460 research outputs found
Avaliação in vitro do efeito da desproteinização da dentina decídua de humanos na união de sistemas adesivos
No full textTese (doutorado) - Universidade Federal de Santa Catarina, Centro de Ciências da Saúde, Programa de Pós-Graduação em Odontologia, Florianópolis, 2009.O objetivo deste estudo, in vitro, foi avaliar a resistência de união à microtração e a nanoinfiltração, após desproteinização da dentina decídua humana. Foram utilizadas coroas de molares decíduos hígidos, as quais tiveram a superfície oclusal desgastada com lixas de carbeto de silício, até a completa exposição da superfície dentinária, e para padronização da smear layer. Os espécimes foram distribuídos em seis grupos, de acordo com o tipo de tratamento (condicionamento ácido - CA ou CA + hipoclorito de sódio - NaOCl) e os sistemas adesivos: One Step Plus - Bisco (OSP), Single Bond - 3M ESPE (SB), Prime & Bond 2.1 - Dentsply (PB). Para o procedimento de desproteinização foi utilizado hipoclorito de sódio 10% por 30s. Os sistemas adesivos e a resina (Filtek Z 250 - 3M ESPE) foram aplicados de acordo com as recomendações dos fabricantes e os espécimes armazenados em água destilada (37ºC/24h). As coroas foram seccionadas obtendo-se palitos (0,8mm2), os quais foram imediatamente submetidos ao teste de resistência à microtração (Instron - 0,5mm/min), até fratura dos corpos-de-prova. Os valores obtidos foram analisados por ANOVA e teste de Tukey (p<0,05). Os corpos-de-prova foram levados ao microscópio eletrônico de varredura (MEV), para visualização do tipo de fratura e os dados submetidos ao teste de Kruskal-Wallis (p<0,05).A nanoinfiltração foi avaliada utilizando-se palitos e nitrato de prata amoniacal como marcador químico. A deposição da prata foi visualizada ao MEV e analisada de duas formas: 1. Em porcentagem (%), em três regiões do palito, utilizando-se espectometria por energia dispersa por raio-x (EDS); 2. Atribuição de escores pela avaliação das fotomicrografias obtidas ao MEV. Os dados (%) foram analisados por ANOVA e teste de Tukey (p<0,05) e os escores submetidos aos testes de Kruskal-Wallis e U de Mann-Whitney (p<0,05).Os valores médios obtidos para o teste de microtração sem desproteinização foram [MPa(DP)]: PB - 35,95(6,12); SB - 28,82(6,38); OSP - 24,59(6,10); e após desproteinização: PB - 41,47(6,79); OSP - 31,09(9,16); SB - 25,55(7,23). Os padrões de fratura mais comumente encontrados foram coesiva do adesivo e mista, para todos os grupos. A nanoinfiltração, avaliada por porcentagem, apresentou diferença significante para as variáveis tratamento e adesivo. A desproteinização da dentina condicionada reduziu significativamente a infiltração para o adesivo OSP. Para a variável sistema adesivo, na análise por porcentagem e por escores, o adesivo SB apresentou significativamente maior infiltração pelo nitrato de prata quando comparado ao OSP e PB, que foram similares entre si. Conclui-se que a resistência adesiva não foi influenciada pela remoção do colágeno exposto pelo condicionamento ácido e que a nanoinfiltração não foi evitada pela desproteinização dentinária
Green and greener solvents in photographic conservation
No full textGreen chemistry and sustainability are known to be the keywords for the next era of the conservation of cultural heritage. Since the 1980s, environmental issues have changed the prospects for market orientation, both in the production of photographic and film materials. This paper aims to provide information on an ongoing research that has been carried out on the application of ‘green’ and ‘greener’ solvents for the removal of stain and adhesives. Diethyl carbonate, limonene, ethyl lactate, and eucalyptus oil were evaluated when applied in free form and solvent gels. Before and after the treatments scientific analysis was carried out to determine their effectiveness and the persistence of residues
A novel Bayesian inference method for predicting optimum strength gain in sustainable geomaterials for greener construction
No full textThere has been growing research interests in the study of sustainable geomaterials to reduce or replace the use of cement to promote greener construction. A machine learning technique based on Bayesian inference was proposed in this study to predict the optimum strength gain in sustainable geomaterials as an alternative to preliminary investigation of new materials and to supplement existing experimental design process. The proposed novel methodology was implemented using two established case studies on sustainable geomaterials previously studied by the second author: (i) fly ash-based geopolymer concrete and (ii) sustainable cementitious blends for soft soil stabilization in order to validate the proposed Bayesian methodology for wider application considering efficiency and sustainability as opposed to performing excessive conventional laboratory-based destructive tests. The eventual results show that the proposed Bayesian approach, which implements the 3-stage data training, validating, and updating process could reliably and accurately predict the strength of geomaterials, despite them having very different mix design requirements.Full Tex
Eco-industrial development in the U.S. spatial forms, contextual factors, and institutional fabrics of greener plants and offices
No full textThe main goal of this dissertation is to examine the current practices and strategies of eco-industrial development in the U.S. Traditional studies of eco-industrial development focus on successful case studies and their internal systems, but overlook external systems enabling those cases. By reconsidering eco-industrial development from the viewpoint of agglomeration economies, this dissertation investigates the spatial forms and contextual factors of greener plants and offices as key actors in potential eco-industrial developments, and the institutional fabrics of on-going eco-industrial developments to identify potentially favorable locations for eco-industrial developments. Spatial forms of eco-industrial developments tend to follow given geographical distributions of plants in the industrial context and of offices in the post-industrial context. The exploratory spatial data analyses and regression analyses illustrate that larger and greener plants in selected pollution-intensive industries tend to cluster in and around a group of major U.S. cities. Greener offices are also likely to be located in and near the similar group of cities, as revealed from the descriptive analyses. Selected contextual factors appear to influence the environmental performance and locational behavior of greener plants and offices significantly. Through a series of regression analyses, it is revealed that the economic performance of larger and greener plants is largely conditioned by the internal economies of scale, and the environmental performance is by factors of localization economies. The event-history analyses and panel data analyses of greener offices show that demographic, economic, governmental, and geographic factors have considerable impacts on the adoption speed and size of green building projects at the county level. Factors associated with urbanization economies seems to work significantly in the diffusion of green buildings in the U.S. Institutional fabrics of on-going eco-industrial developments are probed by a series of case studies on the Rutgers EcoComplex, the regional By-Product Synergy projects, and green towers at Battery Park City in Manhattan. Findings from case studies support the importance of balanced institutional building processes between local communities and non-local networks. The pre-existence of enlightened local anchor is instrumental, while the role of non-local anchor as enabler or facilitator in local eco-industrial development deserves more attention.Ph.D.by Mook Han KimIncludes abstractVitaIncludes bibliographical reference
Spread of retailer food quality standards: an international perspective
No full textPrivately initiated food quality standards are currently important elements in the marketing of food and agricultural products. At the same time, they stand in the centre of a discussion about potential negative effects on small farmers and farmers in developing countries. This study aims at analysing the adoption of two private food standards, BRC Technical Food Standard and GlobalGAP, at an aggregated crosscountry level. The results of the econometric analysis reveal some (potential) barriers for developing countries to access this type of organisational innovation. Certificates seem to be issued more probably in larger and wealthier countries, countries with a better institutional quality, better infrastructural conditions and in former UK colonies
Spread of retailer food quality standards: An international perspective
No full textPrivately initiated food quality standards are currently important elements in the marketing of food and agricultural products. At the same time, they stand in the centre of a discussion about potential negative effects on small farmers and farmers in developing countries. This study aims at analysing the adoption of two private food standards, BRC Technical Food Standard and GlobalGAP, at an aggregated cross-country level. The results of the econometric analysis reveal some (potential) barriers for developing countries to access this type of organisational innovation. Certificates seem to be issued more probably in larger and wealthier countries, countries with a better institutional quality, better infrastructural conditions and in former UK colonies.standards, food quality, adoption, Food Consumption/Nutrition/Food Safety,
Reducing the environmental impact of gloves used in the Intensive Care Unit: Towards greener ICUs
No full textBackgroundThe healthcare sector is one of the most polluting sectors in the Netherlands. To limit the environmental impact of the medical sector, Erasmus MC collaborated with Metabolic to conduct a Material Flow Analysis (MFA) and Impact Assessment for the Intensive Care Unit (ICU). The research revealed the hotspots of the ICU, contributing to this polluting sector. Based on the hotspots The Convergence, a cooperation between the Erasmus University, Erasmus MC, and TU Delft have set up the first three design projects. Project aimThis graduation project aimed to make a start towards greener ICUs. In the ICU care is delivered to critically ill patients. The number of gloves used is high because of the intensity of care and high standards. Due to its resource-intensive production and frequency of use, the use of nitrile disposable gloves was found as a hotspot. The question to be answered was; How could the environmental impact of gloves in the ICU be reduced, while remaining quality of care? ResearchExtensive research is done with different focuses; product-centred, human-centred and material centred. Furthermore, the waste from the PICU was analysed for one week. The research revealed the importance of the procurement department and the Unit Infection Prevention. Design directionTogether with the nursing staff, it was decided to go for the design direction of reducing the number of unused gloves. The scope was set to the current situation in the ICU and the idea should be implementable in the short term. The research resulted in five building blocks for the design that need to be incorporated; (1) infection prevention, (2) zero-risk, (3) ease of use, (4) efficiency and (5) technology. IdeationIdeation was done by involving people in creative sessions. Restrictions were excluded in the creative sessions, to come up with a wide range of ideas. Three ideas were chosen based on their short-term implementation possibility and incorporation of the building blocks. The ideas were presented to the Green Team of the ICU and it was decided to go on with an addition of the current box and applying a different way of dispensing gloves. Prototyping and testingPrototypes were made to quickly verify the functioning of the ideas. While testing the prototypes, iterations were applied. A user evaluation was performed and resulted in a preference for the vertical dispensing design. Final designThe final design is GloVe, a vertical dispense system. By incorporating the five building blocks, the design can provide benefits for multiple stakeholders. It reduces the environmental impact of gloves in the ICU by dispensing one glove at a time. Furthermore, the gloves are dispensed at the cuff, which comes in little contact with the patient. The vertical movement is pleasant to the user. The use of colour for different sizes makes it clear to the care assistant which box should go in which holder. Also, nurses will see at a glance, which size gloves they are dispensing. The small V-shaped opening makes the undesirable behaviour, of placing gloves back, almost impossible. Transformation towards greener ICUs The design thinking approach has yielded a design, insights, and recommendations for subsequent projects. Furthermore, the project has drawn a lot of attention to making healthcare more sustainable. The project has been a necessary start towards more sustainable ICUs.Integrated Product Design | Medisig
An Examination of the Globalisation of Authorship in Publishing in 20 Leading Marketing Journals
No full textPurpose of this paper is to examine the global contribution of academics to marketing literature between 1999 and 2003, based on an examination of the location of academics institution of employment, as reported in published works. The data is used to evaluate the global dispersion of publishing.\ud
Design/approach. The paper uses the method of content analysis where the authorship of all articles in 20 leading marketing journals between 1999 and 2003 is examined. An empirical examination of performance was undertaken across geographic regions. There was also an examination of whether the quality of journal affected regional performance.\ud
Findings. The research found that there is a significant "bias" of authorship within the 20 journals examined, with the majority of works published by academics at institutions in North America. There is some variation in regional performance based on the type of journal examined. Limitations. There was no attempt to empirically examine why differences might exist. The study only focused on a sample of 20 English language journals over 5 years. These journals have been included in studies that list the leading marketing journal for US and European academics. Practical Implications. The research suggests that there may in fact be regional differences in publishing behaviour. It is unclear if these differences relate to variations in the "objectives" of institutions within each country or other factors, such as the North American publish-or-perish mentality. The research posits that a marketing knowledge may be unnecessarily restricted, if there is a bias against non-North American perspectives. Originality. While there have been other works examining research performance of institutions, there has been limited examination in marketing on the nation in which authors work and none have used a broad cross-section of journals. This work takes a global "snapshot" of national research performance within marketing
Metrics of green chemistry: Waste minimization
No full textThe increasingly apparent negative impact of human activities on the environment has heightened the urgency for the chemistry community to adopt greener and more sustainable practices. The E-factor can still be considered a valuable tool in this drive, particularly because of its broad acceptance and familiarity amongst both industrial and academic chemists. An important factor in broadening the adoption of green principles is ensuring that the academics responsible for training the next generation of chemists prioritise green and sustainable practices in their undergraduate and post graduate laboratories. Green metrics must be easy to use to motivate the broader chemistry community to develop greener syntheses. For maximum impact to be achieved the detail of the exact green metrics applied are less important than their adoption by the broader chemical community. Of growing importance is the replacement of fossil resources with renewable alternatives to reduce greenhouse gas emission that is a significant driver of climate change. The C factor is used to compare the carbon footprints of different routes to a particular product.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.BT/Biocatalysi
- …
