• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 184
  • 9
  • 1
  • 1
  • Tagged with
  • 201
  • 201
  • 129
  • 123
  • 120
  • 118
  • 117
  • 116
  • 116
  • 116
  • 73
  • 73
  • 56
  • 42
  • 39
  • 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

Biogas production at high ammonia levels : The importance of temperature and trace element supplementation on microbial communities

Isaksson, Simon January 2018 (has links)
No description available.
12

A generalized quantum chemical approach for nano- and bio-electronics

Jiang, Jun January 2005 (has links)
A generalized quantum chemical approach for electron transport in molecular devices is developed. It allows to treat the devices where the metal electrodes and the molecule are either chemically or physically bonded on equal footing. Effects of molecular length and hydrogen bonding on the current-voltage (I-V) characteristics of molecular devices are discussed. An extension to include the vibration motions of the molecule has been derived and implemented. It provides the inelastic electron tunneling spectroscopy (IETS) of molecular devices with unprecedented accuracy, and reveals important information about the molecular structures that are not accessible in the experiment. The IETS is shown to be a powerful characterization tool for molecular devices. An effective elongation method has been developed to study the electron transport in nanoand bio-electronic devices at hybrid density functional theory level. It enables to study electronic structures and transportation properties of a 40 nm long self-assembled conjugated polymer junction, a 21 nm long single-walled carbon nanotubes (SWCNT), and a 60 basepairs DNA molecule. It is the first time that systems consisting of more than 10,000 electrons have been described at such a sophisticated level. The calculations have shown that the electron transport in sub-22 nm long SWCNT and short DNA molecules is dominated by the coherent scattering through the delocalized unoccupied states. The derived length dependence of coherent electron transport in these nanostructured systems will be useful for the future experiments. Moreover, some unexpected behaviors of these devices have been discovered. / QC 20101203
13

Transfer Printing and Cellulose Based substrates for modern Textile Printing

Mrad, Mona January 2019 (has links)
Digital printing technology is a technique that has been growing since the 1990s and has a high growth potential when it comes to using different ink types and transfer printing techniques. In comparison to screen printing, digital transfer printing techniques have shown to consume less ink and water and are therefore considered to be a more environmentally friendly alternative for textile printing. Therefore, a digital printing technique called sublimation transfer printing was studied in this thesis. In a sublimation transfer printing process, an image is printed on a paper and then the image is transferred to a textile by using heat and pressure. Suitable coating of the paper surface has shown to improve the printing properties on the paper and therefore the paper samples used in the thesis were coated with three different coating formulas. The coating formulas used in this thesis were polyvinyl alcohol (PVOH) of a type A, PVOH A with ground calcium carbonate (GCC) and PVOH type B with GCC. PVOH A has a higher degree of hydrolysis than PVOH B. Results showed that there was no significant difference between optical densities between textiles and paper samples of different coat weights and coating formulas. The colour bleeding and colour penetration decreased in the printed paper samples for PVOH A + GCC and PVOH B + GCC when the coat weight increased, and the porosity of the coating decreased to some extent. As a conclusion, paper samples coated with PVOH A + GCC with coat weights above 15 g/m2 showed to give the best properties since the colour bleeding was minimal in those printed coated paper samples.
14

Sluta gnata, hantera din data - Ta fram en kravspecifikation för ett LIMS

Bernedal Nordström, Clara, Bürger, Erik, Engberg, Jonas, Jansson, Ylva, Thorell, Hannes, Vaivade, Aina January 2019 (has links)
Excel is a great tool, however it has its flaws. Files quickly become slow as they increase in size, and Excel has no built-in feature to easily search through several documents for a specific word, phrase or value. This can be resolved through a LIMS, a Laboratory Information Management System, which is a database solution that can be used to store and trace laboratory data and information. Our task was to evaluate what system requirements the company Olink Proteomics AB has for a LIMS. By interviewing several departments at Olink, we gained information about what each group wanted from such a system and condensed it into a needs assessment. The interviews showed that traceability was needed for every single department, as well as having easy features for adding data into the system. We were also tasked by Olink to research which Swedish laws apply to old patient data, as the company wants to reuse the data for R&D. Our conclusions are that if data is made fully anonymous, there are no issues in using it for R&D. However, this can be difficult as many criteria have to be fulfilled in order for the data to become fully anonymous.
15

Frying of potato crisps - an investigation aiming at reduction oil content and acrylamide formation

Tran, Mai Thu Thi. January 2006 (has links)
Reducing oil content, minimizing any carcinogenic acrylamide in the high temperature frying process for potato crisps, and producing good products with considerable crispiness and acceptable color were the objectives of this research. Vacuum frying with pre-treatment of potato crisps was investigated as an effective process for oil content reduction. Pre-drying and subsequent dipping (PSSD) in a sugar solution (‘sugar dipping’) were considered as an advantageous procedure for the treatment of potato crisps before frying in order to reduce oil uptake during frying. Vacuum frying was observed as an excellent process to decrease significantly the acrylamide formation at low temperature frying of potato crisps. In this study, potato crisps were respectively blanched, pre-dried, and dipped in a solution of sugar (23.07 wt %) for two seconds, before vacuum frying at 120oC, 110oC under different vacuum pressures (170mbars, 150mbars, 100mbars and 50mbars in separate experiments). Conventional frying at 180oC was also used as the control to benchmark the reductions in the oil contents and acrylamide formation among various techniques. There was a significant reduction in oil content of the potato crisps observed when the new techniques were applied. The crisps that had been pre-treated and fried with conventional frying have given the result of 30 wt % reduction. The crisps that were fried under vacuum frying achieved greater oil reduction with varying percentages when applying different pretreatments. The lowest oil content was achieved when the potato crisps were fried at 110oC and 150 mbars giving 58 % reduction on the dry basis compared with control samples. There are various advantages of the technique with PSSD as we have discovered: it is simple and can be applied in potato crisp industries in continuous mode in both vacuum and conventional frying systems. The crisps that had been treated with pre-drying and subsequent sugar solution dipping and then fried were crunchier and possibly had better perceived taste to the consumer, due to the small sugar addition. Pre-drying and vacuum frying have all turned out to be excellent techniques to reduce acrylamide formation in potato crisps as we have found in this study. Vacuum frying at 120oC and 150 mbars reduced acrylamide formation by 80 to 85%. The 95% reduction was obtained when the crisps had been pre-dried. Acrylamide was undetectable when crisps were pre-dried and vacuum fried at 110oC, 150 mbars. The crisps with pre-drying subsequent sugar dipping and vacuum fried at low temperature had improved color compared with the control samples, which were produced by conventional frying at high temperatures. / Note: Part 3 publication restricted due to copyright restrictions.
16

Frying of potato crisps - an investigation aiming at reduction oil content and acrylamide formation

Tran, Mai Thu Thi. January 2006 (has links)
Reducing oil content, minimizing any carcinogenic acrylamide in the high temperature frying process for potato crisps, and producing good products with considerable crispiness and acceptable color were the objectives of this research. Vacuum frying with pre-treatment of potato crisps was investigated as an effective process for oil content reduction. Pre-drying and subsequent dipping (PSSD) in a sugar solution (‘sugar dipping’) were considered as an advantageous procedure for the treatment of potato crisps before frying in order to reduce oil uptake during frying. Vacuum frying was observed as an excellent process to decrease significantly the acrylamide formation at low temperature frying of potato crisps. In this study, potato crisps were respectively blanched, pre-dried, and dipped in a solution of sugar (23.07 wt %) for two seconds, before vacuum frying at 120oC, 110oC under different vacuum pressures (170mbars, 150mbars, 100mbars and 50mbars in separate experiments). Conventional frying at 180oC was also used as the control to benchmark the reductions in the oil contents and acrylamide formation among various techniques. There was a significant reduction in oil content of the potato crisps observed when the new techniques were applied. The crisps that had been pre-treated and fried with conventional frying have given the result of 30 wt % reduction. The crisps that were fried under vacuum frying achieved greater oil reduction with varying percentages when applying different pretreatments. The lowest oil content was achieved when the potato crisps were fried at 110oC and 150 mbars giving 58 % reduction on the dry basis compared with control samples. There are various advantages of the technique with PSSD as we have discovered: it is simple and can be applied in potato crisp industries in continuous mode in both vacuum and conventional frying systems. The crisps that had been treated with pre-drying and subsequent sugar solution dipping and then fried were crunchier and possibly had better perceived taste to the consumer, due to the small sugar addition. Pre-drying and vacuum frying have all turned out to be excellent techniques to reduce acrylamide formation in potato crisps as we have found in this study. Vacuum frying at 120oC and 150 mbars reduced acrylamide formation by 80 to 85%. The 95% reduction was obtained when the crisps had been pre-dried. Acrylamide was undetectable when crisps were pre-dried and vacuum fried at 110oC, 150 mbars. The crisps with pre-drying subsequent sugar dipping and vacuum fried at low temperature had improved color compared with the control samples, which were produced by conventional frying at high temperatures. / Note: Part 3 publication restricted due to copyright restrictions.
17

Frying of potato crisps - an investigation aiming at reduction oil content and acrylamide formation

Tran, Mai Thu Thi. January 2006 (has links)
Reducing oil content, minimizing any carcinogenic acrylamide in the high temperature frying process for potato crisps, and producing good products with considerable crispiness and acceptable color were the objectives of this research. Vacuum frying with pre-treatment of potato crisps was investigated as an effective process for oil content reduction. Pre-drying and subsequent dipping (PSSD) in a sugar solution (‘sugar dipping’) were considered as an advantageous procedure for the treatment of potato crisps before frying in order to reduce oil uptake during frying. Vacuum frying was observed as an excellent process to decrease significantly the acrylamide formation at low temperature frying of potato crisps. In this study, potato crisps were respectively blanched, pre-dried, and dipped in a solution of sugar (23.07 wt %) for two seconds, before vacuum frying at 120oC, 110oC under different vacuum pressures (170mbars, 150mbars, 100mbars and 50mbars in separate experiments). Conventional frying at 180oC was also used as the control to benchmark the reductions in the oil contents and acrylamide formation among various techniques. There was a significant reduction in oil content of the potato crisps observed when the new techniques were applied. The crisps that had been pre-treated and fried with conventional frying have given the result of 30 wt % reduction. The crisps that were fried under vacuum frying achieved greater oil reduction with varying percentages when applying different pretreatments. The lowest oil content was achieved when the potato crisps were fried at 110oC and 150 mbars giving 58 % reduction on the dry basis compared with control samples. There are various advantages of the technique with PSSD as we have discovered: it is simple and can be applied in potato crisp industries in continuous mode in both vacuum and conventional frying systems. The crisps that had been treated with pre-drying and subsequent sugar solution dipping and then fried were crunchier and possibly had better perceived taste to the consumer, due to the small sugar addition. Pre-drying and vacuum frying have all turned out to be excellent techniques to reduce acrylamide formation in potato crisps as we have found in this study. Vacuum frying at 120oC and 150 mbars reduced acrylamide formation by 80 to 85%. The 95% reduction was obtained when the crisps had been pre-dried. Acrylamide was undetectable when crisps were pre-dried and vacuum fried at 110oC, 150 mbars. The crisps with pre-drying subsequent sugar dipping and vacuum fried at low temperature had improved color compared with the control samples, which were produced by conventional frying at high temperatures. / Note: Part 3 publication restricted due to copyright restrictions.
18

Frying of potato crisps - an investigation aiming at reduction oil content and acrylamide formation

Tran, Mai Thu Thi. January 2006 (has links)
Reducing oil content, minimizing any carcinogenic acrylamide in the high temperature frying process for potato crisps, and producing good products with considerable crispiness and acceptable color were the objectives of this research. Vacuum frying with pre-treatment of potato crisps was investigated as an effective process for oil content reduction. Pre-drying and subsequent dipping (PSSD) in a sugar solution (‘sugar dipping’) were considered as an advantageous procedure for the treatment of potato crisps before frying in order to reduce oil uptake during frying. Vacuum frying was observed as an excellent process to decrease significantly the acrylamide formation at low temperature frying of potato crisps. In this study, potato crisps were respectively blanched, pre-dried, and dipped in a solution of sugar (23.07 wt %) for two seconds, before vacuum frying at 120oC, 110oC under different vacuum pressures (170mbars, 150mbars, 100mbars and 50mbars in separate experiments). Conventional frying at 180oC was also used as the control to benchmark the reductions in the oil contents and acrylamide formation among various techniques. There was a significant reduction in oil content of the potato crisps observed when the new techniques were applied. The crisps that had been pre-treated and fried with conventional frying have given the result of 30 wt % reduction. The crisps that were fried under vacuum frying achieved greater oil reduction with varying percentages when applying different pretreatments. The lowest oil content was achieved when the potato crisps were fried at 110oC and 150 mbars giving 58 % reduction on the dry basis compared with control samples. There are various advantages of the technique with PSSD as we have discovered: it is simple and can be applied in potato crisp industries in continuous mode in both vacuum and conventional frying systems. The crisps that had been treated with pre-drying and subsequent sugar solution dipping and then fried were crunchier and possibly had better perceived taste to the consumer, due to the small sugar addition. Pre-drying and vacuum frying have all turned out to be excellent techniques to reduce acrylamide formation in potato crisps as we have found in this study. Vacuum frying at 120oC and 150 mbars reduced acrylamide formation by 80 to 85%. The 95% reduction was obtained when the crisps had been pre-dried. Acrylamide was undetectable when crisps were pre-dried and vacuum fried at 110oC, 150 mbars. The crisps with pre-drying subsequent sugar dipping and vacuum fried at low temperature had improved color compared with the control samples, which were produced by conventional frying at high temperatures. / Note: Part 3 publication restricted due to copyright restrictions.
19

Biogas upgrading by Scenedesmus grown in diluted digestate

Farinacci, Julie January 2018 (has links)
The aim of the work was to examine microalgae growth and nutrient elimination in various diluted digestates in the first trial, then to study CO2 removal from a simulated biogas mixture by the same strain in the second trial. Scenedesmus SCCP K-1826 was cultivated in the digestate from Sundet biogas plant diluted 10, 20 and 30 times. The cultures were open-air with occasional CO2 injections to control pH. On day 15, the best growth was obtained in the 10 times diluted sample. COD, TN and TP removal efficiencies were similar in each bottle as the strain didn’t perform better in any specific dilution. The control proved that additional mechanisms other than photosynthesis contributed to digestate cleaning. Using the 10 times diluted sludge, Scenedesmus was grown in sealed flasks filled with simulated biogas (35.3 % CO2 + 32.3 % CH4 + 32.3 % N2). More algal biomass was produced in this batch culture. Nutrient removal efficiencies were close to the ones reached in the open-air flasks. After 10 days, 96 % of carbon dioxide was reduced. Methane content was depleted as well, possibly due to undesirable methane oxidizing bacteria which infiltrated the medium.
20

Rural Organic Waste Treatment System Design and Analysis-Based on Vermicomposting Technology

Li, Xiangyu January 2011 (has links)
Rural organic waste is becoming a problem in developing countries due to lack of financial and technological support comparing with situation in urban area. A rural organic waste treatment system was designed utilizing vermicomposting technology to treat organic waste generated in rural area. ROWATS is a theoretical facility to treat rural organic wastes in Shandong Peninsula, China where cow dung and domestic organic waste are disposed freely. Theoretical demonstration shows that ROWATS can treat 1,200 kg of organic wastes daily and produce around 20 tons of vermicast and 800 kg of earthworm body and larvae every month. Products of ROWATS can be used as soil fertilizer, fish bait, and biopharmaceuticals and so on. Sufficient financial support is the most important factor for ROWATS in rural area. Cost-Benefit Analysis and Net Present Value Calculation were made to assess the feasibility of ROWATS. Results showed that ROWATS is a profitable project in terms of 2 years and 5 years. Sensitivity Analysis is also applied to evaluate the impact of different factors variation on ROWATS, of which result shows price and productivity variation of products can affect the profit of ROWATS more significantly comparing with cost changes. Hence, operator should keep products production stable. ROWATS can also improve the environmental and hygienic impacts through reduction of leakages, odor and bacteria and virus infection from flies, mosquitoes and other poisonous species.

Page generated in 0.1074 seconds