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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.
1

Emissions of isoprene and monoterpenes from native Mediterranean vegetation

Owen, Susan Margaret January 1998 (has links)
No description available.
2

Performance Study on the treatment of VOC Containg Gases from Paint Blending Processes

Huang, Hao-lun 09 September 2004 (has links)
In response to growing concern over volatile organic compounds (VOCs) biofiltration is becoming an established economical air pollution control technology for removing VOCs from waste air stream. This study armed to develop a trickle-bed biofilter to treat emitted VOCs stream from a piant blending process. Analytical results demonstrated that the VOCs conceratration range is 10 to 1500 ppm calibrated as methane and the major components of the emitted gases are toluene, xyluene, isobutanol, methyl-isopropyl ether, etc. Originally, a full-scale biotrickling filter of 6m ¡Ñ 6m in inner cross-sectional area packed with wood chips(10 cm ¡Ñ 10 cm ¡Ñ 2 cm) to a height of 4 m was used to treat the vent gas with a flow rate of 270 m3/min. A recycle water rate of 400 L/min and a nutrient liquid (acid digested liquor of bird feather) addition rate of 1L/day. Under these operation parameters, the average VOC removal efficiency of the original trickling filter of 28% which was not as good as expected. To improve the efficiency, a pilot biofilter constructed from a 0.3-m x 1.6-m (OD x H) plastic column packed with fam chips to a height of 1 m was used for treating a sample stream of the vent gas. Empty bed retention times in the range of 9.82 to 20 s, corresponding inlet flow rates of 0.68 to 0.27 m3/min and the organic loading rates of 5.18 to 10.37 g/m3.hr were used. As the empty bad retention times was getting shorter, the removal efficiency become lower (from 80 to 75.56%). When the organic loading rose to 186.65 g/m3.hr, the removal efficient also got down to 24%. As the gas temperature droped to 10OC,the removal efficient also decreased to 43%.
3

Porovnání rosé vín vyrobených z odrůdy Frankovka

Horák, Ondřej January 2015 (has links)
The aim of this thesis was to evaluate the sensory and analytical properties of selected rosé wine varieties Lemberger from the site of VOC Blue Mountains. In this work they were produced samples of rosé wines from different vineyards. Samples were made a single technologies. From the analytical values were determined for wines alcohol content, reducing sugar content, pH, titratable acidity, content of glycerol content of nthocyanins content of flavanols, polyphenols, antiradical value and volatile substances. All samples were evaluated by 100 points system according Balik and Veverka. Top samples were evaluated from vineyards Bojanovska (Velké Pavlovice) Novosady(Němčičky) and Terasy (Bořetice).
4

Olfaktometrické posouzení emitovaných VOC vybraným typem povrchové úpravy použitého při výrobě kuchyňského nábytku

Jeřábek, Martin January 2010 (has links)
No description available.
5

Streamlining the Voice of the Customer : A study exploring Voice of the Customer at Company X

Gawthrop, Jeffrey, Gopal, Srikanth January 2017 (has links)
One of the components of customer focus in a company is voice of the customer (VOC). Companies use the VOC for guiding them in producing products and services that help meet customer needs.  There exists numerous VOC methods from literature for collecting VOC data, and it often recommends using multiple VOC methods to obtain better insight into consumer use, needs and problems.   In addition, the literature recommends companies to have a unified data collection process to effectively collect, integrate and understand the VOC. In this explorative case study, the authors investigate the VOC methods used by Company X and how VOC data collected from various methods are aggregated and employed at Company X.  Company X is a large bus manufacturing company with a global presence and annual revenue of 3.1 billion USD. The study intends to understand if the academic recommendations reflect VOC practices at Company X. The results from the study find that the criterion for choosing VOC methods at Company X is determined by the complexity of methods.  Elaborate methods, such as focus groups and ethnography that help in complementing more commonly used methods, such as interviews and questionnaires, to capture necessary customer information, are not preferred due to being time and resource intensive.   Furthermore the need for a structured process to aggregate VOC data from different sources is felt across the organization at Company X.  However, the high cost of implementing a VOC process, resource constraints and un-evident benefits of a structured VOC process are found to be the main reasons that work against implementation of a structured process.
6

The political economy of skills formation: explaining differences in Central and Eastern Europe / Gebėjimų formavimo politinė ekonomija: skirtumų Rytų ir Vidurio Europos šalyse aiškinimas

Martinaitis, Žilvinas 02 November 2010 (has links)
The dissertation seeks to explain, why different skills formation systems have emerged in Central and Eastern Europe over the past 20 years. More specifically, it investigates, why the labor force acquires general skills in the Baltic States, Poland and Hungary, while specific skills are of utmost importance in the Czech and Slovak Republics and Slovenia? The dissertation argues that these differences can be explained by the labor market, economic and political institutions. Strong employers’ associations, high employment security, generous unemployment benefits, proportional electoral system and government stability are necessary for emergence of specific skills formation systems, while absence of these institutions is sufficient for the emergence of general skills formation systems. The dissertation employs fuzzy set techniques and robust regression to test the hypotheses empirically. / Disertacijoje siekiama paaiškinti, kodėl Vidurio Rytų Europos šalyse išsivystė skirtingos gebėjimų formavimo sistemos, t.y. kodėl Baltijos šalyse ir mažesniu mastu Lenkijoje bei Vengrijoje per pastaruosius 20 metų iškilo bendrųjų gebėjimų formavimo sistemos, o Čekijoje, Slovėnijoje ir Slovakijoje – specifinių gebėjimų formavimo sistemos? Darbe teigiama, kad tai nulėmė skirtingos darbo rinkos, ekonominės ir politinės institucijos. Stiprios darbdavių asociacijos, aukštas darbo vietos apsaugos lygis, dosnios išmokos bedarbiams, proporcinė rinkimų sistema ir Vyriausybių stabilumas yra būtinos sąlygos specifinių gebėjimų formavimo sistemoms atsirasti. Jei vienos ar kelių iš įvardintų institucijų nėra, tuomet atsiranda pakankamos sąlygos bendrųjų gebėjimų formavimo sistemos atsiradimui. Hipotezės tikrinamos remiantis neapibrėžtųjų aibių ir apibrėžtos regresijos (angl. robust regression) metodais.
7

Využití koncepce Six Sigma v odděleních finanční instituce

Šrámková, Dana January 2007 (has links)
Tato diplomová práce pojednává o využití koncepce Six Sigma ve finanční instituci. Konkrétně bylo sledováno využití Six Sigmy na oddělení Správy pohledávek a na Zákazanické lince. V obou případech byly nastavovány procesy příchozích hovorů na tato oddělení. Procesy byly nastavovány pomocí metody DMAIC. Z práce jsou zřejmá zlepšení po implementaci změn. Součástí diplomové práce jsou detailní analýzy příchozích hovorů a defektů při jejich přijímání.
8

Treatment of Styrene and Acrylonitrile in Air Streams by Full-scale Biotrickling Filters

tu, Amy 20 June 2001 (has links)
Abstract This research focuses on the performance of a full-scale biotrickling filter (BTF) for treating a vented gas from an ABS (acrylonitrile-butadiene-styrene) resin plant. The BTF was constructed by reinforced concrete with a size of 5 m in width, 9 m in length, and 3.5 m in height. It consists of six individual chambers with packing materials of 4.6m in length and 4.2m in width for each. The vented gas contains styrene (SM) and acrylonitrile (AN) as two major components and has an average flow rate of 43,000 m3/h (720 m3/min) and a temperature range of 40-53¢J. Three test protocols have been studied to understand the effects of changing scrubbing method, types of packing materials, and amounts of packing materials on the pollutant removal efficacy. Two different instruments (portable FID and laboratory GC) were used to measure the VOC concentrations for both the inlet and outlet of the BTF. Many parameters were monitored for trend analysis, including gas flow rate, empty-bed gas retention time, system temperature, inlet and outlet VOC concentrations, VOC mass flow rate, organic loading, VOC removal efficiency, recirculation water volume, VOC concentration in the recirculation water, and mass flow rate of the recirculation water. These data were analyzed for discussing the technical feasibility of using BTF as an air pollution control unit for petrochemical industry. Experimental results showed that the third protocol using PVC packing materials (installed with 4.6m in length, 4.2 in width, and 0.6m in height for each of the 6 chambers) was the best setup for the target VOC removal. Without adding any special seed and supplementary nutrient, effluent of the wastewater treatment unit of the plant was introduced into the BTF as the recirculation water (pH 7-8.5, volumetric flow rate 15-30 m3/h, and temperature was 35-50¢J). A range of VOC removal efficiencies of 8.6-41% (equivalent to volumetric elimination rates of K = 41-949 g/m3.h) was obtained with loadings of L = 469-3015 g/m3.h based on the GC data. The elimination rates were 41-949 and 27.4-562 g/m3.h, respectively, for AN and SM corresponding to loadings of 121-1104 and 818-1756 g/m3.h for the two components. An average removal efficiency (K/L) of 24.5% was obtained for AN and SM regardless of the magnitude of the loading. Distribution of VOC removal was 13% by biofilms and the rest by the recirculation water. Microbiological tests revealed that Nematods was the most dominating species at high loadings and Trachelophyllum sp. was the most dominating species at lower loadings. It was also estimated that a total operating cost of NT$ 23,920/day is required and that is equivalent to a cost of NT$ 34.1 for eliminating 1 kg of VOCs from the waste gas. The data showed that the VOC loading (469-3015 g/m3.h, average 1808 g/m3.h) to the BTF was much higher than the normal design value of 30-60g/m3.h. It is suggested that a pre-treatment unit should be added into the system to lower the organic loading before the waste stream enters the BTF. In addition, the makeup recirculation water should be increased to foster the bacteria growth and to improve the absorption of VOCs from the waste gas.
9

Performace study on the treatment of gas-borne chlorohydrocarbons by Regenerative Thermal Oxidizer

Hei, Cheng-Ming 11 July 2002 (has links)
In this study, a pilot-scale regenerative thermal oxidizer (RTO) was used to test its performance for volatile organic compound (VOC) destruction and degree of thermal energy recovery. The purposes were to improve its performance and establish its operation conditions. The RTO is electrically heated and contains two 0.5 m ¡Ñ 0.5 m ¡Ñ 2.0 m (L ¡Ñ W ¡Ñ H) beds both packed with gravel particles of around 1.16 cm in average diameter to a height of 1.48 m. The bed has a void fraction of 0.405. Experiments include two phases: (1) tests to find the degree of energy conservation and the pressure drop for the air stream with no VOC in the influent air stream, and (2) tests to find the degree of VOC destruction with influent air streams containing one of the three VOCs: trichloroethylene, dichloromethane, and dibutyl ether. Intermediates in the course of VOC destruction were also detected in the second phase experiment. Phase one experiment was conducted for the following conditions: superficial gas velocity (evaluated at ambient temperatures of 26-29oC) Ug = 10-20 m/min, bed shift time ts = 1.5 min, and maximum gravel temperature Tmax = 474-778oC. Results show that the RTO has a thermal recovery efficiency R of over 85% and Ug is the main affecting factor. R is inversely proportional to Ug. Gas pressure drop over the bed height is proportional to the average temperature of the bed gravels. In the phase two experiments, Ug of 10-20 m/min, ts of 1.5 min, and Tmax of 475-487 and 758-778oC were used. Results show that over 90% of the influent VOCs were destructed when Tmax was set in the higher range. However, in the lower Tmax, over 80% destruction was obtained only for dibutyl ether and the VOC destruction was not closely related to Ug. For Tmax = 475-487oC and Ug = 10-20 m/min, complete oxidation products of trichloroethylene and dichloromethane are HCl, CO2, and H2O, and the main intermediates are CO, COCl2, and C2Cl4 (detected only for trichloroethylene). For dibutyl ether, complete oxidation products are CO2, and H2O, and the main intermediates are CO, alkenes, alcohol, alkenes, and acetic acid. For Tmax = 758-778oC and Ug = 10-14.5 m/min, complete oxidation products of trichloroethylene and dichloromethane are HCl, CO2, and H2O, and the main intermediates are CO and COCl2. No acetic acid was detected for dibutyl ether in the higher temperature range. An operation cost of US$ 3.33/(1,000 m3 waste gas) was estimated with the RTO operated in the higher temperatures and a flowrate of 2.5 m3/min (Ug = 10 m/min).
10

Chemical Scrubbing of fume gas stream from corn germ pressing machine

Huang, Li-Min 15 July 2002 (has links)
Abstract This study armed to develop a chemical scrubbing process to treat an emitted odorous gas stream from a corn-germ oil-pressing machine. Analytical results demonstrated that the gas contains a total VOC (volatile organic compound) concentration of 323 to 2,100 ppm calibrated as methane. Major VOC ingredients are aldehydes, organic acids, and mercaptans. Ozone, sodium hypochlorite (NaOCl), and hydrogen peroxide (H2O2) were used as oxidants for VOCs other than aldehydes and sodium bisulfite (NaHSO3) was used as a reductant for aldehydes. Experimental setup used in this study consisted of a set of four-stage-in-series scrubbers for VOC oxidation and a set of 18-L bubble column for aldehyde reduction. Each stage of the scrubber was constructed from a 25-cm x 140-cm (OD x H) plastic column packed with 2¡¨-diameter plastic packings to a height of 90 cm. Experiment results showed that suitable conditions for the VOC and odor removal in the oxidation tower are: (1) QL/QG (flowrate ratio of circulating liquid and gas) = 0.0024-0.0035 m3 liquid/m3 gas, (2) dose rate of NaOCl solution (10 % effective chlorine) = 0.0125-0.015 L/m3 gas, (3) pH of the circulating liquid = 7.5-8.0, and (4) supplemental water flowrate = 2.4-5.0 L/m3 gas. Those for the reduction of the residual aldehydes and other odorous compounds are: (1) concentration of NaHSO3 scrubbering solution = 2,156 mg/L as SO2 and (2) pH of the NaHSO3 solution = 5.0-6.0. Under the conditions, experimental data demonstrated that the process could reduce H2S from 0-5.5 to 0 ppm, NH3 from 0.1-0.4 to 0-0.1 ppm, phenols from 0-2.0 to 0 ppm, acids from 15-25 to 0 ppm, acetaldehyde from 10-34 to 0-10 ppm, amines from 0.1 to 0.1 ppm, and mercaptans from 0.5-10.5 ppm to 0 ppm. Overall VOC removal efficacy was 85-100 %. Effluent gas from the oxidation stage had a chlorine smell, while that from the reduction one was odorless. Based on the results from the pilot study, a full-scale plant with a waste gas flow rate 105 m3/min was proposed. It was estimated that the full-scale plant has an equipment cost of US$ 45,000, and an operating cost of around US$ 110/(8-hr day) or US$ 0.75/(1,000 m3 waste gas).

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