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- MakaleAçık Erişim2018Scopus SJRQ1Silica gemstones formation in Yamadag volcanites (Arguvan-Malatya) mineralogical, geochemical, gemological properties and economic importance
Akbudak, Ilkay Kaydu; Basibüyük, Zeynel; Gürbüz, Meltem; Önal, Ayten Oztufekci; Isler, Fikret
Yamadag Volcanics which is one of the examples of the Late Miocene volcanism in Eastern Anatolia covers large areas within the boundaries of Arguvan county of Malatya. The gemstones, subject of this research range from a few centimeters to about 30-40 cm in size and are formed in the cavities of the basalts beonging to Yamadag volcanics. These gemstones seem to have formed as veins extending in east-west direction and consist of opal (opal-CT) and chrysocolla. Opal formations have various colours such as white, brown, yellow and greenish, while chrysocolla formations are bluish-greenish in color. both opal and chrysocolla are of massive type and their fresh surfaces display waxy luster. Mineral paragenesis and formation conditions of gemstones and are determined by applying XRD, SEM, FT-IR techniques. ICP-MS technique is used for the determination of the geochemical compositions. The gemological characteristics are identified via cabochon and facet cut techniques by using diamond coating blade, sintered diamond abrasive discs and polishing machine. Opals are usually composed of tridymite minerals, also in some cases quartz and cristobalite minerals accompany the tridymite minerals. The EDX measurements reveal, enrichment of Fe and Al in opals, and of Cu in chrysocolla. The ICP-MS measurements, in chrysocollas reveal, enrichments in LIL elements such as Ba, Sr and in HFS elements such as U. Consequently, gemological studies show that the chrysocolla and opals in study area, which have waxy luster and massive structure, are suitable for utilization as a gemstone due to its color, hardness, durability, homogeneous distribution of color and processability.
AtıfOpenAlex12
İncele - MakaleAçık Erişim2016Scopus SJRQ2Automatic mining of accurate and comprehensible numerical classification rules with cat swarm optimization algorithm
Akyol, Sinem; Alatas, Bilal
Optimization is the process of finding the best solution of a problem. There are many optimization algorithms proposed for optimization problems. The metaheuristic algorithm can give solutions close to optimum in an acceptable period of time for large-scaled optimization problems. The metaheuristic optimization algorithms are evaluated in seven different groups which are biology-based, physics-based, swarm-based, social-based, music-based, sport-based, and chemistry-based. The swarm-based optimization algorithms have been developed by observing the behaviors of creatures e.g. birds, fishes, cats, bees etc. Data mining is the process of discovery of meaningful and useful data within huge databases. Classification rules mining is one of the most commonly studied data mining problems and with methods for this problem, users can easily understand the rules extracted from databases. In this work, one of the most recent swarm based optimization algorithm, Cat Swarm Optimization (CSO), has been firstly used for classification rules mining within databases composed of numerical or mixed data types automatically. There is not any preprocess for finding true ranges for appropriate attributes of the rules, this has been automatically done by CSO. Furthermore, the used objective function is very flexible and many different objectives can easily be added to. For this purpose, four numerical databases obtained from UCI data warehouse have been used and accurate and comprehensible classification rules have been mined. The results have been compared with the results obtained from Weka program. Although CSO has not been embedded with any improvement and has firstly implemented in this research area, the obtained results seem promising.
AtıfWoS9OpenAlex4İncele - MakaleYalnız künye2013Scopus SJRQ2MULTI OBJECTIVE GENERALIZED RESOURCE CONSTRAINED TWO SIDED ASSEMBLY LINE BALANCING PROBLEM AND COMPUTATIONAL ANALAYSIS
Mete, Suleyman; Agpak, Kursad
Assembly of large size products like bus, truck and automobile can perform both sides of assembly line. In such cases, both sides (right and left) of the line are used to achieve for the assembly operation. These types of the lines are called as two sided assembly lines. When large size products are produced, sometimes they require a specific machine or a qualified staff to use this machine. This condition also exposes the problem of resource constraint. Therefore, in this study, a mathematical model for generalized resource constraint two sided assembly line balancing problem is presented, based on literature models and computational analysis is performed for multi-objective situation. Proposed model is run and analyzed over several known test problems by considering three objective functions (Minimization number of station, number of position and resource cost).
AtıfWoS8İncele - MakaleYalnız künye2010Scopus SJRQ2INFLUENCE OF CURING CONDITIONS AND AGGREGATE TYPE ON MECHANICAL PROPERTIES OF SELF COMPACTING LIGHTWEIGHT CONCRETE
Gönen, Tahir; Yazicioglu, Salih
Lightweight concrete has important advantages, especially in terms of earthquakes. Besides, the production of lightweight concrete with lightweight aggregate is a problem, because workability of lightweight concrete is difficult. If self compaction property can be added to the lightweight concrete, this negativity can be removed. In this study, mechanical properties of self compacting lightweight concrete (SCLWC) containing expanded perlite and pumice aggregates were investigated. Moreover, mechanical properties of self compacting (SCC) and lightweight (LC) concrete were investigated by being compared with SCLWC. Powder phase of self compacting lightweight concrete was consisted of CEM I 42.5 N cement type and C class fly ash. Pumice and expanded perlite aggregates were used in aggregate phase. Compressive strength and flexural tensile strength at 7, 28 and 90 days were determined on specimens were cured in water and air at the same ages. Obtained test results showed that SCLWC of 50 MPa compressive strength at 28 days can be produced by the use of lightweight aggregate and this concrete was not effect to curing condition as much as conventional concrete.
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