Photodegradation of 17α-ethynylestradiol in nitrate aqueous solutions

Dong Ren,Tingting Bi,Shumei Gao,Xukun Li,Bin Huang,Xuejun Pan 대한환경공학회 2016 Environmental Engineering Research Vol.21 No.2

17α-Ethynylestradiol (Ee₂) has gotten growing concerns due to its widely detected in the environment and high estrogenic potency. However, the knowledge on the photochemical behaviors of Ee₂ in natural waters is still limited. Herein, the photodegradation and estrogenic potency variation of Ee₂ induced by nitrate were studied using a sunlight simulator consisted by a 300 W medium pressure mercury lamp and 290 nm cut-off filters. It was found that Ee₂ could be photodegraded at a rate of 0.0193 h-1 in pure aqueous solutions, and the photodegradation of Ee₂ could be significantly promoted by nitrate. The photodegradation removal rate of Ee₂ was increased from 9% in Milli-Q water to 85% in 2.0 mM nitrate solutions. Reactive species scavenging experiments demonstrated that the photogenerated HO? contributed about 55% to Ee₂ degradation. Fe(III), Cl- and dissolved humic acid (DHA) could inhibit the photodegradation of Ee₂ by competing the incident light and photogenerated HO?, while HCO₃ - had no influence on Ee₂ photodegradation. Ee₂ was determined to be phototransformed into organic chemicals without estrogenic potency by GC-MS and MCF-7 cell proliferation toxicity tests. These findings could extend our knowledge on the photochemical behaviors of steroid estrogens and provide information for ecological risk assessment.

Review and Evaluation of Hand-Arm Coordinate Systems for Measuring Vibration Exposure, Biodynamic Responses, and Hand Forces

Dong, Ren G.,Sinsel, Erik W.,Welcome, Daniel E.,Warren, Christopher,Xu, Xueyan S.,McDowell, Thomas W.,Wu, John Z. Occupational Safety and Health Research Institute 2015 Safety and health at work Vol.6 No.3

The hand coordinate systems for measuring vibration exposures and biodynamic responses have been standardized, but they are not actually used in many studies. This contradicts the purpose of the standardization. The objectives of this study were to identify the major sources of this problem, and to help define or identify better coordinate systems for the standardization. This study systematically reviewed the principles and definition methods, and evaluated typical hand coordinate systems. This study confirms that, as accelerometers remain the major technology for vibration measurement, it is reasonable to standardize two types of coordinate systems: a tool-based basicentric (BC) system and an anatomically based biodynamic (BD) system. However, these coordinate systems are not well defined in the current standard. Definition of the standard BC system is confusing, and it can be interpreted differently; as a result, it has been inconsistently applied in various standards and studies. The standard hand BD system is defined using the orientation of the third metacarpal bone. It is neither convenient nor defined based on important biological or biodynamic features. This explains why it is rarely used in practice. To resolve these inconsistencies and deficiencies, we proposed a revised method for defining the realistic handle BC system and an alternative method for defining the hand BD system. A fingertip-based BD system for measuring the principal grip force is also proposed based on an important feature of the grip force confirmed in this study.

Review and Evaluation of Hand–Arm Coordinate Systems for Measuring Vibration Exposure, Biodynamic Responses, and Hand Forces

Ren G. Dong,Erik W. Sinsel,Daniel E. Welcome,Christopher Warren,Xueyan S. Xu,Thomas W. McDowell,John Z. Wu 한국산업안전보건공단 산업안전보건연구원 2015 Safety and health at work Vol.6 No.3

The hand coordinate systems for measuring vibration exposures and biodynamic responses have been standardized, but they are not actually used in many studies. This contradicts the purpose of the standardization. The objectives of this study were to identify the major sources of this problem, and to help define or identify better coordinate systems for the standardization. This study systematically reviewed the principles and definition methods, and evaluated typical hand coordinate systems. This study confirms that, as accelerometers remain the major technology for vibration measurement, it is reasonable to standardize two types of coordinate systems: a tool-based basicentric (BC) system and an anatomically based biodynamic (BD) system. However, these coordinate systems are not well defined in the current standard. Definition of the standard BC system is confusing, and it can be interpreted differently; as a result, it has been inconsistently applied in various standards and studies. The standard hand BD system is defined using the orientation of the third metacarpal bone. It is neither convenient nor defined based on important biological or biodynamic features. This explains why it is rarely used in practice. To resolve these inconsistencies and deficiencies, we proposed a revised method for defining the realistic handle BC system and an alternative method for defining the hand BD system. A fingertip-based BD system for measuring the principal grip force is also proposed based on an important feature of the grip force confirmed in this study.

Spatiotemporal Variations and Possible Sources of Ambient PM10 from 2003 to 2012 in Luzhou, China

Dong Ren,Youping Li,Hong Zhou,Xiaoxia Yang,Xiaoman Li,Xuejun Pan,Bin Huang 대한환경공학회 2014 Environmental Engineering Research Vol.19 No.4

Descriptive statistics methods were used to study the spatiotemporal variations and sources of ambient particulate matter (PM10) in Luzhou, China. The analyzed datasets were collected from four national air quality monitoring stations: Jiushi (S1), Xiaoshi (S2), Zhongshan (S3), Lantian (S4) over the period of 2003-2012. This city was subjected serious PM10 pollution, and the long-term annual average PM10 concentrations varied from 76 to 136 μg/m3. The maximum concentration was more than 3-fold of the annual average (40 μg/m3) issued by EPA-China for the ambient air quality. General temporal pattern was characterized by high concentrations in winter and low concentrations in summer, and general spatial gradient was in the reduction order of S2 > S4 > S3 > S1, which were both due to different particulate contributors and special meteorological conditions. The source apportionment indicated that vehicular emissions, road dusts, coal burning and chemical dusts were the major contributors of the identified PM10 pollution, and the vehicular emissions and the road wear re-suspended particles dominated the heavy PM10 pollution in recent years. Two other potential sources, agricultural and celebration activities could decrease the air quality in a short term. Finally, some corresponding suggestions and measures were provided to improve the air quality.

A type of modified BFGS algorithm with any rank defects and the local Q-superlinear convergence properties

Ren-dong Ge,Zun-Quan Xia,GuoQiang 한국전산응용수학회 2006 Journal of applied mathematics & informatics Vol.22 No.1-2

A modified BFGS algorithm for solving the unconstrained optimization, whose Hessian matrix at the minimum point of the convex function is of rank defects, is presented in this paper.The main idea of the algorithm is first to add a modified term to the convex function for obtain an equivalent model, then simply the model to get the modified BFGS algorithm. The superlinear convergence property of the algorithm is proved in this paper. To compared with the Tensor algorithms presented by R. B. Schnabel (seing [4],[5]), this method is more efficient for solving singular unconstrained optimization in computing amount and complication.

공공미술의 현황과 사례 연구

이동인 ( Dong Ren Li ) 전남대학교 예술연구소 2015 藝術論集 Vol.16 No.-

과거의 공공미술은 공공성보다는 미술에 초점을 두었으며, 공동체보다는 예술가에 중심을 두었지만 현재의 공공미술은 결과보다는 과정을 중시하고 주민의 참여를 통한 소통을 필수적인 요소로 받아들여 하드웨어 중심에서 소프트웨어 중심으로 변화하고 있는 실정이다. 본 논문은 공공미술의 현황과 사례에 대한 연구로서 국내에서 2000년대 이후 현재까지 각각의 공공미술 프로젝트들이 서로 다른 개념과 형태를 가지고 현재까지 어떻게 이루어 졌는지를 알아봄으로써 현재 공공미술의 현황을 살펴본다. 그리고 국내 국가사업으로서의 공공미술과 민간단체에 의한 공공미술 프로젝트의 사례분석을 통해 현재 공공미술 프로젝트의 긍정적인 부분과 문제점을 동시에 짚어 봄으로서 앞으로의 방향을 제시하고자 한다. 따라서 본 논문은 국내 공공미술 프로젝트들을 논의하고 공공미술이 단지 예술가에 의한 활동만이 아니라 공공미술 자체가 사회 속에서 주민과의 실질적인 소통의 구심점이 되어야 한다는 방향성을 모색한다는데 의의를 갖는다. 궁극적으로 공공미술 프로젝트 자체에 대한 사회적 시각을 변화시키고 공공미술이 현 사회속에서 원활한 흐름과 소통을 가능하게 할 수 있는 변화에 대해 논의하는데 중심을 두고 있다. In the past, Public Art focused on art rather than public nature, and an artist rather than community. It is more concerned with the process than the result with participate of people as the essential factor, so it changes from hardware to software. This study is about current status and case study of public art and by researching how each public art project is formed with varying concept and shape after 2000 internally. Through case analysis of public art project as a private enterprise and as a national enterprise, it presents a future direction with showing negative and positive parts of current public art project. So this paper is discussed not only activities led by the artists but also public art itself have center of the actual communication with people in society. Ultimately it puts stress on changes on the view that makes possibility of communication and smooth circulation in public art at present.

Workload Characterization on a Cloud Platform: An Early Experience

Zujie Ren,Jinxiang Dong,Yongjian Ren,Renjie Zhou,Xindong You 보안공학연구지원센터 2016 International Journal of Grid and Distributed Comp Vol.9 No.6

Understanding the characteristics of cloud workloads is the key to making optimal configuration decisions and improving the system throughput. However workload characterization of cloud, especially in a large-scale production environment, has not been well studied yet. To gain insights on cloud workloads, we collected a one-week workload trace from a 100-node cloud cluster which hosts 1082 virtual machines. We characterized the workload at the granularity of virtual machines and physical nodes, respectively. We concluded with a set of meaningful observations. The results of workload characterization are representative and generally consistent with cloud cluster for public IaaS service providers, which can help other researchers and engineers understand the performance and VM characteristics of the cloud in their production environments.

A TYPE OF MODIFIED BFGS ALGORITHM WITH ANY RANK DEFECTS AND THE LOCAL Q-SUPERLINEAR CONVERGENCE PROPERTIES

Ge, Ren-Dong,Xia, Zun-Quan,Qiang, Guo 한국전산응용수학회 2006 Journal of applied mathematics & informatics Vol.22 No.1

A modified BFGS algorithm for solving the unconstrained optimization, whose Hessian matrix at the minimum point of the convex function is of rank defects, is presented in this paper. The main idea of the algorithm is first to add a modified term to the convex function for obtain an equivalent model, then simply the model to get the modified BFGS algorithm. The superlinear convergence property of the algorithm is proved in this paper. To compared with the Tensor algorithms presented by R. B. Schnabel (seing [4],[5]), this method is more efficient for solving singular unconstrained optimization in computing amount and complication.

A New Monoterpene Glycoside and Antibacterial Monoterpene Glycosides from Paeonia suffruticosa

An, Ren-Bo,Kim, Hyun-Chul,Lee, Sung-Hee,Jeong, Gil-Saeng,Sohn, Dong-Hwan,Park, Hyun,Kwon, Dong-Yeul,Lee, John-Hwa,Kim, Youn-Chul The Pharmaceutical Society of Korea 2006 Archives of Pharmacal Research Vol.29 No.10

Antibacterial activity-guided fractionation of the $CHCl_3-MeOH$ (1:1) extract of Paeonia suffruticosa root bark furnished three monoterpene glycosides, 6-O-vanillyoxypaeoniflorin (1), mudanpioside-H (2), and galloyl-oxypaeoniflorin (3). Of the isolated compounds, compound 1 is a new compound. All isolated compounds showed broad, but moderate, antibacterial activity with minimum inhibitory concentration (MIC) values in the range of 100 to $500\;{\mu}g/mL$ against eighteen pathogenic microorganisms of concern for public health or zoonosis.

Superamphiphobic Silicon-Nanowire-Embedded Microsystem and In-Contact Flow Performance of Gas and Liquid Streams

Ko, Dong-Hyeon,Ren, Wurong,Kim, Jin-Oh,Wang, Jun,Wang, Hao,Sharma, Siddharth,Faustini, Marco,Kim, Dong-Pyo American Chemical Society 2016 ACS NANO Vol.10 No.1

<P>Gas and liquid streams are invariably separated either by a solid wall or by a membrane for heat or mass transfer between the gas and liquid streams. Without the separating wall, the gas phase is present as bubbles in liquid or, in a microsystem, as gas plugs between slugs of liquid. Continuous and direct contact between the two moving streams of gas and liquid is quite an efficient way of achieving heat or mass transfer between the two phases. Here, we report a silicon nanowire built-in microsystem in which a liquid stream flows in contact with an underlying gas stream. The upper liquid stream does not penetrate into the lower gas stream due to the superamphiphobic nature of the silicon nanowires built into the bottom wall, thereby preserving the integrity of continuous gas and liquid streams, although they are flowing in contact. Due to the superamphiphobic nature of silicon nanowires, the microsystem provides the best possible interfacial mass transfer known to date between flowing gas and liquid phases, which can achieve excellent chemical performance in two-phase organic syntheses.</P>