Yazar "Ucurum, Metin" seçeneğine göre listele
Listeleniyor 1 - 9 / 9
Sayfa Başına Sonuç
Sıralama seçenekleri
Öğe Development of a Fuzzy Exponentially Weighted Moving Average Control Chart with an ?-level Cut for Monitoring a Production Process(Springer Heidelberg, 2021) Goztok, Kader Kaplan; Ucurum, Metin; Ozdemir, AkinStatistical quality control is a useful approach that applies to statistical techniques for monitoring a production system. These charts are effective to monitor the process under certain conditions. On the other hand, the fuzzy set theory is an appropriate tool to deal with an uncertain situation. This paper is fourfold. First of all, triangular fuzzy numbers with an alpha-level cut technique are used for each sample. The alpha-level cut technique is sensitive to satisfy the process requirement. Second, a fuzzy exponentially weighted moving average (FEWMA) control chart is proposed with the alpha-level cut technique. The proposed FEWMA detects small shifts under uncertain situations while using a unity technique for samples. Third, the fuzzy target-focused process capability index (FCpm) index is proposed to measure the fuzzy process performance. Then, a case study is presented to monitor a pumice block plant using the FEWMA control chart with the alpha-level cut and measure the process performance with the FCpm index. Comparative studies are also presented. By using the proposed FEWMA control chart with the alpha-level cut, the accuracy and the flexibility of control specification limits are reported for the case study.Öğe Evaluating the grinding process of granitic rocks using the physico-mechanical and mineralogical properties(Chulalongkorn Univ, Metallurgy & Materials Science Research Inst, 2019) Kahraman, Sair; Ucurum, Metin; Yogurtcuoglu, Emine; Fener, MustafaGranitic rocks are sometimes ground for different purposes. Predicting the mean particle size (d(50)) is useful for planning and cost estimation of purposes. In order to investigate the possibility of predicting the d(50) of ground rock from the physico-mechanical rock properties, six different granites were tested in the laboratory. First, the d(50) values were correlated with the corresponding physico-mechanical properties. The simple regression analysis showed that there were no good correlations between the d(50) and the physico-mechanical properties. Then, the multiple regression analysis was carried out and strong prediction equations were developed. It was also shown that the dominant parameter in grinding was the abrasive mineral content of rock. It is concluded that the d50 of granites can be predicted from the derived multiple regression equations especially for preliminary investigations. The developed estimation equations including index test values are especially useful since they are easy to use.Öğe Modeling design parameters with Taguchi experimental method for obtaining operating conditions for Cu(II) removal through adsorption process(Desalination Publ, 2019) Serencam, Huseyin; Ozdemir, Akin; Teke, Cagatay; Ucurum, MetinOne of the environmental concerns deals with the removal process of pollutants in water and wastewater. In this paper, a removal process was used to eliminate pollutants in water and wastewater. The aim of this paper was to obtain an optimum adsorption condition for the highest metal ions adsorbed (MIA) mg/g. For this particular purpose, a Taguchi L-18 design was conducted. In addition, the signal-to-noise ratio was analyzed for optimum adsorption levels. The analysis of variance was also performed to evaluate the effect of each adsorption condition on MIA (mg/g) values. Moreover, an optimization model was also proposed to find the best optimal setting of adsorption levels. Then, the confirmation tests were performed using optimum coded levels of the adsorption parameters for the verification purpose. The results of the experimental study showed a good performance that Cu(II) removal capacity was found to be 43.66 mg/g. To the best of our knowledge, this research is the first to study natural stone as an efficient, inexpensive and cheap adsorbent for the removal process.Öğe A novel approach to finding optimum operating conditions of design factors for the grinding experiment(Taylor & Francis Inc, 2021) Ucurum, Metin; Ozdemir, Akin; Teke, Cagatay; Tekin, IlkerThe efficiency of grinding experiments is an important issue for many industries. In this paper, a central composite design-based methodology was proposed to investigate the four design factors that affect the particle sizes. The four design factors were specified as mill speed (% of N-c ), ball filling ratio (f(c) ), powder filling ratio (j(b) ) and grinding time (min). Another important issue was how to obtain an optimum operating condition for four design factors. For this particular purpose, a novel dual response optimization model was proposed using the particle sizes (d (10), d (50), and d (90)) and the span value concept. This proposed approach was compared to the desirability function-based optimization concept. The verification study of the experiment was also carried out. The results of the grinding experiment runs showed that the optimum operating conditions were mill speed 73.495% of N-c , ball filling ratio 0.354, powder filling ratio 0.157, and grinding time 70 min. In addition, d (10), d (50), and d (90) were found 3.31 mu m, 12 mu m, and 45.6 mu m, respectively. The span value was also found at 3.52.Öğe A Novel Fuzzy Cumulative Sum Control Chart with an ?-Level Cut Based on Trapezoidal Fuzzy Numbers for a Real Case Application(Springer Heidelberg, 2024) Ozdemir, Akin; Ucurum, Metin; Serencam, HueseyinStatistical process control (SPC) is widely used to monitor production processes in many industries under certain conditions. When dealing with a quality characteristic for uncertainty, fuzzy numbers are used in the context of the statistical process control (SPC) to monitor a fuzzy production process. The aim of this paper is fourfold. One, a fuzzy X-R control chart with an alpha-level cut is used based on trapezoidal fuzzy numbers (TFNs) for detecting the large shifts in the fuzzy process mean. Second, a fuzzy cumulative sum (FCUSUM) control with an alpha-level cut based on TFNs is firstly developed for detecting the small shifts in the fuzzy process mean. Third, the fuzzy process capability indices (FPCIs) are presented to measure the fuzzy process performance. Finally, an ultra-fine calcite production process is controlled with both the fuzzy X-R control chart and the proposed FCUSUM control chart. The results of the fuzzy X-R control charts show that the fuzzy production process is in control, and large shifts in the fuzzy process mean were detected. On the other hand, the results of the FCUSUM charts show that the fuzzy production process is out of control, and small shifts in the fuzzy process mean were detected. FPCIs are also conducted, and the results of fuzzy C-pk indices show that the ultra-fine calcite production process is not capable of meeting specification limits.Öğe A novel weighted mean-squared error optimization model to obtain optimal conditions of adsorption factors for a lead removal process(Desalination Publ, 2021) Ozdemir, Akin; Teke, Cagatay; Serencam, Huseyin; Ucurum, Metin; Gundogdu, AliLead (Pb) removal process from wastewater is an important issue to prevent health problems for people. For this particular purpose, a low-cost adsorbent may be beneficial for improving the adsorption capacity for the Pb removal process. The aims of this paper are four-fold. First of all, a D-optimal experimental design was selected to reduce experimental runs and its cost. Second, the effect of four adsorption design factors, stirring speed (rpm), adsorbent dosage (g), pH level, and initial metal concentration (ppm), was examined. Also, the yellow natural stone, which is from Bayburt, Turkey, was used as a cheap adsorbent for the Pb removal process from the solution. Third, a novel weighted mean-squared error optimization model was developed to obtain optimal adsorption levels for adsorption factors. Besides, a verification study was conducted to verify the results of the adsorption experiment. Finally, the lead (Pb( II)) removal capacity of the yellow Bayburt stone was obtained to be 46.031 mg/g, and the results of the experiment from the proposed methodology showed a good performance for the removal study.Öğe Optimization of mechanochemical surface modification parameters on planetary mill using an I-optimal experimental design(Elsevier, 2024) Ozdemir, Akin; Ucurum, MetinSeveral micro -particle -size additives and filler minerals are added to many industrial products, especially plastic, in order to reduce cost and improve mechanical properties and appearance. Also, grinding and surface modification are two fundamental properties of the filler minerals used in plastic products. Notably, Bayburt stone (BS) used as a natural raw material from Bayburt, Turkiye contains 76% SiO2 and 15% Al2O3. In this paper, the hydrophilic surface structure of micronized Bayburt stone (MBS) was made hydrophobe by mechanochemical surface modification using calcium stearate [Ca(C17H35COO)2] in a laboratory -type planetary mill. Next, the optimum conditions of the surface modification design factors, which are (1) ball filling ratio = 30.53%, (2) powder filling ratio = 10.43%, (3) mill speed = 475.91 rpm, (4) chemical dosage = 1.99% of powder, and (5) modification time = 4.83 min., were obtained using the proposed I -optimal design -focused optimization model when predicting the model parameters. In addition, a coated micronized Bayburt stone (CMBS) product with an active ratio (AR) of 99.90% and d10, d50, and d90 values of 1.32 mu m, 3.48 mu m and 9.55 mu m were achieved. Finally, particle size distribution (PSD), thermo-gravimetric and differential thermal analyzer (TG -DTA), Fourier transform infrared (FTIR), scanning electron microscope (SEM), electron dispersive spectrum (EDS), and contact angle analyses were performed on the CMBS product.Öğe Recovery of unburned carbonaceous matter (UCM) from sugar mill bottom ash(Taylor & Francis Inc, 2020) Katircioglu-Bayel, Diler; Serencam, Huseyin; Ucurum, MetinMillions of tons of coal fly and bottom ash are produced each year in many countries including Turkey. Coal combustion which is the main source of energy in sugar mill and many other industries produce massive quantities of waste. The present study aims to separate the unburned carbonaceous matter (UCM) from the bottom ash of Bor, Nigde-Turkey sugar plant has been studied using the mechanical flotation technique. For this purpose, the performances of three classical oils were investigated and then chemical parameters such as sodium silicate (Na2SiO3), collector (fuel-oil) and frother (pine-oil) were systematically examined by using Yates' statistical technique. A product with 41.58% combustible grade at 87.44% recovery was obtained at 0 g/t sodium silicate, 7464 g/t fuel-oil, 888 g/t pine-oil, 15% pulp density, 1200 rpm impeller speed and natural pH. The results obtained from the experiments indicated that it was possible to enrich the bottom ash by using conventional flotation.Öğe Wet mechanochemical surface modification of calcite employing an integration of conventional design and analytical hierarchy process(Elsevier, 2024) Ucurum, Metin; Ozdemir, AkinThe demand for ultra-fine mineral powders from various industries requires the applications of wet grinding and surface modification. In this study, wet mechanochemical surface modification of micronized calcite (d50 = 4.92 pm) with stearic acid [CH3(CH2)16COOH] was carried out in a planetary ball mill. The seven parameters were specified: ball filling ratio (%), ball size distribution ratio (10 and 15 mm, %), micronized calcite filling ratio (%), pulp solid ratio (wt%), mill speed (rpm), stearic acid dosage (% of micronized calcite) and modification time (min). Then, these parameters were optimized using a conventional experimental design when maximizing the active ratio (%) as a significant value for coated calcite. Besides, the analytical hierarchy process was applied to observe the importance of each parameter. Stearic acid dosage, mill speed, and micronized calcite filling ratio are the top three parameters affecting the active ratio. Next, size distribution, XRF, XRD, SEM, FTIR, TGA-DTA, contact angle, and whiteness measurements were performed on the micronized calcite (MC) and coated micronized calcite (CMC) samples. The final CMC product had a 99.90% active ratio, 2.49 pm mean (d50) particle size, and 101.66o contact angle. Finally, CMC obtained by the surface modification can be used as a filler mineral.
