609 research outputs found

    Reviving earthen architecture in Palestine: The added significances of the building sustainability and an opportunity for the future

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    Several attempts have emerged recently in Palestine aiming to find an economical-environmental alternative building material beside the widely-used natural stone as a main building material, due to some factors related to the cost and the negative effects of stone mining areas on the local environment. Similar attempts had a certain response to the peculiar social needs and economic situation there. The efforts led to revive earthen architecture on organizational and individual levels, producing a certain number of earthen buildings in the last few years. In order to evaluate the appropriateness of earth as an alternative raw material in Palestine, the paper outlines the general advantages and limits of this building material, in comparison with the current prevalent way of construction and discussing the different needs in rural and in urban contexts, taking into account the housing emergency due to the successive military attacks there. As in other realities, also in Palestine a radical transformation has occurred in the traditional built environment that is possible to be assessed by a multi-scale analysis, in the urban fabric as well as in the minor building components. In addition, the critical condition as a consequence of the well-known peculiar political situation, distinguishes the social housing situation in Palestine, increasing the humanitarian aspects in the wider scenario of the social, economic, and environmental aspects. The aims of the building sustainability, mainly focused on the energy efficiency and environmental impacts in the European Union, but in a context such as Palestine, it acquires an added significance. The earth architecture could assume the role of a social inclusion tool, thanks to its inherent meanings that overstep the material and technical dimension, to the human factor being the main leverage of innovation. The paper will describe some strategic and integrated proposals aiming to face the limits of earthen architecture, discussing if and how the revival of this ancestral building material can help in gaining a useful innovation for the future, in Palestine as well as in the most parts of the Mediterranean region

    Assessment of indoor radon-222 concentrations in the vicinity of Manyoni uranium deposit, Singida

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    This study aimed to assess indoor radon concentrations in the vicinity of the Manyoni Uranium Deposit in Singida. The concentrations were measured for two months in 32 houses in the vicinity of Manyoni Uranium Deposit and 9 houses at Manyoni town using a portable radon gas monitor (Alpha –GUARDTM). The radon concentrations ranged from 27±3 to 518±28 Bq/m3with the overall mean of 166±12 Bq/m3 which is above recommended values of 100 Bq/m3 and 148 Bq/m3 set by WHO (World Health Organization) and EPA (Environmental Protection Agency's), respectively. The overall mean of indoor radon concentrations from each village were Kipondoda (169±13 Bq/m3), Muhalala (177±16 Bq/m3), Mwanzi, (287±13 Bq/m3), Mitoo (325±21 Bq/m3) and Majengo (377±23 Bq/m3) which exceed the limit set by WHO (World Health Organization) and EPA (Environmental Protection Agency). The value of 325±21 Bq/m3 and 377±23 Bq/m3 from Mitoo and Majengo respectively, exceed the limit of 300 Bq/m3 recommended by ICRP (International Commission on Radiation Protection). Thus there is a non-negligible probability of incurring stochastic effects for people living in the vicinity of Manyoni Uranium mine. It is recommended that human activities should be controlled   near the uranium deposits and dwelings should be well ventilated.Keywords: Indoor radon, Concentrations, Cancer, Manyoni uranium deposit, Alpha –GUAR

    Properties of galaxy halos in Clusters and Voids

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    We use the results of a high resolution N-body simulation to investigate the role of the environment on the formation and evolution of galaxy-sized halos. Starting from a set of constrained initial conditions, we have produced a final configuration hosting a double cluster in one octant and a large void extending over two octants of the simulation box. We present results for two statistics: the relationship between 1-D velocity dispersion and mass and the probability distribution of the spin parameter P(λ)P(\lambda). The \svm relationship is well reproduced by the Truncated Isothermal Sphere (TIS) model introduced by Shapiro et al. (1999), although the slope is different from the original prediction. A series of \svm relationships for different values of the anisotropy parameter β\beta, obtained using the theoretical predictions by Lokas and Mamon (2001) for NFW density profiles are found to be only marginally consistent with the data. Using some properties of the equilibrium TIS models, we construct subsamples of {\em fiducial} equilibrium TIS halos from each of the three subregions, and we study their properties. For these halos, we do find an environmental dependence of their properties, in particular of the spin parameter distribution P(λ)P(\lambda). We study in more detail the TIS model, and we find new relationships between the truncation radius and other structural parameters. No gravitationally bound halo is found having a radius larger than the critical value for gravithermal instability for TIS halos (\rt ≥34.2r0\ge 34.2 r_{0}, where r0r_{0} is the core radius of the TIS solution). We do however find a dependence of this relationship on the environment, like for the P(λ)P(\lambda) statistics. These facts hint at a possible r\^{o}le of tidal fields at determining the statistical properties of halos.Comment: 12 pages, 14 figures. Accepted by MNRAS. Adopted an improved algorithm for halo finding and added a comparison with NFW model

    Application of Encapsulation Technology: In Vitro Screening of Two Ficus carica L. Genotypes under Different NaCl Concentrations

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    Salinity stress represents an increasing issue for agriculture and has a great negative impact on plant growth and crop production. The selection of genotypes able to tolerate salt stress could be a suitable solution to overcome the problem. In this context, in vitro cultures can represent a tool for identifying the NaCl tolerant genotypes and quickly producing large populations of them. The possibility of exerting selection for tolerance to NaCl by using encapsulation technology was investigated in two genotypes of fig: 'Houmairi' and 'Palazzo'. The effects of five concentrations of NaCl (0, 50, 100, 150 and 200 mM) added to the artificial endosperm were tested on the conversion of synthetic seeds and on the growth of derived shoots/plantlets. Moreover, proline (Pro) and malondialdehyde (MDA), the enzymatic activities of catalase (CAT), guaiacol peroxidase (POD), and EL (Electrolytic Leakage), as well as the chlorophyll content, flavanols, anthocyanins, and Nitrogen Balance Index (NBI) were determined on shoots/plantlet. The obtained results clearly showed that 'Houmairi' and 'Palazzo' could tolerate salt stress, although a strong difference was found depending on each specific physiological pathway. Indeed, 'Houmairi' was revealed to be more tolerant than 'Palazzo', with different response mechanisms to salt stress. The use of encapsulated vitro-derived explants proved to be a useful method to validate the selection of genotypes tolerant to salinity stress. Further investigation in the field must validate and confirm the legitimacy of the approach

    Monitoring the Shelf-Life of Minimally Processed Fresh-Cut Apple Slices By Physical–Chemical Analysis and Electronic Nose

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    Fresh-cut apples, in slices or in cubes, are minimally processed products, which are currently collecting a great interest by fruit marketers for their promising diffusion. Their shelf life, from a microbiological point of view, has been fixed about 2 or 3 weeks under refrigeration. However in a few days they undergo biochemical degradations with production of off-flavors and texture breakdown. In this work, the change of aromatic fingerprint of apple slices packaged in air and in a modified atmosphere (with 100% N2) and stored at 4°C was measured, by using a commercial electronic nose. The obtained data were also compared with sensory evaluation of judge’s panel. Moreover, quality parameters such as total acidity, total soluble solids and firmness were determined at different storage times (0, 4, 8 and 12 days). The data show that the electronic nose is able to discriminate between the two different storage conditions applied: the multivariate analysis, Principal Component Analysis, presents clearly differences among the four sampling times when the apple slices are stored in air and in N2. Our results indicate that the electronic nose can be considered a valid supplementary tool to human sensory panel assessment especially in food quality safety and control and it can be a simple, objective and rapid method to control the food quality during the storage

    Somatic embryogenesis in Abies nebrodensis, an endangered Sicilian fir

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    Somatic embryogenesis, as a promising biotechnological tool for many conifer trees, has never been applied for the Abies nebrodensis species. Although all the encouraging results previously obtained by the EU LIFE (European LIFE program) funded projects in over ten years, the critically endangered Sicilian fr remains alarmingly close to extinction. In this study, we reported the first protocol of somatic embryogenesis obtained from mature zygotic embryos of the Abies nebrodensis. Seeds from Abies adult trees with specifc identifcation numbers (IN) were collected and full seeds were identifed by X-ray. Diferent experiments were carried out for callus initiation, from both zygotic immature and mature embryos, testing diferent culture media. The immature embryos did not give embryogenic tissue (ET). Embryogenic callus (EC) was successfully induced from mature embryos with variable frequencies (0–40%). Schenk and Hilderbrandt (SH) was the most suitable initiation medium where the obtained callus initiation rate reached up to 40% for IN7 (frst experiment). 6-benzylaminopurine (BAP) showed to be essential to induce EC (second experiment). IN8 presented the highest callus initiation rate (40%) among all tested donor trees, whereas IN13 recorded the lowest rate with 4% (third experiment). ET maturation from each singular embryo of IN7, IN8, IN10 and IN21 was successfully achieved in SH medium containing 37,83 µM abscisic acid (ABA), 8% of polyethylene glycol (PEG-4000) and 4% maltose. The encapsulation technology was assessed on the obtained ET and its proliferation was observed after encapsulation
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