The slingshot effect: a possible new laser-driven high energy acceleration mechanism for electrons

We show that under appropriate conditions the impact of a very short and intense laser pulse onto a plasma causes the expulsion of surface electrons with high energy in the direction opposite to the one of propagation of the pulse. This is due to the combined effects of the ponderomotive force and the huge longitudinal field arising from charge separation ("slingshot effect"). The effect should also be present with other states of matter, provided the pulse is sufficiently intense to locally cause complete ionization. An experimental test seems to be feasible and, if confirmed, would provide a new extraction and acceleration mechanism for electrons, alternative to traditional radio-frequency-based or Laser-Wake-Field ones.Comment: File RevTex, 12 pages, 8 figure

Analysis of the Seismic Risk of Major-Hazard Industrial Plants and Applicability of Innovative Seismic Protection Systems

In this paper the main results obtained within different research projects, developed about the applicability of seismic passive control of major-hazard industrial installations are shown. The work concerns the main components of a refinery that have been classified and collected into a limited number of classes on the basis of the geometrical and mechanical characteristics. For each class, the main damages caused by past earthquakes have been described and the most vulnerable component have been identified. Finally, a synthesis of the effects of earthquakes on the different typology of process components has been carried out and the most suitable innovative seismic protection systems, in particular of passive type, have been recognized. Finally an example of using dissipative coupling between a distillation column and an adjacent service frame is illustrated

Hydrodynamic impacts of short laser pulses on plasmas

We determine conditions allowing to simplify the description of the impact of a short and arbitrarily intense laser pulse onto a cold plasma at rest. If both the initial plasma density and pulse profile have plane simmetry, then suitable matched upper bounds on the maximum and the relative variations of the initial density, as well as the intensity and duration of the pulse, ensure a strictly hydrodynamic evolution of the electron fluid (without wave-breaking or vacuum-heating) during its whole interaction with the pulse, while ions can be regarded as immobile. We use a recently developed fully relativistic plane model whereby the system of the (Lorentz-Maxwell and continuity) PDEs is reduced into a family of highly nonlinear but decoupled systems of non-autonomous Hamilton equations with one degree of freedom, with the light-like coordinate $\xi=ct\!-\!z$ instead of time $t$ as an independent variable, and new apriori estimates (eased by use of a Liapunov function) of the solutions in terms of the input data (initial density and pulse profile). If the laser spot radius $R$ is finite but not too small the same conclusions hold for the part of the plasma close to the axis $\vec{z}$ of cylindrical symmetry. These results may help in drastically simplifying the study of extreme acceleration mechanisms of electrons.Comment: 29 pages, 8 figures. To appear in the Journal "Mathematics

Alkylation of methyl linoleate with propene in ionic liquids in the presence of metal salts

Vegetable oils and fatty acid esters are suitable precursor molecules for the production of a variety of bio-based products and materials, such as paints and coatings, plastics, soaps, lubricants, cosmetics, pharmaceuticals, printing inks, surfactants, and biofuels. Here, we report the possibility of using Lewis acidic ionic liquids (ILs) to obtain polyunsaturated ester dimerization-oligomerization and/or, in the presence of another terminal alkene (propene), co-polymerization. In particular, we have tested the Lewis acidic mixtures arising from the addition of a proper amount of GaCl3 (X > 0.5) to two chloride-based (1-butyl-3-methylimidazolium chloride, [bmim]Cl, and 1-butylisoquinolium chloride, [BuIsoq]Cl) or by dissolution of a smaller amount of Al(Tf2N)3 (X = 0.1) in 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, [bmim][Tf2N]. On the basis of product distribution studies, [bmim][Tf2N]/Al(Tf2N)3 appears the most suitable medium in which methyl linoleate alkylation with propene can compete with methyl linoleate or propene oligomerization

Perspectives of Italian pregnant women on pregnancy examinations and pregnancy care

Airn: Assessing awareness of Italian low-risk pregnant patients on low-risk pregnancy care and what do they feel about their own pregnancy Methods: A questionnaire was administered to 382 low-risk pregnant women. This questionnaire assessed generai knowledge of low-risk pregnancy, low-risk pregnancy care, and how much patients rated ten topics of low-risk pregnancy care. It would be expected that the knowledge of each topic would associates with the patient's perceived importance of that topic. Resulis: Poor knowledge of pregnancy care was proven. Patients seem to incorrectly overrate vaginal examinations and obstetric and gynecologist-led care, whi!e they attribute appropriate importance to midwife-led care. The more exami-nations performed (vaginal examinations, sonographic checks, cardiotocographies), the higher their rating. Conclusions: In Italy, expectations of pregnant women about their own pregnancy are incorrectly trusted in the obstetrics and gynecologists. Both poor knowledge of pregnancy care and cultural perspectives on the birth process amongst Italian people explain the finding. Referring low-risk pregnant women to midwivcs would help them to rate more the care than the caregiver. (www.actabiomedica.it

Effect of the αs1-casein genotype and its interaction with diet degradability on milk production, milk quality, metabolic and endocrinal response of Girgentana goats

We studied interaction between diet degradability and genotype at CSN1S1 locus in lactating goats.•We evaluated productive, metabolic and hormonal response of goats at different αs1-casein genotype.•Little effect of diet degradability and interaction with genotype on production and quality.•Higher milk yield, casein percentage and lower urea in goats with strong alleles at CSN1S1 locus.•Higher tyroid hormones in goats with strong alleles

Theoretical Investigations of the Effects of J-Aggregation on the Linear and Nonlinear Optical Properties of E-4-(4-Dimethylaminostyryl)-1-methylpyridinium [DAMS + ]

J-type aggregation of organic chromophores into inorganic host matrixes provides a useful route toward materials showing strong second-order nonlinear optical (NLO) response. The increased NLO response of J-aggregates is related to the peculiar arrangement of the NLO-phores into the host matrix, which produces the appearance of a narrow and intense band in the material electronic absorption spectrum, red-shifted with respect to the main absorption band of the isolated NLO-phore. A theoretical investigation, based on DFT, TDDFT, and ZINDO calculations on the relationship between the structural features of various or oligomeric aggregates and their linear and nonlinear optical properties shows that the appearance of a new red-shifted absorption band, typical of J-aggregation, is associated with interchromophoric transitions of charge-transfer character, due to the splitting of HOMO and LUMO levels. The intensity of this latter band increases by increasing the number of NLO-phores in a model of oligomeric arrangement of J-aggregates. The calculated quadratic hyperpolarizabilities for the mostly responsive J-type trimeric aggregates of [DAMS + ] are found to largely exceed that of three isolated NLO-phores, confirming a cooperative NLO strong contribution due to J-aggregation. Finally, our DFT and TDDFT calculations on eclipsed or with opposite dipole dimeric H-aggregates of [DAMS + ] show a splitting of HOMO and LUMO levels, which gives place to interchromophoric transitions of chargetransfer character but blue-shifted, as observed experimentally

Validation of the 3-variable prognostic score (3-PS) in mCRPC patients treated with 223 Radium-dichloride: a national multicenter study

Objective: Radium-223 (223Ra) has been approved for treatment in patients with metastatic castration-resistant prostatic cancer (mCRPC) and bone metastasis. This α-emitting radionuclide has a beneficial effect on pain and is also capable to increase overall survival (OS). Several studies evaluated the prognostic value of different biomarkers at baseline, such as serum values, imaging parameters or pain. To date, however, clinicians lack a validated and simple system to assess which patients will most likely benefit from 223Ra treatment. The 3-variable prognostic score (3-PS), proposed in a single-center study in 2017 classifies patients in five prognostic groups with a specific OS. This study aims to validate the 3-PS in a larger multicenter population. Methods: Four hundred and thirty mCRPC patients treated with 223Ra from six different centers were analyzed. The 3-PS score consists of the collection of baseline hemoglobin, prostatic specific antigen and Eastern cooperative oncology group performance status and was initially applied to the whole population (total group). The score was then validated on the 338 patient's subgroup (clean group) obtained by subtracting the 92 patients enrolled for the original study of the 3-PS score. This purified group served as further validation evidence. Results: Statistical analysis showed that the 3-PS score was valid on the total group as well as in the clean group as the AUC estimated (0.74) falls within the CI of the AUC calculated on the validation sample (95% CI 0.66-0.82). Conclusion: This study confirms the validity of the 3-PS score for mCRPC patients. This score is simple, noninvasive and affordable and can be easily used to select patients that will most probably complete 223Ra treatment. In addition, this tool provides an exact estimate of life expectancy in terms of OS

Pengaruh Kuat Arus Dan Waktu Pengelasan Pada Proses Las Titik (Spot Welding) Terhadap Kekuatan Tarik Dan Mikrostuktur Hasil Las Dari Baja Fasa Ganda (Feritte-Martensite)

This research was conducted to investigate the appropiate spot welding variable to get the maximum tensile strength. The highest of tensile strength referred as good quality of weldment.The plate was made from low carbon steel with phase ferrite and martensite. The current of welding used 0.9 kA, 1.6 kA, dan 1.85 kA with welding time were 0.25, 0.5 , 0.75 and 1 second. Mechanical properties testing done involved tensile strength to know shear strength of weld joint. Microstructure test used optical microscope.The results show that spot welding with thecurrent of 1.85kA and welding time of 1 second has the highest tensile strength (about 237.04N/mm2). On the other hand, the lowest tensile strength (150 N/mm2) was produced by combination of 0.9 kA and 0.25 second welding time. It was caused by recrystallization phasedeformation on steel