chemicals present in wastewater and different industries, catalytic methods used by researchers to degrade these organic compounds are reviewed. In addition, the degradation pathway of some organics through the catalytic operation is described.

��ngela Anglada, A. Urtiaga, I. Ortiz

Sunho Jeong, Young-Geun Ha, Jooho Moon et al.

N. Brosse, A. Dufour, Xianzhi Meng et al.

Anthony Chidi Ezika, Williams Kehinde Kupolati, Emmanuel Rotimi Sadiku et al.

The current challenge in energy storage technologies lies in identifying efficient electrode materials for Magnesium-ion (Mg-ion) batteries, motivating the exploration of the energy storage capabilities of Polypyrrole-MXene (Ti2CO2) nanocomposites as a potential solution to enhance battery performance. Hence, in this paper, quantum mechanical simulations were employed to examine the capability of energy storage of Polypyrrole-MXene (Ti2CO2) filled nanocomposite. The electronic structures, adsorption energies, and adsorption site of Mg@PPy/MXene (Ti2CO2) nanocomposite were investigated. The results reveal that Mg-ions on MXene/PPy nanocomposite have a very high adsorption energy of -0.84 eV. The distance of Mg-ion adsorption from the MXene’s surface at the bridge site is 2.75 Å. However, its distance from the PPy is considerably farther at 2.83 Å. The electron difference study, using the charge transfer analysis, revealed that physisorption is the dominating adsorption mechanism for the Mg-ion in the system. The electrode's propensity to transport electrons during the electrochemical reaction is shown by the projected density of state (PDOS), and its energy bandgap is 0.05. Consequently, the MXene (Ti2CO2) /PPy nanocomposite might be used as an Mg-ion electrode in battery applications.

Nga Thi Nguyen, Thanh Thi Ngoc Nguyen, Hue Thi Nguyen

Breast cancer remains a leading cause of mortality among women worldwide. In Vietnam, the rising incidence underscores the urgent need for early diagnostic markers. Genetic factors, particularly Single Nucleotide Polymorphisms (SNPs), play a critical role in breast cancer susceptibility. The SNP rs34678647, located downstream of the miR-221/222 cluster targeting Estrogen Receptor alpha (ERα), is hypothesized to influence breast cancer risk by modulating cancer-related pathways. This study investigates the association between rs34678647 and breast cancer risk in the Vietnamese population. A total of 234 DNA samples, comprising 131 breast cancer cases and 103 healthy controls, were genotyped using the Polymerase Chain Reaction-High Resolution Melting (PCR-HRM) technique, which is selected for its high sensitivity and specificity in SNP detection. Genotype frequencies were determined, and statistical analyses were conducted to evaluate associations. The PCR-HRM method successfully genotyped rs34678647 with high accuracy. The T allele was observed in 23% of cases and 19% of controls; however, no significant association with breast cancer risk was identified (OR = 1.19, 95% CI: 0.77-1.85, p = 0.43). Genotype distributions conformed to the Hardy-Weinberg equilibrium in both groups, supporting the representativeness of the sample. In conclusion, while the T allele of rs34678647 showed a nonsignificant trend toward increased breast cancer risk among Vietnamese women, the results were not statistically conclusive. These findings highlight the need for larger-scale studies to further explore the potential role of rs34678647 as a genetic risk factor and its applicability as an early diagnostic biomarker.

Lele Zheng, Yang Cao, Masatoshi Yoshikawa et al.

Federated learning (FL) enables collaborative model training across multiple institutions without the sharing of raw patient data, making it particularly suitable for smart healthcare applications. However, recent studies revealed that merely sharing gradients provides a false sense of security, as private information can still be inferred through gradient inversion attacks (GIAs). While differential privacy (DP) provides provable privacy guarantees, traditional DP methods apply uniform protection, leading to excessive protection for low-sensitivity data and insufficient protection for high-sensitivity data, which degrades model performance and increases privacy risks. This paper proposes a new privacy notion, sensitivity-aware differential privacy, to better balance model performance and privacy protection. Our idea is that the sensitivity of each data sample can be objectively measured using real-world attacks. To implement this new notion, we develop the corresponding defense mechanism that adjusts privacy protection levels based on the variation in the privacy leakage risks of gradient inversion attacks. Furthermore, the method extends naturally to multi-attack scenarios. Extensive experiments on real-world medical imaging datasets demonstrate that, under equivalent privacy risk, our method achieves an average performance improvement of 13.5% over state-of-the-art methods.

Adel Beig Babaei, Arash Dara, Hanieh Sadat Taheri

This study examines the effectiveness of a composite material made from reduced graphene oxide (rGO) and magnetic nanoparticles for the adsorption of heavy metals from wastewater, addressing a critical environmental issue as heavy metal pollution poses significant risks to human health. Traditional water treatment methods often fail to adequately remove these persistent contaminants. The composite takes advantage of graphene's high surface area and adsorption capacity, while the magnetic nanoparticles facilitate easy separation and reusability of the adsorbent. Characterization techniques such as X-ray diffraction (XRD) and Raman spectroscopy were employed to confirm the composite's structural integrity and the presence of rGO, highlighting its functional properties. The study's focus lay on investigating mercury removal efficiency across varying pH levels (1–6), temperatures (25 °C), mercury concentrations (10 g/L), adsorbent amounts (0.01–0.05 g/L), and contact times (120–360 s). The findings indicated that optimal mercury adsorption occurred at pH 6, with a 100 s contact time, 25 °C, and 0.05 g of adsorbent. The maximum mercury removal achieved was quantified at 9.15 µg/L, demonstrating the potential of iron nanoparticle-magnetized nano graphene oxide as an efficient and sustainable solution for heavy metal remediation in wastewater treatment applications. The results obtained showed that graphene oxide magnetized with iron nanoparticles can be effectively used to remove mercury from water and wastewater samples.Overall, this research highlights a promising pathway towards addressing the pressing challenge of water pollution with heavy metals.

T. Colborn, C. Kwiatkowski, Kim Schultz et al.

C. Lohri, S. Diener, Imanol Zabaleta et al.

Treatment of biowaste, the predominant waste fraction in low- and middle-income settings, offers public health, environmental and economic benefits by converting waste into a hygienic product, diverting it from disposal sites, and providing a source of income. This article presents a comprehensive overview of 13 biowaste treatment technologies, grouped into four categories: (1) direct use (direct land application, direct animal feed, direct combustion), (2) biological treatment (composting, vermicomposting, black soldier fly treatment, anaerobic digestion, fermentation), (3) physico-chemical treatment (transesterification, densification), and (4) thermo-chemical treatment (pyrolysis, liquefaction, gasification). Based on a literature review and expert consultation, the main feedstock requirements, process conditions and treatment products are summarized, and the challenges and trends, particularly regarding the applicability of each technology in the urban low- and middle-income context, are critically discussed. An analysis of the scientific articles published from 2005 to 2015 reveals substantial differences in the amount and type of research published for each technology, a fact that can partly be explained with the development stage of the technologies. Overall, publications from case studies and field research seem disproportionately underrepresented for all technologies. One may argue that this reflects the main task of researchers—to conduct fundamental research for enhanced process understanding—but it may also be a result of the traditional embedding of the waste sector in the discipline of engineering science, where socio-economic and management aspects are seldom object of the research. More unbiased, well-structured and reproducible evidence from case studies at scale could foster the knowledge transfer to practitioners and enhance the exchange between academia, policy and practice.

Xiaoyan LIU, Yuehua YE, Weidong BAI et al.

The effects of glutamine transaminase (TGase), hydroxypropyl distarch phosphate (HDP), gellan gum and their complex (THG) on the water distribution and protein conformation of low-salt tilapia surimi gel prepared with microwave and ultrasound were analyzed. In addition, the effects of different exogenous substances on the characteristics of low-salt tilapia fish cake were explored through in vitro digestion experiment. The results showed that compared with the control group, THG increased the bound water and immovable water of surimi to 98.71% and 14.75%, respectively, and significantly decreased the free water content (P<0.05). Moreover, THG promoted the transformation of α-helix to β-folding, β-turning and random curling structures. TGase and THG (0.4%) played important roles on gastric emptying rate, protein digestibility and protein hydrolysis degree of low-salt tilapia cake. THG significantly promoted protein decomposition into aggregates with smaller particle size (P<0.05). After the digestion of stomach and duodenum, color of the THG group products was more transparent and clear. And it could be observed by the laser confocal microscope that the red fluorescence highlights of the THG group were significantly reduced, indicating that proteins had been fully digested. Hence, compared with a single exogenous substance, THG not only promoted the binding of water molecules and proteins and induced the change of protein conformation, but also facilitated the exposure of hydrophobic protein groups and the interaction between proteins, and promoted the digestion and absorption of surimi products in the stomach and duodenum. This project provided a theoretical reference for the research on the gel properties of tilapia surimi and the development and application of tilapia fish cake.

Ying Dou, Junling Guo, Junke Shao et al.

Abstract Over the past decade, the most fundamental challenges faced by the development of lithium–sulfur batteries (LSBs) and their effective solutions have been extensively studied. To further transfer LSBs from the research phase into the industrial phase, strategies to improve the performance of LSBs under practical conditions are comprehensively investigated. These strategies can simultaneously optimize the sulfur cathode and Li‐metal anode to account for their interactions under practical conditions, without involving complex preparation or costly processes. Therefore, “two‐in‐one” strategies, which meet the above requirements because they can simultaneously improve the performance of both electrodes, are widely investigated. However, their development faces several challenges, such as confused design ideas for bi‐functional sites and simplex evaluation methods (i. e. evaluating strategies based on their bi‐functionality only). To date, as few reviews have focused on these challenges, the modification direction of these strategies is indistinct, hindering further developments in the field. In this review, the advances achieved in “two‐in‐one” strategies and categorizing them based on their design ideas are summarized. These strategies are then comprehensively evaluated in terms of bi‐functionality, large‐scale preparation, impact on energy density, and economy. Finally, the challenges still faced by these strategies and some research prospects are discussed.

Shaoqi Shi, Xiaoxia Li, Feng Zhang et al.

Oxidative stress is closely linked to aging. Probiotics, whether viable or heat-inactivated, have shown antioxidant properties; however, their effect and mechanism of action in reducing oxidative stress during aging remains underexplored. This study examined the effects of viable and heat-inactivated <i>Lactiplantibacillus plantarum</i> TY-Y10 (<i>L. plantarum</i> TY-Y10) on D-galactose (D-gal)-induced aging in mice, aiming to uncover potential anti-aging mechanisms. Mice were induced to age with D-gal injections, then treated with sodium ascorbate (positive control) or varying doses of <i>L. plantarum</i> TY-Y10 for eight weeks. After treatment, oxidative stress markers, gut microbiota, and liver health were analyzed. Results showed that <i>L. plantarum</i> TY-Y10 decreased malondialdehyde (MDA) and inflammatory markers while increasing antioxidant levels (glutathione, superoxide dismutase, catalase and glutathione peroxidase). Liver damage was reduced, and expression of Nrf2 and related antioxidant enzymes improved. Additionally, <i>L. plantarum</i> TY-Y10 enhanced the abundance of short-chain fatty acid-producing bacteria, boosting fecal short-chain fatty acid levels. In short, both viable and heat-inactivated <i>L. plantarum</i> TY-Y10 mitigated oxidative stress in aging mice by modulating gut microbiota and activating liver antioxidant pathways through the gut-liver axis.

Rui Zhang, Ranran Zhou, Zuting Zhong et al.

Binarized convolutional neural networks (bCNNs) are favored for the design of low-storage, low-power cardiac arrhythmia classifiers owing to their high weight compression rate. However, multi-class classification of ECG signals based on bCNNs is challenging due to the accuracy loss introduced by the binarization operation. In this paper, an effective multi-classifier system is proposed for electrocardiogram (ECG) signals using a binarized depthwise separable convolutional neural network (bDSCNN) with the merged convolution–pooling (MCP) method. The binarized depthwise separable convolution layer is adopted to reduce the increased number of parameters in multi-classification systems. Instead of operating convolution and pooling sequentially as in a traditional convolutional neural network (CNN), the MCP method merges pooling together with convolution layers to reduce the number of computations. To further reduce hardware resources, this work employs blockwise incremental calculation to eliminate redundant storage with computations. In addition, the R peak interval data are integrated with P-QRS-T features to improve the classification accuracy. The proposed bDSCNN model is evaluated on an Intel DE1-SoC field-programmable gate array (FPGA), and the experimental results demonstrate that the proposed system achieves a five-class classification accuracy of 96.61% and a macro-F1 score of 89.08%, along with a dynamic power dissipation of 20 μW for five-category ECG signal classification. The hardware resource usage of BRAM and LUTs plus REGs is reduced by at least 2.94 and 1.74 times, respectively, compared with existing ECG classifiers using bCNN methods.

Noureddine Melouki, Fahad Ahmed, Peyman PourMohammadi et al.

In this paper, a 3D conformal meta-lens designed for manipulating electromagnetic beams via height-to-phase control is proposed. The structure consists of a 40 × 20 array of tunable unit cells fabricated using 3D printing, enabling full 360° phase compensation. A novel automatic synthesizing method (ASM) with an integrated optimization process based on genetic algorithm (GA) is adopted here to create the meta-lens. Simulation using CST Microwave Studio and MATLAB reveals the antenna’s beam deflection capability by adjusting phase compensations for each unit cell. Various beam scanning techniques are demonstrated, including single-beam, dual-beam generation, and orbital angular momentum (OAM) beam deflection at different angles of 0°, 10°, 15°, 25°, 30°, and 45°. A 3D-printed prototype of the dual-beam feature has been fabricated and measured for validation purposes, with good agreement between both simulation and measurement results, with small discrepancies due to 3D printing’s low resolution and fabrication errors. This meta-lens shows promise for low-cost, high-gain beam deflection in mm-wave wireless communication systems, especially for sensing applications, with potential for wider 2D beam scanning and independent beam deflection enhancements.