161 research outputs found
General Rotational Surfaces with Pointwise 1-Type Gauss Map in Pseudo- Euclidean Space E42
In this paper, we study general rotational surfaces in the 4- dimensional
pseudo-Euclidean space E4-2 and obtain a characterization of flat general
rotation surfaces with pointwise 1-type Gauss map in E4-2 and give an example
of such surfaces.Comment: arXiv admin note: substantial text overlap with arXiv:1302.280
Flat Rotational Surfaces with Pointwise 1-Type Gauss Map Via Generalized Quaternions
In this paper,we determine a rotational surface by means of generalized quaternions and study this flat rotational surface with pointwise 1-type Gauss map in four-dimensional generalized space Eαβ4. Also, for some special cases of α and β, we obtain the characterizations of flat rotational surfaces with pointwise 1-type Gauss map in four-dimensional Euclidean space E4 and four-dimensional pseudo-Euclidean space E24. © 2018, The National Academy of Sciences, India
Nonisocyanate based polyurethane/silica nanocomposites and their coating performance
A series of silica nano-particles with different size were prepared by sol–gel technique, then surface modification by using cyclic carbonate functional organoalkoxysilane (CPS) was performed. Various amounts of carbonated silica particles directly added into carbonated soybean oil (CSBO) and carbonated polypropylene glycol (CPPG) resin mixture to prepare polyurethane–silica nanocomposite coating compositions by nonisocyanate route using an aliphatic diamine as a curing agent. Cupping, gloss, impact, and taber abrasion tests were performed on aluminum panels coated with those nano-composite formulations and tensile tests, thermogravimetric and SEM analyses were conducted on the free films prepared from the same coating formulations. An increase in abrasion resistance of CSBO-CPPG resin combination with the addition of silica was observed. In addition, the maximum weight loss of CSBO-CPPG resin combination was shifted to higher temperatures with incorporation of silica nano-particles The positive effect of modified silica particles on thermal stability of CSBO-CPPG system could be explained in such a way that PPG chains are able to disperse particles in the medium throughout the interactions between ether linkages and silanol groups
Türkiye’de Pazarlama İle İlgili Yayınlanan Makalelerin Bibliyometrik İncelenmesi Bibliometric Analysis of Published Marketing Articles in Turkey
Bu araştırmanın amacı; 2004-2016 yılları arasında pazarlama alanında yazılmış
makalelerin konu, araştırma yöntemi, yazar sayısı ve yerli-yabancı kaynak kullanım
miktarı dikkate alınarak tasnif edilmesidir. Bu kapsamda Türkiye Bilimsel ve
Teknolojik Araştırma Kurumu’na (TÜBİTAK) bağlı faaliyet gösteren Ulusal Akademik
Ağ ve Bilgi Merkezi (ULAKBİM) veri tabanında kayıtlı olan toplam 308 makale
incelemeye tabi tutulmuştur. Toplanan veriler bibliyometrik analiz yöntemi ile
sınıflandırılmıştır. Araştırmada kullanılan parametreler ise makalenin pazarlama
konusu, yayım yılı, yazar sayısı, sayfa sayısı, yerli - yabancı kaynak sayısı ve kullanılan
yöntemin (nicel veya nitel oluşu) şeklindedir. Araştırma sonuçlarına göre en çok
çalışılan konular; “pazarlama yönetimi ve stratejisi”, “pazarlama iletişimi”, “sosyal
pazarlama ve yeşil pazarlama” şeklindedir. En az araştırma ise “veri tabanlı
pazarlama”, “sanat pazarlaması” ve “perakendecilik” alanlarında yapılmıştır. Ayrıca
araştırmanın diğer sonuçlarına göre iki yazarlı ve tek yazarlı makalelerin daha fazla
olduğu, yabancı kaynakların daha fazla kullanıldığı, makalelerin ortalama 17 sayfa
yazıldığı, nicel araştırma yöntemlerinin daha fazla kullanıldığı saptanmıştır.
The aim of this study is to classify articles written in marketing field between
2004-2016 by considering the topic, research method, number of author and amount of
domestic-foreign resource usage. In this context, A total of 308 articles were reviewed
which registered in the database Turkish Academic Network And Information Center
(ULAKBIM) which is affiliated with The Scientific And Technological Research Council
Of Turkey (TUBITAK). The collected data were classified by bibliometric analysis
method. The parameters used in the research are marketing theme of the article, the
year of publication, the number of authors, the number of pages, the number ofdomestic-foreign resources and the methods used (quantitative and/or qualitative).
According to the results of the research, the most studied topics are; "Marketing
management and strategy", "marketing communication", "social marketing and green
marketing". The least research has been made on "Database marketing", "art
marketing" and "retailing". In addition, some other results of this research are that two
author articles and single author articles has been more frequent, foreign sources were
used more frequently, the articles were 17 pages in average, quantitative research
methods were used more commonly
Optimization of machining parameters in face milling using multi-objective Taguchi technique
In this research, the effect of machining parameters on the various surface roughness characteristics (arithmetic average roughness (Ra), root mean square average roughness (Rq) and average maximum height of the profile (Rz)) in the milling of AISI 4140 steel were experimentally investigated. Depth of cut, feed rate, cutting speed and the number of insert were considered as control factors; Ra, Rz and Rq were considered as response factors. Experiments were designed considering Taguchi L9 orthogonal array. Multi signal-to-noise ratio was calculated for the response variables simultaneously. Analysis of variance was conducted to detect the significance of control factors on responses. Moreover, the percent contributions of the control factors on the surface roughness were obtained to be the number of insert (71.89 %), feed (19.74 %), cutting speed (5.08%) and depth of cut (3.29 %). Minimum surface roughness values for Ra, Rz and Rq were obtained at 325 m/min cutting speed, 0.08 mm/rev feed rate, 1 number of insert and 1 mm depth of cut by using multi-objective Taguchi technique
Modeling and optimization of face milling process parameters for AISI 4140 steel
In this study, the effect of cutting parameters such as the depth of cut, feed rate, cutting speed and the number of inserts on surface roughness were investigated in the milling of the AISI 4140 steel. The optimal control factors for surface quality were detected by using the Taguchi technique. Experimental trials were designed according to the Taguchi L18 (2¹x3³) orthogonal array. The statistical effects of control factors on surface roughness have been established by using the analysis of variance (ANOVA). Optimal cutting parameters were obtained by using the S/N ratio values. The ANOVA results showed that the effective factors were the number of inserts and the feed rate on surface roughness. However, the depth of cut and the cutting speed showed an insignificant effect. Additionally, the First-order and Second-order regression analysis were conducted to estimate the performance characteristics of the experiment. The acquired regression equation results matched with the surface roughness measurement results. The optimal performance characteristics were obtained as a 0.5 mm depth of cut, 0.08 mm/rev feed rate, 325 m/min cutting speed and 1 number of inserts by using the Taguchi method. Additionally, the confirmation test results indicated that the Taguchi method was very prosperous in the optimization of the machining parameters to obtain the minimum surface roughness in the milling of the AISI 4140 steel
Telerehabilitasyon: Deprem Sonrası Rehabilitasyon İçin Umut Vadeden Bir Çözüm
Telerehabilitation, the use of telecommunication technologies to provide rehabilitation services to individuals remotely, has emerged as a promising solution for postearthquake rehabilitation. Earthquakes can cause severe physical and psychological damage, and the affected individuals often require rehabilitation services to recover. However, the traditional delivery of rehabilitation services may not be feasible in postearthquake scenarios due to the destruction of infrastructure and limited availability of healthcare providers. Telerehabilitation offers a cost-effective and accessible alternative for providing rehabilitation services in such situations. This review article explores the current state of telerehabilitation in post-earthquake scenarios. It discusses the advantages and challenges of telerehabilitation and presents examples of successful implementation in earthquake-affected areas. The article also examines the effectiveness of telerehabilitation in various domains. The article highlights the importance of proper planning and infrastructure for successful implementation of telerehabilitation. It also emphasizes the need for training healthcare providers and patients to effectively use telecommunication technologies for rehabilitation services. The advantages of telerehabilitation, including cost-effectiveness and accessibility, make it a viable alternative to traditional rehabilitation services. However, successful implementation requires proper planning, infrastructure, and training. Further research is needed to explore the effectiveness of telerehabilitation in various post-earthquake scenarios and to address its ethical and legal implications
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