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Simple and cost-effective wavelength measurement system using photodiode pair: Applications in fiber coupled light sources
No full textDetermination of wavelength of any light source plays a crucial role for the application areas. In this work, we designed a simple and cost effective wavelength measurement system depending on two photodiodes and an amplifier circuit. Firstly, the wavelength response of the developed measurement system was determined using a monochromator. These results showed that, there was a linear relationship between the wavelength variation and the output of the developed system. Then, the wavelength shift of the laser diodes with respect to the changes in the operating temperature was obtained by a spectrometer. After the determination of the wavelength shift, same measurements were performed using our measurement setup. The wavelength shift of the laser diodes depending on temperature was found to be in a good agreement with the value obtained from the spectrometer measurements and the values given in datasheets of the laser diodes. Finally, the change in the output voltage of the system was investigated according to the optical power of the laser beam. The findings suggest that, proposed measurement system can be a simple alternative for the wavelength measurements and as well as color detection
Multi-criteria decision-making (mcdm) model for building damages in the Kahramanmaraş 2023 earthquakes sequence based on soil, ground motion and earthquake source-path parameters
No full textThis paper has attempted to determine the weighting levels of the soil and ground motion parameters (engineering bedrock depth (EBd), average shear wave velocity (Vs30), fundamental frequency (f0), peak ground acceleration (PGA), Joyner-Boore distance (Rjb), and epicenter distance (Repi)) in reflecting the actual damage status after the 2023 Kahramanmara & scedil; earthquakes, which have a wide impact area of 11 provinces. The analytical hierarchy method (AHP), a multi-criteria decision-making (MCDM) process, was used to analyze these parameter data sets obtained from 44 Disaster and Emergency Management Presidency of T & uuml;rkiye (AFAD) stations (Gaziantep, Hatay, Kahramanmara & scedil;, and Osmaniye). The priority order of the parameters before the analysis was systematically collected. These parameters were categorized into soil, ground motion and earthquake source-path properties. Considering the literature, these characteristics and their combined effects were systematically weighted with AHP under five groups. According to the weighted groups in the scope of the study, the actual damage data can be determined with a minimum accuracy rate of 70% (Group 1). In comparison, the best performance evaluation was 82% (Group 5). The parameter order and weights in the actual damage data evaluation are suggested as EBd-%28, PGA-%24, Vs30-%19, Rjb-%14, f0-%10, and Repi-%5 considering the very high accuracy rate of Group 5. This suggested weighting allows the rapid and effective estimation of the damage distribution after a possible earthquake only with soil, ground motion and earthquake source-path characteristics, even in cases where reliable structure data cannot be obtained.Funding agency
Sakarya Universit
Real-world insights from Türkiye: Biologic DMARDs usage in spondyloarthritis patients with chronic kidney disease
No full textAimThe objective was to evaluate biologic disease-modifying antirheumatic drugs (DMARDs) and their side effects that hindered the continuation of treatment in a patient population diagnosed with spondyloarthritis (SpA) with a glomerular filtration rate (GFR) <= 60 mL/min, and to compare these side effects between patients with chronic kidney disease (CKD) and those without.MethodsThis multicenter, observational cohort study utilized data from the TReasure database, which records SpA patients in a web-based system across T & uuml;rkiye. A total of 6052 patients being included. SpA patients were categorized into two main groups: non-CKD patients and CKD patients. The clinical characteristics, disease activity, treatment options, drug retention rates, reasons for drug discontinuation, and types of adverse effects were compared between the groups.ResultsBiologics prescription pattern varied between CKD and non-CKD patients. Etanercept was prescribed more frequently (53.1%) in CKD patients. Regarding the number of side effects and drug discontinuations in CKD patients, no statistically significant differences were found between the non-CKD and CKD groups for any of the bDMARDs (adalimumab, etanercept, golimumab, infliximab, ustekinumab, secukinumab, and certolizumab). No statistically significant differences were observed in the duration of drug retention based on CKD status for bDMARDs.ConclusionThis study offers preliminary evidence supporting the effective and safe use of bDMARDs in patients with SpA and CKD
An examination of the effect of motivation on job involvment among freelancers
No full textBu araştırmanın amacı, freelance çalışanların motivasyon düzeylerinin işe bağlılık üzerindeki etkisini incelemektir. Dijitalleşme ve esnekleşme gibi gelişmeler, geleneksel çalışma biçimlerini dönüştürerek freelance modeli yaygınlaştırmıştır. Örgütsel yapılardan bağımsız çalışan bireylerin işlerine olan bağlılıklarını belirleyen temel faktörlerden biri motivasyondur. Bu doğrultuda çalışmada, motivasyonun çok boyutlu yapısının işe bağlılık üzerindeki etkisi analiz edilmiştir. Birinci bölümde, tarihsel süreç içerisinde çalışma biçimlerinin evrimi ve freelance çalışmanın kavramsal çerçevesi ele alınmıştır. İkinci bölümde motivasyon kavramı, araçları ve kuramsal yaklaşımlar; üçüncü bölümde işe bağlılık kavramı, boyutları ve etkileyen faktörler açıklanmıştır. Dördüncü bölümde ise araştırmanın yöntemi, analizleri ve bulgularına yer verilmiştir. Araştırma, çeşitli mesleklerde freelance çalışan 132 kişiden elde edilen verilerle yürütülmüş, analizler SPSS 27.0 programı ile gerçekleştirilmiştir. Regresyon analizine göre, içsel motivasyon ve dışsal düzenleme–maddesel alt boyutlarının işe bağlılık üzerinde anlamlı ve pozitif etkisi olduğu bulunmuştur. Diğer alt boyutlar anlamlı etkiler göstermemiştir. Ayrıca cinsiyet, eğitim durumu ve medeni durum değişkenlerine göre motivasyon ve işe bağlılık düzeylerinde anlamlı farklılıklar saptanmıştır.The primary purpose of this study is to examine the effect of motivation levels on job involvment among freelancers. With the rise of digitalization and flexibility, traditional employment models have been reshaped, and freelance working has become increasingly widespread. Motivation is considered one of the key factors influencing freelancers’ psychological commitment to their work. In this context, the multidimensional structure of motivation and its impact on work engagement are analyzed. The first chapter discusses the historical evolution of working patterns and the conceptual foundations of freelance work. The second chapter addresses the concept of motivation, motivational tools, and relevant theoretical approaches. The third chapter focuses on the definition, dimensions, and determinants of work engagement. The final chapter presents the methodology, analyses, and findings of the empirical research. The data were collected through an online survey from 132 freelance employees working in various profession and analyzed using SPSS 27.0 software. According to the results of the regression analysis, intrinsic motivation and external regulation–material sub-dimensions were found to have a significant and positive effect on work engagement. Other sub-dimensions did not show statistically significant effects. Additionally, significant differences in motivation and work engagement levels were identified based on gender, educational background, and marital status
Thermal vibration analysis of short-fiber-reinforced nanobeams with deformable boundaries in an elastic medium
No full textBu tez çalışmasında, uçları elastik yaylarla sınırlandırılmış ve elastik bir zemin üzerinde yer alan kısa fiber takviyeli bir nanokirişin termo-mekanik serbest titreşim davranışı analitik olarak incelenmektedir. Matris içerisinde rastgele dağılmış kısa fiberlerden oluşan nanokirişin etkin malzeme özellikleri Halpin–Tsai modeli kullanılarak tanımlanmıştır. Kirişin her iki ucu elastik yaylarla modellenmiş olup, bu sayede hem rijit hem de deformasyona izin veren sınır koşullarının etkileri birlikte incelenebilmektedir. Ayrıca, elastik Winkler temeli üzerinde bulunan nanokiriş, EulerBernoulli kiriş teorisi ile modellenmiş ve yönetici denklemler Hamilton prensibi uygulanarak elde edilmiştir. Boyut etkileri ise, hem yerel olmayan hem de malzeme uzunluk ölçek parametrelerini içeren yerel olmayan gerinim gradyan teorisi kapsamında ele alınmıştır. Çalışmada, Fourier sinüs serileri ve Stokes dönüşümüne dayalı genel bir çözüm yöntemi geliştirilmiş ve ortaya çıkan özdeğer problemi çözülerek nanokirişin doğal frekansları elde edilmiştir. Sayısal sonuçlar; Winkler temelinin rijitliği, uçlardaki yay katsayıları, malzeme uzunluk ölçeği parametresi, fiber boy/çap oranı ve fiber/matris elastik modül oranının artmasının doğal frekansları yükselttiğini göstermektedir. Öte yandan, sıcaklık yüklerinin, yerel olmayan parametrenin ve fiber/matris yoğunluk oranının artmasının frekanslar üzerinde zayıflatıcı etkiler yarattığı görülmektedir.In this thesis, the thermo-mechanical free vibration behavior of a short-fiber-reinforced nanobeam, which is restrained by elastic springs at both ends and embedded in an elastic foundation, is analytically investigated. The effective material properties of the nanobeam, composed of randomly distributed short fibers within a matrix, are defined using the Halpin–Tsai model. By modeling both ends of the beam with elastic springs, the effects of both rigid and deformable boundary conditions can be simultaneously examined. In addition, the nanobeam resting on an elastic Winkler foundation is modeled using the Euler-Bernoulli beam theory, and the governing equations are obtained by applying Hamilton's principle. Size effects are considered within the framework of the nonlocal strain gradient theory, which incorporates both nonlocal and material length scale parameters. A general solution method based on Fourier sine series and Stokes' transform is developed in the study, and by solving the resulting eigenvalue problem, the natural frequencies of the nanobeam are obtained. Numerical results show that increasing the stiffness of the Winkler foundation, the stiffness of the boundary springs, the material length scale parameter, the fiber length-to-diameter ratio, and the fiber-to-matrix Young’s modulus ratio leads to an increase in natural frequencies. On the other hand, it is observed that an increase in the thermal loads, the nonlocal parameter, and the fiber-to-matrix mass density ratio have a weakening effect on the frequencies
The relationship between brain drain and human capital: evidence from Turkey
No full textPurpose: This study investigates the relationship between brain drain and human capital in Turkey from 1984 to 2022. It aims to identify the macroeconomic and institutional factors influencing skilled labour migration and assess their impact on human capital. The study offers policy recommendations to mitigate brain drain based on the findings.Design/methodology/approach: The study employs the Bai and Perron method to analyse the relationship between brain drain and human capital in Turkey, focusing on economic and institutional factors using annual data from 1984 to 2022. The model estimates structural breaks to capture the time-varying effects of these factors. Findings: The model estimation reveals significant structural breaks in 1994 and 2006. Notably, the increase in human capital from 2006 to 2022 was associated with a rise in brain drain. The findings indicate that macroeconomic factors are the most critical determinants of brain drain, with institutional factors also exerting a significant impact across all sub-periods.Originality/value: This study represents a pioneering effort in Turkey, offering the first comprehensive analysis of the relationship between brain drain and human capital. Integrating econometric methodology with macroeconomic and institutional factors provides a novel and holistic framework for understanding this critical issue. The study provides strategic recommendations for policymakers to preserve Turkey's human capital and prevent brain drain
Effects of irrigation level, planting density and nitrogen doses on grain yield and yield components in sweet sorghum
No full textBursa ekolojik koşullarında kurulan bu araştırmanın amacı farklı sulama seviyeleri, ekim sıklıkları ve azot dozlarının tatlı sorgum üretiminde yüksek verim ve kaliteli verim öğeleri elde edecek uygulamaları belirlemektir. Denemeler 2022 ve 2023 yıllarında Bursa Uludağ Üniversitesi Uygulama ve Araştırma Merkezi’nin deneme alanlarında yürütülmüştür. Denemelerde dört farklı sulama seviyesi (%0 ETc (bitki su tüketimi), %33 ETc, %66 ETc ve %100 ETc), iki farklı bitki sıklığı (14286 bitki/da ve 28571 bitki/da), dört farklı azot dozu (0 kg/da, 7 kg/da, 14 kg/da ve 21 kg/da) kullanılmıştır. Araştırmalar, Tesadüf Blokları Deneme Deseninde Bölünen Bölünmüş Parseller Deneme Düzenine göre yürütülmüş ve 3 tekerrürlü olarak planlanmıştır. Çalışmalarda ana parsellere sulama seviyeleri, alt parsellere bitki sıklıkları ve altın altı parsellere azot dozları yerleştirilmiştir. Sonuçlara göre, ana faktörler ve interaksiyonlarının incelenen tüm özellikler üzerinde önemli etkileri olduğu belirlenmiştir. Bursa koşullarında değişen iklim şartları altında incelenen tüm özellikler ile ilgili susuz parsellere karşılık sulanan parseller arasında önemli farklılıklar ortaya çıkarmış ve en yüksek değerler %100 ETc sulama seviyesinden elde edilmiştir. Bursa koşullarında 14286 bitki/da düşük bitki sıklığı salkımda tane ağırlığı ve bin tane ağırlığını en üst seviyeye taşırken, en yüksek tane verimi 28571 bitki/da bitki sıklığından elde edilmiştir. Farklı etkilere sahip azot dozlarında en yüksek tane verimi 21 kg/da azot dozunda tespit edilmiştir. Araştırmada, ikili interaksiyonlar incelendiğinde, 28571 bitki/da bitki sıklığı ve artan sulama seviyelerinin etkileşimi ile tane veriminde artış gözlenmiştir, en yüksek tane verimini 1653 kg/da ile yağışlı geçen 2022 yılında 28571 bitki/da bitki sıklığı ve %100 ETc sulama seviyesi interaksiyonundan elde edilirken, kurak geçen 2023 yılında 28571 bitki/da bitki sıklığı ve %33 ETc sulama seviyesi interaksiyonundan elde edilmiştir. Yağışın fazla olduğu 2022 yılında tüm azot dozlarında sulama seviyesi arttıkça tane verimi de artış göstermiştir ancak kurak iklime sahip 2023 yılında sulama seviyesi ve azot dozunun birlikte artması tane verimini iki yönlü arttırmıştır. Bitki sıklığı ile azot dozlarının interaksiyonunda, en yüksek tane verimi 28571 bitki/da bitki sıklığı ve 21 kg/da azot dozunun etkileşiminde belirlenmiştir. Üçlü interaksiyonlar sonucu, tane verimi bakımından farklı iklime sahip iki deneme yılında benzer sonuçlar elde edilse de 2022 yılında %100 ETc sulama seviyesi, 28571 bitki/da bitki sıklığının 0 kg/da ve 14 kg/da azot dozlarının interaksiyonlarında en yüksek değer elde edilirken, 2023 yılında %66 ETc ve %100 ETc sulama seviyelerinin, 28571 bitki/da bitki sıklığında, 21 kg/da azot dozu ile girdikleri etkileşim sonucu en yüksek değer elde edilmiştir.The aim of this research, which was established under Bursa ecological conditions, was to determine the applications of different irrigation levels, planting frequencies and nitrogen doses to obtain high yield and quality yield components in sweet sorghum production. The trials were conducted in 2022 and 2023 in the experimental fields of Bursa Uludağ University Application and Research Center. Four different irrigation levels (0% ETc (crop evapotranspiration), 33% ETc, 66% ETc and 100% ETc), two different plant densities (14286 plants/da and 28571 plants/da), four different nitrogen doses (0 kg/da, 7 kg/da, 14 kg/da and 21 kg/da) were used. The studies were planned in a randomized block design with 3 replications using a split-plot experimental design. Irrigation levels were placed in main plots, plant densities in sub-plots and nitrogen doses in sub-plots. According to the results, it was determined that the main factors and their interactions had significant effects on all traits examined. Under varying climatic conditions in Bursa conditions, there were significant differences between irrigated plots and non-irrigated plots for all traits examined and the highest values were obtained from 100% ETc irrigation level. Under Bursa conditions, the highest grain yield was obtained from plant density of 28571 plants/da, while the highest grain yield was obtained from plant density of 14286 plants/da. In nitrogen doses with different effects, the highest grain yield was obtained at 21 kg/da nitrogen. In the study, when the binary interactions were analyzed, an increase in grain yield was observed with the interaction of plant density of 28571 plants/da and increasing irrigation levels, the highest grain yield of 1653 kg/da was obtained from the interaction of plant density of 28571 plants/da and 100% ETc irrigation level in the wet year 2022, while it was obtained from the interaction of plant density of 28571 plants/da and 33% ETc irrigation level in the dry year 2023. In 2022, when rainfall was high, grain yield increased as irrigation level increased in all nitrogen doses, but in 2023, which had a dry climate, the increase in irrigation level and nitrogen dose together increased grain yield in both directions. In the interaction of plant density and nitrogen doses, the highest grain yield was determined in the interaction of 28571 plant/da plant density and 21 kg/da nitrogen dose. As a result of triple interactions, although similar results were obtained in two experimental years with different climates in terms of grain yield, the highest value was obtained in the interactions of 100% ETc irrigation level, 28571 plant/da plant density, 0 kg/da and 14 kg/da nitrogen doses in 2022, while the highest value was obtained as a result of the interaction of 66% ETc and 100% ETc irrigation levels, 28571 plant/da plant density and 21 kg/da nitrogen dose in 2023
Gut health for two: The critical role of probiotics and prebiotics in pregnancy and lactation
No full textPurpose of ReviewThis review summarizes current research on the effects of probiotics and prebiotics during pregnancy and lactation.Recent FindingsDuring pregnancy and lactation, various changes occur in maternal hormone levels and physiological processes to ensure the most favorable intrauterine environment. These changes may vary depending on factors such as maternal nutritional status and mode of delivery, and they can also lead to alterations in the maternal gut microbiota, breast milk microbiota, and neonatal gut microbiota. In this context, probiotic and prebiotic supplementation is considered to have potential benefits in preventing adverse outcomes during pregnancy and lactation. A literature review reveals that while prebiotic studies remain limited, probiotic research is comparatively more extensive. Current evidence suggests that probiotic, prebiotic, and synbiotic supplementation during pregnancy may exert beneficial effects on the prevention or mitigation of conditions such as gestational diabetes, maternal obesity, atopic dermatitis, and eczema, and positively influencing the composition of the vaginal microbiota. These outcomes are further supported during lactation by positive changes in the breast milk microbiota, improvements in conditions such as mastitis and breast pain, reduced risk of necrotizing enterocolitis, late-onset sepsis, and infantile colic, as well as a decrease in the frequency of infant crying.SummaryAlthough probiotic and prebiotic supplements are considered promising approaches to preventing health problems specific to pregnancy and lactation, there is a need for more methodologically sound, long-term, and randomized controlled studies in this field. Thus, the safety, efficacy, and place of these supplements in clinical practice can be demonstrated
Efficacy and immunologic effects of a synbiotic in children with functional abdominal pain
No full textBackground: The objective of this study was to examine the efficacy of a synbiotic in addressing recurrent abdominal pain in children, including functional abdominal pain, and to assess its impact on serum levels of pro-inflammatory and anti-inflammatory cytokines. Methods: We included 80 patients diagnosed with Functional Abdominal Pain Not Otherwise Specified according to the Rome IV criteria and divided the sample into two groups: the synbiotic group (Lactobacillus helveticus, Lactobacillus casei, Bifidobacterium lactis, chicory inulin) (Group 1) and the placebo group (Group 2). We inquired about pre-intervention and post-intervention symptoms in both groups and measured their blood cytokine levels. All statistical analyses were performed using SPSS 23 for Windows. Results: The 80 patients with functional abdominal pain had a mean age of 11.48 +/- 3.86 years. The groups were compared for the severity of symptoms before and after the intervention, and no statistical difference was found (p>0.05). There was no significant difference between the synbiotic group and the placebo group in terms of pre-intervention serum pro-inflammatory or anti-inflammatory cytokine levels (TNF alpha, IFN gamma, IL-10, TGF beta, IL-13), and no statistically significant difference was determined after 8 weeks of synbiotic or placebo administration (p>0.05). A comparison was made of pre-treatment and post-treatment cytokine levels in each group. The most significant finding was the substantial increase in IL-13 levels post-treatment in the synbiotic group (p < 0.001). Conclusion: In the present study, no differences were found between the symbiotic and placebo groups with regard to functional abdominal pain symptoms or serum cytokine levels. However, a significant increase in IL-13 levels was detected after treatment in the symbiotic group. There is a need for further research on the optimal dosage and duration of synbiotic application, the type of probiotic that should be administered, and its effect on cytokine levels in functional gastrointestinal diseases