Searching for a Kuznets curve in environmental efficiency using kernel estimation

Cataloged from PDF version of article.The paper constructs environmental efficiency indexes for a sample consisting of high- and low-income countries using nonparametric production frontier techniques and then establishes an environmental Kuznets relationship for environmental efficiency by Nadaraya-Watson kernel estimation methodology. (C) 2000 Elsevier Science S.A. All rights reserved. JEL classification: Q25; Q32

Catching-up and innovation in high and low income countries

Cataloged from PDF version of article.The study utilizes a variant of the Malmquist Productivity Index computed by nonparametric linear programming techniques to empirically investigate the catching-up hypothesis for a group of high- and low-income countries. The results show that the countries with low initial per capita income levels catch up at a faster rate while countries with relatively high income depend more on technological progress for their productivity increases

The role of international trade on environmental efficiency

Cataloged from PDF version of article.The relationship between trade and environmental conditions receives considerable attention whenever countries are in the process of negotiating trade agreements. In this paper using a non-parametric non-stochastic production frontier approach, we first develop an environmental efficiency index for a sample of high income and low and middle income countries and then examine the role of trade on the changes in environmental efficiency. The paper shows that, in addition to the per capita income which exhibits an environmental Kuznets type relationship, trade-related variables such as trade composition, the share of polluting exports and openness of a country are important determinants of environmental efficiency. (C) 2001 Elsevier Science B.V. All rights reserved. JEL classifications: Q32; Q25; F43

FMR Study of Co/Ti Bilayer Thin Films

. We focused on the interaction between two ferromagnetic cobalt layers through a non-magnetic titanium layer. The magnetic properties of the structure were characterized by ferromagnetic resonance technique (FMR). The data were collected as a function of non-magnetic titanium layer thickness. Co/Ti multilayer (Ti (50 {\AA})/Co(45 {\AA})/Ti(2-40 {\AA})/Co(40 {\AA})/Ti(100 {\AA}))films were grown onto naturally oxidized p-type single crystal Si (100) substrate at UHV condition with magnetron sputtering system at room temperature. The thickness of Ti spacer layer ranges from 2 to 40 {\AA} with 2 {\AA} steps. We did not observe usual optic and acoustic modes; instead we had two broad overlapped peaks for the films ranged from 6 {\AA} to 40 {\AA}. One interesting result was the high anisotropic resonance field values for these films. Exchange coupling between ferromagnetic layers causes shift on resonance field values but these shifts in our samples were much larger than expected. This large anisotropic behavior is not clear at the moment. Our theoretical model was not able to determine a value for the exchange coupling parameter. One reason can be the close thickness values for Co sublayers. The other reason can be the Ti non-magnetic layer. If titanium did not grow layer by layer on cobalt, the cobalt ferromagnetic layers may behave as a single layer. As a result one cannot observe exchange interaction between ferromagnetic layers through non-magnetic spacer.Comment: 6 pages, 5 figure

Topological crystalline insulator states in Pb(1-x)Sn(x)Se

Topological insulators are a novel class of quantum materials in which time-reversal symmetry, relativistic (spin-orbit) effects and an inverted band structure result in electronic metallic states on the surfaces of bulk crystals. These helical states exhibit a Dirac-like energy dispersion across the bulk bandgap, and they are topologically protected. Recent theoretical proposals have suggested the existence of topological crystalline insulators, a novel class of topological insulators in which crystalline symmetry replaces the role of time-reversal symmetry in topological protection [1,2]. In this study, we show that the narrow-gap semiconductor Pb(1-x)Sn(x)Se is a topological crystalline insulator for x=0.23. Temperature-dependent magnetotransport measurements and angle-resolved photoelectron spectroscopy demonstrate that the material undergoes a temperature-driven topological phase transition from a trivial insulator to a topological crystalline insulator. These experimental findings add a new class to the family of topological insulators. We expect these results to be the beginning of both a considerable body of additional research on topological crystalline insulators as well as detailed studies of topological phase transitions.Comment: v2: published revised manuscript (6 pages, 3 figures) and supplementary information (5 pages, 8 figures

Synchronization of multi-phase oscillators: An Axelrod-inspired model

Inspired by Axelrod's model of culture dissemination, we introduce and analyze a model for a population of coupled oscillators where different levels of synchronization can be assimilated to different degrees of cultural organization. The state of each oscillator is represented by a set of phases, and the interaction --which occurs between homologous phases-- is weighted by a decreasing function of the distance between individual states. Both ordered arrays and random networks are considered. We find that the transition between synchronization and incoherent behaviour is mediated by a clustering regime with rich organizational structure, where some of the phases of a given oscillator can be synchronized to a certain cluster, while its other phases are synchronized to different clusters.Comment: 6 pages, 5 figure

Electrode Fixation with Bone Cement or Stimloc (R) in Deep Brain Stimulation Surgery: A Comparative Study

AIM: To examine the postoperative outcomes of electrode fixation using bone cement and Stimloc?? in patients with Parkinson???s MATERIAL and METHODS: Between 2016 and 2018, permanent electrode fixation was performed in 30 patients with PD, of which 15 received bone cement and the remaining 15 received Stimloc??. Data regarding preoperative Unified Parkinson???s Disease Rating Scale (UPDRS) III scores, levodopa equivalent daily dose (LEDD) values, surgery duration, and the fixation technique used were recorded. Brain computed tomography was performed for early postoperative evaluation of pneumocephalus and possible hematoma as well as for the determination of migration 1 year postoperatively. UPDRS III scores and LEDD values were re-evaluated 1 year postoperatively; surgery duration, clinical effectiveness, and complication rates were compared between the two fixation techniques. RESULTS: A statistically significant difference in application time was observed between the two techniques (bone cement: 21 min, Stimloc??: 6 min). After 1 year from surgery, 0.92- and 0.88-mm migrations were observed in the bone cement and Stimloc?? groups, respectively. A significant correlation between migration and the pneumocephalus volume was observed in both groups. No differences were observed between the groups regarding infection, migration, pneumocephalus volume, wound erosion, and CONCLUSION: Stimloc?? is preferred over bone cement for electrode fixation in DBS surgeries as it is associated with shorter application duration; this increases patient comfort and tolerance during awake surgery. Clinical efficacy and complication rates associated with both techniques are similar

Environmental efficiency in carbon dioxide emissions in the OECD: A non-parametric approach

The role of the environment is an important issue in the policy-making and hence, the accurate assessment of the environmental conditions is vital. In this paper, an environmental efficiency index is developed for the OECD countries using non-parametric techniques. The approach adopted is based on the assumption that there is just one production process behind the production of both goods and pollution emissions. The index derived in this work measures the extent of the required output sacrifice, due to the transformation of the production process, from one where all outputs are strongly disposable to the one which is characterized by weak disposability of pollutants. Using this index, we first conduct cross-section comparisons on the state of each country's production process in its treatment of pollution emissions. We then trace each country's modification of their production processes overtime. The results indicate that if the disposability for CO2 emissions were strictly restricted as the result of an environmental regulation, the total value of output loss to the OECD countries as a whole would correspond to 3.7, 4.8 and 3.5% of the total OECD GDP for 1980, 1985 and 1990, respectively. © 2000 Academic Press

Rehydration, pH, brix, titrable acidity and color variations of infrared and microwave dried European Cranberrybush

This work aims at investigating rehydration, pH, brix, titrable acidity and color in infrared and microwave drying of European Cranberrybush. Drying experiments were carried out at infrared temperature of 60, 70 and 80 degrees C and microwave power of 120 and 350 W. The results showed that both the infrared temperature and microwave power influenced the drying time. The slope of the higher infrared temperature or microwave power was found steeper in drying rate. Under the all drying experiments, good rehydration ratio was obtained. The maximum change of the brix and titrable acidity were determined by 350 W. In terms of pH, infrared dried at 60 degrees C samples had higher pH than fresh samples. By comparison colorimetric parameters (L*, a*, b* and C), being highest values were reached at 80 degrees C, whereas the lowest values were achieved at 350 W. In addition, the total color change (Delta E) of European Cranberrybush dried at infrared and microwave methods were found significantly different (P < 0.05)