Cubesat mission with technological demonstrator payload for high data rate downlink and health monitoring

The HyperCube payload will be composed by two different technological experiment, an high data-rate C band antenna, and a demonstrator for a remote structural health monitoring system. The first one has been thought with the aim to give Cubesats the capability to download an high quantity of data; it could be useful either if the data requiring the high data-rate downlink is on-board generated or simply retransmitted. The applications for which this payload could be used are several; an example for the first category of application is to download the data generated by another payload; the high data-rate capability could be necessary due to the narrow visibility window with the ground station, affected also by the absence of an active AOCS subsystem, which makes difficult the alignment of the on board antenna with the ground one. But the C band antenna could also be used to act as a “space–repeater”, downloading up–linked information. The second payload is related to the need to take under strictly control the health of the structures (not only the ones strictly belonging to primary structures, but also that of any subsystem component). In order to do that, smart materials are integrated into the structural component that need to be monitored; in particular, piezoelectric patches are used as sensors. As the structure is stressed, and the integrated piezoelectric sensors are subjected to mechanical deformation, they produce an electric signal; acquiring and properly studying the produced signal it is possible to monitor the mechanical condition of the structures. The health monitoring system is completed by a MicroController Unit which acquires, samples and stores the signal produced, and a transmitting system, which could be the C band antenna, or the TT&C antenna which each satellite needs

Study on an air-launched constellation of tactical micro-satellites for defence Use

The great attention on air-launched microsatellites is due on one hand to the possibilities given by the miniaturization push, making the same performances of traditional satellites achievable with smaller systems, and on the other hand to the disruptive advantages allowed by air-launch techniques, providing Italy not only with an autonomous launch capability, but also with the flexibility to choose the orbit inclination and the launch time, enabling a responsive approach at lower costs respect to ground based launches. In this study, several issues related to this subject are analyzed. A constellation of four microsatellites for electro-optical Earth Observation (EO) is conceived, namely ITAFμSAT (i.e. ITalian Tactical Formation of μ-SATellites). ITAFμSAT is designed to achieve a sub-metric spatial resolution and to offer a high revisit frequency on a specified target area to satisfy military needs. ITAFμSAT is designed to be responsive and the system is conceived to guarantee a fast access to space since the mission is called, through a Plug-and-Play (PnP) approach; to provide Italy with a proprietary system, built, launched and operated on-purpose for its contingent needs; and to complete the information supplied by other EO systems with high quality images captured in a very short time

Substance Use in a Rural High School: Perception and Reality

Adolescent substance use in U.S. rural communities is now equal to or greater than urban use for many substances (Shears, Edwards, & Stanley, 2006). Despite this fact, a great deal of research and preventative strategies focuses on urban and suburban populations. To provide a better understanding of alcohol and drug use among adolescents in rural contexts, we conducted an analysis of 636 Georgia students at a rural high school. We also analyzed data regarding 61 teachers and administrators at this high school. Our data analysis reveals four primary findings. First, consistent with previous research in other contexts (Aas and Klepp 1992; Perkins, Haines, and Rice 2005), we find that rural high school students overestimate their classmates’ usage. Second, we find considerable variation in use between freshmen, sophomores, juniors, and seniors. Third, we find differences between male and female students regarding their actual drug use as well as their perceptions of friends and classmates’ use. Fourth, we find that teachers and administrators overestimate students’ use. Based on these findings, we suggest that the best approach to deter substance use and abuse is not a “blanket” approach for all four grades, but rather a grade-specific approach that takes gender into consideration

Experimental investigation of unsteady flows at large incidence angles in a linear oscillating cascade

The aerodynamics of a cascade of airfoils oscillating in torsion about the midchord is investigated experimentally at a large mean incidence angle and, for reference, at a low mean incidence angle. The airfoil section is representative of a modern, low aspect ratio, fan blade tip section. Time-dependent airfoil surface pressure measurements were made for reduced frequencies up to 0.8 for out-of-phase oscillations at Mach numbers up to 0.8 and chordal incidence angles of 0 deg and 10 deg. For the 10 deg chordal incidence angle, a separation bubble formed at the leading edge of the suction surface. The separated flow field was found to have a dramatic effect on the chordwise distribution of the unsteady pressure. In this region, substantial deviations from the attached flow data were found with the deviations becoming less apparent in the aft region of the airfoil for all reduced frequencies. In particular, near the leading edge the separated flow had a strong destabilizing influence while the attached flow had a strong stabilizing influence

Oscillating cascade aerodynamics at large mean incidence

The aerodynamics of a cascade of airfoils oscillating in torsion about the midchord is investigated experimentally at a large mean incidence angle and, for reference, at a low mean incidence angle. The airfoil section is representative of a modern, low aspect ratio, fan blade tip section. Time-dependent airfoil surface pressure measurements were made for reduced frequencies of up to 1.2 for out-of-phase oscillations at a Mach number of 0.5 and chordal incidence angles of 0 deg and 10 deg; the Reynolds number was 0.9 x l0(exp 6). For the 10 deg chordal incidence angle, a separation bubble formed at the leading edge of the suction surface. The separated flow field was found to have a dramatic effect on the chordwise distribution of the unsteady pressure. In this region, substantial deviations from the attached flow data were found with the deviations becoming less apparent in the aft region of the airfoil for all reduced frequencies. In particular, near the leading edge the separated flow had a strong destabilizing influence while the attached flow had a strong stabilizing influence

Optimized conversion of wheat straw into single cell oils by Yarrowia lipolytica and Lipomyces tetrasporus and synthesis of advanced biofuels

This paper deals with the optimized conversion of undetoxified wheat straw hydrolysates into microbial lipids by two oleaginous yeasts, Yarrowia lipolytica and Lipomyces tetrasporus. Wheat straw were pretreated by steam explosion at 203 degrees C for 300 s and hydrolysed at 20% solid-to-liquid ratio by using an enzymatic loading of 15 FPU/ g substrate. The mixed wheat straw hydrolysates (WHS) contained 86 gL-1 glucose and 22 gL-1 xylose, 2.3 gL-1 acetic acid, 0.9 gL-1 furanic compounds. The fermentation process was optimized in terms of the inoculum age and density, medium composition, and bioreactor feeding strategy. In particular, the different capacity of the two yeasts to overcome the toxic effect of the biomass degradation by-products, in different inoculum ages, was deeply investigated. Two hydrolysates concentration were tested: WSH containing 86 gL-1 glucose and 22 gL-1 xylose and the diluted medium containing 40 gL-1 glucose and 22 gL-1 xylose. The results indicated that both yeasts were able to detoxify WSH and grow on undetoxified hydrolysates as effect of the intrinsic capacity to metabolize the furan derivatives. Y. lipolytica was able to detoxify the medium in all the investigated set-ups, while L. tetrasporus was able to detoxify the medium only if inoculated in the stationary phase of growth. After the process optimization in shaken flasks, the production of Single Cell Oils (SCOs) by L. tetrasporus was carried out in a medium-scale bioreactor of 10L obtaining lipid yield and cell content of 21% and 62%, respectively. The extracted SCOs, with high oleic and palmitic acid content, were converted into biodiesel displaying overall features in accordance with international biodiesel standards, namely ASTM and EN 14214

Genome Sequencing and Comparative Analysis of Three Hanseniaspora uvarum Indigenous Wine Strains Reveal Remarkable Biotechnological Potential

A current trend in winemaking has highlighted the beneficial contribution of non-Saccharomyces yeasts to wine quality. Hanseniaspora uvarum is one of the more represented non-Saccharomyces species onto grape berries and plays a critical role in influencing the wine sensory profile, in terms of complexity and organoleptic richness. In this work, we analyzed a group of H. uvarum indigenous wine strains as for genetic as for technological traits, such as resistance to SO2 and beta-glucosidase activity. Three strains were selected for genome sequencing, assembly and comparative genomic analyses at species and genus level. Hanseniaspora genomes appeared compact and contained a moderate number of genes, while rarefaction analyses suggested an open accessory genome, reflecting a rather incomplete representation of the Hanseniaspora gene pool in the currently available genomes. The analyses of patterns of functional annotation in the three indigenous H. uvarum strains showed distinct enrichment for several PFAM protein domains. In particular, for certain traits, such as flocculation related protein domains, the genetic prediction correlated well with relative flocculation phenotypes at lab-scale. This feature, together with the enrichment for oligo-peptide transport and lipid and amino acid metabolism domains, reveals a promising potential of these indigenous strains to be applied in fermentation processes and modulation of wine flavor and aroma. This study also contributes to increasing the catalog of publicly available genomes from H. uvarum strains isolated from natural grape samples and provides a good roadmap for unraveling the biodiversity and the biotechnological potential of these non-Saccharomyces yeasts

Pilot Scale Evaluation of Wild Saccharomyces cerevisiae Strains in Aglianico

In winemaking, the influence of Saccharomyces cerevisiae strains on the aromatic components of wine is well recognized on a laboratory scale, but few studies deal with the comparison of numerous strains on a pilot scale fermentation. In this scenario, the present work aimed to validate the fermentative behavior of seven wild S. cerevisiae strains on pilot-scale fermentations to evaluate their impact on the aromatic profiles of the resulting wines. The strains, isolated from grapes of different Italian regional varieties, were tested in pilot-scale fermentation trials performed in the cellar in 1 hL of Aglianico grape must. Then, wines were analyzed for their microbiological cell loads, main chemical parameters of enological interest (ethanol, total sugars, fructose, glucose, total and volatile acidity, malic and lactic acids) and volatile aroma profiles by GC/MS/SPME. Seventy-six volatile compounds belonging to six different classes (esters, alcohols, terpenes, aldehydes, acids, and ketones) were identified. The seven strains showed different trends and significant differences, and for each class of compounds, high-producing and low-producing strains were found. Since the present work was performed at a pilot-scale level, mimicking as much as possible real working conditions, the results obtained can be considered as a validation of the screened S. cerevisiae strains and a strategy to discriminate in real closed conditions strains able to impart desired wine sensory features