2,901 research outputs found
Copper and Barium Abundances in the Ursa Major Moving Group
We present Cu and Ba abundances for 7 G-K dwarf stars, members of the
solar-metallicity, 0.3 Gyr old Ursa Major Moving Group. All analyzed member
stars show [Ba/Fe] excesses of +0.3-plus, associated with [Cu/Fe] deficiencies
of up to -0.23 dex. The present results suggest that there is an
anti-correlation between the abundances of Cu and the heavy elements produced
by the main component of the neutron capture s-process. Other possible
anomalies are Na and C deficiencies with respect to normal solar-metallicity
stars. The new data do not confirm the recent claim that the group member
HR6094 is a Ba dwarf star.Comment: 8 pages, 6 figures, accepted to MNRA
Net electricity and heat generated by reusing Mediterranean agro-industrial by-products
The necessity to investigate suitable alternatives to conventional fossil fuels has increased interest in several renewable energy resources, especially in biomasses that are widely available and make it possible to reach environmental and socio-economic improvements. Among solutions for bioenergy production, anaerobic digestion technology allows biogas production by reusing agricultural residues and agro-industrial by-products. By considering the basic concepts of the Biogasdoneright® method, the objective of this study was to estimate the theoretical potential net electricity and heat production from anaerobic digestion of citrus pulp and olive pomace highly available worldwide. A model was developed and applied in a study area of the Mediterranean basin, where the biogas sector is still very limited despite the importance of both agricultural and agro-industrial activities, especially with regard to citrus and olive cultivation processing. Firstly, the application of a geographical information system (GIS) software tool allowed the estimation of the biogas potentially produced from citrus pulp and olive pomace re-use. Then, the development of a technical assessment demonstrated that 15.9 GWh electricity and 88,000 GJ heat per year could be generated from these by-products, satisfying approximate 17% of the electricity demand of the agricultural sector of the study area (90.2 GWh y −1 ). The achieved results could be relevant with regard to the intervention priorities established by the European Union related to the planning activities supported by the European Structural and Investment Funds within the Smart Specialisation Strategy
Seleção de fungos produtores de β-D-frutosiltransferase por fermentação em estado sólido
A enzima β-D-frutosiltransferase é responsável pela síntese de FOS (frutooligossacarídeos) a partir de sacarose por reação de transfrutosilação é produzida por diferentes micro-organismos, principalmente por fungos filamentosos. O objetivo deste trabalho foi selecionar a melhor linhagem fúngica produtora da -D-frutosiltransferase por fermentação em estado sólido, bem como o método de extração. A fermentação em estado sólido utilizando o substrato farelo de trigo umedecido com solução de sacarose atingindo 70% de umidade na concentração de esporos de 107 no tempo de 96 horas de crescimento. Todas as linhagens manipuladas apresentaram atividade hidrolítica, no entanto apenas uma linhagem não demonstrou atividade transfrutosilação. O isolado SIS 14 que pertence ao gênero Aspergillus sp. destacou-se pelos maiores valores em atividade no método de extração utilizando água destilada, apresentando 300,90 U/mL na atividade de transfrutosilação e na atividade hidrolítica de 155,74 U/mL. Contudo, pode-se perceber que dos solventes estudados a água destilada foi melhor obtendo o valor em atividade de transfrutosilação, como também a linhagem SIS 14 é promissora para a produção da β-D-frutosiltransferase
Effect of pH and temperature on phytase and biomass production by submerged fermentation with Aspergillus niger var. phoenicis URM 4924
Phytase production and biomass was evaluated in present work by submerged fermentation with Aspergillus niger var. phoenicis URM 4924. Experimental assays were done under different conditions of pH (4.0 to 8.0) and temperature (25 to 35 ºC), and the influence of these variables on the responses was studied through a 22 central composite design and response surface methodology. Phytase and biomass production were affected by the pH and temperature used during submerged fermentation. Phytase activity was increased in up to 7.8-fold (from 1.04 to 8.09 U/mL) and the ergosterol content was increased in up to 38-fold (from 9.3 to 354.09 μg/mL). The maximum values of both responses were achieved when using pH 4.0 and 30 ºC
Phytase production by Aspergillus niger var. phoenicis URM 4924 using cane molasses and rice brain
XI Reunião Regional Nordeste da SBBq | 4th International Symposium in Biochemistry of Macromolecules and BiotechnologyPhytase is a generic term used to describe an enzyme that hydrolyzes
phosphomonoester bonds from phytic acid, thereby liberating inorganic phosphorous,
consequently increasing the availability of phosphorous for the absorption. It is
presumed to be plant storage form of phosphate which also happens to have
considerable antinutritive effects for most animals. Phytate, a salt of phytic acid, is the
major storage form of phosphorus in typical animal feedstuffs. The aim of this study was
evaluate parameters of the medium, such as the concentrations of cane molasses and
rice brain in the production of phytase by Aspergillus niger var. phoenicis URM 4924,
using a factorial design. The experiments was carried out according to a 22 factorial
design with four center points, which were studied at three levels, cane molasses
concentration (1.0%, 1.5% and 2.0%) and the rice bran concentration (0.25%, 0.5% and
0.75%). Fermentations were carried out using 250 mL Erlenmeyer flasks, 30° C, 90 rpm,
pH 4.0, with addiction of saline solution (gL-1: KCl 0.5; MgSO4.7H2O 1.5; CaCl2.2H2O
2,0) for 72 hours of production. Phytase activity was determined by quantification of the
phosphate released from phytate during the enzymatic reaction using the method of
ammonium molybdate. The best conditions for phytase production (12.69 U/mL)
occurred using 0.75% of rice brain with 2.0% of cane molasses. These results
demonstrate the potential of cane molasses and rice brain in submerged fermentation
for the phytase production by A.CAPES and CNPqinfo:eu-repo/semantics/publishedVersio
Enhancing heat treatment efficacy for insect pest control: A case study of a CFD application to improve the design and structure of a flour mill
Heat treatment of the indoor environment of flour mills is an alternative technique to chemical fumigation for controlling insect pests. The aim of this research was to assess temperature distribution inside a flour mill during a heat treatment for insect pest control by computational fluid dynamics (CFD) modelling and simulation. The model was validated by using the average values of experimental data acquired during a heat treatment carried out in a flour mill, which is representative of the building materials and techniques used in the milling industry of South Italy. Simulations were carried out in steady-state conditions, and simulated data were validated by the average values of air and wall temperature measurements. Since the modelled temperature distribution in the mill fit the real one with a good accuracy (maximum error equal to 2.57 °C), the CFD model was considered reliable to simulate other operating conditions. Since it was observed that the internal surface temperatures of the mill were much lower than the value required for the success of the heat treatment, equal to 45 °C, the CFD model could be used for improving the effectiveness of heat treatments in the flour mill. Application of the proposed CFD model in the simulation of specific interventions could be aimed at improving both building performance and fan heaters' localisatio,n in order to find the best configuration
Sustainable Promotion of Traditional Rural Buildings as Built Heritage Attractions: A Heritage Interpretation Methodology Applied in South Italy
The study describes the methodology implemented to include a rural cultural heritage attraction within an existing tourist route, i.e., the Sicilian Roads of Wine (“Strade del vino”). The aim was to promote a traditional rural building (TRB) as a tourist attraction and diversify rural tourism offerings. By promoting TRB and wine and food, the rural tourism sector offers a significant opportunity to achieve sustainable socio-economic development in rural areas, rural diversification, and landscape preservation. The inclusion of the TRB within the visitor route is based on a detailed heritage analysis approach as an operative process which could enable the comprehension and collective use of the cultural sites. The valorization of a traditional rural building with wine cellars and oil mills, located within the Chiaramonte Gulfi (RG) boundary, will be described. The objective is to make an architectural heritage building made with local materials and following the traditional Sicilian building techniques accessible to tourists. Special attention is paid to restore the building by respecting its identity and relevant building regulations and focusing on a complete, sustainable approach regarding social, environmental, and economic factors
Kernel density estimation analyses based on a low power-global positioning system for monitoring environmental issues of grazing cattle
The use of wearable sensors that record animal activity in intensive livestock systems has become more and more frequent for both early detection of diseases and improving production quality. Their application may also be significant in extensive livestock systems, with infrequent farmer-to-animal contact. The pre-sent study aimed to prove the feasibility of a novel automatic sys- tem for locating and tracking cows in extensive livestock systems based on space-time data provided by a low-power global positioning system (LP-GPS). The information was used to study the pasture exploitation by the herd for modelling the environmental impacts of extensive livestock systems through geographical information systems (GIS). A customised device, placed within a rectangular PVC case compatible with the collar usually worn by animals, was equipped with an LP-GPS omnidirectional system, an integrated SigFox communication system, and a power supply. The experimental trial was conducted in an existing semi-natural pasture characterised by good pasture allowance and cultivated grazing areas. Ten cows were embedded with LP-GPS collars, and the data, i.e., geographical coordinates and the time intervals related to each cow detection, were recorded every 20 minutes. Data were collected through a specifically developed AppWeb to be further imported and elaborated by using a GIS software tool. In the GIS environment, the daily distances travelled by each cow were linked with heatmaps obtained by applying Kernel density estimation models from the points obtained from the LP-GPS col-lars. The study results made it possible to obtain information on some relevant aspects of livestock’s environmental issues. In detail, it was possible to acquire information on herd behaviour related to the use of the pasture, e.g., the area of the pasture most frequently used during the day, individual use of the pasture, and possible animal interactions. These results represent the first step towards further insights and research activities because monitoring of animal locations could reduce several environmental issues such as soil degradation and greenhouse emissions. r
Development of a CFD model to simulate natural ventilation in a semi-open free-stall barn for dairy cows
Natural ventilation is the most common passive cooling system in livestock buildings. The aim of this research is to assess airflow distribution inside a free-stall barn for dairy cows by computational fluid dynamics (CFD) modelling and simulation. The model is validated by using the average values of experimental data acquired in a free-stall barn, which is considered relevant because it is located in a region characterised by hot climate conditions during the summer that could induce animal heat stress. Simulations are carried out in steady-state conditions, and simulated data are validated by the average values of air velocity measurements. Since the modelled air velocity distribution in the barn fits the real one well, the CFD model is considered reliable to simulate other conditions. The application of the proposed CFD model in the simulation of specific building design alternatives could be aimed at studying the related airflow distribution in order to find the best configuration
Improving natural ventilation in renovated free-stall barns for dairy cows: Optimized building solutions by using a validated computational fluid dynamics model
Natural ventilation is the most used system to create suitable conditions, removing gases, introducing oxygen in livestock buildings. Its efficiency depends on several factors and above all on the number, the dimensions and the position of wall openings and internal layout of livestock buildings. The aim of this research was to develop optimized layout solutions for improving natural ventilation effectiveness in free-stall barns for dairy cows by using a CFD approach. A validated computational fluid dynamics (CFD) model was applied in a case study which is highly representative of building interventions for renovating the layout of free-stall barns for dairy cows located in an area of the Mediterranean basin. Firstly, dairy cow behaviour was analysed by visual examination of time-lapse video-recordings. Then, simulations were carried out by using the validated CFD model and changing the position of internal and external building elements (i.e., internal office and external buildings for milking) in order to find the best condition for the thermal comfort of the animals. The results showed that the best conditions were recorded for a new configuration of the building in terms of air velocity distribution within the resting area, the service alley and the feeding alley for dairy cows, and in the pens for calves. In this new layout, the office areas and the north-west wall openings were located by mirroring them along the transversal axis of the barn. Therefore, the CFD approach proposed in this study could be used during the design phase, as a decision support system aimed at improving the natural ventilation within the barn
- …