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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.
21

Home Storage of Vegetables

Tate, Harvey F. 10 1900 (has links)
This item was digitized as part of the Million Books Project led by Carnegie Mellon University and supported by grants from the National Science Foundation (NSF). Cornell University coordinated the participation of land-grant and agricultural libraries in providing historical agricultural information for the digitization project; the University of Arizona Libraries, the College of Agriculture and Life Sciences, and the Office of Arid Lands Studies collaborated in the selection and provision of material for the digitization project.
22

Equilibrium moisture content of beans

Guevara Guio, Melquiades January 2010 (has links)
Digitized by Kansas Correctional Industries
23

Moisture adsorption of bulk stored grain under tropical conditions

Caro Greiffenstein, Axel January 2010 (has links)
Digitized by Kansas Correctional Industries
24

Some changes during storage in McIntosh, Cortland and Wealthy varieties of apples.

LeBrec, Robert Leon 01 January 1947 (has links)
No description available.
25

Processing treatments to extend the storage time of frozen pink salmon

Mathers, John Hamilton 08 May 1950 (has links)
Graduation date: 1950
26

Investigation of a low heat loss high temperature thermal energy storage system

Cope, Norman Alan, January 1982 (has links)
Thesis (Ph. D.)--University of Florida, 1982. / Description based on print version record. Typescript. Vita. Includes bibliographical references (leaves 140-143).
27

Thermal energy storage by agitated capsules of phase change material

Sözen, Zeki Ziya January 1985 (has links)
Thermal energy storage via the latent heat of suitable phase change materials has the advantages of higher energy storage density and relatively isothermal behaviour compared to sensible heat storage systems. Glauber's salt (Na₂S0₄∙10H₂0) is one of the most extensively studied phase change materials for solar energy systems because of its low price, suitable phase change temperature and high latent heat. However, segregation due to incongruent melting behaviour leading to loss in the heat storage efficiency upon repeated melting-freezing cycling is a serious problem which has severely limited application of Glauber's salt. In this study Glauber's salt was encapsulated in 25 mm diameter hollow spheres and agitated in different systems including a liquid fluidized bed, rotating drum and rotating tube to reduce or eliminate the Toss in its heat storage efficiency. The encapsulated mixture consisted of 96% Glauber's salt and 4% borax by weight with 5% by volume air space in the capsules. Some capsules containing 25%, 15% and 5% by weight excess sodium sulfate and 10% by weight excess water were also prepared, to test the effect of sodium sulfate concentration under different agitation conditions. The heat storage capacity of 5756 capsules, agitated by fluidizing with water in a pilot plant size (0.34 m diameter) column, showed a decrease over the first three cycles to about 60% of that theoretically possible, but there was no further decrease over the next 93 cycles under fluidization conditions. The heat storage efficiency was found to be improved by increasing the superficial water velocity and by decreasing the cooling rate. Heating rate had little or no effect. The fluidized capsules provide enhanced heat transfer rates to or from the heat storage medium, enabling the energy to be charged or discharged in about one hour with realistic inlet and outlet temperatures. The high heat transfer rates are an important advantage for the system and may open new areas of applications for thermal energy storage by encapsulated phase change material. Economic analysis of the liquid fluidized bed heat storage system shows that operating costs are almost negligible compared to fixed capital costs. The heat storage efficiency of capsules decreased to 38.4% of the theoretical capacity or 67% of the corresponding agitated (fluidized) system in only 7 cycles under fixed bed conditions, and the efficiency decreased with further cycling. 97.5% of the original heat storage-capacity was recovered within three cycles when these capsules were refluidized. Performances of the regular and different composition capsules were tested in the rotating tube, with rotation around a fixed horizontal axis passing through the capsules' centers, and in the rotating drum, with impact due to collisions in addition to rotation. The results showed that full rotation of a capsule around a horizontal axis improves the heat storage efficiency. However, full recovery of the theoretical capacity was not possible, even under vigorous mixing conditions. The efficiencies in the rotating tube were similar to those in the rotating drum for capsules subject to the same number of rotations around a horizontal axis. At high rotation speeds centrifugal force had a negative influence, especially in the rotating tube. On the basis of heat storage capacity per unit volume or weight of phase change material, 47% by weight sodium sulfate concentration was found to be optimal for the rotating drum and the rotating tube cases. Some small scale experiments were performed to determine the relative importance of different factors in the loss of heat storage capacity. Sodium sulfate concentration gradients in the capsules with different thermal cycling histories were found by thermogravimetric analysis. The results showed that bulk segregation of anhydrous sodium sulfate is not the only reason for the loss of heat storage capacity in systems using Glauber's salt. Microencapsulation of anhydrous sodium sulfate beneath a layer of Glauber's salt crystals is at least as important. Experiments to determine the degree of subcooling, believed to be another factor in the loss of heat storage capacity, showed that a mixture of 96% Glauber's salt and 4% borax by weight undergoes subcooling of about 5 K in gently agitated capsules. Nucleation and crystallization temperatures both increase with increased agitation. / Applied Science, Faculty of / Chemical and Biological Engineering, Department of / Graduate
28

Logic-per-track associative memory

Tang, Geok-Seng January 1976 (has links)
An associative, or content-addressable, memory, one in which data may he retrieved "by its value rather than by real address, has always been an attractive idea. Although such a memory has not yet proven practical for files of respectable size, much interesting work has been done on the subject, for example, Minsky (1972), Slotnick (1970) and Parker (1970, 1971). This thesis is concerned with the device proposed by Slotnick and Parker, called 'Logic Per Track Device'. After briefly reviewing the design and capabilities of their device, the thesis proceeds to propose some modifications to the design which not only lead to greatly enhanced performance, but also establish its practical application for files of respectable size. In the device of Slotnick and Parker, there is a fairly sophisticated logic chip attached directly to each non-movable read-write head. This allows all logic heads to search simultaneously for information matching a given key, so that any desired record could be located within one revolution. However, reading and writing will require a second revolution because part of the record will have passed the head before the match is recognized. Moreover, if more than one record matches the search key, the extra bookkeeping will be needed if matching records on different tracks should partially overlap. These problems have been ignored in the retrieval system developed by Parker (1970, 1971). The following four additional features of the device have been proposed: 1. Two logic heads on each track has been introduced. The leading head will continue to have the primary responsibility for simultaneous searching. The additional second head, trailing a fixed distance behind will do the actual reading and writing of records. 2. A delay register whose length is the distance between logic heads on the same track, has been added to the read-write head. The function of the delay bit is to tell the read-write head partner where to start reading (or writing) a record whenever a match is recognized so that retrieving (or writing) a single record can always be performed in the same revolution. 3. Another major design change will give the new device the ability to keep track of all records which may be retrieved within a single revolution by parallel search. To this end, the monitor, which synchronizes the activities of all logic head couples, will be provided with a record counter, and a mark entity will be prefixed to every record on the disk itself. A file identification mechanism has been established for the associative memory. Functions of such a mechanism are (a) to manage file names, and (b) to manipulate data on the storage device. Next step is to explore the use of such a modified device for file-oriented problems. 'Hierarchical search' for records possessing a specified combination of keys can be performed directly on the key part of records without the intermediate step of transmitting records into the main computer memory. In an application requiring chain processing, the chain pointer can he a key of the record because each record in the associative memory is accessed by content rather than by real address. The chain key can be generated from the key if the record it points to by a simple and reversible procedure. Such a chain technique has a number of advantages: (a) any chain is in fact a two-way chain, (b) each record in the chain can be retrieved by following the chain key, or directly by the key of the record if it is known, and (c) the tangle of actual physical addresses in the chain processing can be avoided. The storage organization for more complex data structure such as tree structures presents another unique feature of the modified memory. In a tree structure, indexes to the subordinate records may be kept with each parent record, or each subordiante recoEdsnjaays^tDreaaniaindsx to its parent record. Both data structures take the same amount of storage space. Comparison <3f its performance to the convent tional counterpart shows that significant improvements in access times can be achived. / Science, Faculty of / Computer Science, Department of / Graduate
29

Dispatch of Bulk Energy Storage in Power Systems with Wind Generation

January 2012 (has links)
abstract: This thesis concerns the impact of energy storage on the power system. The rapidly increasing integration of renewable energy source into the grid is driving greater attention towards electrical energy storage systems which can serve many applications like economically meeting peak loads, providing spinning reserve. Economic dispatch is performed with bulk energy storage with wind energy penetration in power systems allocating the generation levels to the units in the mix, so that the system load is served and most economically. The results obtained in previous research to solve for economic dispatch uses a linear cost function for a Direct Current Optimal Power Flow (DCOPF). This thesis uses quadratic cost function for a DCOPF implementing quadratic programming (QP) to minimize the function. A Matlab program was created to simulate different test systems including an equivalent section of the WECC system, namely for Arizo-na, summer peak 2009. A mathematical formulation of a strategy of when to charge or discharge the storage is incorporated in the algorithm. In this thesis various test cases are shown in a small three bus test bed and also for the state of Arizona test bed. The main conclusions drawn from the two test beds is that the use of energy storage minimizes the generation dispatch cost of the system and benefits the power sys-tem by serving the peak partially from stored energy. It is also found that use of energy storage systems may alleviate the loading on transmission lines which can defer the upgrade and expansion of the transmission system. / Dissertation/Thesis / M.S. Electrical Engineering 2012
30

Prestorage treatment of grapefruit with 2,4-D and its effect on metabolism of fruits in storage

Mahmoud, Salah Eldin Mohamed January 1953 (has links)
No description available.

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