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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.
11

Accuracy of hay moisture sensing systems for round alfalfa bales

Schwindt, Jacob 30 January 2019 (has links)
Master of Science / Department of Biological & Agricultural Engineering / Ajay Sharda / Moisture measurement is critical when baling alfalfa into round bales for feed. If alfalfa is too wet or too dry, it can greatly diminish the alfalfa crop’s feed quality and cause economic loss to producers. Therefore, monitoring of alfalfa moisture content while baling is critical for producers to maintain hay quality and maximize profits. Currently, there are several different types of moisture sensing technologies available for round balers. But, concerns exist regarding their accuracy and repeatability during hay baling. Therefore, objectives of this project are to 1) Establish a protocol for coring methodology to assess the variation of moisture within a round alfalfa hay bale, and 2) Compare and contrast sensing accuracy and repeatability of different hay moisture sensing technologies. A coring methodology was established to determine the average moisture within a round bale based upon the way a sensor in a round baler chamber would determine the bale moisture; by looking at the moisture contents along the round bale diameter. This method was then compared with the more traditional method of using radial cores only to determine the whole bale moisture content. A sensor testing stand was developed to perform comparative testing between the sensors on the same alfalfa hay bale and collect core samples of material immediately after it was formed. Six commercially available moisture sensors were selected to measure moisture at four pre-determined locations on hay bales. After the sensor measurements, core samples were extracted from the exact same locations to determine actual moisture using oven-drying method. The moisture measurements were conducted during three growth stages and bales were formed with three approximate moisture contents of 10%, 15% and 20%. Six different cuts of alfalfa of the same variety were used to capture all the measurements. A seventh cut was also performed for moisture measurements with the alfalfa baled at 15% and the same growth stage, but different baler compression cylinder pressures (250, 400, and 800psi). Actual moisture content was across different sampling locations were compared to understand moisture distribution and establish coring protocol. Sensor and oven-dried measurements were compared to determine accuracy and repeatability of sensing technologies. Results showed that sensors and oven-dried measurement varied for all the sensors for every growth stage and baling moisture levels, with one sensor exhibiting lowest variability in its readings. The comparison identified the most accurate and reliable sensor among the ones currently available. A second year of testing was also conducted to validate the research from the first year of testing. Future research needs to be conducted to identify correlation between the testing stand readings and actual hay baler moisture sensor readings.
12

Immersion frying of potato products

Afaneh, Ibrahim Abdullah January 2001 (has links)
No description available.
13

Energy Dissipation Properties of Cementitious Materials: Applications in Mechanical Damping and Characterization of Permeability and Moisture State

Leung, Chin 2012 August 1900 (has links)
The study of mechanical energy and electrical energy dissipation in cementitious materials can lead to development of high damping concrete for structural applications, and new non-destructive testing techniques for use on existing concrete structures. This research aims to improve mechanical damping properties of cementitious materials and determine durability parameters from complex permittivity measurements. Damping was improved by utilizing poromechanical effects, and by adding viscoelastic and nanometric inclusions. Poromechanics was utilized to model and predict damping on specimens designed to maximize poromechanical effects, and composite theory was used to predict composite bounds for the loss tangent, i.e. modeling the effects on damping due to the addition of viscoelastic inclusions. Experimental results indicated that substantial damping improvement can be realized by both poromechanical effects and adding novel inclusions into cement pastes. The models were able to predict experimentally measured damping as a function of loading frequency. The electrical energy dissipation in cementitious materials was studied by dielectric spectroscopy as a function of moisture state and pore structure/permeability. The results were compared to predictions from multiphase composite modeling, where the properties of the confined water was inversely determined and used to predict moisture content. It was found that moisture state of cementitious materials has a linear relation to the complex permittivity over a wide variety of frequency ranges. Composite model prediction indicated that permeability of saturated cementitious materials studied in this research is likely dependent on the amount of free water in the pores. Permeability can be inferred from the pore structure of the cement paste via complex permittivity measurements by conditioning cement paste at different levels of relative humidity.
14

Influência da umidade nas propriedades de resistência e rigidez da madeira / Influence of moisture content on strength and stiffness of wood

Norman Barros Logsdon 16 December 1998 (has links)
A norma brasileira para o projeto de estruturas de madeira foi alterada, recentemente, abandonando o método determinista das Tensões Admissíveis e adotando o método probabilista dos Estados Limites. Seguindo tendência mundial, a atual norma brasileira, estabelece um teor de umidade de referência de 12%, no qual devem ser reportados os resultados dos ensaios. Dificilmente se conseguirá condicionar, a madeira para o ensaio, com um teor de umidade de exatamente 12%, portanto, será necessário corrigir os resultados do ensaio para este teor de umidade. A atual norma brasileira propõe expressões, para fazer esta correção nas propriedades de resistência e de rigidez da madeira, baseando-se em poucos resultados de ensaios. O objetivo deste trabalho é aferir as expressões propostas pela norma brasileira, sugerindo as alterações necessárias. Uma proposta para a correção da densidade aparente, não prevista na norma brasileira, também será estudada. Para garantir uma base experimental adequada, estuda-se a influência do teor de umidade sobre as propriedades de resistência à compressão paralela às fibras, tração paralela às fibras, cisalhamento paralelo às fibras (no plano radial-longitudinal), bem como sobre o módulo de elasticidade longitudinal e a densidade aparente, em sete diferentes espécies de madeira, correspondentes às sete classes de resistência adotadas pela atual norma brasileira. Conclui-se o trabalho apresentando uma proposta para correção das propriedades de resistência e rigidez ao teor de umidade de 12%. Apresenta-se também uma proposta para a correção da densidade aparente. / The Brazilian Code, NBR 7190/97 - Design of timber structures, was revisited, recently, abandoning the Allowable Stress Method and adopting the States Limits Design Method. Following world tendency, the current Brazilian Code, establishes a reference moisture content of 12%, in which the test\'s results should be registered. It is not possible to keep the specimen, for testing, with exactly 12% moisture content, therefore, it will be necessary to correct the results for this moisture content level. The current Brazilian Code proposes expressions, to do this correction in the strength and stiffness properties of wood, based on few test\'s results. The objective of this work is to judge the expressions proposed by the Brazilian Code, proposing the necessary alterations. A proposal for the correction of the specific gravity, not presented in the Brazilian Code, it will also be studied. To this purpose, the influence of moisture content on the strength in compression and tension parallel to grain, shear parallel to grain (in the radial-longitudinal plane), as well as on the stiffness (modulus of elasticity) and specific gravity, in seven different wood species, corresponding to the seven Brazilian Code strength classes were studied. The conclusions presents a proposal for correction of the strength, stiffness properties and specific gravity, to the 12% moisture content level.
15

Secagem e armazenamento de sementes de Cordia trichotoma (Vellozo) Arrabida ex Steudel / Drying and storage of Cordia trichotoma (Vellozo) Arrabida ex Steudel

Gusatto, Fabiane Cristina 27 February 2015 (has links)
Made available in DSpace on 2017-07-10T17:40:50Z (GMT). No. of bitstreams: 1 Fabiane_Cristina_Gusatto.pdf: 1540638 bytes, checksum: 92339bde69bcc6295bf067510df94dec (MD5) Previous issue date: 2015-02-27 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The forest species Cordia trichotoma (Vellozo) Arrabida ex Steudel, whose seeds are classified as intolerant to desiccation, gives emphasis on the recovery of degraded areas, due to rapid growth and production of high quality wood. The sexual propagation is hindered by the loss of seed viability during the storage period. Thus, the aim of this study was to evaluate the desiccation tolerance and storage of blond-brown seeds with the use of saturated salt solutions of calcium chloride (CaCl2) and calcium nitrate (Ca(NO3)2). The blond-brown seeds were collected in the municipalities of Rondon, Guaíra and Santa Helena in 2012 and immediately transported to the Seed Technology Laboratory and seedlings, State University of West Paraná to perform the processing. Then the seeds were dried in humidity environment controlled with saline solutions, being kept in plastic boxes of higrostat type until they reach the equilibrium moisture content. Before drying, and every 90 days after drying and storage they were determined moisture content, germination percentage, germination speed index, peroxidase activity and respiratory activity. After drying, the seeds were stored in glass bottles and kept in a dry chamber with a temperature ranging from 13 to 17°C for 360 days. The seeds of the town of St. Helena had the largest diameter, germination percentage and germination speed index. Regardless of moisture content, the activities of peroxidase and respiratory enzyme did not affect the physiological potential of seeds. The enzymatic and respiratory activity can be used as indicators of the deterioration of the seeds of this species. The storage conditions of the preserved seed vigor and viability for 6 months / A espécie florestal Cordia trichotoma (Vellozo) Arrabida ex Steudel, cujas sementes são classificadas como intolerantes à dessecação, confere destaque na recuperação de áreas degradadas, devido ao crescimento rápido e produção de madeira de alta qualidade. A propagação sexuada é dificultada pela perda da viabilidade das sementes ao longo do período de armazenamento. Desta forma, o objetivo do trabalho foi avaliar a tolerância à dessecação e armazenamento das sementes de louro-pardo com a utilização de soluções salinas saturadas de Cloreto de cálcio (CaCl2) e Nitrato de cálcio (Ca(NO3)2). As sementes de louro-pardo foram colhidas nos municípios de Marechal Cândido Rondon, Guaíra e Santa Helena no ano de 2012 e imediatamente transportadas ao Laboratório de Tecnologia de Sementes e Mudas da Universidade Estadual do Oeste do Paraná para realização do beneficiamento. Em seguida, as sementes foram secas em ambiente com umidade controlada com as soluções salinas, sendo mantidas em caixas plásticas do tipo higrostat até atingirem o equilíbrio higroscópico. Antes da secagem, e a cada 90 dias após a secagem e armazenamento, foram determinados o grau de umidade, porcentagem de germinação, índice de velocidade de germinação, atividade da enzima peroxidase e a atividade respiratória. Após a secagem, as sementes foram armazenadas em embalagens de vidro e mantidas em câmara seca com temperatura variando de 13 a 17ºC por 360 dias. As sementes da localidade de Santa Helena apresentaram o maior diâmetro, porcentagem de germinação e índice de velocidade de germinação. Independente do grau de umidade, as atividades da enzima peroxidase e respiratória não interferiram no potencial fisiológico das sementes. As atividades enzimática e respiratória podem ser utilizadas como indicadoras da deterioração das sementes desta espécie. As condições de armazenagem das sementes preservaram o vigor e a viabilidade por 6 meses
16

Applicability of crude tall oil for wood protection

Koski, A. (Anna) 05 February 2008 (has links)
Abstract Moisture content control is a very effective way of protecting timber. Treatments with environment-friendly, biodegradable tall oil are known to reduce the capillary water uptake of pine sapwood greatly, but despite the good results achieved there have been two problems that limit the use of tall oil for wood protection, the large amount of oil needed and the tendency for the oil to exude from the wood. This work was undertaken in order to obtain an understanding of the mechanism of wood protection by means of crude tall oil (CTO) and to find technical solutions to the main problems limiting its use for industrial wood protection. It is shown that the emulsion technique is one way of solving the first problem, as it provides high water-repellent efficiency at considerably lower oil retention levels. The fact that water is used as a thinner in this technique instead of the commonly used organic solvents is beneficial from environmental, economic and safety points of view. It is also shown that although the drying properties of CTO are inadequate for use as such in wood preservation, its oxidation and polymerization can be accelerated considerably by means of iron catalysts, which prevent the oil from exuding out of the wood. This also increases the water repellent efficiency of CTO treatment. Most impregnation oils do not dry when applied in large quantities, because they hinder the diffusion of air through the wood, which supplies the necessary oxygen. Limiting of the oil uptake by the means of the emulsion technique disturbs the airflow to a lesser extent, and thus enhances the drying process. Hence, both the emulsion technique and the use of an iron catalyst improve both the water-repellent efficiency of tall oil treatment and the rate of drying of the oil, thus solving the two main problems related to wood impregnation with tall oil in one single-stage treatment which can be used in existing wood preservation plants. This is advantageous from both an industrial and an economic point of view.
17

Prediction Models for Estimation of Soil Moisture Content

Gorthi, Swathi 01 December 2011 (has links)
This thesis introduces the implementation of different supervised learning techniques for producing accurate estimates of soil moisture content using empirical information, including meteorological and remotely sensed data. The models thus developed can be extended to be used by the personal remote sensing systems developed in the Center for Self-Organizing Intelligent Systems (CSOIS). The dfferent models employed extend over a wide range of machine-learning techniques starting from basic linear regression models through models based on Bayesian framework. Also, ensembling methods such as bagging and boosting are implemented on all models for considerable improvements in accuracy. The main research objective is to understand, compare, and analyze the mathematical backgrounds underlying and results obtained from dfferent models and the respective improvisation techniques employed.
18

Evaluation of NO₂ sorption of Japanese cedar wood (Cryptomeria japonica) / スギ材の二酸化窒素収着評価

Nakagawa, Miyuki 24 September 2021 (has links)
京都大学 / 新制・課程博士 / 博士(農学) / 甲第23525号 / 農博第2472号 / 新制||農||1087(附属図書館) / 学位論文||R3||N5356(農学部図書室) / 京都大学大学院農学研究科森林科学専攻 / (主査)教授 梅村 研二, 教授 矢野 浩之, 教授 仲村 匡司 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DFAM
19

Dewatering of Coal Mine Tailings Using Electrokinetics

Sekwele, Matome Ludwick 14 November 2006 (has links)
Student Number : 0418764K - MSc (Eng) dissertation - School of Civil and Environmental Engineering - Faculty of Engineering and the Built Environment / Increasing quantities of finer wastes often contain reactive sulphide minerals and high water contents that pose stability and environmental concerns. This study investigates how electrokinetic process can be improved, to make it more viable towards dewatering finer coal slurries. In the electrokinetic process, a direct current induces the movement of water out of a porous material. A wooden test box was filled up to two-thirds with fine coal slurries. Electrokinetic Geotextiles (EKGs) and brass were used as electrodes. The conducting wires were attached to each electrode and connected to a DC source to form an electro-osmosis cell. Current was passed through the cell and water moved to the cathode where it was withdrawn. The dewatering efficiencies ranged from 13.13 to 109.84 ml/Ah. The energy consumptions ranged from 5.23 to 14.03 kWh/m3 and are in line with those recorded by Johns (2005). Conductivity and pH measurements were taken. EKGs performed better than brass electrodes.
20

Bayesian network development for depots location selection with biomass supply system excellence

Abulhamail, Alaa Ashraf 09 August 2022 (has links) (PDF)
The renewable energy of the wood pellet market has taken great attention over the last few periods. However, the returns from the pellet business depend largely on how well the quality of biomass. The objective is to economically harvest pellets matching pellet standards set forward by the U.S. markets. The single-mindedness of this study is to develop a Bayesian network model to ensure a high-quality flow through the supply chain of the pallet industry in the top ten counties in Mississippi state. Multiple critical decisions (harvesting, storage, transportation, and quality control) of a biomass-to-pellet supply system could potentially affect the supply chain. The biomass-to pellet supply chain is an extremely challenging problem. For Multi-criteria Decision Making,we have developed criteria and sub-criteria associated with biomass-to pellet supply chain pellet. Experimental results specify that the biomass-to-pellet stream system is complex to the biomass quality parameters especially ash and moisture contents. Fifty were studied and ten locations were recommended and ranked based on affordability and resiliency of the availability of both corn stover and forest residues in the depot facilities. There are several anticipated and unpredicted energy turbulence in the Depots property. Pellets have been recognized as an alternative power approach to managing risk throughout power generation. These prospective users from using alternative power. This research proposes a solid foundation for in-depth future research to acquire detailed insights into how the Pellets depots location works in practice in Mississippi state to give a more substantial basis for strategic, tactical, and operational levels of possible risk profiles in Mississippi state.

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