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161.
162.
Mid-infrared spectroscopy, in association with multivariate chemometric techniques, was employed for pattern recognition and the determination of the composition of waste frying oils (WFO); data are presented in terms of the percentage of soybean oil, palm oil and hydrogenated vegetable fat in frying oil blends. Principal component analysis (PCA) was performed using spectral data (3,000–600 cm−1) to discriminate between the samples containing 100% soybean oil, 100% palm oil, 100% hydrogenated vegetable fat groups and their blends. Additionally, the results indicated that partial least squares (PLS) models based on mid-infrared spectra were suitable as practical analytical methods for predicting the oil contents in WFO blends. PLS models were validated by a representative prediction set, and the root mean square errors of prediction (RMSEP) were 2.8, 4.7 and 5.5% for palm oil, soybean oil and hydrogenated vegetable fat, respectively. The proposed methodology can be very useful for the rapid and low cost determination of waste frying oil composition while also aiding in decisions regarding the management of oil pretreatment and production routes for biodiesel production.  相似文献   
163.
Composites of poly(lactic acid) (PLA) and organoclays with clay loadings of up to 80% were prepared as self‐supporting films using a doctor‐blading approach. Depending on the properties of the used organoclay, either intercalated nanocomposites or conventional composites were obtained. The incorporation of such high amounts of clay resulted in up to 10‐fold decrease in the water vapor transmission rate when compared to the pristine polymer. The effect of clay platelets on the crystallization of PLA chains was also studied; it was found that high amounts of clay hinder only the melt crystallization of the polymer, whereas cold crystallization proceeds as usual. On the other hand, the crystallization of PLA also influenced the composite structure by increasing the extent of intercalation of polymer between clay layers. This study thus shows that the change in the extent of clay‐polymer interactions is also an important factor in controlling nanocomposite structure, especially for high loading. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013  相似文献   
164.
The Wireless Access in Vehicular Environments (WAVE) protocol stack has been recently defined to enable vehicular communication on the Dedicated Short Range Communication (DSRC) frequencies. Some recent studies have demonstrated that the WAVE technology might not provide sufficient spectrum for reliable exchange of safety information over congested urban scenarios. In this paper, we address this issue, and present a novel cognitive network architecture in order to dynamically extend the Control Channel (CCH) used by vehicles to transmit safety-related information. To this aim, we propose a cooperative spectrum sensing scheme, through which vehicles can detect available spectrum resources on the 5.8 GHz ISM band along their path, and forward the data to a fixed infrastructure known as Road Side Units (RSUs). We design a novel Fuzzy-Logic based spectrum allocation algorithm, through which the RSUs infer the actual CCH contention conditions, and dynamically extend the CCH bandwidth in network congestion scenarios, by using the vacant frequencies detected by the sensing module. The simulation results reveal the effectiveness of our architecture in providing dynamic and scalable allocation of spectrum resources, and in increasing the performance of safety-related applications.  相似文献   
165.
Peroxidase activity accounts for quality losses in many plant‐based foods. The paper provides insight into the inactivation kinetics of peroxidase (POD) in carrot juice treated with pulsed electric fields (PEF). Juice samples were subjected to electric field intensities of 20 to 35 kV/cm for 300 to 2000 μs. Up to 93% of the initial activity was inactivated after treating at 35 kV/cm for 1500 μs. POD activity inactivation correlated well with the increase in energy density input. A first‐order fractional conversion model best fitted the experimental results. Other kinetic approaches such as the Fermi's model can be used to estimate residual POD activity values in treated juices as a function of electric field strength. Practical Application : Pulsed electric fields (PEF) are a processing technology that can be used for the pasteurization of liquid food products. Peroxidase activity inhibition is required in carrot juices to prevent undesirable quality losses, such as discoloration, flavor changes, and loss of nutrients. The most significant processing parameters ruling POD inactivation in PEF‐treated carrot juice are identified and mathematical modeling of experimental data is conducted.  相似文献   
166.
This controlled preliminary trial determined the feasibility and initial effectiveness of a promising behavioral intervention for smoking: Acceptance and Commitment Therapy (ACT). In a quasi-experimental design, the ACT intervention condition used metaphors and experiential exercises focused on personal values to motivate quitting smoking and enhancing the willingness to experience internal cues to smoke (e.g., urges) and abstinence-related internal distress. The comparison condition was cognitive behavioral therapy (CBT)—the current standard in behavioral intervention for smoking cessation. Each treatment was delivered in seven weekly 90-min sessions in a group format to 81 (43 in ACT; 38 in CBT) adult smokers. Results show that the ACT treatment was as feasible as the CBT treatment. They also demonstrate promising evidence of ACT’s effectiveness: 30.2% intent-to-treat biochemically-supported 30-day point prevalence at twelve month follow-up, compared with 13.2% in the CBT condition (odds ratio = 5.13; p = .02). Replication in a well-powered, randomized, controlled trial is now needed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
167.
This paper summarises the main results of a European project BEQUAR (Benchmarking Exercise in Quantitative Area Risk Assessment in Central and Eastern European Countries). This project is among the first attempts to explore how independent evaluations of the same risk study associated with a certain chemical establishment could differ from each other and the consequent effects on the resulting area risk estimate. The exercise specifically aimed at exploring the manner and degree to which independent experts may disagree on the interpretation of quantitative risk assessments for the same entity. The project first compared the results of a number of independent expert evaluations of a quantitative risk assessment study for the same reference chemical establishment. This effort was then followed by a study of the impact of the different interpretations on the estimate of the overall risk on the area concerned. In order to improve the inter-comparability of the results, this exercise was conducted using a single tool for area risk assessment based on the ARIPAR methodology. The results of this study are expected to contribute to an improved understanding of the inspection criteria and practices used by the different national authorities responsible for the implementation of the Seveso II Directive in their countries. The activity was funded under the Enlargement and Integration Action of the Joint Research Centre (JRC), that aims at providing scientific and technological support for promoting integration of the New Member States and assisting the Candidate Countries on their way towards accession to the European Union.  相似文献   
168.
This paper presents the results of an investigation through the design of experiment technique regarding the influence of temperature, dwell time and bar pressure on the heat seal strength of oriented polypropylene films coated with a gelatin‐based thin layer. This chemometric approach allowed achieving a thorough understanding of the effect of each independent factor on the two different responses (maximum force and strain energy) considered in this work as a measure of the strength necessary to break the bond across the sealed interface. Surprisingly, the factor affecting both responses the most was the bar pressure rather than the sealing temperature. Moreover, whereas the bar pressure negatively affected the seal strength of coated polypropylene films, the sealing temperature had a positive effect. Dwell time did not have any significant influence as a main factor, while influencing negatively the seal strength as an interaction term (i.e. time × pressure), together with the further interaction temperature × pressure. The mathematical models obtained for the two responses provided different results in terms of fitting capability (R2) and prediction ability (Q2). In particular, for the maximum force response, R2 and Q2 were equal to 0.571 and 0.405, respectively, whereas the model supporting the strain energy response gave R2 = 0.932 and Q2 = 0.937, highlighting that for quantifying the seal strength, the energy necessary to break a seal is a better measure than the maximum force. The highest seal strength values obtained during this work were of 0.6615 N and 19.6 N·mm for maximum force and strain energy, respectively. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   
169.
Most automotive companies outsource the design, manufacturing and assembly of some complete cars to independent suppliers or full service vehicle companies (FSVs). FSVs represent a relatively unexplored form of outsourcing which combines joint efforts in developing a modular product with the externalisation of specific niche manufacturing processes. On the basis of comparative cases and of qualitative information collected within three FSVs and three OEMs, this study aims to investigate the associated advantages and risks for FSVs, commonalities/differences from the practices of outsourcing to component/module specialists that can be found in other industries and why and for what kind of products FSVs can be appropriate in automotive supply networks. The study contributes to the debate on outsourcing in the automotive industry by providing an original interpretation on why FSVs have recently seen a shakeout with some growing whilst others have faltered.  相似文献   
170.
In the vegetable oil chemical industry, hydrogenation is one of the most important processes. An alternative method for vegetable oil hydrogenation is the use of catalytic transfer hydrogenation (CTH), which can utilize organic molecules as hydrogen donors at ambient pressure. These alternative processes should be optimized in relation to the variables required for a good conversion and impacts should also be known to be minimized. An assessment of the environmental impact of laboratory scale chemical processes is an important tool to improve the technological aspects of a process (increased yields, reduced production times, lower costs) and it can also lead to the creation of a cleaner technology. Using the Leopold Matrix, we have succeeded in developing a more efficient and cleaner process for the CTH of castor oil using Raney Ni as a catalyst and cyclohexene or isopropanol as a hydrogen donor solvent. The results of the technical and environmental assessments showed that the extent of conversion for the unsaturation reaction was high (>99 %), and the environmental impact of the process could be significantly reduced to create a cleaner technology. It was found, after process optimization, that the remaining environmental impacts were negative (67.48 %), local (78.95 %), temporary (95.33 %), direct (80.12 %), and reversible (95.32 %).  相似文献   
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