988 resultados para green processes


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Excited state absorption and excited state dynamics of indocyanine-green (ICG) dissolved in dymethyl sulfoxide were measured using white-light continuum Z-scan (WLCZScan) and white-light continuum pump-probe (WLCPP) techniques. The excited state absorption spectrum, obtained through Z-scan measurements, revealed saturable absorption (SA) for wavelengths longer than 630 nm, while reverse saturable absorption (RSA) appeared, as indicated by a band at approximately 570 nm. Both processes were modeled by a three-energy-level diagram, from which the excited state cross-section values were determined. SA and RSA were also observed in pump-probe experiments, with a recovery time in the hundreds of picoseconds time scale due to the long lifetime of the first excited state of ICG. Such results contribute to the understanding of ICG optical properties, allowing application in photonics and medicine. Copyright (C) 2010 John Wiley & Sons, Ltd.

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The inactivation kinetics of enzymes polyphenol oxidase (PPO) and peroxidase (POD) was studied for the batch (discontinuous) microwave treatment of green coconut water. Inactivation of commercial PPO and POD added to sterile coconut water was also investigated. The complete time-temperature profiles of the experimental runs were used for determination of the kinetic parameters D-value and z-value: PPO (D(92.20 degrees C) = 52 s and z = 17.6 degrees C); POD (D(92.92 degrees C) = 16 s and z = 11.5 degrees C); PPO/sterile coconut water: (D(84.45 degrees C) = 43 s and z = 39.5 degrees C) and POD/sterile coconut water: (D(86.54 degrees C) = 20 s and z = 19.3 degrees C). All data were well fitted by a first order kinetic model. The enzymes naturally present in coconut water showed a higher resistance when compared to those added to the sterilized medium or other simulated solutions reported in the literature. The thermal inactivation of PPO and POD during microwave processing of green coconut water was significantly faster in comparison with conventional processes reported in the literature. (C) 2008 Elsevier Ltd. All rights reserved.

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The photocatalytic degradation of Janus Green B azo dye over silver modified titanium dioxide films was investigated by surface-enhanced Raman spectroscopy (SERS). An optimized SERS-active substrate was employed to study the photodegradation reaction of Janus Green B. Considering that photocatalytic degradation processes of organic molecules adsorbed on TiO2 might involve either their oxidation or reduction reaction, the vibrational spectroelectrochemical study of the dye was also performed, in order to clarify the transformations involved in initial steps of its photochemical decomposition. In order to understand the changes in Raman spectra of Janus Green B after photodegradation and/or electrochemical processes, a vibrational assignment of the main Raman active modes of the dye was carried out, based on a detailed resonance Raman profile. Products formed by electrochemical and photochemical degradation processes were compared. The obtained results revealed that the first steps of the degradation process of Janus Green B involve a reductive mechanism. (C) 2007 Published by Elsevier B.V.

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This article reports the preliminary findings on the morphology, chemical structure, antimicrobial and UV-screening properties of bamboo fibres. Bamboo fibres provide a very promising alternative to other natural fibres by virtue of their distinctive characteristics such as eco-friendly farming, inherent antimicrobial, UV-protective and highly· breathable properties. However, these novel properties are moslly claimed by fibre manufacturers, with little scientific evidence.  Moreover, those properties may largely depend on the manufacturing process, which is not widely disclosed by the manufacturers, Common manufacturing processes may require the use of a large amount of chemicals which would not make the product truly eco-friendly. Therefore, there is a strong need for unbiased laboratory experiments being conducted in a rigorous manner to elucidate the origin of those unique properties of bamboo fibres and to develop new processing methods to effectively utilise the properties in the final products. This research is aimed to prove the unique characteristics of bamboo fibres scientifically and to develop an efficient manufacturing process, in order to establish the place of bamboo fibres as a novel green material.

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A series of rare earth organic compounds pioneered by our group have been shown to provide a viable alternative to theuse of chromates as corrosion inhibitors for some steel and aluminium applications. For example we have shown thatthe lanthanum 4-hydroxy cinnamate offers excellent corrosion mitigation for mild steel in aqueous environments whilerare earth diphenyl phosphates offer the best protection in the case of aluminium alloys. In both cases the protectionappears to be related to the formation of a nanometre thick interphase occurring on the surface that reduces theelectrochemical processes leading to metal loss or pitting. Very recent work has indicated that we may even be able toaddress the challenging issue of stress corrosion cracking of high strength steels. Furthermore, filiform corrosion can besuppressed when selected rare earth inhibitor compounds are added as pigments to a polymer coating. There is little doubtfrom the work thus far that a synergy exists between the rare earth and organic inhibitor components in these novelcompounds. This paper reviews some of the published research conducted by the senior author and colleagues over the past10 years in this developing field of green corrosion inhibitors

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This paper presents a framework on how Small and Medium Enterprises (SMEs) can proactively incorporate content relating to their ecological responsibility (or green) activities in their websites. SME studies offer limited guidance on, and conceptualisation of, how organisations can incorporate different types of content into their website designs. This paper addresses this problem by presenting the results of an exploratory, qualitative content analysis of Australian SME websites where emergent themes are interpreted using framing and legitimacy theories. It describes three dimensions (location, presentation, and specificity) which comprise the framework, under which the themes are grouped. The paper outlines how scholars can use the framework to develop models and carry out evaluations regarding how SMEs embed green content, and potentially other specific content types, in their websites. It also summarises how the framework can assist SMEs (or website developers serving them) make informed decisions regarding framing their websites as green, or de-emphasising this content, by paying attention to its location (e.g. homepage, navigation bars) and presentation (e.g. how paragraphs, images, etc are used) within webpages. The legitimacy or credibility of the green content can be enhanced using different types of specificity (e.g. statistics, detail of processes and actions, and third-party substantiation).

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The management of a firm's green operations is increasingly important for marketing strategists. The purpose of this study is to investigate the cross-influences of green marketing strategy and the key internal green functional areas in a firm. We use the antecedents of marketing strategy and identify relationships between green marketing strategy and key supporting internal environmental operations of firms with respect to (1) green suppliers, (2) environmental resource management, (3) green research and development, and (4) environmental manufacturing processes and procedures. The statistical techniques of parallel analysis, factor analysis and multiple regressions are used to analyze data collected from 332 firms. The results identify that among the four functional areas of firms adopting green marketing strategy. Two are more likely to influence green marketing strategy – supplier selection and research and development. Implications are discussed. The findings contribute to the theory of green marketing strategy. Future research is recommended.

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The management of a firm's green operations is increasingly important for marketing strategists. The purpose of this study is to investigate the cross-influences of green marketing strategy and the key internal green functional areas in a firm. We use the antecedents of marketing strategy and identify relationships between green marketing strategy and key supporting internal environmental operations of firms with respect to (1) green suppliers, (2) environmental resource management, (3) green research and development, and (4) environmental manufacturing processes and procedures. The statistical techniques of parallel analysis, factor analysis and multiple regressions are used to analyze data collected from 332 firms. The results identify that among the four functional areas of firms adopting green marketing strategy. Two are more likely to influence green marketing strategy – supplier selection and research and development. Implications are discussed. The findings contribute to the theory of green marketing strategy. Future research is recommended.

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This chapter presents the fundamentals of “green” marketing by drawing on traditional marketing theory as well as researchfocused on green marketing context. It discusses five critical areas in green marketing. The first critical area stems from green marketingtheory and practice that examines the logic for reducing the environmental impact of value creation and exchange. The second criticalarea highlights green marketing strategy that focuses on achieving organizational goals in ways that can reduce or eliminate negativeimpacts on the natural environment. The third critical area examines the green marketing mix that accounts for green products, greendistribution, green pricing, and green promotion. By using traditional marketing concepts, the chapter identifies how the entiremarketing mix elements should consistently provide a complete green product offering. Green products and processes need to beresearched, designed, and manufactured to include environmentally safe ingredients and components. Products need to be strategicallypriced to reflect their green values, distributed in the green chain channels and displayed effectively to highlight their status, and accuratelycommunicated to consumers and stakeholders. The fourth critical area illustrates governance and control. It shows how theholistic transformation toward greening the organization requires organizational culture change to gain support within and outside thefirm to ensure environmental issues are appropriately considered. These can be assessed by using existing management mechanisms,such as environmental management systems and/or triple bottom line management, which ensure best practice and continuousimprovements to occur. Lastly, the chapter discusses the future of green marketing and the direction that businesses need to take if theyseek to be sustainable.

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Red, green, and blue emission through frequency upconversion and energy-transfer processes in tellurite glasses doped with Tm3+ and Er3+ excited at 1.064 mum is investigated. The Tm3+/Er3+-codoped samples produced intense upconversion emission signals at around 480, 530, 550 and 660 nm. The 480 nm blue emission was originated from the (1)G(4)-->H-3(6) transition of the Tm3+ ions excited by a multiphoton stepwise phonon-assisted excited-state absorption process. The 5 30, 5 50 nm green and 660 mn red upconversion luminescences were identified as originating from the H-2(11/2), S-4(3/2) --> I-4(15/2) and F-4(9/2) --> I-4(15/2) transitions of the Er3+ ions, respectively, populated via efficient cross-relaxation processes and excited-state absorption. White light generation employing a single infrared excitation source is also examined. (C) 2003 Elsevier B.V. (USA). All rights reserved.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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This study aimed to evaluate the efficiency of natural biocides, brown and green propolis, for the control of bacterial contamination in the production of sugarcane spirit. The treatments consisted of brown and green propolis extracts, ampicillin, and a control and were assessed at the beginning and end of harvest season in ten fermentation cycles. In the microbiological analyses, the lactic acid bacteria were quantified in the inoculum before and after the treatment with biocides, and the viability of yeast cells during fermentation was evaluated. The levels of acids, glycerol, total residual reducing sugars, and ethanol were analyzed for the wine resulting from each fermentation cycle. A reduction in the number of bacterial contaminants in the inoculum in the treatments with the natural biocides was observed, but it did not affect the viability of yeast cells. The control of the contaminants led to the production of higher levels of ethanol and reduced acidity in the wine produced. The results of the use of brown and green propolis to control the growth microorganisms in the fermentation of sugarcane spirit can be of great importance for using alternative strategies to synthetic antibacterials in fermentation processes including other distilled beverage or spirits.