Turkish Journal of Engineering and Environmental Sciences 

About: Turkish Journal of Engineering and Environmental Sciences is an academic journal. The journal publishes majorly in the area(s): Freundlich equation & Nusselt number. It has an ISSN identifier of 1300-0160. Over the lifetime, 628 publications have been published receiving 7411 citations.

The Power of Statistical Tests for Trend Detection

Abstract: The existence of a trend in a hydrological time series is detected by statistical tests. The power of a test is the probability that it will reject a null hypothesis when it is false. In this study, the power of the parametric t-test for trend detection is estimated by Monte Carlo simulation for various probability distributions and compared with the power of the non-parametric Mann-Kendall test. The t-test has less power than the non-parametric test when the probability distribution is skewed. However, for moderately skewed distributions the power ratio is close to one. Annual streamflow records in various regions of Turkey are analyzed by the two tests to compare their powers in detecting a trend.

Biological and green synthesis of silver nanoparticles

Abstract: Polycation-sensitive membrane electrodes based on dinonylnaphthalene sulfonate (DNNS) were examined for the determination of some polyanions, namely xanthan (Xanth), alginate (Alg), carboxymethyl cellulose (CMC), and carrageenan (Carr). The potentiometric titrations of polyanionic analytes yielded sharp end points and correlative stoichiometries. After the determinations were successfully performed in saline, these polyanions were also determined in some food products consumed in Bolu (Turkey). In addition, the titration data were used to estimate the interactions between titrant and polyanionic analytes. The equilibrium constants, Keq, and the number of titrant binding sites (n) per mole of analyte polyanion were calculated using Scatchard plots. The accuracy of the assayed method was confirmed by recovery experiments in spiked samples. Dynamic ranges for the determination of polyanionic analytes were 2--20 m g/mL for CMC, 1--8 m g/mL for Xanth, 0.5--4 m g/mL for Alg, and 2--20 m g/mL for Carr. LOD values were

Use of Gamma Distribution in Hydrological Analysis

Abstract: In this study, amounts of daily rainfall and the ascension curve of the hydrograph are investigated. In both cases, the 2-parameter gamma distribution is used. The distribution is fitted to the amounts of daily rainfall and to the differences between the flows of successive days on the ascension curve of the hydrograph. The shape and scale parameters of the distribution, in both cases, are estimated in a monthly time interval. A 30-year daily rainfall series and a 35-year daily runoff series are used for the application. It may be seen that the distribution fits very well to the rainfall data and also that the ascension curve of the hydrograph can easily be represented by the distribution.

Removal of Lead Ion from Industrial Wastewaters by Activated Carbon Prepared from Periwinkle Shells (Typanotonus fuscatus)

Abstract: Lead adsorption from industrial wastewater was studied with the aim of detoxifying industrial effluents before their safe disposal onto land or into river waters. Activated periwinkle shell carbon (PSC) was prepared and characterised for various physiochemical properties. To determine lead(II) removal capacity, the performance of PSC was compared with that of commercial activated carbon (CAC) and a mixture of PSC and CAC (PSC: CAC) in a ratio 1:1. The effect of various parameters such as adsorbent dose, contact time, pH, agitation speed, and particle size of the adsorbent was studied to optimise the conditions for maximum adsorption. Batch adsorption kinetic experiments revealed that the adsorption of Pb(II) onto PSC involved fast and slow processes. The mechanisms of the rate of adsorption were analysed using the Elovich equation and a pseudo-second-order model. It was found that the adsorption mechanisms in the lead/adsorbent system follow pseudo-second-order kinetics with a significant contribution from film diffusion. The adsorption isotherms were described by means of the Langmuir and Freundlich isotherms and both models represent the adsorption process. The percentage removal of lead onto PSC, PSC:CAC, and CAC was 82.78%, 92.68%, and 88.44%, respectively.

Vulnerability of Turkey to Desertification With Respect to Precipitation and Aridity Conditions

Abstract: Climatic factors that may lead to desertification in Turkey were investigated by analysis of the spatial and temporal variations of the precipitation and aridity index series, for the period 1930-1993. Semi-arid and dry sub-humid environmental conditions are dominant over the continental interiors and South-eastern Anatolia. Persistent dry conditions have been evident for the past two decades over a considerable part of Turkey. There has been a general tendency from humid conditions of around the 1960's towards dry sub-humid climatic conditions in the aridity index values of many stations and of Turkey, in general. At some stations in the Aegean Region, there has been a significant change from humid conditions to dry sub-humid or semi-arid climatic conditions. With regard to climatic factors, South-eastern Anatolia and the continental interiors of Turkey appear to be aridlands that are prone to desertification. When other natural and anthropogenic factors, such as high topography, forest fires and unsustainable use of agricultural lands are also taken into account, the Mediterranean and Aegean regions could be more vulnerable to desertification processes in the future.