Tourism, poverty alleviation and nature conservation : the state of contemporary research

Artikkeli perustuu kirjallisuuskatsaukseen, joka on tehty 17 lehden 112 vertaisarvioidusta artikkelista vuosilta 2003-2007.

MANOBRAS DE SEMEADURA COM SISTEMA DE NAVEGAÇÃO

Resumo Os sistemas de navegação por posicionamento global (GPS) estão cada vez mais presentes no campo, prometendo diminuir os custos operacionais do agricultor. O objetivo deste trabalho foi avaliar o tempo de manobra durante a operação de semeadura da soja sem e com sistema de navegação. O delineamento experimental foi inteiramente aleatorizado, com dois tratamentos e doze repetições. Os tratamentos consistiram no tempo das manobras feitas de modo convencional e utilizando-se do sistema de navegação por GPS acoplado num piloto automático. Avaliaram-se o tempo de manobra e o retorno econômico. As manobras realizadas com auxílio do sistema de navegação foram, em média, 49% mais rápidas do que as manobras realizadas de forma convencional. Houve economia de R$ 4,15 por hectare, em áreas com comprimento médio das passadas de 800 metros. No caso de áreas menores, com comprimento de 50 metros, esta economia chegou a R$ 19,90 por hectare. Concluiu-se que o uso de sistema de navegação por satélites, em conjunto com piloto automático, pode gerar economia significativa de tempo e no custo operacional da semeadura.

Information integration and its impacts on logistics performance - Using information technology and systems to facilitate information integration

Fast changing environment sets pressure on firms to share large amount of information with their customers and suppliers. The terms information integration and information sharing are essential for facilitating a smooth flow of information throughout the supply chain, and the terms are used interchangeably in research literature. By integrating and sharing information, firms want to improve their logistics performance. Firms share information with their suppliers and customers by using traditional communication methods (telephone, fax, Email, written and face-to-face contacts) and by using advanced or modern communication methods such as electronic data interchange (EDI), enterprise resource planning (ERP), web-based procurement systems, electronic trading systems and web portals. Adopting new ways of using IT is one important resource for staying competitive on the rapidly changing market (Saeed et al. 2005, 387), and an information system that provides people the information they need for performing their work, will support company performance (Boddy et al. 2005, 26). The purpose of this research has been to test and understand the relationship between information integration with key suppliers and/or customers and a firm’s logistics performance, especially when information technology (IT) and information systems (IS) are used for integrating information. Quantitative and qualitative research methods have been used to perform the research. Special attention has been paid to the scope, level and direction of information integration (Van Donk & van der Vaart 2005a). In addition, the four elements of integration (Jahre & Fabbe-Costes 2008) are closely tied to the frame of reference. The elements are integration of flows, integration of processes and activities, integration of information technologies and systems and integration of actors. The study found that information integration has a low positive relationship to operational performance and a medium positive relationship to strategic performance. The potential performance improvements found in this study vary from efficiency, delivery and quality improvements (operational) to profit, profitability or customer satisfaction improvements (strategic). The results indicate that although information integration has an impact on a firm’s logistics performance, all performance improvements have not been achieved. This study also found that the use of IT and IS have a mediocre positive relationship to information integration. Almost all case companies agreed on that the use of IT and IS could facilitate information integration and improve their logistics performance. The case companies felt that an implementation of a web portal or a data bank would benefit them - enhance their performance and increase information integration.

Äänettömän kevään alkulähteillä

Kirjallisuusarvostelu

Johdatus kosteikkojen biologiaan

Kirjallisuusarvostelu

De Bermudes of Summer Eylanden tot de reystogten afgepeyld door de Engelzen derwaards gedaan

Julkaisussa: De wijd-beroemde voyagien na Oost en West-Indien. Vol I

Teollinen öljyn erotus koalesenssisuodatuksella väliaineessa

Koalesenssi on ilmiö, jossa dispergoidun faasin pisarat pyrkivät muodostamaan suurempia pisaroita kunnes erotettava faasi muodostuu. Koalesenssi tapahtuu kolmessa päävaiheessa, jotka ovat lähestyminen, kiinnittyminen ja irrotus. Lähestymiseen vaikuttavat mekanismit ovat muuan muassa sieppaus, diffuusio, törmäysvaikutus, sedimentaatio, sähköiset repul-siovoimat ja van der Waalsin voimat. Kiinnittymisvaiheessa dispergoidun faasin pisarat syrjäyttävät väliaineen nestekalvon samalla kostuttaen väliaineen pinnan. Irrotusvaiheessa pisaran hydrodynaaminen voima voittaa pisaran ja väliaineen välisen adheesiovoiman. Koalesenssin tehokkuuteen vaikuttavat useat eri parametrit kuten virtausnopeus, pedin ominaisuudet, väliaineen ominaisuudet sekä emulsion ominaisuudet. Nämä kaikki asiat tulee ottaa huomioon koalesenssisuodatuksen suunnittelussa. Koalesenssisuodatus lukeutuu syväsuodatusmenetelmiin, jotka on ollut käytössä jo yli 100 vuotta. Koalesenssisuodatusmenetelmä on tehokas menetelmä pienten pisaroiden erottami-seen. Menetelmää käytetään esimerkiksi öljyisten jätevesien puhdistuksessa. Teollisen öljyn syväsuodatuksen etuihin kuuluu muun muassa sen kompakti koko, alhaisemmat käyt-tökustannukset, korkea erotusaste, kyky erotella pienetkin pisarat sekä helppo operointi, automatisointi ja huolto. Suurin haittapuoli on kuitenkin väliaineen tukkeutuminen, joten prosessi vaatii puhdistuksen tai väliaineen uusimisen. Tämän kandidaatintyön tarkoituksena oli koota kirjallisuustyö öljyn koalesenssisuodatuk-sesta. Työssä kartoitettiin koalesenssisuodatuksen lähtökohdat, teoria, tärkeimmät teolli-suuden sovellukset sekä väliaineet.

Toimijaverkostoteoria ja matkailu

Kirjallisuusarvostelu

La Suede, suivant observations de mess.rs de l'Academie Royale des Sciences, etc. Augmentées de nouveau.

Privilegiomerkintä: Avec privilege.

Development and validation of a genotype 3 recombinant protein-based immunoassay for hepatitis E virus serology in swine

Hepatitis E virus (HEV) is classified within the family Hepeviridae, genus Hepevirus. HEV genotype 3 (Gt3) infections are endemic in pigs in Western Europe and in North and South America and cause zoonotic infections in humans. Several serological assays to detect HEV antibodies in pigs have been developed, at first mainly based on HEV genotype 1 (Gt1) antigens. To develop a sensitive HEV Gt3 ELISA, a recombinant baculovirus expression product of HEV Gt3 open reading frame-2 was produced and coated onto polystyrene ELISA plates. After incubation of porcine sera, bound HEV antibodies were detected with anti-porcine anti-IgG and anti-IgM conjugates. For primary estimation of sensitivity and specificity of the assay, sets of sera were used from pigs experimentally infected with HEV Gt3. For further validation of the assay and to set the cutoff value, a batch of 1100 pig sera was used. All pig sera were tested using the developed HEV Gt3 assay and two other serologic assays based on HEV Gt1 antigens. Since there is no gold standard available for HEV antibody testing, further validation and a definite setting of the cutoff of the developed HEV Gt3 assay were performed using a statistical approach based on Bayes' theorem. The developed and validated HEV antibody assay showed effective detection of HEV-specific antibodies. This assay can contribute to an improved detection of HEV antibodies and enable more reliable estimates of the prevalence of HEV Gt3 in swine in different regions.

EXTRAÇÃO DO COLESTEROL COM MISTURAS DE DIÓXIDO DE CARBONO E ETANO SUPERCRÍTICO

Existem fatores nutricionais e dietéticos, como a ligação comprovada entre o excesso do colesterol no sangue e doenças cardíacas e alguns tipos de câncer, que justificam as pesquisas de desenvolvimento de tecnologias que reduzam o teor de colesterol dos alimentos. Estudos anteriores demonstraram a viabilidade da utilização de CO2 e etano na remoção do colesterol do óleo de manteiga. O colesterol apresenta maior solubilidade no etano que no CO2; porém, o etano é de maior custo. A utilização de misturas CO2/etano, portanto, apresenta-se como uma alternativa atraente, devido à redução dos custos energéticos e econômicos. Utilizando um aparelho experimental de extração a altas pressões, que permite um controle independente de temperatura e pressão, foram determinadas as solubilidades do colesterol em misturas de CO2/etano supercríticos com 8%, 16%, 34%, 76%, 88% e 96,5% de etano, a 328,1 K e pressões de 120 a 190 bar. Os resultados experimentais mostram um aumento da solubilidade com a pressão e a composição de etano na mistura. Para correlacionar os dados experimentais foi usado um modelo termodinâmico que utiliza a equação de Peng-Robinson com as regras de mistura de van der Waals e a regra que considera o parâmetro de interação dependente da densidade, resultando numa equação de quarta ordem. A regra de mistura dependente da densidade se mostrou eficaz na correlação dos dados experimentais.

FRACIONAMENTO DE ÓLEOS DE CITROS UTILIZANDO FLUIDOS SUPERCRÍTICOS

O objetivo deste trabalho é o estudo sobre o fracionamento do óleo de laranja. Neste sentido, o limoneno e o linalol foram considerados os componentes-chaves do óleo de laranja, representando os terpenos e compostos oxigenados, respectivamente. Para modelar os dados de equilíbrio de fases foi usada a equação de estado de Peng-Robinson, juntamente com as regras de mistura de van der Waals, uni e biparamétrica, e de Panagiotopoulos e Reid. O uso desses modelos termodinâmicos permitiu determinar as condições de temperatura e pressão que levaram aos melhores valores do par seletividade-capacidade.

HIGH PRESSURE PHASE EQUILIBRIUM: PREDICTION OF ESSENTIAL OIL SOLUBILITY

This work describes a method to predict the solubility of essential oils in supercritical carbon dioxide. The method is based on the formulation proposed in 1979 by Asselineau, Bogdanic and Vidal. The Peng-Robinson and Soave-Redlich-Kwong cubic equations of state were used with the van der Waals mixing rules with two interaction parameters. Method validation was accomplished calculating orange essential oil solubility in pressurized carbon dioxide. The solubility of orange essential oil in carbon dioxide calculated at 308.15 K for pressures of 50 to 70 bar varied from 1.7± 0.1 to 3.6± 0.1 mg/g. For same the range of conditions, experimental solubility varied from 1.7± 0.1 to 3.6± 0.1 mg/g. Predicted values were not very sensitive to initial oil composition.