Spatial Spillover Effects of Mega-City Lockdown Due to Covid-19 Outbreak

With the Covid-19 outbreak, academic studies have been started to calculate the economic effects of the outbreak. Since it is not possible to determine when epidemics/pandemics (or large magnitude earthquakes, etc.) occur, their negative economic effects cannot be precisely predicted. Decreasing consumption and supply at the same time, breaking the supply chain, closing businesses and increasing unemployment are rapidly disrupting economic conditions. The measures are mostly related to issues at the macroeconomic level. If a full curfew is imposed throughout the country, economists are working on how it will have an impact on the economy of the whole country. However, the analysis of the effects at the regional level is discussed secondarily. The aim of this study is to simulate the effects of an economic lock-down that might take place in two important mega cities such as Istanbul and Izmir. As a result of this analysis made using spatial econometrics tools; in the event of a lockdown (or earthquake) in mega cities such as İstanbul and/or İzmir, there will be major economic difficulties that will spread wave by wave to the neighboring cities and then eventually to the whole country

The Balkan Countries in the Process of European Integration: Is there a Convergence Process?

Balkan countries have been rapidly changing since 1990's. In spite of some Balkancountries (such as Turkey and Greece) were relatively stable in 1990s, there was warin Serbia, Montenegro, Croatia, Bosnia-Herzegovina, and Macedonia. Some formersocialist countries (Bulgaria, Slovenia and Romania) and Greece became full memberof EU, after the rugged process. The others have been struggling for this aim. In this process, all Balkan countries have some political, economic and social challenges. The aim of this paper is to investigate whether or not economic convergence among Balkan countries in the process of European Integration in the period of 1997-2007. Totest convergence, we use approach of Barro and Sala-i Martin. Our study indicates that there is no convergence among Balkan countries in the process of European Integration in the period of 1997-2007

Electrospinning of Polymer-free Nanofibers from Cyclodextrin Inclusion Complexes

Cataloged from PDF version of article.The electrospinning of polymer-free nanofibers from highly concentrated (160%, w/v) aqueous solutions of hydroxypropyl-β-cyclodextrin (HPβCD) and its inclusion complexes with triclosan (HPβCD/triclosan-IC) was achieved successfully. The dynamic light scattering (DLS) and rheology measurements indicated that the presence of considerable HPβCD aggregates and the high solution viscosity were the key factors in obtaining electrospun HPβCD and HPβCD/triclosan-IC nanofibers without the use of any polymeric carrier. The HPβCD and HPβCD/triclosan-IC solutions containing 20% (w/w) urea yielded no fibers but only beads and splashes because of the depression of the self-aggregation of the HPβCD. The inclusion complexation of triclosan with HPβCD was studied by isothermal titration calorimetry (ITC) and turbidity measurements. The characteristics of the HPβCD and HPβCD/triclosan-IC nanofibers were investigated by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), X-ray diffraction (XRD), and differential scanning calorimetry (DSC). It was found that the electrospinning of HPβCD/triclosan-IC solution having a 1:1 molar ratio was optimal for obtaining nanofibers without any uncomplexed guest molecules

Electrospun porous cellulose acetate fibers from volatile solvent mixture

Cataloged from PDF version of article.Electrospun porous cellulose acetate (CA) fibers were produced from highly volatile binary solvent system; dichloromethane(DCM)/acetone. The morphology and porous structure of CA fibers were highly dependent on DCM/acetone ratio and the concentration of the solutions. Ribbon-like porous CA fibers were obtained from 5% (w/v) to 10% (w/v) polymer solutions depending on the DCM/acetone ratio; 1/1, 2/1, 3/1 and 9/1 (v/v). Using higher DCM/acetone ratio resulted in bead-free fibers from less concentrated polymer solutions due to the high viscosity of the solutions, in addition, more porous CA fibers were obtained owing to the high volatility of DCM

Cyclodextrin nanofibers by electrospinning

We have demonstrated that cyclodextrin (CD) (a non-polymeric system) can be electrospun into nanofibers by itself; methyl-beta-cyclodextrin (MβCD) nanofibers were electrospun and it was observed that the success of the electrospinning of the CD nanofibers strongly depends on (i) type of solvent, (ii) CD solution concentration and (iii) intermolecular interactions between the CD molecules. © 2010 The Royal Society of Chemistry

Electrospun gamma-cyclodextrin (γ-CD) nanofibers for the entrapment of volatile organic compounds

Electrospinning of gamma cyclodextrin (γ-CD) nanofibers from a DMSO-water solvent system was achieved without using a carrier polymeric matrix. The effects of viscosity and rheological properties on the electrospinnability of γ-CD solutions were examined. XRD and HR-TEM studies confirmed that the electrospun γ-CD nanofibers were amorphous without showing any particular crystalline packing. The surface area of the γ-CD nanofibrous web was three times higher than the γ-CD in powder form. As a preliminary study, we have investigated the molecular entrapment capability of γ-CD nanofibers. γ-CD nanofibers were quite successful for entrapping of VOCs (aniline and toluene) by inclusion complexation, whereas γ-CD in powder form did not show any entrapment capability. © 2013 The Royal Society of Chemistry

Electrospinning of nanofibers from non-polymeric systems: polymer-free nanofibers from cyclodextrin derivatives

Cataloged from PDF version of article.High molecular weight polymers and high polymer concentrations are desirable for the electrospinning of nanofibers since polymer chain entanglements and overlapping are important for uniform fiber formation. Hence, the electrospinning of nanofibers from non-polymeric systems such as cyclodextrins (CDs) is quite a challenge since CDs are cyclic oligosaccharides. Nevertheless, in this study, we have successfully achieved the electrospinning of nanofibers from chemically modified CDs without using a carrier polymer matrix. Polymer-free nanofibers were electrospun from three different CD derivatives, hydroxypropyl-β-cyclodextrin (HPβCD), hydroxypropyl-γ-cyclodextrin (HPγCD) and methyl-β-cyclodextrin (MβCD) in three different solvent systems, water, dimethylformamide (DMF) and dimethylacetamide (DMAc). We observed that the electrospinning of these CDs is quite similar to polymeric systems in which the solvent type, the solution concentration and the solution conductivity are some of the key factors for obtaining uniform nanofibers. Dynamic light scattering (DLS) measurements indicated that the presence of considerable CD aggregates and the very high solution viscosity were playing a key role for attaining nanofibers from CD derivatives without the use of any polymeric carrier. The electrospinning of CD solutions containing urea yielded no fibers but only beads or splashes since urea caused a notable destruction of the self-associated CD aggregates in their concentrated solutions. The structural, thermal and mechanical characteristics of the CD nanofibers were also investigated. Although the CD derivatives are amorphous small molecules, interestingly, we observed that these electrospun CD nanofibers/nanowebs have shown some mechanical integrity by which they can be easily handled and folded as a free standing material

Green and one-step synthesis of gold nanoparticles insorporated into electrospun cyclodextrin nanofibers

Cataloged from PDF version of article.The green and one-step synthesis of gold nanoparticles (Au-NP) incorporated into electrospun cyclodextrin-nanofibers (CD-NF) without the use of a carrier polymer matrix was achieved in this study. Chemically modified CD (hydroxypropyl-β-cyclodextrin (HPβCD)) was used as both a reducing and stabilizing agent as well as a fiber matrix for the electrospinning of HPβCD/Au-NP-NF composite mats. Electrospinning of metallic NP incorporating CD-NF would have exclusive properties by combining the very large surface area of nanofibers with specific functionality of the metal NP and CD