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Effect of Firing Temperature on the Electromagnetic Properties of Electronic Transformer Cores Developed by Using Nanosized Mn–Zn Ferrite Powders

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Acta Metallurgica Sinica(English Letters) 2015年第2期28卷 159-163页

作者： Hassan Waqas Ammad Hussain Qureshi Muhammad Shahzad Materials division Directorate of Technology PINSTECH

Current investigation deals with the effect of grain growth process as a function of sintering temperature on the electromagnetic properties （initial permeability, impedance, and gain） of Mn-Zn ferrite （MZF） cores （toroids）. By employing auto combustion process, nanosized [（20 ± 5） nm] MZF powders were synthesized and toroid shape cores were obtained after subsequent calcination and firing （sintering） process. It was observed that the submicron structure （0.5 μm） achieved in the ferrite core sintered at 1,000 ℃ was gradually transformed into micron size grains by increasing the firing temperature i.e., 1,100, 1,200, and 1,350 ℃. The results reveal that MZF core sintered at low temperature （1,000 ℃） showed high impedance, low initial permeability, and narrow working frequency range i.e., 3-15 MHz. However, the improvement in initial permeability, sintered density, and operational frequency range （100 kHz-17 MHz） was observed at high temperature （1,350 ℃） firing in the inert environment. This synthesized MZF core is more suitable for miniaturized switch mode power supply applications.

关键词： Mn-Zn ferrites Nanosized powders Impedance Sintering

pH effect on the formation of THM and HAA disinfection byproducts and potential control strategies for food processing

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Journal of Integrative Agriculture 2017年第12期16卷 2914-2923页

作者： Yen-Con Hung Brian W.Waters Veerachandra K.Yemmireddy Ching-Hua Huang Department of food Science and technology The University of Georgia Department of food Science and technology The Ohio State University School of Civil and Environmental Engineering Georgia Institute of Technology

Chlorine-based sanitizers have seen wide spread use in food sanitation. The reaction of chlorine species with organic matter is a concern for two reasons. Available chlorine can be “used up” by organic compounds resulting in a lower amount of chlorine available for disinfection. Another concern is that some forms of chlorine can react with some organic compounds to form toxic halogenated disinfection byproducts（DBPs）. Many studies have been conducted to evaluate the role of hypochlorous acid（HOCl） and hypochlorite ion（OCl–） in the production of DBPs with a particular interest in the production of trihalomethanes（THMs） and haloacetic acids（HAAs）. Since most of the chlorine reactions are pH dependent, pH is found to have a significant effect on the formation of chlorine DBPs. In many cases, the concentration of THMs decreases and HAAs increases as pH decreases. pH also plays an important role in the determination of the type and amount of DBPs formed, with lower, more acidic, pHs resulting in the formation of less chloroform. This review summarizes the information from the literature on the role of chlorine-based sanitizers as affected by pH in the formation of different types of DBPs. Alternative novel strategies to minimize the formation of DBPs are also discussed.

关键词： sanitizer chlorine disinfection byproducts pH hypochlorite

Hot air treatment activates defense responses and induces resistance against Botrytis cinerea in strawberry fruit

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Journal of Integrative Agriculture 2016年第11期15卷 2658-2665页

作者： JIN Peng ZHENG Cong HUANG Yu-ping WANG Xiao-li LUO Zi-sheng ZHENG Yong-hua College of food Science and technology Nanjing Agricultural University College of Life Science and food Engineering Huaiyin Institute of Technology College of Biosystems Engineering and food Science Zhejiang University

The effect of hot air（HA, 45°C, 3.5 h） treatment on reducing gray mold caused by Botrytis cinerea in strawberry fruit and the possible mechanisms were investigated. The results showed that HA treatment significantly reduced lesion diameter and enhanced activities of chitinase（CHI）, β-1,3-glucanase and phenylalanine ammonia-lyase（PAL） in strawberry fruit. Total phenolic contents were also increased by HA treatment. The activities of antioxidant enzymes including superoxide dismutase（SOD）, catalase（CAT） and ascorbate peroxidase（APX） were higher in HA treated strawberry fruit than those in control. Expression of three defense related genes such as CAT, CCR-1 allele and PLA6 was greatly induced in HA treated strawberry fruit with or without inoculation by B. cinerea. In addition, the in vitro experiment showed that HA treatment inhibited spore germination and tube growth of B. cinerea. These results suggested that HA treatment directly activated disease resistance against B. cinerea in strawberry fruit without priming response and directly inhibiting growth of B. cinerea.

关键词： strawberry hot air postharvest disease induced resistance Botrytis cinerea

Gold nanoparticle-based paper sensor for ultrasensitive and multiple detection of 32 （fluoro）quinolones by one monoclonal antibody

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Nano Research 2017年第1期10卷 108-120页

作者： Juan Peng Liqiang Liu Liguang Xu Shanshan Song Hua Kuang Gang Cui Chuanlai Xu State Key Laboratory of food Science and technology Jiangnan University Wuxi 214122 China School of food Science and technology Jiangnan University Wuxi 214122 China

For rapid and simultaneous detection of （fluoro）quinolones, a broadly specific monoclonal antibody （mAb） that recognizes 32 （fluoro）quinolone antibiotics was prepared using a mixture of a norfloxacin derivative and a sarfloxacin derivative as the hapten. An immunochromatographic strip based on gold nanoparticles （AuNPs） was then assembled with goat anti-mouse antibody and antigen （sarfloxacin coupled to ovalbumin）, used to form the C line and T line, respectively. This antigen competes with the （fluoro）quinolones in a sample incubated with mAbs labeled with AuNPs. The strip can detect 32 （fluoro）quinolones including oxolinic acid, nalidixic acid, miloxacin, pipemidic acid, piromidic acid, rosoxacin, cinoxacin, norfloxacin, pefloxacin, lomfloxacin, enofloxacin, fleroxacin, ciprofloxacin, enrofloxacin, dafloxacin, orbifloxacin, sparfloxacin, gemifloxacin, besifloxacin, balofloxacin, gatifloxacin, moxifloxacin, nadifloxacin, ofloxacin, marbofloxacin, flumequine, pazufloxacin, prulifloxacin, sarafloxacin, difloxacin, trovafloxacin, and tosufloxacin in milk within 10 min with the naked eye. The cut-off values of the strip range from 1 to 100 ng/mL and the limits of detection are 0.1- 10 ng/mL. The strip does not cross-react with antibiotics including tetracycline, sulfamethazine, ampicillin, erythromycin, aflatoxin B1, or gentamicin. In short, this immunochromatographic strip is a very useful tool for the primary screening of （fluoro）quinolones in milk.

关键词： (fluoro)quinolones gold nanoparticle monoclonal antibody paper sensor

Pesticide food safety standards as companions to tolerances and maximum residue limits

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Journal of Integrative Agriculture 2015年第11期14卷 2358-2364页

作者： Carl K Winter Elizabeth A Jara Department of food Science and technology University of California

Allowable levels for pesticide residues in foods, known as tolerances in the US and as maximum residue limits （MRLs） in much of the world, are widely yet inappropriately perceived as levels of safety concern. A novel approach to develop scientifically defensible levels of safety concern is presented and an example to determine acute and chronic pesticide food safety standard （PFSS） levels for the fungicide captan on strawberries is provided. Using this approach, the chronic PFSS level for captan on strawberries was determined to be 2 000 mg kg-1 and the acute PFSS level was determined to be 250 mg kg-1. Both levels are far above the existing tolerance and MRLs that commonly range from 3 to 20 mg kg-~, and provide evidence that captan residues detected at levels greater than the tolerance or MRLs are not of acute or chronic health concern even though they represent violative residues. The benefits of developing the PFSS approach to serve as a companion to existing tolerances/MRLs include a greater understanding concerning the health significance, if any, from exposure to violative pesticide residues. In addition, the PFSS approach can be universally applied to all potential pesticide residues on all food commodities, can be modified by specific jurisdictions to take into account differences in food consumption practices, and can help prioritize food residue monitoring by identifying the pesticide/commodity combinations of the greatest potential food safety concern and guiding development of field level analytical methods to detect pesticide residues on prioritized pesticide/commodity combinations.

关键词： pesticide residues food safety tolerances maximum residue limits (MRLs) regulation reference dose captan strawberries

Influence of processing on microstructure and electrical characteristics of multilayer varistors

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Journal of Advanced Ceramics 2019年第3期8卷 408-417页

作者： D.SZWAGIERCZAK J.KULAWIK A.SKWAREK Institute of Electron technology Kraków Division

The paper reports on the influence of processing on microstructure and electrical properties of multilayer varistors based on zinc oxide doped with Bi2O3,Sb2O3,Co2O3,MnO,Cr2O3,B2O3,and SiO2.0.5–1 wt%of AlF3–CaB4O7 was used as a new effective sintering *** behavior of green laminates during heating was characterized using differential thermal analysis and a heating *** revealed by XRD,SEM,and EDS methods,the varistor layers are composed of ZnO grains of 1–5μm size,submicrometer spinel and pyrochlore grains situated at the ZnO grain boundaries,and nanometric Bi2O3-rich films surrounding ZnO *** impedance studies carried out in the frequency range of 0.01 Hz–2 MHz at temperatures changing from –30 to 150℃ imply the formation of semiconducting grains and insulating grain *** dependence of dielectric permittivity shows a high plateau at lower frequencies,typical for barrier layer capacitance *** fabricated multilayer varistors show nonlinear current–voltage characteristics with a high nonlinear coefficient of 26–*** breakdown voltage was found to decrease within the range of 66–130 V with sintering temperature increasing from 1000 to 1100℃.Good surge current capability of the varistors was confirmed by the tests using 8/20μs pulses.

关键词： multilayer varistor tape casting microstructure current–voltage characteristic

Gold immunochromatographic sensor for the rapid detection of twenty-six sulfonamides in foods

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Nano Research 2017年第8期10卷 2833-2844页

作者： Yanni Chen Liqiang Liu Liguang Xu Shanshan Song Hua Kuang Gang Cui Chuanlai Xu State Key Laboratory of food Science and technology Jiangnan University Wuxi 214122 China School of food Science and technology Jiangnan University Wuxi 214122 China

A gold immunochromatographic sensor （GICS） was developed for the rapid detection of 26 sulfonamides in honey samples. The sensor was based on a group-specific monoclonal antibody （mAb） that can recognize all 26 sulfonamides. Three haptens （hapten I with a thiazole ring, hapten 2 with a benzene ring, and hapten 3 with a straight carbon chain） were used for antigen preparation. With hybridoma technology, a group-specific mAb was screened with a 50% maximal inhibitory concentration （IC50） against sulfathizole （STZ） and the other 25 analogues ranging from 0.08 to 90.18 ng/mL. Mono-dispersed gold nanoparticles were conjugated with the mAb to develop the lateral immunochromatographic strip. A labeled antibody concentration of 0.1 pg/mL and a coating antigen concentration of 0.2 μg/mL in the test line were chosen for strip preparation. Under optimized conditions, the visual limits of detection （vLOD） for the concentrations of STZ, sulfamethoxazole, sulfamethizole, sulfadiazine, sulfamerazine, sulfadimethoxine, sulfamonomethoxine, sulfameter, sulfamethoxypyridazine, and sulfachloropyridazine were 5, 0.25, 0.25, 10, 5, 10, 25, 2.5, 5, 0.25, and 10 μg/kg, respectively. Scanner analysis in honey samples revealed good performance for detection of the 26 sulfonamides. Commercial honey samples were tested with the sensor and positive results were confirmed with high-performance liquid chromatography. The proposed strip sensor provides a convenient method for the rapid and reliable determination of sulfonamides pollutants in honey samples.

关键词： sulfonamides gold immunochromatographic sensor monoclonal antibody honey samples

Determination of antifungal volatile organic compounds of upland rice vinegar and their inhibition effects on Aspergillus flavus in dried chili pepper

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food Bioscience 2022年第2期46卷 308-314页

作者： Ruttipron Pothimon Warawut Krusong Pawinee Daetae Sumate Tantratian Maria Gullo division of Fermentation technology School of Food IndustryKing Mongkut’s Institute of TechnologyLadkrabangBangkok10520Thailand Department of food technology Faculty of ScienceChulalongkorn UniversityBangkok10330Thailand Department of Life Sciences University of Modena and Reggio EmiliaItaly

Determination of volatile organic components(VOC)produced in high acid upland rice vinegar was conducted using *** acid and ethyl acetate at 9.11%and 2.69%(v/v),respectively,were major VOC found in the vinegar while the others were isobutyl acetate,isobutyl alcohol,isoamyl acetate,isoamyl alcohol,phenethyl acetate and phenethyl ***,vinegar and VOC were tested,in vitro,for their inhibition on conidia germination of 10^(3) conidia/mL of Aspergillus *** exposure with 10%(v/v)of vapor-phase vinegar and pure acetic acid completely inhibited the germination of conidia with 30 min exposure,while VOC mixture of 9.11%(v/v)acetic acid,0.08%(v/v)isoamyl alcohol,0.45%(v/v)phenethyl alcohol and 0.01%(v/v)isobutyl alcohol with 45 min exposure could achieve the same ***,vinegar vapor was tested on the inhibition of conidia germination and aflatoxin production of *** during 90 d subsequent storage of dried chili *** inhibition of conidia germination and aflatoxin production were achieved with the 40 min exposure of 1.04±0.03 mmol/L of vaporized *** results showed that fumigation of upland rice vinegar containing antifungal VOC is a simple and an economical method for commercial preservation of dried chili *** rice vinegar is a novel bio-fumigant for prevention of mycotoxin production in dried food and feed products during storage.

关键词： Acetic acid Aspergillus flavus Volatile organic compounds Acetification process

DEM simulation of influence of parameters on energy and degree of mixing

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Particuology 2011年第4期9卷 406-413页

作者： Simo Siiri Jouko Yliruusi division of Pharmaceutical technology University of HelsinkiFinland

Powder mixing is being modeled using a simulation based on Newtonian mechanics. Variables under consideration include particle friction and the amplitude, frequency, and direction of shaking. Trajectories for each particle were recorded, and a mixing degree was calculated for each simulation, for which the average energy transferred into the powder system was recorded and compared to the resulting mixing degree. Mixing of particles originally located near the bottom was studied separately, as was the mixing of particles near the surface. This study shows that choosing the proper mixing parameters not only enhances the final result of mixing, but also yields good results with less strain on the material mixed and on the mixing device.

关键词： Simulation Mixing Mixing degree Energy