Challenge Journal Publications (TULPAR Academic Publishing)
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Structural behavior of historical Obruk Inn under different earthquakes
Full text linkMasonry structures is one of the most preferred structure types throughout history. The advantageous of these structures can be categorized as longevity, affordability and easy access to materials. Due to a lack of information and constructive errors, masonry structures suffer major damage under effect of earthquakes. While the vertical load carrying capacity of a masonry structure is excellent, its performance under horizontal loads is very poor. The brittle behavior of masonry structures, in particular, causes the structure to suffer significant damage or collapse completely during an earthquake. Türkiye is situated over a major earthquake zone. Throughout history, there has been numerous major earthquakes. These earthquakes have demolished the masonry structures resulted in significant life and economic losses. Therefore, in recent days, the examination of the seismic resilience performance of masonry structures as well as the required strengthening have become a pivotal issue. Thus, the aim of this study is to analyze the seismic performance of historical Obruk Inn subjected to different earthquake effects via finite elements method (FEM). To do this, the plans obtained from on-site inspections for historical Obruk Inn to create structural FEM model and its performance was evaluated under the influence of various earthquake excitations. As a result of the analyses, it was determined that the historical Obruk Inn structure should have immediate be strengthened against a possible earthquake
Analyzing the educational quality of YouTube videos on paravertebral block techniques
Full text linkAim: People can learn new skills, explore content related to their interests, and get to know different cultures through YouTube videos. It is important to be conscious when using platforms such as YouTube and to take care to obtain information from verified and reliable sources. Students especially watch medical videos on YouTube, which can improve their medical knowledge. Our aim in this study is to evaluate the educational content and quality of paravertebral block videos on YouTube.Materials and Method: Videos were recorded by typing the term 'paravertebral block ultrasound' into the YouTube search engine. In filtering, sorting was done according to the number of views. 100 videos on the first 5 pages were watched and evaluated. To evaluate the videos on YouTube, we used two different surveys, evaluating the educational content of the videos (Survey 1) and evaluating the quality of the videos (Survey 2).Results: Our study revealed that only a third of paravertebral block education videos met relevant criteria, with just (33) 18.2% demonstrating both good educational quality and preparation. There was a positive correlation between the video educational quality score and all parameters, with significant differences found for “video duration” and “video preparation quality score” (r=0.506, p=0.003, and r=0.84, p<0.001, respectively). Similarly, the video preparation quality score showed a positive correlation with all parameters, with significant differences found for “number of video likes” and “video duration” (r=0.373, p=0.033, and r=0.413, p=0.017, respectively).Conclusions: Paravertebral block videos on YouTube are inadequate in terms of educational and preparation quality. According to our analysis, we do not recommend using YouTube videos for educational purposes
The novelty design method in lightweight structures with low effective elastic modulus
Full text linkLightweight structures are of great interest in industrial areas such as automotive, aerospace, and biomedical due to their lightness, and superior mechanical performance. The advantages of lightweight structures are increased with the spread of additive manufacturing and design them in various geometries. Beam-based structures and triply periodic minimal surface structures are currently used to extend these advantages. In this study, it is aimed to create die models of beam-based structures in order to contribute to the geometric diversity for lightweight structures. By designing the die lattice structures of the beam-based structures, the comparison of the mechanical performance of basic lattice and die lattice structures with the same porosity was carried out. For FCC, CFCC, and Octet-Truss lattice structures, basic lattice and die lattice structures are designed on scaffolds in 5x5x5 array with 50%, 60%, 70%, and 80% porosity. Numerical data were obtained for Ti6Al4V with compression tests simulated by applying pressure in the -y direction. According to numerical analyses, the effective elastic modulus decreased due to the increased porosity in both structure models. The CFCC and Octet Truss scaffolds have different force transmission performances. Likewise, this situation is observed in die lattice structures, but the force transmission with the surfaces reveals the difference of the structures. The effective elastic modulus of basic lattice structure with 80% porosity of the Octet Truss structure is approximately twice that of the die lattice structure. Thus, the use of die lattice structures will provide advantages for the design of lightweight structures with low elastic modulus
A comprehensive retrospective analysis of interfascial plane blocks and peripheral nerve blocks at a tertiary research hospital: Single center experience
Full text linkAim: This study aimed to analyze regional anesthesia practices at a tertiary research hospital as a single center during a one-year period (January 2022 to January 2023).Materials: Data on over 2,000 nerve blocks were retrospectively reviewed, including: type of nerve block performed (peripheral nerve vs. fascial plane, location of block (upper vs. lower extremity), purpose of block (anesthesia or analgesia) and outcomes.Method: Data was analyzed to assess trends in block utilization, identify preferred block types and locations, and compare the use of peripheral nerve blocks versus fascial plane blocks for anesthesia and analgesia. Additionally, the potential opioid-sparing benefits of fascial plane blocks were evaluated.Results: The analysis revealed a notable shift towards fascial plane blocks (61%) compared to peripheral nerve blocks (39%). Lower extremity blocks were more common (56%), with sciatic, saphenous, and femoral nerve blocks being the most frequently used. In the upper extremity (44%), infraclavicular and interscalene brachial plexus blocks dominated. Interestingly, fascial plane blocks were primarily employed for analgesia, while peripheral nerve blocks served both anesthetic and analgesic purposes. The study identified opioid-sparing advantages associated with fascial plane blocks, highlighting their potential role in multimodal pain management strategies.Conclusions: Based on these findings, areas for improvement in regional anesthesia practices were identified. Educational programs will be adjusted accordingly. Future research will delve deeper into patient characteristics, block selection rationale, and incorporate patient-reported outcomes alongside opioid consumption and pain scores. This study serves as a foundation for future enhancements in regional anesthesia practices, aiming to optimize patient care and outcomes
Effect of soil types on nonlinear earthquake behavior of buildings
Full text linkThe Winkler method, which is widely used today, assumes that the soil behaves elastically and does not take into account the soil shear stress values, it is insufficient to reflect the actual soil behavior. Especially in the earthquake calculations of rigid and massive structures such as high-rise buildings, dams, suspension bridges, viaducts, it is necessary to consider soil as a dynamic system that changes shape and affects the behavior of the structure in terms of inertia. In response to the effect of soil on the structure, the structure also affects soil both kinematically and dynamically. Thus, in the absence of the structure, the earthquake data, which is only a result of the dynamic behavior of the soil in its internal structure, now acquires a more complex soil motion characteristic that is also affected by the presence of the structure. The observations made in some earthquakes show that the changes between the records taken simultaneously on the building foundation and at soil surface not a point far from foundation, show that the structure also affects soil therefore soil motion in response to the effect of the earthquake on the structure. In this study, the effect of soil types on the nonlinear seismic behavior of reinforced concrete structures was investigated. For this purpose, 7-storey building models with different plans and rigidities were created. The behavior of these models under 11 different earthquake loads for the ZA, ZB, ZC, ZD, ZE soil types specified in the Turkish Building Earthquake Code has been investigated. Analyzes were made using the time history method with the help of the SAP2000 program. As a result of the analysis, the displacements, plastic hinge formation, Effective inter-storey drift and period values obtained for different models were compared
Predicting compressive strength of AAC blocks through machine learning advancements
Full text linkDetermining the strength properties of Autoclaved Aerated Concrete (AAC) through conventional compression experiments is both time-consuming and costly. Using sophisticated Machine Learning (ML) algorithms to forecast concrete compressive strength can expedite time-consuming experimental procedures and reduce expenses. In this study, four ML models were proposed, including Random Forest (RF), Support Vector Regression (SVR), Linear Regression (LR), and Stochastic Gradient Descent (SGD). These models were developed to forecast the compressive strength of AAC blocks based on a dataset of 525 cubic samples. By comparing the results using different evaluation indices, the study analyzed each input variable’s relative importance and impact on the output. The findings revealed that the SVR model had the least error and is thus the most suitable for concrete compressive strength estimation. This approach results in cost savings on both specimens and laboratory tests. Out of the seven input factors, which encompass the proportions of water, cement, sand, lime, fly ash, aluminum powder, and gypsum, the proportions of cement and water content were pinpointed as the most crucial characteristics. In contrast, aluminum powder and gypsum displayed less prominent significance
Impact of iron powder and blast furnace slag on the mechanical properties of polymer concrete: An experimental and hyperparameter-tuned ANN-based study
Full text linkPolymer-based materials have become increasingly used in concrete production and various engineering applications due to their versatile properties. In particular, polymer concrete (PC) has become a preferred reinforcement material in the construction industry. Various studies have been carried out to evaluate the performance of PC and to improve its mechanical properties by adding different admixtures. This study investigates the effects of fine materials such as iron powder (IP) and blast furnace slag (BFS) on the mechanical performance of PC. Within the scope of the study, samples with 5% and 10% IP, 5% and 10% BFS, 2.5% IP + 2.5% BFS and 5% IP + 5% BFS were prepared. These specimens were cured in the same laboratory environment and subjected to mechanical tests at the end of the 7th day. The results of the mechanical tests were compared to reveal the effect of fine materials on the performance of the PC. The potential of an artificial neural network (ANN) model is investigated to replicate real-world outcomes. The findings provide valuable insights into the potential of iron powder and blast furnace slag as admixtures to improve the mechanical properties of PC
Determining datum temperature and apparent activation energy: an approach for mineral admixtures incorporated cementitious systems
Full text linkThe maturity method is used to predict the strength of concrete by monitoring its temperature history. Accuracy of maturity method relies on the dependable determination of the datum temperature and the apparent activation energy. The current study introduces a new approach, complementing those in ASTM C1074-11, for determining the datum temperature and apparent activation energy. The experimental study involved using two different mineral additives to portland cement at 6%, 20%, and 35% replacement amounts. The mortars were then cured at temperatures of 5, 20, and 40 °C, and their strengths were determined. Subsequently, the datum temperatures and apparent activation energies for these mixtures were calculated using both the proposed approach and the alternatives from ASTM C1074-11. Strength estimations were conducted in conjunction with commonly used maturity functions. The results indicate that the proposed approach determines the datum temperature and apparent activation energy reliably for mineral admixture-incorporated mortars. Furthermore, the predicted strengths, derived from the datum temperature and apparent activation energy calculated through the proposed approach, show a closer alignment with the experimental results when applying the Nurse-Saul and Hansen-Pedersen equations, as opposed to the Rastrup and Weaver-Sadgrove models
The effect of modified paramedian and median approaches of spinal anesthesia on postspinal acute low back pain in patients undergoing urological surgery: a prospective cohort study
Full text linkBackground: Low back pain after spinal anesthesia may be a complicated issue for many patients. We aimed to evaluate the incidence of postspinal low back pain in the modified paramedian approach of spinal anesthesia compared to the classical median approach.Materials and Method: The study is a prospective non-randomized observational trial. We included 297 patients aged 20 to 80 years who underwent urological surgery under spinal anesthesia. Patients were allocated into two groups: In Group P, patients underwent spinal anesthesia by using a modified paramedian approach and in Group M, the classical median approach was used. Primary outcome was the incidence of postoperative low back pain. Secondary outcomes were number of needle insertion attempts, needle bone contacts and patient satisfaction.Results: The incidence of low back pain in Group M was 70.3% on the first day, 39.5% on the 7th day and 5.9% at the end of one month after surgery. In Group P, the incidence of low back pain was 30.7% on the first day, 12.4% on the 7th day and 0.7% at the end of one month after surgery. The low back pain scores were significantly lower in group P at all-time points. Patient satisfaction was significantly higher in group P (p=0.038). The number of needle interventions (p=0.001) and bone contact (p=0.000) were significantly lower in group P.Conclusions: Low back pain was less common with the modified paramedian approach compared to the classical median spinal approach. We found lower number of needle insertion attempts and bone contacts in the modified paramedian technique. Patient satisfaction was also higher in the paramedian technique