JOURNAL OF FOOD PROCESSING AND PRESERVATION
·
2020
·Vol. 44
·期 11
·e14896
·
IF 1.405
Yuanhui Li,Na Wan,Zhenfeng Wu,Xuecheng Wang,Ming Yang
In this study, a three-stage microwave-vacuum, pulsed-vacuum, and vacuum drying method (MVD-PVD-VD) was proposed to reduce the quality loss of dried lotus seeds. The effects of MVD-PVD-VD, double combination of microwave vacuum drying, and pulsed vacuum drying (MVD-PVD), PVD, MVD, VD, and hot air drying (HAD) on the quality of lotus seeds were comparatively investigated. Results showed that MVD-PVD-VD took some advantages over the other four drying methods as it allowed the lowest shrinkage, and the highest porosity, rehydration capacity, total phenolic content, and nine phenolics contents. It was shown that with the decreasing moisture content of conversion point for the changing of MVD into PVD and PVD into VD during MVD-PVD-VD, the required drying time and shrinkage ratio decreased, and porosity and rehydration capacity increased. This study demonstrated that MVD-PVD-VD is an effective alternative method for the drying of lotus seeds. Practical applications Lotus seeds, the mature fruit from the Nelumbo nucifer , are important commercial crops and widely consumed as dietary staple or dietary supplement in many countries. Because of its perishable characteristic, fresh lotus seeds must be dehydrated to extend its shelf-life for off-season use. Drying is one of the most important and worldwide spread methods for food preservation. However, conventional drying methods are time-consuming and may cause significant loss in the quality of the product. To this end, a three-stage microwave-vacuum, pulsed-vacuum, and vacuum drying method are proposed in this paper to dehydrate lotus seeds. Results showed that this method is an effective alternative method for the drying of lotus seeds.
研究领域:
食品科学
·
农业工程
✓ 已验证
DOI
高影响因子
Processes
·
2022
·Vol. 10
·期 6
·1183
·
IF 3.352
Haibing Jiang,Jiufen Liu,Huaifa Wang,Runquan Yang,Wenzhi Zhao,Duo Yang,Song Yin,Liang Shen
Foam is essential in the flotation process. However, the gas–liquid–solid three-phase froth produced in the flotation process has very strong stability and is difficult to burst spontaneously. The existence of these froths will reduce the transport capacity of the pulp and affect the working efficiency of subsequent processes, such as filtration of the flotation concentrate. In this study, a new defoaming device is designed by combining mechanical impact with depressurized defoaming and its defoaming mechanism is analyzed theoretically. In addition, the liquid level height and pulp overflow method are applied to characterize the defoaming efficiency of the new defoaming device. The effects of impeller structure, pressure drop, impeller rotation frequency, and aeration rate on defoaming efficiency were studied. The results show that when increasing the pressure drop, the defoaming increases, but it will also enhance the generation of bubbles. The efficiency of combined mechanical–vacuum defoaming technology is superior under low-pressure drop using an SC impeller. Under −1 kpa vacuum condition, it only takes 168 s to eliminate 20 cm flotation froth height with combined mechanical impact, while it takes 453 s under ambient pressure, indicating that under vacuum conditions, the mechanical-defoaming method can significantly improve the defoaming efficiency, and the two have a certain synergistic effect.Keywords:coal;flotation froth;defoaming;vacuum
研究领域:
矿业工程
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
WASTE MANAGEMENT
·
2025
·
IF 7.1
Tong Li,Jiapeng Zhang,Lingxin Kong,Baoqiang Xu,Bin Yang
With the continuous expansion of lithium-ion battery market, the demand for LiCoO 2 remains high and continues to increase annually. However, improper disposal of waste LiCoO 2 batteries causes significant pollution to the environment and waste of resources. This study proposes a novel vacuum carbothermal reduction–vacuum distillation (VCR-VD) method to recover cobalt and lithium oxide from the mixed electrode material of waste batteries. The effects of holding time on the weight loss rate of the raw material, and the effects of holding temperature and carbon content on the purity and direct yield of Co, were investigated to determine the optimal process and parameters. Under the conditions of a reduction temperature of 1500 K, holding time of 3 h, and carbon content of 26.89 wt.% in the raw material, Co with a purity of 95.55 wt.% and a direct yield of 92.4 % was obtained. Simultaneously, Li 2 O with a purity of 98.94 wt.% and a direct yield of 95 % was recovered. This chemical reagent-free process achieves full recovery of waste LiCoO 2 batteries within a short processing time. The experimental results provide a new idea and theoretical support for the industrial-scale recovery of waste lithium-ion batteries.
研究领域:
环境科学
·
冶金工程
·
材料回收
·
清洁能源技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
LWT-FOOD SCIENCE AND TECHNOLOGY
·
2025
·
IF 6.6
Jiawei Cheng,Pengfei Han,Jingyi Wang,Wangting Zhou,Zhenzhou Zhu,Jingren He,Muci Wu,Rui Zhang
Drying is essential for preserving Cardamine violifolia , a selenium-rich Brassicaceae vegetable, and for producing powders for functional foods. However, the effects of different drying methods on its aroma and flavor precursors remain unclear. This study compared the volatile and glucosinolate profiles of C. violifolia subjected to freeze-vacuum drying (FVD), microwave-vacuum drying (MVD), hot-air drying (HAD), and sun drying (SD). HS-SPME-GC–O–MS identified 58 volatile compounds, including 22 aroma-active compounds. Eleven of these were confirmed as key aroma compounds based on odor activity values and aroma recombination/omission experiments. Benzyl isothiocyanate contributed predominantly to the characteristic pungency. Other key odorants included trans-2-hexenal, benzaldehyde, benzeneacetaldehyde, nonanal, β-cyclocitral, 1-octen-3-ol, ketoisophorone, and β-ionone, which contributed to green, sweet, and mushroom-like notes. FVD best preserved the pungent–green flavor of fresh samples, owing to low-temperature dehydration retaining the highest levels of benzyl isothiocyanate and aldehydes. MVD partially retained pungency and generated 3-ethyl-2,5-dimethylpyrazine, which is responsible for roasted nuances. HAD and SD substantially reduced the pungent aromas and enhanced sweet and musty notes. This shift is likely due to extended heat exposure and oxidation, which produced higher concentrations of nonanal, β-cyclocitral, 1-octen-3-ol, 3,5-octadien-2-one, ketoisophorone, β-ionone, and dihydroactinidiolide. Glucosinolate analysis revealed glucotropaeolin (benzyl glucosinolate) as the predominant component, consistent with its major degradation products (benzyl isothiocyanate and benzyl nitrile) in headspace. HAD retained the highest total glucosinolate content due to rapid moisture removal and the stability of glucosinolates at the applied drying temperature. These findings provide useful references for the flavor quality of Brassicaceae vegetables after drying.
✓ 已验证
DOI
高影响因子
Materials
·
2023
·Vol. 16
·期 9
·3395
·
IF 3.4
Mingheng Mao,Shaoqiu Ke,Dingguo Tang,Xiahan Sang,Danqi He
Co magnetic films are widely used in high-frequency magnetic recording and vertical magnetic recording due to their high saturation magnetization and magnetocrystalline anisotropy. In this work, ferromagnetic Co magnetic films were prepared on copper substrate by vacuum evaporation combined with heat treatment (H2atmosphere), to investigate the impact of film thickness and annealing temperature on microstructure and magnetic properties. The results show that with the increase in annealing temperature, the Co thin film physical phase does not change significantly, the crystallinity increases, and the grain size increases, which is consistent with the results obtained from the SEM morphology map of the sample surface, leading to an increase in coercivity. By annealing experiments (atmospheric atmosphere) on Co magnetic films with and without an Al protective layer, as shown by scanning electron microscopy microscopic characterization results, it was verified that the Al layer can protect the inner Co layer from oxidation. As the film thickness increases from 10 to 300 nm, the magnetic properties of Co films change significantly. The saturation magnetization gradually increases from 0.89 to 5.21 emu/g, and the coercivity increases from 124.3 to 363.8 Oe. The remanence ratio of the 10 nm magnetic film is 0.82, which is much higher than the film remanence ratio of 0.46 at 50 nm. This is because when the thickness of the film is between 10 and 50 nm, the magnetic moments partially deviate from the in-plane direction, and the out-of-plane component reduces the film remanence ratio. This study shows that optimizing annealing temperature and film thickness can effectively control the structure and magnetic properties of Co magnetic films, which is of great significance for the development of the magnetic recording field.Keywords:magnetic films;annealing;vacuum evaporation coating;remanence ratio
研究领域:
材料科学
·
物理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Sugar Tech
·
2020
·Vol. 22
·期 5
·830-841
·
IF 1.198
Chen Shuai,Zheng Wenjing,Liu Weixi,Liu Lei,Sun Weidong
Levulinic acid (LA) is an important biomass-based chemical. The preparation of LA from bagasse is of great practical significance for the comprehensive and efficient utilization of biomass. Biomass bagasse is mainly composed of cellulose, hemicellulose, and lignin. The cellulose is mainly degraded to glucose, and hemicellulose is mainly degraded to xylose, with dilute acid treatment at high temperature. In this research, we produced the LA from bagasse with dilute acid treatment at high temperature. The influences of residence time (10–60 min), reaction temperature (170–240 °C), liquid-to-solid ratio (5:1–25:1 mL/g), and acid concentration (1–5%) on the synthesis of LA were investigated by statistical methods, achieving a maximum LA yield of 16.25%. Additionally, LA was isolated and extracted from bagasses hydrolysate by ion exchange and vacuum distillation. The adsorption capacity of different resins was determined and compared. The optimal resin to acquire better adsorption capacity was determined. The better adsorption capacity was obtained when the D301 resin was selected as the filter for ion exchange. The height-to-diameter rate, eluent flow rate, elution volume of ion exchange column were 10, 0.84 BV/h, 56.4 mL, respectively. The eluent was then distilled under vacuum, collecting the components at 130–140 °C. The total yield and purity of LA were 67.1% and 78%, respectively.
研究领域:
生物化学
·
可再生资源工程
✓ 已验证
DOI
高影响因子
MOLECULES
·
2022
·Vol. 27
·期 3
·1057
·
IF 4.927
Kaiyun Fu,Yunzhao Guo,Wenbo Qi,Xianfu Chen,Minghui Qiu,Yiqun Fan
Ceramic membranes have the advantages of high mechanical strength and thermal stability and are promising candidates for membrane distillation. Ceramic membranes are generally designed to have a multilayer structure with different pore sizes to create a high liquid entry pressure and obtain a high permeability. However, these structural characteristics pose significant difficulties in predicting permeate flux in a ceramic membrane contactor for vacuum membrane distillation (VMD). Here, a modeling approach was developed to simulate the VMD process and verified by comparing the simulated results with the experimental data. Furthermore, correlations are proposed to simplify the calculations of permeate flux for VMD using asymmetric ceramic membranes by assuming those multilayers to be an effectively quasi-symmetric layer and by introducing a correction factor. The simulation results indicated that this simplified correlation was effective and enabled a quick estimation of the effect of membrane parameters on permeate flux.Keywords:ceramic membrane;vacuum membrane distillation;permeate flux;modeling
研究领域:
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MOLECULES
·
2024
·Vol. 29
·期 9
·2011
·
IF 4.2
Shengkun Yan,Rong Dong,Jiapeng Yang,Guoqiang Wang
Vacuum saccharification significantly affected the flavor and color of preserved French plums. However, the correlation between color, flavor, and metabolites remains unclear. Metabolites contribute significantly to enhancing the taste and overall quality of preserved French plums. This study aimed to investigate the distinctive metabolites in samples from various stages of the processing of preserved French plums. The PCF4 exhibited the highest appearance, overall taste, and chroma. Furthermore, utilizing UPLC and ESI-Q TRAP-MS/MS, a comprehensive examination of the metabolome in the processing of preserved French plums was conducted. A total of 1776 metabolites were analyzed. Using WGCNA, we explored metabolites associated with sensory features through 10 modules. Based on this, building the correlation of modules and objective quantification metrics yielded three key modules. After screening for 151 differentiated metabolites, amino acids, and their derivatives, phenolic acids, flavonoids, organic acids, and other groups were identified as key differentiators. The response of differential metabolites to stress influenced the taste and color properties of preserved prunes. Based on these analyses, six important metabolic pathways were identified. This study identified changes in the sensory properties of sugar-stained preserved prunes and their association with metabolite composition, providing a scientific basis for future work to improve the quality of prune processing.
研究领域:
食品科学
·
代谢组学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2024
·
IF 8.4
Jingtong Yu,De Sun,Dongmin Yue,Bingbing Li,Tie Zhu,Peixiang Liu
One of the most promising desalination techniques is photothermal membrane distillation (PhMD). The research focus of PhMD technology is material renewal and structural design. Herein, the CuMOF-PVDF photothermal membranes were designed for PhMD. Firstly, a combination of chemical plating and oxidation was used to generate Cu(OH) 2 nanowires (NWs) onto the PVDF membrane. Then, the ligands were chemically bonded with Cu(OH) 2 NWs to grow the photothermal layer formed by the CuMOF hierarchical structure (CMHS). Under sunlight irradiation, the light was trapped in the CMHS, amplifying absorption and conversion of light. The CuMOF-PVDF membrane with the match-like CMHS absorbed 88.6 % of the light, resulting in a surface temperature of 74.3 °C after 600s. Moreover, by reducing the evaporation enthalpy of water, the performance of the CuMOF photothermal layer was comprehensively improved, realizing a water evaporation rate of 1.55 kg‧m −2 ‧h −1 and a high photothermal conversion rate of 71.4 %. During the PVMD process, the feed solution in the CuMOF photothermal layer was fully heated and supplied to the vaporization area, weakening the temperature polarization. Consequently, the flux of the CuMOF-PVDF membrane was 3.07 kg‧m −2 ‧h −1 and a 99.9 % rejection rate, corresponding to an energy efficiency of 85.2 %. The CuMOF-PVDF membrane is an efficient tool for PhMD, helping to advance desalination technologies.
研究领域:
材料科学
·
环境工程
·
能源技术
✓ 已验证
产品关联
DOI
高影响因子
VACUUM
·
2024
·
IF 3.8
Yonghui Yang,Hengwei Yan,Zhanwei Liu,Shenghui Guo,Jin Zhang,Rui Xia
The potential for the preparation of titanium metal through molten salt electrolysis is significant. However, the conventional process of molten salt electrolysis uses chloride molten salt as the electrolyte, which has low solubility for titanium dioxide (TiO 2 ). This paper introduces an innovative approach using a NaF-K 2 TiF 6 system as the molten salt electrolyte, which offered high solubility for TiO 2 . The solubility and dissolution behavior of TiO 2 in NaF-K 2 TiF 6 were analyzed carbon, oxygen and nitrogen analysis (LECO), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and high-temperature Fourier transform infrared spectroscopy (FT-IR). By optimizing the electrolysis temperature, cathode current density, and electrolysis time, titanium metal was successfully prepared, and impurities were removed through water washing and salt washing to obtain pure sponge-like titanium powder. Focused ion beam-scanning electron microscopy (FIB-SEM) analysis revealed that the titanium purity and oxygen content were consistent across both the surface and interior of the powder, thereby indicating effective prevention of oxidation in a vacuum argon (Ar) environment. This method offers the possibility of continuous production of titanium metal through molten salt electrolysis.
研究领域:
材料科学
·
冶金工程
✓ 已验证
DOI
高影响因子
Catalysts
·
2019
·Vol. 9
·期 11
·906
·
IF 3.444
Jieyang Yang,Zequan Zeng,Zhanggen Huang,Yan Cui
In this work, the activation effect of vacuum thermal treatment on MIL-101(Fe) (MIL: Materials of Institute Lavoisier) was investigated for the first time. It demonstrated that vacuum thermal activation could accelerate the activation of persulfate (PS) by MIL-101(Fe), and the enhancement of the catalytic capacity of MIL-101(Fe) was mainly attributed to the change in the FeII/FeIII mixed-valence center. The results of the SEM and XRD showed that vacuum thermal activation had a negligible effect on the crystal structure and particle morphology of MIL-101(Fe). Meanwhile, the higher temperature of vacuum thermal activation caused a higher relative content ratio of FeII/FeIII. A widely used azo dye, X-3B, was chosen as the probe molecule to investigate the catalytic performance of all samples. The results showed that the activated samples could remove X-3B more effectively, and the sample activated at 150 °C without regeneration could effectively activate PS to remove X-3B for at least 5 runs and approximately 900 min. This work highlights the often-overlooked activation effect of vacuum thermal treatment and provides a simple way to improve the catalytic capacity and reusability of MIL-101(Fe) which is beneficial for the application of MIL-101(Fe)/PS systems in azo dye wastewater treatment.Keywords:vacuum thermal activation;MIL-101(Fe);persulfate;azo dye
研究领域:
环境科学
·
催化
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Nanomaterials
·
2022
·Vol. 12
·期 4
·624
·
IF 5.719
Yanjun Zhang,Yaxin Zhao,Rui Guo,Zengxing Zhang,Dan Liu,Chenyang Xue
Currently, there are several thermoelectric materials, such as Ag2Te, Bi2Te3, and Sb2Te3, that have been investigated for thermoelectric applications. However, the toxicity and rarity of most of these materials make them unsuitable for practical applications. In contrast, silver selenide (Ag2Se) is an abundant and environment-friendly thermoelectric material. This study provides a facile synthetic approach for preparing high-performance, low-cost, and flexible Ag2Se thermoelectric films. Ag2Se nanomaterials were prepared based on the chemical template method, and the reaction solution concentration was varied to systematically investigate the effects of reaction solution concentration on the characterization and thermoelectric properties of Ag2Se nanomaterials. For convenience of testing, the flexible Ag2Se films were prepared on porous nylon membranes using vacuum-assisted filtration. The prepared thermoelectric films were tested using an X-ray diffractometer, scanning electron microscope, Seebeck coefficient tester, and Hall tester. The film prepared from the solution with the lowest concentration (18.0 mM) demonstrated the best thermoelectric performance, with a maximum power factor of 382.18 μW∙m−1∙K−2at ~400 K. Additionally, a cold-pressing treatment could effectively enhance the electrical conductivity of the film, without damaging the substrate, as the conductivity of the film remained at 90% of the original value after 1500 bending cycles.Keywords:silver selenide;vacuum-assisted filtration;flexible film;thermoelectric properties
研究领域:
材料科学
·
能源技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）