211 research outputs found
Constrained sloshing of liquid mercury in a flexible spherical tank
The mercury propellant tank system developed for use with solar electric propulsion was studied to analytically determine the resonant frequencies of the tank system and compare them with the anticipated control natural frequency of the spacecraft. The system consisted of a stainless steel spherical shell and a hemispherical elastometric diaphragm. The major analytical tool used was the NASTRAN program. Six mathematical models were developed. Resonant frequencies for six harmonics were obtained for each of the six models considered. The results show that the lowest resonant frequency for the tank system is about an order of magnitude greater than the anticipated control frequency of the spacecraft
Comparison between carcasses of artificially suckled I.H.D.H. (Italian Heavy Draught Horse) foals slaughtered at 6 months and traditional carcasses obtained by foals slaughtered at 11 and 18 months
Aim of the study was the evaluation of a innovative I.H.D.H. carcass production sys- tem in order to improve the conditions for mare's milk production. In the trial were used 18 foals, subdi- vided in three randomized groups of 6 animals each. Every group was slaughtered at a different age: 6 months (artificially suckled), 11 months and 18 months (naturally suckled, following traditional rearing systems). Six months old foals carcasses were characterized by 75.59 % of lean, 12.79 % of fat and 11.64 % of bone. Six months foals carcasses showed the lean end the fact respectively higher (P<0.001) end lower (P<0.001) than 18 months ones (P<0.001), and the bone higher than 11 months foals (P<0.001). Six months hind quarter incidence was 65.00 %, more than found for 18 months carcasses (P<0.001). Moreo- ver, 6 months carcasses showed an first quality cuts incidence higher than 11 months foals (P<0.01)
Statistical Model Checking of Human-Robot Interaction Scenarios
Robots are soon going to be deployed in non-industrial environments. Before
society can take such a step, it is necessary to endow complex robotic systems
with mechanisms that make them reliable enough to operate in situations where
the human factor is predominant. This calls for the development of robotic
frameworks that can soundly guarantee that a collection of properties are
verified at all times during operation. While developing a mission plan, robots
should take into account factors such as human physiology. In this paper, we
present an example of how a robotic application that involves human interaction
can be modeled through hybrid automata, and analyzed by using statistical
model-checking. We exploit statistical techniques to determine the probability
with which some properties are verified, thus easing the state-space explosion
problem. The analysis is performed using the Uppaal tool. In addition, we used
Uppaal to run simulations that allowed us to show non-trivial time dynamics
that describe the behavior of the real system, including human-related
variables. Overall, this process allows developers to gain useful insights into
their application and to make decisions about how to improve it to balance
efficiency and user satisfaction.Comment: In Proceedings AREA 2020, arXiv:2007.1126
Effects of legume seeds and processing treatment on growth, carcass traits and blood constituents of fattening lambs
This study aimed to evaluate the effects of faba bean, white lupin and pea seed when fed as protein supplements on growth performance, carcass characteristics and haematological characteristics of growing lambs. Forty-eight Gentile di Puglia male lambs, weaned at 38 ± 2 days old with an average initial bodyweight of 12.8 ± 0.5 kg, were divided into six homogenous groups. The six dietary treatments were RFB (diet containing raw faba bean seeds); EFB (diet containing extruded faba bean seeds); RL (diet containing raw lupin seeds); EL (diet containing extruded lupin seeds); RP (diet containing raw pea seeds); and EP (diet containing extruded pea seeds). Feeding lupin seeds reduced average daily feed intake compared with the other protein sources. Carcass conformation, loin weight as a percentage of half-carcass weight, and fat weight as a percentage of loin weight improved in the lambs that consumed both EP and RP diets. Extrusion reduced hide weight as a percentage of empty bodyweight and fat weight as a percentage of leg weight. The protein source had a significant effect on glucose and total cholesterol concentrations, albumin, α1-globulin, β-globulin, and γ-globulin percentages and albumin-globulin ratios. The processing treatment decreased total cholesterol concentrations. Thus, feeding the various legumes did not affect growth performance, but only carcass characteristics; changes which may be due to the differences in feed intake. Extrusion also had minor effects, and further work is required to investigate the use of these protein sources, both raw and extruded.Keywords: extrusion, faba bean, haematology, lupin, pea, protein source, slaughter dat
Effects of compost organic amendments on chemical composition and in vitro digestibility of alfalfa (Medicago sativa L.)
The following fertiliser treatments were compared during the years 2002 and 2003 on alfalfa forage (Medicago sativa L.): compost obtained from the organic fraction of the Municipal Solid Waste (MSW); olive pomace compost (OPC); mineral fertiliser (Min). All the treatments allowed a distribution of 75kg ha-1 of P2O5. Three cuttings occurred: at 168, 206 and 351 days after compost application (DAA) in 2002; 119, 152 and 320 DAA in 2003. Cumulative biomass and dry matter yields were measured during each experimental year. Furthermore, chemical composition and in vitro digestibility of dry matter (DMd), organic matter (OMd), crude protein (CPd) and NDF (NDFd) were determined. MSW treatment showed a significantly (P<0.01) higher content of ADL than OPC and Min (77.0, 66.0 and 65.0g kg-1 DM, respectively). Fertiliser treatments also affected (P<0.01) digestibility parameters. In fact, DMd and OMd values showed the same trend with lower percentages in MSW treatment than in the OPC and Min ones. The NDFd differed in all treatments having the highest value in OPC (40.1%). The results indicated that the soil distribution of organic materials offer the possibility to reduce the application of mineral fertilisers and production costs without decreasing alfalfa yield, forage chemical composition and in vitro digestibility
Characterization of the cellular damage induced by Aflatoxin B1 in sea bream (Sparus aurata Linnaeus, 1758) hepatocytes
Gilthead sea bream (Sparus aurata L.) is one of the most intensively farmed fish spe- cies in the Mediterranean, greatly studied for the relevant economic value, although its sensitivity to Aflatoxin B1 (AFB1) has to be investigated, yet. The aim of this study was to perform an in vitro evalua- tion of cytotoxic potential of AFB1 on S. aurata hepatocytes in order to grade the range of AFB1 toxicity, and the boundary between acute and long-term toxicity. Primary monolayer cultures of hepatocytes from S. aurata juveniles were treated with a wide range of concentrations from 5x103 ng/ml to 2x10 2x10-5 ng/ml of AFB1 for a different period of exposure (24, 48, 72 hours). The cytotoxic activity was characterized by MTT reduction assay. After each exposition hepatocytes were examined for morphologic alterations and apoptosis induction. AFB1 exposure significantly reduced cell viability in a dose- and time-depend- ent manner. Dose-response curves obtained after 24, 48 and 72 hrs revealed that prolonged exposure times lead to a significant increase of the toxicpotencyofAFB toxic potency of AFB AFB1. Ourresultsdemonstratethat Our results demonstrate that S. aurata hepatocytes are highly sensitive to AFB1 exposure. Such scientific findings could provide new insights to investigate the real impact of aflatoxin on marine farmed fish
Effect of an extruded linseed diet on meat quality traits in Nero Lucano pigs
The study aimed to evaluate the effect of a diet containing extruded linseed (Linum usitatissimum L.) on growth performances, carcass traits and meat quality in Nero Lucano pigs. Sixteen male piglets were weaned at about 50 days of age and divided into two homogeneous groups fed a control diet (C) or a diet containing 3% extruded linseed (EL). The trial lasted 32 weeks and pigs were slaughtered at 9 months of age. Samples from the Longissimus dorsi (Ld) muscle were analysed to assess physical and chemical parameters and intramuscular fatty acid composition. Average daily gain, feed intake and feed conversion ratio were not affected by the diet. Pigs fed the C diet showed a significantly greater slaughter weight in comparison to the EL group (116.50 vs 108.25 kg) Meat pH and chemical composition were not influenced by the diet. No differences were found for shear force (WBS) in raw meat, while cooked meat of the EL group showed a lower WBS value. The EL diet significantly lowered total SFA and increased total PUFA, of both n-6 and n-3 series. Among the n-6, significant differences between dietary treatments were found for linoleic acid. As for the n-3 series, EL feeding significantly enhanced linolenic acid, EPA, DPA and DHA. Feeding EL also significantly lowered the PUFA/SFA and n-6/n-3 ratios and the AI and TI, with benefits for human health. In conclusion, dietary supplementation with 3% EL didn't affect growth performance while it improved the fatty acid profile of meat.
Keywords: fatty acid profile, feeding, flaxseed, por
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