Impact Of Different Positions Research Articles

Machine learning‐based wind‐induced response analysis in rectangular building models with limbs

SummaryThis study investigates the impact of different positions of two limbs on the structural response of a rectangular building model to wind forces. The building's geometry assumes Z and + shapes based on specific limb configurations. Computational fluid dynamics (CFD) simulations are performed to quantify wind‐induced pressures, resulting in wind force coefficients. These coefficients are used to develop predictive machine learning models through Gene Expression Programming, Group Method of Data Handling‐combinatorial (GMDH‐Combi), Model Tree, and Artificial Neural Network (ANN) techniques. The ANN analysis explores various combinations of training algorithms, adaptation functions, activation functions, and performance functions to enhance model accuracy. Among these, the Levenberg–Marquardt (LM) with gradient descent with momentum (GDM) adaptation function and sigmoid activation function exhibit superior performance with high R‐squared values. These predictive models are then employed for a comprehensive comparative assessment of the maximum wind force coefficient (CF, max) concerning different limb positions and angles of attack (AOA). For CF, max vs Limb position, variations of limb position are examined for most critical cases of AOA. Similarly, the study of CF, max vs AOA involves an exhaustive investigation into the variation of AOA for the building with the worst limb position. The analysis reveals that changes in AOA have a more pronounced effect on CF, max compared to alterations in limb position. Interestingly, within the AOA range of 1.5 to 2.5, the CF, max consistently reaches a minimum across all models. However, the relationship between CF, max and the critical structural parameter ‘S' (representing limb position) remains less conclusive for the most significant AOAs.

The effects of different positions on neurodevelopment in preterm infants admitted in neonatal intensive care units: a systematic review protocol

Introduction Preterm birth poses significant challenges to infant health, with neurodevelopmental outcomes often affected. In the Neonatal Intensive Care Unit (NICU), positioning strategies are commonly employed with the aim of mitigating adverse effects and promoting neurodevelopment in preterm infants. However, the evidence regarding the impact of different positions on neurodevelopmental outcomes remains heterogeneous and inconclusive. Objective The aim of this systematic review is to evaluate the effects of different positioning strategies on neurodevelopmental outcomes in preterm infants admitted to Neonatal Intensive Care Units (NICUs). Methods A comprehensive search will be conducted in electronic databases including PubMed, MEDLINE, EMBASE, and Cochrane Library. To comply with the established guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) framework, the systematic review will be conducted to identify relevant studies published up to the date of the search. This systematic review protocol has been registered in PROSPERO to ensure thorough and transparent reporting of the search process, synthesis of findings, and analysis methods. Discussion In the context of preterm infants admitted to Neonatal Intensive Care Units (NICUs), the discussion surrounding the effects of different positions on neurodevelopmental outcomes is multifaceted and warrants careful consideration. Variations in study methodologies, including sample sizes, outcome measures, and follow-up durations, underscore the need for standardized approaches to facilitate comparison and synthesis of findings. The heterogeneity in reported outcomes, ranging from cognitive and motor development to sensory processing, highlights the complexity of neurodevelopmental assessment in this population and emphasizes the importance of comprehensive evaluation frameworks. Through rigorous synthesis and analysis of existing literature, our protocol aims to contribute meaningful insights that can drive future research agendas and enhance neurodevelopmental outcomes for this vulnerable population. Systematic Review Registration number CRD42023492163

Effects of Secondary Fuel Injectors Position and Angle on the Performance of a Miniature Trapped Vortex Combustor

ABSTRACT This paper investigates the impact of different positions and angles of secondary fuel injector on the flow field characteristics, fuel-air mixing, and combustion performance of a miniature trapped vortex combustor (TVC), utilizing a combination of experimental and numerical methods. The numerical computation results show a good agreement with experimental data. Detailed computational findings highlight the significant influence of varying injector positions and angles on miniature TVC performance. Adjusting the positions and angles of secondary fuel injectors lead to notable outcomes: Adjusting the positions and angles of secondary fuel injectors leads to notable outcomes: achieving a more stoichiometric mixture within the cavity, extending the region of intense combustion, and increasing combustion efficiency by up to 3.4%. These adjustments are conductive to enhancing the overall performance of a miniature trapped vortex combustor.

Unlocking the potential of MgF2 textured surface in enhancing the efficiency of perovskite solar cells

In this work, we explored the use of magnesium fluoride (MgF2) based textured surfaces in perovskite solar cells (PSCs) to enhance light trapping and increase conversion efficiency. We studied the impact of different positions of random pyramid arrays (RAs) on reflectance, EQE, JV curve, and PV parameters. Our results showed that this approach led to a conversion efficiency of 24.8% with JSC of 26.12 mA/cm2.

Performance of fire breaks installed within EPS‐insulated façade systems

SummaryExternal Thermal Insulation Composite Systems (ETICS) are used in most European countries for the thermal rehabilitation of existing buildings or as a method to improve the thermal performance of new constructions. This paper describes an ad‐hoc intermediate‐scale experimental study to evaluate the behavior of ETIC systems in case of a fire and shows the impact of different positions and types of fire breaks on global performance. The intention of this experimental intermediate scale methodology is to be used as a screening test and not to replace or reproduce the large‐scale testing regime. The results of this study show that interruption of the combustible insulation may have a contribution in limiting the vertical fire spread and can significantly reduce the damaged area affected by the heat exposure.

Study on Low-Velocity Impact Damage and Residual Strength of Reinforced Composite Skin Structure.

In order to better understand the damage tolerance of reinforced composite plates, the impact damage of the reinforced composite plates was investigated under low-velocity impact test. The experimental results show that the impact of different positions and energies causes different degrees of damage to the specimens, including but not limited to ply fracture, internal delamination of the skin, and debonding of the stiffeners and skin. After impacting, the specimens were tested in an axial compression. The results show that the ultimate bearing capacity of the specimen is also affected by different forms of impact. The impact point has the greatest influence on the specimen while it locates at the intersection of longitudinal and transverse bars. Compared with the intact specimen, the ultimate load carrying capacity was reduced by 16.83% and 44.02%, while the specimen impacted by 15 J and 30 J, respectively. The compression failure mode of the damaged specimen is mainly the breakage of the stiffeners and the delamination of the skin.

Energy consumption of atria; the case of a commercial-office center in the semi-arid climate of Tehran

According to the energy crisis in the world, optimization of energy consumption is indispensable. Technological advances in constructions and application of renewable energy resources demand saving energy. Atrium, as one of the construction elements, catches sufficient daylight and acts as a passive solar element and results in a decline of energy consumption. This research seeks to evaluate the impact of different positions of atrium on its energy performance; this embraces modelling three groups of spatial configuration of atriums in a given four-story building. The total volume and area of atriums in all three groups are equal. DesignBuilder, the energy simulation software, is the platform for simulation and comparison. The results show that the number of atriums does not have a noticeable impact on energy consumption; however, the spatial configuration of atriums, specially the distance of atriums to external walls have a little impact on the annual energy consumption. Based on the purpose of a specific design, one can decide on whether to take into account the discrepancy.

Living in Harmony?

Three societal lines of conflict, “casteism”, communalism, and regionalism, are regarded as severe challenges in present-day India. This article discusses and compares differences between presentations of these lines of conflict in six textbook series for social sciences prepared by the Indian states of Maharashtra and Tamil Nadu, and by the National Council of Educational Research and Training (NCERT) in New Delhi. The variations in perspective, scope, and approach are related to changing educational approaches and to specific discourses of identity politics, which may be explained in terms of the impact of different positions adopted by states and the union towards the issues, and in terms of the discursive dominance of specific sociopolitical viewpoints.

Does pregnancy and/or shifting positions create more room in a woman’s pelvis?

The purpose of this study was to assess the impact of different positions on pelvic diameters by comparing pregnant and nonpregnant women who assumed a dorsal supine and kneeling squat position. In this cohort study from a tertiary referral center in Germany, we enrolled 50 pregnant women and 50 nonpregnant women. Pelvic measurements were obtained with obstetric magnetic resonance imaging pelvimetry with the use of a 1.5-T scanner. We compared measurements of the depth (anteroposterior (AP) and width (transverse diameters) of the pelvis between the 2 positions. The most striking finding was a significant 0.9-1.9 cm increase (7-15%) in the average transverse diameters in the kneeling squat position in both pregnant and nonpregnant groups. The average bispinous diameter in the pregnant group increased from 12.6 cm ± 0.65 cm in the supine dorsal to 14.5 cm ± 0.64 cm (P < .0001) in the kneeling squat; in the nonpregnant group the increase was from 12 cm ± 0.76 cm to 13.9 cm ± 1.04 cm (P < .0001). The average bituberous diameter in the pregnant group increased from 13.6 cm ± 0.93 cm in the supine dorsal to 14.5 cm ± 0.83 cm (P < .0001) in the kneeling squat position; in the nonpregnant women the increase was from 12.6 cm ± 0.92 cm to 13.5 cm ± 0.88 cm (P < .0001). A kneeling squat position significantly increases the bony transverse and anteroposterior dimension in the mid pelvic plane and the pelvic outlet. Because this indicates that pelvic diameters change when women change positions, the potential for facilitation of delivery of the fetal head suggests further research that will compare maternal delivery positions is warranted.

Impact of Pulmonary Venous Locations on the Intra-Atrial Flow and the Mitral Valve Plane Velocity Profile

In this paper we present a three-dimensional computational fluid dynamics (CFD) framework of the left atrium (LA) and its pulmonary veins (PVs). The framework uses magnetic resonance imaging (MRI) to render the subject-specific atrial and venous geometries. The aim was first to investigate the diastolic flow field in an anatomically representative model of the LA and PVs. Second, to investigate the impact of different positions of the PVs on the intra-atrial flow and on the resulting velocity distribution at the mitral valve (MV) plane. Three 3D models with different venous entry locations were created for this purpose. In the model with anatomically based PV positions, the velocity profile at the MV plane showed qualitatively good agreement with the MRI flow measurements. When comparing the flow field in the three models, the results clearly illustrate that the PVs have a significant impact on the intra-atrial flow and the final velocity profile at the MV plane. Because the interpatient variability in PV number and branching patterns is large, the velocity profile at the MV plane should be considered as a subject-specific property. Therefore, we suggest that in order to obtain a physiological correct simulation of ventricular filling and MV opening dynamics, a subject-specific representation of the atrial and venous anatomies should be included in the simulation model.

The Impact of Different Positions and Thoracial Restrains on Respiratory Induced Cardiac Motion

One of the limiting factors for high resolution magnetic resonance coronary angiography (MRCA) is the motion of the heart during breathing. Current approaches use mainly motion correction in one dimension. We aimed to determine the relation between diaphragmatic motion and cardiac motion as well as the potential influence from external restraints reducing thoracical anterior posterior (AP) motion. Four real time navigators were used to collect motion parameters, diaphragmatic cranio-caudal, cardiac cranio-caudal, diaphragmatic anterior-posterior, and thoracical anterior-posterior. Measurements were performed in prone and supine position and supine position with a thorax restraint. In supine, the highest correlation was found between cranio-caudal diaphragmatic and cardiac motion (r2 = 0.71, slope = 0.26; p < 0.05). Prone positioning or external restraints led to significant changes of motion patterns, with a lower correlation between diaphragmatic and cardiac position. External manipulation of breathing by prone positioning or thoracical restraints leads to a less accurate prediction of cardiac position from assessment of diaphragmatic positions compared to standard supine positioning.