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Structural and luminescence properties of alkali-co-doped LiCaBO3: Dy3+phosphors
No full textDysprosium (Dy3+)-doped lithium calcium borate (LiCaBO3, LiCOB) phosphors were synthesized via a sol-gel combustion route and systematically investigated with respect to their structural, vibrational, and luminescence characteristics, with emphasis on the role of alkali co-doping (Na+, K+). XRD with Rietveld refinement confirmed the orthorhombic phase formation, indicating that Dy3+ ions substitute Ca2+ sites, while alkali co-doping provided effective charge compensation and mitigated lattice strain. FTIR and Raman analyses verified the preservation of the borate framework, with Na+ yielding more efficient structural stabilization than K+. Photoluminescence spectra revealed the characteristic Dy3+ blue (4F9/2 -* 6H15/2) and yellow (4F9/2 -* 6H13/2) emissions, enabling quasi-white light generation. The emission intensity was maximized at 2 wt% Dy3+, with quenching beyond this level governed by dipole-quadrupole interactions, as confirmed by Dexter analysis. Alkali co-doping significantly enhanced PL output, with Na+ producing stronger and more stable emission than K+ due to superior charge compensation. Judd-Ofelt analysis based on emission spectra yielded 522, 524, and 526 parameters consistent with experimental lifetimes, demonstrating that Na+ co-doping promotes red-shifted transitions via enhanced 526, whereas K+ favors yellow emission through 522 enhancement. Remarkably, temperaturedependent PL studies showed anomalous thermal enhancement in Dy3+-only samples, while Na+/K+ co-doped systems exhibited trap-assisted recovery with low activation energies (0.21-0.22 eV), indicating excellent thermal stability. Chromaticity coordinates confirmed tunable near-white emission, underlining the potential of alkali-modified LiCOB:Dy3+ phosphors not only for solid-state lighting but also for future radiation detector applications.Deanship of Graduate Studies and Scientific Research, Jazan University, Saudi Ara-bia [JU-20250218-DGSSR-RP-2025]The authors gratefully acknowledge the funding of the Deanship of Graduate Studies and Scientific Research, Jazan University, Saudi Ara-bia, through Project number: (JU-20250218-DGSSR-RP-2025)
Tunable dielectric, electro-optic, and photoluminescence properties of Cu-and Gd-doped ZnO nanocomposites in E7 liquid crystals for device applications
No full textThis study investigates the effects of Cu-and Gd-doped ZnO nanoparticles on the structural, dielectric, electrooptical, and photoluminescence (PL) properties of a nematic E7 liquid crystal matrix. Nanoparticles were synthesized using a microwave-assisted gel combustion method and uniformly dispersed into E7. Dielectric measurements revealed a reduction in permittivity and dielectric strength with both dopants, with Gd:ZnO producing a more pronounced effect. Electro-optical analysis showed that the threshold voltage decreased from 0.78 V (pure E7) to 0.71 V (Gd:ZnO/E7), indicating improved switching characteristics. PL studies demonstrated significant quenching in doped samples, particularly with Gd:ZnO, attributed to deep trap states and non-radiative recombination. Additionally, all doped structures exhibited voltage-induced PL quenching under increasing electric fields. These findings suggest that Cu:ZnO and Gd:ZnO doped LCs offer tunable dielectric and optical responses and are promising candidates for low-power display devices, light modulators, and tunable optoelectronic systems
An alternative software benchmarking dataset: effort estimation with machine learning
No full textEffort estimation plays a vital role in software project planning, as accurate estimates of required human resources are essential for success. Traditional estimation models often depend on historical size and effort data, yet organizations frequently struggle to access reliable effort records. Public benchmarking datasets like ISBSG offer useful data but may lack coverage or involve licensing fees. To address this issue, we previously introduced a free, extendable benchmarking dataset that integrates functional size and effort data extracted from 18 studies. In this study, we examine the effectiveness of our dataset for predictive effort estimation and compare it with the widely used ISBSG dataset. Our analysis includes 337 records from our dataset and 732 ISBSG projects, focusing on those with COSMIC size data. We first developed and compared models using linear regression and nine machine learning algorithms - Bayesian Ridge, Ridge Regression, Decision Tree, Random Forest, XGBoost, LightGBM, k-Nearest Neighbors, Multi-Layer Perceptron, and Support Vector Regression. Then, we selected the best-performing models and applied them to an unseen evaluation dataset to assess their generalization performance. The results show that machine learning performance varies based on evaluation method and dataset characteristics. Despite having fewer records, our dataset enabled more accurate predictions than ISBSG in most cases, highlighting its potential for effort estimation. This study demonstrates the viability of our dataset for building predictive models and supports the use of machine learning in improving estimation accuracy. Expanding this dataset could offer a valuable, open-access resource for organizations seeking effective and lowcost estimation solutions.Scientific and Technological Research Council of Turkey (TUBITAK) ARDEB 1001 [121E389]This research is supported by The Scientific and Technological Research Council of Turkey (TUBITAK) ARDEB 1001 [Project number: 121E389] program. We would like to express our gratitude to all the scientists who contributed to creating this benchmarking dataset by openly sharing the data from their research
Development and psychometric evaluation of the delirium detection and management scale for pediatric intensive care nurses
No full textAim: This research was conducted to develop the Delirium Detect and Management Scale for Pediatric Intensive Care Nurses and investigate its Psychometric Properties. Study design: This methodological study was conducted with pediatric intensive care nurses between January 20 and February 20, 2025. Two hundred thirteen pediatric intensive care nurses were included in the study. The Nurse Identification Form and Delirium Detection and Management Scale for Pediatric Intensive Care Nurses were used in the study. The scale's content validity, explanatory and confirmatory factor analysis, Cronbach's alpha, item-total correlation, and split-half analysis were used in the psychometric analysis. Results: Cronbach's alpha analysis, item-total score correlation methods, and explanatory and confirmatory factor analysis were used in data evaluation. The scale consists of 19 items and three sub-dimensions. In both explanatory and confirmatory factor analysis, all factor loadings were found to be more than 0.30. In the confirmatory factor analysis, all fit indices were determined to be more than 0.80, and the RMSEA value was less than 0.08. Cronbach's alpha coefficients for the entire scale and subscales were 0.93, 0.89, 0.84, and 0.82, respectively. The scale is a practical and reliable clinical tool that helps nurses obtain accurate, consistent, and meaningful patient data. Conclusions: Findings indicated that the developed scale is a valid and reliable tool. Practice implication: Determining the in-service training needs of pediatric intensive care nurses regarding delir-ium, developing their delirium-related care competencies, and increasing the quality of patient care can be achieved. (c) 2025 Published by Elsevier Inc
The association between electrical risk score and non-dipper hypertensive pattern with newly diagnosed hypertensive patients
No full textBackground: The electrical risk score (ERS) is composed of six simple electrocardiography (ECG) parameters: heart rate, presence of left ventricular hypertrophy, QRS transition zone, corrected QT interval, T-peak-to-T-end interval and frontal QRS-T angle. ERS has been shown to improve risk assessment for various diseases. Objective: This study aimed to investigate the relationship between ERS and circadian blood pressure variability. Methods: This study recruited 144 hypertensive individuals who underwent 24 h ambulatory blood pressure monitoring (ABPM). Based on the findings of 24 h ABPM, the study population was categorized into the following two groups: patients with dipper hypertension (HT) and those with non-dipper HT. ERS was measured using 12-lead ECG. Results: The ERS in individuals with non-dipper HT was substantially greater than in patients with dipper HT (2.75±1.07 vs. 2.31±1.03 respectively, p = 0.018). ERS (OR:1.507, 95 % CI:1.060– 2.142; p = 0.022) was independently associated with non-dipper HT according to multivariate analysis. An optimal ERS cut-off value of >2 predicted a non-dipper hypertensive pattern with 59.1 % sensitivity and 56.9 % specificity ([AUC]: 0.604 [95 % CI: 0.519–0.684, p = 0.0263]). Conclusion: This study showed that increased ERS was associated with non-dipper pattern in newly diagnosed patients with HT. © 2025 Elsevier B.V., All rights reserved
Na+-driven enhancement of the 5D0 ? 7F4 emission in Eu3+-activated KCa4(BO3)3: photoluminescence and Judd-Ofelt study
No full textA series of Eu3+-activated KCa4(BO3)(3) (KCOB) phosphors were synthesized using a conventional solid-state reaction method. The structural, morphological, and photoluminescence properties were systematically tuned via Li+ and Na+ co-doping. Rietveld-refined X-ray diffraction confirmed successful substitution of Ca2+ sites by Eu3+ and alkali ions without forming secondary phases. FTIR and Raman spectroscopy validated the stability of the [BO3](3-) unitswhile also indicating local vibrational distortions caused by asymmetry in the crystal field environment. SEM images displayed uniform microstructures with enhanced surface densification upon alkali incorporation. Photoluminescence spectra exhibited strong red emission centered at similar to 613 nm, attributed to the D-5(0) -> F-7(2) electric dipole transition of Eu3+, with intensity enhancement under alkali co-doping due to increased site asymmetry. Judd-Ofelt analysis revealed significant increases in Omega(2) and Omega(4) parameters, particularly in Na+-doped samples, confirming the enhancement of electric dipole transition probabilities. CIE chromaticity analysis showed that Li+ co-doping at y = 0.02 yielded the highest color purity (84 %) and lowest correlated color temperature (CCT approximate to 1940 K), while Na+ co-doping provided moderate-to-high color purity (up to 79 %) with tunable CCT values between 1831and 2038 K. Temperature-dependent PL studies anomalous non-monotonic behavior, including partial intensity recovery at elevated temperatures, deviating from classical quenching models. This suggests the involvement of defect-mediated recombination pathways and strong local crystal field effects stabilizing emission under thermal stress. These findings demonstrate that Li+/Na+ co-doping enables precise tuning of crystal symmetry, emission intensity, chromaticity, and thermal resilience. Thus, KCOB:Eu3+ phosphors with optimized alkali content represent promising candidates for thermally robust, high-purity red emitters in near-UV-pumped warm-white solid-state lighting systems.Scientific Research Projects Coordination Unit of Ege University [32614]; Princess Nourah bint Abdulrahman University, Riyadh, Saudi Arabia [PNURSP2025R16]; Scientific and Technological Research Council of Turkey (TUBITAK) [223M036]We would like to express our sincere gratitude to the Scientific Research Projects Coordination Unit of Ege University (Project Number: 32614), the Princess Nourah bint Abdulrahman University Researchers Supporting Project (Project No. PNURSP2025R16), Princess Nourah bint Abdulrahman University, Riyadh, Saudi Arabia. This study was also financially supported by the Scientific and Technological Research Council of Turkey (TUBITAK, Project No. 223M036)
Anomalous 5D0 ? 7F4 transition induced by alkali ion co-doping in Eu3+-activated K7SrY2(B5O10)3 borates: A Judd-Ofelt and photoluminescence analysis for pc-WLEDs
No full textIn this study, red-emitting K7SrY2(B5O10)(3):Eu3+ phosphors were synthesized via high-temperature solid-state reaction. The effects of Li+ and Na+ co-doping on structural and photoluminescent properties were investigated. XRD and Rietveld refinement confirmed a phase-pure trigonal structure. Under 394 nm excitation, Li+ co-doping induced significant local lattice asymmetry, leading to a remarkable similar to 58-fold enhancement of D-5(0) -> F-7(4) transition, which is typically parity-forbidden. This behavior is further supported by the high Judd-Ofelt Omega(6) parameter (5.42 x 10(-20) cm(2)), indicating enhanced electric dipole character due to symmetry breaking. CIE chromaticity coordinates shifted toward deeper red emission with color purity up to 97.7 % and CCT as low as 2253 K. Temperature-dependent PL confirmed high thermal stability (E-a = 0.190 eV). These results demonstrate that Li+-induced symmetry distortion is a powerful strategy to enhance anomalous red emission, positioning KSYBO:Eu3+,Li+ as a promising red phosphor for pc-WLEDs.Princess Nourah bint Abdulrahman University, Riyadh, Saudi Arabia [PNURSP2025R16]; Scientific and Technological Research Council of Turkey [223M036]We would like to express our sincere gratitude to the Princess Nourah bint Abdulrahman University Researchers Supporting Project (Project No. PNURSP2025R16), Princess Nourah bint Abdulrahman University, Riyadh, Saudi Arabia. This study was also financially supported by the Scientific and Technological Research Council of Turkey (TUBITAK, Project No. 223M036)
Seasonal unit root tests and flexible Fourier form
No full textIn this study, we propose a new seasonal unit root testing that incorporates the flexible Fourier form correction. This approach enhances the seasonal unit root testing procedure against nonlinearities and structural breaks without the need for additional testing. The proposed algorithm can handle these issues automatically. Additionally, we conduct simulation exercises to demonstrate that various forms of nonlinearities and smooth breaks can cause significant size distortions and power losses in standard seasonal unit root tests. However, the proposed approach largely corrects these issues and provides a robust alternative to standard tests under different forms of nonlinearities and structural breaks.Scientific and Technological Research Council of Turkiye (TUBITAK) [117K261]This paper is funded by The Scientific and Technological Research Council of Turkiye (TUBITAK) with grant ID 117K261 under the career development programme
UTILIZATION OF PRECONCEPTION CARE AND ASSOCIATED FACTORS AMONG TURKISH WOMEN
No full textPurpose: The aim of the study was to determine utilization of preconception care and associated factors among women. Material and Methods: This study was carried out at a hospital in Istanbul with 350 women. Data were collected with questionnaires about women's characteristics, a preconception risk assessment, and utilization of preconception care. Results: The rates of women's awareness and utilization of preconception care were found to be 30.3% and 11.4%, respectively. Women with a university education, who worked, had higher income levels than expenses, got married after the age of 18, experienced their first pregnancy, planned their pregnancy, heard about preconception care, and received prenatal care showed significantly higher rates of utilizing preconception care compared to the other group. Out of 96 risks, only women with an education higher than primary school, those who exercised regularly, women who experienced recurrent miscarriages, and those who had knowledge or used folic acid utilized preconception care more than other groups. Conclusion: Women's awareness and utilization of pre-pregnancy care were found to be low and women at risk during pregnancy did not utilize preconception care at the desired level
Intrinsic thermoluminescence and anomalous heating rate effects in undoped K7SrY2(B5O10)3 Phosphors: A combined Tm-Tstop and GOK deconvolution study
No full textThis work offers the first detailed analysis of the thermoluminescence (TL) properties of undoped K7SrY2(B5O10)3 phosphors prepared using a conventional solid-state method. Unlike doped systems, the TL signal in this material originates solely from intrinsic defects, making it a cost-effective and rare-earth-free option for radiation dosimetry. TL glow curves induced by beta-irradiation were analyzed using Computerized Glow Curve Deconvolution (CGCD) in combination with the General Order Kinetics (GOK) model, yielding ten distinct and well-resolved peaks with activation energies ranging from 0.71 to 1.76 eV and frequency factors from 3.4 x 109 to 4.2 x 1012 s-1. The Tm-Tstop analysis confirmed the presence of these ten trap levels and showed evidence of both discrete and distributed trapping sites. In addition, anomalous heating rate (HR) effects and dose-response behavior illustrated non-classical recombination dynamics and a clear transition from linear to sublinear TL response at high doses. These findings indicate that K7SrY2(B5O10)3 can serve as an intrinsically active TL material, potentially suitable for low-cost, rare-earth-free dosimetry.Deanship of Graduate Studies and Scientific Research, Jazan University, Saudi Ara-bia [JU- 20250218 -DGSSR- RP -2025]The authors gratefully acknowledge the funding of the Deanship of Graduate Studies and Scientific Research, Jazan University, Saudi Ara-bia, through Project number: (JU- 20250218 -DGSSR- RP -2025