Linear Coefficient Research Articles

Development of novel multifunctional phase change microcapsules for improving thermal comfort and radiation properties

Microencapsulated phase change materials (MPCMs) have gained widespread application in energy-efficient buildings, aiming to improve thermal comfort and reduce energy consumption. To enhance the engineering feasibility of MPCMs, researchers are now focusing on developing MPCMs with multifunctional properties, beyond single thermal storage functionality. In this study, we proposed a novel and straightforward approach to fabricate multifunctional MPCMs with BaCO3 as shell and a core composed of binary phase change materials (PCMs) and lipophilic-modified graphite (MG) via self-assembly method. The incorporation of BaCO3 shell provides MPCMs with additional resistance to ionizing radiation pollution due to the high atomic number element Ba. Additionally, the incorporation of MG into PCMs enhances its temperature sensitivity. The thermal analysis indicates that the binary PCMs’ composition in MPCMs results in two phase transition temperatures at 3.3 °C and 26.4 °C, making them capable of thermal storage in line with comfortable residential temperatures across different seasons. Furthermore, MPCMs were introduced into cement paste (CPM) and used to construct cement chambers. Adding 10 wt% MPCMs in the CPM chambers placed outdoors in Wuhan (from June 7th to June 9th) led to a 23.8 % decrease in temperature fluctuations compared to the reference sample. Radiation shielding results indicated that the linear attenuation coefficient (μ) of CPM increased by 58.7 %, due to enhanced incoherent scattering and photoelectric effects between high atomic number elements and photons. Additionally, XCOM simulations predicted a strong correlation between MPCM content and μ values, with particularly high accuracy at low photon energies. Overall, the multifunctional MPCMs developed in this study not only offers a new route for reducing residential energy consumption and shielding ionizing pollution, but also broadens the applicability of traditional PCMs in the building and other fields.

Rapid Determination of Trace Ethylene Glycol and Diethylene Glycol in Propylene Glycol-Contained Syrups by Ultrahigh-Performance Supercritical Fluid Chromatography-Mass Spectrometry after Precolumn Derivatization

Ethylene glycol (EG) and diethylene glycol (DEG) are two contaminants known to cause a variety of human health problems, when ingested in certain amounts, they can cause adverse effects such as nephrotoxicity, neurotoxicity and even death. They are widely found in propylene glycol, which is commonly used as a base for pharmaceutical syrups. The aim of this study was to develop an analytical method for the evaluation of EG and DEG in commercially available pediatric syrups. In this study, a fast, simple and reliable ultrahigh performance supercritical fluid chromatography-electrospray ionization-mass spectrometry (UHPSFC-ESI-MS) method was developed. The work involved the evaluation of three derivatization reagents for UHPSFC-ESI-MS. Benzoyl chloride was finally selected as the optimal derivatization reagent. Compared with an approach without derivatization, the present method achieved the separation and detection of EG and DEG efficiently, sensitively and rapidly, and analysis of EG and DEG in syrup formulations was realized within 7 min. The linear determination coefficients of EG and DEG in the concentration range of 0.25–25.0 μg/mL were greater than 0.999. The limits of detection for EG and DEG were 0.02 μg/mL and 0.07 μg/mL, respectively, and the limits of quantification were 0.09 μg/mL and 0.25 μg/mL, respectively. The recovery rates of DEG and EG ranged from 85.5%–108.1% and 86.7%–117.2%, respectively. The absolute values of the matrix effects in the three types of syrups considered were all less than 10%. Meanwhile, a gas chromatography-hydrogen flame ionization detection method was established for cross-testing of the analytical results. In 10 batches of syrup formulations, DEG was not detected by either method. The presence of EG was detected by UHPSFC-ESI-MS in only three batches, none of which exceeded 90.23 parts per million (ppm), with a mean absolute error of 5.95 ppm between the two sets of results. The developed UHPSFC-ESI-MS method was rapid, simple, efficient, sensitive and accurate for the determination of EG and DEG in genuine syrup formulations.

Cardiac structure and function in patients with chronic obstructive pulmonary disease

Abstract Background Chronic obstructive pulmonary disease (COPD) is common and strongly associated with cardiovascular disease, but the pathophysiology has not been fully elucidated. Purpose We aimed to investigate cardiac structure and function in patients with COPD compared to a matched general population. Methods In a prospective cohort study, 796 patients with COPD were included and matched 1:2 on age and sex with controls from a general population study. All participants underwent an examination program including echocardiography. Standardized linear regression coefficients were used to compare cardiac structure and function in patients with COPD vs. controls. Impaired left ventricular (LV) function was defined as a left ventricular ejection fraction (LVEF) <50%, or global longitudinal strain (GLS) <16% (numerical). Impaired right ventricular (RV) function was defined as tricuspid annular plane systolic excursion (TAPSE) <1.7 cm. Diastolic dysfunction was defined as having at least two of the following parameters: E/e’ >14, septal e’ velocity <7cm/s, or lateral e’ velocity <10 cm/s, left atrial volume index (LAVi) >34 mL/m2, or tricuspid regurgitation velocity (TRV) >2.8 m/s. Logistic regression was used to assess associations between having COPD and systolic and diastolic dysfunction. Results Mean age was 70.2 ± 8.3 years and 52% were females. COPD patients had a mean forced expiratory volume in 1 second (FEV1) of 49.4 ± 18.8% predicted. At baseline, 43% of the patients with COPD had hypertension and 10% had diabetes (DM). Additionally, 57% with COPD had cardiovascular disease at baseline, including 12% with ischemic heart disease (IHD), 15% with atrial fibrillation (AF), 6% with heart failure, and 5% with a previous ischemic stroke. Patients with COPD had impaired measures of cardiac structure and function including a lower GLS (COPD vs. controls: 16.3 vs. 19.2%), lower TAPSE (2.3 vs. 2.6 cm), larger LAVi (29.0 vs. 24.7 mL/m2), and higher TRV (2.7 vs. 2.3 m/s), p for all associations <0.001. (See figure). Patients with COPD had a significantly higher prevalence of impaired LV systolic function (OR for GLS <16%: 8.18, 95% CI(6.04; 11.1), p <0.001), impaired RV systolic function (OR for TAPSE <1.7 cm: 2.77, 95% CI(1.63; 4.69), p <0.001), and LV diastolic dysfunction (OR for diastolic dysfunction grade I or higher: 4.00, 95% CI(3.12; 5.13), p <0.001) after adjustment for age, sex, hypertension, smoking, DM, IHD, AF, and lower density lipoprotein. (See figure). Conclusion Patients with COPD had significantly impaired LV and RV systolic function as well as impaired diastolic function compared with individuals from the general population. These findings underscore the importance of recognizing and addressing cardiovascular comorbidities in COPD.

An FBG-Based Method for Load Measurement of a Cylindrical Rolling Element Bearing

Abstract Contact forces between raceways and rolling elements of a bearing stand as crucial operational aspects defining the bearing's performance. While monitoring bearing load through load cells or strain gauges on the shaft or housing is feasible, it may not precisely reflect the distributed load transmitted by the rollers directly to the raceways. This paper introduces a method to calculate these contact forces, relying on a linear assumption correlating the loads to the measured strains on the outer race of a bearing. In our research, we conducted both static and dynamic tests on cylindrical roller bearings through simulations and experiments. We designed an experimental test rig to conduct both static and dynamic experiments and utilized FBG optical fiber sensors for contact force measurement in bearings due to their multiple advantages, including high sensitivity, resistance to corrosion and magnetic interference, and ease of installation on the bearing outer race due to their shape and size. Our findings indicate a consistent linear relationship between contact forces and strains measured on the bearing's outer race. Furthermore, we calculated the linear coefficient K values from three test groups: static tests under simulation study, static tests under experimental study, and dynamic tests under experimental study. The K values obtained from static tests (simulation and experimental studies) and dynamic tests (experimental study) align consistently. Following this, we calculated contact forces in both static and dynamic experiments by multiplying the measured strains with K. Our calculations resulted in an error percentage of less than 2% for static tests and below 5% for dynamic tests, highlighting the accuracy of our approach in determining these contact forces.

Experimental and theoretical study on the physico-mechanical characteristics and radiation shielding capability of hardened alumina sludge waste-cement pastes containing MnFe2O4-nanoparticles

This research investigates the impact of incorporating low-cost MnFe2O4 spinel nanoparticles (MF-NPs) at varying concentrations (0.5, 1, and 2 mass%) on the mechanical and physical properties of blended cement pastes. These pastes were produced by replacing different proportions (5, 10, and 15 mass%) of ordinary Portland cement (OPC) with activated alumina sludge waste (AAS), to promote sustainability. Also, the research examined the gamma radiation shielding effectiveness of certain hardened composites against a 137Cs gamma radiation source with an energy of 661.64 keV using a NaI (Tl) detector (Oxford Model) with 3″ × 3″, amplifier and 16 k multi-channel analyzer. The linear attenuation coefficient (LAC) of all the studded samples were calculated theoretically using a Monte Carlo code MCNP-5 code. The gamma radiation shielding properties were analyzed in depth using a Monte Carlo code MCNP-5 simulation model. The theoretical and experimental results for LAC were found to be in complete agreement. Phy-X/PSD software was applied to estimate the mass attenuation coefficient (MAC) for gamma radiation at various energies, as well as the effective atomic number (Zeff), mean free path (MFP), half-value layer (HVL), and tenth-value layer (TVL). The findings demonstrated that the addition of 0.5% MnFe2O4 nanoparticles (MF-NPs) to blended cement pastes exhibited the best physical and mechanical characteristics, as well as the most effective gamma radiation shielding.

Theoretical framework for the response of barotropic shelf current to along-shelf bathymetric perturbations

Abstract The mechanism underlying the response of barotropic shelf current to along-shelf bathymetric perturbations is rationalized by a one-dimensional vorticity equation. Fourier analysis of the equation in the wavenumber domain suggests that bathymetric features with relatively short length scales in the alongshore direction drive steady cross-shelf velocity undulations when the shelf circulation is against the direction of Kelvin wave propagation (upwelling regime). In contrast, much weaker and non-oscillatory cross-shelf velocity is expected when the shelf circulation is in alignment with propagating Kelvin waves (downwelling regime). The velocity undulations in the upwelling regime result from a positive feedback mechanism associated with potential vorticity (PV) advection; however, the presence of bottom friction restricts such undulations within a few wavelengths. The characteristic wavelength of undulations is determined by when the normalized drag coefficient , where u is the along-shelf mean flow speed, Hs is shelf depth, αs is the bottom slope, f is the Coriolis parameter, and r is the linear drag coefficient. Using this formula, a scale of the cross-shelf displacement distance Yt is proposed, aligning with one-layer barotropic simulations over a large parameter space. The study provides a framework for investigating barotropic cross-shelf exchange caused by shelf circulation over irregular bottom bathymetries.

Structural, elastic and gamma-ray attenuation properties of potassium borate glasses doped with BaO, Bi2O3, or Pb3O4: A comparative assessment

This study investigates the effect of substituting boron oxide (B2O3) with heavy metal oxides (HEMOs) on the structural, mechanical, and gamma-ray shielding properties of potassium borate (KB) glass systems. The glass compositions analyzed include 80B2O3–20K2O and 65B2O3–20K2O-15HEMO (where, HEMO = BaO, Bi2O3, or Pb3O4). All samples were prepared using the melt-quenching method, and their amorphous nature was confirmed through X-ray diffraction (XRD). Fourier-transform infrared spectroscopy (FTIR) had revealed BO3, BO4, and BiO6 groups beside the B–O–B linkages. The density increased with the addition of HEMOs, following the order: Pb3O4 (KB4) > Bi2O3 (KB3) > BaO (KB2) > and pure KB (KB1). This trend was also observed in the molar volume (Vₘ) and oxygen molar volume (Vₒ), while the oxygen packing density (Pρ) decreased. Mechanical properties assessed using the Makishima-Mackenzie model indicated that KB3 exhibited the highest elastic modulus (Yₘ) and Poisson's ratio (μ). The microhardness (Hₘ) followed the sequence KB2 > KB3 > KB4 > KB1, attributed to the higher bonding energy in KB2. Gamma-ray shielding parameters, including mass attenuation coefficients (MAC), were calculated using Phy-X and XCOM software for photon energies between 0.2835 MeV and 1.333 MeV. KB4 (Pb3O4) showed superior shielding performance with the highest linear attenuation coefficient (LAC) and the lowest half-value layer (HVL) and mean free path (MFP). Despite KB4's high density, KB3 (Bi2O3) is suggested as a more suitable candidate for radiation shielding applications due to its balanced combination of mechanical strength and γ-ray attenuation efficiency.

Reduction of TCF effect in FBAR devices using DC bias

This study investigates the effect of applied DC bias on the resonant and antiresonant frequency of FBAR devices. In our model, we introduce linear electrostrictive coefficients and compare the theoretical results with experimental data. The FBAR structure utilizes an air cavity as the acoustic reflector layer, with Mo and AlN as the materials for the top/bottom electrodes and the piezoelectric layer, respectively. The resonant and antiresonant frequencies of the FBAR are designed at 2313.1 and 2374.7 MHz, respectively. Under an applied DC bias ranging from −10 to +10 V, the frequency shifts for the resonant and antiresonant frequencies are 37.7 and 27.7 ppm/V, respectively. The theoretical results, incorporating linear electrostrictive coefficients N=−7×1010 and G=−5×109, show excellent agreement with the measured results of the FBAR device. Finally, we compensated for the frequency drift by applying a 20 V DC bias at high temperatures to the FBAR device. These findings have significant implications for improving the performance of RF communication systems in varying temperature environments.

Outcomes of antenatal depression in women and the new-born: a retrospective cohort study.

To determine what effect maternal antenatal depression has on pregnancy and infant outcomes in the Lleida health region. Retrospective observational cohort study in pregnant women between 2012 and 2018 in the Lleida health region. Variables included age, body mass index, caesarean section, pre-eclampsia, birth weight, and Apgar score. We performed multivariate analysis, with linear regression coefficients and 95% confidence interval (CI). Antenatal depression was diagnosed in 2.54% pregnant women from a total sample of 17177. Depression is significantly associated with a higher risk pregnancy and low birth weight. Pre-eclampsia, 1-minute Apgar score, and caesarean section were not significantly associated with depression. Antenatal depression increases the risk of pregnancy complications. In addition, depression in the mother increases the probability of low birth weight.

Advancing gamma radiation shielding with Bitumen-WO₃ composite materials

This research focuses on a manner in which bitumen-WO₃ (petroleum-derived bitumen mixed with tungsten trioxide nanoparticles) materials can be a good shielding candidate against gamma radiation. The objective we set in mixing WO₃ nanoparticles with bitumen was to take advantage of both the bitumen's natural qualities and the WO₃'s excellent shielding capabilities. The prepared composites were tested against various gamma-ray energies emitted from multiple gamma-ray sources to examine their shielding capabilities. The X-ray diffraction (XRD) analysis of the composites' structural properties verified the effective integration of the WO₃ with the bitumen structure. Scanning electron microscopy (SEM) showed that microstructural changes, such as an increase in material density and an improvement in particle dispersion, are caused by a rise in WO3 concentration, which is an essential step toward efficient shielding. Then, the Mean Free Path (MFP), Half-value Layer (HVL), and Linear Attenuation Coefficients (μl) were computed, showing that the composite's capacity to reduce gamma radiation is much enhanced by raising the WO₃ content, especially at lower gamma-ray energies. For instance, at 20 keV, the LAC of 50 wt% WO₃-bitumen composite increased to 9.18 cm⁻1 compared to pure bitumen's 0.40 cm⁻1, while the HVL decreased from 1.73 cm to 0.08 cm, and the MFP dropped from 2.3 cm to 0.1 cm” The results demonstrate the potential of bitumen-WO₃ composites as a sustainable and efficient material for radiation shielding, particularly highlighting their applicability in various sectors, including the development of building wall paints against gamma radiation.

Unveiling the shielding potential: Exploring photon and neutron attenuation in a novel lead-free XCr2Se4 chalcogenide Spinals alloys with MCNP 4C code

The study covers shielding properties of three promising lead-free XCr2Se4 alloys, where X represents Mn, Cu, or Ag, across a spectrum of energies between 0.02 MeV and 15 MeV. MCNP4C was employed to simulate the mass attenuation coefficient (MAC) for the three selected alloys. After being prepared using the conventional solid-state reaction method, the samples displayed densities ranging from 5.45 g cm−3to 6.22 g cm−3. The simulated results obtained from the MCNP4C are then benchmarked with data obtained using different software such as Phy-X, Py-MLBUF, EPIXS, and GRASP. Upon comparing the acquired results with the Phy-X data, a notable correlation was observed with a relative difference ranging from 0.11% to 8.57%. The accuracy of the simulated data was additionally validated through the Kolmogorov-Smirnov test. From the simulated MAC, different ionizing radiation shielding properties including linear attenuation coefficient (LAC), half-value layer (HVL), mean-free path (MFP), transmission factor (TF), radiation protection efficiency (RPE), and fast neutron removal cross section (FNRCS) were calculated to provide a comprehensive analysis of the samples' efficacy in dealing with different types of radiation. The LAC for neutrons at different energies is also examined. HVL analysis indicates the radiation-blocking capacity of the samples. The TF shows the alloys’ ability to either permit or restrain the transfer of radiation. Additionally, RPE and FNRCS give indication of the shielding potential of the studied samples. This study is important for nuclear physicians and researchers and serves as useful data for the development of superior shielding materials.

Influence of Participatory Negotiation on Performance of HIV/AIDS Community Health Projects in Kisumu County, Kenya

The United Nations has noted with concern that around 38.5 million across the globe live with HIV/AIDS. Globally, HIV/AIDS community health projects have been implemented and has influenced significantly the health sector with government and NGOs working together to shape agendas related to health. Therefore, there are efforts to combat HIV/AIDS internationally through Sustainable Development Goal and intensification of efforts to reinvigorate the global community. Based on the foregoing, the study examined how Participatory negotiation influences performance of HIV/AIDS community health projects implemented by Non-Governmental Organizations in Kisumu County, Kenya. This study was grounded on stakeholder’s theory as well as theory of change because the HIV/AIDS community health projects in Kenya is a results-oriented. The research design was descriptive cross-sectional survey which allows the use of both qualitative and quantitative methodologies of gathering data. The target population for this study will be a total of 30,118 comprising 59 monitoring and evaluation officers, 59 project managers and 30,000 beneficiaries of the HIV/AIDS community projects in Kisumu County. The study will purposively select 59 HIV/AIDS project managers and 59 Monitoring and evaluation officers. Using Krejcie and Morgan (1970) formula, the study used a sample size of 379 beneficiaries selected through simple random sampling technique. The study used structured questionnaire to collect quantitative data. Quantitative data was analyzed by using descriptive statistics of frequencies, percentages, mean score and standard deviation with results tabulated and presented on tables and graphs, as well as inferential statistics of Pearson correlation analysis and regression analysis. The simple linear regression coefficients as well as the Pearson correlation results indicated that there was significant effect of Participatory negotiations on Performance of HIV/AIDs Community Health Projects. The small p-values; implied that there was a significant effect of Participatory negotiations on Performance of HIV/AIDs Community Health Projects. The project managers and M&E officers should design appropriate implementation strategies for the health projects that will enable Participatory negotiation practices to be properly implemented in order to enhance performance of community HIV/AIDS health projects.

Enhanced optical and structural traits of irradiated lead borate glasses via Ce3+ and Dy3+ ions with studying Radiation shielding performance

Lead borate glass is the best radiation shielding glass when lead is in high concentration. However, it has low transparency after radiation exposure. Radiation decreases transparency due to chemical and physical changes in the glass matrix, such as creating or healing defects in the glass network. The addition of rare earth elements like cerium and dysprosium oxides to lead borate glasses can improve their transparency and durability as radiation shielding barriers. The newly manufactured glasses’ optical absorption, structural, and radiation shielding properties were measured. The optical characteristics of the generated samples were examined to determine the effect of the cerium/dysprosium ratio on the structural alterations, specifically in the presence of bridging oxygen (BO) and non-bridging oxygen (NBO). Incorporating Ce3+ results in peaks at 195 nm for borate units, 225 nm for Ce3+, and a broadened peak at 393 nm due to overlapping peaks for Ce3+ and Ce4+ in the UV region. By adding Dy, multiple peaks are observed at 825, 902, 1095, 1275, and 1684 nm, corresponding to the transition from 6H15/2 ground state to 6F5/2, 6F7/2, 6F9/2, 6F11/2, and 6H11/2. The samples were also tested before and after exposure to gamma irradiation from a 60Co source at a dose of 75 kGy to assess their stability against radiation. The energy gap value during irradiation shows decreased non-bridging oxygen. The energy gap difference before and after irradiation for the M4 sample shows higher NBO to BO conversion, reducing radiation damage and improving structural stability. Furthermore, X-ray photoelectron spectroscopy was utilized to get insight into the coordination chemistry of the created glass samples. The half-value layer (HVL), radiation protection efficiency (RPE), neutron removal cross-section (FRNCS), mean free path (MFP), mass attenuation coefficients (MAC), and effective atomic numbers (Zef) of the glassy structure were calculated theoretically to assess its radiation shielding qualities. The linear attenuation coefficient order for the prepared samples was M1 > M2 > M3 > M4. The FRNCS values were 0.090, 0.083, 0.081, and 0.079 cm−1 for samples M1, M2, M3, and M4, respectively.

Designing the Next Generation of Polymers with Machine Learning and Physics-Based Models

Abstract The development of next-generation polymers necessitates optimizing several key properties simultaneously, a task that is expensive and infeasible using traditional trial-and-error experimental approaches. A promising alternative is employing a combination of machine learning and physics-based tools to rapidly screen the polymer design space and provide suggestions of new polymers that meet the critical properties required for industrial applications. In this study, we introduce a comprehensive workflow that utilizes machine learning and molecular modeling approaches to design new polymers with the focus on improving five polymer properties: (1) glass transition temperature, (2) dielectric constant, (3) refractive index, (4) stress optic coefficient, and (5) linear coefficient of thermal expansion. Using a small dataset (<200 unique polymers), we developed quantitative structure-property relationships (QSPR) models to accurately predict the experimental polymer properties for both homo- and co-polymer systems. We tested several ML algorithms and identified the best models for predicting these polymer properties, achieving test set R2 greater than 0.77 across all properties. We then explored new polymers by creating a library of over ~10,000 homopolymers using R-group enumeration tools and applied the trained QSPR models to rapidly predict the five polymer properties. The predictions of QSPR models were used to create a multi-parameter optimization score, which helped downselect the large polymer space to ~10 promising candidates. The properties of these selected polymer candidates were subsequently validated with classical molecular dynamics simulations and density functional theory, revealing a strong correlation with the QSPR model predictions. Finally, one of the top candidates was validated by experiments, which showed good agreement against QSPR and physics-based models. Our workflow underscores the power of combining data-driven and theoretical methods in the polymer design process given a small dataset size, offering a valuable resource for experimentalists looking to leverage computer-aided strategies in materials innovation.

Exploring the diverse modifiers influence on the structural, physical, and mechanical properties of a zinc oxide-based boro-tellurite glass system for enhancing radiation shielding performance

This work is meant to fabricate zinc boro-tellurite (ZnO–TeO2–B2O3) glass systems with various modifiers, including MoO3, Bi2O3, and PbO, using the melt quench technique. Four glass samples were produced, each comprising 20 % of a specific modifier from the total weight percent of the neat glass system. Each glass sample is given a code: TBZn, TBZMo, TBZBi, and TBZPb. The XRD results showed an amorphous nature for all glass samples. The FTIR results showed the functional groups for borate and tellurite oxide. The mechanical properties were reduced when different oxides were added instead of ZnO. For example, Young's modulus decreased for glass samples; their recorded values for Young's modulus are 74.516, 72.569, 60.526, and 59.272 GPa for TBZn, TBZMo, TBZBi, and TBZPb, respectively. On the other hand, adding Bi2O3 and PbO led to enhanced shielding properties. For instance, the linear attenuation coefficient values for TBZn, TBZMo, TBZBi, and TBZPb at 0.015 MeV are 168.739, 115.656, 380.711, and 279.162, respectively. Also, the radiation protection efficiency (RPE) at 5 cm and 600 keV is 83.220 %, 79.299 %, 93.919 %, and 90.222 % for TBZn, TBZMo, TBZBi, and TBZPb, respectively. While adding different oxides decreased stability in the current glasses, it also enhanced their shielding properties, recommending their use in the radiation shielding field.

Research on the electromagnetic ultrasonic detection method of initiation crack based on multi-acoustic coefficients fusion

Abstract The traditional single acoustic coefficient cannot judge the different degrees of fatigue damage such as initiation crack and crack extension. Based on the law between the structural evolution of dislocation pile-up initiating crack and acoustic coefficients, a multi-acoustic coefficients fusion feature-fatigue damage stage detection method is proposed. By extracting the nonlinear features as well as linear features of the multi-point detection signals for a single fatigue-damaged aluminum plate, achieves the fatigue damage state. Experiments verified multi-acoustic coefficients with different features corresponding to different fatigue stages such as initiation crack and crack extension.The peak points of the acoustic nonlinear coefficients are used for the judgment of the initiation crack stage, and the peak-to-peak amplitude of the acoustic linear coefficients are used for the judgment of the crack extension stage. Comparing and analyzing the results of electromagnetic ultrasonic detection and microscopic observation of different fatigue damage stages, the proposed method provides early warning of the initiation crack and crack extension by studying the characteristics of acoustic coefficients of different fatigue damage stages. This study provides theoretical and experimental basis for the application of electromagnetic ultrasonic assessment of fatigue damage in metallic materials.

Bio-Adsorbent for Elimination of Reactive Dye from Aqueous Solution: Kinetic and Statistical Modelling Study

Introduction/Background: The use of various dyes to colour products is a general practice in various industries. The occurrence of these dyes in water, even at small concentrations, is highly noticeable and aesthetically objectionable. In the present study, the applicability of inexpensive and eco-friendly bio-adsorbent has been tested as an alternative substitution of the commercially available activated carbon for the removal of reactive dye from the aqueous solution. Materials and Methods: Bio-adsorbent prepared from pomegranate peel was successfully used to remove the reactive dye (Reactive Black 5) from the aqueous solution. The effects of major parameters such as pH, adsorbent dosage, and contact time on dye removal efficiency were studied. Statistical models were articulated based on selected variables to optimize the decolourisation efficiency of the adsorption process using a full factorial central composite design. Results: Dye removal efficiency of close to 100% was observed at a pH 12 using 1 g adsorbent/ 200 mL dye solution within a contact time of 60 min., yielding a virtually colourless solution. A fixed-bed column study with an initial dye concentration of 100 mg/L at bed depths of 4 cm, 8 cm, and 12 cm yielded a breakthrough time of 300 min, 570 min, and 780 min, respectively. Discussion: Langmuir, Freundlich, and Temkin isotherm models were applied to analyze the sorption equilibrium parameters. The experimental results of the analysis revealed that the Langmuir isotherm fits better than the other isotherms with a linear regression coefficient (R2) of 0.99. The high correlation coefficient (R² > 0.95) and low p-values (< 0.0001) indicate that the model and its terms are significant, making it effective for optimizing operational parameters and accurately predicting the response. Conclusion: The breakthrough curve serves as a tool to evaluate the effectiveness of the prepared adsorbent in real-world applications. The present work not only provides an alternative to commercially available activated carbon for dye wastewater colour removal but also emphasizes the importance of repurposing fruit residues, which could otherwise become environmental pollutants if improperly disposed of.

Pengaruh Capacity Building dan Motivasi Kerja terhadap Produktivitas Kerja Pegawai Puskesmas Limo

UPTD Puskesmas Limo is a regional public health center for Limo sub-district which is underpinned by the health department and health facilities managed by the local government. The health Dcenter has the responsibility of providing primary health services to the people of Limo city. With these demands and types of work, training or employee self-development is needed to hone employees' abilities and work motivation. To find out how much influence capacity building and work motivation have on the productivity of UPTD Puskesmas Limo employees, this title was raised. This study uses quantitative methods using non-probability sampling techniques, namely saturated sampling techniques. The sample of this study amounted to 50 people. Then tested quantitative statistical analysis, multiple linear regression analysis and coefficient of determination analysis using a data processing program, namely SPSS 25 software. This study found the results using the t test stated that Capacity Building partially has a significant effect on work productivity with a significant level of 0.02 <0.05 and the t test results of 3.021> 2.008. and work motivation partially has a positive and significant effect on work productivity with a significant value of 0.01 <0.05 and a t test value of 3.146> 2.008 Capacity Building d is a positive and significant effect on work productivity.

Semen static oxidation-reduction potential is not helpful in evaluating male fertility.

Infertility affects a significant percentage of couples worldwide, with male infertility contributing substantially in a considerable number of cases. Research indicates that oxidative stress is a critical factor impacting male fertility. To explore the relationship between semen static oxidation-reduction potential (sORP), sperm parameters, and validated biomarkers of oxidative stress in infertile men. This cross-sectional study involved 202 men diagnosed with idiopathic male factor infertility and male partners from couples with unexplained infertility. Multivariable linear regression to query the associations between sORP, sperm parameters, and oxidative aggression biomarkers (lipid peroxidation, mitochondrial membrane potential, annexin V, and sperm DNA fragmentation). SORP has no linear association with any semen analysis parameter. Furthermore, its relationship with validated biomarkers of oxidative stress was inconsistent. sORP was inversely related to lipid peroxidation (multivariable linear regression coefficient: -0.64), positively associated with sperm DNA fragmentation (multivariable linear regression coefficient: 3.20), and unrelated to mitochondrial membrane potential or annexin V. There is no clear or consistent relationship between sORP and validated oxidative aggression biomarkers or sperm parameters. Our findings suggest that sORP is unlikely to be helpful in the evaluation of a male with idiopathic infertility.

Investigating radiation shielding parameters for X-ray attenuation at various energies in locally produced ceramic materials used in Saudi Arabia

To assess shielding effectiveness against X-rays, a number of locally collected ceramic samples were obtained from the Kingdom of Saudi Arabia. Based on elemental analysis, all of the ceramic samples have a density in the range of 1.68–1.85 g/cm3, with the highest proportions of O, Si, C, and Al atoms and the lowest amounts of Na, Mg, K, Ca, Ti, and Fe. The 320 kV X-ray source (Gulmay Limited, Byfleet, UK) was used to assess the attenuation properties of the ceramic samples. An Exradin A4 ionization chamber (Standard Imaging, Middleton, USA) connected to a UNIDOS electrometer (PTW, Freiburg, Germany) in the control room was used to detect the attenuation properties. Several X-ray attenuation coefficients are evaluated at different X-ray energies in the range of 40–150 kV in this study. These include the mass attenuation coefficient (MAC), linear attenuation coefficient (LAC), half-value layer (HVL), tenth-value layer (TVL), and mean free path (MFP). The ability of any ceramic sample under investigation to shield radiation at low X-ray energy is indicated by the theoretical and experimental values of LAC. The potential applications of these easily accessible, reasonably priced ceramic materials for radiation protection in X-ray labs and low-energy X-ray shielding in a variety of fields have been shown by this investigation.