Experimental investigation of effect of tool path strategies and cutting parameters using acoustic signal in complex surface machining

High productive milling of complex sculptured surfaces is extremely important in many different industries. Determination of the appropriate tool path styles and milling parameters is crucial in ensuring precise surface machining, meeting the better surface integrities and lower tool deflection and forces using process monitoring methods. In this study, sound pressure as a monitoring method is presented for analyzing different tool path strategies and cutting parameters to assess their influence on surface errors, tool deflection, cutting forces, sound pressure level and instantaneous material removal rate on rough machining of complex surfaces with ball end mill. Design and analysis of experiments are performed using factorial design technique and variance analysis. Additionally, the significant parameters affecting the experimental results are introduced. B-rep based method with integrated CAM software is developed to calculate the cutter/workpiece engagement, effective cutting diameter and instantaneous material removal rate. Milling strategies employed include contour parallel, zigzag with two cut angle, and spiral. The milling conditions were feed rate and radial depth of cut. The conclusion is that 0° zigzag strategy provokes the lowest cutting forces, tool deflection, surface errors and sound pressure and spiral strategy signifies the worst surface errors and the highest cutting forces. With the increase of feed rate, instantaneous material removal rate increases parallel to rising of machining sound signal, milling forces, tool deflection and machining errors. It is observed that the step over value has less influence on the results. The sound pressure level which has a drastic reference to the material removal rate and removed volume values are detected and experimental results could be figured out with sound pressure

An Investigation of Turkish Language and Turkish Language and Literature Teacher Candidates’ Critical Reading Self-efficacy (The Case of Mehmet Akif Ersoy University)

The basic purpose of native language teaching is ensuring that students develop their skills in four basic language skills at an adequate level. For this purpose, Turkish Language and Turkish language and literature teachers who work in different teaching levels, especially classroom teachers, have important duties. Reading, which is among basic language skills, is a comprehension ability for individuals to reach new information and improve themselves. The thing that is important in reading is combining new information with previous information, and making sense of new information through previously learned information. A good reader should be able to make evaluations about text in a critical manner, in other words, s/he should be able to read critically. Turkish Language and Turkish Language and Literature teachers, who have the responsibility of giving students reading skills in formal education institutions, must have improved critical reading skills. In this study, the purpose was to determine the critical reading self-efficacy levels of Turkish Language and Turkish Language and Literature teacher candidates through some variables. The study data were collected by using the “Critical Reading Self-Efficacy Scale”. The SPSS 21.00 Program was used to analyze the data. From the analysis of the data, it was found that Turkish Language and Turkish Language and Literature teacher candidates have moderate critical self-efficacy levels. It was also observed that the critical reading self-efficacy perceptions of teacher candidates do not change according to gender; however, the reading self-efficacy perceptions of Turkish Language teacher candidates were found to be higher than that of the Turkish Language and Literature teacher candidates. It was also concluded that the critical reading self-efficacy perceptions of the teacher candidates, who said that they had reading habits, were higher than the teacher candidates, who said that they did not have reading habits

Non-extensive study of Rigid and Non-rigid Rotators

The isotropic rigid and non-rigid rotators in the framework of Tsallis statistics are studied in the high and low temperature limits. The generalized partition functions, internal energies and heat capacities are calculated. It has been found that results are in well agreement with the classical Boltzmann-Gibbs statistics in the limiting Tsallis index. It has also been observed that nonextensivity parameter q behaves like a scale parameter in the low temperature regime.Comment: 11 Pages, 3 Figures, Late

Quantum Mechanical Treatment of the Problem of Constraints in Nonextensive Formalism Revisited

The purity of Werner state in nonextensive formalism associated with two different constraints has been calculated in a previous paper by G. B. Bagci et al. [G. B. Bagci et al., Int. J. Mod. Phys. 20, 2085 (2006)]. Two different results have been obtained corresponding to ordinary probability and escort probability whereas the former has been shown to result in negative values thereby leading authors to deduce the advantage of escort probabilities over ordinary probabilities. However, this results have been only for a limited interval of q values which lie between 0 and 1. In this paper, we solve the same problem for all values of nonextensive index q by using a perturbative approach and show that the simultaneous use of both types of constraint is necessary in order to obtain the solution for whole spectrum of nonextensive index. In this sense, the existence of these different constraints in nonextensive formalism must not be seen as a deficiency in the formalism but rather must be welcomed as a means of providing solution for all values of parameter q.Comment: 7 page

Thermal analysis of a plastic helical coil heat exchanger for a domestic water storage tank

In the present study, the heat transfer coefficients of helically coiled corrugated plastic tube heat exchanger inside of the solar boiler vessel were investigated experimentally. The metal coil of the conventional solar boiler for domestic usage was replaced by a plastic tube and the results were compared with the numerical simulation and the technical documentation of the initial solar boiler. All the required parameters like inlet and outlet temperatures of tubeside and stratified temperatures, flow rate of fluids, etc. were measured using appropriate instruments. The test runs were performed for different temperatures inside the tank ranging from 30-60°C and different flow rates from which the heat transfer coefficients were calculated

Evaluation of Existing Reinforced Concrete Buildings with Structural Package Programs

Seismic performances of the structures shall be investigated due to lack of strength, seismic forces and change of intended purpose. Package softwares are developed to perform the complicated performance analyses easily. However, engineers must investigate the efficiency of these softwares. In this study, three different packaged softwares are used to compare the linear performance analyses according to Turkish Seismic Code-2007. Since non-linear performance analysis methods are not available in all programs, it is not taken into consideration in the scope of this study. Linear performance analysis of five different reinforced concrete (R/C) structures such as column-beam frame systems and systems with shear walls are analyzed and seismic performances are obtained. Furthermore, performance values are inclusively compared with figures. The reasons of the differences are presented. With the analyses, r values differ from each other. The main reason of this situation is the difference in remnant moment and efficient moment values. Modeling techniques also affect this case. According to the results, seismic performances of structures that have basic geometry, small sections and less irregularities are close each other. On the other hand, the results become different with the irregularity. Especially, seismic performances of the structures with shear walls differ from each other due to the various acceptances

Special Education Candidate Teachers’ Metaphors about Social Media

Because technology is developing each day and internet is getting easier to access, the types of communication among the people also have a constant alteration. Social media being one of the leads, especially the students undergoing an education frequently use these new communication styles. Studies in this context suggest that students do not use social media only to communicate with each other but also to exchange information, cooperate and share their class materials. In this regard, the perspectives of those who will be teaching students with special needs regarding social media are important to focus on. Therefore, this inquiry aims to identify the approaches of special education candidate teachers about social media courses through metaphors. The phenomenological research design was applied in this study. Participants were chosen from the candidate teachers who studied Special Education Teaching at Sakarya University Education Faculty in 2017 and 2018. The data was collected through the forms which had expressions as “because it is … social media is like … “and content analysis was used to examine this data. The forms were filled by 87 participants and the results show that they have developed 81 different metaphors. Based on the reasons for these metaphors researchers formed 6 categories: life colour, side effect, object, dependency, necessity and waste of time. It was also observed that the perspectives of special education candidate teachers about social media courses were typically positive

Evaluation of Existing Reinforced Concrete Buildings with Structural Package Programs

Seismic performances of the structures shall be investigated due to lack of strength, seismic forces and change of intended purpose. Package softwares are developed to perform the complicated performance analyses easily. However, engineers must investigate the efficiency of these softwares. In this study, three different packaged softwares are used to compare the linear performance analyses according to Turkish Seismic Code-2007. Since non-linear performance analysis methods are not available in all programs, it is not taken into consideration in the scope of this study. Linear performance analysis of five different reinforced concrete (R/C) structures such as column-beam frame systems and systems with shear walls are analyzed and seismic performances are obtained. Furthermore, performance values are inclusively compared with figures. The reasons of the differences are presented. With the analyses, r values differ from each other. The main reason of this situation is the difference in remnant moment and efficient moment values. Modeling techniques also affect this case. According to the results, seismic performances of structures that have basic geometry, small sections and less irregularities are close each other. On the other hand, the results become different with the irregularity. Especially, seismic performances of the structures with shear walls differ from each other due to the various acceptances

The Evaluation of CEIT Teacher Candidates in Terms of Computer Games, Educational Use of Computer Games and Game Design Qualifications

Computer games have an important usage potential in the education of today’s digital student profile. Also computer teachers known as technology leaders in schools are the main stakeholders of this potential. In this study, opinions of the computer teachers about computer games are examined from different perspectives. 119 computer teacher candidates participated in this study, and the data were collected by a questionnaire. As a result of this study, computer teacher candidates have a positive thinking about the usage of computer games in education and they see themselves qualified for the analysis and design of educational games. But they partially have negative attitudes about some risks like addiction and lose of time. Also the candidates who attended the educational game courses and play games from their mobile phones have more positive opinions, and they see themselves more qualified than others. Males have more positive opinions about computer games than females, but in terms of educational games and the analysis and design of the computer games, there is no significant difference between males and females.Bilgisayar oyunları, günümüz dijital öğrenci profilinin eğitiminde önemli bir kullanım potansiyeline sahiptir. Bu potansiyelin kullanımında öne çıkan bireylerden birisi de okullarda bir teknoloji lideri olan bilgisayar öğretmenleridir. Bu araştırmada, bilgisayar öğretmenlerinin bilgisayar oyunlarına yönelik görüşleri farklı boyutlardan ele alınmıştır. Araştırma kapsamında 119 bilgisayar öğretmen adayına ulaşılmış, geliştirilen anketle veri toplanmıştır. Araştırma sonucunda bilgisayar öğretmen adaylarının eğitsel anlamda bilgisayar oyunlarının kullanımı konusunda olumlu düşünceye sahip oldukları ve eğitsel oyunların tasarımı ve analizi konusunda kendilerini yeterli gördükleri, ancak bilgisayar oyunları konusunda bağımlılık riski, zaman kaybı gibi bazı konularda kısmen olumsuz görüşe sahip oldukları sonucuna ulaşılmıştır. Ayrıca eğitsel oyun dersi alan öğrenciler ile cep telefonundan oyun oynayan öğrencilerin bilgisayar oyunlarına yönelik bazı boyutlarda görüşlerinin daha olumlu olduğu ve kendilerini daha yeterli gördükleri sonucuna ulaşılmıştır. Cinsiyet açısından sadece bilgisayar oyunları geneli için erkekler kızlardan oyunlar konusunda daha olumlu görüş bildirirken, bilgisayar oyunlarının eğitim amaçlı kullanımı ve eğitsel oyunların tasarımı/analizi açısından bir farklılık bulunmamaktadır

Influence of pore density on thermal development in open-cell metal foam

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