385 research outputs found

    Caracterización fisicoquímica y sensorial de mermeladas de frutas de S. Tomé y Príncipe

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    São Tomé and Príncipe has a wide variety of fruit trees, being most of the fruits consumed in fresh. In certain periods of the year, fruits are available at significant amounts; however, it is not common to use the surplus of those fruits. Thus, this excess may be used in the preparation of other fruit based products (ex. jams), in order to increase product diversity and allow the annual consumption of these seasonal fruits. Objetives: To evaluate the characteristics of the fruits of S. Tomé and Príncipe. Methods: Preparation of jams of banana, ambarella, guava (dark and light) and papaya, with two levels of sugar, and perform their physico-chemical characterization (color, pH, moisture and acidity). Furthermore, sensory analysis was also done, through preference and acceptability tests. Results: The jams prepared had different colours, acidity values, and moisture and ash contents, demonstrating the possibility of producing different products by changing the formulation. Regarding jams preference, 60% of the consumers preferred the less sweet in the case of banana and guava (light), whereas, over 67% of the panellists preferred the sweetest ambarella jam. Concerning dark guava and papaya, the percentages were similar for both sugar contents. For all attributes analysed (appearance, colour, taste, acidity, sweetness and global evaluation), most of the panellists liked slightly all jams. Conclusion: The production of jams in S. Tomé and Príncipe presents itself as a promising activity. The quality of the attributes analyzed must be monitored to satisfy consumers.Introdução: São Tomé e Príncipe tem uma grande variedade de árvores frutíferas, sendo a maioria dos frutos consumida em fresco. Em certos períodos do ano, os frutos estão disponíveis em quantidades significativas, não sendo comum usar o excedente. Assim, o excedente de frutos pode ser usado na preparação de outros produtos (ex. doces), para aumentar a diversidade de produtos e permitir o consumo anual desses frutos sazonais. Objetivos: Avaliar as características dos frutos de S. Tomé e Príncipe. Métodos: Preparação de doces de banana, cajá-manga, goiaba (escura e clara) e mamão, com diferentes teores de açúcar, e posteriormente proceder à sua caracterização físico-química (cor, pH, teor de humidade e acidez) e sensorial, através de testes de preferência e aceitabilidade. Resultados: Os doces preparados apresentaram diferentes cores e valores de acidez, humidade e cinza, demonstrando a possibilidade de elaboração de diferentes produtos pela modificação da formulação. Quanto à preferência dos doces, 60% dos consumidores preferiram os menos doces no caso da banana e goiaba (clara), enquanto mais de 67% dos participantes preferiram o doce de cajá- manga mais doce. Quanto à goiaba escura e papaia, as percentagens foram semelhantes para ambos os teores de açúcar. Para todos os atributos analisados (aparência, cor, sabor, acidez, doçura e avaliação global), a maioria dos participantes gostou ligeiramente de todos os doces. Conclusões: A produção de doces em S. Tomé e Príncipe apresenta-se como uma atividade promissora. A qualidade dos atributos analisados deve ser monitorizada, para satisfazer os consumidores.Introducción: S. Tomé y Príncipe tiene una gran variedad de árboles frutales, siendo la mayoría de los frutos comidos en fresco. En ciertos períodos del año, los frutos están disponibles en cantidades significativas, no siendo común el uso de los excedentes. Por lo tanto, este excedente se puede utilizar en la preparación de otros productos y permitir el consumo anual de la fruta de temporada. Objetivos: Evaluar las características de los frutos de Santo Tomé y Príncipe. Métodos: Preparación de mermelada de plátano, caja-mango, guayaba (clara y oscura) y papaya con distintos contenidos de azúcar, y proceder à su caracterización físico-química (color, pH, contenido de humedad y acidez) y sensorial, a través de pruebas de preferencia y aceptabilidad. Resultados: Las mermeladas preparadas tenían diferentes colores y valores de acidez, humedad y cenizas, lo que demuestra la posibilidad de producir diferentes productos. En relación à la preferencia de las mermeladas, 60% de los consumidores prefiere la menos dulce en el caso del plátano y guayaba (clara), mientras más del 67% de los participantes prefiere la mermelada de caja-mango más dulce. En cuanto a la guayaba oscura y papaya, los porcentajes fueron similares para ambos niveles de azúcar. Para todos los atributos analizados (aspecto, color, sabor, acidez, dulzor y evaluación global), la mayoría de los participantes les gustó un poco todas las mermeladas. Conclusións: La producción de mermelades en Santo Tomé y Príncipe se presenta como una actividad prometedora. La calidad de los atributos analizados debe monitorearse para satisfacer a los consumidores.The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) and FEDER under Programme PT2020 for financial support to CIMO (UID/AGR/00690/2013).info:eu-repo/semantics/publishedVersio

    Cardiolipin provides an essential activating platform for caspase-8 on mitochondria

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    Cardiolipin is a mitochondria-specific phospholipid known to be intimately involved with apoptosis. However, the lack of appropriate cellular models to date restricted analysis of its role in cell death. The maturation of cardiolipin requires the transacylase tafazzin, which is mutated in the human disorder Barth syndrome. Using Barth syndrome patient-derived cells and HeLa cells in which tafazzin was knocked down, we show that cardiolipin is required for apoptosis in the type II mitochondria-dependent response to Fas stimulation. Cardiolipin provides an anchor and activating platform for caspase-8 translocation to, and embedding in, the mitochondrial membrane, where it oligomerizes and is further activated, steps that are necessary for an efficient type II apoptotic response

    Gibbs' paradox and black-hole entropy

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    In statistical mechanics Gibbs' paradox is avoided if the particles of a gas are assumed to be indistinguishable. The resulting entropy then agrees with the empirically tested thermodynamic entropy up to a term proportional to the logarithm of the particle number. We discuss here how analogous situations arise in the statistical foundation of black-hole entropy. Depending on the underlying approach to quantum gravity, the fundamental objects to be counted have to be assumed indistinguishable or not in order to arrive at the Bekenstein--Hawking entropy. We also show that the logarithmic corrections to this entropy, including their signs, can be understood along the lines of standard statistical mechanics. We illustrate the general concepts within the area quantization model of Bekenstein and Mukhanov.Comment: Contribution to Mashhoon festschrift, 13 pages, 4 figure

    Relationship between professional motivations and the expectation of staying at the same workplace: a cross-sectional descriptive study with physicians in Portugal

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    There is a global trend related to the migration of health professionals, particularly physicians, to the most densely populated areas. In Portugal, the unequal distribution of medical professionals is justified by the fact that in the most favoured areas, there are more career opportunities, better infrastructures and equipment, better working conditions and supervision, more and better social facilities and better salary. The aim of this work was to identify professional reasons associated with the expectation of staying at the same workplace. It was selected a simple random sample of 594 physicians out of a total of 18,711 registered physicians in Northern Regional Section of the Order of Physicians (NRSOP), Portugal Most physicians would like to stay at the same workplace due to: the prospect of training and working at the current location, the organizational level of the unit, the level of differentiation of the hospital/health centre, the availability to use the state-of-the-art medical and surgical technology, better rewards, the level of work differentiation in the unit/service, the possibility of reconciling public and private practice, good references of the current unit/working group, avoid unit/workgroup with bad references and the prospect of career progression. This study revealed that, for physicians, professional motivations/purposes have an influence on the expectations of staying or not at the same workplace. Therefore, the study recommends that policy makers should prioritize professional reasons when formulating and implementing measures to promote the fixing of medical professionals in order to achieve greater equity in access to health care.This work is supported by: the European Structural and Investment Funds in the FEDER component, through the Operational Competitiveness and Internationalization Programme (COMPETE 2020) [Project No. 006971 (UID/SOC/04011)]; and national funds, through the FCT – Portuguese Foundation for Science and Technology under the project UID/SOC/04011/2013.info:eu-repo/semantics/publishedVersio

    TITAN's Digital RFQ Ion Beam Cooler and Buncher, Operation and Performance

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    We present a description of the Radio Frequency Quadrupole (RFQ) ion trap built as part of the TITAN facility. It consists of a gas-filled, segmented, linear Paul trap and is the first stage of the TITAN setup with the purpose of cooling and bunching radioactive ion beams delivered from ISAC-TRIUMF. This is the first such device to be driven digitally, i.e., using a high voltage (Vpp=400VV_{pp} = \rm{400 \, V}), wide bandwidth (0.2<f<1.2MHz0.2 < f < 1.2 \, \rm{MHz}) square-wave as compared to the typical sinusoidal wave form. Results from the commissioning of the device as well as systematic studies with stable and radioactive ions are presented including efficiency measurements with stable 133^{133}Cs and radioactive 124,126^{124, 126}Cs. A novel and unique mode of operation of this device is also demonstrated where the cooled ion bunches are extracted in reverse mode, i.e., in the same direction as previously injected.Comment: 34 pages, 17 figure

    Time-of-flight and activation experiments on 147Pm and 171Tm for astrophysics

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    The neutron capture cross section of several key unstable isotopes acting as branching points in the s-process are crucial for stellar nucleosynthesis studies, but they are very challenging to measure due to the difficult production of sufficient sample material, the high activity of the resulting samples, and the actual (n,γ) measurement, for which high neutron fluxes and effective background rejection capabilities are required. As part of a new program to measure some of these important branching points, radioactive targets of 147Pm and 171Tm have been produced by irradiation of stable isotopes at the ILL high flux reactor. Neutron capture on 146Nd and 170Er at the reactor was followed by beta decay and the resulting matrix was purified via radiochemical separation at PSI. The radioactive targets have been used for time-of-flight measurements at the CERN n-TOF facility using the 19 and 185 m beam lines during 2014 and 2015. The capture cascades were detected using a set of four C6D6 scintillators, allowing to observe the associated neutron capture resonances. The results presented in this work are the first ever determination of the resonance capture cross section of 147Pm and 171Tm. Activation experiments on the same 147Pm and 171Tm targets with a high-intensity 30 keV quasi-Maxwellian flux of neutrons will be performed using the SARAF accelerator and the Liquid-Lithium Target (LiLiT) in order to extract the corresponding Maxwellian Average Cross Section (MACS). The status of these experiments and preliminary results will be presented and discussed as well

    Characterization of the n-TOF EAR-2 neutron beam

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    The experimental area 2 (EAR-2) at CERNs neutron time-of-flight facility (n-TOF), which is operational since 2014, is designed and built as a short-distance complement to the experimental area 1 (EAR-1). The Parallel Plate Avalanche Counter (PPAC) monitor experiment was performed to characterize the beam prole and the shape of the neutron 'ux at EAR-2. The prompt γ-flash which is used for calibrating the time-of-flight at EAR-1 is not seen by PPAC at EAR-2, shedding light on the physical origin of this γ-flash

    Measurement of the 240Pu(n,f) cross-section at the CERN n-TOF facility : First results from experimental area II (EAR-2)

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    The accurate knowledge of the neutron-induced fission cross-sections of actinides and other isotopes involved in the nuclear fuel cycle is essential for the design of advanced nuclear systems, such as Generation-IV nuclear reactors. Such experimental data can also provide the necessary feedback for the adjustment of nuclear model parameters used in the evaluation process, resulting in the further development of nuclear fission models. In the present work, the 240Pu(n,f) cross-section was measured at CERN's n-TOF facility relative to the well-known 235U(n,f) cross section, over a wide range of neutron energies, from meV to almost MeV, using the time-of-flight technique and a set-up based on Micromegas detectors. This measurement was the first experiment to be performed at n-TOF's new experimental area (EAR-2), which offers a significantly higher neutron flux compared to the already existing experimental area (EAR-1). Preliminary results as well as the experimental procedure, including a description of the facility and the data handling and analysis, are presented

    New measurement of the 242Pu(n,γ) cross section at n-TOF-EAR1 for MOX fuels : Preliminary results in the RRR

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    The spent fuel of current nuclear reactors contains fissile plutonium isotopes that can be combined with 238U to make mixed oxide (MOX) fuel. In this way the Pu from spent fuel is used in a new reactor cycle, contributing to the long-term sustainability of nuclear energy. The use of MOX fuels in thermal and fast reactors requires accurate capture and fission cross sections. For the particular case of 242Pu, the previous neutron capture cross section measurements were made in the 70's, providing an uncertainty of about 35% in the keV region. In this context, the Nuclear Energy Agency recommends in its "High Priority Request List" and its report WPEC-26 that the capture cross section of 242Pu should be measured with an accuracy of at least 7-12% in the neutron energy range between 500 eV and 500 keV. This work presents a brief description of the measurement performed at n-TOF-EAR1, the data reduction process and the first ToF capture measurement on this isotope in the last 40 years, providing preliminary individual resonance parameters beyond the current energy limits in the evaluations, as well as a preliminary set of average resonance parameters
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