Segrevanje snovi z mikrovalovi brez konvekcije

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Data

Language:	Slovenian
Year of publishing:	2012
Source:	Ljubljana
Typology:	2.11 - Undergraduate Thesis
Organization:	UL PEF - Faculty of Education
Publisher:	[D. Drašković]
UDC:	54-732(043.2)
COBISS:	9263689
Views:	1420
Downloads:	285
Average score:	0 (0 votes)
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Secondary language:	English
Secondary title:	Heating of matter by microwaves without convection
Secondary abstract:	This thesis considers heating of matter by means of microwaves. The most common device that uses micro waves for the heating of matter is the microwave oven. Because of the microwave ovens ubiquity and accessibility there are many articles that address the way it works and in how it heats matter. However, it appears that articles contradict each other in their claims that the heating of the matter is either from the inside or from the outside. What actually means »heating the material in the oven from the inside or from the outside«. In this experiment the heating substance mostly used is water, because most food contains a high percentage of water it is probably the most heated element. The aim is to study how the material is heated, homogeneously throughout the whole volume or unevenly. If the heating is found to be uneven, which parts are more heated, which are less and why is that so. The first part of this paper defines the problem and the hypothesis. The first hypothesis is that the substance in the microwave heats unevenly. The second hypothesis is that law of absorption of electro magnetic waves also applies for the absorption of microwaves generated in the microwave. For a reader's convenience the second part of the research is designed to explain the nature of electromagnetic waves in general and micro waves in particular. The third section describes how microwave oven's work. The fourth part is the basic theoretical explanation for the absorption of electromagnetic waves and the relationship to the heating of the matter. The fifth part describes the research into different cases of heating materials in the microwave oven and looks at a special case which shows that the law of absorption of electro-magnetic waves is valid. The final part summarises the findings and gives us an insight, gained from the study. The appendix contains tables with results of actual measurements which are displayed in graphs.
Secondary keywords:	physics;fizika;
File type:	application/pdf
Type (COBISS):	Undergraduate thesis
Pages:	32 str.
Type (ePrints):	thesis
Title (ePrints):	Heating of matter by microwaves without convection
Keywords (ePrints):	mikrovalovi
Keywords (ePrints, secondary language):	microwaves
Abstract (ePrints):	Diplomska naloga obravnava segrevanje snovi s pomočjo mikrovalov v mikrovalovni pečici. Najbolj znana naprava, ki uporablja mikrovalove za segrevanje snovi, je mikrovalovna pečica. Zaradi razširjenosti in dostopnosti mikrovalovne pečice je o njenem delovanju in vplivu na segrevano snov napisano veliko prispevkov. Trditve v prispevkih so pogosto nejasne in si tudi nasprotujejo. Nekateri viri trdijo, da se snov segreva od znotraj, drugi spet trdijo, od zunaj. Kaj sploh pomeni segrevanje od znotraj ali od zunaj? Pri raziskavi je za segrevano snov večinoma uporabljena voda, ker jo vsebuje veliko živil in je zaradi tega verjetno najbolj pogosto segrevana snov. Cilj raziskave je ugotoviti, kako se snov segreva: enakomerno po vsej prostornini ali neenakomerno. Če je segrevanje neenakomerno, kateri deli se bolj segrejejo, kateri manj in od česa je to odvisno. V prvem delu diplomske naloge je opredeljen problem in sta postavljeni hipotezi. Prva hipoteza je, da se snov v mikrovalovki segreva neenakomerno. Druga hipoteza je, da tudi za absorpcijo mikrovalov nastalih v mikrovalovni pečici, velja absorpcijski zakon za ravno elektromagnetno valovanje. Zaradi lažjega razumevanja raziskave, je drugi del namenjen spoznavanju elektromagnetnega valovanja in mikrovalov. Tretji del opisuje delovanje mikrovalovne pečice. V četrtem delu so podana osnovna teoretična znanja glede absorpcije elektromagnetnega valovanja in s tem v zvezi segrevanja snovi. Peti del opisuje raziskave različnih primerov gretja snovi v mikrovalovki in poseben primer s katerim je pokazana veljavnost zakona o absorpciji elektromagnetnega valovanja pri ravnem valovanju. V zaključnem delu, so strnjene ugotovitve in spoznanja dobljena pri raziskavi. V prilogi so še priložene tabele z rezultati dejanskih meritev iz katerih so potem narejeni grafi.
Abstract (ePrints, secondary language):	This thesis considers heating of matter by means of microwaves. The most common device that uses micro waves for the heating of matter is the microwave oven. Because of the microwave ovens ubiquity and accessibility there are many articles that address the way it works and in how it heats matter. However, it appears that articles contradict each other in their claims that the heating of the matter is either from the inside or from the outside. What actually means »heating the material in the oven from the inside or from the outside«. In this experiment the heating substance mostly used is water, because most food contains a high percentage of water it is probably the most heated element. The aim is to study how the material is heated, homogeneously throughout the whole volume or unevenly. If the heating is found to be uneven, which parts are more heated, which are less and why is that so. The first part of this paper defines the problem and the hypothesis. The first hypothesis is that the substance in the microwave heats unevenly. The second hypothesis is that law of absorption of electro magnetic waves also applies for the absorption of microwaves generated in the microwave. For a reader's convenience the second part of the research is designed to explain the nature of electromagnetic waves in general and micro waves in particular. The third section describes how microwave oven's work. The fourth part is the basic theoretical explanation for the absorption of electromagnetic waves and the relationship to the heating of the matter. The fifth part describes the research into different cases of heating materials in the microwave oven and looks at a special case which shows that the law of absorption of electro-magnetic waves is valid. The final part summarises the findings and gives us an insight, gained from the study. The appendix contains tables with results of actual measurements which are displayed in graphs.
Keywords (ePrints, secondary language):	microwaves
ID:	8310342