Robust Unit Commitment with Virtual Synchronous Renewables

Zhang Wei-Chao,Sheng Wanxing,Duan Qing,Sha Guanglin,Zhang Yao,Huang Hanyan,Yan Xiangwu 대한전기학회 2022 Journal of Electrical Engineering & Technology Vol.17 No.6

With the increasing penetration of renewable energy sources and the consequent displacement of synchronous generators, the frequency stability of power systems deteriorates since RESs cannot participate in active power and frequency control. By emulating the outer characteristics of SGs and deloading a controllable margin, RESs can also keep headroom and provide frequency responses. This paper focuses on incorporating virtual synchronous renewables into the unit commitment to optimize the joint scheduling of energy production and spinning reserves. First, based on the interval representation of renewable uncertainty, the renewable output is decomposed into the stochastic and dispatchable portions. The dispatchable portion, defi ned as VSRs, can keep deterministic regulation headroom and participate in power balance regulation. Second, a robust security-constrained unit commitment model is proposed to achieve optimal scheduling in face of multiple uncertainties. The fl exibility of the pumped-storage hydro station is also considered. Third, the solution strategies which linearize the nonlinear terms in the objective function and constraints are introduced. Finally, the correctness and eff ectiveness of the robust unit commitment model are tested and verifi ed in the modifi ed 39-bus system.

In vitro evaluation of 9-(2-phosphonylmethoxyethyl)adenine ester analogues, a series of anti-HBV structures with improved plasma stability and liver release

Sha Liao,Shi-Yong Fan,Qin Liu,Chang-Kun L,Jia Chen,Jing-Lai Li,Zhi-Wei Zhang,Zhen-Qing Zhang,Bo-Hua Zhong,Jian-Wei Xie 대한약학회 2014 Archives of Pharmacal Research Vol.37 No.11

Chronic hepatitis B virus (HBV) infection maylead to liver cirrhosis and hepatocellular carcinoma, butfew drugs are available for its treatment. Acyclic nucleosidephosphonates (ANPs) have remarkable antivirusactivities but are not easily absorbed from the gastrointestinaltract and accumulate in the kidneys, resulting innephrotoxicity. Therefore, there is a need to find effectiveliver site-specific prodrugs. The dipivaloyloxymethyl esterof 9-(2-phosphonylmethoxyethyl)adenine (PMEA)—adefovirdipivoxil (ADV)—is a first-line therapy drug forchronic hepatitis B with a low therapeutic index because ofrenal toxicity and low hepatic uptake. In this study, a seriesof PMEA derivatives were synthesized to enhance plasmastability and liver release. The metabolic stability of ADV(Chemical I) and its two analogues (Chemicals II and III)was evaluated in rat plasma and liver homogenate in vitro. An ion-pair reverse-phase HPLC–UV method and a hybridion trap and high-resolution time-of-flight mass spectrometry(LC-IT-TOF-MS) were used to evaluate the degradationrate of the analogues and to identify their intermediatemetabolites, respectively. Chemicals I and II were hydrolyzedby cleavage of the C–O bond to give monoesters. Sufficient enzymatic activation in the liver homogenatethrough a relatively simple metabolic pathway, in additionto a favorable stability profile in rat plasma, made ChemicalII an optimal candidate. Next, six analogues based onthe structure of Chemical II were synthesized and evaluatedin plasma and liver homogenate. Compared toChemical II, these compounds generated less active PMEAlevels in rat liver homogenate. Therefore, chemical modificationof Chemical II may lead to new promising PMEAderivatives with enhanced plasma stability and liveractivation.

중국기업 최고경영자 보상과 성과 간의 관계와 기업 내 · 외부 불확실성의 조절효과에 대한 연구

장사(Sha Zhang),유재욱(Jaewook Yoo) 대한경영학회 2015 大韓經營學會誌 Vol.28 No.5

Rapid Preparation of Ultrafine BaSO3 by SO2 Storage Material

Fei Zhang,Feng Sha,Xianshu Qiao,Tianxiang Zhao,Bo Guo,Jianbin Zhang 대한화학회 2017 Bulletin of the Korean Chemical Society Vol.38 No.1

In this work, a green and efficient process was developed for the preparation of ultrafine BaSO3 with layered nanostructure surface via the reaction of BaCl2 with a SO2 storage material (SO2SM) at room temperature. The absorption of SO2 with equimolar ethylenediamine (EDA) and ethylene glycol (EG) afforded SO2SM, which not only offered alkyl sulfite but also released EDA and EG that served as efficient surfactants to promote the formation of BaSO3 with spherical morphology and porous structure in the process of synthesis of ultrafine BaSO3. The factors affecting the morphology and size of BaSO3 particle were assessed by investigating the effects of SO2SM concentration, BaCl2 concentration, stirring time and speed. It was found that a higher SO2SM concentration led to a higher degree of supersaturation, and the particle size of BaSO3 could be reduced by increasing SO2SM concentration. Moreover, under the identified optimal reaction conditions, ultrafine BaSO3 was obtained with an average diameter of 450 nm. In addition, a plausible formation process of BaSO3 was proposed to explain the observed reaction results. Overall, the developed process in this work provides an efficient method for the capture, utilization, and conversion of SO2 into a valuable chemical.

Rheinic acid ameliorates radiation‑induced acute enteritis in rats through PPAR‑γ/NF‑κB

Haixia Sha,Yu Gu,Weixing Shen,Li Zhang,Fei Qian,Yudong Zhao,Haixiao Li,Ting Zhang,Weimin Lu 한국유전학회 2019 Genes & Genomics Vol.41 No.8

Background Acute radiation enteritis (ARE), a common complication of intestinal caused by abdominal and pelvic radiation therapy. Rheinic acid is a major active ingredient derived from Rhubarb. Rhubarb could suppress inflammation, tumor, fibrosis oxidative damage. However, RA as the main active component and extract monomer of Rhubarb, the pharmacological activity and the underlying molecular mechanism on various diseases has not yet been revealed. Objective To determine the potential role of rheinic acid (RA) in ameliorating inflammation of rats with acute radiation enteritis (ARE), and explore the underlying mechanism. Methods ARE rat model was established by irradiated with single-dose 10 Gy X-rays at a rate of 0.62 Gy/min to the abdomen. The rats were executed after orally administered with Rheinic acid 7 days and used in the subsequent experiments. Body weight, fecal characteristics and bloody of rats were used to assess the disease activity index. Histological analysis of the jejunum and colon were evaluated using H&E staining. The pro-inflammatory cytokines levels were measured by immunohistochemistry and ELISA. The levels of nitric oxide (NO), malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione (GSH) were also determined. The mRNA and protein expression were examined by real-time polymerase chain reaction (qRT-PCR) and western blot, respectively. Results Rheinic acid promoted intestinal functional recovery, and ameliorated intestinal damage and bloody stool in ARE rats. Rheinic acid strongly decreased the levels of tumor necrosis factor-α, interleukin-1, interleukin-6, NO, and MDA, whereas increased levels of anti-oxidants, SOD and GSH. Moreover, the expression of apoptosis-related proteins, cleaved caspase-3 and cleaved poly (ADP-ribose) polymerase (PARP), were decreased with RA treatment. Further study indicated that PPAR-γ was activated and thereby NF-κB and p38 MAPK signaling pathway were suppressed after rheinic acid treatment. Conclusion Rheinic acid could ameliorate acute radiation enteritis and the underlying molecular mechanism is, at least partially, through PPAR-γ/NF-κB and p38 MAPK/JNK pathways.

A novel CCU approach of CO2 by the system 1,2-ethylenediamine+1,2-ethylene glycol

Jianbin Zhang,Bo Guo,Tianxiang Zhao,Feng Sha,Fei Zhang,Qiang Li 한국화학공학회 2016 Korean Journal of Chemical Engineering Vol.33 No.6

As a new, effective CO2 fixation system, 1,2-ethylenediamine and 1,2-ethylene glycol (EDA+EG) can efficiently activate CO2 and directly convert it into a novel CO2-storage material (CO2SM) with 46.3% yield. The aqueous CO2SM solution can react with Ca(OH)2-saturated limpid solution to generate morphology-controllable CaCO3 microparticles with additional CO2 bubbling and Ca(OH)2. Additionally, the aqueous EDA+EG solution could be recycled multiple times without significant loss of CO2 capturing and releasing capabilities.

Numerical optimization of transmission bremsstrahlung target for intense pulsed electron beam

Xiao Yu,Jie Shen,Shijian Zhang,Jie Zhang,Nan Zhang,Ivan Sergeevich Egorov,Sha Yan,Chang Tan,Gennady Efimovich Remnev,Xiaoyun Le 한국원자력학회 2022 Nuclear Engineering and Technology Vol.54 No.2

The optimization of a transmission type bremsstrahlung conversion target was carried out with MonteCarlo code FLUKA for intense pulsed electron beams with electron energy of several hundred keV formaximum photon fluence. The photon emission intensity from electrons with energy ranging from300 keV to 1 MeV on tungsten, tantalum and molybdenum targets was calculated with varied targetthicknesses. The research revealed that higher target material element number and electron energy leadsto increased photon fluence. For a certain target material, the target thickness with maximum photonemission fluence exhibits a linear relationship with the electron energy. With certain electron energy andtarget material, the thickness of the target plays a dominant role in increasing the transmission photonintensity, with small target thickness the photon flux is largely restricted by low energy loss of electronsfor photon generation while thick targets may impose extra absorption for the generated photons. Thespatial distribution of bremsstrahlung photon density was analyzed and the optimal target thicknessesfor maximum bremsstrahlung photon fluence were derived versus electron energy on three targetmaterials for a quick determination of optimal target design

Associations of hypoxia inducible factor-1a gene polymorphisms with susceptibility to digestive tract cancers: a case–control study and meta-analysis

Zhi-Hai Ni,Xian-Jun Liang,Jing-Gang Mo,Yi Zhang,Jian-Hua Liang,Yu-Sha Yang,Yong Zhou,Zhao-Hua Li,Jian-Liang Zhang,Yin-Lu Ding,Peng Zhang,Jin-Qing Wang 한국유전학회 2015 Genes & Genomics Vol.37 No.11

We aim to investigate the correlations of hypoxia inducible factor-1a (HIF-1a) C1772T (rs11549465) and G1790A (rs11549467) gene polymorphisms with digestive tract cancers. A sum of 267 digestive tract cancers patients were hospitalized in Taizhou Central Hospital of Zhejiang Province as case group between December 2012 and December 2014. Additionally, 275 healthy people who had a physical examination in our hospital at the same time were selected as control group. Polymerase chain reaction-restriction fragment length polymorphism was utilized for detecting allele and genotype frequency of different locus in case and control group. Meta-analysis was performed using Comprehensive Metaanalysis 2.0 (Biostat Inc., Englewood, New Jersey, USA). Our result showed statistical significance only exists in family history of cancer between case and control group (P\0.05). Both C1772T (rs11549465) and G1790A (rs11549467) polymorphisms showed positive correlations with an increasing risk of digestive tract cancers. The frequencies of TT genotype of C1772T (rs11549465) and GA, AA genotypes of G1790A (rs11549467) polymorphisms in case group were evidently higher compared with the controls (all P\0.05). Besides, the comparison of allele and dominant models of HIF-1a C1772T (rs11549465) and G1790A (rs11549467) between two groups showed a significant difference (all P\0.05). Meta-analysis results further confirmed that the onset risk of digestive tract cancers may be improved under allele and dominant models of HIF-1a C1772T (rs11549465) and G1790A (rs11549467) (all P\0.05). Single nucleotide polymorphisms of HIF-1a C1772T (rs11549465) and G1790A (rs11549467) may play a role in development of digestive tract cancers.

중국 기업 구성원의 감성지능, 심리적 주인의식, 일의 의미가 제언행동에 미치는 영향에 관한 연구: 직무열의의 매개효과를 중심으로

ZHANG, RUI,Sun, QiYuan,SHA, CHENGCHENG 부산대학교 중국연구소 2023 Journal of China Studies Vol.26 No.1

With technological development and environmental changes, the resources owned by companies and organizations have been equalized, and the competitive advantage of existing resources has lost relative importance. In this way, companies and organizations must secure excellent talents to secure a continuous competitive advantage. However, in Chinese current human resource management method, the traditional way of simply exchanging goods and services is insufficient to induce voluntary commitment of members, and for those companies and organizations with limited resources, it is difficult to give employees a satisfactory allocation of resources. Therefore, this study aims to explore a method to enhance job enthusiasm that can lead to voluntary commitment of members. As such, this study is to first verify whether the emotional intelligence, psychological ownership, and meaning of work of members of the organization affect job engagement. Next, it is intended to verify whether job engagement affects voice behavior. Finally, it is necessary to understand whether work enthusiasm has mediating effect among emotional intelligence, psychological ownership, meaning of work and voice behavior. Therefore, a self-report survey was conducted on members working in Chinese companies in this study, with a total of 395 copies of the collected questionnaire. SPSS V.22.0 and AMOS V.22.0 statistical software were used for empirical analysis, and other analysis techniques such as frequency analysis, exploratory factor analysis, reliability analysis, confirmatory factor analysis, correlation analysis, structural equation model and other analysis methods were also used. The results of this study can be summarized as follows. First, emotional intelligence, psychological ownership, and the meaning of work have a positive (+) effect on job engagement. Second, job engagement has a positive (+) effect on voice behavior. Third, psychological ownership has a positive (+) effect on voice behavior. Fourth, job engagement has a mediating effect among emotional intelligence, psychological ownership, meaning of work and voice behavior.

Protective effect of Insect tea primary leaf (Malus sieboldii (Regal) Rehd.) extract on H2O2‑induced oxidative damage in human embryonic kidney 293T cells

Zhang Jing,Wang Hong,Yi Sha,Guo Zemei,Huang Yue,Li Weifeng,Zhao Xin,Liu Huazhi 한국응용생명화학회 2020 Applied Biological Chemistry (Appl Biol Chem) Vol.63 No.3

In this study, Insect tea primary leaf (Malus sieboldii (Regal) Rehd.) was used as the research object to investigate the protective effect of Insect tea primary extract (ITPLE) on hydrogen peroxide (H2O2)-induced oxidative damage in human embryonic kidney 293T cells (HEK 293T cells) and the mechanism of action of the main active components. The 3-(4,5-dimethyl-2-thiazolyl)- 2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay was used to determine the toxicity of ITPLE to HEK 293T cells in vitro as well as its protective effect against (H2O2)-induced oxidative damage in HEK 293T cells. In addition, various assay kits were used to measure oxidation-related indicators in HEK 293T cells, and quantitative polymerase chain reaction (qPCR) analysis was used to determine the mRNA expression levels of oxidation-related genes in HEK 293T cells. High performance liquid chromatography (HPLC) analysis was used to characterize active components in ITPLE. The experimental results revealed that the ITPLE had no toxic effect on cells in the range of 0–200 μg/mL, and, in this range, exhibited a concentration-dependent protective effect against H2O2- induced oxidative damage in HEK 293T cells. It was also found that the ITPLE can reduce the malondialdehyde (MDA) level and increase the levels of superoxide dismutase (SOD), glutathione (GSH), glutathione peroxidase (GSH-Px), and catalase (CAT)in oxidative damage HEK 293T cells. The qPCR analysis results also showed that the ITPLE upregulated the mRNA expression levels of SOD, CAT , GSH and GSH-Px in HEK 293T cells damaged by H2O2- induced oxidative stress. The HPLC analysis identified 7 bioactive components in the ITPLE, including neochlorogenic acid, cryptochlorogenic acid, rutin, kaempferin, isochlorogenic acid B, isochlorogenic acid A and hesperidin. This study reveals that ITPLE is rich in active compounds and has good antioxidant effect in vitro, thus it has the potential to be developed into a traditional Chinese medicine and functional drinks.