FOOD CHEMISTRY
·
2015
·
IF 3.391
Wenjun Wang,Xiaobin Ma,Yuting Xu,Yongqiang Cao,Zhumao Jiang,Tian Ding,Xingqian Ye,Donghong Liu
The extraction of pectin from grapefruit peel by ultrasound-assisted heating extraction (UAHE) was investigated using response surface methodology and compared with the conventional heating extraction (CHE). The optimized conditions were power intensity of 12.56 W/cm 2 , extraction temperature of 66.71 °C, and sonication time of 27.95 min. The experimental optimized yield was 27.34%, which was well matched with the predicted value (27.46%). Compared with CHE, UAHE provided higher yield increased by 16.34% at the temperature lowered by 13.3 °C and the time shortened by 37.78%. Image studies showed that pectin extracted by UAHE showed better color and more loosen microstructure compared to that extracted by CHE, although Fourier Transform Infrared Analysis indicated insignificant difference in their chemical structures. Furthermore, UAHE pectin possessed lower viscosity, molecular weight and degree of esterification, but higher degree of branching and purity than CHE pectin, indicating that the former was preliminarily modified during the extraction process.
研究领域:
食品科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
GEOTHERMICS
·
2019
·
IF 3.47
Xianzhi Song,Rui Zheng,Ruixia Li,Gensheng Li,Baojiang Sun,Yu Shi,Gaosheng Wang,Shijie Zhou
In the exploitation of geothermal resources, geothermal single-well heat extraction technology can realize geothermal development without extracting water, which has a wide application prospect. The single-well heat extraction relies on heat conduction between wellbore and reservoir, and heat convection between wellbore and reservoir water. Therefore, the thermal resistance between wellbore and reservoir is an important factor affecting performance of heat extraction. Employing cement with thermal conductive materials in the thermal recovery section of geothermal reservoir is an effective method to enhance heat extraction performance. The study presents a method of producing thermal conductive cement by mixing oil well cement with thermal conductive materials, including graphite, ferrum and copper. Then thermal conductivity and compressive strength tests are carried out, and the influence of thermal conductive material exerted on the thermal conductivity of cement paste is studied. Moreover, relations between porosity and thermal conductivity of cement paste, and relations between particle continuity and thermal conductivity of cement paste are studied by porosity test and SEM scanning. The study demonstrates that with graphite increases, the porosity of cement paste decreases firstly and then increases, and the thermal conductivity of cement paste increases firstly and then decreases; With ferrum increases, the porosity of cement paste decreases, and the thermal conductivity of cement paste increases; With copper increases, the porosity of cement paste decreases, and the thermal conductivity of cement paste increases; As the temperature rises, the thermal conductivity of cement paste decreases gradually; Thermal conductive materials can enhance thermal conduction in cement, and pore would provide thermal insulation; On the condition of improve thermal conductivity, cement with 0.05-0.15 graphite, cement with 0.05-0.20 ferrum and cement with 0.05-0.20 copper can meet requirements. The results of this study provide theoretical guidance for improving the thermal conductivity of cement in geothermal well.
研究领域:
土木工程
·
能源科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ENVIRONMENTAL MANAGEMENT
·
2025
·
IF 8.4
Lang Xing,Guanghui Li,Jun Luo,Hao Jiang
Large-scale comprehensive utilization of coal fly ash (CFA) has become an inevitable issue. In this study, one-step mixed alkali (KOH + CaO) hydrothermal extraction of alumina and synergistic preparation of soil amendment from CFA was developed. The Al 2 O 3 and SiO 2 in CFA were dissolved rapidly under the action of KOH, and the dissolved silicate was transformed into tobermorite under the action of CaO. This approach realized efficient separation of aluminum and silicon with simultaneous regeneration of KOH. The optimum leaching ratio of Al 2 O 3 was 56.44 %, while the leaching ratio of SiO 2 was 3.38 %. The dealuminated CFA (DACFA) was simultaneously transformed into porous aggregates intertwined with tobermorite fibers, which are rich in Si, Ca and K 2 O nutrients due to the excellent cation exchange of tobermorite or formation of tobermorite and leucite minerals. The effective Si, Ca, and K 2 O in F90 were 16.19 %, 20.45 % and 5.31 %, respectively, which met the primary standard of fertilizer. The pot experiment showed that DACFA effectively improved soil quality and immobilized soil heavy metals, thereby accelerating the growth of pakchoi. Through this technology, the high-value transformation from CFA to alumina and soil amendments is expected to facilitate large-scale utilization of CFA and enhance agricultural productivity.
研究领域:
环境科学
·
材料科学
·
农业科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2024
·
IF 7.7
Na Yang,Yamei Jin,Yuyi Zhou,Xiaoqun Zhou
A novel electromagnetic heat extraction method was presented, whereby mandarin peels residue solution was located in a winding coil subjected to an oscillating magnetic field, and the pectin was extracted under appropriate conditions. Numerical relationships between applied magnetic field and induced electric field (IEF) in the extraction process were elaborated. The results showed that the induced current density, IEF and terminal temperature increased with increasing magnetic field. The maximum current density of 0.35 A/cm corresponds to the highest terminal temperature of 84.6 °C and IEF intensity of 26.6 V/cm. When magnetic field intensity was 1.39 T and the extraction time was 15 min, the maximum yield of pectin reached 9.16 %. In addition, all treatments impacted the ash content, protein content, water-holding capacity (WHC), and oil-holding capacity (OHC) of the obtained pectin. The pectin extracted by electromagnetic heat had the lowest DE value of 71.3 % with 126.55 kDa molecular weight, while the GalA content was at the highest level of 76.18 %. After different treatments, the composition of pectin monosaccharides changed, but there were slight differences in the composition of pectin polysaccharides. Moreover, the electromagnetic heat extracted pectin had light color and an obvious surface fragmentation of the peel residue.
研究领域:
食品科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
WASTE MANAGEMENT
·
2023
·
IF 8.1
Man Zhang,Rubo Tian,Siyang Tang,Kejing Wu,Binshen Wang,Yingying Liu,Yingming Zhu,Houfang Lu,Bin Liang
Bamboo pulp and papermaking produce a lot of bamboo powder waste, and its resource utilization is of great significance for biomass refining and environmental protection. Here, we propose an integrated approach involving mechanical activation, hydrothermal extraction, and deep eutectic solvents (DESs) multiple delignification for the efficient separation of bamboo powder. Among seven carboxylic acids based DESs, choline chloride (ChCl)-lactic acid (La) DES (1:1) is the most effective, with over 78.0% lignin removal and 88.9% cellulose retained after mechanical-hydrothermal (180 °C, 5 h)-DES (110 °C, 12 h) treatment. Notably, 84.7% of delignification is achieved after three times of ChCl-La DES treatment at 70, 90, and 110 °C respectively. The delignification rate is negatively correlated with the amount of carboxyl group in the DESs. The lower the p K a value, the higher the delignification rate. Additionally, the selectivity for lignin is improved with decreasing solvent polarity. DES treatment effectively degrades the guaiacyl unit lignin fractions and disrupts several β-aryl-ether bonds (e.g., β-O-4, β-β, and β-5). Furthermore, DESs exhibit good recyclability, with less than 10% reduction in delignification after three cycles. Theory calculations confirm that ChCl-carboxylic acid DESs could compete with lignin to break hydrogen bonds in lignocellulosic biomass by providing their chloride, hydroxyl, and carboxyl groups. Overall, this study demonstrates the practical significance of multistage treatment for the effective fractionation of biomass into its three components.
研究领域:
生物质精炼
·
环境科学
·
林业工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Biomass Conversion and Biorefinery
·
2022
·
IF 4.05
Lin Yingnan,Wang Chan,Yu Guofeng,Wang Haoya,Liang Rongning,Kong Fanyu,Song Dean
Utilizing renewable and green biomass to supply energy and chemicals has emerged as a fascinating research field due to its great potential to solve the problems of fossil resource shortage and ecological deterioration throughout the world. However, to date it has been an open challenge to achieve efficient biomass utilization for ultimately replacing the petrochemical industry. We report here a general and efficient strategy for complete utilization of biomass. Such strategy is accomplished by combination of hydrothermal extraction based on microwave heating and natural seawater extraction and further pyrolysis of residual solid. Bifunctional natural seawater not only functions as a solvent for carbohydrate conversion but also provides chloride element for promotion of pyrolysis of lignin in residual solid into high-value-added petrochemicals. Such strategy can achieve full biomass utilization with extremely high carbohydrate conversion efficiency of 91.5% and preferred production of aromatics such as 37.5% benzenes and 36.4% phenols in all identified pyrolytic compounds. This may pay the way for replacing fossil resources with biomass.
研究领域:
能源与环境科学
·
化学工程
·
生物质转化
✓ 已验证
产品关联
DOI
高影响因子
FOOD HYDROCOLLOIDS
·
2016
·
IF 3.858
Wenjun Wang,Xiaobin Ma,Peng Jiang,Lyulin Hu,Zijian Zhi,Jianle Chen,Tian Ding,Xingqian Ye,Donghong Liu
In the present study, properties of pectin from grapefruit ( Citrus paradisi Macf. cv. Changshanhuyou) peel extracted by ultrasound-assisted extraction (UP), were compared with those of pectin extracted by conventional heating extraction (CP). UP exhibited a lower molecular weight ( M w ) but more concentrated M w distribution than CP. Although both UP and CP were high-methoxyl pectin, UP showed significantly lower degree of methoxylation but higher degree of acetylation. Monosaccharide composition analysis showed that the molecular structure of UP possessed more branch chains than CP, but little difference was observed in the chemical structures between UP and CP from FT-IR and NMR spectra analysis. X-ray diffraction (XRD) analysis further confirmed that UP had decreased level of crystallinity than CP. Moreover, thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) indicated UP had higher thermal stability. UP exhibited lower apparent viscosity and elasticity than CP, showing that ultrasound affected the rheological properties of pectin. Besides, antioxidant activity and lipase inhibitory capacity of UP significantly enhanced compared with CP.
研究领域:
食品科学
·
生物化学
✓ 已验证
产品关联
DOI
高影响因子
ACS ES&T Water
·
2023
·
IF 5.3
Xiaocai Cui,Tian Ren,Qingqing Ren,Beibei Wu,Yun Zhou,Siqing Xia,Bruce E. Rittmann
Extracellular polymeric substances (EPS) affect the formation, properties, and function of biofilms. Understanding the roles of EPS in biofilm-related processes depends on reliable extraction and evaluation methods. However, differentiating true EPS from intracellular organic polymers released by cell lysis has proven to be difficult during EPS extraction. In this study, thermal and cation exchange resin (CER) treatments were used to extract biofilm EPS. SYTOX Green (SG) dye was used to stain nucleic acid (NA), and the enhanced fluorescence signal (FS) from the NA-SG complex was sensitively recorded by flow cytometry (FC). Results showed that thermal extraction could achieve effective EPS release, but a higher temperature and longer time caused a significant cell activity decline, protein denaturation, and cell lysis. In contrast, CER extraction had no effects on cell activity and organics denaturation, and it only caused minor cell lysis at a high CER dose. Combining all the results indicates that CER extraction using 70 g-CER/g-VSS for 2 h provided reliable and efficient extraction of biofilm EPS: high EPS extraction efficiency with minimal EPS denaturation, cell lysis, and loss of cell activity. FC combined with SG staining should be applicable for evaluating the effectiveness of EPS extraction from any microbial aggregates.
研究领域:
微生物学
·
环境工程
·
分析化学
✓ 已验证
产品关联
DOI
高影响因子
ENERGY CONVERSION AND MANAGEMENT
·
2020
·
IF 8.208
Xiaoxiang Li,Jingyi Zhang,Benwei Fu,Chengyi Song,Wen Shang,Peng Tao,Tao Deng
Erythritol (ET) has received increasing research attention for medium-temperature phase change solar-thermal energy storage. However, ET suffers from serious supercooling, low thermal conductivity, poor solar absorption and leakage after melting, which lead to low solar-thermal energy harvesting and releasing efficiency. Herein, we simultaneously overcome these inherent shortcomings by impregnating ET within surface-roughened hydrophilic copper foam, which is prepared by subsequent oxidization of commercial copper foam and thermal reduction under hydrogen, and using stably dispersed crumpled graphene particles as the solar-thermal converter. Such oxidization-reduction-treated copper foam not only provides numerous heterogeneous nucleation sites and lowers the nucleation energy barrier for forming ET crystals during the solidification process, but also facilitates rapid charging and discharging along three-dimensional heat conductive networks, and confines the melted ET. Compared with neat ET, the copper foam-templated composites have reduced the supercooling degree by ~60 °C and improved thermal conductivity by more than 5 times, which in turn lead to a large latent-heat releasing percentage of 85.8% and a high heat-extraction efficiency of 94.2%. We demonstrate that such composites can be used for high-efficiency, medium-temperature, form-stable, direct solar-thermal energy harvesting, and the harvested heat can be readily converted into electricity to power small devices.
研究领域:
材料科学
·
能量存储
·
太阳能
·
热能工程
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）