376 research outputs found
Intermodal vs. conventional logistic of refrigerated products: a case study from Southern to Northern Europe
Most of perishable goods, such as fruit and vegetables, are transported in Europe by truck and clogging up the main road networks. The increasing demand for freight transport and the environmental concerns all indicate the necessity to embrace new means of transport such as the intermodal one. The intermodal transport uses swap bodies and reefer containers that allow for the use of interchangeable truck, train, and ship to reduce direct and external costs. Nowadays, the utilization of exclusive truck transport is due to its considerable flexibility and often to the disregard of the motor vehicle regulations during transport. This research aims to analyze some essential readjustments that must be made in order to increase efficiency in the logistic of refrigerated fruit and vegetables. To do so, some hypotheses were analyzed and formulated in which the strategic use of the truck was recognized and inserted as part of an intermodal transport system. The transport options of a combined use of ships and trains in association with trucks were evaluated with respect to the current prevalent solution of exclusive use of trucks. Such options were evaluated by comparing them under different itineraries hypotheses (from south Italy, Sicily to Germany, Munich) on the base of costs and transit-times parameters. This was done mainly throughout interviewing sector-relevant transport operators. The results of the comparison between the intermodal and conventional transport was shown to be economically more convenient with respect to both legal and illegal transport by exclusive truck transport, presenting lower per unit costs (swap body or semi-trailer, containing the same amount of goods). Moreover, the intermodal solution scores equal or higher transit times in the comparison with the “transit by regulation compliance” and much higher transit times if compared with the “illegal” option. Therefore, the regulation compliance aspect would partially promote the use of intermodal options in a future fair competition. In addition, besides reducing the direct costs, it produces several other positive effects in terms of external costs to the society such as to reduce road crashes, noises, atmospheric emissions and greenhouse effect. A more efficient system should plan an integrated system of arrival and departure organizing together the schedules of ships and trains dedicated to perishable goods and increasing the transported amounts. Furthermore, another idea is to stipulate commercial agreements with train operators, applying a reduction on the base price, by ensuring the delivery of a block train for an arranged period. Keywords: Intermodal, freight logisticcentre, truck haulage, rail hub; terminal
Definition of Cytotoxic, Antioxidant and Heavy Metals Activity of Tomatoes Grown in Toxic Muddy Soils
Nonadiabatic charged spherical gravitational collapse
We present a complete set of the equations and matching conditions required
for the description of physically meaningful charged, dissipative, spherically
symmetric gravitational collapse with shear. Dissipation is described with both
free-streaming and diffusion approximations. The effects of viscosity are also
taken into account. The roles of different terms in the dynamical equation are
analyzed in detail. The dynamical equation is coupled to a causal transport
equation in the context of Israel-Stewart theory. The decrease of the inertial
mass density of the fluid, by a factor which depends on its internal
thermodynamic state, is reobtained, with the viscosity terms included. In
accordance with the equivalence principle, the same decrease factor is obtained
for the gravitational force term. The effect of the electric charge on the
relation between the Weyl tensor and the inhomogeneity of energy density is
discussed.Comment: 23 pages, Latex. To appear in Phys. Rev. D. Some references correcte
Diagnosis and treatment of pulmonary embolism: a multidisciplinary approach
The diagnosis of pulmonary embolism (PE) is frequently considered in patients presenting to the emergency department or when hospitalized. Although early treatment is highly effective, PE is underdiagnosed and, therefore, the disease remains a major health problem. Since symptoms and signs are non specific and the consequences of anticoagulant treatment are considerable, objective tests to either establish or refute the diagnosis have become a standard of care. Diagnostic strategy should be based on clinical evaluation of the probability of PE. The accuracy of diagnostic tests for PE are high when the results are concordant with the clinical assessment. Additional testing is necessary when the test results are inconsistent with clinical probability. The present review article represents the consensus-based recommendations of the Interdisciplinary Association for Research in Lung Disease (AIMAR) multidisciplinary Task Force for diagnosis and treatment of PE. The aim of this review is to provide clinicians a practical diagnostic and therapeutic management approach using evidence from the literature. © 2013 Lavorini et al
The combined use of cross-section analysis and other stratigraphic recording systems in the cleaning of two panel paintings from the fifteenth- and sixteenth-century
Cross sections are frequently used in the stratigraphic study of pictorial structures. Thanks to cross sections, it is possible to study and record original and non-original strata that may provide important information regarding the artist's technique and later restoration processes. This information helps conservators design different strategies in processes such as cleaning. However, it is often in cleaning where the advantages and limitations of cross sections become obvious. When dealing with a complex structure, cross sections may not be enough to record in a comprehensive and accurate manner all the strata removed during cleaning. In some cases, the conservator may obtain during cleaning a great amount of stratigraphic information that is not visible in the cross sections. Therefore, it may be necessary to resort to other recording systems, such as the stratigraphic unit recording sheet and the stratigraphic diagram, which are frequently used in archaeological stratigraphy. This article demonstrates how cross-section analysis was combined with stratigraphic study during the cleaning of two panel paintings to gain an improved understanding of their complicated layer structure.Barros García, JM.; Reina De La Torre, A.; Pérez Marín, E. (2014). The combined use of cross-section analysis and other stratigraphic recording systems in the cleaning of two panel paintings from the fifteenth- and sixteenth-century. Studies in Conservation. 60(4):245-252. doi:10.1179/2047058414Y.0000000128S24525260
New Results on Holographic Three-Point Functions
We exploit a gauge invariant approach for the analysis of the equations
governing the dynamics of active scalar fluctuations coupled to the
fluctuations of the metric along holographic RG flows. In the present approach,
a second order ODE for the active scalar emerges rather simply and makes it
possible to use the Green's function method to deal with (quadratic)
interaction terms. We thus fill a gap for active scalar operators, whose
three-point functions have been inaccessible so far, and derive a general,
explicitly Bose symmetric formula thereof. As an application we compute the
relevant three-point function along the GPPZ flow and extract the irreducible
trilinear couplings of the corresponding superglueballs by amputating the
external legs on-shell.Comment: v2: reference added, typos corrected v3: sign convention for
background changed, agrees with version published in JHE
The ovary of the bignose fanskate Sympterygia acuta Garman, 1877 (Chondrichthyes, Rajidae) in the Bahía Blanca estuary, Argentina: morphology and reproductive features
The Raychaudhuri equations: a brief review
We present a brief review on the Raychaudhuri equations. Beginning with a
summary of the essential features of the original article by Raychaudhuri and
subsequent work of numerous authors, we move on to a discussion of the
equations in the context of alternate non--Riemannian spacetimes as well as
other theories of gravity, with a special mention on the equations in
spacetimes with torsion (Einstein--Cartan--Sciama--Kibble theory). Finally, we
give an overview of some recent applications of these equations in General
Relativity, Quantum Field Theory, String Theory and the theory of relativisitic
membranes. We conclude with a summary and provide our own perspectives on
directions of future research.Comment: 35 pages, two figures, to appear in the special issue of Pramana
dedicated to the memory of A. K. Raychaudhur
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