Improved piezoelectric properties of PLA/PZT hybrid composite films

Piezoelectric polymer-ceramic composites are promising materials for Sensing, Wireless electronics and actuating applications. We report the fabrication of highly piezoelectric biocompatible films containing lead zirconate titanate (PZT) ferroelectric ceramic particles dispersed in poly lactic acid (PLA) with different volume fractions using a solvent cast technique. The properties of the piezoelectric polymer-ceramic films were investigated by Fourier transform infrared spectrometry (FTIR) and field emission scanning electron microscopy (FE-SEM). In the FTIR spectra appear a large number of absorption bands which are attributed to the phases from PLA matrix confirming the total embedding of PZT filler into the matrix. The SEM results showed a good distribution of fillers in the matrix. We find that the added PZT imposes a significant effect on the α–β phase transformation. Our finding can lead to extraordinary enhancement of piezoelectric properties for the PLA/PZT composite films

Testing Separability for Common Wheat Qualities in French Import Demand Market Using Aids and Rotterdam Demand Models

This study has used a corrected likelihood ratio, with AIDS and Rotterdam demand models, to test separability in three separable (A, B, C) wheat import demand structures on the French common wheat market. It appears from the study that the three separable Rotterdam structures are accepted by the test, while only two of them (B and C) are accepted in the case of AIDS at 5% level of significance. Meanwhile, model B seems to be more indicated in demand analysis with AIDS since it is the only one accepted at 15% level of significance. The results obtained demonstrate not only the necessity to test separability in demand structures, but also the necessity to know how the allocation models can be used for demand analysis purpose. The study has also shown a great difference in econometric results for AIDS and Rotterdam and pose once more the issue of the choice of a functional form in demand analysis

Review of agricultural trade models: an assessment of models con EU policy relevance

This paper provides an assessment of the present state of applied modelling in the area of international trade in agriculture and related resource and environmental modelling. This review has a deliberate bias on current European policy issues. The outcomes of negotiation rounds such as World Trade Organization trade negotiations and the Kyoto environmental summit, and the prospect of EU enlargement bear implications for European farmers, related supplying and processing industries and European consumers. The assessment of likely policy impact is bound to be complex and should be supported by quantitative modelling analyses that explain the trade relations of European countries with third countries. We provide in this paper a comparative assessment of alternative modelling approaches. This includes theoretical modelling foundations, datasets employed and institutional aspects, such as model maintenance and dissemination of results. A typology of models is provided by structuring the assessment along a clear set of evaluation criteria

Does an Income Gap between Farm and Nonfarm Households Still Exist? The Case of the European Union

The paper compares the income conditions of farm and nonfarm households in the whole EU and within three geographical groups of countries for the period 2008–2016. Overcoming the simple comparison of raw means of the groups, we estimate the farm/nonfarm income differentials by using Regression Adjusted and Covariate Matching techniques, which allow to control for observable characteristics among groups. Three innovative features of our analysis are that we account for the whole income of farm households (i.e. not only farm income), for the presence of inkind incomes from self-consumption of produced goods and imputed rents from properties, and for the complex survey design. We find that an income differential still exists but with relevant differences across countries and along the period. Most of it is due to differences in the households’ characteristics. Hence, comparing raw means of the two groups can be misleading. Nonmonetary sources of income play a not negligible role, improving the relative position of farm households. The role of agricultural and rural policy is discussed in the light of results.3n