Zonguldak Karaelmas University

About: Zonguldak Karaelmas University is a based out in . It is known for research contribution in the topics: Population & Copolymer. The organization has 1939 authors who have published 4296 publications receiving 62466 citations.

Drivers of environmental performance of cement plants

Abstract: Purpose – This paper aims to reveal the impact of five industry forces (IFs) on implementing input‐based competitive strategies (CSs) and to determine relationship of these CSs on cement plants' environmental performances (EPs).Design/methodology/approach – Data were collected from cement manufacturers in Turkey. This study employed structural equation methodology to examine relationships between IFs, CSs, and EP.Findings – Cement plants with the advantage of low buyer bargaining power, low threat of new entrants, and few rivalries exhibit strong energy and raw material strategies. Also, an advantage of low supplier bargaining power and low threat of substitutes causes competitive raw material strategy. Finally, competitive energy and raw material strategies enhance EP, while competitive human resource strategy has no influence on it.Research limitations/implications – The model should be tested on other organizations in supply chain. Future researches can also investigate the difference of findings to ot...

A modeling approach for iron concentration in sand filtration effluent using adaptive neuro-fuzzy model

Abstract: Effluent iron concentration is an important water quality criterion used for the assessment of the performance of rapid sand filters, in addition to other criteria. This study deals with the prediction of effluent iron concentrations by adaptive neuro-fuzzy (ANFIS) model with input parameters including filter hydraulic loading rate, influent iron concentration, bed porosity and operation time. With trying various types of membership functions, two rule base generation methods, namely subtractive clustering and grid partition were used for a first order Sugeno type inference system. Models were evaluated using root mean squared error (RMSE), index of agreement (IA) and R^2 as statistical performance parameters. The fit between experimental results and model outputs showed good agreement for tap water and deionized water; testing RMSE values were 36.33 and 7.66@mg/L, the IA values were 0.996 and 0.971, and R^2 values were 0.99 and 0.89, respectively. It was concluded that neuro-fuzzy modeling may be successfully used to predict effluent iron concentration in sand filtration.

Suspended SiC particle deposition on plastic mold steel surfaces in powder-mixed electrical discharge machining

Abstract: The discharge gap phenomena in powder-mixed electrical discharge machining are examined using SiC powder mixing in water dielectric liquid. Surface modifications on machined work materials are investigated by means of optical, scanning electron microscopy and energy-dispersive spectroscopy. The experimental studies revealed that the surface morphology drastically affected the additives as means of secondary discharges and particle migration from dielectric liquid. Such mechanisms do not occur randomly and indicate a robust dependency with respect to powder suspension concentration, pulse on duration and current. The influence on discharge transitivity with respect to suspended particle concentration is noted with pock shape development due to secondary discharges followed by an intermediate stage signifying a sudden increase in particle migration from the dielectric liquid. The particles decomposed on the surface at specific operational conditions demonstrating the possibility of methodical surface alloyi...

Experimental investigations of surface roughness in orthogonal turning of unidirectional glass-fiber reinforced plastic composites

Abstract: Cutting parameters and the resulting cutting forces have a great effect on the machinability of materials during the turning process. The effects of cutting parameters on machinability have been examined by many researchers and studies on determination of suitable cutting conditions for various materials are still under investigation. In this study, surface roughness of unidirectional glass-fiber reinforced plastic composite was examined on the basis of cutting parameters such as depth of cut, feed rate, tool geometry, and cutting speed. The surface quality was found to relate closely to the feed rate, cutting speed, and cutting tool.