Phase angle obtained by bioelectrical impedance analysis independently predicts mortality in patients with cirrhosis

AIM To evaluate the prognostic value of the phase angle(PA)obtained from bioelectrical impedance analysis(BIA) for mortality prediction in patients with cirrhosis. METHODS In total, 134 male cirrhotic patients prospectively completed clinical evaluations and nutritional assessment by BIA to obtain PAs during a 36-mo follow-up period. Mortality risk was analyzed by applying the PA cutoff point recently proposed as a malnutrition marker(PA ≤ 4.9°) in Kaplan-Meier curves and multivariate Cox regression models. RESULTS The patients were divided into two groups according to the PA cutoff value(PA > 4.9°, n = 73; PA ≤ 4.9°, n = 61). Weight, height, and body mass index were similar in both groups, but patients with PAs > 4.9° were younger and had higher mid-arm muscle circumference, albumin, and handgrip-strength values and lower severe ascites and encephalopathy incidences, interleukin(IL)-6/IL-10 ratios and C-reactive protein levels than did patients with PAs ≤ 4.9°(P ≤ 0.05). Forty-eight(35.80%) patients died due to cirrhosis, with a median of 18 mo(interquartile range, 3.3-25.6 mo) follow-up until death. Thirty-one(64.60%) of these patients were from the PA ≤ 4.9° group. PA ≤ 4.9° significantly and independently affected the mortality model adjusted for Model for End-Stage Liver Disease score and age(hazard ratio = 2.05, 95%CI: 1.11-3.77, P = 0.021). In addition, Kaplan-Meier curves showed that patients with PAs ≤ 4.9° were significantly more likely to die. CONCLUSION In male patients with cirrhosis, the PA ≤ 4.9° cutoff was associated independently with mortality and identified patients with worse metabolic, nutritional, and disease progression profiles. The PA may be a useful and reliable bedside tool to evaluate prognosis in cirrhosis.

Bioelectrical impedance analysis-guided fluid management promotes primary fascial closure after open abdomen:a randomized controlled trial

Background:Fluid overload(FO)after resuscitation is frequent and contributes to adverse outcomes among postinjury open abdomen(OA)patients.Bioelectrical impedance analysis(BIA)is a promising tool for monitoring fluid status and FO.Therefore,we sought to investigate the efficacy of BIA-directed fluid resuscitation among OA patients.Methods:A pragmatic,prospective,randomized,observer-blind,single-center trial was performed for all trauma patients requiring OA between January 2013 and December 2017 to a national referral center.A total of 140 postinjury OA patients were randomly assigned in a 1:1 ratio to receive either a BIA-directed fluid resuscitation(defined as BIA)protocol that included fluid administration with monitoring of hemodynamic parameters and different degrees of interventions to achieve a negative fluid balance targeting the hydration level(HL)measured by BIA or a traditional fluid resuscitation(TRD)in which clinicians determined the fluid resuscitation regimen according to traditional parameters during 30 d of intensive care unit(ICU)management.The primary outcome was the 30-day primary fascial closure(PFC)rate.The secondary outcomes included the time to PFC,postoperative 7-day cumulative fluid balance(CFB)and adverse events within 30 d after OA.The Kaplan–Meier method and the log-rank test were utilized for PFC after OA.A generalized linear regression model for the time to PFC and CFB was built.Results:A total of 134 patients completed the trial(BIA,n=66;TRD,n=68).The BIA patients were significantly more likely to achieve PFC than the TRD patients(83.33%vs.55.88%,P<0.001).In the BIA group,the time to PFC occurred earlier than that of the TRD group by an average of 3.66 d(P<0.001).Additionally,the BIA group showed a lower postoperative 7-day CFB by an average of 6632.80 ml(P<0.001)and fewer complications.Conclusions:Among postinjury OA patients in the ICU,the use of BIA-guided fluid resuscitation resulted in a higher PFC rate and fewer severe complications than the traditional fluid resuscitation strategy.

AN IMPEDANCE ANALYSIS FOR CRACK DETECTION IN THE TIMOSHENKO BEAM BASED ON THE ANTI-RESONANCE TECHNIQUE

An alternative technique for crack detection in a Timoshenko beam based on the first anti-resonant frequency is presented in this paper. Unlike the natural frequency, the anti-resonant frequency is a local parameter rather than a global parameter of structures, thus the proposed technique can be used to locate the structural defects. An impedance analysis of a cracked beam stimulated by a harmonic force based on the Timoshenko beam formulation is investigated. In order to characterize the local discontinuity due to cracks, a rotational spring model based on fracture mechanics is proposed to model the crack. Subsequently, the proposed method is verified by a numerical example of a simply-supported beam with a crack. The effect of the crack size on the anti-resonant frequency is investigated. The position of the crack of the simply-supported beam is also determined by the anti-resonance technique. The proposed technique is further applied to the ＂contaminated＂ anti-resonant frequency to detect crack damage, which is obtained by adding 1-3% noise to the calculated data. It is found that the proposed technique is effective and free from the environment noise. Finally, an experimental study is performed, which further verifies the validity of the proposed crack identification technique.

Simultaneous Impedance Analysis of Three Parallel Piezoelectric Quartz Crystals for Electrochemical Depletion Layer Effect Study

Simultaneous impedance analysis of three one-face sealed resonating piezoelectric quartz crystals (PQCs) in parallel is proposed through admittance measurements of the three PQCs on one impedance analyzer and then non-linear fitting according to the parallel combination of three Butterworth-Van Dyke circuits. Responses of each PQC obtained from the three-PQC mode agreed well with those measured separately in series sucrose aqueous solutions. This novel method has been used for the study of depletion-layer effect during ferri-/ferrocyanide electrochemical reactions.

Characterizing temperature dependent complex electrical impedance analysis of LaFe_(1−x)Zn_(x)O_(3)(x=0.03,0.05,and 0.07)ceramics

followed by sintering-annealing treatments to form the bulk-phase.X-ray diffraction analysis revealed that all ceramics were crystallized in the orthorhombic perovskite structure with Pbnm symmetry.Grain size distribution and morphological characteri-stics were investigated by scanning electron microscopy.Specific surface area was analyzed through BET-BJH methods.Electrical impedance analysis was investigated as a function of frequency at various temperatures.It was found that the electrical behavior is dominated by grain boundary contribution,i.e.,electrical conductivity.The frequency dependence of the complex conductivity was analyzed through Joncher’s power law and the dominance of translational motion with a sudden hopping mechanism in the electrical conduction mechanism increased with increasing Zn content.Activation energy decreased with increasing Zn content.

Bioelectrical impedance vector analysis evaluates cellularity and hydration in cirrhotic patients

BACKGROUND Malnutrition in cirrhotic patients is correlated with mortality and a better response to liver transplantation.However,recovery of the nutritional status in these patients is a challenge due to the difficulty in establishing a reliable nutritional diagnosis.The bioelectrical impedance vector analysis(BIVA)method appears as a feasible tool in clinical practice to define the physiological state of cirrhotic patients by assessing hydration and body cellularity.AIM To evaluate body composition in cirrhotic patients using BIVA.METHODS This retrospective cross-sectional study was carried out by following cirrhotic outpatients at a hospital in Porto Alegre,Brazil.A tetrapolar bioelectrical impedance analysis device was used to evaluate cellularity and hydration and to perform the BIVA.The BIVA graphic was elaborated by software and for statistical analysis a significance level of 5%(P≤0.05)was considered.RESULTS One hundred and ninety patients,61.1%males,with a mean age of 56.6±11.0 years,were evaluated.Of these,56.3%had Child-Turcotte-Pugh(CTP)A score,and the prevalent etiology was hepatitis C virus(47.4%).The patients were classified according to cellularity and hydration by the quadrants and ellipses of the BIVA method,quadrant 1(47.9%);quadrant 2(18.9%);quadrant 3(14.2%);and quadrant 4(18.9%).Those classified in quadrant 1 and 2 had a higher phase angle compared to those in quadrants 3 and 4(P<0.001).Quadrant 2 patients had a lower average age than the other groups.The association with CTP score showed that patients in quadrant 2 had a higher proportion of CTP A,and those in quadrant 4 had a higher proportion of CTP C(P<0.052).CONCLUSION The BIVA method allows identification of the cellularity and hydration status of cirrhotic patients,and its association with clinical factors determines the disease severity,age and prognostic index.

Evaluation of Dielectric Properties of CCTO-BT/Epoxy Composites for Electronic Applications

In the current study,the calcium copper titanate(CCTO)/epoxy,barium titanate(BT)/epoxy and CCTO-BT/epoxy composite samples with variable volume fractions of CCTO and BT are fabricated using hand lay-up and compression moulding process. The composite samples are characterized for the frequency dependence on dielectric properties,conductivity,impedance spectroscopy and electrical modulus.X-ray diffraction(XRD)representation of CCTO-BT/epoxy composite samples confirmed the presence of both CCTO and BT ceramic samples separately. The dielectric characteristics of hybrid CCTO-BT/epoxy composite samples with CCTO∶BT ratio of 40∶60, 60∶40,and 50∶50 was found relatively better than those of single ceramic filler reinforced epoxy composites. AC conductivity analysis shows improvement in the results of hybrid filler-filled CCTO-BT/epoxy composites in comparison with single filler-filled epoxy composite.50∶50 CCTO-BT/epoxy composite shows the best AC conductivity value of~ 2.2 ×10^(-5) ohm^(-1)·m^(-1) at a higher frequency of 1MHz. The impedance analysis confirms the higher insulating properties for hybrid 40∶60 and 60∶40 CCTO-BT/epoxy composites with respect to the single and other hybrid ceramic epoxy composites. The analysis suggests the hybrid CCTO-BT/epoxy composites to be adopted as a potential dielectric material for energy storage devices and other electronic applications.

Prevalence and outcome of sarcopenia in non-alcoholic fatty liver disease

BACKGROUND Nonalcoholic fatty liver disease(NAFLD)includes a spectrum of conditions,progressing from mild steatosis to advanced fibrosis.Sarcopenia,characterized by decreased muscle strength and mass,shares common pathophysiological traits with NAFLD.An association exists between sarcopenia and increased NAFLD prevalence.However,data on the prevalence of sarcopenia in NAFLD and its impact on the outcomes of NAFLD remain inconsistent.AIM To analyze the prevalence and outcomes of sarcopenia in patients with NAFLD.METHODS We conducted a comprehensive search for relevant studies in MEDLINE,Embase,and Scopus from their inception to June 2023.We included studies that focused on patients with NAFLD,reported the prevalence of sarcopenia as the primary outcome,and examined secondary outcomes,such as liver fibrosis and other adverse events.We also used the Newcastle-Ottawa scale for quality assessment.RESULTS Of the 29 studies included,the prevalence of sarcopenia in NAFLD varied widely(1.6%to 63.0%),with 20 studies reporting a prevalence of more than 10.0%.Substantial heterogeneity was noted in the measurement modalities for sarcopenia.Sarcopenia was associated with a higher risk of advanced fibrosis(odd ratio:1.97,95%confidence interval:1.44-2.70).Increased odds were consistently observed in fibrosis assessment through biopsy,NAFLD fibrosis score/body mass index,aspartate aminotransferase to alanine aminotransferase ratio,diabetes(BARD)score,and transient elastography,whereas the fibrosis-4 score showed no such association.Sarcopenia in NAFLD was associated with a higher risk of steatohepatitis,insulin resistance,cardiovascular risks,and mortality.CONCLUSION This systematic review highlights the critical need for standardized diagnostic criteria and measurement methods for sarcopenia in NAFLD patients.The variability in study designs and assessment methods for sarcopenia and liver fibrosis may account for the inconsistent findings.This review demonstrates the multidimensional impact of sarcopenia on NAFLD,indicating its importance beyond liver-related events to include cardiovascular risks,mortality,and metabolic complications.

Bioelectrical Impedance Phase Angle as a Predictors of Mortality in Patients with Lung Cancer:a Prospective Study

Objective Bioelectrical impedance analysis(BIA)is used to measure a patient's body composition.The phase angle(PA),the major parameter in BIA,is one of the most sensitive indicators of malnutrition.The aim of the current study was to investigate whether the PA can be used to predict survival in lung cancer patients.Methods One hundred sixty-six lung cancer patients were prospectively included from January 2014 to August 2016 in Daping Hospital.Anthropometric measurements,hematological values,the nutritional risk screening(NRS 2002)score,patient generated-subjective global assessment(PG-SGA)score,Karnofsky performance status(KPS)scale,European Organization for Research and Treatment of Cancer Core Quality of Life Questionnaire(EORTC QLQ C-30)score,and BIA were investigated within 48 hours after admission to the hospital.A Spearman correlation analysis was applied to test the correlations between the study characteristics and PA.A Kaplan-Meier analysis and log-rank test were conducted to analyze the association between the overall survival(OS)and PA.Results The mean age for all patients was 63 years old(42 females and 124 males).The median PA was 5.5°(4.70°,6.23°).The PA was positively associated with the body mass index,hand grip strength,mid-arm circumference,mid-arm muscle circumference,albumin,prealbumin,C-reactive protein,red blood cells,hemoglobin and KPS score.The PG-SGA scores,QLQ-C30 score,and NRS2002 score showed a significant negative association with the PA.According to a multivariate analysis,the PA(HR=0.47;95%CI:0.27-0.81)was independent predictor of the lung cancer patients'long-term OS.Patients with a higher PA(≥5°)had better overall survival(median=426 days)compared to those with a lower PA(<5°)(median=96 days)based on the one-year follow-up data(P<0.0001).Conclusions These studies indicate that the PA is a sensitive and early indicator to predict survival in lung cancer patients.

Body Composition Estimatives by Anthropometry, Bioelectrical Impedance and Deuterium Oxide Dilution in Obese Adolescents

To evaluate the relationship between measures of body composition in obese adolescents by the methods of bioelectrical impedance analysis, deuterium oxide dilution and anthropometric measures, proposing an equation. The variables were weight, height, BMI, triceps and subscapular skinfold thickness, waist and arm muscle circumference, lean body mass, fat mass and total body water by bioelectrical impedance and deuterium oxide dilution methods. The study included 40 obese adolescents, 45% male, age distribution was 2.42 ± 1.19 years and females 55%, and the predominant age was 12.61 ± 1.78. Linear regression equations were developed, capable of predicting body composition from information supplied by the method of deuterium oxide dilution (gold standard), bioelectrical impedance and anthropometry. The variables gender, age, height, arm circumference, triceps and suprailiac skin fold thickness, resistance and reactance were used to estimate lean body mass, fat mass and total body water by the method of deuterium and significantly correlated with variables, resistance, reactance, sex and total body water (TBW) by bioimpedance method. Among the equations developed, five were suitable for this sample, therefore, it is suggested that more studies should be done to test the applicability of the equations in other samples so that we can validate the equations encountered in obese adolescents.

Association of Breastfeeding Duration with Body Composition in Children Aged 3–5 Years

Objective This study aimed to assess the relationship between the body composition of children aged 3–5 years and breastfeeding status and duration.Methods The study was conducted using data from the National Nutrition and Health Systematic Survey for children 0–17 years of age in China(CNHSC),a nationwide cross-sectional study.Breastfeeding information and potential confounders were collected using standardized questionnaires administered through face-to-face interviews.The body composition of preschool children was measured using bioelectrical impedance analysis.A multivariate linear regression model was used to assess the relationship between breastfeeding duration and body composition after adjusting for potential confounders.Results In total,2,008 participants were included in the study.Of these,89.2%were ever breastfed and the median duration of breastfeeding was 12 months(IQR 7–15 months).Among children aged 3 years,the height-for-age Z-score(HAZ)for the ever breastfed group was lower than that for never breastfed group(0.12 vs.0.42,P=0.043).In addition,the weight-for-age Z-score(WAZ)of the ever breastfed group was lower than that of the never breastfed group(0.31 vs.0.65,P=0.026),and the WAZ was lower in children aged 4 years who breastfed between 12 and 23 months than in those who never breastfed.Compared to the formula-fed children,the fat-free mass of breastfed infants was higher for children aged 3 years(12.84 kg vs.12.52 kg,P=0.015)and lower for those aged 4 years(14.31 kg vs.14.64 kg,P=0.048),but no difference was detected for children aged 5 years(16.40 kg vs.16.42 kg,P=0.910)after adjusting for potential confounders.No significant difference was detected in the weight-for-height Z-score(WHZ),body mass index(BMI)-for-age Z-score(BAZ),fat-free mass index,and body fat indicators in the ever breastfed and never breastfed groups and among various breastfeeding duration groups for children aged 3–5 years.Conclusion No obvious associations were detected between breastfeeding duration,BMI,and fat mass indicators.Future prospective studies should explore the relationship between breastfeeding status and fat-free mass.

High sensitive piezoelectric quartz crystal liquid density sensor

We report for the first time a cleavage phenomenon in the resonant peak of a piezoelectric quartz crystal(PQC) in liquid phase.In the presence of a strong longitudinal wave effect,an additional resonant peak appears in the conductance-frequency curve.With gradually increasing liquid density,the additional peak moves from low to high frequency region then disappears.The frequency of the additional resonant peak is sensitive to the change in liquid density.The frequency shift of the additional peak is linear with the liquid density in a given range.For a 5 MHz PQC with a reflection distance of 16 mm for longitudinal wave,the sensitivity to liquid density is 2.61×10^6 Hz g^-1 cm^3.The overlap between the primary resonant peak and the additional resonant peak causes a decrease in the intensity of the former and an increase in the intensity of the latter.In a combined impedance analysis method,the changes in surface mass loading,density and viscosity of the liquid were monitored simultaneously by a PQC sensor.

Combining the Patient-Generated Subjective Global Assessment (PGSGA) and Objective Nutrition Assessment Parameters Better Predicts Malnutrition in Elderly Patients with Colorectal Cancer

Background Malnutrition is common in colorectal cancer(CRC)patients,especially in elderly patients.The Patient-Generated Subjective Global Assessment(PG-SGA)is a widely used tool developed to detect malnutrition.The aim of this study was to compare the value of the PG-SGA and objective nutrition assessment parameters,in order to identify a better predictive index for malnutrition in elderly patients with CRC.Methods A total of 131 elderly patients(age≥60 years)with CRC were included and were evaluated for their individual nutritional status using the PG-SGA.Anthropometric and serological indicators were also assayed within 48 h of admission to the hospital.Body composition analysis was implemented by bioelectrical impedance analysis(BIA)instrument.The Chi-squared test,univariate and multivariate logistic regression analysis,or Spearman’s rank correlation analysis were used to determine the differences among the above indices and parameters with regard to predicting malnutrition.Results According to the PG-SGA score,the incidence of total malnutrition in elderly patients with CRC was 80.92%(PG-SGA score≥2),which increased with age.It was found that 28%of the patients with PG-SGA classification A(PG-SGA score 0-1)had a low fat-free mass index(FFMI).Compared with those with PG-SGA A,patients with PG-SGA C PG-SGA score≥9)showed an increased neutrophil to lymphocyte ratio(NLR)and an increased platelet and lymphocyte ratio(PLR)(median=1.78 VS.2.35,P=0.015 and median=108.8 VS.141.6,P=0.001,respectively).In terms of objective nutrition assessment parameters,severely malnourished CRC patients had significantly lower values of serum albumin(ALB),and retinol conjugated protein(RBP)than those who were well-nourished[(38.35±4.84)g/L VS.(40.56±3.44)g/L,P=0.039 and(30.31±15.83)mg/L VS.(39.01±11.95)mg/L,P=0.033,respectively].The Spearman’s rank correlation analysis showed that the PG-SGA findings had positive correlations with the NLR and PLR;while it had negative correlations with the FFMI,body mass index(BMI),ALB,prealbumin,and RBP.Conclusions In clinical practice,a comprehensive nutritional diagnosis,including the PG-SGA score and these objective indicators,can avoid the underdiagnosis of malnutrition,and is more suitable to detect malnutrition(as well as its causes)in elderly patients with CRC.

Low Phase Angle Predicts Poor Survival in Patients with Hepatocellular Carcinoma:A Retrospective Study

Background The phase angle(PA)is an indicator of nutritional status derived from bioelectrical impedance analysis(BIA).Studies have shown that the PA is one of several factors related to the survival of cancer patients.However,the correlation between the PA and prognosis in patients with hepatocellular carcinoma(HCC)has not been reported.This study aimed to explore the relationship between the PA,nutrition-related indicators,and patient prognosis.Methods The data from 248 HCC patients who underwent BIA between January 2015 and December 2019 at the First Hospital of Jilin University were retrospectively analyzed.Patients were divided into two groups according to the median PA value,then the nutrition-related indicators and overall survival(OS)were compared between the two groups.The correlations between the PA and laboratory test nutrition-related indicators and the results of a body composition analysis were determined using Pearson correlation analysis.Independent predictors of the patient prognosis were identified using univariate and multivariate analyses.Results The median OS in the high and low PA groups were 70 and 54.6 months,respectively(P=0.004).The Pearson correlation analysis revealed that the PA was associated with both laboratory test nutrition-related indicators and the results of a body composition analysis.The multivariable Cox regression analysis identified the PA as an independent risk factor affecting the prognosis of patients with Barcelona Clinic Liver Cancer stage A or B.Conclusion The PA is a good biomarker for the nutritional status.We found that the PA was associated with the prognosis in patients with HCC,with a low PA indicating a poor nutritional status and worse prognosis.

Effects of annealing condition and Al content on novel Fe_(73.5)Si_(13.5)B_9Cu_1Nb_(3-x)Al_x alloys

The annealing condition, AI content, and field amplitude dependences of the complex permeability for Nb-poor Finemet type alloys, Fe73.5Si13.5B9Cu1Nba-xAlx （x = 0, 0.5, 1.5, 2.0, and 3.0）, were investigated using an impedance analyzer and X-ray diffraction. The results show that different AI contents lead to different optimum annealing conditions, and the A1 content exerts a distinct effect on microstructure thus resulting in a variety of real permeability value. For the samples annealed at 793 K for 0.5 h, the real permeability increases with an increase in A1 content when the AI content is below 2.0 at.%; as for those annealed at 793 K for 1 h and at 813 K for 0.5 h, an overall increase in real permeability can be obtained compared to those annealed at 793 K for 0.5 h. The permeability under different field amplitudes is also studied and it is found that the relaxation frequency in the lower frequency region tends to moving toward a higher frequency with an increase in field amplitude. All these might be because of the role of Nb in the annealing process and the solubility of AI in the amorphous matrix and nanocrystallized crystallites.

Drinking a Structured Water Product on Markers of Hydration,Airway Health and Heart Rate Variability in Thoroughbred Racehorses:a Small-scale,Clinical Field Trial

Racehorses in training are in situations of repeated stress that may have effects on hydration and health.It was hypothesized that daily consumption of a structured water(SW)product for 4 weeks will result in improved hydration,improved upper airway health and increased heart rate variability.Two groups of Thoroughbred racehorses matched for physiological,training and racing attributes were studied for 4 weeks.One group(n=17)received 10 L(about 15%)of their daily water as SW(followed by ad libitum filtered deep well water)and the control group(n=15)only filtered deep well water.Blood samples and bioelectrical impedance analysis(BIA)measures were obtained at baseline,2 and 4 weeks.Hydration was assessed using BIA.The upper airway was assessed by nasopharyngeal endoscopy at baseline and weekly within 60 minutes of breezing.On weekly breeze days heart rate was recorded at rest,during exercise and recovery and data were analysed for heart rate variability.Compared to controls,horses drinking SW showed increased hydration improved upper airway health post-breezing and increased heart rate variability.It is concluded that drinking 10 L daily of SW increased hydration and may have conferred some wellness benefits.

Application of the Phase Angle in Patients with Malignant Tumors

Bioelectrical impedance analysis(BIA)is a noninvasive and reproducible technique for assessing changes in body composition and nutritional status.The phase angle(PA),a major parameter of BIA,is one of the most sensitive indicators used to detect malnutrition in patients,and is also a prognostic marker in various clinical diseases.The incidence of malnutrition in cancer patients is high,and malnutrition seriously affects the treatment process and prognosis of patients.Reasonable and effective nutritional interventions are therefore of great significance for cancer patients.Compared with traditional nutritional assessment tools,the PA has unique advantages in the nutritional assessment,efficacy monitoring and prognostic prediction of patients with malignant tumors,and it has broad application prospects in clinical practice.This article reviews the research progress on the application of the PA in patients with malignant tumors to provide clinicians with a tool to predict malnutrition,and provide a more favorable basis for the nutritional assessment,treatment and prognostic prediction of cancer patients.

Influence of TiO_2 on the electrochemical performance of pasted typeβ-nickel hydroxide electrode in alkaline electrolyte

Nickel hydroxide was used as the positive electrode material in rechargeable alkaline batteries, which plays a significant role in the field of electric energy storage devices. β-nickel hydroxide（β-Ni（OH）2 ） was prepared from nickel sulphate solution using potassium hydroxide as a precipitating agent. Pure β-phase of nickel hydroxide was confirmed from XRD and FT-IR studies. The effects of TiO2 additive on the β-Ni（OH）2 electrode performance are examined. The structure and property of the TiO2 added β-Ni（OH）2 were characterized by XRD, TG-DTA and SEM analysis. A pasted–type electrode is prepared using nickel hydroxide powder as the main active material on a nickel sheet as a current collector. Cyclic voltammetry and electrochemical impedance spectroscopy studies were performed to evaluate the electrochemical performance of the β-Ni（OH）2 and TiO2 added β-Ni（OH）2 electrodes in 6 M KOH electrolyte. Anodic（Epa） and cathodic（Epc）peak potentials are found to decrease after the addition of TiO 2 into β-Ni（OH）2 electrode material. Further,addition of TiO2 is found to enhance the reversibility of the electrode reaction and also increase the separation of the oxidation current peak of the active material from the oxygen evolution current. Compared with pure β-Ni（OH）2 lectrode,TiO2 added β-Ni（OH）2 electrode is found to exhibit higher proton diffusion coefficient（D） and lower charge transfer resistance. These findings suggest that the TiO2 added β-Ni（OH）2 electrode possess improved electrochemical properties and thus can be recognized as a promising candidate for the battery electrode applications.

Resonance Mechanism Analysis of Large-scale Photovoltaic Power Plant

To analyze the resonance mechanism of a photovoltaic(PV)power plant,a simplified impedance model of the PV power plant is first established.The structure of the PV power plant is then introduced,and the reason for the resonance is obtained by analyzing the on-site situation and measured data of the PV power plant.Finally,a simple and effective solution is proposed based on the structure of the PV power plant and its existing facilities.The results of the engineering experiments and the stable operation of the PV power plant verify the effectiveness of the proposed method.

DIELECTRIC,FERROELECTRIC,PIEZOELECTRIC AND IMPEDANCE STUDY OF LEAD-FREE CERAMIC:SrBi_(4)Ti_(3.975)Zr_(0.025)O_(15)

Polycrystalline SrBi_(4)Ti_(3.975)Zr_(0.025)O_(15)(SBTZ)was prepared using solid-state reaction technique.SBTZ was characterized by X-ray diffraction(XRD)and scanning electron microscopy(SEM).XRD analysis indicated the formation of a single-phase orthorhombic structure.Particle size was found using SEM.The dielectric,ferroelectric,piezoelectric,modulus and impedance spectroscopy studies on SBTZ were investigated in the frequency range 1Hz-1MHz from room temperature(RT)to 600℃.Piezoelectric charge and electromechanical coupling coefficients were calculated from resonance and anti-resonance frequencies.Impedance and modulus plots were used as tools to analyze the sample behavior as a function of frequency.Cole-Cole plots showed a non-Debye relaxation.Conductivity measurements were performed on SBTZ.