Design and performance of cryogenic enclosures for long duration testing of large samples

We have designed a large helium dewar as part of an experiment to investigate gravitational radiation. Two such dewars have been constructed. Our use requires a nonmagnetic dewar to cool an aluminium antenna of approximately 5000 kg to below helium temperatures and to keep the antenna in a stable low temperature environment for extended time. This requires a low temperature volume of 1.5 m inner diameter and 3.1 m length and a cooling system capable of efficiently removing the room temperature enthalpy of 8.5 × 10⁸ J. Our solution to this problem is of wider application than simply gravity wave detection so we have discussed the design philosophy in some detail. As constructed, the apparatus uses less than 1 l of helium per hour when cold.     

Multi-modelling as new estimation schema for high-gain observers

The presented paper proposes a novel method of observer design. A new two-layer observer structure is introduced. The first layer consists of multiple high-gain observers. The latter is built to connect the first layer observers into single one. As the new contribution, the new mapping is defined between an unknown state and measurable outputs allowing to explore new estimation schema. Hence, the proposed method enhances the estimation process for linear and nonlinear systems. Furthermore, it is shown that the introduced observation scheme improves the transients. Illustrative examples are calculated to show the properties of the new observation method.     

Is it environmentally advantageous to use vegetable oil directly as biofuel instead of converting it to biodiesel?

The oil price instability and the measures taken to reduce the increase in greenhouse gas emissions are the main factors promoting the development and use of environmentally friendly energies. From an energy efficiency point of view, biofuels constitute a renewable energy source and its use helps to reduce energy dependency on fossil fuels. The most used biofuels for transport worldwide are biodiesel (BD) and bioethanol. However, there are other options such as straight vegetable oil (SVO).SVO can be small-scale produced in local cooperatives through pressing, filtering and conditioning processes which are much simpler than the ones required for BD production. In this study a comparative life cycle assessment (LCA) of two biofuels obtained from Spanish rapeseed, namely small-scale SVO and large-scale BD, is performed. The LCA methodology allows the two biofuels’ production and their rate of consumption in a vehicle (a truck) to be compared. In this manner, it is possible to assess which is environmentally advantageous: to use SVO directly as biofuel or to convert it to BD. Moreover, LCA is used in the study to calculate the energy return on investment index (EROI) and an energy conversion ratio to evaluate which biofuel is more energy efficient.The obtained results show the environmental benefits of using SVO instead of BD by analyzing representative impact categories defined by the CML and EDIP methods. A sensitivity analysis has also been conducted. EROI indexes for SVO and BD production show a clear preference for SVO as compared to BD.     

Implementation of a Model Output Statistics based on meteorological variable screening for short‐term wind power forecast

A combination of physical and statistical treatments to post‐process numerical weather predictions (NWP) outputs is needed for successful short‐term wind power forecasts. One of the most promising and effective approaches for statistical treatment is the Model Output Statistics (MOS) technique. In this study, a MOS based on multiple linear regression is proposed: the model screens the most relevant NWP forecast variables and selects the best predictors to fit a regression equation that minimizes the forecast errors, utilizing wind farm power output measurements as input. The performance of the method is evaluated in two wind farms, located in different topographical areas and with different NWP grid spacing. Because of the high seasonal variability of NWP forecasts, it was considered appropriate to implement monthly stratified MOS. In both wind farms, the first predictors were always wind speeds (at different heights) or friction velocity. When friction velocity is the first predictor, the proposed MOS forecasts resulted to be highly dependent on the friction velocity–wind speed correlation. Negligible improvements were encountered when including more than two predictors in the regression equation. The proposed MOS performed well in both wind farms, and its forecasts compare positively with an actual operative model in use at Risø DTU and other MOS types, showing minimum BIAS and improving NWP power forecast of around 15% in terms of root mean square error. Further improvements could be obtained by the implementation of a more refined MOS stratification, e.g. fitting specific equations in different synoptic situations. Copyright © 2012 John Wiley & Sons, Ltd.     

Synthesis and application of the first radioligand targeting the allosteric binding pocket of chemokine receptor CXCR3

Strategies for the identification of allosteric modulators of chemokine receptors largely rely on various cell‐based functional assays. Radioligand binding assays are typically not available for allosteric binding sites. We synthesized, purified, and applied the first tritium‐labeled allosteric modulator of the human chemokine receptor CXCR3 (RAMX3, [³H]N‐{1‐[3‐(4‐ethoxyphenyl)‐4‐oxo‐3,4‐dihydropyrido[2,3‐d]pyrimidin‐2‐yl]ethyl}‐2‐[4‐fluoro‐3‐(trifluoromethyl)phenyl]‐N‐[(1‐methylpiperidin‐4‐yl)methyl]acetamide). RAMX3 is chemically derived from 8‐azaquinazolinone‐type allosteric modulators and binds to the CXCR3 receptor with a K_d value of 1.08 nM (specific activity: 80.4 Ci mmol^?1). Radioligand displacement assays showed potent negative cooperativity between RAMX3 and chemokine CXCL11, providing a basis for the use of RAMX3 to investigate other potential allosteric modulators. Additionally, the synthesis and characterization of a number of other full and truncated 8‐azaquinazoline analogues were used to validate the binding properties of RAMX3. We demonstrate that RAMX3 can be efficiently used to facilitate the discovery and characterization of small molecules as allosteric modulators of the CXCR3 receptor.     

‘À la Carte’ Peptide Shuttles: Tools to Increase Their Passage across the Blood–Brain Barrier

Noninvasive methods for efficient drug delivery to the brain is an unmet need. Molecular access to the brain is regulated by the blood–brain barrier (BBB) established by the endothelial cells of brain vessels. Passive diffusion is one of the main mechanisms that organic compounds use to travel through these endothelial cells. This passage across the BBB is determined mainly by certain physicochemical properties of the molecule such as lipophilicity, size, and the presence of hydrogen bond donors and acceptors. One emerging strategy to facilitate the passage of organic compounds across the BBB is the use of peptide shuttles. 1 In using this approach the permeability in front the BBB is, clearly, determined by the combined physicochemical properties of both the cargo and the shuttle. Herein we report the synthesis of a series of variations of one of the more efficient peptide shuttles, (N‐MePhe)_n. These include diverse structural features such as various backbone stereochemistries or the presence of non‐natural amino acids, including halogenated residues. In several cases, we assessed the BBB permeability of both the shuttles alone and linked to a few cargos. Our results show how factors such as stereochemistry or halogen content influences the passage across the BBB and, more importantly, opens the way to a strategy of peptide shuttles ‘à la carte′, in which a particular fine‐tuned shuttle is used for each specific cargo.     

Sexually aggressive and nonaggressive men: Sexual arousal and judgments in response to acquaintance rape and consensual analogues.

Self-identified sexually aggressive (SA) and nonaggressive (NA) college men listened to audiotape analogues of consensual sexual intercourse and acquaintance rape. Phallometric and decision-latency methodology was used to examine sexual arousal and decisions to stop sexual advances in each scenario. Both groups showed increases in penile response to the consensual scenario. Consistent with the inhibition model of sexual aggression, the SA group showed greater sexual arousal and failed to inhibit responding when force was introduced in the rape, whereas the NA group exhibited less arousal and greater inhibition to force. The SA group allowed the rape to continue significantly longer than the NA group. These effects were greatly magnified in SA men who endorsed high calloused sexual beliefs, implying that a cognitive set that justifies sexual aggression and lacks victim empathy may disinhibit sexual arousal and potentiate coercive decision making. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Restructuring and generation of electrical energy in the Iberian Peninsula

Portugal and Spain are on the threshold of the creation of an Iberian electricity market. In order to help its development, the power of the electric interconnection between the countries has been increased and market mechanisms designed to resolve congestion, should it arise. A system of joint supply for the Iberian Peninsula will lead to single price for the whole area except at times when the interconnection is saturated, in which case prices will be somewhat higher in the importing zone. In the medium term, the hope is that both systems will have very similar generating equipment and that their variable costs will equalize due to the substitution of the most obsolete equipment with combined cycle power stations, and to the increase of exchange capacity. The coming into effect of this market will bring about improvements in the security and efficiency of supply in both countries. There will also be some obstacles to overcome, such as, for example, the current regulatory frame deficiencies on power generation, the contacts which exist at present in Portugal between the producers and the National Electricity Network, the asymmetry of the distribution channels in each country, the differences in rates and the limited capacity for exchange.