297 research outputs found

    Variables influencing transport mode choice: a generalized cots approach

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    The decision variables that influence transport mode choice are numerous. From a careful appraisal of the literature review it appears that two main typologies of variables can be identified: costs related to the transport of the goods and other service’s attributes that play a crucial role in the selection. Each of these two categories has been already revised in previous researches and some fundamental findings are reported in this paper as a preliminary base for the development of the present study. The analysis of the literature review will revise the internal costs variables, or out of pocket money, and the influence of qualitative attributes as decision variables. The paper will conclude with a review of the external costs and their hypothetical internalization in the calculation of transport cost. The paper will be organized as follows: a literature review on elements affecting mode choice, the third paragraph will deal with the methodological approach of generalized cost function that will be applied in paragraph four on the selected corridors. Some conclusions and further recommendations for research will terminate the paper.Intermodal transport, Generalized costs, External cost

    Statistical study of axial rotation in a type stars with new determination of v sin i

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    We have observed all A type stars of the southern hemisphere brighter than 6.5 mag in order to perform statistical studies of axial rotation. The spectra were obtained at the 2.15 m telescope at CASLEO. We have used the method of Diaz et al. (2011) to calculate axial rotation velocities.Fil: Grosso, Monica Gladys. Consejo Nacional de Investigaciones Cientiâ­ficas y Tecnicas. Centro Cientifico Tecnologico San Juan. Instituto de Ciencias Astronomicas de la Tierra y del Espacio; Argentina. Universidad Nacional de San Juan; ArgentinaFil: Levato, Orlando Hugo. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico San Juan. Instituto de Ciencias Astronomicas de la Tierra y del Espacio; Argentina. Universidad Nacional de San Juan; Argentin

    What information do shoppers share? The effect of personnel-, retailer-, and country-trust on willingness to share information

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    The relationship between consumers' privacy concerns and their willingness to disclose personal information to retailers is more complex than a simple negative one. The multi-faced context, within which privacy decisions take place, shapes and bounds this relationship. Drawing on privacy contextual integrity theory, we model the privacy decisions as influenced by individuals' multilevel trusting surroundings, which include trust in a retailer and in its personnel at the micro-level, and trust in a country at the macro-level. Based on 22,050 survey data across seven product categories in fourteen countries, our Bayesian multilevel modeling reveals that micro- and macro-level trust may promote consumers' disclosure intentions via three mechanisms: (1) micro-level trust positive effect on consumers' willingness to disclose their data; (2) micro-level trust effect by attenuating privacy concerns' negative influence on this willingness; and (3) the positive indirect effect of trust in the country on both the direct and indirect impacts of trust in a retailer and in its personnel. Interestingly, trust's direct effects are found in all the investigated types of information (i.e., identification, medical, financial, locational, demographic, lifestyle, and media usage data), whereas the indirect effects are found to vary across information types. Our post-hoc cluster analysis shows that different retail contexts can be classified into three clusters and help retailers understand whether they should invest in developing both trust in their retail company and in their personnel, or mainly on one of the two. By taking different types of trust and context effects into consideration, our findings help different retailers encourage customers to disclose their data with them. (C) 2020 New York University. Published by Elsevier Inc. All rights reserved

    Rotational velocities of B stars

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    We measured the projected rotational velocities of 1092 northern B stars listed in the Bright Star Catalogue (BSC) and calibrated them against the 1975 Slettebak et al. system. We found that the published values of B dwarfs in the BSC average 27% higher than those standards. Only 0.3% of the stars have rotational velocities in excess of two-thirds of the breakup velocities, and the mean velocity is only 25% of breakup, implying that impending breakup is not a significant factor in reducing rotational velocities. For the B8-B9.5 III-V stars the bimodal distribution in V can be explained by a set of slowly rotating Ap stars and a set of rapidly rotating normal stars. For the B0-B5 III-V stars that include very few peculiar stars, the distributions in Fare not bimodal. Are the low rotational velocities of B stars due to the occurrence of frequent low-mass companions, planets, or disks? The rotational velocities of giants originating from late B dwarfs are consistent with their conservation of angular momentum in shells. However, we are puzzled by why the giants that originate from the early B dwarfs, despite having 3 times greater radii, have nearly the same rotational velocities. We find that all B-type primaries in binaries with periods less than 2.4 days have synchronized rotational and orbital motions; those with periods between 2.4 and 5.0 days are rotating within a factor 2 of synchronization or are "nearly synchronized." The corresponding period ranges for A-type stars are 4.9 and 10.5 days, or twice as large. We found that the rotational velocities of the primaries are synchronized earlier than their orbits are circularized. The maximum orbital period for circularized B binaries is 1.5 days and for A binaries is 2.5 days. For stars of various ages from 107.5 to 1010.2 yr the maximum circularized periods are a smooth exponential function of age.Fil: Abt, Helmut A.. Kitt Peak National Observatory; Estados UnidosFil: Levato, Orlando Hugo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Complejo Astronómico "El Leoncito". Universidad Nacional de Córdoba. Complejo Astronómico "El Leoncito". Universidad Nacional de la Plata. Complejo Astronómico "El Leoncito". Universidad Nacional de San Juan. Complejo Astronómico "El Leoncito"; ArgentinaFil: Grosso, Monica Gladys. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Complejo Astronómico "El Leoncito". Universidad Nacional de Córdoba. Complejo Astronómico "El Leoncito". Universidad Nacional de la Plata. Complejo Astronómico "El Leoncito". Universidad Nacional de San Juan. Complejo Astronómico "El Leoncito"; Argentin

    switching from intravenous to subcutaneous formulation of abatacept different results in a series of 21 patients

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    To the Editor: We read with interest the article by Reggia, et al 1, a monocentric study analyzing the efficacy and safety of switching from intravenous (IV) to subcutaneous (SC) formulation of abatacept (ABA) in patients with rheumatoid arthritis. The authors report a relatively high risk of disease relapse (27%) occurring in a mean of 11 weeks after switching to SC administration. The study did not find any significant predictive factor for a switch failure. The concern that patients with a higher body mass index could receive lower cumulative doses compared to weight-tiered monthly infusions, leading to a significant influence on treatment efficacy, was not confirmed by this study, or by previous dose-finding trials and … Address correspondence to Dr. S. Monti; E-mail: sara.saramonti{at}gmail.co

    Properties of galactic B[e] supergiants: II. HDE 327083

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    The emission-line object HDE 327083 has long been considered to be one of the most luminous stars in the Milky Way. Nevertheless, no reliable physical parameters have been published for it. Our high-resolution optical spectroscopy revealed the presence of photospheric lines of a cool luminous companion. We detected significant antiphased radial velocity variations of the emission and absorption lines. The data obtained are still insufficient to derive a reliable orbital solution; however, the orbital period is most likely of the order of 6 months. We conclude that HDE 327083 is a binary system consisting of an early B-type primary and early F-type secondary, with luminosities log L/L⊙ = 5.0 ± 0.4 and 4.2 ± 0.4, respectively, and whose orbital plane is viewed nearly edge-on. We also obtained new multicolour optical and infrared photometry of HDE 327083. From both the photometric and spectroscopic data, we found that the system is located at a distance of 1.5 ± 0.5 kpc. Most of the circumstellar gas seems to be orbiting the primary and is distributed in a mildly flattened envelope with a height scale and velocity decreasing outward from the star. We suggest that HDE 327083 represents an advanced evolutionary stage of a β Lyrae type binary.Fil: Miroshnichenko, A. S.. Russian Academy of Sciences at Pulkovo; Rusia. University of Toledo; Estados UnidosFil: Levato, Orlando Hugo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Complejo Astronómico "El Leoncito". Universidad Nacional de Córdoba. Complejo Astronómico "El Leoncito". Universidad Nacional de la Plata. Complejo Astronómico "El Leoncito". Universidad Nacional de San Juan. Complejo Astronómico "El Leoncito"; ArgentinaFil: Bjorkman, K. S.. University of Toledo; Estados UnidosFil: Grosso, Monica Gladys. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Complejo Astronómico "El Leoncito". Universidad Nacional de Córdoba. Complejo Astronómico "El Leoncito". Universidad Nacional de la Plata. Complejo Astronómico "El Leoncito". Universidad Nacional de San Juan. Complejo Astronómico "El Leoncito"; Argentin

    Spectroscopic binaries in southern open clusters

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    This is a report on an ongoing program about binaries in southern open clusters. The long-term purpose of this project is to contribute to understanding the formation and evolution of spectroscopic binaries, providing observational constraints that will permit tests of some of the current theories on binary formation in open clusters.This is a report on an ongoing program about binaries in southern open clusters. The long-term purpose of this project is to contribute to understanding the formation and evolution of spectroscopic binaries, providing observational constraints that will permit tests of some of the current theories on binary formation in open clusters.Fil: Levato, Orlando Hugo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Complejo Astronómico "El Leoncito". Universidad Nacional de Córdoba. Complejo Astronómico "El Leoncito". Universidad Nacional de la Plata. Complejo Astronómico "El Leoncito". Universidad Nacional de San Juan. Complejo Astronómico "El Leoncito"; ArgentinaFil: González, J. F.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Complejo Astronómico "El Leoncito". Universidad Nacional de Córdoba. Complejo Astronómico "El Leoncito". Universidad Nacional de la Plata. Complejo Astronómico "El Leoncito". Universidad Nacional de San Juan. Complejo Astronómico "El Leoncito"; ArgentinaFil: Malaroda, Stella Maris. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Complejo Astronómico "El Leoncito". Universidad Nacional de Córdoba. Complejo Astronómico "El Leoncito". Universidad Nacional de la Plata. Complejo Astronómico "El Leoncito". Universidad Nacional de San Juan. Complejo Astronómico "El Leoncito"; ArgentinaFil: Grosso, Monica Gladys. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Instituto de Ciencias Astronómicas, de la Tierra y del Espacio. Universidad Nacional de San Juan. Instituto de Ciencias Astronómicas, de la Tierra y del Espacio; Argentin

    Spectroscopy of B-type emission-line stars with compact dusty envelopes: HD 85567, Hen 3-140, and Hen 3-1398

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    We report the results of our spectroscopic observations (3600-5900 Å, R ≃ 16000 and 5750-8750 Å, R ≃ 11000) of three southern emission-line B-type stars associated with IRAS sources, HD 85567, Hen 3-140, and Hen 3-1398, whose nature and evolutionary state are not well-established yet. We also obtained new multicolour photometry of HD 85567 (UBV(RI)cJHKL) and (JHKLM). A large near-IR excess is found in Hen 3-140 for the first time. All three objects show double-peaked Fe II lines in emission. The Balmer emission lines are double-peaked in HD 85567 and Hen 3-140, while the He I lines are found in absorption. Hen 3-1398 displays triple-peaked Balmer lines as well as single-peaked He I and He II lines in emission. Fundamental parameters of the stars are estimated on the basis of both photometric and spectroscopic data. The whole set of their properties resemble that of a recently defined group of Be stars with warm dust (Sheikina et al. 2000).Fil: Miroshnichenko, A. S.. Russian Academy of Sciences at Pulkovo; Rusia. University Of Toledo (utoledo); Estados UnidosFil: Levato, Orlando Hugo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Complejo Astronómico "El Leoncito". Universidad Nacional de Córdoba. Complejo Astronómico "El Leoncito". Universidad Nacional de la Plata. Complejo Astronómico "El Leoncito". Universidad Nacional de San Juan. Complejo Astronómico "El Leoncito"; ArgentinaFil: Bjorkman, K. S.. University Of Toledo (utoledo); Estados UnidosFil: Grosso, Monica Gladys. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Complejo Astronómico "El Leoncito". Universidad Nacional de Córdoba. Complejo Astronómico "El Leoncito". Universidad Nacional de la Plata. Complejo Astronómico "El Leoncito". Universidad Nacional de San Juan. Complejo Astronómico "El Leoncito"; Argentin

    Spectral morphology and rotation in the open cluster NGC 6025

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    Hemos clasificado espectralmente a los probables miembros más brillantes del cúmulo abierto NGC 6025 y hemos calculado sus velocidades de rotación. Encontramos un módulo de distancia de 9.80±0.06 (error probable) y derivamos una edad de 84 millones de años para este cúmulo. La estrella más brillante de NGC 6025, HD 143448 fue clasificada como B1Ve y es una estrella azul desubicada (blue straggler) tal como fue propuesto por otros autores (ver Mermilliod 1982). Hemos encontrado tres estrellas peculiares (dos de Si y una de Hg–Mn?) y dos binarias de dos espectros, una de ellas previamente estudiada pero probablemente no miembro del cúmulo. Otra estrella del campo tiene emisión, pero probablemente tampoco es miembro del cúmulo. El promedio de la rotación axial para los miembros de este cúmulo es 73% del promedio de rotación de las estrellas de campo de igual temperatura.We have performed spectral classification and measurements of the axial rotation velocity for the brightest stars in the region of the open cluster NGC 6025. A distance modulus of 9.80 ± 0.06 (pe) and an age of 84 million years were derived. The brightest star of the cluster, HD 143448 was classified as B1Ve and it is a blue straggler as proposed by other authors (see Mermilliod 1982). We found three peculiar stars (two Si and one Hg–Mn?). Another star in the field shows emission but is probably a non–member. We also found two SB2 binaries. The average axial rotation for the cluster members seems to be 73% of the average rotation of the field stars with the same temperature.Fil: Grosso, Monica Gladys. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Instituto de Ciencias Astronómicas, de la Tierra y del Espacio. Universidad Nacional de San Juan. Instituto de Ciencias Astronómicas, de la Tierra y del Espacio; ArgentinaFil: Levato, Orlando Hugo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Instituto de Ciencias Astronómicas, de la Tierra y del Espacio. Universidad Nacional de San Juan. Instituto de Ciencias Astronómicas, de la Tierra y del Espacio; Argentin
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