Relationship of High Sensitivity C-Reactive Protein with Cardiovascular, Diabetic, and Hepatic Biomarkers

Biomarkers are early predictors of various disorders, circulating level of C-reactive protein is a sensitive biomarker of systemic inflammation and may also be associated with the development of diabetic, hepatic, and cardiovascular diseases. In the present study, we aimed to investigate the association between circulating levels of high sensitive C-reactive protein (hs-CRP) and various biomarkers for hepatic, diabetic, and cardiovascular health. The retrospective analysis included 438 individuals who were tested for these panels simultaneously at Vibrant America Clinical Laboratory. The study population included free-living individuals without any preexisting clinical conditions. Among the cardiovascular markers, a positive correlation and significant association was found between high levels of hs-CRP and serum levels of triglycerides (r = 0.0964, p −0.1423, p −0.1216, p < 0.0105) with circulating levels of hs-CRP. Among all the diabetic markers, glucose (r = 0.1547, p < 0.0011) and glycated serum protein (r = 0.1725, p < 0.0003) were positively correlated with circulating hs-CRP. In the hepatic panel, AST, a transaminase that plays a vital role in amino acid metabolism, was found to have a strong positive correlation with hs-CRP (r = 0.2139, p < 0.0001). In conclusion, the results clearly show the association of hs-CRP with diabetic, hepatic, and cardiovascular risk factors indicating its central value as a key marker for several lifestyle-associated disorders.

Design of the reactive dyes containing large planar multi-conjugated systems and their application in non-aqueous dyeing

The development of pollution-free dyeing technology, including anhydrous dyeing and non-aqueous dyeing technologies, has always been an important way and research hot in energy conservation and emission reduction. Designing new structural dye molecules is the key to water-saving dyeing processes.Herein, three reactive dyes were designed and synthesized, which contained large planar multiconjugated systems and multi-reactive groups. The designed reactive dyes are expected to have high affinity and high fixations in non-aqueous or small bath dyeing processes. The reactive dyes were applied in the decamethylcyclopentasiloxane(DMCS) reverse micelle dyeing for cotton fabric. High exhaustion rate of 99.35%, 98.10% and 98.80%, and fixation rate of 95.15%, 96.34% and 94.40% for three dyes, R1,R2 and R3, could be respectively obtained. The dyes can be fully utilized and had excellent dyeing performance, fastness and levelling properties under the revere micelle dyeing. The cotton fabric is like an oil-water separator in the dyeing process, where the dye micelles rapidly absorb and permeate into the cotton fibers. DMCS circulates around the fabric to transfer mass and energy. After dyeing, the solvent can be separated quickly and reused. The new reactive dyes containing large planar and multi-conjugated systems have potential application in green and sustainable dyeing technology with less wastewater and higher utilization.

Maraviroc promotes recovery from traumatic brain injury in mice by suppression of neuroinflammation and activation of neurotoxic reactive astrocytes

Neuroinflammation and the NACHT,LRR,and PYD domains-containing protein 3 inflammasome play crucial roles in secondary tissue damage following an initial insult in patients with traumatic brain injury(TBI).Maraviroc,a C-C chemokine receptor type 5 antagonist,has been viewed as a new therapeutic strategy for many neuroinflammatory diseases.We studied the effect of maraviroc on TBI-induced neuroinflammation.A moderate-TBI mouse model was subjected to a controlled cortical impact device.Maraviroc or vehicle was injected intraperitoneally 1 hour after TBI and then once per day for 3 consecutive days.Western blot,immunohistochemistry,and TUNEL(terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling)analyses were performed to evaluate the molecular mechanisms of maraviroc at 3 days post-TBI.Our results suggest that maraviroc administration reduced NACHT,LRR,and PYD domains-containing protein 3 inflammasome activation,modulated microglial polarization from M1 to M2,decreased neutrophil and macrophage infiltration,and inhibited the release of inflammatory factors after TBI.Moreover,maraviroc treatment decreased the activation of neurotoxic reactive astrocytes,which,in turn,exacerbated neuronal cell death.Additionally,we confirmed the neuroprotective effect of maraviroc using the modified neurological severity score,rotarod test,Morris water maze test,and lesion volume measurements.In summary,our findings indicate that maraviroc might be a desirable pharmacotherapeutic strategy for TBI,and C-C chemokine receptor type 5 might be a promising pharmacotherapeutic target to improve recovery after TBI.

High glucose induces myocardial cell injury through increasing reactive oxygen species production

Objective: To study the injury effect and molecular mechanism of high glucose on myocardial cells. Methods: Myocardial cells H9 c2 were cultured and divided into the control group treated with DMEM containing 5.5 mmol/L glucose, the high glucose group treated with DMEM containing 35 mmol/L glucose, and the N-acetylcysteine(NAC) group pre-treated with 1000μmol/L NAC and treated with DMEM containing 1000 μmol/L NAC and 35 mmol/L glucose.The production of ROS and the expression of mitochondria pathway apoptosis molecules in cells as well as the contents of collagen and collagen metabolism molecules were measured.Results: After 8 h, 16 h and 24 h of treatment, ROS RFU as well as Bax, CytC, Caspase-3 and Caspase-9 protein expression in cells and Col-I, Col-Ⅲ, PINP and PⅢNP protein levels in culture medium of high glucose group were higher than those of control group, Bcl-2 protein expression were lower than those of control group, but CTX-Ⅰ protein levels in culture medium were not significantly different from those of control group; after 24 h of treatment, Bax, CytC,Caspase-3 and Caspase-9 protein expression in cells as well as Col-Ⅰ, Col-Ⅲ, PINP and PIIINP protein levels in culture medium of NAC group were lower than those of high glucose group whereas Bcl-2 protein expression was higher than that of high glucose group. Conclusions:High glucose can induce myocardial cell apoptosis, increase collagen synthesis and accelerate interstitial fibrosis by increasing the production of reactive oxygen species.

Novel Method for Preparation of Polypropylene Blends with High Melt Strength by Reactive Compounding

Ultrafine full-vulcanized polybutadiene rubber（UFBR） with particle sizes of ca.50―100 nm were used for modifying mechanical and processing performances of polypropylene（PP） with PP-g-maleic anhydride（PP-g-MA） as a compatibilizer for enhancing the interfacial adhesion between the two components.The morphology,dynamical rheology response and mechanical properties of the blends were characterized by means of SEM,rheometer and tensile test,respectively.The results show that the ternary PP/UFBR blends compatibilized with PP-g-MA possess rheological behaviors like highly branched PP,while no obvious strain hardening is observed in its control binary PP/UFBR blends,a low level of PP-g-MA in PP/UFBR blends can even endow the material with rheological characteristics of high melt strength materials like highly branched PP.The enhancement interfacial interaction between the UFBR particles and PP matrix accounting for the rheological behavior of compatibilized blends and effectiveness of PP-g-MA were proposed and proved.

Correlation of Enhancement Degree on Contrast-enhanced Ultrasound with Histopathology of Carotid Plaques and Serum High Sensitive C-Reactive Protein Levels in Patients Undergoing Carotid Endarterectomy

This study was undertaken to investigate the correlation of the enhancement degree on contrast-enhanced ultrasound(CEUS) with the histopathology of carotid plaques and the serum high sensitive C-reactive protein(hs-CRP) levels in patients undergoing carotid endarterectomy(CEA). Carotid CEUS was performed preoperatively in 115 patients who would undergo CEA, and the enhancement degree of the carotid plaques was evaluated by both the visual semiquantitative analysis and the quantitative time-intensity curve analysis. Serum hs-CRP levels were detected using the particle-enhanced immunoturbidimetric assay also before the operation. Additionally, the carotid plaque samples were subjected to histopathological examination postoperatively. The density of neovessels and the number of macrophages in the plaques were assessed by immunohistochemistry. The results showed that among the 115 patients, grade 0 plaque contrast enhancement was noted in 35 patients, grade 1 in 48 patients and grade 2 in 32 patients. The degree of plaque enhancement, the density of neovessels, the number of macrophages, and the hs-CRP levels were highest in the grade 2 patients. Correlation analysis showed that the enhancement degree of the carotid plaques was closely related to the immunohistochemical parameters of the plaques and the serum hs-CRP levels. It was suggested that the carotid plaque enhancement on CEUS can be used to evaluate the vulnerability of carotid plaques.

Idiopathic Reactive Hypoglycemia: Mechanisms of Onset and Remission with High Protein Low Carbohydrate Diet

Objective: Idiopathic reactive hypoglycemia is defined as early postprandial hypoglycemia occurring on ingestion of high carbohydrate containing meal. Remission ensues with high protein low carbohydrate diet. This study assessed roles of insulin and glucagon in its onset and remission. Methods: Plasma glucose, insulin and glucagon were determined after an overnight fast and repeatedly until 180 minutes on ingestion of 3 meals;100 g glucose;100 g pure protein liquid and mixture of 50 g each at 14 days’ interval. Five adults with IRH and 6 age matched healthy volunteers participated. Results: In IRH, glucose ingestion induced prompt rise in glucose (5.1 ± 0.8 to10.5 ± 1.2 mM/L) followed later by hypoglycemia (2.6 ± 0.4 mM/L). Insulin rose from 7 ± 2 to 90 ± 18 mU/L. Glucagon rose initially (10% ± 2%) from elevated basal concentration (373 ± 57 mU/L) followed by later decline (-43% ± 12%). On protein ingestion, glucose declined followed by a restoration to basal level while both insulin and glucagon rose (28 ± 6 mU/L;148% ± 38%, p < 0.01). However, insulin response was lower and glucagon rise was greater when compared to responses on glucose ingestion (p < 0.01). With mixed meal, glucose (8.2 ± 0.6 mM/L), insulin (65 ± 12 mU/L) and glucagon (48% ± 7%) responses were lesser than rises following glucose ingestion (p < 0.05) and hypoglycemia did not occur. Conclusion: In IRH, initial hyperglycemia on glucose ingestion may be exacerbated by paradoxical glucagon rise and hypoglycemia may be induced by increased insulin and declining glucagon responses. Resolution of hypoglycemia with high protein low carbohydrate diet may be attributed to blunting of insulin response and concurrent glucagon rise.

Myeloperoxidase and High-Sensitivity C-Reactive Protein for Predicting Major Adverse Cardiovascular Events in Patients with Coronary Heart Disease

Background: Research has shown that high-sensitivity C-reactive protein (hs-CRP) is a major inflammatory marker for prediction of acute coronary syndrome (ACS). Myeloperoxidase (MPO) also plays an important role in atherosclerosis initiation and development. In present study, the major adverse cardiovascular events (MACEs) of patients with coronary heart disease (CHD) were investigated. Methods: MPO, hs-CRP and ACS-related risk factors from 201 ACS (78 AMI and 123 UAP) and 210 non-ACS (84 SAP and 126 non-CHD) patients confirmed by coronary angiography were detected, and the data were analyzed with receiver operating characteristic (ROC) curve and Spearman’s correlation coefficients. MACEs of 285 CHD patients were investigated during the 4-year period follow-up from March 2010 to May 2014. Results: The areas under ROC curve for diagnosing ACS were 0.888 (95% CI 0.843 - 0.933) for MPO, and 0.862 (95% CI 0.815-0.910) for hs-CRP, respectively. There were significantly correlations between MPO and hs-CRP in both ACS and non-ACS groups. Regarding to ACS patients, both MPO and hs-CRP were positively correlated with BMI, TC, TG, LDL-C and Hcy. Prospective study demonstrated that the incidences of MACEs associated significantly with elevated MPO baseline level (yes vs no, OR 7.383, 95% CI 4.095 - 13.309) and high hs-CRP baseline level (yes vs no, OR 4.186, 95% CI 2.469 - 7.097) in CHD patients. Conclusions: The present study provides the epidemiological evidence that elevated baseline MPO and hs-CRP levels are both valuable predictors of MACEs in CHD patients. MPO and hs-CRP would prompt the progression of atherosclerosis and development from SAP to ACS.

Trap states induced by reactive ion etching in AlGaN/GaN high-electron-mobility transistors

Frequency-dependent conductance measurements were carried out to investigate the trap states induced by reactive ion etching in A1GaN/GaN high-electron-mobility transistors （HEMTs） quantitatively. For the non-recessed HEMT, the trap state density decreases from 2.48 × 1013 cm-2.eV-1 at an energy of 0.29 eV to 2.79 × 1012 cm-2.eV-1 at ET = 0.33 eV. In contrast, the trap state density of 2.38 × 1013-1.10× 1014 cm-2.eV-1 is located at ET in a range of 0.30-0.33 eV for the recessed HEMT. Thus, lots of trap states with shallow energy levels are induced by the gate recess etching. The induced shallow trap states can be changed into deep trap states by 350 ℃ annealing process. As a result, there are two different types of trap sates, fast and slow, in the annealed HEMT. The parameters of the annealed HEMT are ET = 0.29-0.31 eV and DT = 8.16× 1012-5.58 × 1013 cm-2.eV-1 for the fast trap states, and ET = 0.37-0.45 eV and DT = 1.84×1013- 8.50 × 1013 cm-2.eV-1 for the slow trap states. The gate leakage currents are changed by the etching and following annealing process, and this change can be explained by the analysis of the trap states.

Responses of serum inflammatory factor high-sensitivity C-reactive protein, interleukin-6, and tumor necrosis factor-alpha in elderly males with cerebral infarction Non-randomized concurrent control

BACKGROUND： Cerebral infarction is poorly treated due to neuronal necrosis and secondary pathophysiological changes; for example, free radical production and inflammatory reactions. OBJECTIVE： To detect the levels of high-sensitivity C-reactive protein （hs-CRP）, interleukin-6 （IL-6）, and tumor necrosis factor- a （TNF- α ） in elderly males with cerebral infarction. DESIGN： Non-randomized current control study. SETTING： Cadre Medical Department, Guizhou Provincial People＇s Hospital. PARTICIPANTS： Forty elderly males （65-89 years old） with cerebral infarction were selected from Cadre Medical Department, Guizhou Provincial People＇s Hospital from February 2004 to December 2006. All patients met the diagnostic criteria of cerebral infarction modified at the 4th National Cerebrovascular Disease Academic Meeting, and were diagnosed on the basis of CT or MRI tests. Furthermore, 35 elderly male inpatients （65-87 years old） without cerebral infarction were selected as the control group. Included subjects provided confirmed consent and did not have heart disease, diabetes mellitus, lipid disorder, acute trauma, infection, rheumatism, or other inflammatory diseases. The study was approved by the local ethics committee. There were no significant differences in age, blood pressure, and lipid levels between the cerebral infarction group and the control group （P 〉 0.05）, and this suggested that the baseline data of both groups were comparable. METHODS： Fasting venous blood was drawn from cerebral infarction patients 24 hours after cerebral infarction attack and from control subjects 24 hours after hospitalization. A latex-enhanced immunoturbidimetric assay and an enzyme-linked immunosorbent assay were used to detect the levels of hs-CRP, IL-6, and TNF- α in the serum. MAIN OUTCOME MEASURES： The levels of hs-CRP, 1L-6, and TNF- α in the serum in both groups. RESULTS： Forty cerebral infarction patients and thirty-five control subjects were included in the final analysis without any loss. Levels of hs-CRP, IL-6, and TNF-α in the cerebral infarction group were significantly higher than those in the control group （P 〈 0.01 ）. CONCLUSION： Levels of serum inflammatory reactive factors are increased in elderly males with cerebral infarction.

Study of the Corrosion of High Alumina Refractories by Al_2O_3-CaO Slag as a Reactive Impregnation Mechanism

The corrosion of refractories results from reactive transport,namely,transport of agents and chemical reactions of these agents with impregnated medium. On one hand,the transport involves either diffusion or impregnation depending on the state of the corrosive agents and the microstructure of the host media. On the other hand,chemical reactions may be very numerous and complex.This study focused on the reactive impregnation of Al2O3- CaO slag into porous high alumina refractory. The transport properties of the refractory material were identified by means of a dedicated capillary rising test. Chemical reactions between the solid high alumina skeleton and Al2O3- CaO slag involve successive dissolution / precipitation mechanisms forming aluminates of lime. Contrary to the thermodynamic properties of the binary system,the kinetics of these solid / liquid reactions is not well known.Corrosion tests associated with the quenching method,XRD analyses were performed for a better understanding of the kinetics. The results of this study open up a coupling approach for predicting the corrosion wear of refractory.

Manufacturing a TiAl alloy by high-energy ball milling and subsequent reactive sintering

A TiAl alloy was fabricated by high-energy ball milling and subsequent reactive sintering from the mixed powders of Ti and Al. High-energy ball milling produced a kind of particular composite powders with an extremely fine altemative Ti and Al lamella structure. The composite powders not only possessed good consolidation and densification characteristics, but also resulted in the augment of nucleation rate of α and γ titanium aluminides during solid-phase reactive sintering After a series of processing, pressing, degassing, extrusion, and sintering, the resultant TiAl alloy presented high relative density and refined grain sizes of （α2 ＋ γ） lamella and γ phases. The compressive yield strength of the sintered TiAl reached 600 MPa at 800℃.

Clinical application of neutrophil/lymphocyte ratio combined with high sensitive C reactive protein in evaluation of community acquired pneumonia

Objective:To explore the application value of neutrophil/lymphocyte ratio (NLR) combined with high sensitive C reactive protein (hs-CRP) in the evaluation of community acquired pneumonia (CAP). Methods:From November 2015 to October 2016, 58 cases of CAP patients admitted in our department were selected as research objects and were divided into low risk group and high risk group according to the PSI score and CURB-65 standard for evaluation. They were divided into improved group (48 cases) and death group (10 cases) according to prognosis. Hs-CRP was determined by immunoturbidimetric assay, procalcitonin (PCT) by immunofluorescence, NLR by count method of laser scattering, and white blood (WBC) was counted. The differences in WBC, PCT, NLR and hs-CRP between different risk groups were compared, and the correlation was evaluated using Spearman's rank correlation analysis method. The changes in indexes were observed in the improved and death cases. Results:The high risk group had higher NLR, PCT and hs-CRP than low risk group (P<0.05), while no significant difference was found in WBC (P>0.05). No correlation was found between NLR and WBC, while a strong correlation was found between hs-CRP and PCT. The WBC, PCT, NLR and hs-CRP levels were significantly lower in the improved group than the death group (P<0.05). Conclusions:NLR combined with hs-CRP, WBC, and PCT has a good assessment of the severity of CAR, and high levels of NLR, hs-CRP, WBC, and PCT predict the severity of the disease and poor prognosis.

High Sensitivity C-Reactive Protein Associated with Different Health Predictors in Middle-Aged and oldest old Chinese

Objective To describe the distribution of plasma high sensitivity C-reactive protein （hsCRP） and explore the relationship between hsCRP and metabolic risk factors among residents living in longevity areas of China. Methods 268 individuals aged between 40 and 59 years and 506 individuals aged over 90 years were selected from 5 longevity areas of China to participate in a cross section longitudinal cohort study. The participants were interviewed with general health related questionnaire to collect their demographic, behavioral and lifestyle data, as well as their chronic conditions, and meanwhile their physical and biomedical parameters including waist circumference （WC）, blood pressure （BP）, hsCRP, plasma lipids, and fasting blood glucose （FBG） were measured. Results The median of hsCRP was 0.99 mg/L in the middle-aged group and 2.76 mg/L in the oldest old group. No significant gender difference was observed between the above two groups. Among the oldest old individuals, 36.56% had an hsCRP level 〉3.0 mg/L. The prevalence of high hsCRP was 26.79% in the middle-aged group. The results of stepwise multiple linear regression analyses showed that HDL-C was independently associated with In （hsCRP） concentration in the middle-aged group, whereas In （TG）, HDL-C and FBG were correlated after adjustment for gender, study site, smoking, drinking, education and BMI in the oldest old group. Conclusion HDL-C is a stronger predictor of elevated hsCRP than other metabolic factors in the middle-aged population. For the oldest old persons, high TG, low HDL-C, and FBG predict elevated plasma hsCRP.

Statistical model for combustion of high-metal magnesium-based hydro-reactive fuel

We investigate experimentally and analytically the combustion behavior of a high-metal magnesium-based hydro- reactive fuel under high temperature gaseous atmosphere. The fuel studied in this paper contains 73% magnesium powders. An experimental system is designed and experiments are carried out in both argon and water vapor atmo- spheres. It is found that the burning surface temperature of the fuel is higher in water vapor than that in argon and both of them are higher than the melting point of magnesium, which indicates the molten state of magnesium particles in the burning surface of the fuel. Based on physical considerations and experimental results, a mathematical one-dimensional model is formulated to describe the combustion behavior of the high-metal magnesium-based hydro-reactive fuel. The model enables the evaluation of the burning surface temperature, the burning rate and the flame standoff distance each as a function of chamber pressure and water vapor concentration. The results predicted by the model show that the burning rate and the surface temperature increase when the chamber pressure and the water vapor concentration increase, which are in agreement with the observed experimental trends.

Current status of high on-treatment platelet reactivity in patients with coronary or peripheral arterial disease:Mechanisms,evaluation and clinical implications

Antiplatelet therapy with aspirin or clopidogrel or both is the standard care for patients with proven coronary or peripheral arterial disease,especially those undergoing endovascular revascularization procedures. However,despite the administration of the antiplatelet regiments,some patients still experience recurrent cardiovascular ischemic events. So far,it is well documented by several studies that in vitro response of platelets may be extremely variable. Poor antiplatelet effect of clopidogrel or high on-treatment platelet reactivity(HTPR) is under investigation by numerous recent studies. This review article focuses on methods used for the ex vivo evaluation of HTPR,as well as on the possible underlying mechanisms and the clinical consequences of this entity. Alternative therapeutic options and future directions are also addressed.

Durability and Micro-structure of Reactive Powder Concrete

Durability of traditional reactive powder concrete （RPC） with rich cement and high volume of fly-ash reactive powder concrete （FRPC） were studied. The X-diffraction and scanning electron microscope （SEM） measurement was imployed to analyze the microstructure. The results show that both types of RPC have higher compressive strength, less volume shrinkage ratio and better carbonation-, chloride-, freezing-resistances than the conventional concrete. The results of X-diffraction indicate that they basically have C-S-H as the main composition without Ca（OH）2 crystal and ettringite. SEM results show that hydration products of FRPC is mainly Ⅲ-C-S-H which is piled up closely like densely arranged stone body and it has very compacted structure, in addition, Ca/Si ratio of C-S-H gel is lower than 1.5.

Optimal Reactive Power Compensation of Distribution Network to Prevent Reactive Power Reverse

The capacitive reactive power reversal in the urban distribution grid is increasingly prominent at the period of light load in the last years.In severe cases,it will endanger the security and stability of power grid.This paper presents an optimal reactive power compensation method of distribution network to prevent reactive power reverse.Firstly,an integrated reactive power planning(RPP)model with power factor constraints is established.Capacitors and reactors are considered to be installed in the distribution system at the same time.The objective function is the cost minimization of compensation and real power loss with transformers and lines during the planning period.Nodal power factor limits and reactor capacity constraints are new constraints.Then,power factor sensitivity with respect to reactive power is derived.An improved genetic algorithm by power factor sensitivity is used to solve the model.The optimal locations and sizes of reactors and capacitors can avoid reactive power reversal and power factor exceeding the limit.Finally,the effectiveness of the model and algorithm is proven by a typical high-voltage distribution network.

The Effect of Various Polynaphthalene Sulfonate Based Superplasticizers on the Workability of Reactive Powder Concrete

A superplasticizer is a type of chemical admixture used to alter the workability(viscosity)of fresh concrete.The workability of fresh concrete is often of particular importance when the water-to-cement(w/c)ratio is low and a particular workability is desired.Reactive Powder Concrete(RPC)is a high-strength concrete formulated to provide compressive strengths exceeding 130MPa and made of primarily powders.RPC materials typically have a very low w/c,which requires the use of a chemical admixture in order to create a material that is easier to place,handle and consolidate.Superplasticizer are commonly used for this purpose.Superplasticizers are developed from different formulations,the most common being Polycarboxylate Ether(PCE),Polymelamine Sulfonate(PMS),and Polynaphthalene Sulfonate(PNS).This study investigates the effect of various PNS based superplasticizers on the rheological performance and mechanical(compressive strength)performance of a RPC mixture.Six distinctive types of PNS based superplasticizers were used;three of various compositional strengths(high,medium,low range)from a local provider,and three of the same compositional strengths(high,medium,low)from a leading manufacturer.The properties investigated were the individual superplasticizers’viscosity,the concrete workability,determined through a mortar spread test,the concrete viscosity,and the compressive strength of the hardened RPC mixtures measured at 7,14,and 28 days.Two separate RPC mixtures were prepared,which contained two different water-to-cementitious ratios,which consequently increases the dosage of superplasticizer needed,from 34.8L/m3 to 44.7L/m3.The results show that the name brand high range composition produced the overall highest spread,lowest viscosity,and a highest compressive performance.However,the local provider outperformed the name brand in the mid and low range compositions.Lastly,the rheology assessment also confirmed that the name brand high range,and RPC fabricated with the name brand high range,developed the lowest viscosities.

高空电磁脉冲晚期成分作用下500 kV变压器无功损耗仿真研究

高空电磁脉冲晚期成分(HEMP E3)效应会在变压器中性点与大地构成的回路中产生地磁感应电流(GIC),严重时会使变压器铁心半波饱和,进而导致励磁电流严重畸变、无功损耗急剧增加、局部过热和振动加剧等后果。为准确地分析电力变压器在HEMPE3作用下的无功损耗特性,该文搭建了HEMP E3对500 kV电力变压器作用的电磁暂态仿真模型,基于IEC 61000-2-9给出的标准HEMP E3波形,定量分析了感应电场幅值、上升时间、下降时间以及变压器带负载情况等对电力变压器的影响规律。分析结果表明,HEMP E3作用下500 kV变压器无功损耗与GIC呈正相关性,且无功损耗波形滞后于感应电场的变化;HEMP E3感应电场的下降时间对500 kV变压器无功损耗的影响远超上升时间;负载阻抗的阻值相同时,容性负载下的励磁电流和无功损耗幅值最大,感性负载下幅值最小。研究结果可为进一步评估HEMPE3对电力系统稳定性的影响提供重要依据。