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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
51

Avaliação das técnicas TDR (Reflectometria por Domínio do Tempo) e moderação de nêutrons, na determinação do teor de água em diferentes classificações do solo /

Batista, Wagner Roberto, 1975- January 2004 (has links)
Orientador: João Eduardo Guarnetti dos Santos / Banca: Marcos Roberto Bormio / Banca: Gastão Moraes da Silveira / Resumo: Este trabalho foi desenvolvido nas dependências das Fazendas Lageado e Edgárdia, pertencentes à Faculdade de Ciências Agronômicas - UNESP de Botucatu-SP, no município de Pratânia e no distrito de Vitoriana, município de Botucatu-SP, com o objetivo de avaliar 2 técnicas de obtenção do teor de água no solo. A primeira delas é conhecida como moderação de nêutrons, que consiste na emissão de nêutrons rápidos e contagem de nêutrons moderados retornados após colisão, com moléculas de hidrogênio encontradas no solo. A partir da contagem obtida, estabeleceu-se uma correlação entre essa contagem e o teor de água no solo obtido pelo método gravimétrico, tomado como padrão. Outra técnica é a do TDR (Time Domain Reflectometry) ou Reflectometria no Domínio de Tempo, onde se determina a constante dielétrica relativa do solo e, por correlação, obtém-se o teor de água correspondente. Esta técnica foi desenvolvida de 2 maneiras: na primeira, manteve-se a calibração geral conhecida como Equação de Topp, que consiste numa Equação polinomial cúbica, obtida de forma empírica. E, na segunda, desenvolveu-se uma calibração específica para cada solo analisado. Foram avaliados 7 tipos de solos às profundidades de 15 e 30cm respectivamente com 3 variações de textura: arenosa, média e argilosa. Também, determinou-se variáveis físicas, como densidade de partículas e análises químicas, dando ênfase no teor de matéria orgânica. O trabalho de campo consistiu no levantamento de dados (contagens) com a sonda de nêutrons "in situ" e na obtenção de amostras de solo, nas respectivas profundidades, para análise em laboratório pelas técnicas TDR e gravimétrica. Como referencial ou padrão, utilizou-se o método direto ou gravimétrico para a determinação do teor de água no solo...(Resumo completo, clicar acesso eletrônico abaixo) / Abstract: This work was developed at Fazenda Lageado and Edgárdia areas, belonging to the Agronomics Science School - UNESP Botucatu-SP, in Pratânia borough and in Vitoriana district, both in the Botucatu borough. The main objective was to study and evaluate two techniques to obtain the water content in the soil. The first technique evaluated is known as neutron moderation which consists in the emission of fast neutrons and in the counting of moderate neutrons which came back after a collision with hydrogen molecules found in the soil. From the coint obtained, it was settled the correlation between the count and the water content value in the soil, obtained througth the gravimetric method. Another technique is the TDR (Time Domain Reflectometry). In this, it can be determined the apparent relative constant dielectric in the soil and by the correlation, to reach the correspondent value of water content. This technique was developed in two ways: in the first one, it was kept the general calibration known as Topp's equation which consists in a cubic polynomial equation obtained in an empiric form. The second one, it was developed a specific calibration to each kind of soil analysed. It was evaluated seven kinds of soils to the depths of 15cm and 30cm, respectively. As an initial criterion to the choice of soils, we tried to obtain three texture variations: gritty sandy, mean and mudoy. It was also observed the physical variables such as: particles density and chemical analyses, giving a special emphasis on the drift of organic matter. Basically, the fieldwork consited in data surveys (count) with the neutron probe "in situ" and in the...(Complete abstract click electronic access below) / Mestre
52

Study on Supervision of Wavelength Division Multiplexing Passive Optical Network systems

Cen, Min January 2011 (has links)
The wavelength-division-multiplexed passive optical network (WDM-PON) offers many advantages such as large bandwidth per user, easy management, high network security and low insertion loss enabling long-reach and/or high split-ratio. However, with the rapid development and growing interest for deployment of WDM-PON, the PON systems are becoming increasingly vulnerable to various failures. Therefore, network supervision becomes extremely important to guarantee an appropriate level of network reliability performance. The aim of PON supervision is to provide automated test and diagnostic capability without compromising the available bandwidth for services. An essential function is to detect any kind of deterioration in the network that can cause suspended services and to remotely localize these faults in order to avoid the high cost arising from troubleshooting. In this thesis, we evaluate several existing WDM PON supervision methods, based on which two simple and cost-effective new solutions are proposed to localize fiber failures in WDM PON systems. In the first solution, a conventional optical time domain reflectometry (OTDR) and a switch unit are employed, while in the second method, a novel architecture based on N×N arrayed waveguide grating (AWG) is proposed. Both methods are able to localize failures in feeder fiber and drop fibers without e.g. using expensive tunable OTDRs. A patent has been filed based on the second solution. The first proposed method is validated by simulations using VPI Transmission Maker. According to the results, this supervision method is able to give accurate measurement of many different types of failures that may happen in a fiber link. Furthermore, VPI is examined in terms of its future applicability in modeling complete PON supervision methods based on OTDR.
53

Locating faults in boundary wires for autonomous lawn mowers : An investigative study on methods used to locate faults in underground, low-voltage cables with focus on implementing Time Domain Reflectometer (TDR)

Alhaj Kasem, Mustafa, Andersson, Daniel January 2021 (has links)
Purpose:The purpose of this thesis was to identify a useful solution to find the location of a broken boundary wire. By useful we mean that the solution should be inexpensive, user friendly and accurate. However, this thesis will only investigate the accuracy of the method where the hypothesis is that an investigated method is applicable for all underground wires. Method:This study conducted a literature research in order to investigate what methods that are used in other industries to locate faults in underground, low-voltage electrical wires. After the research, the most commonly used fault locating methods were described and the one that seemed most useful was chosen as a possible solution.For the solution to be useful the accuracy was investigated. The method used to conduct an experiment and gather data to validate the solution was Design Science Research. Result:Three methods were investigated as possible solutions:Time Domain Reflectometry (TDR), Frequency Domain Reflectometry (FDR) and Murray bridge where experiments were conducted using TDR.TDR proved to be unapplicable in locating faults in boundary wires, although it was confirmed to be a valid solution to locate faults in coaxial cables with <1% error margin.What makes TDR and other reflectometry methods unsuitable methods within the autonomous lawn mower industry is the lack of characteristic impedance in the used boundary wires. The hypothesis that an investigated method is applicable for all underground wires is thereby refuted. Limitations:Experiments were conducted in laboratory environment with a signal generator and an oscilloscope. One experiment was conducted on a boundary wire in the ground which provided no reflected signal.
54

Desempenho do reflectômetro no domínio do tempo na detecção de variações de umidade do solo. / Performance of a time domain reflectometer in the detection of soil moisture variations.

Joaquim Júnior, Gilberto Oliveira 21 July 2003 (has links)
O objetivo do trabalho foi avaliar o desempenho do reflectômetro no domínio do tempo (TDR) comparativamente ao tensiômetro com manômetro de mercúrio (considerado como instrumento padrão), dando-se ênfase na sensibilidade de detecção de variações na umidade do solo sob condições de molhamento e secagem. Foi instalado um experimento em um solo classificado como Nitossolo Vermelho distrófico latossólico de textura muito argilosa, localizado próximo ao Posto Meteorológico do Departamento de Ciências Exatas, ESALQ/USP, Piracicaba (SP), Brasil, 22 o 42’ 30’’ de latitude sul e 47 o 38’ 00’’ de longitude oeste. Com dados de um ensaio de determinação da condutividade hidráulica do solo pelo Método do Perfil Instantâneo, de um período de secagem e de inundações intermitentes do solo, analisou-se a concordância entre a constante dielétrica obtido pelo TDR e o potencial matricial da água no solo obtido pelo tensiômetro, além dos valores de umidade volumétrica obtidos pelas mesmas técnicas. Concluiu-se que o desempenho do TDR foi superior ao do tensiômetro sob condições de secagem do solo e na detecção de variações de umidade. / The performance of a time domain-reflectometer (TDR) was compared with a mercury tensiometer (considered to be the norm), emphasizing the detection of variations in soil water content under wetting and drying conditions (as in instantaneous profile method to determine soil hydraulic conductivity). An experiment was performed in a Nitossolo Vermelho distrófico latossólico argiloso (Brazilian classification system), close to the meteorological observatory of the ESALQ/USP, Piracicaba (SP), Brazil, latitude 22 o 42’30’’ S, longitude 47 o 38’00’’ W. Data of matric potential, dieletric constant and water content during a dry period and water application were analyzed. The TDR cable tester was better than the tensiometer to detect the soil moisture variation.
55

Desenvolvimento de sensores baseados em reflectometria no domínio do tempo para análise de combustíveis. / Time domain reflectometry-based sensors development for fuel analysis.

Rodrigues, Daniel Brás Rochinha 05 September 2016 (has links)
Este trabalho apresenta um estudo da técnica da Reflectometria no Domínio do Tempo - TDR, para qualificação de álcool combustível. Há grande interesse na qualificação de combustíveis pois a adulteração é uma prática comum no Brasil e tem implicações nocivas no funcionamento do motor, causa maior poluição ambiental e evasão fiscal. O presente estudo foi focado em etanol adulterado com água, utilizando uma sonda comercial e sondas desenvolvidas neste trabalho, tendo sido dividido em três etapas: a primeira etapa consistiu em confirmar a viabilidade da técnica TDR para o tema proposto utilizando o sensor comercial de umidade de solo VG400 da Vegetronix, enquanto que o segundo passo tratou da simulação de sondas dos tipos bifilar, microstrip, coaxial e helicoidal em simulador tridimensional de eletromagnetismo, visando a escolha e otimização do tipo de sonda a ser usada para a qualificação do combustível. O terceiro e último passo consistiu na fabricação das sondas simuladas escolhidas e na realização de ensaios utilizando amostras de etanol com variadas proporções de água. Este estudo mostrou que a sonda helicoidal, que é uma proposta original deste trabalho, apresentou maior sensibilidade entre os modelos escolhidos, mostrando uma variação de resposta entre as amostras de etanol e água puros 12,5% maior que a sonda bifilar, que é a segunda sonda mais sensível dentre as estudadas. / This work presents a study of the Time-Domain Reflectometry - TDR technique for ethanol fuel qualification. There is a great interest in fuel qualification since adulteration is a common practice, which brings harmful consequences to the vehicle motor functioning, besides causing higher environmental pollution and tax evasion. The present study is focused on the qualification of ethanol adulterated with water, by using a commercial probe and probes developed in this work. It was divided in three steps: the first step has confirmed the viability of the technique for the proposed theme using a commercial sensor Vegetronix VG400 for soil moisture analysis. The second step was the simulation of bifilar, microstrip, coaxial and helical probe geometries using a 3D eletromagnectics software, leading to the optimization of the probe for fuel qualification. The last step was the fabrication of the simulated probes and the test of their performance into alcohol adulterated with various proportions of water. This study showed that the helical probe, an original proposal of this work, presented higher sensibility among the chosen models. Its response variation between pure alcohol and pure water was 12.5% greater than the bifilar probe, which was the second most sensitive sensor among the studied geometries.
56

Estudo da distribuição da solução no solo aplicado por gotejamento enterrado e superficial / Soil solution distribution study applied by subsurface and surface drip irrigation

Barros, Allan Cunha 16 January 2008 (has links)
Em função do número reduzido de estudos sobre o movimento da água e de íons no bulbo molhado, foi realizado este trabalho com o objetivo de avaliar a distribuição de água e concentração de nutrientes no bulbo formado pelo sistema de gotejamento enterrado em comparação ao superficial. O ensaio foi conduzido na área experimental do Departamento de Engenharia Rural da Escola Superior de Agricultura "Luiz de Queiroz" - ESALQ/USP, localizada no município de Piracicaba, SP. Para a avaliação foram abertas trincheiras e instaladas sondas de TDR, para o monitoramento da distribuição da solução, dispostas a 0,5; 0,15; 0,25; 0,35 e 0,45 m - profundidade, e a 0,5; 0,15; 0,25; 0,35 m - comprimento, totalizando 17 sondas em malha por trincheira. A solução de KNO3 foi aplicada a partir de gotejadores com diferentes vazões (2 e 4 L/h), sendo aplicado o volume de 1 L em intervalos de 1 hora, totalizando 10 L de solução por repetição, Conjuntamente ao monitoramento da distribuição da solução no solo, medições da área superficial molhada e do disco saturado foram feitas com régua milimetrada, além disso, foi estabelecido um volume de controle onde foram avaliadas a uniformidade de aplicação de água e KNO3. Desta forma, foi possível verificar que: em relação aos sistemas superficiais, os sistemas enterrados apresentaram menor área superficial molhada e atingiram uma maior largura e profundidade; a umidade inicial do solo influencia a formação do bulbo molhado e o movimento do KNO3 no solo; a uniformidade de sais distribuídos no volume de controle é afetada negativamente pelo aumento do volume aplicado e as maiores concentrações de água e concentração de KNO3 foram obtidas próximas ao ponto de emissão. / In function of the reduced number of studies on the water and ions movement in the wet soil volume, this work was conducted with the goal of evaluating the distribution of water and nutrient concentration in the wetted soil volume formed by subsurface drip irrigation (SDI) in comparison to surface system. The rehearsal was concducted in the experimental area of the Rural Engineering Department - ESALQ/USP, located in Piracicaba, SP. Trenches were opened and installed probes of TDR for studying to solution distribution, to facilitate the study a mesh of probes was disposed to 0,5; 0,15; 0,25; 0,35 and 0,45 m - depth, and to 0,5; 0,15; 0,25; 0,35 m - length, with the total of 17 probes. The solution of KNO3 was applied starting from emitters with different flows (2 and 4 L/h), it was applied the volume of 1 L within intervals of 1 hour, with the total of 10 L of solution for repetition. All together to study the solution distribution in the soil, the wet superficial area measurements and of the saturated disc they were done by the ruler, besides, it was established a control volume where the uniformity application of water and KNO3 was analysed. This way, it was possible to verify that: in relation to the superface systems, the SDI presented smaller wet superficial area and they reached a larger width and depth; the initial soil water content influences the formation of the wetted soil volume and the KNO3 movement in the soil; the salt uniformity, distributed in the control volume, is affected negatively by the applied volume increased, and the largest concentrations of water and KNO3 were obtained close to the emission point.
57

Desenvolvimento de sensores baseados em reflectometria no domínio do tempo para análise de combustíveis. / Time domain reflectometry-based sensors development for fuel analysis.

Daniel Brás Rochinha Rodrigues 05 September 2016 (has links)
Este trabalho apresenta um estudo da técnica da Reflectometria no Domínio do Tempo - TDR, para qualificação de álcool combustível. Há grande interesse na qualificação de combustíveis pois a adulteração é uma prática comum no Brasil e tem implicações nocivas no funcionamento do motor, causa maior poluição ambiental e evasão fiscal. O presente estudo foi focado em etanol adulterado com água, utilizando uma sonda comercial e sondas desenvolvidas neste trabalho, tendo sido dividido em três etapas: a primeira etapa consistiu em confirmar a viabilidade da técnica TDR para o tema proposto utilizando o sensor comercial de umidade de solo VG400 da Vegetronix, enquanto que o segundo passo tratou da simulação de sondas dos tipos bifilar, microstrip, coaxial e helicoidal em simulador tridimensional de eletromagnetismo, visando a escolha e otimização do tipo de sonda a ser usada para a qualificação do combustível. O terceiro e último passo consistiu na fabricação das sondas simuladas escolhidas e na realização de ensaios utilizando amostras de etanol com variadas proporções de água. Este estudo mostrou que a sonda helicoidal, que é uma proposta original deste trabalho, apresentou maior sensibilidade entre os modelos escolhidos, mostrando uma variação de resposta entre as amostras de etanol e água puros 12,5% maior que a sonda bifilar, que é a segunda sonda mais sensível dentre as estudadas. / This work presents a study of the Time-Domain Reflectometry - TDR technique for ethanol fuel qualification. There is a great interest in fuel qualification since adulteration is a common practice, which brings harmful consequences to the vehicle motor functioning, besides causing higher environmental pollution and tax evasion. The present study is focused on the qualification of ethanol adulterated with water, by using a commercial probe and probes developed in this work. It was divided in three steps: the first step has confirmed the viability of the technique for the proposed theme using a commercial sensor Vegetronix VG400 for soil moisture analysis. The second step was the simulation of bifilar, microstrip, coaxial and helical probe geometries using a 3D eletromagnectics software, leading to the optimization of the probe for fuel qualification. The last step was the fabrication of the simulated probes and the test of their performance into alcohol adulterated with various proportions of water. This study showed that the helical probe, an original proposal of this work, presented higher sensibility among the chosen models. Its response variation between pure alcohol and pure water was 12.5% greater than the bifilar probe, which was the second most sensitive sensor among the studied geometries.
58

Interpretação dos resultados de ensaios TDR para a determinação do teor de umidade dos solos / Interpretation of TDR test results for determining the moisture content of soil

Valdivia Calderón, Victor Jack 20 April 2010 (has links)
Este trabalho de pesquisa apresenta uma nova abordagem para calibrar uma sonda helicoidal TDR, usada para medir o teor de umidade do solo. Foi empregada uma aproximação tomando em consideração a interpretação física dos valores de constantes dielétricas. As equações de calibração foram determinadas mediante um modelo dielétrico misto, quais relacionam a constante dielétrica da mistura multifase com a constante dielétrica e frações de volumes dessas componentes. Ensaios realizados em laboratório permitirem o desenvolvimento de duas equações de calibração para a avaliação de teor de umidade volumétrico e gravimétrico dos solos. A calibração foi executada com medições de constante dielétrica em diferentes líquidos e solos, usando uma sonda convencional TDR e a sonda helicoidal TDR. As leituras realizadas com as duas sondas foram depois comparadas. O modelo dielétrico das duas fases permitiu descrever a contribuição dos materiais dielétricos do corpo da sonda helicoidal e os materiais investigados. Mostrou-se que o conhecimento das características físicas e geométricas da sonda TDR usada nos ensaios é de crucial para garantir a qualidade das constantes dielétricas lidas, e conseqüentemente a determinação do teor de umidade in situ. / The objective of this work was to calibrate a coiled TDR probe used to measure the water content of soil. It was used an approach that takes into account a physical interpretation of the values of the dielectric constants. The calibration equations were determined by means of a mixed dielectric model, which relates the dielectric constant of a multi-phase mixture with the dielectric constants and volume fractions of its components. Tests carried out in the laboratory allowed development of two calibration equations for the assessment of the volumetric and gravimetric soil water content. Calibration was performed with measurements of dielectric constants in different liquids and soils, using a conventional TDR probe and a coiled TDR. The readings performed with the two probes were then compared. The dielectric model of two phases permitted describing the contribution of the dielectric material of the body of the probe coil and the materials investigated. It has been shown that knowledge of the physical and geometrical characteristics of the TDR probe used in the tests is crucial for the quality of the dielectric constant readings, and consequently the determination of water content in situ.
59

Avaliação de uma sonda TDR helicoidal para a estimativa do teor de umidade de solos em campo e laboratório / Evaluation of a helicoidal TDR probe to estimate the soil water content in laboratory and in situ

Assis, Cleber Decarli de 09 May 2008 (has links)
Este trabalho de pesquisa apresenta a avaliação de uma sonda TDR helicoidal para estimar o teor de umidade dos solos, em diferentes profundidades, através da técnica da reflectometria no domínio do tempo (TDR). Essa sonda, desenvolvida especificamente para esse fim, foi devidamente calibrada em laboratório para diferentes tipos de solo. O processo de calibração consistiu na determinação da constante dielétrica aparente (Ka) e condutividade elétrica volumétrica (ECb) de um mesmo solo com diferentes teores de umidade. Posteriormente foram buscadas correlações entre Ka e o teor de umidade gravimétrico (w), obtido em estufa. São propostas correlações entre w e Ka, entre w e \'KA POT. 1/2\' e entre teor de umidade volumétrico (\'teta\') e Ka. Também foram consideradas as correlações propostas por Yu e Drnevich (2004), visando estimar também a massa específica seca dos solos. Foram realizados ensaios de campo para a validação das equações de calibração. Os valores dos teores de umidade estimados através da técnica da reflectometria no domínio do tempo, tanto em laboratório como em campo, foram comparados com os valores de teor de umidade obtidos com o método da estufa. Com base nos resultados foram determinados os erros referentes às calibrações. Nos ensaios de campo, os teores de umidade obtidos através da correlação entre w e \'KA POT. 1/2\' apresentaram melhores resultados, quando comparados com aqueles estimados com as outras correlações. Pelos resultados obtidos conclui-se que a técnica TDR é uma alternativa viável para a estimativa em campo do teor de umidade em grandes profundidades. / In this work is presented the evaluation of a recently developed helicoidal probe used for estimating the soil water content through the time domain technology (TDR). This probe has been calibrated in laboratory for different types of soils. The calibration process consisted in assessing the values of the apparent dielectric constant (Ka) and the bulk electric conductivity (ECb) of a specific soil at different levels of water content (w). Subsequently, correlations between the apparent dielectric constant and the water content have been established. The same has done with the bulk electric conductivity. Correlations between Ka and w, \'KA POT. 1/2\' and w, \'teta\' (volumetric water content) and Ka have been proposed. Also, the correlations proposed by Yu and Drnevich (2004) have been considered. To validate the proposed correlations, tests using the helicoidal probe were performed in the field. Estimated values of field water content, using the TDR technology have been compared to the correspondent oven water content values. Based on these comparisons, errors regarding the calibrations have been calculated. In the field tests, the correlations between \'KA POT. 1/2\' and w have presented more accurate results than those obtained with the other correlations. Experimental results have shown that the TDR technology for estimating water content at different depths in the field is feasible and expedite.
60

Möglichkeiten der prozessbegleitenden Charakterisierung von Fleisch auf Basis der dielektrischen Zeitbereichsreflektometrie

Herm, Cornelia 27 November 2013 (has links) (PDF)
Da die dielektrischen Eigenschaften eines jeden Materials, also auch von Fleisch, charakteristisch sind und von Faktoren wie beispielsweise dem Feuchtigkeitsgehalt und der chemischen Zusammensetzung sowie der physikalischen Struktur abhängig sind, gibt es bereits seit einigen Jahren verschiedene Forschungsansätze im Bereich der dielektrischen Messmethoden. Ein neu entwickeltes Messverfahren für die Be-stimmung der Qualitätsparameter Lagerdauer und eventuell erfolgter Gefrierprozesse bei Fisch basiert auf der dielektrischen Zeitbereichsreflektometrie. Die Klärung der Frage, in wie weit dieses Verfahren auch bei Frischfleisch angewendet werden kann, ist das Ziel der vorliegenden Dissertation. In Vorversuchen wurde zunächst die generelle Anwendbarkeit des Verfahrens im Fleischbereich anhand verschiedener Lager- und Gefrierversuche geprüft. Basierend auf diesen Ergebnissen gliederten sich die experimentellen Untersuchungen in fol-gende Abschnitte: Ermittlung der Lagerdauer von SB-verpackten Minutensteaks vom Schweinelachs (MAP) sowie von Hähnchenbrustfilets, Erkennung von Gefrierprozes-sen bei Hähnchenbrustfilets und Schweinelachsen, Gefrierlagerdauerbestimmung verschiedener Fleischsorten (Schweinelachs, Schweinebauch und Rinderbugstück) bei drei unterschiedlichen Gefriertemperaturen und Erkennung von Fremdwasserzu-sätzen bei Hähnchenbrustfilets. Die Vorversuche zeigten eine generelle Eignung des Verfahrens zur Untersuchung von Lagerzeiten und Gefrierprozessen bei Fleisch. Im Bereich der Lagerdauererkennung ist eine Anwendung, auch für SB-verpackte Produkte (in Schutzatmosphäre), denkbar, das Verfahren muss hier allerdings bezüg-lich der zu Grunde liegenden linearen Auswertungsmodelle noch optimiert werden (Kurvenanpassung notwendig). Ebenso konnten gute Ergebnisse in der Gefrierlager-dauerbestimmung erzielt werden, auffällig waren die Fleischsorten-übergreifend bes-seren Ergebnisse der Messungen an vor dem Einfrieren einige Tage gelagerten Pro-ben. Gute Ergebnisse erbrachten auch die Messungen bezüglich der Gefrierprozess-erkennung (Proben frisch, einmal-gefroren und doppelt-gefroren). Ein Einsatz des Verfahrens ist besonders im Geflügelfleischbereich denkbar und angesichts der ge-setzlichen Bestimmungen für Geflügelfleisch (keine Fleischzubereitungen aus gefro-rener und aufgetauter Ware) auch überaus wünschenswert. Die besten Ergebnisse lieferte das Verfahren bei der Fremdwassererkennung an Hähnchenbrustfilets, was auf Grund des starken Dipolcharakters von Wasser bei einem auf Dielektrizität beru-henden Messverfahren auch erklärbar ist. Selbst die zusätzlich mit Geflügelfleisch-Proteinhydrolysatpulver versetzten Proben konnten (bedingt durch die Strukturverän-derungen im Probenmaterial) eindeutig von den unbehandelten Proben abgegrenzt werden, was mittels laborchemischer Analyse über das Wasser-Protein-Verhältnis nicht möglich gewesen wäre. Ein Einsatz des Verfahrens für diese Anwendung erscheint besonders sinnvoll, um der Überwachung und Qualitätssicherung ein ge-eignetes Instrument für die schnelle Feststellung von Wasserzusätzen (bei unverän-dertem Wasser-Eiweiß-Verhältnis) geben zu können. Vor dem praktischen Einsatz dieser Messmethode müssen größere Validierungsver-suche durchgeführt werden, um geeignete Kalibrationssätze für die Anwendung an unbekannten Proben, besonders im Geflügelfleischbereich, zur Verfügung zu haben. Ein Einsatz des Verfahrens zur Qualitätsbestimmung im Fleischbereich ist generell möglich und wäre auf Grund der schnellen Ergebnislieferung und einfachen Handha-bung der (mobilen) Messeinrichtung für Überwachung und Qualitätskontrolle wünschenswert. / As the dielectric properties of each material, thus also for meat, are characteristically and depend on factors as for instance humidity and the chemical composite as well as physical structure there are existing different research approaches in the array of dielectric measurement methods already for many years. A new developed meas-urement method for the estimation of the quality parameters storage time and option-ally occurred freezing processes on fish is basing on the dielectric time domain reflec-tometry. The clarification of the question how far this method can also be used for fresh meat is the intention of the present graduate thesis. In preliminary tests initially the general applicability of the method in the meat sector by means of different storage and freezing examinations was reviewed. Basing on these results the experimental examinations were divided into the following parts: evaluation of the storage time of packaged minute steaks from the pork chop (MAP) as also of chicken breast filets, estimation of freezing processes of chicken breast filets and pork chops, freezing storage time recognition of different meat varieties (pork chop, pork belly and beef bow pieces) with three different freezing temperatures and evaluation of added water in chicken breast filets. The preliminary tests indicated a general ability of the method for the recognition of storage times and freezing processes on meat. In the array of storage time evaluation an appliance, also for MAP-packaged products (in controlled atmosphere), is thinkable, however the method has to be optimized concerning the underlying linear evaluation models (curve fitting is necessary). As well there could be aimed good results for the freezing storage time recognition, the meat variety comprehensive better results for measurements on pattern which were stored some days previously were flashy. Good results were also adduced by the measurements concerning the freezing process recognition (pattern fresh, once- and double-frozen). An application of the technology is notably thinkable for the poultry meat sector and, in the face of the legal requirements for poultry meat (no preparation of frozen and thawed material allowed) also exceedingly desirable. The best results were carried out using the method for the recognition of added water in chicken breast filets, what is explainable by reason of the strong dipole character of water within a measurement method based on dielectricity. Even the pattern additionally glazed with poultry hydrolyzed protein powder could definitely be differentiated from the untreated pattern, what could not be realized with the water protein percentage using a laboratory chemical analysis. After all an appliance of the method for this application seems particularly reasonable, as a suitable instrument for the fast recognition of added water (with an unmodified water-protein-ratio) could be given to the monitoring and quality assurance. Before starting the practically application of this measurement method there have to be accomplished larger validation examinations, to have suitable calibration kits for the application on unknown pattern at one´s disposal, especially in the poultry meat sector. The assignment of the method for quality evaluation in the meat sector is generally possible and would be desirable for the monitoring and quality control by the reason of its fast result delivery and easy handling of the (mobile) measurement arrangement.

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