Electrical transport properties of CuS single crystals

Electrical resistivity, transverse magnetoresistance and thermoelectric power measurements were performed on CuS high quality single crystals in the range 1.2-300 K and under fields of up to 16 T. The zero field resistivity data are well described below 55 K by a quasi-2D model, consistent with a carrier confinement at lower temperatures, before the transition to the superconducting state. The transverse magnetoresistance develops mainly below 30 K and attains values as large as 470% for a 16 T field at 5 K, this behaviour being ascribed to a band effect mechanism, with a possible magnetic field induced DOS change at the Fermi level. The transverse magnetoresistance shows no signs of saturation, following a power law with field Delta rho/rho(0) proportional to H(1.4), suggesting the existence of open orbits for carriers at the Fermi surface. The thermoelectric power shows an unusual temperature dependence, probably as a result of the complex band structure of CuS

Social Networks on the Web in Real Estates in Portugal

Abstract This article aims to analyze different types of Social Networks, its purpose, success and evolution, and also its usefulness for people and businesses, in particular in Real Estate mediation in Portugal. This article includes some research related to the use of Social Networks and relationships with Real Estate. First it is analysed, structured and classified the Social Networks and issues related to investment and relations with Marketing, and it is also analysed the Real Estate business. Then it is presented some statistics based on data according to Social Networking use in Real Estate companies in Portugal and in particular, the adoption of Facebook. Finally, we present conclusions of this study and point out the main limitations of this research and recommendations for future studies. According to statistics made to Real Estate companies in Portugal, in a universe of 3231, and given a sample of about 500 companies in the business of Real Estate, 15% have their own sites and in these, enrolment is up 12% on Facebook, 4% on Twitter, 1% on LinkedIn, and no more than 1% on YouTube. Adding and adapting technologies and new trends like Social Networks using the Internet, we can expect a better understanding of consumers and new ways of doing business and new business opportunities. There are few articles referring to Social Networks and Real Estate and considering Portugal, studies are rare. This kind of researches should be more frequent and compared, as possible, with other countries and other situations. Paper type -Research paper

Augmented reality and user experience (UX) in the dissemination of digital content from Portuguese museums

No presente artigo salienta-se a importância que os museus atribuem às novas tecnologias e em melhorar a Experiência dos Utilizadores (UX) recorrendo à tecnologia de Realidade Aumentada na divulgação de conteúdos digitais, entre o espaço físico e digital do museu. Numa primeira fase procurou-se entender a perceção e interação dos utilizadores através de indicadores de análise de conteúdo, pela plataforma digital Instagram, associando três empresas de Realidade Aumentada. Numa segunda fase, procurando estabelecer ligação à vertente de negócio, à adoção e aceitação tecnológica, realizaram-se entrevistas aos departamentos de comunicação de três Museus Portugueses De uma forma geral, foi possível reconhecer a importância e o potencial de crescimento em associar a tecnologia de Realidade Aumentada na divulgação de conteúdos digitais, seja de acordo com o panorama cultural, histórico ou turístico em Portugal. Os resultados obtidos são pressupostos de aplicabilidade nos museus, associados ao estudo de caso: a Startup Nimest.info:eu-repo/semantics/publishedVersio

Ventilation and deodorization system optimization of a wastewater treatment plant

Quality of life is entirely linked to air quality around us, whether inside or outside a building. Therefore, it is not surprising that the owners and occupants of certain spaces pay attention to the air quality, especially when they work or are close to a wastewater treatment plant. The aims of this work are to diagnose the existing situation in ventilation and deodorization system of covered wastewater treatment plant and to suggest changes to improve indoor air quality and make the operation of this system more reliable and economical. The ventilation system, consisting of 10 air handling units, supply 230.000 m3/h, where some ventilation lines have 250 m. The system’s optimization solution, as well as the two new centrifugal fans implementation, with speed variation, allow a reduction in the total fans power to 60 kW and increase the energy efficiency in 60 %

Quality control of oils as a key element of HACCP systems in the catering industry

Food safety is a major issue for the consumer who has started to understand the health and economical consequences of food borne disorders. Although each player from the food chain has responsibility, the catering industry represents the last line of defense before food reaches the consumer. The use of fried foods is very common but, unfortunately, undesirable substances such as polar compounds are formed during the frying process and continuous ingestion of these compounds can induce diseases, including e.g. stomach and lung cancer. Several legislations worldwide prohibit the consumption of foodstuffs fried in fats containing more than 25% of polar compounds. The implementation of HACCP systems is mandatory and the control of oils quality is considered to be a Critical Control Point (CCP). The measurement of polar compounds concentration is necessary to assure that the CCP is under control and, being so, the establishment of monitoring procedures that can return data in real time is crucial. The official (ISO) method for determining the polar compounds concentration is expensive and time consuming and cannot be used for real time monitoring of a CCP. Oleo Test® is a colorimetric test having a 5 color scale to determine the interval of polar compounds concentration present in the sample. The results, using samples obtained from restaurants or lab samples from different types of oils, were compared with the ones from ISO method in order to test reliability and reproducibility of Oleo Test®. Over 95% of the results retrieved by the kit (given as color intervals) were in accordance with the ISO results (see figure). It can be clearly concluded that Oleo Test® can be an advantageous replacement for the ISO method in controlling this CCP in the catering industry, thus assuring food safety.info:eu-repo/semantics/publishedVersio

The use of moderate electric fields (MEF) to increase the biomass production and reduce the lag phase of a fermentative process

The use of moderate electric fields to assist fermentations has not been exhaustively investigated but some results on this subject point out to promising results either on enhancing metabolite production or on lag phase reduction. The use of MEF in recombinant strains has never been studied and the increased industrial use of modified strains to produce medicines or food ingredients makes this a relevant issue. The possibility of further optimization of the fermentative processes in place or new industrial applications using this technology opens a wide range of economical and social advantages. The main objectives of this work were to address the effects of MEF on the lag phase and biomass yield and consequently on primary metabolite production, namely -galactosidase on a recombinant Saccharomyces cerevisiae strain expressing lacA gene (coding for -galactosidase) of Aspergillus niger> under ADHI promotor and terminator. This strain has been selected due to its high ethanol and -galactosidase productivities and also because continuous fermentative processes can be carried out due to its excellent flocculation capability. Batch culture experiments were performed at optimal growth conditions in synthetic medium under aerobic conditions. Two stainless steel electrodes were placed symmetrically inside the bioreactor and the electric field was varied from 0 to 2 V.cm-1. The biomass production expressed in g.L-1 increased linearly with the applied electric field in the range of 0 to 2.0 V.cm-1 Lag phase almost disappeared when using higher voltages. Improved transport through the cell flocs and improved transport through the cell membrane due to pore formation or activation of transport proteins may explain this behaviour but this is yet to be proved. In conclusion, the use of MEF is a new parameter that can be manipulated to optimize fermentative processes namely the ones in which the biomass production is an important parameter (e.g. SCP, antibiotics).info:eu-repo/semantics/publishedVersio

Formation of oriented nickel aggregates in rutile single crystals by Ni implantation

The magnetic and electrical properties of Ni implanted single crystalline TiO2 rutile were studied for nominal implanted fluences between 0.5 x 10(17) cm(-2) and 2.0 x 10(17) cm(-2) with 150 keV energy, corresponding to maximum atomic concentrations between 9 at% and 27 at% at 65 nm depth, in order to study the formation of metallic oriented aggregates. The results indicate that the as implanted crystals exhibit superparamagnetic behavior for the two higher fluences, which is attributed to the formation of nanosized nickel clusters with an average size related with the implanted concentration, while only paramagnetic behavior is observed for the lowest fluence. Annealing at 1073 K induces the aggregation of the implanted nickel and enhances the magnetization in all samples. The associated anisotropic behavior indicates preferred orientations of the nickel aggregates in the rutile lattice consistent with Rutherford backscattering spectrometry-channelling results. Electrical conductivity displays anisotropic behavior but no magnetoresistive effects were detected. (C) 2013 Elsevier B.V. All rights reserved

Relationship between acrylamide formation and quality of frying oil during processing of French fries

Thermal treatments such as frying and baking are fundamental to obtain specific sensorial characteristics such as color and flavor in foods. Thermal treatments may also induce the formation of health-promoting components, such as antioxidants and antimicrobial agents, or potentially harmful compounds in foods. Therefore, the knowledge of chemical reactions occurring in foods is of extreme importance from a food safety point of view. The presence of acrylamide in thermally processed foods has been considered as an important food-related crisis by international authorities. It is well-known that temperature plays an important role in acrylamide formation especially for shorter heating times as in frying of potato chips; lowering the frying temperature may significantly reduce the amount of acrylamide formed. The aim of the present work was to determine the relation of acrylamide formation and the quality of oil (in terms of total polar materials-TPM) during French fries processing. Process temperature ranged from 170 to 200ºC and TPM of frying oils ranged from 5 to 15%. Acrylamide was quantified by HPLC and TPM were assessed according to ISO 8420:2002. For all tested temperatures the concentration of acrylamide increased with the raise of the frying temperature and also with the increase of TPM present in oil, except for the 200ºC assay in which the acrylamide formed seems to remain constant for all the values of TPM tested. The results seem to reinforce the importance of controlling the quality of frying fats in terms of TPM, which has now been shown to enhance acrylamide formation thus representing a supplementary food safety risk.info:eu-repo/semantics/publishedVersio

Comparison of the Thermal Inactivation Kinetics of Byssochlamys fulva and Three Enzymes used as TTIs for Various Food Processes under Conventional and Ohmic Heating

Ohmic heating technology has regained interest for aseptic food processing of highly viscous fluids (e.g. fruit pulps and purees) or particulate fluids. The industrial application of this technology is fully dependent on its validation with experimental data in order to evaluate the effects of the electric field on microorganisms, enzymes and biological tissues. This work aims at determining the effect of an electric field on the thermal inactivation kinetics of a highly heat resistant microorganism (Byssochlamys fulva - an ascospore producer thermophilic fungus) and also on the inactivation kinetics of several enzymes used as time-temperature integrators (TTIs) (lipoxygenase - LOX, polyphenoloxidase - PPO and alkali phosphatase - PA). For both ohmic and conventional processes, and for similar samples thermal histories, the corresponding D-values were determined, leading to the calculation of the z-value, the activation energy (Ea) and the pre-exponential factor (k) of Arrhenius equation. B. fulva death kinetics were determined in an industrial strawberry pulp (14.5 ºBrix, pH=4.0); PA inactivation was determined in raw milk and PPO and LOX inactivation was determined in buffer. In all cases first order inactivation kinetics were observed. The experimental D values for B. fulva obtained under ohmic heating (Doh) conditions were half the ones obtained for conventional heating (Dconv) (T=85 ºC, Dconv=7.23; Doh=3.27). Similar results were found for PPO: ohmic D values were three times lower than those for conventional heating (T=75 ºC, Dconv=61.61; Doh=19.37). For LOX, D values were lower for ohmic heating but z and Ea values were slightly higher when compared to conventional heating. For PA no significant differences were found between the two heating processes in terms of D, z or Ea values. The electric field reduces the D values for both enzymes and microorganisms but z and Ea values are not greatly affected by the electric field. The obtained kinetics will be used to validate thermal processing in a pilot scale continuous ohmic heater.info:eu-repo/semantics/publishedVersio

Economic analysis of family trout farming in Southern Brazil.

Thus, the objective of the present study was to analyze the economic feasibility of trout farming on family farms in the Serra Catarinense region, SC, Brazil, comparing two profiles of farming by characterizing their different scales of production