Browsing by Publisher "Elsevier"
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- ItemA novel hybrid MCDM framework combining TOPSIS, PROMETHEE II, and VIKOR for peach drying method selection(Elsevier, 2024-11) Gülmez, Burak; 222298The selection of optimal drying technologies for peach processing presents a complex decision-making challenge due to multiple conflicting criteria. This study introduces a novel hybrid multi-criteria decision-making (MCDM) framework combining TOPSIS, VIKOR, and PROMETHEE II methods to evaluate eight drying technologies. The evaluation was conducted across twelve criteria, encompassing product quality, operational efficiency, economic factors, and environmental impact. Data were collected from five industry experts through structured matrices. The results demonstrate that vacuum drying emerged as the optimal technology, maintaining the top position in 75 % of sensitivity scenarios. Freeze drying and heat pump drying consistently ranked among the top three alternatives across all methods. The correlation analysis revealed strong agreement between VIKOR and PROMETHEE II rankings (0.857), while TOPSIS provided complementary insights. Sensitivity analysis identified energy consumption, investment cost, and nutritional retention as the most critical factors influencing technology selection. The findings indicate that advanced drying technologies significantly outperform traditional methods in terms of overall performance. This research provides a comprehensive framework for evidence-based decision-making in food processing technology selection and establishes quantitative benchmarks for future technology evaluations in the fruit drying industry.
- ItemDams in the wake-up call of the 2023 Türkiye earthquake sequence: Insights from observed damages, risk assessment, and monitoring(Elsevier, 2024-01) Hariri-Ardebili, Mohammad Amin; Tosun, HasanOn February 6, 2023, Türkiye experienced a significant earthquake with a magnitude of 𝑀𝑤 7.81, followed by four additional earthquakes throughout the day, measuring 𝑀𝑤 5.8 and above, including one with a 𝑀𝑤 7.5. As a result, over 100 dams in the region experienced low to high seismic loads. The impact of these seismic events resulted in a range of damages to dams, varying from light to severe. The authors participated in several post-earthquake reconnaissance missions to collect perishable data regarding the damage. This paper is threefold: First, it explores the seismic performance and observed damage in 17 dams (majority embankments) based on data collected from the field. During the seismic activity, embankment dams underwent failure modes such as strength deterioration, yielding, settlement, tension crack formation, as well as sliding along planar or circular surfaces. Second, the paper offers an updated seismic risk analysis for ten selective damaged dams in the regions. Total risk factors are quantified using two different methods. The results show that the majority of the studied dams are classified as high and very high-risk dams. Third, the paper evaluates 11 other dams in the region that were equipped with sensors for monitoring the ground motions. The recorded acceleration at the crest and the abutment are further used to investigate the amount of amplification based on transfer functions. These recordings will be crucial for subsequent model calibration and system identification. Overall, the paper’s objective is to contribute to sharing post-earthquake reconnaissance mission information and to establish the groundwork for in-depth numerical analyses and quantitative risk assessments of dams located in seismically vulnerable areas.
- ItemFabrication of Al/n-GaN/p-Si/Al diodes by thermal evaporation and evaluation of effect of gamma irradiation on device properties(Elsevier, 2024-12) Olkun, Ali; Kaplan, Hüseyin Kaan; Akay, Sertan Kemal; Sarsıcı, Serhat; Erdoğan, Nursev; 414025This study investigates the impact of gamma-irradiation on the material and device properties of Al/n-GaN/p-Si/Al heterojunction diodes. GaN thin films were deposited on glass and p-Si substrates using thermal evaporation, followed by annealing at 450 degrees C. The diodes were subjected to gamma-irradiation doses of 0, 3, and 6 kGy. X-ray diffraction (XRD) measurements revealed significant structural changes, including phase transitions influenced by radiation. Electrical characteristics were assessed through current-voltage (I-V) measurements within the +/- 2 V range. Notably, the ideality factor for the annealed diodes improved from 6.60 to 4.62 and 3.85 with increased gamma-irradiation. The barrier height was determined to be 0.85 eV, and it did not exhibit a significant change upon gamma-irradiation dose. The results provided valuable insights into the response of heterojunction diodes to radiation exposure, aiding in the understanding and potential improvement of the radiation resistance of GaN-based electronic devices.
- ItemHope and psychological resilience in primary caregivers of patients with a chronic mental illness followed in a community mental health center(Elsevier, 2024-03) Erkuş, Şeyma; Babacan Gümüş, Aysun; 372023Purpose: The aim of this study is to examine hope and psychological resilience in primary caregivers of patients with a chronic mental illness. Design and methods: The descriptive study was conducted on 297 caregivers in community mental health centers in Turkey. Data were collected using the Introductory Information Form, Dispositional Hope Scale and the Resilience Scale for Adults. Findings: Hope and psychological resilience of primary caregivers of patients with a chronic mental illness were moderate. To sociodemographic and caregiver characteristics; caregivers who are over 40 years old, lost his/her spouse, low education level, housewife or retired, unemployed, who evaluated their incomes low, mother, living in the same house with the patient, caring for ten years or more, caring for another patient and not getting help in care had lower hope and resilience levels. Compared to patients with a diagnosis of bipolar disorder, caregivers of patients with schizophrenia had lower hope and psychological resilience levels. Conclusions: Primary caregivers of patients with a chronic mental illness should be supported in terms of hope and psychological resilience.
- ItemInvestigation of pepsin levels in bronchial lavage in patients with interstitial lung disease and chronic cough(Elsevier, 2024-11) Ala Çitlak, Fatma Selen; Köksal, Nurhan; Avci, Bahattin; Tibel Tuna, Nazmiye; Güllü, Yusuf Taha; 156045Aim: Pepsin is an enzyme that helps digest protein secreted only from the gastric chief cell in an inactive state. Pepsin is a good marker for acidic gastroesophageal reflux (GER). Its presence in sputum or saliva is considered pathologic. In GER, cough is stimulated by broncho-esophageal neurogenic reflex and aspiration of gastric contents into the airways. GER is the most common cause of cough. Gastric acid reflux is also thought to play a role in Interstitial Lung Disease (ILD) etiology. In many studies, pepsin and bile acid levels in bronchial lavage were high in patients with interstitial lung disease and chronic cough. In our study, we aimed to evaluate pepsin levels in bronchial lavage in patients with ILD and chronic cough and to investigate the relationship between symptoms and reflux treatment. Methods: Between January 2021 and February 2022, 212 patients who underwent bronchoscopy in our tertiary clinic were evaluated. These patients were divided into three groups: 52 patients with interstitial lung disease, 81 patients with chronic cough, and 79 patients who underwent bronchoscopy with a pre-diagnosis of lung cancer as the control group. Bronchial lavage obtained by bronchoscopy was analyzed for pepsin levels. Results: Shortness of breath and cough were the most common symptoms in all three groups. Pepsin levels were 16.71 ± 8.6 ng/ml in the chronic cough group, 15.6 ± 8.9 ng/ml in the ILD group, and 10.58 ± 5.4 ng/ml in the lung cancer (control) group. Pepsin levels in the ILD and chronic cough group were statistically significantly higher than in the lung cancer group (p:0.00). There was no statistical difference between the ILD group and the chronic cough group regarding pepsin levels. It was found that pepsin levels were lower in the three groups who received anti-reflux treatment. There was no difference in pepsin levels between ILD subgroups. Conclusion: Pepsin levels in bronchial lavage were higher in the ILD and chronic cough groups. This suggests that reflux may be involved in the etiology of chronic cough and ILD. Low pepsin values in patients receiving antireflux therapy have shown that occult reflux may occur. In our study, the high level of pepsin in bronchial lavage, especially in the chronic cough and ILD group, may be instructive in the etiology and treatment planning of the disease.
- ItemOutcomes of Liver Transplantation in Infants: A Retrospective Cohort Study(Elsevier, 2024-12) Erbiş, Halil; Kılınç, Eyyüp Mehmet; Fırat, Aynur; Aliosmanoğlu, Çiğdem; Ağca, Mevlüt Harun; Aliosmanoğlu, İbrahim; 104930Background. Liver transplantation (LT) is a crucial treatment for infants with end-stage liver disease, yet specific data on LT outcomes in infants under 12 months old remain limited. This study aims to present the clinical course and outcomes of infants who underwent LT, assessing the impact of demographic and etiological differences on mortality and survival. Methods. A retrospective analysis was conducted on 64 infants (< 12 months) who underwent LT between January 2019 and March 2024. Demographic, clinical, and laboratory data were collected from their medical records. LT-specific details, postoperative complications, and survival data were analyzed. Results. The median age of the infants was 157 days, with 37 boys (57.8%) and 27 girls (42.2%). Biliary atresia was the most common diagnosis (85.9%), and seven infants had undergone a previous Kasai procedure. The median pediatric end-stage liver disease (PELD) score was 15.5. Left lateral segmentectomy was the predominant graft type (60.9%). The median pediatric intensive care unit (PICU) and hospital stays were 5 and 21 days, respectively. Complications occurred in 20 infants (31.3%), with vascular and biliary complication rates both at 12.5%. The overall mortality rate was 17.2%, with early (30-day) and late mortality rates of 6.3% and 10.9%, respectively. The median overall survival (OS) was 204.5 days, and the 1-year survival rate was 32.8%. Kaplan-Meier and log rank analyses showed no significant impact of sex, age, diagnostic groups, graft type, or surgical complications on OS (P> .05). Conclusions. LT in infants can be performed with acceptable morbidity and mortality rates, particularly with increased experience and standardized protocols.
- ItemPost-2023 Türkiye earthquake risk assessment of cascade dams in upper Euphrates basin(Elsevier, 2024-12) Tosun, Hasan; Hariri-Ardebili, Mohammad AminThe southeastern region of Türkiye faced two significant earthquakes on February 6, 2023, causing widespread destruction and substantial damage to various infrastructures. Over forty large dams in the region were affected, leading to potential new earthquake-prone areas due to energy accumulation in neighboring regions. This study focuses on the seismic risk of eight cascade dams on the Peri River, a tributary of the Euphrates main river, following these earthquakes. The dams, including Kalecik, Kigi, Konaktepe, Ozluce, Pempelik, Seyrantepe, Tatar, and Uzuncayir, with heights ranging from 31 m to 146 m, are situated in a region influenced by the North Anatolian Fault Zone. The research advocates for a comprehensive re-analysis of certain large dams, considering the updated seismic specifications and seismological maps of Türkiye. The study explores the hazard and overall risk assessment of these dams, emphasizing the cascade system and highlighting the critical seismic vulnerabilities of Kigi and Ozluce dams, with a particular focus on their implications for water security in the region. Our findings underscore the need for tailored safety measures for each dam, focusing on early defect detection. By adopting a proactive stance and implementing our recommendations, the resilience of these dams can be enhanced, contributing to the overall water security of the region.
- ItemSelecting facility location of gendarmerie search and rescue (GSR) units; an analysis of efficiency in disaster response(Elsevier, 2024-10) Abdulvahitoğlu, Adnan; Vural, Danişment; Macit, İrfan; 382420Disasters, referred to as events that result in physical, economic, and social losses for individuals and disrupt the daily activities of human communities, necessitate ongoing preparedness due to their unpredictable nature. Swift response during and after a disaster is crucial for preserving human life. Hence, it is imperative to initiate planning immediately following a disaster to ensure readiness for various tasks. Given these factors, search and rescue units must carefully select a base location that enables them to promptly reach affected areas. Disasters exhibit unique characteristics across different regions of Türkiye. While some regions are prone to earthquakes, others face the risks of landslides, avalanches, or floods. Consequently, the required measures for disaster management vary from region to region. Nevertheless, when the term “disaster” is mentioned in Türkiye, earthquakes often come to mind due to their frequent occurrence and significant impact. The Gendarmerie Search and Rescue (GSR) units have been actively responding to these earthquakes, renowned for their exemplary institutional discipline and working methods. This study aims to examine the operations and deployment locations of GSR units, which play a crucial role in mitigating the impact of frequent earthquakes in Türkiye, utilizing a SWOT analysis. Additionally, a Multi-Criteria Decision Making-based mathematical model will be employed to optimize task activities and to select the most suitable facility locations for GSR units. The use of mathematical modeling in this context ensures that GSR units are strategically positioned to maximize their operational effectiveness and minimize response times. The results will be evaluated through sensitivity analysis.
- ItemStock price prediction using the Sand Cat Swarm Optimization and an improved deep Long Short Term Memory network(Elsevier, 2025-01) Gülmez, Burak; 222298Stock price prediction remains a complex challenge in financial markets. This study introduces a novel Long Short-Term Memory (LSTM) model optimized by Sand Cat Swarm Optimization (SCSO) for stock price prediction. The research evaluates multiple algorithms including ANN, LSTM variants, Auto-ARIMA, Gradient Boosted Trees, DeepAR, N-BEATS, N-HITS, and the proposed LSTM-SCSO using DAX index data from 2018 to 2023. Model performance was assessed through Mean Squared Error, Mean Absolute Error, Mean Absolute Percentage Error, and out-of-sample R2 metrics. Statistical significance was validated using Model Confidence Set analysis with 5000 bootstrap replications. Results demonstrate LSTM-SCSO's superior performance across all evaluation metrics. The model achieved an annualized return of 66.25% compared to the DAX index's 47.45%, with a Sharpe ratio of 2.9091. The integration of technical indicators and macroeconomic variables enhanced the model's predictive capabilities. These findings establish LSTM-SCSO as an effective tool for stock price prediction, offering practical value for investment decision-making.
- ItemThe effects of two different cold application times on edema, ecchymosis, and pain after rhinoplasty: a randomized clinical trial(Elsevier, 2024-01) Tekin, Yasemin Eda; İyigün, Emine; Karakoç, Ömer; 292320Purpose: This study was performed to determine the effects of different cold application times to the periorbital area after rhinoplasty on edema, ecchymosis, and pain. Design: A randomized clinical study. Methods: Patients were divided into two groups, and cold application was applied to one group for 4 hours and to the other for 48 hours. The cold application was applied with ice packs for 20 minutes every hour to the periorbital region in both groups. Data were collected with the Patient Information Form, Scoring Diagram for Edema, the Scoring Diagram for Ecchymosis, and the Visual Analogue Scale for Pain. Findings: Periorbital edema, eyelid ecchymosis, and pain were not significantly different between the two groups. The mean edema score of the 48-hour group was 0.87 ± 0.93, while the mean edema score of the 4-hour group was 0.70 ± 0.87 (P = .48) on the 2nd day. The mean ecchymosis score was found as 2.03 ± 1.12 in the 48-hour group and 2.10 ± 1.09 in the 4-hour group (P = .817). The mean pain score was 12.50 ± 17.40 in the 48-hour group and 13.00 ± 16.00 in the 4-hour group (P = .98). Conclusions: The effects of 48-hour and 4-hour cold applications are similar. Cold application for 4 hours may be recommended to patients who undergo rhinoplasty, as it is more practical and easier to apply than the 48-hour practice.
