Hasil untuk "Chemical technology"

Xuezhen Ba, Yu Zhong

Fiscal transfers are a key policy instrument for supporting grain production, and a systematic assessment of their effects offers a critical basis for improving the design of incentive-based grain production policies. Unlike most existing studies, which primarily examine fiscal transfers from the perspective of improving farm households’ welfare and micro-level production decisions, this paper focuses on their impact on the grain production performance of major grain-producing counties, which account for over 80% of China’s grain output. Utilizing panel data from 1319 county-level units in China, this study employs a difference-in-differences (DID) approach to evaluate the impact of the “Reward Policy for Major Grain-Producing Counties (RPMGC)”, a central-to-county fiscal transfer program, on grain production. The empirical results indicate that: First, the reward policy significantly promotes grain production, and this finding remains robust across a series of robustness tests. Second, from a temporal perspective, the policy’s impact follows a trend of initially increasing and then decreasing over time, suggesting that the policy effects lack long-term sustainability. Third, mechanism analysis reveals that the policy enhances grain production by fostering technological advancement, mitigating production risks, and facilitating scaled-up production. Fourth, further analysis indicates that the policy effects are more pronounced in counties located within major grain-producing regions and those experiencing higher fiscal pressure. These findings provide valuable insights for improving the design of intergovernmental grain production incentives, refining grain production incentive mechanisms, and consolidating national food security.

Ligia Soares Lima, Jessyca Sousa de Brito, Marcelo Ribeiro-Alves et al.

Jaboticaba (<i>Plinia cauliflora</i>), a Brazilian native fruit rich in bioactive compounds, exhibits potent anti-inflammatory and antioxidant properties. This pilot study evaluated the effects of jaboticaba peel supplementation on inflammatory and oxidative stress markers and uremic toxins among patients with chronic kidney disease (CKD) undergoing hemodialysis (HD) and explored its molecular effects in LLC-PK1 renal cells. A randomized, controlled clinical trial was conducted with 27 patients (55.0 [19.5] years, BMI 24.3 [3.8] kg/m²) on regular HD. Participants were allocated to receive the jaboticaba peel formulation (3.3 g/day, equivalent to ~667 mg of phenolic compounds) for 3 weeks or to routine treatment (control). Plasma levels of interleukin (IL)-1β and IL-17E (ELISA), lipid peroxidation (TBARS), protein carbonylation, and plasma levels of uremic were analyzed. LLC-PK1 cells were treated with 100 µL of jaboticaba peel formulation at different concentrations, and a panel of inflammatory genes was evaluated. While plasma IL-1β and IL-17E concentrations were increased in the control group, the jaboticaba group exhibited no significant changes, suggesting anti-inflammatory protection. Transcriptomic analysis revealed downregulation of key components of the TLR–MYD88–NF-κB–IL-1 axis after cell treatment. Additionally, cells treated with jaboticaba formulation (1.5%) showed reduced ROS levels, indicating antioxidant capacity. In conclusion, supplementation with jaboticaba peel attenuated the increase in pro-inflammatory markers in HD patients. These results suggest that jaboticaba peel holds promise as an adjuvant nutritional intervention for chronic inflammation in CKD.

Kyung-Jik Lim, Hyun-Jun Kim, Yu-Jin Heo et al.

Polycyclic aromatic hydrocarbons (PAHs) are recognized carcinogens that enter the food chain through pre-existing environmental contamination (air, water, soil), and their formation and accumulation during food preparation and processing involve high temperatures. We established a modified QuEChERS GC-MS method that couples <i>n</i>-hexane-saturated acetonitrile containing 1% toluene with a freeze-out step. Compared to the previously reported ACN QuEChERS protocol, this method enhanced PAH desorption and suppressed lipid interference across four matrices. The method linearity (R² ≥ 0.99), limit of detection (LOD, from 0.03 to 0.20 μg/kg), limit of quantitation (LOQ, from 0.10 to 0.60 μg/kg), and intra-/inter-day precision (≤5.7% RSD) all satisfied AOAC criteria. The modified QuEChERS reduced solvent consumption and shortened preparation time compared to other conventional extraction methods. The developed method was applied to 302 retail food samples, and <i>Kezuribushi</i> was found to have the highest concentration of the 4PAHs, reaching 22.0 µg/kg. Risk assessment based on EFSA’s margin-of-exposure (MOE) approach identified grilled chicken feet (MOE = 7604) as a potential health concern, as this value falls below EFSA’s threshold of 10,000 for potential risk characterization. The validated method enables sensitive and scalable monitoring of PAHs in complex food matrices within the tested matrices and conditions.

Antoine Baron, Corentin Scholaert, David Guérin et al.

Conducting polymer dendrite (CPD) morphogenesis is an electrochemical process that unlocks the potential to implement in materio evolving intelligence in electrical systems: As an electronic device experiences transient voltages in an open-space wet environment, electrically conductive structures physically change over time, programming the filtering properties of an interconnect as a non-linear analog device. Mimicking the self-preservation strategies of some sessile organisms, CPDs adapt their morphology to the environment they grow in. Either studied as an electrochemical experiment or as neuromorphic devices, the dependence of CPDs' electrical properties on the chemical nature of their environment is still unreported, despite the inter-dependence between the electrical properties of the electrogenerated material and the chemical composition of their growth medium. In this study, we report on the existing intrication between the nature and concentration of the electrolytes, electroactive compounds and co-solvents and the electrical and the electrochemical properties of CPDs in water. CPDs exhibit various chemical sensitivities in water: their morphology is highly dependent on the nature of the chemical resources available in their environment. The selection of these resources therefore critically influence morphogenesis. Also, concentrations have different impacts on growth dynamics, conditioning the balance between thermodynamic and kinetic control on polymer electrosynthesis. By correlating the dependencies of these evolving objects with the availability of the chemical resources in an aqueous environment, this study proposes guidelines to tune the degree of evolution of electronic materials in water. Such hardware is envisioned to exploit the chemical complexity of real world environments as part of information processing technologies.

Eugene V. Stepanov, Alexander F. Gutsol

A theoretical approach to describing transport of an entire ensemble of clusters with different sizes as a single species in gas has been developed. The major assumption is an existence of local partial chemical equilibrium between the clusters. It is shown that thermal diffusion emerges in the collective description as a significant factor even if it is negligible when transport of the original molecular species is considered. Analytical expressions for the effective diffusion and thermal diffusion coefficients at temperature, pressure, and chemical composition gradients have been derived. The theory has been applied to a technology of H2S conversion in a centrifugal plasma-chemical reactor and has made it possible to account for sulfur clusters in numerical process modeling.

Xiaohu Sun, Fei Liu, Yu Zhao et al.

The threat power transmission and distribution projects pose to the ecological environment has been widely discussed by researchers. The scarcity of early environmental monitoring and supervision technologies, particularly the lack of effective real-time monitoring mechanisms and feedback systems, has hindered the timely quantitative identification of potential early-stage environmental risks. This study aims to comprehensively review the literature and analyze the research context and shortcomings of the advance warning technologies of power transmission and distribution projects construction period using the integrated space–sky–ground system approach. The key contributions of this research include (1) listing ten environmental risks and categorizing the environmental risks associated with the construction cycle of power transmission and distribution projects; (2) categorizing the monitoring data into one-dimensional, two-dimensional, and three-dimensional frameworks; and (3) constructing the potential environmental risk knowledge system by employing the knowledge graph technology and visualizing it. This review study provides a panoramic view of knowledge in a certain field and reveals the issues that have not been fully explored in the research field of monitoring technologies for potential environmental damage caused by power transmission and transformation projects.

Yan Gao, Lin Zhang, Weiwei Chen et al.

Although great progress has been made in the development of hybrid rice with increased yield, challenges for the improvement of grain quality still remain. In this study, the textural properties of cooked rice and physicochemical characteristics of starch were investigated for 29 new hybrid rice derived from 5 sterile and 11 restorer rice lines. Except for one sterile line Te A (P1) with high apparent amylose content (AAC) (26.9%), all other parents exhibited a low AAC. Gui 263 demonstrated the highest AAC (20.6%) among the restorer lines, so the Te A/Gui 263 hybrid displayed the highest AAC (23.1%) among all the hybrid rice. The mean AAC was similar between sterile, restorer lines and hybrid rice. However, the mean hardness of cooked rice and gels of sterile lines were significantly higher than that of restorer lines and hybrid rice (<i>p</i> < 0.05). Pasting temperature and gelatinization temperatures were significantly higher in the hybrids than in the restorer lines (<i>p</i> < 0.05). Cluster analysis based on the physicochemical properties divided the parents and hybrid rice into two major groups. One group included P1 (Te A), P12 and P14 and three hybrid rice derived from P1, while the other group, including 39 rice varieties, could be further divided into three subgroups. AAC showed significant correlation with many parameters, including peak viscosity, hot peak viscosity, cold peak viscosity, breakdown, setback, onset temperature, peak temperature, conclusion temperature, enthalpy of gelatinization, gel hardness and cooked rice hardness (<i>p</i> < 0.05). Principal component analysis revealed that the first component, comprised of the AAC, peak viscosity, breakdown, setback, onset temperature, peak temperature, conclusion temperature and gel hardness, explained 44.1% of variance, suggesting AAC is the most important factor affecting the grain quality of hybrid rice. Overall, this study enables targeted improvements to key rice grain quality attributes, particularly AAC and textural properties, that will help to develop superior rice varieties.

Freddy Tuxworth, Adnan Aijaz

The global energy landscape is experiencing a significant transformation driven by increased awareness of climate change and rapid technological advancements in renewable energy and electric vehicles (EVs). Packetized energy management (PEM) schemes are gaining attention as a potential solution for power management for effective load control. This study presents the development of a co-simulation platform to investigate integration of vehicle-to-grid (V2G) with packetized energy trading (PET) in microgrid scenarios. The platform facilitates the interaction between EVs and prosumers, with a focus on responsive loads, and solar photovoltaic (PV) as intermittently available resources. Using the developed co-simulation, this study evaluates how V2G-capable EVs can enhance the stability and efficiency of PET-based microgrids. The results demonstrate the capability of V2G EVs to act as an energy reservoir, effectively managing demand-side load, thus mitigating its fluctuation from available supply while maintaining quality-of-service.

Xiangyu Wu, Hailiang Zhang, Yang Yang et al.

In this paper, we present our champion solution to the Global Artificial Intelligence Technology Innovation Competition Track 1: Medical Imaging Diagnosis Report Generation. We select CPT-BASE as our base model for the text generation task. During the pre-training stage, we delete the mask language modeling task of CPT-BASE and instead reconstruct the vocabulary, adopting a span mask strategy and gradually increasing the number of masking ratios to perform the denoising auto-encoder pre-training task. In the fine-tuning stage, we design iterative retrieval augmentation and noise-aware similarity bucket prompt strategies. The retrieval augmentation constructs a mini-knowledge base, enriching the input information of the model, while the similarity bucket further perceives the noise information within the mini-knowledge base, guiding the model to generate higher-quality diagnostic reports based on the similarity prompts. Surprisingly, our single model has achieved a score of 2.321 on leaderboard A, and the multiple model fusion scores are 2.362 and 2.320 on the A and B leaderboards respectively, securing first place in the rankings.

GANG Fa-yuan, SONG Zhi-jun, DING You-qian et al.

Alkali residue was dissolved by the ammonium hydrogen fluoride method, in which the uranium content is determined to be (16.7±0.3)%(n=6) by inductively coupled plasma optical emission spectrometry(ICP-AES). By means of XRD and SEM-EDS, the main uranium occurrence form of alkali residue was determined. It includes UO3, fluoride(CaF2, NaF, MgF2, UF4, etc), SiO2-P2O5-UO3, Cr2O3-Fe2O3 and other solid melts, and the forms of UO3 being wrapped by the above solid melts. Using TBP-HNO3 as complexing agent, the effects of various parameters were investigated on the lab-scale supercritical CO2 fluid extraction facility. The extraction parameters are optimized: the particle size is 0.250-0.420 mm, saturated Al(NO3)3 solution of w=25% alkali residue is used as salting agent, the mole ratio of TBP-HNO3/U is ≥50, the extraction temperature is 50 ℃ and the pressure is 20 MPa. Under these conditions, the extraction rate of uranium in the alkali residue reaches as high as 98.5% within 2 h. This work provides a new method for the recovery of uranium in alkali residue.

Fan Chen, William M. Jacobs

Biomolecules composed of a limited set of chemical building blocks can co-localize into distinct, spatially segregated compartments known as biomolecular condensates. While many condensates are known to form spontaneously via phase separation, it has been unclear how immiscible condensates with precisely controlled molecular compositions assemble from a small number of chemical building blocks. We address this question by establishing a connection between the specificity of biomolecular interactions and the thermodynamic stability of coexisting condensates. By computing the minimum interaction specificity required to assemble condensates with target molecular compositions, we show how to design heteropolymer mixtures that produce compositionally complex condensates using only a small number of monomer types. Our results provide insight into how compositional specificity arises in naturally occurring multicomponent condensates and demonstrate a rational algorithm for engineering complex artificial condensates from simple chemical building blocks.

Matthew S. Robinson, Jochen Küpper

In this perspective, we discuss how one can initiate, image, and disentangle the ultrafast elementary steps of thermal-energy chemical dynamics, building upon advances in technology and scientific insight. We propose that combinations of ultrashort mid-infrared laser pulses, controlled molecular species in the gas phase, and forefront imaging techniques allow to unravel the elementary steps of general-chemistry reaction processes in real time. We detail, for prototypical first reaction systems, experimental methods enabling these investigations, how to sufficiently prepare and promote gas-phase samples to thermal-energy reactive states with contemporary ultrashort mid-infrared laser systems, and how to image the initiated ultrafast chemical dynamics. The results of such experiments will clearly further our understanding of general-chemistry reaction dynamics.

Romuald Gaillard, Alice Marciniak, Guillaume Brisson et al.

Ultra-high pressure homogenization (UHPH) is a promising method for destabilizing and potentially improving the techno-functionality of the egg yolk granule. This study’s objectives were to determine the impact of pressure level (50, 175 and 300 MPa) and number of passes (1 and 4) on the physico-chemical and structural properties of egg yolk granule and its subsequent fractions. UHPH induced restructuration of the granule through the formation of a large protein network, without impacting the proximate composition and protein profile in a single pass of up to 300 MPa. In addition, UHPH reduced the particle size distribution up to 175 MPa, to eventually form larger particles through enhanced protein–protein interactions at 300 MPa. Phosvitin, apovitellenin and apolipoprotein-B were specifically involved in these interactions. Overall, egg yolk granule remains highly stable during UHPH treatment. However, more investigations are needed to characterize the resulting protein network and to evaluate the techno-functional properties of UHPH-treated granule.

Fernande G. Honfo, Mênouwesso H. Hounhouigan, D. Sylvain Dabade et al.

gboma is a leafy vegetable commonly consumed in Benin, which plays an important role in food security. This study assessed the handling and preservation practices as well as quality attributes of gboma along the supply chain in Southern Benin. A survey among 785 people (285 producers, 180 whole salers/retailers, and 326 consumers) living in four Departments of Benin was conducted to evaluate the consumption frequency, the transportation mode, the preservation methods and quality attributes of gboma during purchasing. The survey revealed that, in general, gboma sauce is consumed twice to three times a month in all the departments covered. Different practices, including humidification, were used to preserve the leaves during selling. Traditional baskets or old clothes were used for the transportation and storage of gboma. Important quality attributes mostly used by actors during purchasing were freshness and color followed by physical damage and, to a lesser extent, weight and leaf surface at different degrees. gboma is currently sold in informal markets; however, improving handling and selling practices could preserve the freshness of this leafy vegetable that could then be placed in conventional supermarkets. Thereby, the selling and consequently the production level will increase, with positive impact on the income of producers.

Danny Horta, Ricardo P. Schiavon, J. Ted Mackereth et al.

Galactic haloes in a $Λ$-CDM universe are predicted to host today a swarm of debris resulting from cannibalised dwarf galaxies. The chemo-dynamical information recorded in their stellar populations helps elucidate their nature, constraining the assembly history of the Galaxy. Using data from APOGEE and \textit{Gaia}, we examine the chemical properties of various halo substructures, considering elements that sample various nucleosynthetic pathways. The systems studied are Heracles, \textit{Gaia}-Enceladus/Sausage (GES), the Helmi stream, Sequoia, Thamnos, Aleph, LMS-1, Arjuna, I'itoi, Nyx, Icarus, and Pontus. Abundance patterns of all substructures are cross-compared in a statistically robust fashion. Our main findings include: {\it i)} the chemical properties of most substructures studied match qualitatively those of dwarf Milky Way satellites, such as the Sagittarius dSph. Exceptions are Nyx and Aleph, which are chemically similar to disc stars, implying that these substructures were likely formed \textit{in situ}; {\it ii)} Heracles differs chemically from {\it in situ} populations such as Aurora and its inner halo counterparts in a statistically significant way. The differences suggest that the star formation rate was lower in Heracles than in the early Milky Way; {\it iii)} the chemistry of Arjuna, LMS-1, and I'itoi is indistinguishable from that of GES, suggesting a possible common origin; {\it iv)} all three Sequoia samples studied are qualitatively similar. However, only two of those samples present chemistry that is consistent with GES in a statistically significant fashion; {\it v)} the abundance patterns of the Helmi stream and Thamnos are different from all other halo substructures.

Ronggang Yue, Humei Wang, Ting Jin et al.

Satellites have many high-, medium-, and low-frequency micro vibration sources that lead to the optical axis jitter of the optical load and subsequently degrade the remote sensing image quality. To address this problem, this paper developed an image motion detection and restoration method based on an inertial reference laser, and describe edits principle and key components. To verify the feasibility and performance of this method, this paper also built an image motion measurement and restoration system based on an inertial reference laser, which comprised a camera (including the inertial reference laser unit and a Hartmann wavefront sensor), an integrating sphere, a simulated image target, a parallel light pope, a vibration isolation platform, a vibration generator, and a 6 degrees of freedom platform. The image restoration principle was also described. The background noise in the experiment environment was measured, and an image motion measurement accuracy experiment was performed. Verification experiments of image restoration were also conducted under various working conditions. The experiment results showed that the error of image motion detection based on the inertial reference laser was less than 0.12 pixels (root mean square). By using image motion data to improve image quality, the modulation transfer function (MTF) of the restored image was increased to 1.61–1.88 times that of the original image MTF. The image motion data could be used as feedback to the fast steering mirror to compensate for the satellite jitter in real time and to directly obtain high-quality images.

Naseer T. Alwan, S.E. Shcheklein, Obed M. Ali

Solar water distillation is an effective technology for producing potable water using sustainable energy sources. However, the widespread use of this technology in industrial and domestic applications is hindered by low daily production compared to other methods. In this study, a new modification was introduced by placing a hollow cylinder inside a solar distiller and then integrating the cylindrical solar distiller with a solar heater (modified solar still). An economic analysis and study of the chemical and physical properties of the modified solar still (MSS) were carried out. The MSS produced a 296–300% increase in distillate water yield compared to a commercial solar still (CSS) on 17 July 2019, and reached 400% in other months depending on weather conditions. The costs of producing a liter of distilled water from the conventional and modified solar stills were 0.0282 and 0.0268 $/lit, respectively. Thus, the proposed solar distiller design is economically feasibile, reducing the cost of production compared to a conventional distiller and previous studies. The distillate water produced by the MSS and CSS has given the best results to all TDS, pH, and electrical conductivity tests according to local and international standards.

Ying Wang, Shuang-Shuang Gong, Yue Liu et al.

Paul Marillonnet, Maryline Laurent, Mikaël Ates

This paper presents a survey of technologies for personal data self-management interfacing with administrative and territorial public service providers. It classifies a selection of scientific technologies into four categories of solutions: Personal Data Store (PDS), Identity Manager (IdM), Anonymous Certificate System and Access Control Delegation Architecture. Each category, along with its technological approach, is analyzed thanks to eighteen identified functional criteria that encompass architectural and communication aspects, as well as user data lifecycle considerations. The originality of the survey is multifold. First, as far as we know, there is no such thorough survey covering such a panel of a dozen of existing solutions. Second, it is the first survey addressing Personally Identifiable Information (PII) management for both administrative and private service providers. Third, this paper achieves a functional comparison of solutions of very different technical natures. The outcome of this paper is the clear identification of functional gaps of each solution. As a result, this paper establishes the research directions to follow in order to fill these functional gaps.

Junwei Zang, Vahid Towhidlou, Mohammad Shikh-Bahaei

Among all requirements for vehicle-to-everything (V2X) communications, successful delivery of packets with small delay is of the highest significance. Especially, the delivery of a message before a potential accident (i.e. emergency message) should be guaranteed. In this work, we propose a novel cross-layer design to enhance the delivery of emergency messages so that accidents can be further avoided. Particularly, in the PHY layer, imperfect full-duplex (FD) simultaneous transmitting and sensing is analysed and dynamic thresholds for determining the channel status before and during transmissions are mathematically formulated. Then a novel FD MAC protocol, named priority-based multiple access (PBMA), based on prioritised messaging between different vehicles is proposed. Average collision probability, collision duration, waiting time as well as successful delivery rate of the system are formulated too. The delivery performance of emergency messages is also mathematically derived. In addition, comparisons have been made among three different mechanisms. Benchmark is the DSRC standard which uses half-duplex (HD) technology with enhanced distributed channel access (EDCA) protocol. We also compare our proposed protocol with FD EDCA. Simulations have verified the accuracy of our analysis. They have also illustrated the delivery of emergency messages has been enhanced by deploying our proposed design.