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dielectric spectroscopy as a potential technique for prediction of kiwifruit quality indices during storage

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Information Processing in Agriculture 2019年第4期6卷 479-486页

作者： Atefeh Fazayeli Saadat Kamgar Seyed Mehdi Nassiri Hassan Fazayeli Miguel de la Guardia Biosystems Engineering Department Shiraz UniversityShirazIran School of Computer Science Universiti Sains Malaysia 11800 USMPulau PinangMalaysia Department of Analytical Chemistry University of Valencia46100 BurjassotSpain

dielectric spectroscopy has been employed as a simple,low cost and a non-destructive way for prediction of some physicochemical indices of kiwifruit during storage.A parallel-plate capacitor was developed and supplied with sinusoidal voltage waves within a frequency range of 40 kHz–20 *** properties of samples were measured by the dielectric ***,changes associated with fruit ripening properties,including firmness,total soluble solid(TSS)and pH were determined as a function of time at 2*** results showed that storage time significantly affected the quality characteristics of *** neural networks(ANNs)were employed to develop models for prediction of quality indices from dielectric properties at the swept *** property features were selected as inputs while the quality indices including firmness,TSS and pH were chosen as output for the *** obtained models were able to predict the firmness,soluble solids content,and pH of kiwifruit *** predictive models,an ANN with a topology of 20-19-1 gave a perfect capability to predict the kiwifruit firmness with R2 value of *** of this research show that this technique can be used as an efficient and non-destructive method for kiwifruit quality evaluation and monitoring the ripening.

关键词： Kiwifruit dielectric spectroscopy Firmness Total soluble solids pH

dielectric spectroscopy Study on Vesicles of CTAB/SDBS System

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Chinese Chemical Letters 2001年第1期12卷 91-94页

作者： Su Xiang WEI Ying LI Kong Shuang ZHAO Department of Chemistry South China Normal UniversityGuangzhou 510631

Amphiphilic molecules can form into different structures, such as micelle, microemulsion, vesicle, liposome, liquid crystals, and so on by self-associating. The dielectric spectroscopy (DS) method has been applied to the systems of micelle and microemulsion successfully. For the first time the author put the method to the system of vesicle of CTAB/SDBS. The experiments show clear dielectric relaxation and the results were discussed primarily.

关键词： dielectric spectroscopy vesicle macroscopic relaxation time

Determination of the oxidative stability of olive oil using an integrated system based on dielectric spectroscopy and computer vision

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Information Processing in Agriculture 2019年第1期6卷 20-25页

作者： Alireza Sanaeifar Abdolabbas Jafari Department of Biosystems Engineering Shiraz UniversityShirazIran Lincoln Agritech Ltd. Lincoln UniversityLincolnNew Zealand

During storage,olive oil may suffer degradation leading to an inferior quality level when purchased and *** stability is one of the most important parameters for maintaining the quality of olive oil,which affects its acceptability and market *** current methods of predicting the oxidative stability of edible oils are costly and *** aim of the present research is to demonstrate the use of dielectric spectroscopy integrated with computer vision for determining the oxidative stability index(OSI)of olive *** most effective features were selected from the extracted dielectric and visual features for each olive oil *** machine learning techniques were employed to process the raw data to develop an oxidative stability prediction algorithm,including artificial neural network(ANN),support vector machine(SVM)and multiple linear regression(MLR).The predictive models showed a great agreement with the results obtained by the Rancimat instrument that was used as a reference *** best result for modelling the oxidative stability of olive oil was obtained using SVM technique with the R-value of *** can be concluded that this new approach may be utilized as a perfect replacement for quicker and cheaper assessment of olive oil oxidation.

关键词： Computer vision dielectric spectroscopy Olive oil Oxidative stability index

Piezoresponse force microscopy and dielectric spectroscopy study of Ba_(0.6)Sr_(0.4)TiO_(3)thin films

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Journal of Advanced dielectrics 2019年第3期9卷 29-35页

作者： Dionizy Czekaj Agata Lisińska-Czekaj Department of Materials Engineering and Welding Faculty of Mechanical Engineering Gdansk University of Technology 11/12 Narutowicza St.Gdansk 80-233Poland

Research on synthesis,characterization and determination of processing-structure-property relationships of commercially important ferroelectric thin films has been *** sol-gel type solution deposition technique was applied to produce good quality thin films of Ba_(0.6)Sr_(0.4)TiO_(3)(BST60/40)chemical composition on the stainless steel *** thin films were characterized in terms of their microstructure,crystal structure,phase composition,piezoelectric and dielectric *** was found that the BST60/40 thin film adopted the cubic structure at room temperature with an elementary cell parameter a-3:971e8TÅ.Morphology of the thin film surface was studied with Atomic Force Microscopy(AFM).Average roughness of the thin films surface was found(Sa=0:055μm).Piezoresponse Force Microscopy(PFM)was applied for the thin film *** piezoelectric regions were found in BST60/40 thin ***,dielectric response measured at room temperature was studied in assumption of piezoelectric electric equivalent circuit.

关键词： Thin film Ba_(0.6)Sr_(0.4)TiO_(3) crystal structure dielectric spectroscopy piezoresponse force microscopy

Primary Study on Crop Wet Biomass Measuring with dielectric spectroscopy

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Primary Study on Crop Wet Biomass Measuring with Dielectric ...

dielectric,impedance,modulus spectroscopy and AC conductivity studies on novel organic ferroelectric diisopropylammonium chloride(dipaCl)

The 2010 International Conference on Manufacturing Science and Materials Engineering(ICMSME 2011)

作者： Hua Zhang Baiyu Wu Ruifeng Hou Dazhou Zhu Dayu Pan Kun Bi Cheng Wang Mechanical engineering and automation academy of Shang Hai University National Research Center of Intelligent Equipment for Agriculture

Crop wet biomass measuring with dielectric spectroscopy is a non-destructive method to quickly and accurately estimate plant biomass in situIt optimizes the management of agronomistsAn electrostatic free-space system was designed and tested to estimate crop wet biomass in situIt acts as a parallel plate capacitorThe appropriate size of plate of the system is determined through Finite element analysis（FEA）Water is used to make the exclusion of interference at the earlier stage of the experiment, and Wheat is the experiment materialResults from the measuring system showed The Susceptance through the system was strongly correlated with wet biomassThe coefficient of determination（r2） is greater than 0.9.

关键词： biomass dielectric spectroscopy Finite element analysis(FEA).Free-space antennae

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Journal of Advanced dielectrics 2021年第4期11卷 18-26页

作者： Mamataj Khatun Ekramul Kabir Department of Physics Aliah UniversityNewtown Campus Kolkata 700160India Department of Physics Darjeeling Govt.College Darjeeling 734101India

Organic molecular ferroelectric diisopropylammonium chloride(dipaCl)was successfully synthesized using diisopropylamine,hydrochloric acid(57%)and methanol *** permittivity,impedance,modulus spectroscopy and conductivity were systematically studied by Capacitance-Conductance(CP-G)measurements in the temperature range of 373-445 *** property tests clearly show that the organic molecular ferroelectric dipaCl obeys Curies-Weiss law 1/e=(T-T0)/*** real(Z′)and imaginary(Z″)parts of the electrical modulus were calculated from the various values of e′and e″.It is shown that AC conductivity satisfies the relation s(w)∞wn,where the power exponent n depends on temperature and *** Arrhenius equation,the activation energies Es and Eh are also calculated which describes the complete conduction mechanism of dipaCl.

关键词： Molecular ferroelectrics dielectric spectroscopy impedance spectroscopy conductivity

Electric field-induced phase transition from the glasslike to paraelectric phase and dielectric spectra hardening in PMN single crystal

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Journal of Advanced dielectrics 2023年第2期13卷 1-5页

作者： E.Koroleva A.Molokov S.Vakhrushev Ioffe Institute Polytekhnicheskaya 26194021St.-PetersburgRussia

One of the key points in the physics of the relaxors is their response to the applied DC *** studies of this topic were made,in particular on the influence of the field on the dielectric ***,practically,in all the cases,the measurements were performed at a fixed frequency and usually with the change in the temperature at the fixed field *** this paper,we report the evolution of the dielectric spectra at low frequencies(0.1 Hz<ω<1 kHz)at fixed temperature 246 K on changing the DC electric field applied in(111)from 1 kV to 7 ***-Cole function was used to describe the spectra and the field dependences of the mean relaxation timeτ,the oscillation strengthΔεand the width parameterαwere *** obtainedτ(E)andΔε(E)provide evidence of the field-induced transition from the nonpolar glass-like phase to the nonpolar paraelectric phase at around 1.5 kV/*** the paraelectric phase,very fast hardening of the spectra was observed withτchanging from 10 s to about 10−4 *** performed analysis demonstrated that the earlier reported positive C-V effect is completely determined by the spectra hardening,whileΔεdoes not show any change in the glass-like phase and monotonously decreases with a field increase in the paraelectric *** complete understanding of the microscopic origin of the observed phenomena,a detailed study on the short-and long-range structures at the same condition is necessary.

关键词： Relaxor ferroelectrics dielectric spectroscopy phase transition lead magnoniobate

dielectric Investigations on How Mg Salt Is Dispersed in and Released from Polylactic Acid

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Chinese Journal of Polymer Science 2014年第4期32卷 497-508页

作者： Yu-jie Cao 朱丹 To Ngai Ling Qin Chi Wu Jian Shen Jiangsu Key Laboratory of Bio-functional Materials College of Chemistry and Materials ScienceNanjing Normal University Department of Chemistry The Chinese University of Hong Kong The Musculoskeletal Research Laboratory Department of Orthopaedics and TraumatologyThe Chinese University of Hong Kong

Composite biomaterials made of biodegradable polylactic acid （PLA） and bioactive magnesium （Mg） salt are developed for orthopaedic implants or metal implant coatings. The releasing of Mg salt into the biological environment benefits the bone growth, while with the releasing of Mg salt and degradation of PLA there forms a porous scaffold for tissue engineering. The size and morphology of the salt and voids are adjustable with such preparation conditions as salt content, pH of casting solution, and the solidification rate, so that we can control the salt releasing and degradation rate of PLA. dielectric spectroscopy is used to investigate the dispersive structures of Mg salt and voids in the polymer matrix and to monitor the in situ releasing of Mg salts in the simulated body fluid （SBF）. The current study provides us with an orthopedic biomaterial with controllable multi-phase structures, and a tool to investigate the in vivo behaviors of biomaterials.

关键词： dielectric spectroscopy Inorganic-polymer composite Orthopaedic biomaterials Biodegradation Bioactivity.

Structure evolution,dielectric,and conductivity behavior of(K_(0.5)Na_(0.5))NbO_(3)-Bi(Zn_(2/3)Nb_(1/3))O_(3) ceramics

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Journal of Advanced Ceramics 2021年第4期10卷 809-819页

作者： Tianxiang YAN Kaiyuan CHEN Chengqi LI Min LIU Jie WANG Liang FANG Laijun LIU College of Mechanical and Control Engineering&College of Materials Science and Engineering Guilin University of TechnologyGuilin 541004China Institute of Fluid Engineering Equipment Jiangsu Industrial Technology Research InstituteJiangsu UniversityZhenjiang 212013China Key Laboratory for RF Circuits and Systems Ministry of Education&Key Laboratory of Large Scale Integrated DesignHangzhou Dianzi UniversityHangzhou 310018China

(1-x)K_(0.5)Na_(0.5)Nb0_(3-x)Bi(Zn_(2/3)Nb_(1/3))0_(3)((1-x)KNN-xBZN,x=0.010,0.015,0.020,0.025,and 0.030)lead-free ceramics were fabricated via a traditional solid-state *** crystal structure,microstructure,dielectric,and conductivity behavior of this system were *** with X-ray diffraction(XRD)patterns,Rietveld refinement,and dielectric spectroscopy,an orthorhombic phase was determined for x=0.010,an orthorhombic-tetragonal mixed phase was identified for x=0.015,and a rhombohedral symmetry appears in 0.020≤x≤*** 0.98KNN-0.02BZN and 0.975KNN-0.025BZN ceramics exhibit stable permittivity and low dielectric loss tangent(tan)in wide temperature ranges owing to the combination of rhombohedral-tetragonal step-like feature and the diffuse phase transition from tetragonal to *** activation energies of dielectric relaxation and conductivity behavior at high temperatures initially decrease slightly,then drop sharply,and finally decline slowly,which could be attributed to microstructure morphologies and the concentration of oxygen vacancies.

关键词： ceramic crystal structure dielectric spectroscopy oxygen vacancies