Aperta Turkish Open Archive
Not a member yet
83692 research outputs found
Sort by
Mercimektepe Höyük: An Overlooked Early Bronze Age Settlement in Central Anatolia
No full text<p>Yozgat possesses numerous untapped historical and archaeological sites awaiting exploration, one of which is Mercimektepe Höyük. One such archaeological site is Mercimektepe Höyük. Listed in the Ministry of Culture and Tourism's register of certified archaeological sites, Mercimektepe Höyük covers an area of approximately 14 acres and is located on the left side of the Yozgat-Sivas Highway, in the Esentepe district. The land has been damaged by years of farming, and the water reservoir built directly on top of it has further exacerbated this damage. Mercimektepe Höyük served as a settlement site at the end of the 3rd millennium BCE and then in the 2nd millennium during the Hittite period. Research has revealed that this site belongs to a culture contemporary with the Alishar culture. This study will provide information about the drilling studies, rescue excavations, and excavation studies conducted on Mercimektepe Höyük to date. This study aims to present the artefacts..." veya "The objective of this study is to document the artefacts found in the excavations at the mound with original photographs, to contribute to the gap in the literature, and to be one of the first studies on the subject.</p>
Fotovoltaik panellerin delaminasyonunda alternatif yöntemlerin denenmesi
No full text<p>Bu tez kapsamında da FV modüllerin geri dönüşümü sürecindeki temel bir proses olan ve günümüz FV geri dönüşüm sürecinin en fazla çevresel yüke sahip olan proseslerinden biri olan delaminasyon prosesi için alternatif bir yöntem geliştirilmeye çalışılmıştır. Bu amaçla c-Si FV modüllerde laminasyon işlemi için genellikle tercih edilen Etilen Vinil Asetat (EVA) kopolimerinin literatürde örneği olmayan bir yöntem olarak biyoteknolojik bir yaklaşımla enzimatik parçalanması ile delaminasyonun gerçekleşmesi için yaklaşımda bulunulmuştur. FV modül delaminasyonunun belirlenmesi adına skor bazlı yeni bir delaminasyon hesaplama tekniği önerilmiştir. Enzimatik delaminasyon sürecin iyileştirilmesi için destekleyici mekanizmalar geliştirilmiştir. Bunlar, termal ve mekanik ön işlem uygulamaları, bilinen bir çözgen olarak tolüen çözgeni desteği ve tolüene alternatif olacağı ve enzimatik aktiviteyi artıracağı düşünülen rafine bitkisel yağ (ayçiçek yağı) uygulamasıdır. Bu çalışma ile tolüenin EVA üzerindeki etkinliği bir kez daha gösterilmiştir. Ayrıca yağ uygulamasının tolüene alternatif bir uygulama olacağı, enzim ile yağ kullanımının delaminasyona ilave fayda sağlayacağı bu çalıma ile ilk kez ortaya konmuştur. Geliştirilen yöntem ile FV'nin tüm katmanları değerli metallere zarar verilmeden %100 oranda ayrılmıştır. Sonuçlar istatistiksel analizler ve karakterizasyon analizleriyle desteklenmiştir. Delaminasyonda yağ ve enzim kullanımının önerilmesi döngüsel ekonomi için yeni bir araştırma sahası sunmaktadır.</p>
HydraViT: Adaptive multi-branch transformer for multi-label disease classification from Chest X-ray images
No full text<p>Chest X-ray is an essential diagnostic tool in the identification of chest diseases given its high sensitivity to pathological abnormalities in the lungs. However, image-driven diagnosis is still challenging due to heterogeneity in size and location of pathology, as well as visual similarities and co-occurrence of separate pathology. Since disease-related regions often occupy a relatively small portion of diagnostic images, classification models based on traditional convolutional neural networks (CNNs) are adversely affected given their locality bias. While CNNs were previously augmented with attention maps or spatial masks to guide focus on potentially critical regions, learning localization guidance under heterogeneity in the spatial distribution of pathology is challenging. To improve multi-label classification performance, here we propose a novel method, HydraViT, that synergistically combines a transformer backbone with a multi-branch output module with learned weighting. The transformer backbone enhances sensitivity to long-range context in X-ray images, while using the self-attention mechanism to adaptively focus on task-critical regions. The multi-branch output module dedicates an independent branch to each disease label to attain robust learning across separate disease classes, along with an aggregated branch across labels to maintain sensitivity to co-occurrence relationships among pathology. Experiments demonstrate that, on average, HydraViT outperforms competing attention- guided methods by 1.9% AUC and 5.3% MAE, region-guided methods by 2.1% AUC and 8.3% MAE, and semantic-guided methods by 2.0% AUC and 6.5% MAE in multi-label classification performance.</p>
Effects of silica nanoparticle addition and PDMS coating on membrane performance and stability in the extraction of aromatic amines
No full text<p>This study investigates novel strategies to improve membrane performance and stability in the extraction of aromatic amines for chiral amine production. The effects of silica nanoparticle addition and polydimethylsiloxane (PDMS) coating were explored, with a focus on the selective extraction of alpha-methylbenzylamine (MBA) and 1-methyl-3-phenylpropylamine (MPPA) from isopropyl amine (IPA). This work introduces a comparative analysis between open and tight membrane extraction (ME) systems, with and without the ionic liquid (IL) [P6,6,6,14][N(Tf)2]. The results reveal that PDMS creates a uniform and dense coating, particularly on PTFE and PVDF supports, while silica nanoparticle coatings were less stable, retaining only 50 % of nanoparticles after ME testing. A PDMS-coated PTFE membrane achieved significantly higher solute fluxes of 1.12 f 0.01, 1.66 f 0.02, and 0.36 f 0.08 g/(m2h) for MBA, MPPA, and IPA, respectively, compared to an IL-wetted PTFE membrane, which was found to have fluxes of 0.60 f 0.06, 1.01 f 0.04, and 0.33 f 0.10 g/(m2h) for the same solutes. A reduction in the pore size of the PTFE support further increased the fluxes to 1.74 f 0.28, 2.75 f 0.25, and 0.45 +/- 0.08 g/(m2h) for MBA, MPPA, and IPA, respectively, achieving selectivity values of 3.83 +/- 0.65 for MBA/IPA and 6.24 +/- 0.88 for MPPA/IPA. Although IL impregnation marginally improved selectivity, it caused a significant reduction in solute fluxes. The PDMS coating retained 92.1 % of its mass after 24 h, while the IL retained 87.2 % over the same period. Compared to the tested IL, which presents safety concerns due to its flammability and corrosiveness, PDMS coatings provide a safer and more environmentally friendly alternative, as PDMS is non-toxic and does not bioaccumulate. These findings underscore the superior performance and environmental benefits of novel PDMS-coated membranes in tight ME setups compared to IL-based open ME systems.</p>
On Certain Fourth-Order Linear Recursive Sequences
No full text<p>In this paper, we introduce a fourth-order linear recursive sequence that is related to the concept of subbalancing numbers. This sequence is constructed by using the third balancing number in the Diophantine equation of subbalancing numbers and is called the sequence of -Lucas subbalancing numbers. Motivated by the results for -Lucas subbalancing numbers, we obtain several algebraic identities regarding -Lucas subbalancing numbers. Furthermore, we derive some algebraic relations between -Lucas subbalancing numbers and some other integer sequences</p>
Arthrospira platensis in Family Medicine
No full text<p>Arthrospira platensis (commonly known as Spirulina) has emerged as a prominent microalga <br>
with significant therapeutic and nutritional potential. This review investigates the role and applications of <br>
A. platensis within family medicine by exploring its nutrient composition, health benefits, clinical <br>
evidence, and implications for preventive healthcare. A systematic review methodology was utilized, <br>
drawing from databases including PubMed, ScienceDirect, and Scopus, with inclusion criteria <br>
emphasizing peer-reviewed articles from the past ten years. The principal findings indicate substantial <br>
antioxidant, anti-inflammatory, and immunomodulatory effects, highlighting the microalga's potential as <br>
a supportive therapeutic agent in managing chronic diseases such as metabolic syndrome, cardiovascular <br>
diseases, diabetes mellitus type 2, and inflammation-related disorders. Challenges related to <br>
standardization, clinical validation, and regulatory considerations are identified as critical areas for future <br>
research. Ultimately, integrating A. platensis into family medicine practice could enhance patient<br>
centered care through preventive and complementary health strategies.</p>
A facile adsorbent using graphitic carbon nitride with silver and nickel (Ag/ Ni@g-C<sub>3</sub>N<sub>4</sub> nanocomposites) for Pb(II) extraction
No full text<p>Graphitic carbon nitride (g-C3N4) embedded with silver (Ag) and nickel (Ni), forms Ag/Ni@g-C3N4 nanocomposites, and has been explored as a novel adsorbent in the dispersive solid phase microextraction (DSPME) for Pb(II) determination, utilizing flame atomic absorption spectroscopy (FAAS) technique. The synthesized nanocomposites were analyzed using different characterization techniques including; X-ray diffraction (XRD), scanning electron microscope coupled with energy dispersive x-ray (SEM-EDX), and Fourier-transform infrared spectroscopy (FTIR). To optimize the extraction process, several analytical parameters were adjusted such as: pH, used adsorbent quantity, adsorption/elution time, sample volume, eluent volume, and amount of elution solvent as 8, 5 mg, 60 sec /30 sec, 30 mL/ 2.5 mL, and 0.5 mol/L HNO3, respectively, based on the recoveries of Pb(II). Matrix effects were also examined to ensure the accuracy of the method. The method's limit of detection (LOD) was 0.270 mu g/L, the limit of quantification (LOQ) was 0.91 mu g/L, and the preconcentration factor (PF) was 12. The percent relative standard deviation (%RSD) was below 10 %, and the coefficient of determination (R2) was 0.9952, indicating good precision and linearity. The accuracy of the method was confirmed by analyzing certified reference materials (CRMs). The concentration of Pb(II) in various dietary samples, and tap and industrial wastewater samples were determined by using the presented microextraction procedure.</p>
Low-Grade Chromite Beneficiation Through Spiral Concentration: A Review from the Turkish Market Perspective
No full text<p>Chromite production is required for numerous industrial applications worldwide, with Turkey emerging as a major supplier of chromite ore. The decreasing grade of chromium-ore bodies and difficulties in identifying new high-grade deposits highlight the significance of processing fine, low-grade ores. This review assesses all chromite beneficiation methods, along with a detailed examination of spiral concentrators, which is used as a conventional method for chromite processing. The significance of processing low-grade and fine chromite is discussed, and advancements in separation methods are observed. The chromium market has been outlined from an economic perspective, maintaining Turkey as its focal point.</p>
Selective and sensitive detection of glutathione with a novel fluorescein-based probe in fully aqueous media and its application in food samples
No full text<p>We devised a novel fluorescent probe, FL-T, bearing fluorescein and thienyl acrylic acid moiety, which was designed and synthesised to detect glutathione (GSH). Utilising micelle-catalysed cyclisation/elimination reaction, FL-T demonstrated exceptional sensitivity and operability in a fully aqueous solution, with a low limit of detection (LOD = 41.2 nM), and superior selectivity over cysteine (Cys), homocysteine (Hcy), H2S and other analytes. Furthermore, FL-T successfully detected GSH in fruit and vegetable samples. These findings suggest that FL-T is a promising tool for detecting GSH in various environments.</p>
Genome-wide association of gene regions controlling selenium and magnesium accumulation in walnuts (Juglans regia L.)
No full text<p>Walnut (<em>Juglans regia </em>L.) is one of the most economically important species. It is of great importance to the food industry due to its nutritional value, and high content of many beneficial components such as macro and microelements. In the current study, the aim was to determine markers of single nucleotide polymorphism (SNP) associated with the gene(s) controlling the accumulation of Selenium (Se) and Magnesium (Mg) in walnuts. Se and Mg concentrations were measured in 154 genotypes of <em>Juglans regia </em>in 2021 and 2022. A total of 16,473 SNP markers were used for association mapping to analyze the marker-trait associations. The Se and Mg concentrations exhibited a normal distribution pattern with high heritability values (0.96 for Se and 0.98 for Mg) for the two years. Association mapping analysis was carried out with TASSEL software (v5.2.87) using the mixed linear model method. The result was that 17 markers for Se and 15 markers for Mg were significantly associated. A total of 189 and 86 putative candidate genes were detected for markers significantly associated with the Se and Mg levels, respectively. Among these genes, 33 genes are involved in ion binding, one gene in the binding and transport of Mg ions, 10 in hormone metabolism, and 53 in DNA and RNA binding. These potential candidate genes and markers observed in this study can be used in marker-assisted breeding programs to improve biofortified walnut varieties and further explore the genetic mechanisms underlying the Se and Mg accumulation.</p>