1,233 research outputs found

    A call to action: a stakeholder analysis of green logistics practices

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    Purpose: There is a growing body of literature discussing the green logistics practices (GLPs) that companies could introduce to reduce the logistics environmental impact. Current approaches also identify several influencing factors within firms that could serve as barriers to, or enablers of, GLPs. However, less is known about the role of extra-firm stakeholders, even though these are crucial to operationalizing green logistics effectively. This study merges current theoretical understanding with empirical evidence to provide a detailed stakeholder analysis of GLPs. Design/methodology/approach: Using stakeholder theory as a theoretical lens, the authors aimed at offering a mid-range contribution by conducting multiple embedded case studies examining Italian logistics service providers and shippers. GLPs and the related influencing factors were examined as sub-units of analysis within broader companies' environmental sustainability strategies. Findings: The authors identified cascading effects among factors influencing the adoption of GLPs (e.g. key economic factors are affected by external factors which also influence organizational and collaboration factors). These effects are moderated by interdependencies between primary and secondary stakeholders, and the study highlights the prominent involvement of secondary stakeholders, such as final consumers. Originality/value: This paper contributes to better understanding how and why companies adopt GLPs, emphasizing the wide set of stakeholders involved and illustrating how different stakeholders impact on GLPs adoption by affecting a set of influencing factors. By combining insights from the available literature with contemporary empirical data, the authors emphasize how Logistics Service Providers (LSPs) and shippers can no longer address the adoption of GLPs as “focal companies”, but only as part of a “focal network of interconnected stakeholders”, all of them influencing GLPs adoption

    Assessing the impact of smart lighting systems and on-site renewable generation in a distribution warehouse: a simulation-based approach

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    In the arena of logistics management, green warehousing has been achieving increasing attention from both practitioners and academia. On the one hand, practitioners – e.g., Logistics Service Providers (LSPs), manufacturers, and retailers – have been looking for solutions to decrease the environmental impact of their logistics facilities and incorporate measures towards greener warehousing processes. However, on the academic side, although a rising number of papers have been found addressing logistics sustainability, a need has emerged to focus on warehouses by analyzing the impact of the energy efficiency measures in place, and the related effects on warehouse consumption and environmental performance. This contribution aims at addressing this research gap. The paper proposes a simulation model based on DesignBuilder and EnergyPlus software and examines the impact of both interventions on the lighting systems and the introduction of on-site renewable generation in a distribution warehouse. Three different scenarios are proposed, and the related performance are examined in terms of consumption figures and CO2eq emissions. A discussion on the roadmap towards net-zero logistics facilities is offered, and streams for future investigation are highlighted

    Using the Sound Card as a Timer

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    Experiments in mechanics can often be timed by the sounds they produce. In such cases, digital audio recordings provide a simple way of measuring time intervals with an accuracy comparable to that of photogate timers. We illustrate this with an experiment in the physics of sports: to measure the speed of a hard-kicked soccer ball.Comment: 3 pages, 4 figures, Late

    Large scale Optimal Transportation Meshfree (OTM) Simulations of Hypervelocity Impact

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    Large scale three-dimensional numerical simulations of hypervelocity impact of Aluminum alloy 6061-T6 plates by Nylon 6/6 cylindrical projectile have been performed using the Optimal Transportation Meshfree (OTM) method of Li et al. [7] along with the seizing contact and variational material point failure algorithm [17, 18]. The dynamic response of the Al6061-T6 plate including phase transition in the high strain rate, high pressure and high temperature regime expected in our numerical analysis is described by the use of a variational thermomechanical coupling constitutive model with SESAME equation of state, rate-dependent J2 plasticity with power law hardening and thermal softening and temperature dependent Newtonian viscosity. A polytropic type of equation of state fit to in-house ReaxFF calculations is employed to model the Nylon 6/6 projectile under extreme conditions. The evaluation of the performance of the numerical model takes the form of a conventional validation analysis. In support of the analysis, we have conducted experiments over a range of plate thicknesses of [0.5, 3.0] mm, a range of impact velocities of [5.0, 7.0]km/s and a range of obliquities of [0, 70]° at Caltech's Small Particle Hypervelocity Range (SPHIR) Facility. Large scale three-dimensional OTM simulations of hypervelocity impact are performed on departmental class systems using a dynamic load balancing MPI/PThreads parallel implementation of the OTM method. We find excellent full field agreement between measured and computed perforation areas, debris cloud and temperature field

    The Political Economy of Financial Fragility

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    While financial liberalization has in general favorable effects, reforms in countries with poor regulation is often followed by financial crises. We explain this variation as the outcome of lobbying interests capturing the reform process. Even after liberalization, market investors must rely on enforcement of investor protection, which may be structured so as to block funding for new entrants, or limit their access to refinance after a shock. This forces inefficient default and exit by more leveraged entrepreneurs, protecting more established producers. As a result, lobbying may deliberately worsen financial fragility. After large external shocks, borrowers from the political elite in very corrupt countries may successfully lobby for weak enforcement, and retain control of collateral. We provide evidence that industry exit rates and profit margins after banking crises are higher in the most corrupt countries

    Self-Validating Thermocouple

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    Self-Validating Thermocouple (SVT) Systems capable of detecting sensor probe open circuits, short circuits, and unnoticeable faults such as a probe debonding and probe degradation are useful in the measurement of temperatures. SVT Systems provide such capabilities by incorporating a heating or excitation element into the measuring junction of the thermocouple. By heating the measuring junction and observing the decay time for the detected DC voltage signal, it is possible to indicate whether the thermocouple is bonded or debonded. A change in the thermal transfer function of the thermocouple system causes a change in the rise and decay times of the thermocouple output. Incorporation of the excitation element does not interfere with normal thermocouple operation, thus further allowing traditional validation procedures as well

    Physics Based Model for Cryogenic Chilldown and Loading. Part III: Correlations

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    In this report we discuss the details of the correlations used to recognize flow patterns and predict frictional losses, heat and mass transfer in the cryogenic two phase flow. The emphasis are put on the formulation of the correlation problem in terms of concise parametric and functional spaces allowing for efficient online search of the model parameters and accurate prediction of the phenomena observed during cryogenic loading. A special attention is paid to the discussion of the correlation dependence on the gravity. In this context the physics of stability, friction, and boiling in the two-phase flow that underlies the required correlations is discussed

    Climate, geographic distribution and viviparity in Liolaemus (Reptilia; Squamata) species: when hypotheses need to be tested

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    La distribución de los reptiles, dada su dependencia de la temperatura, puede verse restringida en función del clima. En particular, se han planteado tres hipótesis que vinculan el clima con la distribución y el viviparismo en las especies de reptiles: i) hipótesis de clima variable, ii) hipótesis del clima frío e iii) hipótesis de manipulación materna. Entre las lagartijas de Sudamérica las especies del género Liolaemus se distribuyen tanto en ambientes cálidos como fríos y más del 50 % de ellas son vivíparas. En este trabajo estudiamos 47 especies de Liolaemus, tomando datos climáticos de sus sitios de colecta, su temperatura de preferencia (Tpref), el coeficiente de variación de la misma (CV) y los límites de tolerancia térmica (TT). Nuestros resultados no apoyan la hipótesis de clima variable, aunque ésta ha sido sustentada en estudios anteriores. Se encontró relación entre viviparismo y altitud, pero no entre viviparismo y las variables térmicas ambientales. Finalmente, las especies vivíparas de Liolaemus mostraron un comportamiento termorregulador más preciso que las especies ovíparas, reforzando la hipótesis de manipulación materna.Reptile’ distributions, under the light of their strong dependence on particular temperature requirements, may be constrained as a consequence of climate. The relationship between reptile viviparity and climate yielded two previously proposed hypotheses (the cold climate and the maternal manipulation hypotheses) that together with the climatic variability hypothesis; theoretically link climate, distribution and reproductive mode. The extensive variation in mean environmental temperature associated with changes in parity strategies has received much attention in this ectothermic group. Among Southamerican lizards, Liolaemus are distributed in cold and warm regions and more than 50 % of described species are viviparous. We studied 47 Liolaemus species considering climatic data where collected, preferred body temperature, its coefficient of variation and their thermal tolerance. Our results do not support the climate variability hypothesis, previously supported in other studies. We found a relationship between viviparity and elevation, but not between viviparity and thermal climatic variables. Finally, viviparous Liolaemus species showed more precise thermoregulatory behavior than oviparous ones, supporting the maternal manipulation hypothesis.Agencia Nacional de Promoción Científica y Tecnológica de Argentina (PICT 06-01205) y Consejo Nacional de Investigaciones científicas y Tecnológicas (PIP 2846 y PIP 6287)
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