97 research outputs found
Adsorption of butanol and water vapors in silicalite-1 films with a low defect density
Pure silica zeolites are potentially hydrophobic and have therefore been considered to be interesting candidates for separating alcohols, e.g., 1-butanol, from water. Zeolites are traditionally synthesized at high pH, leading to the formation of intracrystalline defects in the form of silanol defects in the framework. These silanol groups introduce polar adsorption sites into the framework, potentially reducing the adsorption selectivity toward alcohols in alcohol/water mixtures. In contrast, zeolites prepared at neutral pH using the fluoride route contain significantly fewer defects. Such crystals should show a much higher butanol/water selectivity than crystals prepared in traditional hydroxide (OHâ) media. Moreover, silanol groups are present at the external surface of the zeolite crystals; therefore, minimizing the external surface of the studied adsorbent is important. In this work, we determine adsorption isotherms of 1-butanol and water in silicalite-1 films prepared in a fluoride (Fâ) medium using in situ attenuated total reflectanceâFourier transform infrared (ATRâFTIR) spectroscopy. This film was composed of well intergrown, plate-shaped b-oriented crystals, resulting in a low external area. Single-component adsorption isotherms of 1-butanol and water were determined in the temperature range of 35â80 °C. The 1-butanol isotherms were typical for an adsorbate showing a high affinity for a microporous material and a large increase in the amount adsorbed at low partial pressures of 1-butanol. The LangmuirâFreundlich model was successfully fitted to the 1-butanol isotherms, and the heat of adsorption was determined. Water showed a very low affinity for the adsorbent, and the amounts adsorbed were very similar to previous reports for large silicalite-1 crystals prepared in a fluoride medium. The sample also adsorbed much less water than did a reference silicalite-1(OHâ) film containing a high density of internal defects.The results show that silicalite-1 films prepared in a Fâ medium with a low density of defects and external area are very promising for the selective recovery of 1-butanol from aqueous solutions
Biased Estimates of Environmental Impact in the Negative Footprint Illusion: The Nature of Individual Variation
People consistently act in ways that harm the environment, even when believing their actions are environmentally friendly. A case in point is a biased judgment termed the negative footprint illusion, which arises when people believe that the addition of âeco-friendlyâ items (e.g., environmentally certified houses) to conventional items (e.g., standard houses), reduces the total carbon footprint of the whole item-set, whereas the carbon footprint is, in fact, increased because eco-friendly items still contribute to the overall carbon footprint. Previous research suggests this illusion is the manifestation of an âaveraging-bias.â We present two studies that explore whether peopleâs susceptibility to the negative footprint illusion is associated with individual differences in: (i) environment-specific reasoning dispositions measured in terms of compensatory green beliefs and environmental concerns; or (ii) general analytic reasoning dispositions measured in terms of actively open-minded thinking, avoidance of impulsivity and reflective reasoning (indexed using the Cognitive Reflection Test; CRT). A negative footprint illusion was demonstrated when participants rated the carbon footprint of conventional buildings combined with eco-friendly buildings (Study 1 and 2) and conventional cars combined with eco-friendly cars (Study 2). However, the illusion was not identified in participantsâ ratings of the carbon footprint of apples (Study 1 and 2). In Studies 1 and 2, environment-specific dispositions were found to be unrelated to the negative footprint illusion. Regarding reflective thinking dispositions, reduced susceptibility to the negative footprint illusion was only associated with actively open-minded thinking measured on a 7-item scale (Study 1) and 17-item scale (Study 2). Our findings provide partial support for the existence of a negative footprint illusion and reveal a role of individual variation in reflective reasoning dispositions in accounting for a limited element of differential susceptibility to this illusion
The negative footprint illusion is exacerbated by the numerosity of environment-friendly additions: unveiling the underpinning mechanisms
The addition of environmentally friendly items to conventional items sometimes leads people to believe that the carbon footprint of the entire set decreases rather than increases. This negative footprint illusion is supposedly underpinned by an averaging bias: people base environmental impact estimates not on the total impact of items but on their average. Here, we found that the illusionâs magnitude increased with the addition of a greater number of âgreenâ items when the number of conventional items remained constant (Studies 1 and 2), supporting the averaging-bias account. We challenged this account by testing what happens when the number of items in the conventional and âgreenâ categories vary while holding the ratio between the two categories constant (Study 3). At odds with the averaging-bias account, the magnitude of the illusion increased as the category size increased, revealing a category-size bias, and raising questions about the interplay between these biases in the illusion
Cross-reactive EBNA1 immunity targets alpha-crystallin B and is associated with multiple sclerosis
Multiple sclerosis (MS) is an inflammatory disease of the central nervous system, for which and Epstein-Barr virus (EBV) infection is a likely prerequisite. Due to the homology between Epstein-Barr nuclear antigen 1 (EBNA1) and alpha-crystallin B (CRYAB), we examined antibody reactivity to EBNA1 and CRYAB peptide libraries in 713 persons with MS (pwMS) and 722 matched controls (Con). Antibody response to CRYAB amino acids 7 to 16 was associated with MS (OR = 2.0), and combination of high EBNA1 responses with CRYAB positivity markedly increased disease risk (OR = 9.0). Blocking experiments revealed antibody cross-reactivity between the homologous EBNA1 and CRYAB epitopes. Evidence for T cell cross-reactivity was obtained in mice between EBNA1 and CRYAB, and increased CRYAB and EBNA1 CD4 T cell responses were detected in natalizumab-treated pwMS. This study provides evidence for antibody cross-reactivity between EBNA1 and CRYAB and points to a similar cross-reactivity in T cells, further demonstrating the role of EBV adaptive immune responses in MS development
Effects of labeling a product eco-friendly and genetically modified: A cross-cultural comparison for estimates of taste, willingness to pay and health consequences
As the demand for eco-friendly food-produced without pesticides and environmentally harmful chemicals-increases, the need to develop genetically modified (GM) organisms that are more resistant to parasites and other environmental crop threats may increase. Because of this, products labeled both "eco-friendly" and "genetically modified" could become commonly available on the market. In this paper, we explore-in a Swedish and a UK sample-the consequences of combining eco-labeling and GM-labeling to judgments of taste, health consequences and willingness to pay for raisins. Participants tasted and evaluated four categories of raisins (eco-labeled and GM-labeled; eco-labeled; GM-labeled; and neither eco-labeled nor GM-labeled). The results suggest that there is a cost associated with adding a GM-label to an eco-labeled product: The GM-label removes the psychological benefits of the eco-label. This negative effect of the GM-label was larger among Swedish participants in comparison with UK participants, because the magnitude of the positive effect of the eco-label was larger in the Swedish sample and, hence, the negative effects of the GM-label became more pronounced (especially for health estimates). The roles of individual differences in attitudes, environmental concern and socially desirable responding in relation to the label effects are discussed
The green halo: Mechanisms and limits of the eco-label effect
Consumers believe that âeco-labeledâ products taste better, which, at least in part, may be an effect of the label. The purpose of the current series of experiments was to examine some mechanisms and limits of this eco-label effect. In Experiment 1, an eco-label effect of similar magnitude was found for taste ratings of both conventional and organic bananas. Experiment 2 showed eco-label effects for a wider range of judgmental dimensions (i.e., health, calories, vitamins/minerals, mental performance, and willingness to pay) and the effect was about the same in magnitude for judgments of grapes and raisins. Experiment 3, with water as the tasted product, found no eco-label effect on judgments of taste, calories and vitamins/minerals, but an effect on willingness to pay, judgments of health benefits and judgments of mental performance benefits. Experiments 2 and 3 also included questionnaires on social desirability traits, schizotypal traits and pro-environmental consumer traits. The last was the strongest predictor of the eco-label effect amongst the three. In all, the eco-label effect is a robust phenomenon, but depends on interactions between product type and judgmental dimension. Implications for several accounts of the effect are discussed
Measurement of the Tau Lepton Polarisation at LEP2
A first measurement of the average polarisation P_tau of tau leptons produced in e+e- annihilation at energies significantly above the Z resonance is presented. The polarisation is determined from the kinematic spectra of tau hadronic decays. The measured value P_tau = -0.164 +/- 0.125 is consistent with the Standard Model prediction for the mean LEP energy of 197 GeV.A first measurement of the average polarisation PÏ of tau leptons produced in e + e â annihilation at energies significantly above the Z resonance is presented. The polarisation is determined from the kinematic spectra of tau hadronic decays. The measured value PÏ=â0.164±0.125 is consistent with the Standard Model prediction for the mean LEP energy of 197 GeV.A first measurement of the average polarisation P_tau of tau leptons produced in e+e- annihilation at energies significantly above the Z resonance is presented. The polarisation is determined from the kinematic spectra of tau hadronic decays. The measured value P_tau = -0.164 +/- 0.125 is consistent with the Standard Model prediction for the mean LEP energy of 197 GeV
Effects on estimation accuracy of forest variables using different pulse density of laser data
Collection of airborne laser scanner data for forest inventory is becoming a common practice today. To reduce cost when laser data are collected over large areas, the flight altitude or flight speed may be increased, resulting in low pulse density laser data. The effect of using a different pulse density of laser data on estimation accuracy of forest variables was investigated at stand level. Laser data were acquired by the airborne TopEye system at a 1,200-ha forest area located in southern Sweden (58°30âČN, 13°40âČE). The 70 selected stands were dominated by Norway spruce [Picea abies (L.) Karst.] and Scots pine (Pinus sylvestris L.) with tree height in the range of 6-28 m (mean 19 m) and stem volume in the range of 30-620 m3 haâ1 (average 286 m3 haâ1). Regression analysis was used to establish empirical functions at stand level. The pulse density of laser data was reduced from 25,000 to 40 returns haâ1. By reducing the pulse density the root mean square error (RMSE) for the tree height and stem volume estimation increased from 0.7 to 1.8 m and from 13% to 29%, respectively. A substantial decrease in estimation accuracy of tree height and stem volume could be observed at pulse densities <80 returns haâ1 (corresponding to about 10 m between adjacent laser returns). The rapid increase in RMSE at these pulse densities could be explained by the less accurate classification of ground returns. With access to a high resolution digital elevation model the RMSE for the tree height and stem volume estimation increased from 0.7 to 1.1 m and from 13% to 23%, respectively, as an effect of the reduced pulse density. Even though the pulse density was reduced to several meters between adjacent laser returns, the estimation accuracies were equal to or better than those commonly obtained by using conventional forest inventory methods, e.g., aerial photo interpretation. This finding implies that low pulse density airborne laser scanner data could be cost efficient to use in inventory for estimation of forest variables at stand level
Change detection of mountain birch using multi-temporal ALS point clouds
The use of multi-temporal laser scanner data is potentially an efficient method for monitoring of vegetation changes, for example, at the alpine treeline. Methods for relative calibration of multi-temporal airborne laser scanning (ALS) data sets and detection of experimental changes of tree cover in the forestâtundra ecotone was tested in northern Sweden (68° 20âČ N, 19° 01âČ E). Trees were either partly or totally removed on 6 m radius sample plots to simulate two classes of biomass change. Histogram matching was successfully used to calibrate the laser metrics from the two data sets and sample plots were then classified into three change classes. The proportion of vegetation returns from the canopy was the most important explanatory variable, which provided an overall accuracy of 88%. The classification accuracy was clearly dependent on the density of the forest
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