634 research outputs found
Integrated reporting an exploratory study on the motivations and obstacles in the adoption of a new information reporting system
This study explores the motives for voluntary
adoption and reasons for non-adoption of integrated reporting by
Portuguese listed companies. For this purpose, a questionnaire
survey was addressed to adopters and non-adopters of integrated
reporting. The results reveal motivations for integrated reporting
associated with external pressures and reporting trends of other
companies. The cost of implementing this new reporting system
seems to be the main reason why few companies do it yet. The
preparation of sustainability information in accordance with
internationally recognized frameworks seems to be the current
priority of companies and an intermediate step between
traditional financial reporting and integrated reporting.info:eu-repo/semantics/publishedVersio
Distribution of 1.68 eV emission from diamond films
Free-standing polycrystalline chemical vapor deposition diamond films grown on a silicon wafer, with electrical behavior similar to values currently mentioned in the literature, present microheterogeneity. A detailed analysis by micro Raman shows how the diamond and nondiamond phases are distributed within the film and also the distribution of the silicon related luminescence. This luminescence is discussed in terms of two emitting centers close in energy. Absolute intensity of the diamond peak is not correlated with the good quality of the film as assessed by the Raman linewidth and ratio of this line to the nondiamond Raman line
Structural and optical properties of Zn0.9 Mn0.1 O/ZnO core-shell nanowires designed by pulsed laser deposition
Partilhar documento na coleção da comunidade Laboratório Associado I3NCore-shell ZnO/ZnMnO nanowires on a-Al2O3 and GaN (buffer layer)/Si (111) substrates were fabricated by pulsed laser deposition using a Au catalyst. Two ZnO targets with a Mn content of 10% were sintered at 1150 and 550 °C in order to achieve the domination in them of paramagnetic MnO2 and ferromagnetic Mn2O3 phases, respectively. Cluster mechanism of laser ablation as a source of possible incorporation of secondary phases to the wire shell is discussed. Raman spectroscopy under excitation by an Ar+ laser revealed a broad peak related to the Mn-induced disorder and a redshift in the A1-LO phonon. Resonant Raman measurements revealed an increase in the multiphonon scattering caused by disorder in ZnO upon doping by Mn. Besides the UV emission, a vibronic green emission band assisted by a ∼ 71 meV LO phonon is also observed in the photoluminescence spectra. Core-shell structures with smooth shells show a high exciton to green band intensity ratio ( ∼ 10) even at room temperature.
© 2009 American Institute of PhysicsSANDiE Network of Excellence of the EUFCT-PTDC/FIS/72843/200
Morphology and structure of acorn starches isolated by enzymatic and alkaline methods
Research articleMorphology and structure of starch from fruits
of two acorns species, Quercus rotundifolia Lam. (QR) and
Quercus suber Lam. (QS), isolated by enzymatic (ENZ)
and alkaline (A3S) methods were studied. Acorn starches
granules presented a round and oval shape, consisting of
medium/small granules, with a mean granule size ranging
between 9 and 13 μm. Isolated acorn starches appear
as light grayish-brown in naked eye, with high values
of L* for starches isolated by the ENZ method, and
QR starches were duller than QS. No differences were
observed for all the samples in FTIR spectra results.
Acorn starches showed a C-type pattern, with a relative
crystallinity between 43.1 and 46.6%. The 13C CP/MAS
NMR spectra are different for the used isolation methods
but are similar for both acorn species. However, acornisolated
starches presented a predominant A-type allomorph
packing type, and the A3S starches showed a
higher degree of crystalline material. Those differences
in the structure of acorn starches would be helpful to
better understand the relationships among structure and
functional properties for a possible potential industrial
application of chestnut starchesinfo:eu-repo/semantics/publishedVersio
Study about attitudes, perceptions and knowledge regarding edible insects in Portugal
Os insetos têm sido apontados como uma fonte alternativa e mais sustentável de proteÃna animal, que pode ajudar a alimentar a crescente população mundial. Devido à menor pegada e impacto ambiental, a substituição parcial da proteÃna animal por insetos pode contribuir para a preservação do meio ambiente e dos ecossistemas naturais. No entanto, o consumo de insetos comestÃveis, embora culturalmente aceite em algumas comunidades, não é prontamente aceite noutras. Assim, este trabalho investigou o conhecimento, atitudes, hábitos de consumo e grau de aceitabilidade de insetos ou produtos derivados entre consumidores portugueses. Este estudo foi baseado numa pesquisa por questionário, realizada numa amostra de 213
participantes.
Os resultados mostraram que os portugueses tendem a ter perceções corretas sobre as questões de sustentabilidade relacionadas com a utilização de insetos como alternativa a carnes convencionais. No entanto, o grau de conhecimento sobre o valor nutritivo dos insetos e possÃveis efeitos na saúde é baixo. Entre os indivÃduos pesquisados, apenas uma pequena percentagem indicou já ter comido insetos, consumidos maioritariamente no estrangeiro, por iniciativa própria, seja em restaurantes ou em festas/eventos sociais. Não surpreendentemente, observou-se que há uma maior relutância em consumir insetos inteiros do que em ingeri-los como ingredientes utilizados em preparações alimentares. Assim, em conclusão, a investigação revelou que os portugueses ainda apresentam alguma resistência para aderir ao consumo de insetos como
alternativa a outros produtos cárneos, mas não se descarta que o mercado de produtos à base de insetos possa ser uma forma de ultrapassar a neofobia associada a este tipo de alimentos num paÃs tradicionalmente não comedor de insetos.Insects have been pointed out as an alternative and more sustainable source of animal protein that might help feed the growing world population. Because of the lower footprint and environmental impact, replacing partly the animal protein by insects can contribute to the preservation of the environment and natural ecosystems. However, the consumption of edible insects, although culturally accepted for some communities, is not readily accepted for others. Hence this work investigated the knowledge, attitudes, consumption habits, and degree of acceptability of edible insects or derived products among Portuguese consumers. This study was based on a questionnaire survey undertaken on a sample of 213 participants. The results showed that the Portuguese tend to have correct perceptions about the sustainability issues related to the utilization of edible insects as an alternative to conventional meats. Nevertheless, the degree of knowledge about the nutritive value of
insects and possible health effects is low. Among the individuals surveyed, only a small percentage indicated they had already eaten insects, consumed mostly abroad, by self-initiative, and either in restaurants or at parties/social events. Not surprisingly, it was observed that there is a higher reluctance to consume whole insects than to ingest them as ingredients used in food preparations. So, in conclusion, the research revealed that the Portuguese still present some resistance to adhere to the consumption of insects as an alternative to other meat products, but it is not discarded that the market of insect based products can be a way to surpass the neophobia associated with this type of food on a traditionally non-insect-eating country.info:eu-repo/semantics/publishedVersio
Study about attitudes, perceptions and knowledge regardind edible insects in Portugal
Os insetos têm sido apontados como uma fonte alternativa e mais sustentável de proteÃna animal, que pode ajudar a alimentar a crescente população mundial. Devido à menor pegada e impacto ambiental, a substituição parcial da proteÃna animal por
insetos pode contribuir para a preservação do meio ambiente e dos ecossistemas naturais. No entanto, o consumo de insetos comestÃveis, embora culturalmente aceite em algumas comunidades, não é prontamente aceite noutras. Assim, este trabalho
investigou o conhecimento, atitudes, hábitos de consumo e grau de aceitabilidade de insetos ou produtos derivados entre consumidores portugueses. Este estudo foi baseado numa pesquisa por questionário, realizada numa amostra de 213
participantes.
Os resultados mostraram que os portugueses tendem a ter perceções corretas sobre as questões de sustentabilidade relacionadas com a utilização de insetos como alternativa a carnes convencionais. No entanto, o grau de conhecimento sobre o valor nutritivo dos insetos e possÃveis efeitos na saúde é baixo. Entre os indivÃduos pesquisados, apenas uma pequena percentagem indicou já ter comido insetos, consumidos maioritariamente no estrangeiro, por iniciativa própria, seja em restaurantes ou em festas/eventos sociais. Não surpreendentemente, observou-se que há uma maior relutância em consumir
insetos inteiros do que em ingeri-los como ingredientes utilizados em preparações alimentares. Assim, em conclusão, a investigação revelou que os portugueses ainda apresentam alguma resistência para aderir ao consumo de insetos como
alternativa a outros produtos cárneos, mas não se descarta que o mercado de produtos à base de insetos possa ser uma forma de ultrapassar a neofobia associada a este tipo de alimentos num paÃs tradicionalmente não comedor de insetos.info:eu-repo/semantics/publishedVersio
Surface boundary layer characteristics over caatinga vegetation in tropical semiarid region of N-E Brazil
Some characteristic features of the atmospheric surface layer over
a tropical semiarid station Petrolina (9.9â—¦S, 40.22â—¦W, 365.5 m) in N-E Brazil, are
investigated, using data collected from a micrometeorological tower of 9 m height.
This study utilizes the wind, temperature, humidity and carbon dioxide (CO2) data
obtained for the month of July 2004. The diurnal variation of mean parameters
such as temperature, relative humidity, wind speed and CO2 are studied. Turbulent
statistics are computed using the eddy correlation technique, and are studied under
the framework of Monin-Obukhov similarity theory with results compared with other
experimental studies reported in the literature
Honey Bee (Apis mellifera L.) Broods: Composition, Technology and Gastronomic Applicability
Honey bee broods (larvae and pupae) can be consumed as human food, offering a rich nutritional value. Therefore, the objective of this work was to present an overview of the nutritional value of the honey bee brood and its gastronomic potential. The results indicated that honey bee broods are rich in protein (including essential amino acids), fat (essentially saturated and monounsaturated fatty acids), carbohydrates, vitamin C and those of the B complex, and minerals such as potassium, magnesium, calcium, and phosphorous. The results further highlight some variability according to the stage of development, with increasing content of fat and protein and decreasing carbohydrates from the larval to the pupal stages. The production of the honey bee brood in the hive, as well as its removal, can impact the wellbeing of the hive. This limits the production potential of the brood aimed at application for gastronomic purposes. The consumption and purchase of honey bee broods as food may be accessible in specialised markets where, for example, ethnic communities consume this type of food. However, in some markets, insects or products produced from insects are not readily accepted because of neophobia and disgust. The role of culinary chefs allied to traditional ways of preparing culinary dishes that include honey bee broods are relevant to motivate more people in western societies to consume of these types of food products.info:eu-repo/semantics/publishedVersio
Honey bee (Apis mellifera L.) broods: composition, technology and gastronomic applicability
Honey bee broods (larvae and pupae) can be consumed as human food, offering a rich
nutritional value. Therefore, the objective of this work was to present an overview of the nutritional value of the honey bee brood and its gastronomic potential. The results indicated that honey bee broods are rich in protein (including essential amino acids), fat (essentially saturated and monounsaturated fatty acids), carbohydrates, vitamin C and those of the B complex, and minerals such as potassium, magnesium, calcium, and phosphorous. The results further highlight some variability
according to the stage of development, with increasing content of fat and protein and decreasing carbohydrates from the larval to the pupal stages. The production of the honey bee brood in the hive, as well as its removal, can impact the wellbeing of the hive. This limits the production potential of the brood aimed at application for gastronomic purposes. The consumption and purchase of honey bee broods as food may be accessible in specialised markets where, for example, ethnic communities consume this type of food. However, in some markets, insects or products produced from insects are not readily accepted because of neophobia and disgust. The role of culinary chefs allied
to traditional ways of preparing culinary dishes that include honey bee broods are relevant to motivate more people in western societies to consume of these types of food products.info:eu-repo/semantics/publishedVersio
Sustainable extraction of biocompounds from the green seaweed ulvarigida using ohmic heating
The development of new green and sustainable extraction technologies with low environmental impact and providing
high nutritional functionalities, safety and applicability, has become relevant. Ohmic heating (OH) has emerged as a novel
electric-based technology which allows high heating rates, higher selectivity of interest compounds, less energy and
solvent consumption and energetically more efficient.[1,2] Ulva rigida is a green seaweed with high exploitation potential
for commercial application. Its major compound of interest is ulvan, a sulfated polysaccharide present in the cell wall that
has a wide range of possible applications in nutraceuticals, functional foods, agriculture and biomaterials.[3] The aim of this
work was to access the feasibility of OH assisted extraction as an alternative extraction technology in the recovery of
biocompounds (e.g.: polysaccharides, proteins, phenolic compounds and pigments) from Ulva rigida using different ratios
of water/ethanol in different times of extraction. Extractions were made using a solid:solvent ratio of 1:30 and
water/ethanol mixtures ranging from 0 to 75 % ethanol to extract different seaweeds fractions. The extractions were
performed at 82 °C during 1 h, 2 h and 3 h, and the frequency was set at 25 kHz. Control extractions were made using a
water bath (conventional extraction) with the same conditions, but without the presence of an electric field. Different
parameters were assessed including extraction yield, lipids, ashes, moisture, total polysaccharides, protein, total phenolic
compounds and pigments (chlorophylls and carotenoids) content, antioxidant activity and gelling ability. Higher
extraction and ulvan-fraction yields, as well as total polysaccharides were obtained after 3 h of extraction for aqueous
extracts. Total phenolic compounds, proteins and pigments content and antioxidant activity were higher for mixtures with
higher amounts of ethanol. For antioxidant activity and total phenolic compounds, the 50:50 H2O/EtOH mixture under OH
proved to be more efficient, with an increase up to 10 %, when compared to conventional extraction. Also, for pigments
and protein content, the 25:75 H2O/EtOH mixture allowed promising results for 1 h of extraction. Gelling ability was
identical in all produced extracts. As conclusion, these results showed that OH is a good alternative for a low cost and
environmental-friendly extraction technology, for the recovery of bioactive compounds from green seaweeds.info:eu-repo/semantics/publishedVersio
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