Charging into the Blend Wall: Conjoint Analysis of Consumer Willingness to Pay for Ethanol Blend Fuels

Ethanol use in the U.S. rose sharply in recent years due to public policy and a spike in petroleum prices, and remains high. Public support for ethanol includes mandated minimum levels of use nationwide. However, rather little is known about consumer demand for ethanol and much less about demand by type of blend and ethanol source. We used trial survey data and conjoint analysis to overcome the lack of historical data on consumers’ preferences for ethanol blend fuels. Preliminary findings based on responses from vehicle drivers in Missouri suggest that price is the primary factor behind fuel preferences. The disclosure of ethanol originated from woody feedstocks had a significant effect on preferences ceteris paribus. Ethanol blends of 20 percent had a negatively non-significant statistical effect compared to no-ethanol fuels or those with a 10 percent content. These findings will be tested using different models expanded to a nationwide pool of motor vehicle drivers.Ethanol blend fuels, consumers’ willingness to pay, choice-based model, Consumer/Household Economics, Environmental Economics and Policy, Production Economics,

VCD helps others in molecular aggregates

Molecular self-assembly is the driving force of a great number of physical, chemical and biological processes in Nature.1 The properties of the molecular aggregates are markedly dependent on the intermolecular forces which hold together the building blocks, but also on the chemical and structural features of these building blocks. The transference of properties from the individual molecules to the bulk aggregate can be summarized in three main behaviours: disappearance (dipole moment), direct sum (weight) and enhancement (resilience). A nice example of the last group is the optical activity. The presence of a chiral seed in the molecules modulates their folding by favouring one among the available macrostructures. As a consequence, new forms of supramolecular chirality are triggered, such as helical, spiral or chiral sheets, which usually give rise to a noticeable increasing of the chiral signal of the aggregates. Vibrational circular dichroism (VCD) is the chiral version of infrared spectroscopy. It combines the intramolecular view provided by the molecular vibrations with the selective capability of a chiral analysis. It is also a suitable technique to observe the aggregation-induced signal enhancement in any type of condensed phase (solid, liquid, gel, etc). Here we present a series of studies on supramolecular systems, Figure 1, in which VCD helps and improves the analysis obtained by other techniques of chiral analysis as electron microscopy (SEM, AFM), electronic circular dichroism (ECD), Raman optical activity (ROA) or circularly polarized luminescence (CPL). These studies are aimed to obtain structural information of the macromolecular scaffolding useful to control the features and applications of the aggregates.Universidad de Málaga, Campus de Excelencia Internacional Andalucía Tec

Mean waiting time in the M/H2/s queue: application to mobile communications Systems

In this paper a procedure to approximately calculate the mean waiting time in the M/H2/s queue is presented. The approximation is heuristic although based in the intuitive symmetry between the deterministic and balanced hyperexponential-2 distributions. The three parameters which fully describe the H2 distribution are considered, so the approximation can also be used for the M/G/s queue when the first three moments are known. If only the first two moments of the holding time distribution are known, the estimation can also be applied accepting a lesser accuracy. The estimation proposed is a closed formula extremely easy to compute and the results are very accurate. This features makes it helpful in the design of mobile telecommunication systems with more than one channel and queueing allowed (like trunking Private Mobile Radio PMR systems), where holding time distributions with coefficients of variation higher than one may appear. As a second stage, the possibility of calls owning a certain level of priority is studied. Two service classes are considered according to a non-preemtive priority scheme (also known as Head Of the Line or HOL). This priority feature is often required in mobile telecommunications systems to improve the access delay of some special calls by degrading the delay suffered by the rest. If the proportion of calls owning priority is kept low, the degradation is shared by many calls and then kept small. In this paper a procedure to estimate the mean waiting time in queue for each priority class is presented. This procedure is also very easy to compute. The environment for which the results of this paper are intended suggests medium or heavy overall load and light priority load (priority proportion is kept low). This is the situation under which the accuracy of the proposed method is checked. Although simulations are necessary in the final phase of the design, the procedure presented here is helpful as a first quick insight into the system performance.Peer ReviewedPostprint (published version

High Resolution Viscosity Measurement by Thermal Noise Detection

An interferometric method is implemented in order to accurately assess the thermal fluctuations of a micro-cantilever sensor in liquid environments. The power spectrum density (PSD) of thermal fluctuations together with Sader's model of the cantilever allow for the indirect measurement of the liquid viscosity with good accuracy. The good quality of the deflection signal and the characteristic low noise of the instrument allow for the detection and corrections of drawbacks due to both the cantilever shape irregularities and the uncertainties on the position of the laser spot at the fluctuating end of the cantilever. Variation of viscosity below 0.03 mPa$\cdot$s was detected with the alternative to achieve measurements with a volume as low as 50 $\mu$L.Comment: Sensors, MDPI, 201

La tragedia Tarfira (1826) del Conde de Cantillana

Estudio leido en la sesión de la Academia el día 7 de Mayo de 1993

La primera mujer propuesta para ingresar en nuestra Academia

Disertación leida en la sesión del 21-VI-1991

CTPATH: Development of an iOS application to compute ecological routes

El cambio climático se debe en gran parte a la emisión de gases de efecto invernadero como el dióxido de carbono, por tanto, es necesario desarrollar nuevas tecnologías que reduzcan la emisión de estos gases a la atmósfera. Actualmente, las aplicaciones para calcular rutas no tienen en cuenta la relación entre el tiempo de viaje y las emisiones, ni el perfil de conducción del usuario y el tipo de coche. El proyecto CTPATH tiene en cuenta estos factores. CTPATH para iOS tiene como objetivo reducir la cantidad de gases de efecto invernadero que emiten los vehículos cuyo combustible es un derivado del petr ´oleo mediante el uso de rutas más ecológicas. Cualquier usuario puede utilizar la aplicaci ´on sin necesidad de registrarse, aunque si lo desea, podrá hacerlo a través de la aplicación web existente. Registrarse en la aplicación ayuda a calcular cuál es la ruta que mejor se adapta a su forma de conducir y por tanto, ofrecer una mejor experiencia al usuario. Cuando el usuario introduce el punto de inicio y el punto de destino se le muestra una lista de tres posibles rutas a tomar, donde la más ecológica aparece en primer lugar, seguido de otras rutas alternativas que son menos ecológicas y posiblemente más rápidas que la primera. Puede darse el caso de que la ruta más rápida y la más ecológica coincidan, es decir, sean la misma. También puede ocurrir que exista una única ruta o que existan sólo dos rutas diferentes para llegar al destino, en ese caso, una misma ruta aparecerá varias veces en la lista. Cuando el usuario seleccione una ruta, podrá ver las cantidades de gases nocivos emitidos para esa ruta, y desplegar una tabla con las indicaciones que debe tomar para llegar a su destino