Nonequilibrium electron energy distribution in Au under subpicosecond laser irradiation: A kinetic study

We have performed a kinetic study of the electron dynamic relaxation inside a Au film subjected to a subpicosecond laser pulse. For this purpose, we have developed a time-dependent numerical solution of the Boltzmann equation for the electrons inside the film considering the collision integrals due to electron–electron and electron–phonon collisions and a perturbation term due to the laser pulse. Our results show that, after the pulse excitation, electron distributions are very far from equilibrium. Therefore it is not possible, especially in the first part of the temporal evolution, to describe the relaxation of the electron distribution through a two-temperature model

Reduced Two-Level Approach for Air Kinetics in Recombination Regime

Abstract. The possibility of using reduced model, that account for non-Boltzmann vibrational distributions for nitrogen monoxide kinetics has been explored. The basic idea is that the rate coefficients, which are proportional to the tail of the vibrational distribution function, are strictly correlated to reactant density rather than to vibrational temperature, which depend on the low energy distribution. The model consider the rate coefficients as a function of the population of the last vibrational level of the relevant species, which evolution is calculated with a proper kinetic equation

Sulfate Reducing Bacteria as Bio-cleaning Agents: Development of New Methodologies and Study Cases

In the last decades, the contribution of different scientific disciplines in the field of restoration and conservation of cultural heritage to finding alternative methods of investigation that are even more effective and fully respect artworks, operators and environment, has greatly increased. An example is the University of Milan patent that provides for the use of some specialized bacteria as cleaning agents. This method, known as biocleaning, is based on the use of Desulfovibrio vulgaris, a sulfate reducing bacterium, for the removal of sulfate alterations from stone surfaces. Recently, the university spin-off Micro4yoU purchased the patent by initiating a series of investments aimed at enhancing the commercial product from prototype. The present work describes: the desulfation mechanism operated by Desulfovibrio vulgaris and the technological shift necessary to obtain a biological formulation usable in situ, with two practical case studies

Sulfate Reducing Bacteria as Bio-cleaning Agents: Development of New Methodologies and Study Cases

In the last decades, the contribution of different scientific disciplines in the field of restoration and conservation of cultural heritage to finding alternative methods of investigation that are even more effective and fully respect artworks, operators and environment, has greatly increased.An example is the University of Milan patent that provides for the use of some specialized bacteria as cleaning agents. This method, known as biocleaning, is based on the use of Desulfovibrio vulgaris, a sulfate reducing bacterium, for the removal of sulfate alterations from stone surfaces.Recently, the university spin-off Micro4yoU purchased the patent by initiating a series of investments aimed at enhancing the commercial product from prototype. The present work describes: the desulfation mechanism operated by Desulfovibrio vulgaris and the technological shift necessary to obtain a biological formulation usable in situ, with two practical case studies.Negli ultimi decenni è cresciuto il contributo che le diverse discipline scientifiche hanno dato al recupero e alla conservazione del patrimonio artistico per trovare soluzioni sempre più efficaci e rispettose del bene, dell’operatore e dell’ambiente.Un esempio è un brevetto sviluppato dall’Università degli studi di Milano che prevede l’utilizzo di alcuni specifici batteri come agenti di pulitura. Tale metodo, indicato col termine di bio-pulitura propone, tra gli altri, l’impiego del batterio solfato riduttore Desulfovibrio vulgaris per la rimozione di alterazioni solfatiche da superfici litoidi. Recentemente, il brevetto è stato acquisito dallo spin-off universitario Micro4yoU che ha avviato una serie di investimenti per sviluppare, a partire dal prototipo di laboratorio, un prodotto commerciale.Nel presente lavoro verranno illustrati: il meccanismo di desolfatazione ad opera di Desulfovibrio vulgaris, il processo di trasferimento tecnologico affrontato per ottenere un formulato microbico utilizzabile in cantiere e due casi studio applicativi

Using the collaborative intervention planning framework to adapt a health-care manager intervention to a new population and provider group to improve the health of people with serious mental illness

Background: Health-care manager interventions improve the physical health of people with serious mental illness (SMI) and could be widely implemented in public mental health clinics. Local adaptations and customization may be needed to increase the reach of these interventions in the public mental health system and across different racial and ethnic communities. In this study, we describe how we used the collaborative intervention planning framework to customize an existing health-care manager intervention to a new patient population (Hispanics with SMI) and provider group (social workers) to increase its fit with our local community. Methods: The study was conducted in partnership with a public mental health clinic that serves predominantly Hispanic clients. A community advisory board (CAB) composed of researchers and potential implementers (e.g., social workers, primary care physicians) used the collaborative intervention planning framework, an approach that combines community-based participatory research principles and intervention mapping (IM) procedures, to inform intervention adaptations. Results: The adaptation process included four steps: fostering collaborations between CAB members; understanding the needs of the local population through a mixed-methods needs assessment, literature reviews, and group discussions; reviewing intervention objectives to identify targets for adaptation; and developing the adapted intervention. The application of this approach enabled the CAB to identify a series of cultural and provider level-adaptations without compromising the core elements of the original health-care manager intervention. Conclusions: Reducing health disparities in people with SMI requires community engagement, particularly when preparing existing interventions to be used with new communities, provider groups, and practice settings. Our study illustrates one approach that can be used to involve community stakeholders in the intervention adaptation process from the very beginning to enhance the transportability of a health-care manager intervention in order to improve the health of people with SMI

Implementation of a Weight Loss Program for Latino Outpatients with Severe Mental Illness

To determine feasibility of implementation of a weight loss program for overweight Latinos with severe mental illness. In this quasi-experimental study, a 14-week behavioral weight loss course (extended) was implemented at one clinic. A one-time nutrition class (brief) was given at a sister clinic. Implementation feasibility was assessed by consent and participation rates. Weight was followed for 6 months. Consent rates were high [77 % (49/64) extended; 68 % (39/57) brief], and 88 % (43/49) of extended subjects participated and 88 % (38/43) completed follow-up. Weight loss did not differ between groups. A behavioral weight loss course is feasible to implement for this population

“Oxidation of Natural Targets by Dioxiranes. 6.On the Direct Regio- and Siteselective Oxyfunctionalization of Estrone and of 5α-Androstane Steroid Derivatives.”

Using methyl(trifluoromethyl)dioxirane (1b), 3b,6a,17b-triacetoxy-5a-androstane (6) could be selectively transformed into its C-14 hydroxy derivative (7) and into the valuable C-12 ketone steroid (8), in high yields under mild reaction conditions. Similarly, the oxidation of 3a-estrone acetate (4) with 1b was carried out to yield selectively the steroid C-9 hydroxy derivative (5). The high regio- and siteselectivity attained demonstrates that the powerful dioxirane 1b is the reagent of choice to synthesize valuable oxyfunctionalized steroid derivatives

Vibrational kinetics of electronically excited states in H

The evolution of atmospheric pressure hydrogen plasma under the action of repetitively ns electrical pulse has been investigated using a 0D state-to-state kinetic model that self-consistently couples the master equation of heavy particles and the Boltzmann equation for free electrons. The kinetic model includes, together with atomic hydrogen states and the vibrational kinetics of H2 ground state, vibrational levels of singlet states, accounting for the collisional quenching, having a relevant role because of the high pressure. The mechanisms of excitations, radiative decay and collisional quenching involving the excited H2 states and the corresponding cross sections, integrated over the non-equilibrium electron energy distribution function (EEDF) to obtain kinetic rates, are discussed in the light of the kinetic simulation results, i.e. the time evolution during the pulse of the plasma composition, of the EEDF and of the vibrational distributions of ground and singlet excited states

Elementary Processes and Kinetic Modeling for Hydrogen and Helium Plasmas

We report cross-sections and rate coefficients for excited states colliding with electrons, heavy particles and walls useful for the description of H 2 /He plasma kinetics under different conditions. In particular, the role of the rotational states in resonant vibrational excitations of the H 2 molecule by electron impact and the calculation of the related cross-sections are illustrated. The theoretical determination of the cross-section for the rovibrational energy exchange and dissociation of H 2 molecule, induced by He atom impact, by using the quasi-classical trajectory method is discussed. Recombination probabilities of H atoms on tungsten and graphite, relevant for the determination of the nascent vibrational distribution, are also presented. An example of a state-to-state plasma kinetic model for the description of shock waves operating in H 2 and He-H 2 mixtures is presented, emphasizing also the role of electronically-excited states in affecting the electron energy distribution function of free electrons. Finally, the thermodynamic properties and the electrical conductivity of non-ideal, high-density hydrogen plasma are finally discussed, in particular focusing on the pressure ionization phenomenon in high-pressure high-temperature plasmas