Investigation of hypersonic flow in the vki h3 wind tunnel: From facility characterization to boundary-layer interaction over low-temperature ablators

This work deals with the characterization, in terms of operating conditions, of the H3 hypersonic wind tunnel of the von Karman Institute for Fluid Dynamics (VKI), thus providing a detailed and structured benchmark for the evaluation of testing capabilities in hypersonic wind tunnels, and with the experimental study of the interaction between the boundary layer and the ablation process of low temperature ablative materials. The flow characteristics of the test section of the H3 WT have been assessed by using a pitot rake, for a wider range of operating conditions with respect to previous calibrations. A CFD analysis of the diffuser-ejector system has been carried out to assess its performance, and an experimental test campaign has been performed in order to validate the CFD analyses and completely characterize the facility operating conditions. Finally, a series of experiments with models of increasing size and different shapes has been carried out to determine the blockage effect in the tunnel test section. The H3 WT is then employed to study the boundary layer interaction with the ablative process on low temperature ablative models. These models have been built after having appropriately designed the sintering system. The Planar Laser Induced Fluorescence method has been applied to visualize the flow behavior: a laminar-turbulent transition due to the ablation process has been observed, together with the main flow structures

Predictors of Hepatocellular Carcinoma Early Recurrence in Patients Treated with Surgical Resection or Ablation Treatment: A Single-Center Experience

Introduction: Hepatocellular carcinoma (HCC) is the sixth most diagnosed malignancy and the fourth leading cause of cancer-related death worldwide, with poor overall survival despite available curative treatments. One of the most crucial factors influencing survival in HCC is recurrence. The current study aims to determine factors associated with early recurrence of HCC in patients with BCLC Stage 0 or Stage A treated with surgical resection or local ablation. Materials and Methods: We retrospectively enrolled 58 consecutive patients diagnosed with HCC within BCLC Stage 0 or Stage A and treated either by surgical resection or local ablation with maximum nodule diameter 20 mm (HR 4.5, 95% C.I. 3.9–5.1), platelet count 2 (HR 2.7, 95% C.I. 2.2–3.3). Discussion and Conclusions: Our results are in line with the current literature. Male gender and tumor nodule dimension are the main risk factors associated with early HCC recurrence. Platelet count and other combined scores can be used as predictive tools for early HCC recurrence, although more studies are needed to define cut-offs

Expansion of elevational range in a forest pest: Can parasitoids track their hosts?

We are thankful to Karim Senhadji and Ramon Ruiz-Puche for their help during the field work, and to Sara Garcia Morato for her contribution to quantifying rates of parasitism in PPM clutches at the laboratory. Two anonymous referees contributed to improve the manuscript. This study was supported by projects PROPINOL (PN22/2008), GESBOME (P06-RNM-1890) from Junta de Andalucia, REMEDINAL TE-CM (S2018/EMT-4338) from Comunidad de Madrid, ADAPTAMED (LIFE14 CCA/ES/000612) from LIFE program, and GILES (PCIN-2016-150) from the ERANET-LAC H2020 Programme.Gradients in elevation impose changes in environmental conditions, which in turn modulate species distribution and abundance as well as the interactions they maintain. Along the gradient, interacting species (e.g., predators, parasitoids) can respond to changes in different ways. This study aims to investigate how egg parasitism of a forest pest, the pine processionary moth (PPM), Thaumetopoea pityocampa, vary along an elevational gradient (190-2000 m.a.s.l.) in a mountain range of SE Spain, including areas of recent elevational expansion, for a seven years period (2008-2014). We used generalized linear mixed models to ascertain the effect of both elevation and the winter North Atlantic Oscillation (NAO) index (a proxy of interannual climatic conditions) on the rate of parasitism, and the occurrence probabilities of two parasitoid species: a PPM specialist and a generalist species. Since four pine species are stratified along the elevational gradient, we repeated all the analyses separately for lowlands (190-1300 m. a.s.l.) and uplands (1350-2000 m. a.s.l.). Results showed a decrease in both parasitism rate and probability of occurrence of the two main parasitoid species with elevation, although decline was more severe for the specialist species. The effect of elevation was more conspicuous and intense in uplands than in lowlands. Positive NAO winter values, associated with cold and dry winters, reduced the rate of parasitism and the probability of occurrence of the two main parasitoid species-but particularly for the generalist species-as elevation increases. In a context of climate warming, it is crucial to mitigate PPM elevational and latitudinal expansion. Increasing tree diversity at the PPM expansion areas may favor the establishment of parasitoids, which could contribute to synchronizing host- parasitoid interactions and minimize the risk of PPM outbreaks.Junta de Andalucia PN22/2008REMEDINAL TE-CM from Comunidad de Madrid S2018/EMT-4338ADAPTAMED from LIFE program LIFE14 CCA/ES/000612GILES from the ERANET-LAC H2020 Programme PCIN-2016-150Junta de Andalucia P06-RNM-189

InflateSail de-orbit flight demonstration results and follow-on drag-sail applications

The InflateSail (QB50-UK06) CubeSat, designed and built at the Surrey Space Centre (SSC) for the Von Karman Institute (VKI), Belgium, was one of the technology demonstrators for the European Commission’s QB50 programme. The 3.2 kg 3U CubeSat was equipped with a 1 metre long inflatable mast and a 10m2 deployable drag sail. InflateSail's primary mission was to demonstrate the effectiveness of using a drag sail in Low Earth Orbit (LEO) to dramatically increase the rate at which satellites lose altitude and re-enter the Earth's atmosphere and it was one of 31 satellites that were launched simultaneously on the PSLV (polar satellite launch vehicle) C-38 from Sriharikota, India on 23rd June 2017 into a 505km, 97.44o Sun-synchronous orbit. Shortly after safe deployment in orbit, InflateSail automatically activated its payload. Firstly, it inflated its metrelong metal-polymer laminate tubular mast, and then activated a stepper motor to extend four lightweight bi-stable rigid composite (BRC) booms from the end of the mast, so as to draw out the 3.1m x 3.1m square, 12m thick polyethylene naphthalate (PEN) drag-sail. As intended, the satellite immediately began to lose altitude, causing it to re-enter the atmosphere just 72 days later – thus successfully demonstrating for the first time the de-orbiting of a spacecraft using European inflatable and drag-sail technologies. The InflateSail project was funded by two European Commission Framework Program Seven (FP7) projects: DEPLOYTECH and QB50. DEPLOYTECH had eight European partners including DLR, Airbus France, RolaTube, Cambridge University, and was assisted by NASA Marshall Space Flight Center. DEPLOYTECH’s objectives were to advance the technological capabilities of three different space deployable technologies by qualifying their concepts for space use. QB50 was a programme, led by VKI, for launching a network of 50 CubeSats built mainly by university teams all over the world to perform first-class science in the largely unexplored lower thermosphere. The boom/drag-sail technology developed by SSC will next be used on a third FP7 Project: RemoveDebris, launched in 2018, which will demonstrate the capturing and de-orbiting of artificial space debris targets using a net and harpoon system. This paper describes the results of the InflateSail mission, including the observed effects of atmospheric density and solar activity on its trajectory and body dynamics. It also describes the application of the technology to RemoveDebris and its potential as a commercial de-orbiting add-on package for future space missions

Ground Testing Investigation of Hypersonic Transition Phenomena for a Re-Entry Vehicle

Aerodynamics, Wind Energy & PropulsionAerospace Engineerin

Measurement of internal stresses and of the temperature dependence of the matrix yield stress in metal matrix composites from thermal expansion curves

In a study of the thermal expansion behaviour of a variety of metal matrix composites, it appeared to the authors that a wealth of information could be extracted from thermal expansion curves. In the present work they aim at showing how a fairly straightforward analysis of these curves can provide quantitative data on the internal stresses and on the temperature dependence of the yield stress of the matrix. The method is illustrated on the basis of the thermal expansion curves of a composite consisting of an Al-3% Mg matrix reinforced by 30 vol.% continuous SiC fibres (Nicalon).Anglai

Production of enzymes from rice husks and wheat straw in solid state fermentation

In Europe, the agricultural wastes represent a significant potential for the development of biorefineries in different sectors such as cereals. The residues from the processing of grains are about 11 million tons/year of dry basis (Di Biasi et al., 1997). Recovery of phytochemicals as well as the energetic valorization of the plant matrixes needs the demolition of the wall cell plants. Over the past 30 years, it has become clear that research on the degradation of lignocellulose by fungi may lead to other industrial applications (Crawford and Crawford, 1980). Hydrolitic demolition by lignocellulosic enzymes is one of the most studied approach. In recent years, SSF has received more and more interest from researchers, since several studies for enzymes (Pandey et al., 1999), flavours (Ferron et al., 1996), colourants (Johns and Stuart, 1991) and other substances of interest to the food industry have shown that SSF can give higher yields (Tsuchiya et al., 1994) or better product characteristics than submerged fermentation (SmF) (Acu\uf1a-Arg\ufcelles et al, 1995). Using of agro-industrial residues as substrates in SSF processes provides an alternative avenue and value-addition to these otherwise under- or non-utilized residues. Solid-state fermentation (SSF) has been defined as the fermentation process which involves solid matrix and is carried out in absence or near absence of freewater; although, the substrate must possess enough moisture to support growth and metabolism of the microorganism. The solid matrix could be either the source of nutrients or simply a support impregnated by the proper nutrients that allows the development of the microorganisms. Fungi and yeast were termed as suitable microorganisms for SSF according to the theoretical concept of water activity, where as bacteria have been considered unsuitable (Chinn et al., 2007). On one hand, by utilizing the low cost agricultural residues, SSF adds on to economic feasibility of the process (Robinson and Nigam, 2003) and on other hand it solves the problem of its disposal which otherwise cause pollution (Singhania et al., 2009). Enzymes are among the most important industrial products obtained for human needs by microbial sources; in fact, a large number of industrial processes in the areas of industrial, environmental and food biotechnology utilize enzymes at some stage or the other. Solid state fermentation shows increasing interest for the production of enzymes, specially where the raw fermented waters may be used directly as enzyme sources (Pandey et al., 1999). White rot fungi such as Pleurotus ostreatus produce a wide range of extracellular enzymes to degrade complex lignocellulosic substrates into soluble substances that can be used as nutrients (Giardina et al., 1995; Marzullo et al., 1995). The objective of this study is to induce the production of lignocellulosic enzymes through the growth Pleurotus ostreatus in solid state fermentation using agro-food wastes as substrates: rice husks and wheat stra