Modeling and forecasting car ownership based on socio-economic and demographic indicators in Turkey

Since car ownership is an important determinant to analyze car travel behavior especially in developing countries, this paper deals with modeling and forecasting car ownership in Turkey based on socio-economic and demographic indicators such as Gross Domestic Product(GDP) per capita, Gasoline Price (GP), car price and number of employees by using multiple nonlinear regression analysis. Although most of the studies on this subject prefer using annual data, we use monthly data for the analysis of car ownership since all explanatory variables and exchange rates used for the modeling are unstable and vary even in a short period in developing countries such as Turkey. Thus, it may be possible to reflect the effects of socio-economic and demographic indicators on car ownership more properly. During the modeling process, exponential and polynomial nonlinear regression models are set up and then tested to investigate their applicability for car ownership forecasting. Based on results of the Kolmogorov-Smirnov test, the polynomial models has been selected to forecast car ownership for the year 2035. In order to reveal the possible different trends of the independent variables in future, car ownership is forecasted along the scenarios which are related to the GDP per capita and GP. Results show that Turkey’s car ownership may vary between 230 and 325 per thousand capita in 2035 depending on economic achievements, global oil prices and national taxation policies. The lowest and the highest values of the car ownership may provide insight to car producers and transport planners in Turkey. Another significant result presented in this study is that car ownership rate will be substantially lower in Turkey than that in the European Union countries despite it has an increasing trend in the past two decades

Work environments for employee creativity

Innovative organisations need creative employees who generate new ideas for product or process innovation. This paper presents a conceptual framework for the effect of personal, social-organisational and physical factors on employee creativity. Based on this framework an instrument to analyse the extent to which the work environment enhances creativity is developed. We apply this instrument to a sample of 409 employees and find support for the hypothesis that a creative work environment enhances creative performance. We illustrate how the instrument can be used in companies to select and implement improvements

Bottom trawl fishery discards in the Black Sea coast of Turkey

The purpose of this study is to determine the amount of bycatch and discardfish caught by bottom trawlers used in the Black Sea coasts of Turkey anddiscard changes depending on the depth. The study was conducted during theSeptember 2009 – April 2010 fishing season. Twenty-one bottom trawleroperations were sampled and the catch composition was determined. A total of 26species were caught, which included 22 species of fish, 2 species of arthropods,1 species of gastropods and 1 species of bivalves. Two of these were targetspecies (Mullusbarbatus, Merlangius merlangus), while 25 species werediscarded including trash fish and specimens below the legal size. A total of2142.76 kg of biomass was caught during the operations, of which 53.99 % bycatch.The weighted discard rate was determined as 42.06% and two different groupswere identified in discards (T1: 10-57 m, T2: 72-118 m) based on the depth. Significantdifferences were identified between these depth groups (p0.05) between theecological parameters of landings

The influence of post-fixation on visualising vimentin in the retina using immunofluorescence method

Background: Post-fixation of sections is especially required for cryostat sections of fresh frozen tissues. Vimentin is an intermediate filament in both fibrillary and non-fibrillary form, expressed in Müller’s cells and astrocytes of the retina. Our aim was to determine the best post-fixation method for visualising vimentin in archival mouse eyes. Materials and methods: We used an archival mouse eye, slightly pre-fixed with paraformaldehyde and stored at –80°C for 4 years. We tried three fixatives (pa­raformaldehyde [PFA], alcohol/acetic acid [AAA] and methanol) for post-fixation of eye sections. Results: We showed that post-fixation alters the labelling properties of vimentin expressed in the retina. In the sections with no post-fixation, vimentin positivity was observed in and around the nuclei in non-fibrillary form. In PFA post-fixed sections, the vimentin in the retina was not observed as fibrils. Positivity was observed in the nuclei and in perinuclear regions of the cells. In AAA post-fixed sections, positive labelling was observed around the nuclei as fibrils. In methanol post-fixed sections, labelling was observed around the nuclei as fibrils. Conclusions: We conclude that post-fixation with AAA is more convenient for immunofluorescent labelling of vimentin in the retina for slightly PFA pre-fixed and long-term stored retina. (Folia Morphol 2018; 77, 2: 246–252

Effect of water-to-binder ratio, air content, and type of cementitious materials on fresh and hardened properties of binary and ternary blended concrete

The purpose of this study is to investigate the effects of water-to-binder ratio (w/b), air content, and type of cementitious material on the fresh and hardened properties of binary and ternary blended concrete mixtures in pavements. This experimental program prepared a total matrix of 54 mixtures with w/b of 0.40 and 0.45; nominal air content of 2, 4, and 8%; and three types of supplementary cementitious materials and one ordinary portland cement in different combinations. Binder systems included ordinary portland cement, binary mixtures with slag cement, Classes F and C fly ash, and ternary mixtures containing a combination of slag cement and one type of fly ash.Workability, total air content, air void system parameters (i.e., spacing factor and specific surface) in fresh concrete, setting time, compressive strength, surface resistivity, and shrinkage were determined. Test results showed that ternary mixtures followed the trends of their constituent materials. Binary and ternary mixtures containing Class C fly ash and slag cement exhibited higher compressive strength than the control mixture. The surface resistivity and shrinkage results of binary and ternary mixtures were equal to or improved over the control mixture

Effect of paste-to-voids volume ratio on the performance of concrete mixtures

The purpose of this study is to investigate the minimum paste volume required with an appropriate water-to-cementitious ratio (w/cm) to achieve required workability, strength, and durability requirements of concrete mixtures for pavements. In this experimental program, 64 concrete mixtures with varying w/cm, cementitious content, and binder type were prepared and tested. The fine aggregateto-total aggregate ratio was held constant for all the mixtures. Fresh and hardened concrete properties of the mixtures were determined at various ages. Test results have shown that approximately 1.5 times more paste by volume is required than voids between the aggregates to achieve a minimum performance in concrete for pavements. For a given w/cm, strength is independent of cementitious content after a critical value is provided. When w/cm is constant, increasing paste content increased chloride penetrability and air permeability