Analyzing the Relationship Between the Formation of Sinkholes and Structural Deformation: a Parametric Study

In Turkey sinkhole formations have been observed in recent years, the number of which has increased over time. These sinkholes have started to cause damage to infrastructure and superstructures, especially in rural areas. In this study, considering the rapidly increasing number of sinkholes, first of all, the sinkhole formation mechanism of the region and the characteristics of the sinkhole were examined. Then, an analysis was made on the superstructure inventory of the region. According to the investigations, a numerical study was carried out considering the general characteristics of the sinkholes and the building stock. With this study, three different heights of buildings representing the building stock of the rural area were selected and thus the pressure (S) exerted by the buildings on the ground became a main parameter. In addition to these, a total of 81 finite element models with three different sinkhole widths (D) and four different sinkhole depths (L) selected at four different distances (A) from these structures were created with the finite element program. The structure and sinkhole interaction parameters obtained from the quite comprehensive data set were evaluated in the context of settlements that may occur in the structure. While creating the model, the geotechnical properties of the soil of the region were taken within the scope of the sinkhole formation mechanism. As a result of the analyses, it was observed that the depth of the sinkhole (L), the diameter of the sinkhole (D) and the distance between the sinkhole and structure (A) had a direct effect on the sinkhole-structure interaction, and the structure load had a limited effect. The results also have indicated that the sinkholestructure interaction is limited in the sinkholes formed in diameter and high distance.The authors would like to thank the Konya Technical University Sinkhole Application Research Centre and also Disaster and Emergency Management Presidency (AFAD) for their supporting.Konya Technical University Sinkhole Application Research Centre; Disaster and Emergency Management Presidency (AFAD

Investigation of the Strength of Reinforced Masonry Walls Under the Effect of Earthquake Using Geogrid

In this study, the investigation focuses on enhancing the structural integrity of brick wall samples by incorporating geogrid materials of varying strengths. The collapse and shear strengths under horizontal loads were examined in planes, and the results were compared. A comparative analysis has been conducted to evaluate the use of both uniaxial and biaxial geogrid as confinement reinforcement on the surfaces of brick masonry specimens. To draw a comparison, unreinforced masonry walls, masonry walls completely reinforced with uniaxial geogrid material, and masonry wall samples fully reinforced with biaxial geogrid material were created. Moreover, 12 experiments have been carried out, in which the standard slip stress experiment technique recommended by ASTM 1391-81 for masonry wall samples was used. The observed behaviors in the experimental samples including formed cracks, horizontal load-displacement graphs, and energy absorption capacities were compared. The achieved result showed that the masonry wall reinforced with biaxial geogrid material showed a 10% higher load capacity than the unreinforced masonry wall

An Example of Intracontinental Cross Faults Formation From the Vicinity of Karapınar (Konya - Central Anatolia)

Karap ; imath;nar (Konya, Turkey) is located in the central part of the Anatolian micro-plate which is characterized by differently oriented Neogene-Quaternary horst - graben structures. The basement of the region is composed of Mesozoic-Paleogene rocks. In the various Neogene basins, Miocene-Pliocene sedimentary and volcanic rocks overlie the basement rocks and form the secondary rock units. The youngest units are Plio-Quaternary aged terrestrial sediments and volcanics. The main structure of the study area consists of WNW-ESE and NE-SW trending intersecting graben-horst structures and the normal faults forming them. The approximately WNW- ESE trending basins are filled with Miocene-Pliocene sediments, while the NE-SW trending basins are filled with Pliocene-Quaternary sediments. Kinematic studies show that the faults in the study area are developed in all directions and the distribution of the slicken lines indicates that there is multidirectional crustal extension. The principal stress axes obtained from all the kinematic data show that sigma 1 is nearly vertical, sigma 2 and sigma 3 are horizontal. If all faults are assumed to have been formed due to the same stress system, the study area is predominantly elongated in the NW-SE direction. However, detailed field observations and structural analyses indicate that the NE-SW trending fault systems are younger than the WNW-ESE trending faults. This indicates that firstly NNE-SSW and then NW-SE crustal extension developed in the study area respectively.Konya Provincial Directorate of Disaster and Emergency (AFAD) [2020K14-138637-2]The authors are grateful to the anonymous reviewers for their constructive criticism and suggestions that helped to im-prove the manuscript significantly. This research was partly supported by the Konya Provincial Directorate of Disaster and Emergency (AFAD) within the scope of the "Detection of the Sinkhole Around Karap ; imath;nar" Project (No: 2020K14-138637-2)

Development and Mechanical Characterization of a Waste Polyamide-Reinforced Polymer Matrix Composite

Bu çalışmada, fabrika atığı olan poliamid ipliklerin katkısıyla çevre dostu ve ekonomik açıdan avantajlı yeni bir polimer matris kompoziti geliştirilmiş ve bu kompozitin mekanik özellikleri kapsamlı bir şekilde incelenmiştir. Araştırmanın ana hedefi, atık malzemelerin değerlendirilmesi yoluyla sürdürülebilirlik ve maliyet etkinliği sağlarken üstün performanslı malzemeler üretmektir. Reçine kompozitinin mekanik performansını belirlemek için çekme testi, üç noktadan eğilme testi ve sıyrılma testi gibi temel mekanik testler gerçekleştirilmiştir. Bu testler, eğilmede mukavemet, eğilmede elastiklik modülü, birim şekil değiştirme ve gerilme performansı gibi kritik parametreleri değerlendirmek için yapılmıştır. Çalışmada, farklı boyutlardaki poliamid ipliklerin kompozit malzeme üzerindeki etkileri araştırılmıştır. Analizler, deneysel parametrelerin malzemenin mekanik performansı üzerindeki etkilerini detaylı bir şekilde ortaya koymuştur. Sonuçlar, atık poliamid katkısının polimer matris kompozitin mekanik özelliklerine anlamlı katkılar sağladığını ve optimize edilmiş formülasyonların endüstriyel uygulamalar için güçlü adaylar olduğunu göstermiştir.In this study, a novel, eco-friendly, and cost-effective polymer matrix composite was developed by incorporating waste polyamide yarns derived from industrial processes. The mechanical properties of this composite were comprehensively investigated. The primary objective of the research is to promote sustainability and cost efficiency through the utilization of waste materials while producing high-performance materials. To evaluate the mechanical performance of the resin composite, fundamental mechanical tests such as tensile testing, three-point bending tests, and delamination (interfacial) testing were conducted. These tests were performed to assess critical parameters including flexural strength, flexural modulus, strain at break, and stress performance. The study also examined the effects of polyamide yarns with varying dimensions on the composite material. The analyses revealed detailed insights into how experimental parameters influence the mechanical behavior of the material. The results demonstrated that the incorporation of waste polyamide significantly enhances the mechanical properties of the polymer matrix composite and that optimized formulations hold strong potential for industrial applications

Characterization of Fly Ash Reinforced Wood Polypropylene Composites

In this study, fly ash, which is released as waste from thermal power plants and has negative effects on the environment, was evaluated as a filler in wood-plastic composite materials (WPC). For this purpose, inorganic fly ash from thermal power plants was mixed with polypropylene (PP) thermoplastic polymer at 10%, 20%, 30%, 40%, and 50% by extrusion method instead of wood flour used in wood plastic composite materials. Maleic anhydride-treated polypropylene (MAPP) was used to strengthen the bonding during WPC production. The material mixed in extrusion was passed through a crusher and turned into pellets. Test samples were prepared using injection molding of pelletized WPC material. Density, thickness swelling, water absorption, modulus of rupture, impact strength, modulus of elasticity in bending, tensile strength, janka hardness, differential scanning calorimetry (DSC), and thermogravimetric analyses (TGA) were performed on the prepared test samples. The results indicated that as the amount of fly ash used in the wood-plastic composite material increases, the density increases but the thermal degradation temperature of the material, water uptake, the swelling ratio to its thickness, tensile strength, impact strength, janka hardness, modulus of rupture, and modulus of elasticity decrease. © The Author(s) 2024.Istanbul Üniversitesi; Düzce Üniversitesi, (2020.07.01.1079); Düzce Üniversites

Sinkhole detection via deep learning using DEM images

Sinkholes, commonly observed in karstic regions, are landforms with unpredictable formation time and location. These landforms are an important natural disaster that threaten human life and country economies. Sinkholes, observed as cover collapse or depressions in nature, may be easily identified with remote sensing methods (digital elevation models, satellite and aerial photographs, etc.). These methods reduce time and labor burdens before field investigations. In this study, the aim was to accurately identify sinkholes by training a deep learning method with hillshade images obtained from DEM data. In line with this aim, the study area was identified as the Karapınar region (Konya, Türkiye), where many sinkholes have formed in recent periods linked to climatological and anthropological factors. In this study, 5 different (nano, small, medium, large and x-large) sinkhole detection models were developed using YOLO v8. The developed models provided high success rates in detecting sinkholes with different diameters and depths. © The Author(s) 2025.Türkiye Bilimsel ve Teknolojik Araştırma Kurumu, TÜBİTA

High-Performance Uv–vis–nir Photodetectors Based on Pedot Obtained by Plasma-Enhanced Chemical Vapor Deposition

This study presents the fabrication of organic UV–vis–NIR photodetectors based on poly(3,4-ethylenedioxythiophene) (PEDOT) thin films synthesized via a plasma-enhanced chemical vapor deposition at 10, 20, and 30 W plasma power. The effects of plasma power on polymerization, as well as optical, structural, morphological, and optoelectronic properties, are analyzed using UV–vis, Fourier transform infrared spectroscopy, scanning electron microscope, and scanning electron microscopy–energy-dispersive X-ray. The films, exhibiting a bandgap of 3.52–3.59 eV, are uniformly coated on Si surfaces. Photodiode and photodetector performance is evaluated through current–voltage and current–transient measurements under varying light intensities and wavelengths. PEDOT films synthesized at 10 W exhibit superior photodetector performance, with maximum responsivity and detectivity of 0.0975 A W−1 and 1.65 × 1010 cm Hz0.5 W−1 at 900 nm, and a noise-equivalent power of 5.38 × 10−12 W Hz−1/2. Maximum external quantum efficiency is recorded as 23.975% at 450 nm. These results emphasize the suitability of low-power PEDOT films for optoelectronic applications due to their superior morphology and optoelectronic characteristics. © 2025 Wiley-VCH GmbH

Cutting Force and Delamination Optimization of Nanoparticle-Reinforced Basalt/Epoxy Multi-Scale Composites in Dry Drilling by Taguchi Design

PurposeThe real-time performance requirements of montage components and assembly features of structural parts are among the most critical factors for the utilization of polymer-matrix laminates in the aerospace industry. In this context, the present study provides a comprehensive perspective on the dry drilling optimization of nanographene-added basalt fiber-reinforced epoxy composite laminates, focusing on cutting force and surface delamination damage.Design/methodology/approachThe combined effects of feed rate (FR) (0.10, 0.15 and 0.20 mm/rev), tool diameter (3 and 5 mm) and nanographene ratio (0, 0.3 and 0.7 wt.%) were investigated as input parameters using a specially designed dagger tool for the first time in the literature. Additionally, Taguchi's L18 design was employed to determine the optimal combination of input variables.FindingsThe results indicate that lower feed rates, smaller tool diameters and higher nanoparticle concentrations result in the lowest cutting forces. As for the delamination factor, lower feed rates, larger tool diameters and higher nanoparticle concentrations were identified as the best combination to maintain the structural integrity of the machined surfaces. Only localized minor chips were seen at the best combination. Detected outcomes can be used for future projects that aim to explore the joining strength of mechanical assembly for aircraft laminate structures.Originality/valueAchieving high-performance composite assemblies in aerospace applications (particularly in wing, fuselage and interior components), with sufficient mechanical properties, requires precise optimization of drilling operations to ensure strong joints and high-quality surfaces without delamination defects. This study, specifically focusing on nanoparticle-modified basalt fiber-reinforced laminates for aerospace implementations, is the first to elucidate the combined effects of FR, tool diameter and nanoparticle ratio on thrust force and delamination factor

Investigation and Efficiency Analysis of Dual-Boost Bridgeless PFC Converter

Artan enerji tüketimi ile birlikte elektrik sistemlerinde verimlilik günden güne daha da önemli hale gelmektedir. Bu durum doğrultuculardan kaynaklanan güç kalitesi sorunlarına çözüm sunan Güç Faktörü Düzeltmeli dönüştürücülerde yüksek verim arayışını zorunlu kılmıştır. Bu çalışmada yüksek verim sunan Köprüsüz Boost PFC Dönüştürücüler incelenmiştir. Bu dönüştürücülerin olumlu ve olumsuz özellikleri sunulmuştur. Köprüsüz dönüştürücülerin bir türü olan Dual-Boost Köprüsüz PFC Dönüştürücü tanıtılmış ve dönüştürücünün PSIM ortamında simülasyonu yapılmıştır. Elde edilen giriş akımı harmonik içeriği, güç faktörü ve verimlilik değerleri, daha önceki çalışmalarımızda aynı parametrelerle tasarlanan Klasik Boost PFC Dönüştürücü ile karşılaştırılmıştır. Dual-Boost Köprüsüz PFC Dönüştürücü farklı güç seviyelerinde çalıştırılarak güç faktörünün ve toplam harmonik bozulmanın değişimi grafiksel olarak sunulmuştur. Daha detaylı bir verim analizi için dönüştürücüler farklı iletim dirençlerine sahip MOSFET'ler kullanılarak tekrar çalıştırılmıştır. Sonuç olarak Köprüsüz PFC Dönüştürücülerin verimlilik avantajı kanıtlanmıştır. Ayrıca SiC gibi düşük iletim direncine sahip MOSFET'lerin bu dönüştürücüler için önemi anlaşılmıştır

Hybridcisn: Integrating 2d/3d Convolutions and Involutions With Hyperspectral Imaging and Blood Biomarkers for Neonatal Disease Detection

Cihan, Mucahit/0000-0002-1426-319XEarly detection and accurate diagnosis of neonatal diseases are crucial for improving health outcomes and reducing infant mortality. This study introduces a novel Hybrid Convolutional and Involutional Spectral Network (HybridCISN) that integrates hyperspectral imaging (HSI) data with blood biomarker analysis to enhance neonatal health diagnostics. By combining 2D convolution, 3D convolution, and involution layers, the HybridCISN model extracts spatial, spectral, and channel-specific features, addressing limitations in traditional diagnostic methods. The model was evaluated through two distinct approaches: (1) using only HSI spectral data and (2) integrating HSI spectral data with blood biomarkers such as haemoglobin and bilirubin levels. These approaches were tested for both binary classification (healthy vs. unhealthy neonates) and multiclass classification (specific neonatal diseases such as intracranial hemorrhage, necrotizing enterocolitis, pneumothorax, and respiratory distress syndrome). Experimental results demonstrate the HybridCISN model's superior performance, achieving an overall accuracy of 93.64% for binary classification and 90.25% for multiclass classification. Compared to state-of-the-art methods such as the involution-based HarmonyNet and the 2D/3D convolution-based HybridSN, the HybridCISN model achieved accuracy improvements of 0.8% and 1.5%, respectively, in multiclass classification. The second approach, integrating blood biomarkers, improved diagnostic sensitivity and specificity, emphasizing the value of multimodal data fusion. Involution layers reduced channel redundancy and optimized feature extraction, as confirmed by ablation studies. The HybridCISN model offers a scalable and non-invasive diagnostic framework, addressing clinical applicability and biomarker accessibility, while combining precision, efficiency, and robustness to advance neonatal disease detection and set a benchmark for future research in medical imaging.This study was supported by the Scientific and Technological Research Council of Turkey (TUBITAK) under the Grant Number 122E021. The authors thank TUBITAK for its support. We sincerely appreciate Prof. Dr. Hanifi Soylu and Assoc. Prof. Dr. Murat Konak for their valuable contributions and guidance throughout the research process. Their expertise and support were instrumental in the successful completion of this project.Scientific and Technological Research Council of Turkey (TUBITAK) [122E021]; TUBITA