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Post-mortem plant physiology and soil ecology: decay, transformation, and nutrient cycling after plant death
No full text<p>Plants undergo a series of physiological reactions following their death, characterized by decay and transformation processes. This review article examines plants' cellular and biochemical changes during death and subsequent decomposition. The initial stage of the death process involves the breakdown of cell structure. This breakdown occurs through the activation of enzymes within the cells and the degradation of intracellular components. Intracellular enzymes disrupt the integrity of the cell membrane and initiate reactions leading to cell death. Subsequently, plants become less resistant to external factors, starting the decay process. During decay, plant tissues are influenced by moisture, microorganisms, and other environmental factors. The structural integrity of plant tissues is compromised, and organic matter begins to decompose. This decomposition process allows plants to recycle nutrients back into the environment. During the decomposition process, the biochemical composition of plants also changes. For instance, proteins can be converted into amino acids, carbohydrates into sugars, and fats into acids. These transformations enable the components of plants to be returned to the natural environment. In conclusion, plants exhibit physiological reactions following their death, involving decay and transformation processes of their cellular and biochemical components. These processes facilitate the recycling of nutrients back into the environment and contribute to the natural cycles.</p>
Portfolio of colloidally stable gold-gold sulfide nanoparticles and their use in broad-band photoacoustic imaging
No full text<p>There is an increasing interest in non-invasive photoacoustic imaging and hence demand for non-toxic, stable, optical solid absorbers, particularly in the visible and near-infrared regions enabling deep tissue penetration. The most popular gold nanorods (GNR) suffer from cumbersome synthesis with poor reproducibility and stability under moderate laser exposure. Recently, a new class of nanoparticle, gold-gold sulfide (GGS), was recognized to have strong NIR absorption but lack colloidal stability. Here, we successfully synthesized a portfolio of aqueous GGS nanoparticles (NP) with excellent stability through a one-step, reproducible synthesis: Anionic, cationic, and protein-coated GGS NPs were obtained by using 3-mercaptopropionic acid (3MPA), branched poly(ethyleneimine) (bPEI) and bovine serum albumin (BSA) as a coating. All GGS NPs comprise small (<10 nm) and large anisotropic (>30 nm) morphologies and display two absorption bands centered at 530-540 nm and 800-900 nm. The photoacoustic activity (PA) of GGS NPs in solution at the visible (532 nm) and NIR (800 nm) region is similar and independent of the coating. Remarkably, they outperformed the spherical gold NPs and performed comparable to GNRs. In vitro PA microscopy images recorded with visible and NIR lasers revealed that GGS NPs are successfully internalized by triple-negative MDA-MB-231 breast cancer cells, used for the proof of principle. A coating-dependent intracellular PA signal in favor of GGS-3MPA was observed. The weakest signal was obtained with the GGS-BSA, indicating a low cellular uptake. These stable, aqueous GGS NPs emerge as promising candidates for broad-band PAI and further biomedical applications.</p>
Günümüz Dünyasında Bireyselleşmenin Din ve Aile Kurumu Üzerindeki Etkileri
No full text<p>Değişen dünyada her şey yeni anlamlar kazanmaya çalışırken, insanın en önemli duygularından olan aidiyet hissine ev sahipliği yapan din ve aile kavramları da hayatımızdaki yerini tekrar güncellemektedir. Bireyselleşme ve onun beraberinde getirdiği sancılı süreçler, kitlelerin anlam arayışı ve kolektif bilinci derinden etkilemiştir. Değer yargıları ve toplumsal normlar köklü bir değişimin içine girmiştir. Bu bağlamda makalede tüm bu değişimin ekseninde hayatımıza giren bireyselleşme kavramı, din ve aile kurumu perspektifinden tartışmaya açılarak; geleneksel kimlik ile değişim arasında yoğun gelgitler yaşayan birey ve bireyselleşmenin günümüzde ne gibi sonuçları doğurduğu ele alınacaktır. Dinin sahip olduğu iç dizayn ve amaç bütünlüğü, modernleşme ve hızla değişen teknoloji dünyasında oradan oraya savrulan bireylere sağlam bir dayanak ve ahlaki zemin sağlamaktadır. Günümüzde her geçen gün ivmesi artarak devam eden bireyselleşmeye rağmen aile, sarsılmaz kalesine sığınanları korumaya büyük ölçüde devam etmektedir. Çalışmada din ve ailenin zamana karşı direnişinin modern dünya tarafından pompalanan bencillik ve teknolojik dinamizme rağmen farklı formlarla hayatımızda nasıl özgünleşerek varolduğu değerlendirilmektedir. </p>
Sefalometrik Görüntülerde Ortodontik İskeletsel Sınıflamanın Federe Derin Öğrenme Tabanlı Yöntemlerle Yer İşareti Tespitine Gerek Kalmadan Algılanması (Federated Learning-Based CNN Models for Orthodontic Skeletal Classification and Diagnosis)
No full text<p><strong>Abstract</strong>:</p>
<p>The study aims to evaluate the effectiveness of Federated Convolutional Neural Network (CNN) models for orthodontic skeletal classification using cephalometric images obtained from the ISBI and Dicle datasets. The base DenseNet121 model and its advanced versions, incorporating specific CNN blocks such as “Channel Attention,” “Spatial Attention,” “Squeeze-Excitation,” and “Spatial Pyramid Pooling,” were employed for classification. The models were assessed and compared across Centralized Learning (CL), Local Learning (LL), and Federated Learning (FL) architectures.</p>
<p>The advanced DenseNet121 models demonstrated a significant accuracy improvement of over 24% compared to the baseline model. Notably, the DenseNet121_SA model, enhanced with Spatial Attention, exhibited a remarkable 19% performance increase in the ISBI dataset under the LL architecture. Additionally, the DenseNet121_SA_SE model, augmented with both Spatial Attention and Squeeze-Excitation, achieved an impressive 18% performance gain in the ISBI dataset under LL settings.</p>
<p>Federated CNN models, particularly DenseNet121_SA and DenseNet121_SA_SE, show promising potential in the field of orthodontic skeletal classification. The Dicle dataset, compiled and labeled for this study, will be shared at the end of the project, serving as a valuable resource for AI-based orthodontic dental image analysis. This contribution is expected to facilitate more precise diagnoses over time. The findings also highlight FL’s role in enhancing scalability and data privacy in AI-driven orthodontic research.</p>
<p><strong>Note</strong>: The data for Class_1, Class_2, and Class_3 has been saved in folders named 0, 1, and 2, respectively.</p>
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<p><strong>Öz</strong>:</p>
<p>ISBI ve Dicle veri setlerinden elde edilen sefalometrik görüntüler kullanılarak ortodontik iskelet sınıflandırması için Federe Evrişisimsel Sinir Ağları (ESA) modellerinin etkinliğini değerlendirmek amaçlanmıştır. Temel DenseNet121 modeli ve “Kanal Dikkat”, “Uzamsal Dikkat”, “Sıkma Uyarma” ile “Uzamsal Piramit Havuzlama” gibi belirli ESA bloklarını içeren gelişkin versiyonları sınıflandırma amacıyla kullanılmıştır. Modeller, Merkezi Öğrenme (MÖ), Yerel Öğrenme (YÖ) ve Federe Öğrenme (FÖ) mimarilerde değerlendirilmiş ve karşılaştırılmıştır. Gelişkin DenseNet121 modelleri, temel modelle karşılaştırıldığında %24'ün üzerinde bir değer ile önemli bir doğruluk artışı gözlemlenmiştir. Özellikle, Uzamsal Dikkat ile artırılmış DenseNet121_SA modeli, ISBI veri setinde YÖ mimarisine göre %19 gibi dikkate değer bir performans artışı göstermiştir. Ayrıca, Uzamsal Dikkat ve Sıkma Uyarma ile artırılmış DenseNet121_SA_SE modeli, aynı ISBI veri setinde YÖ ayarlarına göre %18'lik etkileyici bir performans kazancı sergilemiştir. Federe ESA modellerinin, özellikle DenseNet121_SA ve DenseNet121_SA_SE olmak üzere, ortodontik iskelet sınıflandırma alanında umut vadettiği gözlenmiştir. Bu çalışma için derlenen ve etiketlenen Dicle veri setinin proje sonunda paylaşılması, yapay zeka temelli ortodontik diş görüntü analizi çalışmaları açısından önemli bir kaynak olacak ve bu alanda zamanla daha kesin teşhislerin konulmasının önünü açacaktır. Elde edilen bulgular, FÖ’nün ortodonti ile ilgili yapay zeka çalışmalarındaki ölçeklenebilirlik ve veri mahremiyeti konularındaki rolünü de göstermektedir.</p>
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<strong>Not</strong>: Sınıf_1, Sınıf_2, Sınıf_3 verileri sırasıyla 0, 1 ve 2 ismindeki klasörlerde kaydedilmiştir.</p>
The effect of interface enhancement on the mechanical properties of fibre-reinforced PA6 matrix composites in material extrusion-based additive manufacturing
No full text<p>Using different fibres and ratios can considerably enhance the mechanical properties of thermoplastic composites, and the fibre-matrix interface plays a crucial role in realizing the effects of reinforcements. This research aims to enhance the fibre-matrix interface using sustainable resources to increase the mechanical properties of composites produced using additive manufacturing. To do this, cellulose nanofibrils (CNF) were used for surface modification of carbon, glass, and hybrid (carbon + glass) fibres used in reinforcements in the PA6 matrix. Samples were produced by 3D printing done through material extrusion (MEX). and the effects of fibre types and ratios, print layer thickness, and interface enhancement between fibre-matrix on mechanical properties were investigated experimentally. Results reveal a 5 to 11% increase in the tensile strength of the carbon fibre-reinforced samples, whereas a 72 to 88% increase was observed for the glass fibre-reinforced samples. Furthermore, the tensile modulus value has been increased 4 times in carbon fibre reinforcement samples that used modified fibre compared to PA6 pure. Finally, different types and ratios of fibres had an impact on the glass transition temperature, but there was little to no change in the melting and crystallization temperatures. Our work highlights the potential of the proposed CNF modification made to the fibres for MEX production to produce parts with higher mechanical properties.</p>
\title{Development of a 30W SEPIC LED Driver for High and Low Beam Lighting Applications}
No full text<p>In recent years, rapid advancements in LED (Light Emitting Diode) technology have enabled high-brightness white LEDs—with superior features such as energy efficiency and long lifespan—to replace incandescent, halogen, and fluorescent lamps. However, with this transformation, the requirements for high power factor (PF) and low total harmonic distortion (THD) have become prominent to achieve energy savings and reduce environmental impacts. In this paper, the development of low-cost and highly efficient power converter topologies has emerged as a valuable research area. The SEPIC (Single-Ended Primary-Inductor Converter), which offers a single-stage structure, stands out as an ideal solution in non-isolated applications due to its ability to perform both boost and buck operations. Operating the SEPIC topology in discontinuous conduction mode (DCM) allows the input current too closely follow the input voltage, thereby reducing harmonic distortion and enabling a high-power factor. In this study, A 30W SEPIC-based LED driver for automotive lighting systems is designed and implemented, achieving an output voltage of 21V from a wide input voltage range of 9V to 36V. Experimental results show a high efficiency of 91.3% at full load, 94.6% at half load, and up to 95.2% during low-beam dimming operation. This study introduces a robust and efficient reference design for LED drivers supporting high-beam, low-beam, daytime running light (DRL) functions, offering valuable insights for both academic and industrial applications.</p>
Radiation shielding and experimental characteristics of tincal waste added with obsidians
No full text<p>The use of natural resources and waste products represents an effective way of addressing a pressing concern for the future of the global population. It is therefore crucial to evaluate wastes and natural materials as raw materials in many industries. The present study sought to investigate the radiation protection features and experimental characteristics of tincal waste added with obsidians from Eastern Turkey (Nemrut, Pasinler, Sar & imath;kam & imath;& scedil; and Ikizdere regions). Fourier transform infrared spectrometry, X-ray diffraction, Scanning electron microscopy and Energy dispersive spectroscopy were used to have knowledge for morphological and structural properties of the samples. The X-ray diffraction analysis of the samples with higher obsidian content revealed an amorphous structure with a minor presence of crystalline phases. In contrast, the samples with a higher tincal waste content exhibited crystalline phases. Based on morphologic results, it can be said that obsidian samples exhibited relatively smooth and glassy surfaces, whereas tincal waste displayed a rough surface comprising randomly shaped small particles. In addition, radiation attenuating abilities of the tincal waste added with obsidians were determined by the calculation of tenth value layers, half value layers, mean free paths, mass attenuation coefficients, linear attenuation coefficients, fast neutron removal cross sections, effective atomic numbers and buildup factors using the newly produced Phy-X/PSD code. It is obtained that the samples show good radiation protection performances and the samples can be evaluated as better radiation shields for radiation applications especially in construction industry.</p>
Effect of PCE anionic charge density on fly ash cementitious system-PCE compatibility
No full text<p>In this study, the compatibility of polycarboxylate-based water-reducing admixtures (PCEs) with cementitious systems containing fly ash (FA) was investigated. For this purpose, PCEs with carboxylate, phosphate, and sulfonate anionic groups having different anionic charge densities were synthesized. The effects of PCEs on fresh properties and compressive strength of cementitious systems containing FA were investigated. The PCE with 9% phosphate substitution and high anionic charge density was found to be the most effective, requiring the least amount for the target flow. Similarly, in terms of the PCE requirement for the minimum Marsh funnel flow time and rheological parameters, the best performance was obtained with 5% sulfonate substituted PCE having high anionic charge density. While FA had a positive effect on the PCE requirement and consistency retention of the mixtures; it had a negative effect on Marsh funnel flow time, rheological properties, and compressive strength. However, the rheological properties of the mortar mixtures were not adversely affected by the FA substitution as much as that of the paste mixtures. Regarding the 28-day compressive strength of mortar mixtures, the optimum FA substitution ratio was 15%. Fly ash substitution above this level reduced the compressive strength at all ages including 28-day strength. Anionic charge density variation of PCE had no significant influence on the compressive strength of the mortars.</p>
Seafloor nutrient biogeochemistry and benthic fluxes in the Northeastern Mediterranean sea
No full text<p>The coastal ecosystem of the Northeastern (NE) Mediterranean Sea has been affected by nutrient inputs originated from regional rivers and wastewater discharges. Sediment porewater nutrient fluxes into the deep waters are strongly associated with eutrophic and suboxic/anoxic conditions. There was only limited number of studies performed on the porewater and sediment biogeochemistry in the NE Mediterranean Sea having oxic conditions in the deep waters. In this study, therefore, sediment porewater nutrient (Si, N, P) and sediment organic matter biogeochemistry were studied. The study results indicated a series of redox reactions as well as remarkable contribution of porewater diffusive nutrient fluxes to the total nutrient budget in the NE Mediterranean Sea. Lower Si/N and higher N/P molar ratios in the total nutrient inputs are very likely to modify phytoplankton composition and abundance in the phosphorus deficient NE Mediterranean productive shelf waters leading to development of mesotrophic/eutrophic conditions in the NE Mediterranean Sea.</p>
Enzymatic bimetallic Cu-Ni micromotor sensor for xanthine detection
No full text<p>Enzymatic bimetallic Cu-Ni micromotors modified screen-printed electrodes were designed for the determination of xanthine. The bimetallic Cu-Ni micromotors were prepared by electrochemical template deposition. Morphological and structural characterization revealed that the smaller size and active mobility of the particles contribute to a larger specific surface area. The increase in surface area enhances electro-catalytic activities and sensitivity. These improved properties enable the newly created xanthine oxidase-modified Cu-Ni micromotors to function effectively as a high-performance sensor. Designed specifically for detecting xanthine, this sensor boasts high sensitivity, a broad measurement range, low detection limits, and excellent reproducibility and stability. The enzymatic bimetallic micromotor-based sensor was also successfully employed to measure xanthine levels. The limits of detection were determined to be 15.7 nM and 21.53 mu M for xanthine concentration ranges of 0.1 mu M-1 mu M and 10 mu M-300 mu M, respectively, based on electrochemical signals under a magnetic field. Besides, the detection limit was calculated as 9.02 mu M for xanthine concentrations ranging from 0.3 mu M to 20 mu M, based on the speed of the micromotors under a magnetic field (S/N = 3). The impressive results highlight the significant potential of bimetallic Cu-Ni micromotors as sensors, suggesting their promising applications in monitoring food freshness and enhancing security technology.</p>