Results of the qualification test campaign of a Pulsed Plasma Thruster for Cubesat Propulsion (PPTCUP)

Pulsed Plasma Thruster for Cubesat Propulsion (PPTCUP) is an ablative pulsed plasma thruster designed with the aim of providing translational and orbital control to Cubesat platforms. The qualification model presented in this paper has been developed by Mars Space Ltd, Clyde Space Ltd and the University of Southampton to produce a versatile “stand-alone” module that can be bolted on the Cubesat structure, allowing the orbital control along the X or Y-axis of the satellite. An extensive and complete test campaign to qualify the unit for space flight, which includes electromagnetic compatibility (EMC) characterization, thermal cycling and mechanical tests, has been performed according to the NASA GEVS procedures. PPTCUP is characterized by an averaged specific impulse of 655±58 s and a deliverable total impulse of 48.2±4.2 Ns. Finally, it has been found that the unit is compliant with the EMC requirements and can successfully withstand the thermal and mechanical loads typical of a Cubesat space mission

Development of an engineering optimization tool for miniature pulsed plasma thrusters

Pulsed Plasma Thrusters (PPT) are an established technology for compact thrust propulsion systems. Although PPT optimization has been performed previously it requires complex numerical codes. Although the scaling laws have been suggested they mainly applicable for large thrusters when edge effects can be neglected. A new 0D pulsed inductive acceleration model has been developed which links together the dynamics of the current sheet with the plasma dimensions and ionization processes. The model novelty is in a self-consistent estimation of the plasma sheet properties (temperature, density, thickness) driven by the magnetic pinch pressure and propellant ablation together with its simplicity. Parametric studies have been performed in an attempt to arrive at modified scaling laws for small PPTs

Prevalence of pain in the departments of surgery and oncohematology of a paediatric hospital that has joined the project "Towards pain free hospital"

Background. Among hospitalized adults and children pain is undertreated. This study wants to assess the effectiveness of pain therapy in two departments of a large children's hospital. Materials and Methods. During a single day work three committees, administering a questionnaire to patients or parents, have evaluated the adherence to international recommendations (JCI and WHO) in the management of analgesic therapy. Patient demographics, prevalence and intensity (moderate and/or severe) of pain (during hospitalization, 24 hours before and at the time of the interview), analgesia (type, route, duration and frequency of administration) and Pain Management Index (=analgesic score-pain score) were recorded. Results. 75 patients participated in the study (age: 2 months up to 24 years, mean 7.8 ± 6). During hospitalization 43 children (57%) had no pain while 32 (43%) have experienced pain. 22 children (29 %) had pain 24 hours before and 12 (16%) at the time of the interview. The average value of the PMI was -0.8±1.3 with a minimum of -3 and a maximum of +2: 60% (19) of the children had a PMI less than 0 (undertreated pain) while 40% (13) had a value=or > 0. Out of 32 patients who needed an analgesic therapy 14 (44%) received an around-the-clock dosing, 8 (25%) an intermittent therapy and 10 (31%) no treatment.17 (77 %) were the single drug therapy and 5 (23%) the multimodal ones. Conclusion. The prevalence of pain in the two departments is high. The main cause is that knowledge is not still well translated into clinical practice

Italian network for obesity and cardiovascular disease surveillance: A pilot project

<p>Abstract</p> <p>Background</p> <p>Also in Mediterranean countries, which are considered a low risk population for cardiovascular disease (CVD), the increase in body mass index (BMI) has become a public health priority. To evaluate the feasibility of a CVD and obesity surveillance network, forty General Practitioners (GPs) were engaged to perform a screening to assess obesity, cardiovascular risk, lifestyle habits and medication use.</p> <p>Methods</p> <p>A total of 1,046 women and 1,044 men aged 35–74 years were randomly selected from GPs' lists stratifying by age decade and gender. Anthropometric and blood pressure measurements were performed by GPs using standardized methodologies. BMI was computed and categorized in normal weight (BMI 18.5–24.9 kg/m²), overweight (BMI 25.0–29.9 kg/m²) and obese (BMI ≥ 30 kg/m²). Food frequency (per day: fruits and vegetables; per week: meat, cheese, fish, pulses, chocolate, fried food, sweet, wholemeal food, rotisserie food and sugar drink) and physical activity (at work and during leisure time) were investigated through a questionnaire. CVD risk was assessed using the Italian CUORE Project risk function.</p> <p>Results</p> <p>The percentage of missing values was very low. Prevalence of overweight was 34% in women and 50% in men; prevalence of obesity was 23% in both men and women. Level of physical activity was mostly low or very low. BMI was inversely associated with consumption of pulses, rotisserie food, chocolate, sweets and physical activity during leisure time and directly associated with consumption of meat. Mean value of total cardiovascular risk was 4% in women and 11% in men. One percent of women and 16% of men were at high cardiovascular risk (≥ 20% in 10 years). Normal weight persons were four times more likely to be at low risk than obese persons.</p> <p>Conclusion</p> <p>This study demonstrated the feasibility of a surveillance network of GPs in Italy focusing on obesity and other CVD risk factors. It also provided information on lifestyle habits, such as diet and physical activity.</p

The effects of intra- and interspecific competitions on personality and individual plasticity in two sympatric brown frogs

We studied how individuals modify their behavior in response to inter- and intraspecific competitors and how these changes affected the pattern of variation between populations and species. As study models, we used tadpoles of two brown frogs, Rana latastei and R. dalmatina. Since R. latastei is always sympatric to R. dalmatina, whereas R. dalmatina is sympatric to R. latastei only in the periphery of its range, we predicted a stronger response to heterospecifics in R. latastei than in R. dalmatina and, within each species, in syntopic than in allotopic populations. To test these predictions, we raised tadpoles, from either syntopic or allotopic populations, in either syntopy or allotopy and repeatedly tested them in open field trials in the presence of a caged conspecific, a caged heterospecific, or an empty cage. As predicted, we found that, on average, R. latastei tadpoles modified their behavior across treatments more than R. dalmatina tadpoles and individuals from the syntopic population changed more than their conspecifics from the allotopic population. In both species, the pattern of variation at the individual level mirrored that at the population and species levels providing no evidence for an individual-by-environment interaction (I x E). Besides these differences, however, individuals of the two species also showed unpredicted and context-independent behavioral differences, suggesting that there might be more to interspecific behavioral variation than the effect of selection by heterospecific competitors.Significance statementDoes the distribution range of a species influence the evolution of plastic behaviors to heterospecific competitors? And how do differences in plasticity affect animal personality? To answer these questions, we raised tadpoles of two brown frog species, Rana dalmatina and R. latastei, and studied how the amount and the type of their swimming varied with the presence of the other species. R. latastei, whose small distribution range fully overlaps with that of R. dalmatina, plastically responds to it, whereas R. dalmatina, which is sympatric to R. latastei only in the periphery of its broader range, does not. These interspecific differences mirrored those among individuals: tadpoles of both species show repeatable behaviors, but only those of R. latastei plastically changed their behavior with the presence of the other species; however, neither R. latastei nor R. dalmatina show among-individual variation in plasticity

Purity control of some Chinese crude herbal drugs marketed in Italy

In the present study, 10 Chinese crude herbal drugs marketed in Italy (Radix Ginseng, Radix Astragali, Rhizoma Coptidis, Rhizoma Atractylodis Macrocephalae, Radix Bupleuri, Radix Rehmanniae, Radix Paeoniae Alba, Pericarpium Citri Reticulatae, Radix Polygalae, Radix Salviae Miltiorrhizae) were analysed by the following purity assays: foreign matter, total ash, microbial and heavy metal contamination. The presence of parasites was shown in two samples; moreover, level of ash (in three samples), lead content (in one sample) and total viable aerobic count (in one sample), were higher than the limits set by the European or Italian Pharmacopoeias. Our results show some purity issues and underline the importance of the quality control