• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 32
  • 28
  • 9
  • 7
  • 5
  • 4
  • 3
  • 3
  • 1
  • 1
  • Tagged with
  • 96
  • 31
  • 31
  • 31
  • 20
  • 19
  • 18
  • 18
  • 18
  • 16
  • 15
  • 15
  • 14
  • 13
  • 11
  • 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

Digitaliserad word of mouth, en betydande faktor för WTA : En experimentell studie applicerad på valet av mäklare

Ståhl, Andreas, Westblad, Markus January 2019 (has links)
Sammanfattning   Titel: Digitaliserad word of mouth, en betydande faktor för WTA   Nivå: Examensarbete på Grundnivå (kandidatexamen) i ämnet företagsekonomi   Författare: Andreas Ståhl och Markus Westblad   Handledare: Jonas Kågström, Benny Berggren   Datum: 2019 – Juni    Syfte: Syftet med denna studie är att öka förståelsen för hur eWOMs volym och valens påverkar konsumenters WTA i valet av tjänst från säljare. I denna studie har en undersökning av begrepp som WTA och eWOM ställts emot varandra i en experimentell design som sedan genom resultatet delat en förståelse för hur volym och valens påverkar valet av en fastighetsmäklare. Studien har genom tidigare forskning önskats applicerats på andra branscher än tidigare utförda vilket vi anser att denna studie uppfyller genom den replikerade metod som använts.   Metod: Denna studie är utförd genom en kvantitativ forskningsstrategi med en replikerande metod med experimentell design. Den data som samlats in som underlag för studiens resultat och analys har samlats in genom en digital enkät med manipulerade mäklarprofiler genom rekommendationssajten ”Reco”. Datan har sedan analyserats genom programvaran ”Jamovi” genom deskriptiva analyser samt genom en korrelationsanalys.   Resultat & slutsats: Studien har visat resultat som motsäger tidigare forskning med bland annat att volym är mer avgörande i valet av en tjänst i relation till valens.   Detta resultat visar även på att fler bör studera sina branscher för att öka sin förståelse för hur kraftigt vissa faktorer är inom digitaliserad marknadsföring.   Examensarbetets bidrag: Studien presenterar ett teoretiskt såväl som praktiskt bidrag i det avslutande kapitlet som i kort visar på hur volym och valens kan variera i jämförelse med den tidigare forskningen som utförts och vad som bör beaktas och noggrant analyseras för att i framtiden kunna appliceras på företagsnivå inom marknadsföring såväl som rekommendationer.   Förslag till fortsatt forskning: Jämförande studie av de två begreppen eWOM och WOM, vilket är det mer traditionella uttryck för att beskriva en word of mouth effekt. Hur särskiljer sig dessa åt i resultat, och är de skillnader i effektivitet mot den som faktiskt blir rekommenderad.   Studien ger även förslag på att använda sig av demografiska data som underlag för tolkningen utav statistiken, vilket inte gjorts inom denna studie. Vi anser det även intressant med en mer övergripande manipulering av de olika profilerna, såsom att tillägga fabrik eller varumärke och se hur dessa skiljer sig åt.   Nyckelord: WTA, WTP, IRP, eWOM, WOM, Valens och Volym. / Abstract Title: Digitized word of mouth, an important factor for WTA   Level: Student thesis, final assignment for Bachelor Degree in Business Administration   Author: Andreas Ståhl and Markus Westblad   Supervisor: Jonas Kågström, Benny Berggren   Date: 2019 – June   Aim: The purpose of this study is to increase the understanding of how eWOM's volume and valency affects consumers' WTA in the choice of service from sellers. In this paper, a study of concepts such as WTA and eWOM has been compared in an experimental design which then through the result shared an understanding of how volume and valency affects the choice of a real estate agent. Through the previous research, the study has been desired to be applied to other industries previously performed, which we believe this study fulfills through the replicated method used.   Method: This study is conducted through a quantitative research strategy with a replicating method with experimental design. The data collected for the study's results and analysis has been collected through a digital survey with manipulated profiles through the recommendation site "Reco". The data has then been analyzed through the software "Jamovi" through descriptive analyzes and through a correlation matrix.   Result & Conclusions: The study has shown results that contradict previous research, among other things, that volume is more crucial in the choice of a service in relation to valency. This result also shows that companies should study their industries to increase their understanding of how strongly certain factors are within digitalized marketing.   Contribution of the thesis: The study presents a theoretical as well as practical contribution in the final chapter, which briefly shows how volume and valency can vary widely in relation to the previous research carried out and what should be considered and carefully analyzed in order to be able to apply at company level in marketing in the future. as recommendations.   Suggestions for future research: Comparative study of the two terms eWOM and WOM, which is the more traditional expression to describe a word of mouth effect. How do they differentiate in results, and are the differences in efficiency against the one that is actually recommended. The study also proposes to use demographic data as a basis for the interpretation of the statistics, which has not been done in this study. We also consider it interesting with a more general manipulation of the different profiles, such as adding factory or brand and seeing how these differ.   Key words: WTA, WTP, IRP, eWOM, WOM, Valency and Volume.
12

變數遺漏值的多重插補應用於條件評估法 / Multiple imputation for missing covariates in contingent valua-tion survey

費詩元, Fei, Shih Yuan Unknown Date (has links)
多數關於願付價格(WTP)之研究中,遺漏資料通常被視為完全隨機遺漏(MCAR)並刪除之。然而,研究中的某些重要變數若具有過高的遺漏比例時,則可能造成分析上的偏誤。 收入在許多條件評估(Contingent Valuation)調查中經常扮演著一個重要的角色,同時其也是受訪者最傾向於遺漏的變項之一。在這份研究中,我們將透過模擬的方式來評估多重插補法(Multiple Imputa- tion) 於插補願付價格調查中之遺漏收入之表現。我們考慮三種資料情況:刪除遺漏資料後所剩餘之完整資料、一次插補資料、以及多重插補資料,針對這三種情況,藉由三要素混合模型(Three-Component Mixture Model)所進行之分析來評估其優劣。模擬結果顯示,多重插補法之分析結果優於僅利用刪除遺漏資料所剩餘之完整資料進行分析之結果,並且隨著遺漏比例上升,其優劣更是明顯。我們也發現多重插補法之結果也比起一次插補來的更加可靠、穩定。因此如果資料遺漏機制非完全隨機遺漏之機制時,我們認為多重插補法是一個值得信任且表現不錯的處理方法。 此外,文中也透過「竹東及朴子地區心臟血管疾病長期追蹤研究」(Cardio Vascular Disease risk FACtor Two-township Study,簡稱CVDFACTS) 之資料來進行實證分析。文中示範一些評估遺漏機制的技巧,包括比較存活曲線以及邏輯斯迴歸。透過實證分析,我們發現插補前後的確造成模型分析及估計上的差異。 / Most often, studies focus on willingness to pay (WTP) simply ignore the missing values and treat them as if they were missing completely at random. It is well-known that such a practice might cause serious bias and lead to incorrect results. Income is one of the most influential variables in CV (contingent valuation) study and is also the variable that respondents most likely fail to respond. In the present study, we evaluate the performance of multiple imputation (MI) on missing income in the analysis of WTP through a series of simulation experiments. Several approaches such as complete-case analysis, single imputation, and MI are considered and com-pared. We show that performance with MI is always better than complete-case analy-sis, especially when the missing rate gets high. We also show that MI is more stable and reliable than single imputation. As an illustration, we use data from Cardio Vascular Disease risk FACtor Two-township Study (CVDFACTS). We demonstrate how to determine the missing mechanism through comparing the survival curves and a logistic regression model fitting. Based on the empirical study, we find that discarding cases with missing in-come can lead to something different from that with multiple imputation. If the dis-carded cases are not missing complete at random, the remaining samples will be biased. That can be a serious problem in CV research. To conclude, MI is a useful method to deal with missing value problems and it should be worthwhile to give it a try in CV studies.
13

Parent Preferences for Baby Formula in China and Potential Implications for U.S. Dairy Product Exports

Cui, Hao 01 January 2016 (has links)
As the world's most populous country, with more than 16 million births every year, China has emerged as a large importer of baby formula. China's relaxation of the one-child policy, which was announced in 2015, is expected to increase the number of births significantly and therefore increase the demand for Chinese and imported baby formula. While information on parent preferences for baby formula is very important for understanding and predicting China's import demand for baby formula and other products used to produce baby formula, like milk powder, there are very limited empirical studies on Chinese parent preferences for baby formula in the literature due to data limitation and other reasons. This research collects primary data from China through a parent survey, uses the data to analyze parent preferences and willingness to pay (WTP) for selected baby formula attributes, and derives implications for U.S. dairy product exports. Specifically, with detailed data from a total of 433 respondents, this study first examines parent purchase behavior of baby formula through descriptive analysis, then assesses parent preferences and WTP for selected baby formula attributes through the estimation of a random utility model, and finally derives implications for U.S. exports of milk powder, whey, and other dairy products. The descriptive analysis suggests that education level and income play an important role in parent purchase behavior of baby formula. The estimation results of the random utility model differed according to whether the survey was administered online or as a hardcopy. The results from the online survey indicate that imported, organic, and more reputable brands of baby formula are more attractive to respondents than domestic, non-organic, and less reputable brands. While respondents who completed the hardcopy survey also indicated a preference for organic baby formula from a reputable brand, they preferred domestic baby formula to imported formula. Further analysis of the WTP from the online survey for baby formula showed that parents have a strong preference and are willing to pay significantly more for baby formulas produced in Australia and the U.S. as compared to that produced in China. They are willing to pay more for organic baby formula and baby formula with an excellent reputation. The WTP results from the hardcopy survey indicate that parents are willing to pay more for domestic baby formula. They are also willing to pay more for organic baby formula and baby formula with an excellent reputation. China's emerging demand for imported baby formula, milk powder, and whey may bring more opportunities for the U.S. dairy industry, but U.S. dairy products are also facing increasing competition from similar products from other nations in the Chinese market. More studies are needed to identify the comparative advantages of U.S. baby formula and other dairy products in the Chinese market and to develop effective trade policies for enhancing U.S. exports to China.
14

Svenska konsumenters syn på sötnings-relaterad Front-of-package labeling

Ekstrand, Alexandra, Wiberg, Jasmine January 2019 (has links)
Sammanfattning Titel: En studie om hur Front-of-packaging påverkar konsumenters attityder. Nivå: C-uppsats, examensarbete i ämnet företagsekonomi. Författare: Alexandra Ekstrand och Jasmine Wiberg. Handledare: Jonas Kågström och Benny Berggren. Datum: 2019-05-24. Syfte: Vårt syfte är att skapa en djupare förståelse för hur konsumenter värderar sötnings-relaterade hälsopåståenden på livsmedelsförpackningar. Metod: I denna studie har en kvantitativ metod använts där 186 enkätsvar samlades in via en webbaserad undersökning som publicerades på sociala medier. Enkätsvaren analyserades i data- och statistikprogrammet Jamovi där deskriptiva analyser samt faktoranalyser genomfördes. Resultat & diskussion: Ett genomgående drag för i stort sett alla faktoranalyser är att WTP inte påvisar något starkt samband gentemot övriga variabler. Det finns dock ett tydligt samband mellan köpintention och de specifika påståendena i samtliga av faktoranalyser. Det vi funnit är främst att natur- och närvarofokuserade sötningspåståenden på produktförpackningar genererar högst WTP samt att vetenskaps- och närvarofokuserade påståenden ger lägst WTP hos konsumenterna inom denna produktkategori när sötning är i fokus. Uppsatsens bidrag: Undersökningen har främst bidragit genom att utveckla och fördjupa det teoretiska ramverk som André et al. (2018) skapat. Studien har även skapat en djupare inblick i huruvida FOP:ers utformning och karaktär påverkar konsumenters preferenser och WTP samt givit granola-producenter viss vägledning kring vilken karaktär hos påståenden som preferens. Förslag till vidare forskning: Ett exempel på vidare forskning är att ge studien en ny vinkel genom att följa Bonilla (2010, s. 11) tes om att utföra experimentella studier för ett mer verklighetsförankrat resultat. T.ex. genom att utföra ett experiment som innefattar respondenternas interaktion med verkliga produkter och verkliga pengar.
15

Efeitos do recebimento do lodo da estação de tratamento de água pelo sistema de tratamento de esgoto por lodo ativado em bateladas e aeração prolongada do município de Juquitiba - SP. / Effects of the accepting water treatment plants (WTP) residuals at wastewater treatment plant (WWTP) using SBR activated-sludge process with extended aeration in the city of Juquitiba, SP.

Sundefeld Júnior, Gilberto Carlos 09 May 2007 (has links)
Existem algumas diferentes soluções técnicas de engenharia para a finalidade de tratamento e disposição final dos resíduos gerados em ETA\'s aplicáveis aos diferentes sistemas de tratamento de água. Porém, depara-se com estações consolidadas sem os sistemas de tratamento da fase sólida, onde nem sempre a melhor solução para o tratamento é a mais econômica ou ainda, é a possível de ser implantada. Com isso propôs-se neste estudo avaliar a capacidade da estação de tratamento de esgotos receber os resíduos da ETA, da cidade de Juquitiba - SP, via rede coletora de esgotos, uma vez que existe na ETE o sistema de tratamento dos sólidos ali gerados. Este estudo teve como objetivo verificar as transformações do fósforo e do nitrogênio ao longo do sistema de esgotos, verificar as variações das concentrações de DBO, DQO e sólidos em suspensão, assim como verificar se é possível a manutenção de um equilíbrio consistente controlado pela idade do lodo. A estação de tratamento de água produz resíduos que resultariam em um acréscimo médio de 133 mg/L de sólidos no esgoto e ao longo deste estudo atingiu-se 74 mg/L. Esta contribuição representou, aproximadamente, uma situação em que o porte da ETA é o dobro da ETE receptora dos resíduos. Como conseqüência as concentrações dos sólidos em suspensão totais nos reatores biológicos aumentaram em média 15% e no efluente tratado 73%, ainda a produção de lodo biológico aumentou a ordem de 40%. Ocorreu a diminuição da concentração de fósforo total no efluente tratado da ETE em 29% e 51% para os reatores 1 e 2, respectivamente e da concentração de fósforo solúvel em 74% e 79% para os reatores 1 e 2, respectivamente. Ocorreu a diminuição da remoção média de NKT em 18% e na remoção média de N-NH3 em 13%. Ocorreu, ainda, a diminuição da remoção dos parâmetros DBO e DQO em 4% após o lançamento do lodo da ETA no sistema de esgotos. Pode-se então admitir que ETE\'s pelo processo de lodo ativado com aeração prolongada e com reatores seqüenciais em bateladas são adequados para o recebimento de lodo proveniente de ETA\'s, desde que projetada para atender a essa função complementar, especialmente no que se refere às unidades de desidratação de lodo. / There are different technical engineering solutions for the treatment and final disposal of water treatment plants (WTPs) residuals. Discharge of WTP residual to a wastewater treatment plant (WWTP) is a technical solution in evidence. Therefore, the purpose of this study was to evaluate the capacity of the WWTP using sequencing batch reactor (SBR) activated-sludge process (with two reactors named reactor 1 and 2) in the city of Juquitiba, State of São Paulo, to receive the WTP residuals by gravity sanitary sewers. For this purpose the following points were checked: phosphorous and nitrogen transformations in the sewer systems, variations in BOD , COD and suspended solids (SS) concentrations and the possibility of maintaining a consistent balance system controlled by solids retention time. There was an average increase of 74 mg of suspended solids per liter in incoming sewage by the discharge of WTP residuals to sanitary sewers. Suspended solids concentrations in the biological reactors increased 15 percent in average and 73 percent in the final effluent. Production of waste activated-sludge increased by 40 percent. There was a decrease of 29 percent and 51 percent of total phosphorus concentration in the effluent in reactors 1 and 2, respectively, and of 74 percent and 79 percent of soluble phosphorus concentration in reactors 1 and 2, respectively. Total Kjeldahl nitrogen removal efficiency was reduced by 18 percent and ammonia nitrogen removal efficiency by 13 percent. BOD and DQO parameters for efficiency removal showed a decrease of 4 percent after the discharge of WTP residual to sanitary sewers. In view of these results it can be admitted that WWTPs using sequencing batch reactor activated-sludge process are suitable to receive WTP residuals since adequately designed for this complementary function.
16

Uso da técnica produção mais limpa em estação de tratamento de efluentes industriais. / Use of cleaner production methodology in industrial wastewater treatment plants (WTP).

Harada, Franco Hamilton 11 May 2006 (has links)
Inserção da metodologia de Produção Mais Limpa em Estações de Tratamento de Efluentes (ETE) de indústrias no geral. O conceito fornecido pela Produção Mais Limpa permite sua aplicação aos tratamentos de fim de tubo, não se restringindo somente ao processo produtivo. A aplicação desta ferramenta visa um incremento e a melhoria contínua do sistema de gestão ambiental englobando o tratamento de todo o tipo de poluição gerada, especificamente neste trabalho, os efluentes industriais. As ETE, com um gerenciamento e operação adequados, além de minimizarem os efeitos poluidores dos efluentes gerados nas indústrias a níveis exigidos pela legislação aplicável ou a padrões de qualidade requeridos internamente em seu processo, podem controlar todo o processo produtivo interno a fábrica. Há a possibilidade de através dos diversos parâmetros processuais de controle detectar grande parte dos desvios produtivos ocorridos no interior da fábrica. Com a aplicação da ferramenta de Produção Mais Limpa em Estações de Tratamento de Efluentes Industriais, demonstra-se através de suas diversas metodologias: - A melhoria contínua em todos os processos produtivos e de tratamento de efluentes envolvidos na indústria; - O aumento progressivo das eficiências processuais; - Que investimentos e meio ambiente estão fortemente atrelados para o desenvolvimento da indústria e seu fortalecimento tanto a nível comercial quanto na sociedade. Portanto, a abordagem dada para a Produção Mais Limpa neste trabalho é mais abrangente - enfocando os tratamentos fim de tubo - as Estações de Tratamento de Efluentes Industriais. / The insertion in industries of Cleaner Production Methodology in Wastewater Treatment Plants (WTP). The concept given from the Cleaner Production allows its application to the end of pipe treatment, not restraining it to the productive process. The application of that tool aims the development and the continuous improvement of the environmental management system gathering the treatment of any type of generated pollution, specifically in this dissertation, the industrial wastewater. The WTP, with a suitable supervision and operation, not only minimizes the polluting effects of the effluents generated by the industries to levels demanded by the applicable legislation or to patterns of quality required internally in its process, but also can control the whole factory intern productive process. There is the possibility of detecting great part of the productive deviation that occurred in the interior of the factory through many controlling processual parameters. With the application of the tool of Cleaner Production in the Treatment Stations of Industrial Effluents, it demonstrates through many of its methodologies: - The continuous improvement in all of the productive and treatment processes of effluents involved in the industry; - The progressive enlargement of the processual efficiency; - Which investments and environment are strongly related to the development of the industry and its strengthening both on commercial and social levels. Therefore, the approach given to the Cleaner Production in this dissertation is wider - focusing the end of pipe treatment - the Treatment Stations of Industrial Effluents.
17

Efeito do recebimento de lodos oriundos de estações de tratamento de água nos processos de tratamento de esgotos por lodos ativados convencional. / Effects of Water Treatment Plant (WTP) sludge on a Waste Water Treatment Plant (WWTP) with active sludge process.

Marguti, André Luiz 13 April 2012 (has links)
Por razões técnicas e ambientais, o lodo gerado no tratamento de águas para abastecimento público deve ser adequadamente tratado antes de ser disposto no meio ambiente. Uma alternativa é a disposição do lodo de ETA em ETE, o que dispensa a implantação da linha de tratamento do lodo na ETA. O objetivo deste trabalho foi estudar os impactos ocorridos na ETE ABC, estação de lodos ativados convencional operada pela SABESP, devido ao recebimento do lodo da ETA Rio Grande. Trata-se de caso particular, pois envolve instalações reais, e pelo fato de a ETA apresentar vazão próxima de três vezes a vazão da ETE (vazão de lodo corresponde a 0,1% da vazão da ETE). Os dados utilizados incluem variáveis de qualidade do efluente (DBO, DQO, SST, SSV, nitrogênio amoniacal e total, fósforo e ferro) e do lodo (sólidos), e parâmetros operacionais das unidades da ETE (vazões, taxas de aplicação superficial e de sólidos, idade do lodo, tempo de detenção, entre outros). Foi possível analisar o processo de tratamento na ETE e comparar seu desempenho entre dois períodos: controle (anos de 2005 e 2006) e com lodo (janeiro de 2007 a março de 2008). Nestes períodos, a ETE operou com 50% de sua capacidade (taxas de aplicação abaixo dos valores de projeto), idade do lodo de 4 dias e taxa de reciclo em torno de 80%. No período com lodo, as variáveis que apresentaram maior aumento de concentração no esgoto afluente foram SST, SSV, fósforo e ferro; o lodo da ETA contribuiu para maiores eficiências de tratamento da fase líquida na ETE, uma vez que houve a manutenção da qualidade do efluente final, nos níveis exigidos pela legislação, mesmo com o aumento das concentrações afluentes. Este aumento de eficiência foi mais acentuado para o fósforo (de 52% para 88%), e maior no tratamento primário, com variações nos parâmetros operacionais que não influíram negativamente no desempenho das unidades. No tratamento de lodo, o maior impacto causado foi o aumento na produção final de lodo (de 50 t/d para 76 t/d). Tais conclusões são então favoráveis ao lançamento de lodos de ETA convencional em ETE de lodos ativados convencional, mesmo nos casos em que a vazão tratada na ETA exceda em muito a vazão da ETE. / For technical and environmental reasons, sludge from water treatment plants should be properly treated before being discharged into the environment. An emerging practice is the disposal of such sludge in WWTP, an alternative that does not require the installation of sludge treatment facilities in the WTP. The main purpose of this research was to study the impacts at the ABC WWTP, an activated sludge process facility operated by SABESP and located in São Paulo, Brazil, due to receiving sludge from the Rio Grande WTP, also located in the same region. It is a particular case due to the fact that the WTP provides a flow of three times the flow treated in the WWTP (sludge flow is 0,1% of WWTP flow). The used data include effluent quality variables (BOD, COD, TSS, VSS, ammonia and total nitrogen, phosphorus and iron), sludge (solids) and WWTP units operational parameters (flow, surface and solid application rates, sludge retention time, hydraulic detention time, among others). It was possible to analyze the treatment process at the WWTP and compare its performance between two periods: control (years 2005 and 2006) and with sludge (from January 2007 to March 2008). In these periods, the WWTP worked with half of its capacity (all loading rates stayed below design values), sludge retention time of 4 days and recycle rate around 80%. In the with sludge period, the quality variables with the highest inflow concentration increase were TSS, VSS, phosphorus and iron. During the same period, the WTP sludge contributed to greater efficiencies in the WWTP treatment process, since the effluent quality was maintained under levels legally required, even with the increase of influent concentrations. This fact is mostly evident in the case of phosphorus (from 52% to 88%), and higher in primary treatment, with changes in operational parameters that did not adversely affect the units performances. In solid phase treatment, the most important impact was the increase in final sludge production (from 50 t/d to 76 t/d). These conclusions are then favorable to the disposal of sludge from conventional WTP in an activated sludge WWTP, even in cases in which the flow treated in the WTP far exceeds the WWTP flow.
18

Efeitos do recebimento do lodo da estação de tratamento de água pelo sistema de tratamento de esgoto por lodo ativado em bateladas e aeração prolongada do município de Juquitiba - SP. / Effects of the accepting water treatment plants (WTP) residuals at wastewater treatment plant (WWTP) using SBR activated-sludge process with extended aeration in the city of Juquitiba, SP.

Gilberto Carlos Sundefeld Júnior 09 May 2007 (has links)
Existem algumas diferentes soluções técnicas de engenharia para a finalidade de tratamento e disposição final dos resíduos gerados em ETA\'s aplicáveis aos diferentes sistemas de tratamento de água. Porém, depara-se com estações consolidadas sem os sistemas de tratamento da fase sólida, onde nem sempre a melhor solução para o tratamento é a mais econômica ou ainda, é a possível de ser implantada. Com isso propôs-se neste estudo avaliar a capacidade da estação de tratamento de esgotos receber os resíduos da ETA, da cidade de Juquitiba - SP, via rede coletora de esgotos, uma vez que existe na ETE o sistema de tratamento dos sólidos ali gerados. Este estudo teve como objetivo verificar as transformações do fósforo e do nitrogênio ao longo do sistema de esgotos, verificar as variações das concentrações de DBO, DQO e sólidos em suspensão, assim como verificar se é possível a manutenção de um equilíbrio consistente controlado pela idade do lodo. A estação de tratamento de água produz resíduos que resultariam em um acréscimo médio de 133 mg/L de sólidos no esgoto e ao longo deste estudo atingiu-se 74 mg/L. Esta contribuição representou, aproximadamente, uma situação em que o porte da ETA é o dobro da ETE receptora dos resíduos. Como conseqüência as concentrações dos sólidos em suspensão totais nos reatores biológicos aumentaram em média 15% e no efluente tratado 73%, ainda a produção de lodo biológico aumentou a ordem de 40%. Ocorreu a diminuição da concentração de fósforo total no efluente tratado da ETE em 29% e 51% para os reatores 1 e 2, respectivamente e da concentração de fósforo solúvel em 74% e 79% para os reatores 1 e 2, respectivamente. Ocorreu a diminuição da remoção média de NKT em 18% e na remoção média de N-NH3 em 13%. Ocorreu, ainda, a diminuição da remoção dos parâmetros DBO e DQO em 4% após o lançamento do lodo da ETA no sistema de esgotos. Pode-se então admitir que ETE\'s pelo processo de lodo ativado com aeração prolongada e com reatores seqüenciais em bateladas são adequados para o recebimento de lodo proveniente de ETA\'s, desde que projetada para atender a essa função complementar, especialmente no que se refere às unidades de desidratação de lodo. / There are different technical engineering solutions for the treatment and final disposal of water treatment plants (WTPs) residuals. Discharge of WTP residual to a wastewater treatment plant (WWTP) is a technical solution in evidence. Therefore, the purpose of this study was to evaluate the capacity of the WWTP using sequencing batch reactor (SBR) activated-sludge process (with two reactors named reactor 1 and 2) in the city of Juquitiba, State of São Paulo, to receive the WTP residuals by gravity sanitary sewers. For this purpose the following points were checked: phosphorous and nitrogen transformations in the sewer systems, variations in BOD , COD and suspended solids (SS) concentrations and the possibility of maintaining a consistent balance system controlled by solids retention time. There was an average increase of 74 mg of suspended solids per liter in incoming sewage by the discharge of WTP residuals to sanitary sewers. Suspended solids concentrations in the biological reactors increased 15 percent in average and 73 percent in the final effluent. Production of waste activated-sludge increased by 40 percent. There was a decrease of 29 percent and 51 percent of total phosphorus concentration in the effluent in reactors 1 and 2, respectively, and of 74 percent and 79 percent of soluble phosphorus concentration in reactors 1 and 2, respectively. Total Kjeldahl nitrogen removal efficiency was reduced by 18 percent and ammonia nitrogen removal efficiency by 13 percent. BOD and DQO parameters for efficiency removal showed a decrease of 4 percent after the discharge of WTP residual to sanitary sewers. In view of these results it can be admitted that WWTPs using sequencing batch reactor activated-sludge process are suitable to receive WTP residuals since adequately designed for this complementary function.
19

Temporal distance and the endowment effect

Ko, Dong Woo 01 May 2013 (has links)
The endowment effect occurs when owners assign more value to the products they own than do non-owners to the same products. Research on the endowment effect has identified factors that enhance or mitigate the effect, such as the duration of ownership, as well as information processing differences between sellers and buyers. However, these studies have primarily involved immediate transactions between sellers and buyers. An interesting question emerges as to whether the endowment effect will be observed for temporally distant transactions. The main purpose of the first two studies is to examine how the temporal distance from transactions influences customers' evaluations of products by comparing buyers' willingness to pay and sellers' willingness to accept in the present and future. Despite the fact that consumers often collect information today about product or services that will be consumed in the future, such as window shopping or looking at houses or cars for a future purchase, a limited number of endowment studies have considered the temporal effect on willingness to pay and willingness to accept. More specifically, studies 1, 2, and 3 find that the endowment effect disappears as temporal distance from the transaction increases. Study 2 and 3 demonstrates that when the transaction is expected to occur in the near future, sellers focus on their products, while buyers focus on their money. These different cognitive perspectives affect price gaps between sellers and buyers. Specifically study 2 demonstrates that when events are in the distant future, sellers' and buyers' cognitive perspectives change, and the endowment effect is eliminated. In study 3, the effects of role and time on memory trace and information structure were investigate to investigate the salience differences in transaction. Finally, the underlying psychological and temporal mechanism driving the salience differences investigated in study 4-a and 4-b.
20

Decision Analysis Considering Welfare Impacts in Water Resources Using the Benefit Transfer Approach

Shaqadan, Ashraf 01 May 2008 (has links)
Decision making in environmental management is faced with uncertainties associated with related environmental variables and processes. Decision makers are inclined to use resources to acquire better information in one or more uncertain variable(s). Typically, with limited resources available, characterizing the feasibility of such investment is desirable yet complicated. In the context of reducing inherent uncertainty, decision makers need to tackle two difficult questions, first, the optimal selection of variable(s) and second, the optimal level of information collection which produces maximum gain in benefits. We develop a new framework to assess the socioeconomic value of potential decisions of collecting additional information for given variable(s) to reduce inherent uncertainty. The suggested framework employs advanced social welfare concepts to facilitate eliciting the social acceptability of decisions to collect better information. The framework produces estimates of changes in utility levels and willingness to pay for target population using the benefit transfer method. The practicality of the framework is established using the following common problems in the field of water resources: 1) the uncertainty in exposure to health risk due to drinking a groundwater source contaminated with a carcinogen, 2) the uncertainty in non point source pollution loadings due to unknown hydrologic processes variability, and 3) the equity level in allocating mitigation responsibilities among polluters. For the three applications, the social acceptability of potential decisions is expressed in monetary terms which represent an extension on typical cost benefit analysis by including the socioeconomic value of a decision. The specific contribution of this research is a theoretical framework for a detailed preliminary analysis to transform and represent the given problem in useable terms for the social welfare analysis. The practical framework is attractive because it avoids the need to employ prohibitively expensive survey-based contingent valuation methods. Instead, the framework utilizes benefit transfer method, which imposes a theoretical behavioral structure on population characteristics such as age and income and to produce empirical estimates for a new problem setting.

Page generated in 0.0496 seconds