Search Results (2,204)

Background: The benefits of breastfeeding are well recognized. However, exclusive breastfeeding (EBF) rates are well below the Healthy People 2030 Guidelines, with a rapid drop in exclusive breastfeeding over the first 3 months of life. Although breastfeeding support has increased the initiation of breastfeeding, the role of perinatal interventions, particularly in the context of breastfeeding support, remains a topic of contradiction. Methods: This observational study was designed to assess the impact of a unique prenatal educational intervention in rural East Texas. The study had two aims: (1) to determine whether the addition of prenatal breastfeeding education increased the rate of exclusive breastfeeding at four time points, and (2) to assess the impact of hand expression education on breastfeeding exclusivity. Results: Differences in breastfeeding behaviors were seen between those who received the education and those who did not for exclusivity and duration of breastfeeding. Participants who received the hand expression education were 1.79 times more likely to continue EBF practices at three months postpartum, 6.27 times more likely to continue EBF practices at six months postpartum, and 3.34 times more likely to continue breastfeeding at twelve months postpartum than those who did not receive any hand expression education. Conclusion: This study demonstrates that prenatal education is beneficial for increasing breastfeeding exclusivity and duration and underscores its potential to improve maternal and infant health outcomes. Further research is needed to resolve the ongoing debate and advance our understanding of interventions to increase breastfeeding duration. Full article

The study involved measurements of surface tension of liquid binary copper-titanium alloys with respect to their chemical composition and temperature as well as investigations of the liquid alloy–refractory material-gaseous phase system wettability using usual refractory materials, i.e., graphite, aluminum oxide and magnesium oxide. The experiments were performed with the use of the sessile drop method and a high-temperature microscope coupled with a camera and a computer. The aim of this study was to determine the influence of titanium content in the Cu-Ti alloy on the surface tension and contact angle at the interface between the liquid alloy and the refractory material. The influence of temperature on these parameters was also examined. The tests were carried out for copper-titanium alloys with a maximum content of 1.5% wt. Ti, in the temperature range of 1373 to 1573 K. The test results indicate that as the titanium content in the alloy increases, its surface tension increases slightly. However, an increase in temperature causes a decrease in the surface tension of the alloys. In the case of an alloy containing 1.5% wt. Ti, surface tension at a temperature of 1373 K reaches 1351 mN∙m⁻¹, and at a temperature of 1573 K, it decreases to 1315 mN∙m⁻¹. As the temperature and titanium content in the alloy increase, a decrease in the contact angle is observed. The highest values of contact angles were recorded in the case of contact of the liquid alloy with graphite. For an alloy containing 0.1% wt. Ti at a temperature of 1373 K, the contact angle reaches 132°, while at a temperature of 1573 K, it decreases to 128°. For an alloy containing 1.5% wt. Ti, the values of contact angles are 100° and 96°, respectively. However, the contact angles have the lowest values for magnesium oxide. In the case of a temperature of 1573 K and an alloy containing 1.5% wt. Ti, the contact angle reaches 49°. Such a significant impact of titanium content on the contact angles may be due to its high affinity for oxygen (contact with a substrate made of Al₂O₃ and MgO and its reactivity with carbon (contact with graphite). Full article

Underground spaces contain abundant geothermal energy, which can be recovered for building ventilation, reducing energy consumption. However, current research lacks a comprehensive quantitative assessment of its energy recovery. This research evaluates the energy recovery potential of the Xingfu Forest Belt Urban Underground Utility Tunnels. Field experiments revealed a 7 °C temperature difference in winter and a 2.5 °C reduction during the summer-to-autumn transition. A computational fluid dynamics (CFD) model was developed to assess the impact of design and operational factors such as air exchange rates on outlet temperatures and heat exchange efficiency. The results indicate that at an air change rate of 0.5 h⁻¹, the tunnel outlet temperature dropped by 10.5 °C. A 200 m tunnel transferred 8.7 × 10¹⁰ J of heat over 30 days, and a 6 m × 6 m cross-sectional area achieved 1.1 × 10¹¹ J of total heat transfer. Increasing the air exchange rate and cross-sectional area reduces the inlet–outlet temperature difference while enhancing heat transfer capacity. However, the optimal buried depth should not exceed 8 m due to cost and safety considerations. This study demonstrates the potential of shallow geothermal energy as an eco-friendly and efficient solution for enhancing building ventilation systems. Full article

Background/Objectives: Recent prospective studies have shown that selective laser tra-beculoplasty (SLT) is a safe and cost-effective alternative to pressure-reducing eye drop therapy as a first-line treatment for ocular hypertension or open-angle glaucoma. In addition to its comparable efficacy to eye drop therapy, SLT has been particularly effective in delaying the time until a surgical intervention is needed. The aim of our evaluation is to analyze patients who have received SLT following a pressure-reducing procedure. The primary endpoint is the duration until a subsequent interventional or surgical procedure is required. Methods: A retrospective analysis of 98 patients who underwent selective laser trabeculoplasty following a previous pressure-reducing procedure between 2017 and 2023. The statistical analyses included Cox regression and Kaplan–Meier survival estimations. Results: In total, 122 eyes of 98 patients received selective laser trabeculoplasty following a previous pressure-reducing procedure at the Department of Ophthalmology in Freiburg. The median follow-up period was 381.5 days (range 43.25–862.75 days). Approximately 68% of the eyes did not require another pressure-reducing procedure 365 days after the intervention, while about 58% of the eyes remained without another procedure after 730 days, according to Kaplan–Meier analysis. No significant difference was found between the different types of glaucoma regarding the duration until a subsequent pressure-reducing procedure was needed. The study indicated a tendency for patients with pseudoexfoliation glaucoma to undergo a secondary intervention earlier compared to those with primary open-angle glaucoma (p = 0.16). The intraocular pressure before SLT had a significant impact on the duration until the subsequent operation (p = 0.005). Conclusions: SLT is an effective method even after a previous pressure-reducing procedure for patients in whom further pressure-reducing interventions need to be delayed. Full article

The effectiveness of repair work relies on whether the interface substrate can achieve sufficient bond strength when subjected to numerous stresses. This study investigated the bond properties of repaired normal concrete (NC-to-NC) elements, including cube, beam, and U-shaped specimens, after undergoing natural fracture due to flexural and tensile stresses. The specimens were repaired using a polyurethane (PU) matrix by gluing the two parts and applying compression, splitting, and drop-weight impact (DWI) tests to evaluate the bond strength properties. The results revealed that the PU matrix effectively repairs NC substrate with adequate bond strength, which exceeds the minimum allowable bond strength specified in the ASTM ACI 546-06 to rehabilitate damage concrete structures. The reference beams exhibit a peak applied load capacity of 15.6 kN with less deflection than the repaired samples. The compressive strength of the NC-to-NC repaired specimens loaded along and parallel to the interface plane revealed a decrease in compressive strength of 47.3% and 31.5% compared to the NC-R samples, respectively. The mean number of blows at the cracking stages appeared nearly equal for reference and repaired NC-to-NC specimens. The reference specimens exhibited an average number of 24 and 31 blows at the initial and failure stages, respectively, which were higher by 9.1% and 5.2% than the NC-to-NC repaired specimens. The PU binder showed promising results in achieving adequate interfacial bond strength under static and impact loads. Full article

Several researchers have studied how impact loads from impact hazards affect reinforced concrete (RC) slabs. There is relatively little research on impact loading effects on pre-stressed structures. The usage of fibers in structural elements intrigued researchers. In this paper, impact-loaded post-tensioned (PT) slabs with and without Forta-Ferro fibers were compared to post-tensioned slabs with plain concrete and conventional shear reinforcement. Forta-Ferro is a lightweight, low-cost fiber, and hence its effects on slab structural response under impact load deserve to be explored. Post-tensioned slabs’ impact resistance and energy absorption were tested using real-world situations of rapid and severe loads. Four identical 3.3 by 1.5 m concrete slabs were utilized in the experiment. The experiment involved dropping a 600 kg iron ball from 8 m onto each slab’s center of gravity. The slabs’ responses were investigated. The four slab configurations were tested for displacement, energy absorption, and cracking. Forta-Ferro fiber reinforcement is understudied, making this study significant. The study’s findings may help us comprehend fiber-reinforced concrete PT slabs’ impact resistance and structural performance. Engineers and designers of impact-prone buildings like slabs and bridges will benefit from the findings. The study also suggests adding Forta-Ferro fibers to post-tensioned slabs to improve durability and resilience against unanticipated impact hazards. Full article

Traumatic brain injury (TBI) can cause major disability and increases the risk of neurodegeneration. Post-TBI, there is infiltration of peripheral myeloid and lymphoid cells; there is limited information on the peripheral immune response post-TBI in the immature brain—where injury may interfere with neurodevelopment. We carried out two injury types in juvenile mice: invasive TBI with a controlled cortical impact (CCI) and repetitive mild TBI (rmTBI) using weight drop injury and analysed the response at 5- and 35-days post-injury. In the two models, we detected the brain infiltration of immune cells (e.g., neutrophils, monocytes, dendritic cells, CD4+ T cells, and NK cells). There were increases in macrophages, neutrophils, and dendritic cells in the spleen, increases in dendritic cells in blood, and increases in CD8+ T cells and B cells in lymph nodes. These results indicate a complex peripheral immune response post-TBI in the immature brain, with differences between an invasive injury and a repetitive mild injury. Full article

Large ecological restoration projects have been widely implemented across the world since the 20th century, yielding complex ecological, economic, and social results. Today, balancing ecological restoration with local people’s livelihoods is a key issue. Based on the existing literature, this study proposes a “shock adaptation” mechanism to describe the response of rural residents’ livelihoods to the impact of ecological restoration projects. We hypothesize that adaptability varies across the modes of production. To verify our hypothesis, we used the machine-learning-based local projection (LP) method to analyze China’s Three-North Shelter Forest Program (TNSFP), with data for 596 counties from 2001 to 2020. After the TNSFP started, rural residents’ income dropped, rose, and then exceeded the starting point over 8 years. Moreover, significant heterogeneity exists between agricultural and pastoral areas. Agricultural areas recover faster and improve livelihoods, while pastoral areas take longer to bounce back. The results confirmed the “shock adaptation” mechanism and suggested the importance of the mode of production. Policymakers should add more social–ecological indicators to their evaluation systems, allow local communities more self-management, and offer extra help to those struggling to recover from shocks. Full article

Background: Interstitial lung diseases (ILDs) are an heterogeneous group of infiltrating lung pathologies, for which prompt diagnosis and continuous assessment are of paramount importance. While chest CT is an established diagnostic tool for ILDs, there are no formal guidelines on the follow-up regimen, leaving the frequency and modality of follow-up largely at the clinician’s discretion. Methods: The study retrospectively evaluated the indication of chest CT in a cohort of 129 ILD patients selected from the ambulatory care polyclinic at University Hospital of Liège. The aim was to determine whether the imagining acquisition had a true impact on clinical course and follow-up. We accepted three different situations for justifying the indication of the CTs: clinical deterioration, a decrease in pulmonary function tests (at least a 10% drop in a parameter), and monitoring for oncological purposes. The other indications, mainly routine follow-up, were classified as “non-justified”. Radiation dose output was evaluated with Computed Tomography Dose Index (CTDI) and Dose Length Product (DLP). Results: The mean number of CT scans per patient per year was 1.7 ± 0.4, determining irradiation in CTDI (mGy)/year of 34.9 ± 64.9 and DLP in (mGy*cm)/year of 1095 ± 1971. The percentage of justified CT scans was 57 ± 32%, while the scans justified a posteriori were 60 ± 34%. Around 40% of the prescribed monitoring CT scans had no impact on the management of ILD and direct patient care. Conclusions: Our study identifies a trend of overuse in chest CT scans at follow-up (up to 40%), outside those performed for clinical exacerbation or oncological investigation. In the particular case of ILD exacerbation, CT scan value remains high, underlying the benefit of this strategy. Full article

This work employs a multiscale simulation framework to systematically explore the spallation behavior of ductile tantalum (Ta) subjected to high strain rate impacts. The approach integrates macroscopic simulations, utilizing both the Lagrangian mesh and Smoothed Particle Hydrodynamics (SPH) methods, with microscopic molecular dynamics (MD) simulations to dissect the dynamic failure processes of tantalum. The macroscopic simulations, validated against experimental data, demonstrate the effectiveness of the SPH method in accurately capturing the spallation process. An exponential correlation between spallation strength and tensile strain rate has been established. An in-depth analysis of the free surface velocity profile indicates that the pullback signal is associated with microvoid nucleation, where the velocity drop signifies the initiation conditions for microvoid development. Additionally, the rebound rate following the pullback signal reflects the progression of damage within the spallation region. By integrating results across macro- and microscales, this work offers comprehensive insights into the complex spallation behavior of ductile tantalum under extreme conditions, advancing the understanding of its failure mechanisms at high strain rates. Full article

Commutation failure (CF) is one of the most prevalent events in line-commutated converter-based high-voltage direct current (LCC–HVDC) systems. The frequent occurrence of CF poses a significant threat to the safe and stable operation of power grids. The commutation failure prevention control (CFPREV) is the main method to prevent the initial CF, which relies on the detection of a drop in AC voltage. However, its slow fault detection hinders the rapid response of post-fault control, thereby affecting the effectiveness of CF suppression. Therefore, this paper proposes a fast fault detection method based on Bayesian theory. This algorithm can calculate the conditional probability of each variable in a given dataset, effectively mitigating the impact of noise and errors in data to yield precise and dependable results. By processing the collected continuous data and calculating the probability of the existence of a fault point, it determines whether a fault occurs. Based on this method, an improved prevention strategy is proposed, which can effectively enhance the CF resilience of LCC–HVDC systems under AC faults. Finally, using the power systems computer-aided design (PSCAD) platform, the accuracy of the fault probability detection algorithm was verified based on actual engineering data. The effectiveness of the proposed strategy was further validated under three typical fault scenarios, leading to significant improvements: a 64.12% reduction in detection time for three-phase grounding faults, a 69.88% decrease for single line-to-ground faults, and a 36.84% improvement in phase-to-phase fault detection. Additionally, the overall performance of the strategy was thoroughly assessed through extensive simulations covering various fault cases within a selected range of typical faults. The simulations demonstrated the superiority of the proposed strategy in CF mitigation, with a significant reduction in incidents from 89 to 34 out of 150 tested scenarios. This highlights the robustness and reliability of the proposed strategy. Full article

During the fault period, a phase angle jump may occur at the stator or the point of common coupling, which will deteriorate the low-voltage ride-through (LVRT) characteristics of a doubly fed induction generator (DFIG). The existing LVRT studies focus on the impact of a voltage drop on DFIGs but often ignore that of a phase angle jump. The time-domain simulation is accurate in describing the response of a DFIG during the LVRT process, but it is time-consuming for a DFIG with the full-order model. In this paper, by using the voltage magnitude and phase angle of the stator or the point of common coupling as the inputs, and the state variables as the outputs, the transfer function of a DFIG is derived to analyze its response and find the LVRT measures against the voltage drop and, especially, the phase angle jump. Firstly, the differential-algebraic equations of the DFIG are linearized to propose their transfer function model. Secondly, considering its high-order characteristic, a model reduction method for the transfer function of the DFIG using the Schur decomposition is proposed, and the analytical expression of the output variables of the DFIG with the phase angle jump is derived by the inverse Laplace transformation to judge the necessity of the LVRT measures. Finally, the simulation results of the DFIG are provided to verify the accuracy of the transfer function model and its reduced-order form and validate the feasibility of the LVRT against the phase angle jump with the proposed models. Full article

This study examined the impact properties of ultra-high-performance concrete (UHPC) mixtures with steel fiber (SF) and retrofitted with polyurethane (PU) grouting using repeated drop-weight tests. Micro-steel fiber was added to UHPC mixes from 0 to 3% Vf, and PU grouting overlays of 5 mm, 10 mm, and 15 mm were applied. Digital image correlation (DIC) was used to analyze failure modes. The results showed significant impact durability and energy absorption improvements with increased SF content and thicker PU overlays. UHPC-15PU exhibited 363% and 449% higher first crack and failure strengths than UHPC-5PU. DIC analysis confirmed the failure patterns of the U-shaped UHPC specimen under impact load conditions. Full article

The impact of flour particle size and starch damage on the baking properties of wheat flour cultivated in dry climates, focusing on Uzbekistan, was investigated. Given the critical role of bread and flour products in Central Asian diets, understanding grain cultivation’s influence on these products is imperative. Dry climates affect wheat quality, particularly its protein and glutenin content, influencing dough resistance and bread appearance. This study evaluated how flour particle size and starch damage affect baking properties using wheat flour grown in semi-arid regions, aiming to assist wheat growers in post-harvest irrigation decisions. Through a combination of chemical and physico-chemical methods, including particle size analysis, damaged starch measurement, and baking tests, this study elucidated the relationship between flour characteristics and baking performance. Results indicate that smaller flour particle sizes enhance dough-mixing properties, but may adversely affect crumb firmness. Furthermore, high levels of starch damage negatively impact flour quality and baking properties. Importantly, this study underscores the significance of understanding these factors in optimizing wheat cultivation and flour processing for improved bread quality in dry climates. Specifically, results show that for high-grade flour (Sardor), the control sample had a gluten content of 25.6%, with a drop number of 190 and a degree of starch damage of 26.9 units. Conversely, flour samples from locally grown soft wheat demonstrated higher starch damage, ranging from 3.4 to 3.9 units compared to imported samples. Additionally, regression analysis revealed significant coefficients for particle size and starch damage on the amount of wet gluten washed from these flour samples. Full article

Seasonal frozen soil has significant impacts on changes in soil mechanical properties, settlement, and damage to foundations. In order to study variations in the temperature and horizontal freezing force of loess during three-dimensional freezing, a three-dimensional freezing model test of loess was carried out. This experiment analyzed and studied the soil temperature change distribution characteristics, horizontal freezing force distribution rules, and water migration phenomena caused by temperature. The research results show that the temperature change in soil samples exhibits a “ring-like” decrease from the outside to the inside. When the soil temperature reaches the supercooling point, the cooling curve jumps and rises, and this is accompanied by a stable section with constant temperature. In the late freezing period, the temperature rate drops slowly. Under the action of freezing, the horizontal freezing forces at different positions have similar change characteristics and can be divided into four change stages: stable stage, rapid freezing stage, “secondary” freezing stage, and freezing–shrinkage–rebound stable stage. At lower moisture contents, loess samples undergo freeze–thaw shrinkage during the freezing process. During the rapid freezing stage of soil samples, the water in the soil sample migrates and causes secondary freezing. After the rapid freezing stage, the soil temperature continues to decrease, and the horizontal freezing force no longer decreases. Full article