Error Research Articles

Structural validity of the Brazilian version of the quality care questionnaire-palliative care for use in individuals with diabetes mellitus eligible for palliative care

BackgroundThe Brazilian version of the Quality Care Questionnaire-Palliative Care (QCQ-PC) is an instrument designed to assess the quality of care provided in palliative care from the user’s perspective, featuring easy comprehension and applicability. It has demonstrated validity for use in individuals with cancer, but there is a need for validation in other populations due to the scarcity of instruments with this purpose.ObjectiveTo structurally validate the Brazilian version of the QCQ-PC for use in individuals with diabetes mellitus (DM) eligible for palliative care.MethodsThis is a structural validation study of a questionnaire according to the Consensus-based Standards for the Selection of Health Measurement Instruments (COSMIN). The study was conducted with 100 individuals with DM. Data collection occurred in differents care services in São Luís (northeast Brazil) by means of the application of the QCQ-PC and a form with sociodemographic, clinical, and daily habit data. Descriptive data analysis was performed using absolute values, relative frequencies, and measures of central tendency and dispersion. Structural validity was assessed by means of exploratory factor analysis (EFA).ResultsOf the 100 participants included in the study, 66% were female, 54% were single, with a median age of 64 years, 44% were overweight (44%), 77% were on polypharmacy, and 70% were physically inactive. We found that one domain is the most appropriate for use of the QCQ-PC in individuals with DM eligible for palliative care, according to the parallel analysis implemented in the EFA. This domain was named “quality of care”. The fit indices for this one-dimensional internal structure were adequate: Kaiser–Meyer–Olkin test = 0.71, p value < 0.01 in Bartlett’s test, chi-square/degree of freedom = 1.07, comparative fit index = 0.993, Tucker-Lewis index. = 0.991, root mean square error of approximation = 0.028. The QCQ-PC presented factor loadings ranging from 0.480 to 0.883, maintaining a total of 12 items, which demonstrates the adequate relationship between the quality of care domain and its items.ConclusionTherefore, the internal structure with one domain (quality of care) is the most suitable for use in individuals with DM eligible for palliative care by means of the QCQ-PC.

The influential factors of depression among caregivers of children with Cleft Lip and/or Palate: a path analysis based on diathesis-stress theoretical model

BackgroundDepression is the most common psychological phenomenon among caregivers of children with Cleft Lip and/or Palate and affects the quality of life, treatment satisfaction, children’s self-esteem and parent–child relationship. However, Existing studies have limited explanations for the mechanisms that lead to depression in caregivers of children with Cleft Lip and/or Palate. The present study aimed to identify factors influencing depression among caregivers of children with Cleft Lip and/or Palate and to provide a reference point and new ideas for future research.MethodsThis cross-sectional study investigated 248 caregivers at two Cleft Lip and/or Palate treatment centers in China, spanning from April 2019 to July 2020. The diathesis-stress model was used to construct the model, and data analysis was conducted using SPSS 26.0 and AMOS 25.0. Path analysis was employed to test the hypothetical model, and the fit of the model was evaluated using Chi-Square/degree of freedom, Goodness-of-Fit Index, Normed Fit Index, Relative Fit Index, Incremental Fit Index, Tacker-Lewis Index, Comparative Fit Index and Root Mean Square Error of Approximation.ResultsThe study found that the average level of depression among caregivers of children with Cleft Lip and/or Palate was 4.83 (4.79). Additionally, 43.5% of caregivers exhibited depressive symptoms. The fit of the modified path model was found to be satisfactory, with the following indices: Chi-Square/degree of freedom = 1.881, Goodness-of-Fit Index = 0.986, Normed Fit Index = 0.973, Relative Fit Index = 0.919, Incremental Fit Index = 0.987, Tucker-Lewis Index = 0.960, Comparative Fit Index = 0.987, and Root Mean Square Error of Approximation (RMSEA) = 0.060. The results indicated that parenting stress had the greatest direct impact on depression, followed by hope. Indirect effects on depression were observed for optimism, resilience, and coping, which were mediated through perceived social support and parenting stress.ConclusionsThis study suggests that depression in caregivers of children with Cleft Lip and/or Palate was leadingly influenced by parenting stress and hope. Strategies aimed at the key factors are expected to decrease depression.

Translation and validation of the Chinese version of the Attitudes Related to Trauma-Informed Care (ARTIC-C) scale in nursing inters: a psychometric analysis

BackgroundNursing interns, the future nurses, often find it challenging to interact with trauma survivors due to their lack of experience and training. Assessing their attitudes and knowledge in trauma-informed care can improve their clinical performance.ObjectiveTo culturally adapt and assess the reliability and validity of the Attitudes Related to Trauma-Informed Care Scale in Chinese nursing interns.DesignQuantitative cross-sectional design.MethodsThe translation of Attitudes Related to the Trauma-Informed Care (ARTIC) Scale followed guidelines for the cross-cultural adaptation process. A survey was conducted with 490 nursing interns from two colleges in China in February and May 2024, and seven experts evaluated the content equivalence of each item. Reliability and validity were assessed using item analysis, exploratory factor analysis, confirmatory factor analysis, internal consistency reliability, and test–retest reliability.ResultsThe Chinese version of the ARTIC-C retained 35 items and demonstrated high content validity. Exploratory factor analysis revealed a 6-factor structure, explaining 61.887% of the total variance. Confirmatory factor analysis indicated that the 6-factor model adequately represented the scale structure: chi-square/degree of freedom (CMIN/DF) = 1.544, root mean square error of approximation (RMSEA) = 0.045, comparative fit index (CFI) = 0.969, incremental fit index (IFI) = 0.969, Tucker Lewis index (TLI) = 0.966, and standardized root mean square residual (SRMR) = 0.046. The scale had a Cronbach's alpha of 0.916 and test–retest reliability of 0.876.ConclusionsThe Chinese version of the ARTIC-C scale has demonstrated strong reliability and validity, making it an effective tool for measuring Chinese nursing interns' attitudes and knowledge regarding trauma-informed care.

Addressing lung truncation in 99mTc-MAA SPECT/CT for 90Y microsphere radioembolization treatment planning

BackgroundPrior studies have established that macroaggregated albumin (MAA)-SPECT/CT offers more robust lung shunt fraction (LSF) and lung mean absorbed dose (LMD) estimates in 90Y radioembolization in comparison to planar imaging. However, incomplete SPECT/CT coverage of the lungs is common due to clinical workflows, complicating its potential use for LSF and LMD calculations. In this work, lung truncation in MAA-SPECT/CT was addressed via correction strategies to improve 90Y treatment planning.MethodsLung truncation was simulated in 56 cases with adequate (> 90%, mean: 98%) lung coverage in MAA-SPECT/CT by removing slices in ~ 5 mm increments from the lung apices to the diaphragm. A wide range of lung coverages from 100% to < 1% in ~ 2% increments were created. LSF and LMD were calculated with four methods. (1) 2D planar imaging standard (not truncated), truncated lung SPECT/CT data was: (2) used with no corrections (SPECTTrunc), (3) uniformly extrapolated to full lung coverage (SPECTUniform), (4) fit with an empirical model to predict lung counts at full lung coverage (SPECTFit). To determine counts for LSF, full lung volumes, those modified at the lung/liver boundary (Lungs 2-cm), and those isolated to the left lung (Left Lung) were used. The correction methods were then applied to 31 independent cases without full lung coverage (< 90%, mean: 74%). The variations in LSF and LMD estimates from each correction method were analyzed.ResultsAveraged across simulated lung coverages from 40 to 80%, percent errors relative to non-truncated data for SPECTTrunc were (mean ± σ) − 22% ± 15% for LSF and 34% ± 29% for LMD. SPECTUniform had similar errors with 29% ± 26% for both LSF and LMD. SPECTFit yielded the most accurate and precise estimates for LSF and LMD, with errors of 11% ± 20% for both. The Left Lung approach equalized LMD errors in all three correction methods, with percent errors of 3% ± 17% (SPECTTrunc), 2% ± 17% (SPECTUniform), and 4% ± 13% (SPECTFit). In the 31 cases without ground truth LSF or LMD, Left Lung produced highly comparable LMD estimates, with a mean (max) coefficient of variation across the three correction methods of 4% (20%).ConclusionLSF and LMD can be estimated for 90Y radioembolization using truncated lung coverage data in MAA-SPECT/CT. Empirical models to predict lung counts at full lung coverage produced LSF and LMD estimates with minimal bias and uncertainty. With lung/liver boundary adjustments, all SPECT/CT methods assessed in this work yielded LMD estimates comparable to ground truth, even down to 50% lung coverage.

Stochastic analysis of frequency-domain adaptive filters

This study investigates the convergence behaviors of a family of frequency-domain adaptive filters (FDAFs) under both exact- and under-modeling situations. The stochastic analysis is conducted by transforming the frequency-domain equations into their time-domain counterparts. We discuss the transient and steady-state convergence behaviors of four FDAF versions, i.e., the constrained FDAFs with and without step-normalization, the unconstrained FDAFs with and without step-normalization, and we also present the upper bounds of step size for mean stability and mean-square stability. Starting from the expression for the steady-state mean weight vector, this study investigates whether the FDAFs can converge to unknown system impulse responses and optimum Wiener solutions. Moreover, we provide the closed-form minimum mean-square error (MMSE) that each FDAF can achieve. The difference between the current work and our previous one is threefold. First, the presented time-domain analysis is much easier to handle and has a more explicit physical meaning than that in the frequency domain. Second, we here consider an arbitrary overlap factor between consecutive blocks, while our previous analysis only focuses on 50% overlap. Third, the presented MMSE expressions and excess mean-square error (EMSE) approximations have not been given before. Simulations reveal high consistency between the experimental and theoretical results.

Accurate density measurement of a small solid sample using a combination of hydrostatic weighing and pressure-of-flotation methods

Abstract A new high-precision density measurement method for small non-silicon samples was developed. Hydrostatic weighing (HW) and the pressure-of-flotation method (PFM) are high-precision techniques for determination solid sample densities. However, in HW, the uncertainty of the density measurement is quite large when the volume of the sample is much smaller than that of a 1 kg silicon sample owing to the uncertainty of the auxiliary weights during the measurement. Additionally, the PFM is not applicable for measuring the density of non-silicon materials. We developed a new method that combines HW and the PFM. We prepared a small 45 g Si3N4 sphere sample with a diameter of 30 mm. By employing two silicon discs with these masses that were nearly equivalent to the apparent masses of the sample, the same auxiliary weights were used for both the standards and the sample. The new method was validated by measuring the density of the 45 g Si3N4 sphere with a relative standard uncertainty of 4.6 × 10−6, which is significantly lower than that obtained by traditional HW methods. This approach demonstrates substantial improvements in the precision of small-sample density measurements, thus offering a robust alternative to conventional techniques.

Studies of a Mechanically Pumped Two-Phase Loop with a Pressure-Controlled Accumulator Under Pulsed Evaporator Heat Loads

As avionics become more power dense, electronic device cooling has become a significant barrier to aircraft integration. A mechanically pumped two-phase loop (MPTL) is a thermal subsystem that enables near isothermal evaporator operation, which is desirable for electronics cooling. The goal of this study was to integrate an MPTL with a pressure-controlled accumulator and model a predictive control technique to demonstrate improvements for transient, isothermal evaporator operation for MPTLs under pulsed evaporator heat loads. The model predictive controller enables active control of MPTL compressible volume, which has not been demonstrated for pulsed evaporator heat loads. Experimental data were collected to validate a representative numerical model. A pressure-controlled accumulator was added to an MPTL to experimentally characterize the system thermodynamic response for three pulsed evaporator heat loads. Two statistical methods were used to assess the numerical model agreement with the experimental results. Under pulsed evaporator heat loads, the mean percent error agreed within 3.45% and the mean average percent error agreed within 0.74% for the three pulsed evaporator heat loads. Finally, a traditional proportional–integral (PI) controller and an advanced model predictive controller were developed and integrated into the validated numerical model. Both control methods were evaluated for an expanded set of evaporator heat load profiles to analyze transient behavior. For evaporator heat profiles with high heat transfer rates, the model predictive controller can maintain a target ±2 K refrigerant temperature at the evaporator exit throughout the evaporator heat load duration, whereas the PI-controlled MPTL cannot. Through this work, active control of a pressure-controlled accumulator within an MPTL is shown to improve refrigerant isothermal (±2 K) operation when compared to a traditional control technique.

Assessment of changes in environmental pollution by road noise using a scalar measure

The article addresses the issue of assessing the impact of road rebuilding on traffic noise pollution. To assess noise hazards, parameters expressed on the decibel scale were used, and a new measure was proposed - a scalar reference that compares the sound level value to the recommended threshold. This measure is based on Weber Fechner's law, which relates to human perception of changes in sound levels. It was derived through the decibel algebra applied to measurement results and is called the “coefficient of exceedance of the recommended sound level”. Its usefulness was verified by analyzing the results of measurements of traffic and noise parameters before and two years after the reconstruction of a section of the national road in Kielce. An assessment was made of traffic volume, vehicle speed, and road vehicle noise. The analysis evaluated the absolute values, variability and uncertainty of results obtained for the entire year, Fridays and Sundays. Significant differences in traffic parameter values were observed between the lanes entering and leaving the city on weekdays and weekends. The analysis showed a 28% increase in traffic volume following the road reconstruction. The current measure, which compares the difference in noise levels before and after the road reconstruction, indicates that while noise levels have decreased, they still exceed the normative values. For the same parameters, the median coefficient of exceedance decreased by approximately 17%, and the maximum coefficient of exceedance decreased by approximately 15%. The diagnostic usefulness of the coefficient of exceedance was further assessed using noise simulations based on the Cnossos-EU model. These simulations showed the high sensitivity of the proposed scalar noise measure to changes in vehicle speed and traffic volume. The simulations also indicated that to meet the Polish noise normative values, traffic volume would need to reduced by 50%, and the vehicle speed would need to be capped at 50 km/h. Additionally, the simulations suggested that even more stringent traffic restrictions would be necessary to meet the World Health Organization's noise recommendations.

Capnodynamic determination of end-expiratory lung volume in a porcine model of hypoxic pulmonary vasoconstriction.

The capnodynamic method, End Expiratory Lung Volume CO2 (EELV-CO2), utilizes exhaled carbon dioxide analysis to estimate End-Expiratory Lung Volume (EELV) and has been validated in both normal lungs and lung injury models. Its performance under systemic hypoxia and variations in CO2 elimination is not examined. This study aims to validate EELV-CO2 against inert gas wash in/wash out (EELV- SF6, sulfur hexafluoride) in a porcine model of stable hemodynamic conditions followed by hypoxic pulmonary vasoconstriction and inhaled nitric oxide (iNO). Ten mechanically ventilated piglets were exposed to a hypoxic gas mixture and selective pulmonary vasoconstriction. Inhalation of nitric oxide was used to reverse the pulmonary vasoconstriction. Paired recordings of EELV-CO2 and EELV-SF6, were conducted to assess their agreement of absolute values. EELV-CO2 showed a bias of + 5ml kg- 1 compared to EELV-SF6, upper limit of agreement of 11ml kg- 1 (95%CI: 9-13ml kg- 1), lower limit of agreement - 1ml kg- 1 (95%CI: -3- 0ml kg- 1), mean percentage error 34%. Agreement between EELV-CO2 and EELV-SF6 was largely constant but was affected by progressing hypoxia and reached maximum limit of agreement after iNO exposure. Re-introduction of normoxemia then stabilized bias and limits of agreement to baseline levels. EELV-CO2 generates absolute values in parallel with EELV -SF6. Stressing EELV-CO2 with hypoxic pulmonary vasoconstriction and iNO, transiently impairs the agreement which stabilizes once normoxemia is reestablished.

Extracting error thresholds through the framework of approximate quantum error correction condition

The robustness of quantum memory against physical noises is measured by two methods: the exact and approximate quantum error correction (QEC) conditions for error recoverability and the decoder-dependent error threshold which assesses if the logical error rate diminishes with system size. Here we unravel their relations and propose a unified framework to extract an intrinsic error threshold from the approximate QEC condition, which could upper bound other decoder-dependent error thresholds. Our proof establishes that relative entropy, effectively measuring deviations from exact QEC conditions, serves as the order parameter delineating the transition from asymptotic recoverability to unrecoverability. Consequently, we establish a unified framework for determining the error threshold across both exact and approximate QEC codes, addressing errors originating from noise channels as well as those from code space imperfections. This result sharpens our comprehension of error thresholds across diverse QEC codes and error models. Published by the American Physical Society 2024

Validation of the 21st Century Skills Assessment Scale for public health students in Thailand: a methodological study.

This study aimed to develop and validate the 21st Century Skills Assessment Scale (21CSAS) for Thai public health (PH) undergraduate students using the Partnership for 21st Century Skills framework. A cross-sectional survey was conducted among 727 first- to fourth-year PH undergraduate students from 4 autonomous universities in Thailand. Data were collected using self-administered questionnaires between January and March 2023. Exploratory factor analysis (EFA) was used to explore the underlying dimensions of 21CSAS, while confirmatory factor analysis (CFA) was conducted to test the hypothesized factor structure using Mplus software (Muthén & Muthén). Reliability and item discrimination were assessed using Cronbach's α and the corrected item-total correlation, respectively. EFA performed on a dataset of 300 students revealed a 20-item scale with a 6-factor structure: (1) creativity and innovation; (2) critical thinking and problem-solving; (3) information, media, and technology; (4) communication and collaboration; (5) initiative and self-direction; and (6) social and cross-cultural skills. The rotated eigenvalues ranged from 2.12 to 1.73. CFA performed on another dataset of 427 students confirmed a good model fit (χ2/degrees of freedom=2.67, comparative fit index=0.93, Tucker-Lewis index=0.91, root mean square error of approximation=0.06, standardized root mean square residual=0.06), explaining 34%-71% of variance in the items. Item loadings ranged from 0.58 to 0.84. The 21CSAS had a Cronbach's α of 0.92. The 21CSAS proved be a valid and reliable tool for assessing 21st century skills among Thai PH undergraduate students. These findings provide insights for educational system to inform policy, practice, and research regarding 21st-century skills among undergraduate students.

Bidimensional Gegenbauer Polynomials for Variable‐Order Time‐Fractional Integro‐Partial Differential Equation With a Weakly Singular Kernel

ABSTRACTIn this paper, a pseudo‐operational collocation method based on Gegenbauer polynomials is presented to solve a category of variable‐order time‐fractional integro‐partial differential equations with singular kernels. The applications of these functional equations can be revealed in the theory of elasticity, hydrodynamics, heat conduction, and nuclear reactor theory. The pseudo‐operational matrices are constructed utilizing bivariate Gegenbauer polynomials to approximate the solution of the mentioned equation. Then, using the collocation method and resultant matrices, the main equation is converted into a system of algebraic equations that can be solved by Newton's iteration method. Besides presenting a fast and accurate method, an error bound is determined in a Gegenbauer‐weighted space for the residual function obtained from the proposed approach. Finally, several test examples are performed to confirm the reliability and efficiency of the proposed method.

Assessing the Psychometric Properties of Academic Engagement Questionnaire in Nursing Students

Background: Academic Engagement is considered as one of the important factors related to the learners’ academic achievement. It is known as a significant research issue in higher education. The present study aimed to make an instrument for investigating academic engagement among nursing students of Ilam University of Medical Sciences. Methods: The present study is a methodological and cross-sectional research. To localize the academic engagement questionnaire, first, it was translated into Persian using forward-backward method. Then, its content and face validity were evaluated and approved. In order to determine the validity and reliability, the questionnaire was delivered to 120 nursing students and their comments were collected and analyzed. SPSS and AMOS software, statistical tests of exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) were used for data analysis. Results: According to the results, the internal consistency of the questionnaire was confirmed by calculating Cronbach's alpha coefficient (α = 0.906). The EFA and CFA were used to examine the dimensionality of three domains of vigor, dedication, and absorption. Values of Goodness of Fit Index (GFI), Non-Normed Fit Index (NFI), Comparative Fit Index (CFI), and Root Mean Square Error of Approximation (RMSEA) indices were 0.89, 0.92, 0.90 and 0.97, respectively Conclusion: The reliability and validity of the translated academic engagement questionnaire were relatively acceptable in reviewing the academic engagement of medical students, especially nursing students. Future studies should focus on more samples and examine the impact of nurses' background and educational variables on academic engagement.

Predicting and optimizing the wear behavior of centrifugal cast β-TCP/ Mg–2Zn–1Mn alloys: A hybrid artificial neural network—Grey relational analysis approach

This study investigates the wear behavior of temporary implant such as plates and screws made by Mg–2Zn–1Mn alloy reinforced with β-tricalcium phosphate (β-TCP) under both dry and wet sliding conditions. Grey relational analysis (GRA) and an artificial neural network (ANN) model were utilized to predict wear and optimize performance, considering process parameters such as β-TCP content (0%, 2.5%, 5%), load (20, 40, 60 N), sliding speeds (2, 4, 6 m/s), and sliding distances (800, 1600, 2400 m). The wear rate ( Ws) and coefficient of friction (COF) were evaluated using an orthogonal array L27 to optimize both dry and wet conditions. The optimal process parameters obtained through GRA for dry conditions are 5% β-TCP, 20 N, 4 m/s, and 1600 m, while for wet conditions, they are 0% β-TCP, 20 N, 2 m/s, and 2400 m. The experiment was conducted to calculate Ws and COF using the above process parameters. The values of Ws and COF are 0.010149 mm³/m and 0.109 for dry conditions, and 0.001143 mm³/m and 0.128 for wet conditions. The ANN predicted values for dry conditions are 0.010471 mm³/m for Ws and 0.11045 for COF, with error percentages of 3.17% and 1.33%, respectively. Similarly, for wet conditions, the predicted values are 0.001107 mm³/m for Ws and 0.125 for COF, with error percentages of 3.13% and 2.77%. The ANOVA results for the Grey relational grade (GRG) show that load was the most significant factor influencing wear performance, contributing 51.91% in dry conditions and 34.69% in wet conditions. The close alignment of predictions from both models, with overall error percentages below 3.17%, demonstrates their reliability and effectiveness. Field emission scanning electron microscope (FESEM) analysis of worn surfaces under optimal conditions provided insights into the wear mechanisms. This study confirms that GRA and ANN models are highly effective for predicting and optimize the wear behavior.

RBNN with Cycle-based Parameter Updates and its Application to RUL Prediction

Abstract Bayesian neural networks (BNNs) combine Bayesian theory with deep learning, providing a probabilistic interpretation of deep learning models. Traditional BNNs typically assume that network’s parameters follow a standard Gaussian distribution, which may not accurately reflect the actual situation. To address this issue, this paper proposes a Recurrent Bayesian Neural Network (RBNN) that employs two trainable Gaussian distributions as priors. Furthermore, an alternating cycle model parameter updation algorithm is designed accordingly, which not only prevents overfitting to specific data during training but also enhances the robustness of model parameters in error approximation. Additionally, this RBNN module can be integrated with classical neural network architecture conveniently. By integrating the RBNN with a temporal convolutional network (TCN), the effectiveness of the proposed approach was validated using a dataset for remaining useful life (RUL) prediction of gear and bearing components in civil aircraft. Comparative studies show that the integrated model outperforms traditional methods in terms of RUL prediction and uncertainty quantification, offering superior accuracy and robustness, and the RMSE of the RBNN prediction results is reduced by 17.7% and score is increased by 27.5% compared to BNN.&amp;#xD;

Strict Discretization Error Bounds on Quantities of Interest in Transient Dynamics

ABSTRACTThis work proposes a guaranteed error estimator for linear transient elastodynamics, accounting for both time and space discretization errors. The key lies in the definition of a novel dynamic constitutive relation error formulation, which is proven to be a strict bound of the discretization error. Moreover, based on the established dynamic constitutive relation error and the goal‐oriented error estimation framework, strict upper and lower bounds on quantities of interest are also obtained. Numerical examples are conducted to verify the proposed strict bounds and to explore the application of these bounds to adaptive time stepping and mesh refinement.

Synthesis and Characterization of Hydrazine Bridge Cyclotriphosphazene Derivatives with Amide–Schiff Base Linkages Attached to Decyl and Hydroxy Terminal Groups

New cyclotriphosphazene derivatives featuring amide–Schiff base linkages with a hydrazine bridge and different terminal ends, such as decyl alkyl chains and hydroxy groups, were successfully synthesized and characterized. Fourier-transform infrared spectroscopy (FTIR), nuclear magnetic resonance spectroscopy (NMR), and CHN elemental analysis were used to characterize the structures of these compounds. The formation of hydrazine-bridged cyclotriphosphazene derivatives with amide–Schiff base linkages was confirmed by the FTIR spectra, showing a primary amine band for the amide linkage around ~3300 cm−1 and a band for the Schiff base linkage near ~1595 cm−1. This was further supported by NMR analysis, which displayed an amide proton (H-N-C=O) at ~δ 10.00 ppm and an azomethine proton (H-C=N) within the δ 8.40–8.70 ppm range. The 31P NMR spectra of cyclotriphosphazene compounds display a singlet at ~δ 8.20 ppm, indicating an upfield shift that suggests the complete substitution of all phosphorus atoms with identical side chains. Furthermore, CHN analysis verified the purity of the synthesized compounds, with a percentage error below 2%. The introduction of hydrazine bridges and amide–Schiff base linkages into the cyclotriphosphazene core significantly enriches the molecular structure with diverse functional groups. These modifications not only improve the compound’s stability and reactivity, but also expand its potential for a wide range of applications.

Thermal analysis of mineral oil‐based nanofluids of distribution transformers exposed to simultaneous current and voltage harmonics

AbstractThe exact thermal evaluation of distribution transformers (DTs), which are critical and costly pieces of equipment for the power grids, may contribute to preventing the respective failures. Therefore, the present study non‐uniformly investigated DT for correct anticipation of hotspot temperature (HST). Optical fibre sensors (OFSs) were applied for assessing our newly developed non‐uniform 3D computational fluid dynamic (CFD)‐based modelling while performing the temperature rise test (TRT). It should be noted that this new 3D CFD‐based thermal analysis showed an error percentage of 0.11% (0.1°C) in comparison to the OFS measurement, reflecting the ideal efficiency and accuracy of the model. Moreover, thermography for both top‐oil temperature (TOT) and bottom‐oil temperature (BOT) was employed to validate the results from non‐uniform 3D (three‐dimensional) CFD‐based thermal evaluations. The results indicated an acceptable level of relationship between thermography and thermal analysis of 3D CFD at the specified two spots, with an error percentage of &lt;0.65%, demonstrating the acceptable accuracy of the new non‐uniform 3D CFD‐based model. In the following, yet importantly, the new non‐uniform 3D model was subjected to the total harmonic distortions (THD) for the current and voltage of 5%, 10%, and 15%, which raised the HST more than the original model without harmonics by 3.3°C, 7.1°C, and 10.3°C, respectively. Ultimately, different mineral oil‐based nanofluids’, such as multi‐walled carbon nanotubes (MWCNTs) and diamond nanoparticles, influence on the HST decrement of DT in simultaneous current and voltage harmonics was investigated.

Associations of war-related PTSD symptoms with sleep disturbance: The explanatory roles of emotion regulation difficulties and intolerance of uncertainty.

Although associations between posttraumatic stress disorder (PTSD) and sleep disturbance are well-established, relatively little work has examined mechanisms that may underlie this association. This study aimed to examine the explanatory role of emotion regulation difficulties and intolerance of uncertainty (IU) in associations between PTSD symptoms and sleep disturbance among a sample of war-exposed Iraqi individuals. We used structural equation modeling in a war-exposed nonclinical sample (N = 617; Mage = 27.63; SD = 4.81; 46.03% females) to model indirect effects from PTSD symptoms to the sleep disturbance via emotion regulation difficulties and IU. Participants completed PTSD symptoms, sleep disturbance, difficulties in emotion regulation, and IU scales. Significant correlations were found between PTSD symptoms and sleep disturbance. Those who reported higher levels of PTSD symptoms also reported higher levels of sleep disturbance. The structural model was an excellent fit to the data (χ² = 166.03; degrees of freedom = 32; comparative fit index = .960; goodness-of-fit index = .954; Tucker-Lewis index = .943; root-mean-square error of approximation = .082), and all hypothesized indirect effects were significant (ps < .001). Findings add to the emerging body of literature examining potential mechanisms that may help to explain the maintenance or even escalation of PTSD-related sleep disturbance. Findings have clinical implications in designing specialized treatments for individuals with PTSD and suggest focusing on emotion regulation difficulties and IU as potential therapeutic targets that putatively underlie PTSD-related sleep disturbance. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Sustainable Development Goals (SDG): Assessing The Online Homework Management Scale's Invariance Across Gender and College Year

Objective: This study is to validate the Online Homework Management Scale (OHMS) among a diverse sample of 1,192 undergraduate students, aiming to assess its effectiveness in measuring online homework management strategies in alignment with United Nations' Sustainable Development Goals (SDG), particularly Goal 4 (Quality Education). Theoretical Framework: The research is grounded in self-regulation theory, particularly focusing on volitional control, to understand how students manage homework in online environments. Method: A quantitative research design was employed to validate the OHMS. The scale measures six dimensions of online homework management: arranging the environment, managing time, monitoring motivation, emotion management, cognitive reappraisal, and handling distraction. Confirmatory factor analysis assessed the fit of the hypothesized six-factor model using indices such as the Comparative Fit Index and the Root Mean Square Error of Approximation. Measurement invariance across gender and college year was tested to confirm the scale's applicability across demographic groups. Results and Discussion: The results confirmed that the OHMS includes six distinct factors, with invariant latent means across gender and college year. A positive correlation was identified between OHMS, online homework interest, and completion rates. Research Implications: Findings suggest that the OHMS can serve as a valuable tool for educators and researchers to enhance students' online homework management and promote self-regulation skills, supporting educational outcomes aligned with the SDG. Originality/Value: This research provides robust evidence for the validity of the OHMS, underscoring its relevance in assessing online homework strategies among college students, contributing to the achievement of the SDG.