Strength Analysis Research Articles

Count-rate management in 131I SPECT/CT calibration

BackgroundSystem calibration is essential for accurate SPECT/CT dosimetry. However, count losses due to dead time and pulse pileup may cause calibration errors, in particular for 131I, where high count rates may be encountered. Calibration at low count rates should also be avoided to minimise detrimental effects from e.g. background counts and statistical fluctuations. This paper aims to present experimental data illustrating count-rate dependencies and to propose practical routines to mitigate errors in the 131I calibration procedure without needing advanced analysis tools.ResultsThe sensitivities of two General Electric (GE) Discovery 670 Pro systems were assessed using two Jaszczak phantom geometries. SPECT/CT data were collected over two months, starting with an initial 131I content of > 2 GBq, decaying to approximately 20 MBq. This allowed for a detailed analysis of count losses due to dead time and pulse pileup. From the sensitivity analysis, it was shown that robust calibration was obtained for 131I phantom activities ranging between 250 and 1500 MBq.ConclusionsThe results show that adequate corrections for dead-time and pulse-pileup counting losses are essential for accurate calibration. It is argued that loss corrections should be based on total spectrum count rates in projections and not only on the 364.5 keV energy window data. The measurement campaigns presented in this paper, using basic tools and equipment, may serve as a model for establishing routines for count-loss corrections as well as for system calibration and regular control of system sensitivity. The data suggest that analysis of source and count concentration in a homogeneous Jaszczak phantom offers robust calibration, whereas analysis of source strength and counts in a delineated phantom insert offers a practical and robust method for regular quality control.

Fly ash stabilised red mud as a one-part alkali-activated sustainable material for pavement subgrade: Strength, durability and life cycle assessment analysis

In this study, the viability of using red mud (RM) as an alkali source and fly ash (FA) as an aluminosilicate source for making all waste-based one-part alkali-activated material without commercial activators for pavement subgrade has been evaluated. The study reveals that the UCS and CBR increase with the increase in FA percentage up to 40% and then decrease. UCS of RM increases from 0.31 MPa to 1.17, 1.56, 2.12, and 1.71 MPa for 20%, 30%, 40%, and 50%, respectively. One-part alkali-activated RM-FA with 30% FA was identified as the optimum mixture. Microlevel investigation reveals the formation of N-A-S-H and C-S-H. The resilient modulus (Mr) was found to be 80 MPa for 30% FA sample cured for 28 days. The heavy metal concentration in one-part alkali-activated RM-FA samples is within the acceptable limit. The environmental impact assessment shows the one-part alkali-activated RM-FA to be an environmentally friendly pavement subgrade material.

Posttraumatic resilience and growth: A network analysis of character strengths among sexual assault survivors.

Defined as dispositional qualities that elevate well-being, character strengths such as love and kindness can be developed and enhanced to improve quality of life. Yet, little is known how specific strengths are associated with posttrauma mental health. The present study explored their concurrent associations with posttraumatic stress symptoms (PTSS) and posttraumatic growth (PTG) in a sample of 405 women sexual assault survivors. We applied network analysis to investigate the structure of character strengths, PTSS, and PTG, as well as to identify character strengths most strongly associated with lower PTSS and greater PTG. Results revealed that the strengths of love and forgiveness were most strongly linked to lower PTSS, whereas spirituality and kindness were most strongly linked to greater PTG. These findings highlight character strengths that may be most important to cultivate in trauma-focused care for survivors. (PsycInfo Database Record (c) 2025 APA, all rights reserved).

Relevance of body weight adaptation and modern obesity-defining parameters in the analysis of isokinetic trunk strength in people with obesity - A retrospective analysis.

Pathologic values of body mass index (BMI), body weight, and waist circumference correlate with higher absolute and lower relative trunk strength. Whether waist-to-height ratio (WHtR) is appropriate for showing trunk strength differences in people with obesity and whether a continuous linear relationship exists between the increase in obesity and trunk strength is unknown. This retrospective cross-sectional study included 1174 subjects (1114 men and 60 women). Measured values included body weight, height, waist circumference, WHtR, BMI, and both absolute and body weight-adapted trunk flexor/extensor strength. Statistical analyses included t-tests, Welch tests, Pearson correlations, mixed-linear, and nonlinear regression analyses. Positive correlations with absolute trunk strength were found in subjects without obesity for all anthropometric parameters except WHtR. Weaker positive and partly negative correlation and linear regression coefficients were found in subjects with obesity. Nonlinear relationships were found between age, BMI, WHtR, and absolute respective body weight-adapted trunk strength. The relationship between obesity-defining measures/ indices and trunk strength is non-linear. Increasing BMI, waist circumference, or WHtR above cut-off values known from cardiovascular research is linked to a decrease or weaker increase in trunk strength. Body weight adaptation is recommended to avoid misinterpretation of apparently good absolute trunk strength values in people with obesity.

Fluvio‐hydrological characteristics and diverse bedrock geology control the dynamic growth, truncation, and amalgamation of bedrock streambed and marine potholes

AbstractA total of 393 potholes (368 fluvial and 25 marine potholes) were studied at seven different sites in both the fluvial and marine environments. Diverse bedrock properties and large‐scale delivery of tools and grinders regulate the dynamic growth, truncation, and amalgamation of potholes. Therefore, the principal objectives of the study are (i) to examine the relationship between the growth of potholes and substrate lithological with structural characteristics (applying geospatial and Schmidt hammer for rock strength analysis) and (ii) to measure the morphology, and size of tools and grinders, processes of truncation and amalgamation in hydro‐geomorphic environment using various indices and field techniques. The result showed that large potholes are stretched in the direction of lineament axes and roughly parallel to the river flow direction. Here, the steady growth of pothole depth‐diameter is controlled by active bedrock structures, tools, or grinders, and monsoonal high‐velocity bank full discharge. Consequently, the deepening and widening of potholes are relatively slow at Bindu, Deuli, and marine beach Neil Island due to fewer structures and little supply of tools or grinders. In small stretches, (Damodar, Subarnarekha, and Rarhu) canyons and gorge‐like features (bedrock incision) are formed at Rajrappa, Bhakuyadi, and Guridih sites due to cyclic truncation and amalgamation. Truncation and amalgamation processes restrict the vertical depth threshold value of potholes within 3 m, particularly at Rajrappa, Bhakuyadi, and Guridih sites. Scientific study of the pothole's dynamic growth is greatly necessary for the different environmental engineering and river hydraulic projects like excavation, dredging, and dam or barrage construction. Successively, it is essential to compute the cost of rock excavation or dredging, primarily for the mechanical strength of the bedrock river channel and its stability.

Mechanical Strength and Mechanism Analysis of Silt Soil Cured by Straw Ash-Calcium Carbide Slag.

Large-scale engineering projects frequently involve pit excavation and wetland landfill operations, resulting in significant silt accumulation that occupies land and adversely affects the environment. Curing technology offers a solution for reusing this waste silt. In this study, straw ash and calcium carbide slag are proposed as effective curing agents for silt soil. Various indoor tests were conducted to evaluate the mechanical properties of the cured silt soil, while X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to analyze its mineral composition and micro-morphology. The results showed that increasing the curing agent dosage significantly improved soil strength. Specifically, at a 10% dosage, the California bearing ratio (CBR) value increased to 18.7%, which is 13.4 times higher than untreated silt soil and exceeds road specifications by 8%. At a 20% dosage, the unconfined compressive strength (UCS) value reached 1.38 MPa, meeting the ≥0.8 MPa requirement for roadbeds. Based on economic considerations, a 20% dosage of straw ash-calcium carbide slag was selected as optimal. Microscopic analysis revealed that the addition of these agents promoted the formation of hydrated calcium silicate, filling pores and enhancing the mechanical properties of the cured soil, resulting in a more dense and stable structure.

Interpretable Machine Learning Method for Compressive Strength Prediction and Analysis of Pure Fly Ash-based Geopolymer Concrete

Interpretable Machine Learning Method for Compressive Strength Prediction and Analysis of Pure Fly Ash-based Geopolymer Concrete

Supplemental Material for Posttraumatic Resilience and Growth: A Network Analysis of Character Strengths Among Sexual Assault Survivors

Supplemental Material for Posttraumatic Resilience and Growth: A Network Analysis of Character Strengths Among Sexual Assault Survivors

Ultimate Strength Analysis of Aluminium Honeycomb Sandwich Panels Subjected to Uniaxial Compressive Loads and Lateral Pressure

Ultimate strength is critical for hull structures because it determines the maximum load the structure can withstand before catastrophic failure. Aluminium honeycomb sandwich panels provide excellent energy absorption and a high strength-to-weight ratio. However, further investigation of honeycomb sandwich panel structural performance is needed in typical marine conditions. This study focuses on the numerical analysis of honeycomb sandwich panels employing the nonlinear finite element method through the commercial software ANSYS. It investigates their performance under uniaxial compression and varying lateral pressure conditions while considering different cell edge lengths and core height configurations. Several structural configurations are compared to the experimental work published in the literature. Enhanced by experimental accuracy, the present study is a further step in expanding the application of honeycomb sandwich panels for ship hull applications that may lead to light and energy-efficient structures.

Digital Image Correlation and Reliability-Based Methods for the Design of Structural Beams Made from Recycled Concrete Using Aggregates from Precast Rejects

The use of recycled aggregates in the manufacture of concrete is presented as a solution to reduce the consumption of resources and waste in the construction sector and contribute to a lower environmental impact. This work aims to explore the possibility of producing structural beams from recycled concrete using aggregates from precast concrete rejects and to improve their design using advanced characterisation techniques. To this end, the experimental data coming from mechanical test and the use of the digital image correlation approach are combined with a robust reliability-based method. The full-field data provided by the digital image correlation approach allow to determine the probabilistic density functions of the mechanical data. From these data, a predictive analysis of the maximum strength and deflection of flexural beams is carried out based on robust design techniques. This approach uses analytical theoretical models and a Monte Carlo-based simulation strategy that allows the prediction of the behaviour of the beams. This methodology was validated by manufacturing six beams with the previously analysed recycled concrete, HA-30, and testing them in the laboratory. All the beams showed behaviour within the predicted range: around 49.7 kN maximum load and just over 9.3 mm maximum deflection. These results demonstrate the robustness of the approach as well as the feasibility of using precast rejects for the manufacture of structural elements.

Strength Analysis and Optimization Recommendations for the Cargo Hold Sections of Ultra-Large Container Ships Based on an Improved High-Order Finite Element Method

Strength Analysis and Optimization Recommendations for the Cargo Hold Sections of Ultra-Large Container Ships Based on an Improved High-Order Finite Element Method

Artificial neural network modeling for mineralogical and strength analysis of clayey soils

Artificial neural network modeling for mineralogical and strength analysis of clayey soils

Investigation of the Effects of Thermal Cycling and Surface Treatments on Interim Resin Materials Produced with Additive Manufacturing

This study aimed to compare the impact of thermal cycling on the flexural strength (σfs) of 3-dimensional (3D) printer resins and polymethyl methacrylate (PMMA). It also aimed to evaluate different surface treatment protocols and surface sealant applications on the surface roughness (Ra) and surface hardness (VHN) of the resins used. Rectangular (25�2�2 mm) and disc (Ø10�2-mm) specimens were fabricated from auto-polymerized PMMA, and 3D-printed resins were tested for mechanical properties (ISO 10477) using thermal cycling (n=10). Disc specimens were separated into three groups (n=10) based on the surface treatments: conventional sanding (C), disk polishing (P), and surface sealant coating (O). Ra and VHN values were statistically analyzed with the Kolmogorov Smirnov, Shapiro Wilk, Independent Samples t-test, Mann-Whitney test, one-way ANOVA test and Kruskal Wallis test (α =.05). A significant main effect was found on the flexural strength analysis for each of the two factors: thermal cycling procedure (p[0.001) and materials (p 0.001). A significant main effect was found on the surface roughness and hardness analysis for each of the two factors: surface treatment protocols (p[0.001) and materials (p[0.001). Based on the results; interim materials produced with 3D-printed resins have better mechanical properties than conventionally polymerized materials. Coated materials had lower surface roughness values than polished ones, and adding a surface sealant agent increased their hardness significantly.

Photobiomodulation in carpal tunnel syndrome with pain, strength, and functionality analysis: a systematic review and meta-analysis.

Carpal tunnel syndrome (CTS) is characterized as a compressive neuropathy of the median nerve and has several treatments, including photobiomodulation, which can be performed with low-intensity laser therapy (LLLT) and light-emitting diodes (LEDs). To carry out a literature review on the effectiveness of low-intensity laser therapy (LLLT) in CTS. This study is characterized by being a systematic review with metaanalysis. The databases included were PubMed, Embase, Cochrane, the Physiotherapy Evidence Database (PEDro), Scopus and LILACS. Also, gray literature: Google Scholar, OpenGrey and CAPES Theses and DissertationsCatalog. The search was carried out in all databases on October 11, 2023 and updated on June 06, 2024. The risk of bias was assessed using the Cochrane tool, RoB 2, by two blinded reviewers and conflicts were resolved by consensus. The outcomes of interest were pain intensity (Visual analogue scale), strength (handgrip and pinch) and hand functionality (Boston questionnaire, Levine questionnaire, Purdue Pergboard Test). Statistical analysis was carried out using RevMan 5.4.1. Continuous results were expressed as standard mean differences (95% CI), with p-value of < 0.05 considered statistically significant. The value of the I2 statistical test was calculated to test for heterogeneity between studies. A random effects model was adopted. 13 randomized controlled trials were selected from 1.613 records. In the general bias analysis, two studies (15,4%) were considered to have some relevant problems that could interfere with the quality of the study, and three (23,1%) were identified as having a high risk of bias, eight studies (61,5%) were classified as having a low risk of bias. In the meta-analysis, it was possible to observe that there were no advantages of the laser for pain (p = 0.08), nor for handgrip strength (p = 0.11), but it did produce improvements in functionality. It is concluded that LLLT is an effective therapeutic modality in the treatment of CTS, improving functionality; however, despite the studies pointing to advantages for the modality in reducing pain and improving grip strength, the meta-analysis did not show this result. Even so, there is a need for more clinical trials are needed to standardize dosimetry, mainly because the primary studies showed clinical advantages of PBM. Open Science Framework (OSF)- https://doi.org/10.17605/OSF.IO/HQCRP .

Village Development through Potential Analysis of Kaliagung Village, Kapanewon Sentolo, Kulon Progo Regency, Special Region of Yogyakarta

This study aims to determine the potential of Kaliagung Kapanewon Sentolo Village, Kulon Progo Regency, Special Region, it is hoped that with the identification of this, the researcher can formulate a roadmap for the development of Kaliagung Kapanewon Sentolo Village, Kulon Progo Regency, Special Region of Yogyakarta. This research is a qualitative descriptive research. The population in this study is the leaders and community leaders of all community members in Kaliagung Village, Kapanewon Sentolo, Kulon Progo Regency, Special Region of Yogyakarta. The data collection method uses observation, focus discussion groups and literature studies are used to obtain information about the potential of the village, qualitative descriptive analysis specifically using the analysis of strengths, weaknesses, opportunities, and threats. SWOT analysis contributes to the development of strategic management theory, especially in the context of independent village development. The SWOT analysis shows that this framework can be applied effectively in the context of village development. This approach helps to link between internal conditions (local resources) and external conditions (government and market support) in the formulation of development strategies. The results of the EFE and IFE analysis placed the Kaliagung Village in a certain quadrant, which provided a theoretical basis for choosing the most suitable strategy, such as a growth-oriented strategy .

Effects of Post-Fire Rehydration on the Mechanical Properties of Slag-Modified Concrete

Although previous research has examined the mechanical properties of concrete exposed to high temperatures, further investigation is needed into the effects of post-fire curing on the recovery of strength and stiffness of sustainable concretes produced with slag-modified cement. This study conducted an experimental analysis of the residual compressive strength and modulus of elasticity of different types of concrete (20 MPa or 30 MPa) exposed to varying maximum temperature levels (200 °C, 400 °C, 600 °C, 800 °C) and post-fire treatments (with or without rehydration). The concrete specimens were produced using Portland cement CP II-E-32. The rehydration method involved one day of water curing, followed by 14 days of air curing. Statistical analyses revealed potential improvements in the mechanical properties of concretes produced with slag-modified cement due to rehydration processes after exposure to different temperatures levels. The highest values of the relative residual strength factor (Φc) were observed in specimens exposed to a maximum temperature of 600 °C, ranging from 0.862 to 0.905. The highest values of the relative residual elastic modulus factor (ψc) were verified for a maximum temperature of 200 °C, ranging from 0.720 to 0.778. The experimental results were compared with strength and stiffness predictions of design codes. The inclusion of slag in concrete reduced microcracking during the rehydration process due to the reduced amount of calcium hydroxide in the cementitious matrix, increasing the concrete’s relative residual strength and stiffness after post-fire curing.

An approach on sustainable leather production system and method: Chromium tanning in vacuum operated reaction vessel for sheepskins

Conventional leather chromium tanning requires long process time, excessive water usage and results in low float exhaustion of chrome salts. Our study aimed to eliminate the negative aspects of chromium tanning by designing a vacuum operated reaction vessel/drum and suitable production recipe for sheepskins. Tanning time decreased from 10 h to 6 h under vacuum. Float uptake was increased almost 30% according to the chrome oxide (Cr2O3) contents in leather and residual floats. Using the process water was also considerably saved. Process success was proved with Cr2O3 contents in leather and wastewater by chemical analyses after tanning operations. Shrinkage temperature (Ts) controls as hydrothermal stability indicator of collagen were also realized on the tanned skins. Pollution loads of conventional and vacuum operated chromium tanning were discussed with chemical oxygen demand (COD), total suspended solids (TSS), conductivity and salinity in the tanning baths. Physico-mechanical properties were also compared of the final products by tensile strength and tear load analyses. The results showed that vacuum operated chromium tanning was highly effective and promised for the sustainable production of leather products.

Strength Analysis and Reinforcement of 120 m3 Liquid Helium Storage Tank for Transportation Case

To ensure the safe transportation of a 120 m3 liquid hel ium storage tank, based on the analysis of its structure, material, and load characteristics, a finite element model for stress and strength analysis is established and solved by using the coupled thermo-mechanical analysis method for the accelerating and cornering cases experienced by the tank during transportation. The stress and deformation distributions in different transportation cases are analyzed in comparison to the finite element model, and the strength check is carried out for the tank. The study shows that under various working cases, the extreme value of stress of some parts is 267.5 MPa; this does not satisfy the strength requirement, and therefore requires structural reinforcement. The analysis of the reinforcing effect of the reinforcement structure shows that the stress extremes of the dangerous parts of the tanks after reinforcement decreased by 63.7% and 34.7%; the structural strength meets the standard requirements, and the new reinforcement structure only leads to an increase of 6% in the liquid nitrogen consumption of the cold screen, which is a better reinforcing effect.

Strength and fatigue analysis of mudline wellhead and its tie-back system in offshore drilling

This article presents a new operational approach for mudline wellheads, aimed at transforming exploration wells into development wells, thus reducing costs and construction time in marginal oil fields. It includes a fatigue life analysis of mudline wellhead systems and tie-back systems at different platform heights (20 m and 100 m). The study develops mechanical models to assess structural integrity under environmental loads such as wind, waves, and currents. Stress concentrations, especially at connection points, are analyzed to determine fatigue life. The study not only establishes the service life for both water depth scenarios but also offers structural optimization suggestions for the tie-back system. Incorporating marine environmental data, it provides a comprehensive strength and fatigue analysis, ensuring the structural safety of the mudline wellhead and tie-back system. This research underpins the economic viability of the mudline wellhead tie-back operation mode, contributing significantly to offshore drilling design, efficiency, and sustainability, marking progress in offshore engineering.

Complexities of riverfront development for the hilly city of Paonta Sahib in India.

The rapid urbanization, industrial growth, and socio-cultural activities along riverbanks in hilly cities are transforming land use and intensifying water infrastructure challenges. Paonta Sahib, a culturally significant town in Himachal Pradesh on the Yamuna River, along the foothills of the Himalayas exemplifies these pressures due to its religious tourism, industrialization, and mining activities. This study explores sustainable riverfront development at Paonta Sahib, addressing socio-cultural, environmental, and technical concerns essential for eco-sensitive urban planning. A Strength, Weakness, Opportunity and Threat (SWOT) analysis highlights strengths such as Paonta Sahib's strong cultural identity and economic potential, alongside weaknesses like limited water infrastructure and unregulated land use. Opportunities for eco-sensitive zoning and circular economy practices are proposed as strategies to mitigate environmental impacts, with financial projections indicating a 68 million INR annual cost recovery over a 35-year development period. Additionally, pollutant scenario analysis is recommended to support effective water quality management. Findings emphasize the importance of collaborative efforts between local authorities, technical experts, and communities to address the extreme hydrological, environmental, and planning challenges faced by riverbank cities. This balanced approach seeks to enhance Paonta Sahib's urban identity while preserving ecological integrity, offering a model for sustainable development in similar hilly settlements. The proposed framework aims to guide future policies for resilient riverfront urbanization, emphasizing adaptive planning, community engagement, and infrastructure that support both economic growth and environmental sustainability.