Calculating Wind Variability Costs with Considering Ramping Costs of Conventional Power Plants

Xuemei Dai,Kaifeng Zhang,Jian Geng,Ying Wang,Kun Yuan 대한전기학회 2019 Journal of Electrical Engineering & Technology Vol.14 No.3

Due to the variability of the wind power, conventional power plants are required to ramp more frequently to mitigate the imbalance of generation and supply, which increase the total cost of power systems. The increase of the cost is termed the “variability cost” of wind power. Generally, it includes the additional ramping cost, reserve cost and fuel cost of conventional plants. In this paper, we propose an alternative scenario construction method to calculate the “variability cost” of wind power from the viewpoint of the power system schedule. Firstly, in the alternative scenario, a new energy proxy with zero wind variability costs is constructed. Then, a unit commitment optimization model considering ramping costs is developed. The operation costs of power systems under two scenarios (alternative one and real one) are calculated and the diff erence between two costs is the variability cost. Furthermore, we apply the proposed method to calculate the variability costs of the wind farm cluster. The simulations show that the variability cost increases with higher penetration and higher variability of wind power. Meanwhile, it is found that the variability cost of the wind farm cluster as a whole is lower than the sum of variability costs of each wind farm.

The biocompatibility and mechanical properties of plasma sprayed zirconia coated abutment

Huang, Zhengfei,Wang, Zhifeng,Yin, Kaifeng,Li, Chuanhua,Guo, Meihua,Lan, Jing The Korean Academy of Prosthodonitics 2020 The Journal of Advanced Prosthodontics Vol.12 No.3

PURPOSE. The aim of this study was to evaluate the clinical performance and reliability of plasma sprayed nanostructured zirconia (NSZ) coating. MATERIALS AND METHODS. This study consisted of three areas of analysis: (1) Mechanical property: surface roughness of NSZ coating and bond strength between NSZ coating and titanium specimens were measured, and the microstructure of bonding interface was also observed by scanning election microscope (SEM). (2) Biocompatibility: hemolysis tests, cell proliferation tests, and rat subcutaneous implant test were conducted to evaluate the biocompatibility of NSZ coating. (3) Mechanical compatibility: fracture and artificial aging tests were performed to measure the mechanical compatibility of NSZ-coated titanium abutments. RESULTS. In the mechanical study, 400 ㎛ thick NSZ coatings had the highest bond strength (71.22 ± 1.02 MPa), and a compact transition layer could be observed. In addition, NSZ coating showed excellent biocompatibility in both hemolysis tests and cell proliferation tests. In subcutaneous implant test, NSZ-coated plates showed similar inflammation elimination and fibrous tissue formation processes with that of titanium specimens. Regarding fatigue tests, all NSZ-coated abutments survived in the five-year fatigue test and showed sufficient fracture strength (407.65-663.7 N) for incisor teeth. CONCLUSION. In this study, the plasmasprayed NSZ-coated titanium abutments presented sufficient fracture strength and biocompatibility, and it was demonstrated that plasma spray was a reliable method to prepare high-quality zirconia coating.

Genome-wide analysis of Gro/Tup1 family corepressors and their responses to hormones and abiotic stresses in maize

Hongyou Li,Kaifeng Huang,Hanmei Du,Hongling Wang,Xin Chen,Shibin Gao,Hailan Liu,Moju Cao,Yanli Lu,Tingzhao Rong,Su-Zhi Zhang 한국식물학회 2016 Journal of Plant Biology Vol.59 No.6

Gro/Tup1 proteins act as negative transcriptional regulators and play crucial roles in many growth and developmental processes in a wide range of organisms. However, our understanding of Gro/Tup1 protein functions in plants is confined to the model plant Arabidopsis. Here, 11 Gro/Tup1 genes, which were characterized by the typical LisH and WD40 repeat domains, were identified in maize through a genome-wide survey. A phylogenetic analysis revealed that maize Gro/Tup1 proteins could be divided into three subfamilies, in which members shared similar protein and gene structures. The predicted maize Gro/Tup1 genes were distributed on seven chromosomes and segmental duplication contributed to their expansion. Many predicted cis-elements associated with hormones, biotic- or abioticstress responses, meristem and seed development, and circadian rhythms, were found in their putative promoter regions. A potential associated protein analysis identified a large number of candidates, including transcription factors, chromatin-modifying enzymes, protein kinases, and ubiquitinconjugating enzymes. An expression profile derived from the RNA-seq data indicated that Gro/Tup1 genes in maize were widely expressed in various organs and tissues. Quantitative real-time PCR revealed that these genes responded to at least one hormone or abiotic stress, either in roots or in shoots. Our study provides useful information on the Gro/Tup1 genes in maize and will facilitate the further functional validation of these genes in growth and development, hormone responses, and biotic- or abiotic-stress resistance.

LncRNA-GAS5/miR-382-3p axis inhibits pulmonary artery remodeling and promotes autophagy in chronic thromboembolic pulmonary hypertension

Feng Xiaona,Wang Kaifeng,Yang Ting,Liu Yanhui,Wang Xiaodong 한국유전학회 2022 Genes & Genomics Vol.44 No.4

Background: We have clarified the role of miR-382-3p in chronic thromboembolic pulmonary hypertension (CTEPH), but what is less clear lies in its upstream regulatory mechanism. Objective: To explore the regulation mechanism of GAS5/miR-382-3p axis on CTEPH. Methods: In vitro, we constructed cell models by treating Pulmonary Artery Smooth Muscle Cells (PASMCs) with platelet-derived growth factor-BB (PDGF-BB). The effects of different concentrations of PDGF-BB on the activity of PASMCs were tested by cell counting kit-8 (CCK-8). The upstream lncRNA of miR-382-3p was screened and confirmed through bioinformatics analysis, RNA pull-down, quantitative reverse transcription polymerase chain reaction (qRT-PCR), dual luciferase reporter gene and RNA immunoprecipitation assays. The effects of GAS5/miR-382-3p axis on the viability, migration, and expressions of autophagy- and angiogenesis-related proteins were confirmed by rescue experiments (CCK-8, wound healing and western blot). In vivo, animal models by perfusing autologous blood vessels, the effects of GAS5 overexpression or silencing on the expressions of miR-382-3p, angiogenesis- and autophagy-related genes, mean pulmonary arterial pressure (mPAP) and pulmonary artery wall were determined by biological signal acquisition system, hematoxylin-eosin staining, qRT-PCR and western blot. Results: PDGF-BB dose-dependently promoted PASMCs viability. XIST and GAS5 expressions in PASMCs were affected by the concentration of PDGF-BB, but only GAS5 can be pulled down by miR-382-3p probe. GAS5 targeted miR-382-3p to inhibit the viability and migration of PAMSCs, mPAP in CTEPH rats, pulmonary artery wall thickening and angiogenesis, and promote autophagy. Conclusions: GAS5/miR-382-3p axis is involved in the regulation of pulmonary artery remodeling and autophagy in CTEPH.

SP0454, A Putative Threonine Dehydratase, Is Required For Pneumococcal Virulence In Mice

WenJuan Yan,Hong Wang,WenChun Xu,KaiFeng Wu,Run Yao,XiuYu Xu,Jie Dong,YanQing Zhang,Wen Zhong,XueMei Zhang 한국미생물학회 2012 The journal of microbiology Vol.50 No.3

Increasing pressure in antibiotic resistance and the requirement for the design of new vaccines are the objectives of clarifying the putative virulence factors in pneumococcal infection. In this study, the putative threonine dehydratase sp0454 was inactivated by erythromycin-resistance cassette replacement in Streptococcus pneumoniae CMCC 31203 strain. The sp0454 mutant was tested for cell growth, adherence, colonization, and virulence in a murine model. The Δsp0454 mutant showed decreased ability for colonization and impaired ability to adhere to A549 cells. However, the SP0454 polypeptide or its antiserum did not affect pneumococcal CMCC 31203 adhesion to A549 cells. The sp0454 deletion mutant was less virulent in a murine intranasal infection model. Real-time RT-PCR analysis revealed significant decrease of the pneumococcal surface antigen A expression in the sp0454 mutant. These results suggest that SP0454 contributes to virulence and colonization, which could be explained in part by modulating the expression of other virulence factors, such as psaA in pneumococcal infection.

Effects of feed intake restriction during late pregnancy on the function, anti-oxidation capability and acute phase protein synthesis of ovine liver

Huan Yang,Ying Wang,Chi Ma,Chuan Sun,Yingchun Liu,Kaifeng Wu,Ming Li,Gerelt Borjigin,Feng Gao 아세아·태평양축산학회 2019 Animal Bioscience Vol.32 No.2

Objective: An experiment was conducted to investigate the effects of feed intake restriction during late pregnancy on the function, anti-oxidation capability and acute phase protein synthesis of ovine liver. Methods: Eighteen time-mated ewes with singleton fetuses were allocated to three groups: restricted group 1 (RG1, 0.18 MJ ME/kg W0.75 d, n = 6), restricted group 2 (RG2, 0.33 MJ ME/kg W0.75 d), n = 6) and a control group (CG, ad libitum, 0.67 MJ ME/kg W0.75 d, n = 6). The feed restriction period was from 90 days to 140 days of pregnancy. Results: The ewe’s body weight, liver weights, water, and protein content of liver in the restricted groups were reduced compared with the CG group (p<0.05), but the liver fat contents in the RG1 group were higher than those of the CG group (p<0.05). The increased hepatic collagen fibers and reticular fibers were observed in the restricted groups with the reduction of energy intake. The concentrations of nonesterified free fatty acids in the RG1 and RG2 groups were higher than those of the CG group with the reduction of energy intake (p<0.05), but there were decreased concentrations of lipoprotein lipase and hepatic lipase in both restricted groups compared with the CG group (p<0.05). In addition, the increased concentrations of β-hydroxybutyric acid, triglycerides, malondialdehyde, total antioxidant capacity and activities of superoxide dismutase activity and catalase were found in the RG1 group, and the concentrations of cholinesterase in the RG1 group were reduced compared with the CG group (p<0.05). For the concentrations of acute phase proteins, the C-reactive protein (CRP) in the RG1 group were reduced compared with the CG group, but there were no differences in haptoglobin relative to the controls (p>0.05). Conclusion: The fat accumulation, increased hepatic fibrosis, antioxidant imbalance and modified synthesis of acute phase proteins were induced in ewe’s liver by maternal malnutrition during late pregnancy, which were detrimental for liver function to accommodate pregnancy.

Pneumococcal wall teichoic acid is required for the pathogenesis of Streptococcus pneumoniae in murine models

Hongmei Xu,Libin Wang,Jian Huang,YanQing Zhang,Feng Ma,Jianmin Wang,WenChun Xu,XueMei Zhang,YiBing Yin,KaiFeng Wu 한국미생물학회 2015 The journal of microbiology Vol.53 No.2

Pneumococcal asymptomatic colonization of the respiratory tracts is a major risk for invasive pneumococcal disease. We have previously shown that pneumococcal wall teichoic acid (WTA) was involved in pneumococcal infection of sepsis and adherence to epithelial and endothelial cells. In this study, we investigated the contribution of pneumococcal WTA to bacterial colonization and dissemination in murine models. The result showed that nasopharynx colonizing D39 bacterial cells have a distinct phenotype showing an increased exposure of teichoic acids relative to medium-grown bacteria. The WTA-deficient mutants were impaired in their colonization to the nasopharynx and lungs, and led to a mild inflammation in the lungs at 36 h post-inoculation. Pretreatment of the murine nares with WTA reduced the ability of wild type D39 bacteria to colonize the nasopharynx. In addition, the WTA-deficient strain was impaired in its ability to invade the blood and brain following intranasal administration. WTA-deficient D39 strain was reduced in C3 deposition but was more susceptible to the killing by the neutrophils as compared with its parent strain. Our results also demonstrated that the WTA enhanced pneumococcal colonization and dissemination independently of the host strains. These results indicate that WTA plays an important role in pneumococcal pathogenesis, both in colonization and dissemination processes.

MECHANICAL PROPERTIES AND OPTIMIZATION ANALYSIS ON BATTERY BOX WITH HONEYCOMB SANDWICH COMPOSITE STRUCTURE

Ying Zhao,Jinyu Shi,Kaifeng Wang,Binlin Wang,Chao He,Xiaogang Deng 한국자동차공학회 2023 International journal of automotive technology Vol.24 No.1

A honeycomb sandwich battery box composed of high-strength steel outer layer, sandwich aluminum alloy honeycomb and inner layer is proposed. Firstly, the expressions of platform stress, ultimate strain and equivalent elastic modulus of ‘Y’ honeycomb cell are derived based on deformation mechanism and energy principle under quasi-static compression, and then the relations among relative density, unit volume energy absorption and thickness coefficient are acquired. Based on above, the optimal thickness coefficient of honeycomb unit cell can be acquired by utilizing particle swarm optimization algorithm. Simultaneously, aluminum alloy honeycomb sample is made to verify the accuracy of finite element simulation and theoretical models under quasi-static compression. Subsequently, the optimal thicknesses of three layers are optimized with the constraint that the 1st mode frequency is more than 30 Hz. Finally, the mass of the optimized battery box decreases by 37.26 %, and its static performances increase more largely compared with traditional one.

Serotype-Independent Protection against Pneumococcal Infections Elicited by Intranasal Immunization with Ethanol-Killed Pneumococcal Strain, SPY1

XiuYu Xu,Qun Zhang,Jiangping Meng,Yiping Wang,Jie Zheng,Kaifeng Wu,Xuemei Zhang,Yibing Yin 한국미생물학회 2014 The journal of microbiology Vol.52 No.4

The 23-valent polysaccharide vaccine and the 7-valent pneumococcalconjugate vaccine are licensed vaccines that protectagainst pneumococcal infections worldwide. However,the incidence of pneumococcal diseases remains high in lowincomecountries. Whole-cell vaccines with high safety andstrong immunogenicity may be a favorable choice. We previouslyobtained a capsule-deficient Streptococcus pneumoniaemutant named SPY1 derived from strain D39. As anattenuated live pneumococcal vaccine, intranasal immunizationwith SPY1 elicits broad serotype-independent protectionagainst pneumococcal infection. In this study, forsafety consideration, we inactivated SPY1 with 70% ethanoland intranasally immunized BALB/c mice with killed SPY1plus cholera toxin adjuvant for four times. Results showedthat intranasal immunization with inactivated SPY1 inducedstrong humoral and cellular immune responses. Intranasalimmunization with inactivated SPY1 plus cholera toxin adjuvantelicited effective serotype-independent protection againstthe colonization of pneumococcal strains 19F and 4 as well aslethal infection of pneumococcal serotypes 2, 3, 14, and 6B. The protection rates provided by inactivated SPY1 againstlethal pneumococcal infection were comparable to those ofcurrently used polysaccharide vaccines. In addition, vaccinespecificB-cell and T-cell immune responses mediated theprotection elicited by SPY1. In conclusion, the 70% ethanolinactivatedpneumococcal whole-cell vaccine SPY1 is a potentiallysafe and less complex vaccine strategy that offersbroad protection against S. pneumoniae.

Preparation of Non-Planar-Ring Epoxy Thermosets Combining Ultra-Strong Shape Memory Effects and High Performance

Qiong Li,Songqi Ma,Jingjing Wei,Sheng Wang,Xiwei Xu,Kaifeng Huang,Binbo Wang,Wangchao Yuan,Jin Zhu 한국고분자학회 2020 Macromolecular Research Vol.28 No.5

Non-planar-ring epoxies together with non-planar-ring hardeners could achieve thermosets combining ultra-high shape recovery speed and excellent thermal properties. High shape recovery speed reflected high efficiency, and could decrease the energy consumption and the harmful effect of external stimuli on the materials, while it often conflicts with the thermal properties of shape memory polymers. In this paper, for the first time, epoxy resins with the super-short shape recovery time within 3 s were developed from non-planar-ring epoxies and hardeners, and their glass transition temperature (T g) were ~127 °C much higher than their benzene ring analogues. The effects of non-planar-ring structures of the epoxies and hardeners on the curing behavior, thermal properties as well as the shape memory properties of the thermosets were systematically investigated; the structure-property relationships were disclosed with the help of computational simulation of structure parameters and ESP maps. The faster shape recovery speed of the non-planar-ring epoxy thermosets is from their higher molecular mobility contributed by the conformational transition of non-planar-rings as well as their higher recovery force compared with benzene ring analogs. Their higher T gs are from the steric hindrance by the larger molecular volume of the non-planar-rings than benzene ring. This work will provide an effective method to produce shape memory polymers with excellent shape memory effects and high performance.