2,761 research outputs found

    Charge dynamics of a single donor coupled to a few electrons quantum dot in silicon

    Full text link
    We study the charge transfer dynamics between a silicon quantum dot and an individual phosphorous donor using the conduction through the quantum dot as a probe for the donor ionization state. We use a silicon n-MOSFET (metal oxide field effect transistor) biased near threshold in the SET regime with two side gates to control both the device conductance and the donor charge. Temperature and magnetic field independent tunneling time is measured. We measure the statistics of the transfer of electrons observed when the ground state D0 of the donor is aligned with the SET states

    Gender dimensions of the migration, sustainability and care nexus: The case study of the Mahanadi delta, India

    Get PDF
    Migration and environmental change are deeply interconnected processes, intimately linked to development pathways. The gender dimension of these complex interactions is often overlooked. Yet there are profound linkages and implications. This paper focuses on the gender division of labour to investigate how migration and environmental change relate to gender equality and sustainability. The study draws on research conducted in the Mahanadi delta, in the eastern Indian state of Odisha. In the Mahanadi delta labour migration is largely male dominated. Women remain behind in vulnerable environments facing social and economic challenges having impacts on their empowerment and wellbeing. The findings show shifts in work burden, as women often engage in new activities alongside the traditional domestic and social reproductive work but highlight differences across age and household headship. Firstly, this paper identifies the connections between gender, sustainability and care –conceptually and empirically. Secondly, it explores the gender division of labour in the study area by discussing its structural causes. Thirdly, it provides insights into migration dynamics and examines how they feed back into gender equality and sustainability. Finally, it argues for the need of integrated analytical approaches that reflect ecological and social-equity challenges. © 2021 The Author

    A few remarks on integral representation for zonal spherical functions on the symmetric space SU(N)/SO(N,R)SU(N)/SO(N,\R)

    Get PDF
    The integral representation on the orthogonal groups for zonal spherical functions on the symmetric space SU(N)/SO(N,R)SU(N)/SO(N,\R) is used to obtain a generating function for such functions. For the case N=3 the three-dimensional integral representation reduces to a one-dimensional one.Comment: Latex file, 10 pages, amssymb.sty require

    Analysis of the tautomeric equilibrium of two red monoazo dyes by UV–Visible, Raman and SERS spectroscopies

    Get PDF
    Acid Red 26 and Acid Red 18 are two early synthetic dyes belonging to the monazo dye class. The molecular structure of this class of dyes is characterized by the chromophoric azo group (N[dbnd]N) generally attached to benzene or naphthalene derivatives containing electron withdrawing and/or donating groups as substituents. As both red dyes have an OH group in ortho- position respect to the azo group, they undergo an azo-hydrazone tautomerism. In this work, UV–Vis, Raman and SERS spectroscopic analysis of the red dye solutions were carried out at different pH conditions, in order to evaluate the preponderance of one tautomer over the other as a function of the pH. Different experimental conditions were tested in order to find the best ones for the detection of both dyes. Thus, Raman spectra of the powder and aqueous solutions of AR26 and AR18 were obtained at the natural pH of the solutions, and above and below that value. The SERS analysis of the dye solutions were carried out at various pH values between 2 and 10, and with excitation at 442, 532 and 633 nm. The molecular structure and the theoretical Raman spectra of the two tautomers of both red dyes were calculated by DFT methods. The obtained results were used for the assignment of the Acid Red 26 and Acid Red 18 vibrational modes. Finally, a textile sample dyed with AR18 was analyzed by SERS

    PIXE and ToF-SIMS analysis of streaker samplers filters

    Get PDF
    This paper presents methodological innovations introduced in the characterisation of urban aerosol collected in Italy in a recent campaign. Two complementary ion beam analysis (IBA) techniques were used to analyse Nuclepore filters used in continuous streaker samplers to collect airborne particles in four Italian towns. Na to Pb elemental concentrations were obtained by particle induced X-ray emission (PIXE), while time of flight secondary ion mass spectrometry (ToF-SIMS) produced, on the same samples, time trends for several elements and molecular fragments. In addition, light attenuation measurements were used as a tracer for black carbon. The data produced by these three techniques was merged into a unique data set to address the characterisation of particulate matter sources. Correlations between elemental concentration trends (PIXE) and relative trends for molecular fragments (ToF-SIMS) and black carbon (light attenuation) have been studied by cluster and principal component analysis

    Ciao AI: the Italian adaptation and validation of the Chatbot Usability Scale

    Get PDF
    Chatbot-based tools are becoming pervasive in multiple domains from commercial websites to rehabilitation applications. Only recently, an eleven-item satisfaction inventory was developed (the ChatBot Usability Scale, BUS-11) to help designers in the assessment process of their systems. The BUS-11 has been validated in multiple contexts and languages, i.e., English, German, Dutch, and Spanish. This scale forms a solid platform enabling designers to rapidly assess chatbots both during and after the design process. The present work aims to adapt and validate the BUS-11 inventory in Italian. A total of 1360 questionnaires were collected which related to a total of 10 Italian chatbot-based systems using the BUS-11 inventory and also using the lite version of the Usability Metrics for User eXperience for convergent validity purposes. The Italian version of the BUS-11 was adapted in terms of the wording of one item, and a Multi-Group Confirmatory Factorial Analysis was performed to establish the factorial structure of the scale and compare the effects of the wording adaptation. Results indicate that the adapted Italian version of the scale matches the expected factorial structure of the original scale. The Italian BUS-11 is highly reliable (Cronbach alpha: 0.921), and it correlates to other measures of satisfaction (e.g., UMUX-Lite, τb = 0.67; p < .001) by also offering specific insights regarding the chatbots’ characteristics. The Italian BUS-11 can be confidently used by chatbot designers to assess the satisfaction of their users during formative or summative tests

    Deep eutectic solvents: green solvents for the removal of degraded gelatin on cellulose nitrate cinematographic films

    Get PDF
    Cellulose nitrate (CN) has been used in the past as support for photographic negatives and cinematographic films. This material is particularly unstable and can undergoes severe degradation due to thermal, photocatalytic and hydrolytic loss of nitro groups from the lateral chain. Thus, to prevent the disappearance of the movies, their scanning and digitalization become a priority. However, CN bases degradation may prevent the scanning of the films. The decrease in pH, for instance, lowers the viscosity of gelatin, which becomes softer. This causes the formation of gelatin residues which stick on the back of the superimposed frames inside the reels creating a deposit. Traditional approaches to clean gelatin residues from the surface of CN bases include the mechanical removal with scalpels and the use of organic solvents (such as isopropyl alcohol). However, these methods are either slow and ineffective or could potentially damage the degraded CN supports. To overcome these drawbacks, we have evaluated the performance of three choline chloride and betaine-based Deep Eutectic Solvent (DES) formulations as alternative for the removal of gelatine residues from CN supports. These solvents are inexpensive (when compared to traditional solvents), easy to prepare, green (non volatile, safe towards the operators and the environment, and potentially recyclable), non flammable and have been previously proposed for the extraction of proteinaceous materials, but their use for the restoration of photographic negatives or cinematographic films has not been reported yet. Selected areas over the frames of a real deteriorated CN cinematographic film were cleaned comparing the DES performances with the ones obtained using isopropyl alcohol as an example of a traditional method. In particular, the tested DES formulations showed superior cleaning power compared to isopropyl alcohol and, at the selected application times, resulted capable to remove the gelatin residues without affecting the CN film supports. Graphical abstract: [Figure not available: see fulltext.]

    An Easy Route to Enantiomerically Enriched 7- and 8-Hydroxystearic Acids by Olefin Metathesis - Based Approach

    Get PDF
    The synthesis of enantiomerically enriched 7- and 8-hydroxystearic acids (7- and 8-HSA) has been successfully accomplished starting from chiral non racemic 1-pentadecen-4-ol and 1-tetradecen-4-ol respectively. Their Yamaguchi\u2019s esterification with 4-pentenoic and 5-hexenoic acids respectively afforded the suitable dienic esters which were submitted to ring closing metathesis reaction. After hydrogenation and basic hydrolysis of the complex reaction mixture, chiral non racemic 7- and 8-HSA were obtained in about 40% total yield
    • …
    corecore