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Styryl-based new organic chromophores bearing free amino and azomethine groups: synthesis, photophysical, NLO, and thermal properties
No full textHerein we report the synthesis and characterization of a new series of
styryl-based push-pull dyes containing a free amino group and their
Schiff base derivatives. The dyes include the dicyanomethylene group as
an acceptor and different para-substituted alkylamines as donors.
Morever as a proton-sensitive group a pyridin-2-yl substituent was
attached to the para-position of the phenyl moiety in both series of
compounds. The photophysical properties of the dyes were examined in
various solvents with different polarities and showed absorption in the
visible region and green-red emission with low quantum yields. The
absorption and the emission maxima were shifted bathocromically by
increasing the solvent's polarity. However, there was no correlation
with the polarity parameters of the solvents. The pH-sensitive
properties of all prepared Schiff bases were examined against TBAOH in
DMSO, via deprotonation of the OH group in the salicylidene moiety and
their reverse protonation was also investigated using TFA. The Schiff
bases exhibited a bathochromic shift upon the addition of TBAOH to their
solutions in DMSO. Therefore, they showed potential to be utilized as
colorimetric and luminescence pH sensors. The second-order nonlinear
optical (NLO) responses of the dyes were measured by the electric
field-induced second harmonic (EFISH) generation method. The highest mu
beta values were obtained for the dyes bearing the julolidine donor as
1430 x 10(-48) esu (for free amino derivative) and 1950 x 10(-48) esu
(for Schiff base derivative), respectively. The structural and
electronic properties of the dyes as well as their NLO properties were
further studied using DFT calculations. The thermal stabilities of all
dyes were evaluated by thermogravimetric analysis (TGA). The TGA data
showed that all dyes were thermally stable up to 250 degrees C
Application of Response Surface Methodology for Removal of Remazol Yellow (RR) by Immobilised S. cerevisiae on Pumice Stone
No full textIn this study, Remazol Yellow (RR) removal was investigated by
Saccharomyces cerevisiae immobilized on pumice stone. For immobilization
process new technic was used and immobilization matrix HCl pretreated
pumice stone was added to growth medium of microorganism. pH, initial
biosorbent (C-o) and dye concentration (C-b) effect on biosorption were
optimized through the Response Surface Methodology (RSM) and second
order quadratic model was used to describe the effects ofparameters
successfully. At optimum conditions pH 3, C-b 2.5 g/L, C-0 400 ppm
maximum dye removal was 99\% and 140 mg/g capasity was catched. When
pumice stone, HCl preated pumice stone and Saccaharomyces cerevisiae
were used in biosorption experiments directly 44\%, 69\%, 75\% dye
removal was obtained respectively. 0.5 M NaOH (pH 13.69) and water (pH
8) were chosen as a desorption agent for the immobilised biosorbent.
Desorption efficiency was found 21\% with 0.5 M NaOH and 1.5\% with
water (pH 8). The characterization studies were performed by using
Scanning Electron Microscope (SEM) and Fourier Transformer InfraRed
(FT-IR) spectroscopy. The results indicate that immobilised biosorbent
is a promising alternative for the biosorption of Remazol Yellow (RR)
from aqueous solutions
Epidemiological features of primary glomerular disease in Turkey: a multicenter study by the Turkish Society of Nephrology Glomerular Diseases Working Group
No full textDesıgn, Inductance Calculatıon And Implementatıon Of Hexagonal Coıl For Wıreless Power Transfer Systems
No full textKablosuz Güç Aktarım (KGA) sistemleri farklı güç seviyelerindeki batarya şarj işlemleri için temiz, güvenilir ve kolay bir yöntem olması nedeniyle gün geçtikçe daha yaygın bir kullanım alanına sahip olmaktadır. Literatürde, KGA sistemlerinde kullanılmak üzere birçok sargı yapısı önerilmiştir. Bunlardan biri olan altıgen sargı yapısı yüksek bağlaşım katsayısı, uygulama kolaylığı ve özellikle çoklu sargı yapılarında efektif alan kullanımı nedeniyle özellikle küçük güçlü uygulamalarda sıkça kullanılmıştır. Ancak bu sargı yapısının öz ve ortak endüktans değerlerinin hesaplanabilmesine yönelik kısıtlı çalışmalar mevcuttur ve bu çalışmalar genellikle birden fazla katsayının kullanıldığı karmaşık integral çözümlemeleri içermektedir. Öte yandan elektrikli araç bataryalarının şarjı gibi yüksek güçlü uygulamalarda ise kullanımına ilişkin çalışmalar ise yok denecek kadar azdır. Literatürdeki bu boşluğu doldurmak için, öncelikle altıgen bir sargının öz ve ortak endüktans hesaplamalarında akı dağılımlarının elde edilebilmesi için Biot-Savart Kuralı temel alınarak tek bir temel manyetik akı yoğunluğu denklemi kullanılmış ve geliştirilen algoritma yardımıyla en az hata ile endüktans hesaplamalarının yapılabilmesi için yeni bir nümerik yöntem önerilmiştir. Önerilen nümerik yöntemin doğrulanabilmesi için 10 cm ve 20 cm kenar uzunluklarına sahip altıgen sargılar 1.78 mm2 iletken kesitine sahip litz teli kullanılarak üretilmiş ve endüktans değerleri ölçülmüştür. Önerilen nümerik yöntem sonuçları mevcut yöntemler, benzetim çalışmaları ve ölçüm sonuçları ile karşılaştırılarak doğruluğu gösterilmiştir. Elde edilen endüktans formülleri kullanılarak 1 kW gücünde bir KGA sistem tasarımı gerçekleştirilmiş ve bu tasarım benzetim ve uygulama sonuçları ile doğrulanmıştır. Endüktans hesaplamalarının ölçüm sonuçları ile karşılaştırıldığında büyük oranda örtüştüğü görülmüştür. 1 kW gücündeki uygulama sonuçlarına göre %85 verimle 10 cm’lik bir hava aralığından kablosuz güç aktarımı başarılmıştır. Ayrıca daha iyi bir bağlaşım katsayısına sahip çift primer sargı yapısı önerisi yapılmış, benzetim ve deneysel sonuçlar verilmiştirWireless Power Transfer (WPT) systems are becoming more popular since it is a clean, reliable and easy method for battery charging at different power levels. In the literature, several coil structures have been proposed for use in WPT systems. One of them, hexagonal coil, is frequently used especially in low power applications due to its high coupling coefficient, ease of application and effective use of space especially in multiple coil structures. However, there are limited work to calculate the self and mutual inductance values for this coil structure and these work have complicated process which require complex integral solutions by using several coefficients. On the other hand, in high-power applications such as charging of electric vehicle batteries, its use is very rare. In order to fill this knowledge gap, a new analytical method has been proposed in this thesis. A single basic magnetic flux density equation which is based on Biot-Savart Law was used in order to obtain flux distribution in a hexagonal coil for the self and mutual inductance calculations. In order to verify the results obtained with the analytical approach, two hexagonal coils with 10 and 20 cm outer side lengths were produced by using litz wire with a conductive cross section of 1.78 mm2. The results obtained with the new approach are compared with the Finite Element Analysis results, the other work presented in the literature and experimental results in order to prove the accuracy of the proposed method. The obtained inductance equations have been used to design a 1 kW WPT system with hexagonal coils. The theoretical and simulation results have been validated with an implementation in the laboratory and a DC-to-DC power efficiency of 85% is achieved across a 10 cm air gap between the coils. Furthermore, a novel double primary coil design is proposed in order to increase coupling coefficient and the proposed model has been validated by simulation and experimental result
Akıllı Ülkeler: İsviçre, Bosna Hersek ve Türkiye Kıyaslaması ve Türkiye’nin Akıllı Ülke Performans Analizi
No full textAstragalus bartinense (Fabaceae), a new species from Turkey
No full textAstragalus bartinense is described as a new species from Bartin Province
in Northern Anatolia, Turkey. The new species is close to A. depressus
L. and A. froedinii Murb., but distinctly differs from A. froedinii in
having hairy fruit, long stipules (10-12 mm) and peduncle (10-25 mm). It
also differs from A. depressus in having long stipules and a stipitate
and glabrous ovary. Taxonomic descriptions, micromorphology of pollen
and seed and geographical distribution are presented
The Impact of Immediate Vicinity Training on Academic Success and Environmental Attitudes of the Fourth Graders in the Primary School
No full textThis research seeks to increase the knowledge of the fourth graders in
primary school and their attitudes towards the environment positively
through immediate vicinity education. The research was carried out with
the experimental design of the pre-test-post-test control group with the
participation of 44 fourth graders in a private school located in the
centre of Ankara. The data were obtained by applying ``Ankara
Environmental Booklet Achievement Test (AEBAT) and Environmental
Attitude Scale (EAS){''} as a pre-test and post-test to the experimental
and control groups. ``A Two-Factor ANOVA for Mixed Measurements{''} was
used to compare pre-test and post-test scores. After the completion of
the education process, a significant increase was found both in the
AEBAT and in the EAS scores in the experimental group who were trained
with Ankara Environmental Booklet and continued their official
curriculum in the post-tests. However, no significant change was
observed between the AEBAT and the EAS scores of the control group, who
were only attending to the official curriculum, which did not receive
any immediate vicinity education. It was concluded that there was no
significant change in the knowledge level of the students regarding the
immediate vicinity and their positive attitudes towards their
environment in the control group while experimental group has developed
both their academic success regarding their immediate vicinity and
positive attitude towards the environment
Determınatıon Of The Source Of Out Of Control Sıgnals In Multıvarıate Statıstıcal Processes
No full textİlişkili kalite değişkenlerinin söz konusu olduğu çok değişkenli süreç kontrolünde, süreç
dağılımının davranışını izlemek için çeşitli koşullar için geliştirilmiş çok değişkenli kontrol
grafikleri mevcuttur. Bunların en bilinenlerinden birisi çok değişkenli dağılımın ortalama
vektöründeki farklılaşmayı yakalamada kullanılan Hotelling 2 T kontrol grafiğidir. Ancak,
Hotelling 2 T gibi geleneksel yöntemler çok değişkenli dağılım fonksiyonunun normal
olmasını gerektirir ve genellikle dağılım ortalamasındaki görece büyük kaymaları
yakalamakta başarılıdır. Çok değişkenli süreç kontrolü durumunda dağılım parametre
vektöründeki anlamlı farklılaşmayı yakalamak kadar, bu kaymaya temelde neden olan
marjinal dağılımın hangi değişken/değişkenlere ait olduğunun bilinmesi de önemlidir. Bu
konuda geliştirilmiş çeşitli yöntemler olmakla birlikte, kaymaya neden olan değişkeni
belirlemede değişken sayısının artması bu yaklaşımları yetersiz kılabilmektedir. Bu
noktadan hareketle çalışmada çok değişkenli süreç kontrolünde geleneksel yöntemlerin
kısıtlarını ve yetersizliklerini ortadan kaldırmak amacıyla, bağımsız bileşenler analizi,
destek vektör makineleri ve hibrit bağımsız bileşenler analizi-destek vektör makineleri
temelinde özgün bir yaklaşımla ele alınmıştır. Buna uygun olarak analizler çok değişkenli
normal dağılıma uyan ve uymayan senaryolarda üretilen süreçler için simülasyon çalışması
yapılarak gerçekleştirilmiştir. Sonuçlar önerilen yöntemlerin geleneksel yöntemlerin kısıt ve
eksikliklerine karşılık önemli üstünlüklerinin olduğunu göstermektedir.Multivariate statistical process control charts are widely used to detect shifts in processes
where more than one inter-related quality variables. Shewhart type control charts, like
Hotelling 2 T control chart, which has an important place in the literature, capable to detect
the change in the process mean. However, traditional methods have constraints such that the
change in small shifts cannot be detected and requires the assumption of normality. Although
traditional methods can detect shifts in the process, it is not sufficient to determine the
variables or variables that cause shifts. From this point of view, in the multivariate process
control has been handled with a unique approach on the basis of independent components
analysis, support vector machines and hybrid independent components analysis-support
vector machines in order to eliminate the constraints and deficiencies of traditional methods.
Accordingly, the analyzes were carried out by simulation studies were carried out for the
data generated in one scenario for Gaussian and in three different scenarios for the non-
Gaussian processes. The results show that the proposed methods have significant advantages
over the constraints and shortcomings of traditional method