Adsorption and separation of lignin-based aromatic aldehydes using macroporous resins

Zhen Wu,Lei Hu,Ning Xu,Benlin Dai,Jiaxing Xu 한국화학공학회 2015 Korean Journal of Chemical Engineering Vol.32 No.7

Lignin-based aromatic aldehydes (p-hydroxybenzaldehyde, vanillaldehyde and syringaldehyde) have wide applications in flavoring. However, their separation using chromatographic methods has not been explored. We studied the adsorption and desorption behaviors of aromatic aldehydes on macroporous resins and four macroporous resins X-5, CAD-40, AB-8 and D101 were screened for separation of aromatic aldehydes. The results demonstrated that X-5 showed the highest adsorption and desorption capacities. The adsorption capacities for p-hydroxybenzaldehyde, vanillaldehyde and syringaldehyde on X-5 were 33.5mg/g, 46.6mg/g and 47.0mg/g at 20 oC, respectively, higher than that of CAD-40, AB-8 and D101. Adsorption isotherms of aromatic aldehydes on X-5 were confirmed to fit to Freundlich equation which was calculated by lnQe=0.6933lnCe+6.788, lnQe=0.7031lnCe+7.7358 and lnQe=0.7107lnCe+ 8.2412 for p-hydroxybenzaldehyde, vanillaldehyde and syringaldehyde, respectively. The results of dynamic adsorption and desorption experiments demonstrated that 50% (v/v) ethanol solution was an effective elution solvent for aromatic aldehydes. The maximum concentration of the three kinds of aromatic aldehydes in eluent reached 3.74 g/L, 5.44 g/L and 7.03 g/L, which indicated that the elution process was also an effective enrichment process for sorbate.

Thermodynamic analysis of a novel adiabatic compressed air energy storage system with water cycle

Zhen Xu,Haiyang Yang,Yingchun Xie,Jinchi Zhu,Chaoqun Liu 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.6

A novel water cycle compressed air energy storage system (WC-CAES) is proposed to improve the energy storage density (ESD) and round trip efficiency (RTE) of A-CAES. The new system decreases electricity consumption by recovering and reusing the hydraulic pressure of water. The thermodynamic characteristics of WC-CAES are evaluated by energy and advanced exergy analysis method. When the air storage pressure of WC-CAES is equal to the minimum storage pressure of A-CAES (4.2 MPa), the ESD and generalized storage density increase by 5.85 % and 32.41 %, respectively. When the air storage pressure increases to the same level as A-CAES (7.2 MPa), ESD and generalized storage density increase by 112 % and 162 %, respectively. In addition, the RTE increases by 1.6 % when the air storage pressure is 4.2 MPa. WC-CAES is therefore verified to be an effective way to improve the performance of conventional A-CAES.

Preparation and characterization of poly(dimethylsiloxane)-polytetrafluoroethylene (PDMS-PTFE) composite membrane for pervaporation of chloroform from aqueous solution

Zhen-Liang Xu,De Sun,Bing-Bing Li 한국화학공학회 2013 Korean Journal of Chemical Engineering Vol.30 No.11

Hydrophobic polydimethylsiloxane - polytetrafluoroethylene (PDMS-PTFE) flat-sheet membranes for pervaporation (PV) of chloroform from aqueous solution were successfully fabricated by solution casting method. The structures and the performance of the membranes was characterized by X-ray diffraction (XRD), scanning electron microscope combined with energy dispersive X-ray spectroscopy (SEM-EDXS), Fourier transform infrared spectroscopy (FT-IR), thermal gravimetric analysis (TGA) and the tests of contact angle and mechanical properties. The adding of PTFE particles (<4 μm) in the PDMS matrix enhanced the crystallinity, hydrophobicity, mechanical strength and thermal stability of the membranes. The examinations showed that the PTFE filled PDMS membranes exhibited striking advantages in flux and separation factor as compared with unfilled PDMS membranes. All the filled PDMS membranes with different PTFE content showed excellent PV properties for the separation of chloroform from water. When the content of the PTFE additive in PDMS composite membrane was 30 wt%, membrane performance was the best at feed temperature 50 oC and permeate-side vacuum 0.101MPa. For the 30% PTFE-PDMS membrane, with the increase of the feed temperature from 30 to 60 oC, the total, water and chloroform fluxes as well as the separation factor increased,the apparent activation energy (ΔEa) of total, chloroform and water were 21.08, 66.65 and 11.49 KJ/mol, respectively,with an increase of chloroform concentration in the feed from 50 to 950 ppm, total, water and chloroform fluxes increased but the separation factor decreased.

원격탐사자료를 이용한 인공구조물 건설에 의한 군산 유부도 조간대의 지형변화 및 표면특성에 관한 연구

( Zhen Xu ),김덕진 ( Duk Jin Kim ),김승희 ( Seung Hee Kim ) 대한원격탐사학회 2013 大韓遠隔探査學會誌 Vol.29 No.1

20세기 후반부터 유부도 주위에서 하구언 축조 등 비교적 큰 규모의 간척사업들이 진행되었다. 이러한 간척사업의 시작으로 인공구조물들이 연안에 축조됨에 따라 주변 해역의 해류, 조위 및 조류의 변화를 야기하여 퇴적 및 침식으로 인한 연안지형의 변화가 예상된다. 따라서 이 연구에서는 유부도 조간대를 포함하는 Landsat TM/ETM+자료를 1998년부터 2012년까지 획득한 후 waterline 기법을 적용하여 인공구조물 축조에 의한 지형변화를 탐지하였다. 그 결과 유부도의 동쪽, 북동쪽, 서쪽 조간대에서 주로 퇴적이 일어났으며 그 면적이 약 4.5 km2 이상 되었다. 한편, RADARSAT-2의 완전편파 SAR자료에 Freeman-Durden decomposition을 적용하여 퇴적이 뚜렷이 일어난 지역에 대한 산란특성을 분석하였다. 그 결과 동쪽 퇴적지역은 서쪽 및 북동쪽의 퇴적지역과는 다른 산란특징이 관찰되었으며, 이는 퇴적환경의 차이로 인해 다른 종류의 퇴적물이 퇴적되어 발생한 것으로 여겨진다. Large-scale coastal construction projects, such as land reclamation and dykes, were constructed from the late twentieth century in Yoobu-Do region. Land reclamation combined with the dynamics of tidal currents may have accelerated local sedimentation and erosion resulting in rapid reformation of coastal topography. This study presents the results of the topography changes around Yoobu-Do by large-scale coastal constructions using time-series waterline extraction technique of Landsat TM/ETM+data acquired from 1998 to 2012. Furthermore, the Freeman-Durden decomposition was applied to fully polarimetric RADARSAT-2 SAR data in order to analyze the scattering mechanisms of the deposited surface. According to the case study, the deposition areas were over 4.5 km2 and distributed in the east, northeast, and west of Yoobu-Do. In the eastern deposition area, it was found that the scattering mechanism was difference from other deposition areas possibly indicating that different types of soil were deposited.

GIS를 이용한 기후변화에 따른 산사태 취약성 평가

Xu Zhen,곽한빈(Kwak, Hanbin),이우균(Lee, Woo-Kyun),박태진(Park, Taejin),권태협(Kwon, Tae-Hyub),박선민(Park, Sunmin) 한국기후변화학회 2011 한국기후변화학회지 Vol.2 No.1

Mortality Characteristic and Prediction of Nasopharyngeal Carcinoma in China from 1991 to 2013

Xu, Zhen-Xi,Lin, Zhi-Xiong,Fang, Jia-Ying,Wu, Ku-Sheng,Du, Pei-Ling,Zeng, Yang,Tang, Wen-Rui,Xu, Xiao-Ling,Lin, Kun Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.15

Background: To analyze the mortality distribution of nasopharyngeal carcinoma in China from 1991 to 2013, to predict the mortality in the ensuing five years, and to provide evidence for prevention and treatment of nasopharyngeal carcinoma. Materials and Methods: Mortality data for Nasopharyngeal Carcinoma in China from 1991 to 2013 were used to describe its epidemiological characteristics, such as the change of the standardized mortality rate, sex and age differences, urban-rural differences. Trend-surface analysis was used to study the geographical distribution of the mortality. Curve estimation, time series, gray modeling, and joinpoint regression were used to predict the mortality for the ensuing five years in the future. Results: In China, the standardized mortality rate of Nasopharyngeal Carcinoma increased with time from 1996, reaching the peak values of $1.45/10^5$ at the year of 2002, and decreased gradually afterwards. With males being 1.51 times higher than females, and the city had a higher rate than the rural during the past two decades. The mortality rate increased from age 40. Geographical analysis showed the mortality rate increased from middle to southern China. Conclusions: The standardized mortality rate of Nasopharyngeal Carcinoma is falling. The regional disease control for Nasopharyngeal Carcinoma should be focused on Guangdong province of China, and the key targets for prevention and treatment are rural men, especially after the age of 40. The mortality of Nasopharyngeal Carcinoma will decrease in the next five years.

Adaptation of murine anaplastic thyroid cancer cell line from hybrid to inbred C57BL/6 mice

Zhen Xu,Seong Yun Ha,Hyo Shik Shin,Minjun Kim,Su-jin Kim,Jae-Kyung Won,Seong-Hyeon Kim,Sun Wook Cho,Kyu Eun Lee 한국실험동물학회 2021 한국실험동물학회 학술발표대회 논문집 Vol.2021 No.7

Background: Immuno-competent mouse model is indispensable for the study of tumor immune microenvironment. TBP-3743 cell line is derived from anaplastic thyroid cancer arising in immune-competent B6129SF1 mouse with thyroid-specific BrafV600E/WT and deletion of Trp53. Aim of this study is to adapt TBP-3743 cell line to C57BL/6 stain, widely used mouse strain which has same MHC haplotype with that of B6129SF1. Methods: TBP-3743 cell line was subcutaneously injected into C57BL/6 mice. The mouse with the rapidest tumor growth was sacrificed for primary culture and the cultured cells were injected into naive C57BL/6 mice. This serial of processes, called adaptation, has been performed three times. The concentration-dependent growth analysis is performed by comparing the tumor growth of 1x107-injected and 5x106-injected group. Furthermore, Original TBP-3743 cells and adapted TBP-3743 cells were treated with BRAFV600E inhibitor(PLX-4032, 1uM) in vitro and cell proliferation was measured by luminometric detection. For Immunotherapy, mice were treated 10mg/kg of PLX-4032 on daily basis, 15mg/kg of anti-CD47 every other day, 10mg/kg of anti-PD-L1 every other day Results: In the course of adaptation, the lag phage of tumor growth shortened and tumor growth rate had dramatically increased. In vitro growth of Both TBP-3743 and adapted TBP-3743(TBP-3743B6) were effectively BRAFV600E-selective inhibitor (PLX-4032). In vivo treatment of PLX-4032 with anti-CD47 and/or anti-PD-L1 reduced tumor volume in mice injected with TBP-3743B6 and prolonged their survival compared to control Conclusions: We established a novel immunocompetent murine anaplastic thyroid cancer model available in C57BL/6 inbred mice. TBP-3743B6 grows rapidly and stably in immunocompetent C57BL/6 mice. This mouse model can save unnecessary time, cost and labor for the research of tumor immune microenvironment. Also, this newly established cell line will be a useful resource to expand the feasibility of basic research as well as drug screening for potential therapeutic effects on anaplastic thyroid cancer.

Investigation of One-dimensional Consolidation of Fractional Derivative Model for Viscoelastic Saturated Soils Caused by the Groundwater Level Change

Xu-Bing Xu,Zhen-Dong Cui 대한토목학회 2022 KSCE Journal of Civil Engineering Vol.26 No.12

The Fractional calculus theory is introduced into the Merchant model to study the mechanical characteristics of saturated soils. Laplace transform is applied to the 1D consolidation and the fractional derivative Merchant model constitutive equations of saturated soils. In the transform domain, the analytical solutions of effective stress and settlement are obtained by solving the simultaneous equation. The Crump’s method is used to the numerical inversion of Laplace transform, and the semi-analytical solution of the one-dimensional consolidation is obtained. A series of parameters, such as the fractional order, compression modulus, coefficient of viscosity, permeability coefficient and the variation models of groundwater level, are studied. Considering the continuity conditions, the 1D consolidation equation of single-layer saturated soil is generalized to multi-layer soils, and then the influence of different boundaries on several kinds of consolidation behavior was analyzed.

以“情”为线,以“史”为轴:朵拉短篇小说实践的赓续与新变

徐榛(Zhen Xu) YIXIN 출판사 2023 Journal of Humanities and Social Sciences Vol.1 No.1

SYNTHESIS OF CALCIUM OXALATE ASSEMBLY STRUCTURE AND CONVERSION

ZHI-ZHEN XU,JIN-KU LIU,QING-SHENG WU 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2007 NANO Vol.2 No.2

The conversion from one assembly structure to other composite assembly structures is valuable to both theoretical research and actual application in the nano/micromaterials science. In this paper, firstly, the flower-like calcium oxalate assembly structure was synthesized using a supramolecule template; then, through a facile process, the calcium oxalate was converted to a sphere-cluster-like core/shell CaC2O4/CaWO4 nanocomposite assembly structure. The converted product remained the basic structure of original product, and possessed some new optical properties such as fluorescence, etc.