Minimum Weight Research Articles

Numerical and Experimental Evaluation of Structured Material for Use in Multiscale Topology Optimization

Multiscale topology optimization is a powerful tool for engineers seeking a design with minimum weight and maximum stiffness, using a structured material in the form of a lattice structure. Furthermore, the current trend is to combine multiple lattice topologies in one component to achieve the best possible response to local loading conditions while minimizing weight. Therefore, herein, a numerical and experimental evaluation by compression tests in two directions is performed for six basic lattice topologies and two hypotheses are tested. The first hypothesis states that an additional weight saving of more than 30% can be achieved by a better choice of lattice topology. The second hypothesis is based on the manufacturing limitations of the laser powder bed fusion technology and the assumption that a favorable loading direction parallel to the building direction exists. The first hypothesis is only confirmed for loading in the direction parallel to the building direction and the second only for two lattice topologies. When both hypotheses are combined, the additional weight reduction of the multiscale topology optimization result is 44.5% according to the numerical results and 32.7% according to the experimental verification.

Optimizing Agronomic Practices for Aerobic Rice under Calcareous Soil in Bihar

Three experiments were conducted during 2014-19 at Pusa (Samastipur), Bihar, to develop agronomic practices for aerobic rice with respect to the performance of varieties at different dates of sowing, optimizing seed rate and spacing, and nitrogen requirement and its scheduling under the calcareous soil of North Bihar plains. Sowing during the first week of June resulted in significantly higher yield attributes and grain yield. Among varieties, Abhishek recorded significantly higher grain yield except for the hybrid. Weather variables during different growth phases significantly influenced the yield. The hybrid outyielded all the test varieties. Maximum grain and straw yields were recorded with 20 cm spacing and a 35 kg/ha seed rate. Also, the minimum dry weight of weeds was recorded with this spacing and seed rate. Nitrogen at 140 kg/ha in three or four splits along with brown manuring resulted in significantly higher grain and straw yields. Also, the maximum uptake of NPK and B:C ratio was recorded with this treatment.

Permanent epicardial pacing : a first line strategy in children

Abstract Background Permanent cardiac pacing in paediatric patients remains a challenge. According to the European Paediatric and Congenital Society (AEPC) recommendations, below 20 kg epicardial implantation is preferred, while above 20 kg endocardial implantation is given priority unless specific contraindication. In the literature, a weight at 15 kg is also found to be the minimal weight above which an endovascular implantation is considered. However, endovascular systems have been reported to be associated with a high risk of complications. Recent improvements in epicardial leads technology have significantly improved pacing thresholds (1-3), battery life and reduced the risk of re-intervention for epicardial lead dysfunction (4,5). Purpose The aim of the study is to evaluate the long-term results and efficacy of epicardial pacing in children and to investigate risk factors for epicardial lead dysfunction. Method We performed a retrospective, single-centre analysis of consecutive patients aged ˂18 years implanted with an epicardial PM between 2004 and 2020. The data collection included initial pacing parameters, at 1 month, 1 year, 2 years, and at last follow-up, as well as occurrence of early and late complications. Results A total of 101 patients (93 atrial and 131 ventricular epicardial) were analysed. The mean follow-up time was 6.2 years (range 2 days to 16.9 years). Median age at implantation was 4.2 years (IQ 0.3-8.8 years), median weight was 15.2 kg (IQ 5.2-28.0 kg). Congenital heart disease (CHD) was recorded in 59,4% of patients. Reasons for implantation were postoperative complete atrioventricular block (AVB) (40.6%), congenital AVB (37.6%), sinus dysfunction (7.9%), complete AVB with heart disease without surgery (7.9%), others (4%). Four patients had a system infection resulting in device extraction and reimplantation. The mortality rate was 15.8%, but no deaths was directly related to PM implantation or dysfunction. Detection values, impedances were stable over time, and the and average pacing thresholds remained ˂0,98±0,81 volt in the atrium and ˂ 1.57±0,89 volt in the ventricle. Lead survival was 96,7%, 90,7%, 82,3%, 74,5% at 1, 5, 8 and 10 years. The presence of CHD, weight ˂15kg, dual chamber implantation, implantation for postoperative BAV were not significant risk factors for lead dysfunction. In the group of patients implanted above 15kg the presence of a CHD significantly increased the risk of lead dysfunction (p=0.037) and all-cause reimplantation (p=0.010). In the group implanted above 15kg without any cardiopathy, the survival rate without lead dysfunction at 5 and 10 years was 100% and 90.9% respectively. Conclusion Epicardial pacing in children with steroid-eluting leads shows good long-term results with stable pacing parameters and good survival from lead dysfunction. For children implanted at a weight above 15 kg and without cardiopathy results with epicardial stimulation were excellent.Epicardial lead survival

Effect of Different Level of Chitosan and Beeswax Edible Coating on Storage Life and Physio-Chemical Properties of Strawberry (Fragaria × ananassa) cv Winter Dawn

The present investigation was done to understand the effect of different edible coating on increasing the shelf-life of strawberry at room temperature. Postharvest losses in fruits are a serious problem due to rapid deterioration during storage. Use of edible coatings over fruits is used to improve their quality and enhance the shelf life. The main purpose of this study was to assess the effect of Chitosan and beeswax coating in extending the shelf-life of strawberry including physio -chemical changes at room temperature. The experiment was laid out in completely randomized design (CRD) with 10 treatments and 3 replications. The treatment consisted of coating material with Chitosan (1.5g%), Chitosan +TPP (1.5g+0.5g%), Chitosan +TPP (1.5g+1%), beeswax (5g), beeswax + TPP (5G+1.5%), Chitosan+ beeswax (0.75g+ 2.5g), Chitosan+ beeswax +TPP(0.75g+2.5g+0.5%), Chitosan+ beeswax +TPP (0.75g+2.5g+1%). Statistical analysis revealed that the treatment chitosan 1.5g+ TPP 1% had the minimum Weight loss 0.08g, while having the maximum amount of Vitamin C 38.45mg/100g, Hardness 8.07 kg/inch2, Bulk Density 1.9g/cm3 and TSS 5.13°Bx. However, Chitosan 1.5g+TPP 0.5% showed maximum Reducing sugar 3.73% and non-reducing sugar 0.92%. While chitosan 0.75g+ beeswax 2.5g+TPP 0.5g have the maximum Total sugar 5.23%.

Effect of PASLoc Meals on the Zootechnical and Nutritional Parameters of Young Wistar Rats Suffering from Induced Moderate Acute Malnutrition

Aims: The objective of this study was to assess the efficacy of four food products manufactured from locally sourced ingredients in restoring Wistar rats afflicted with induced moderate acute malnutrition. Study Design: The rats used in this research were kept in separate metabolic cages with wire mesh flooring. Place and Duration of Study: The study was conducted at the vivarium of the Ecole Normale Supérieure in Abidjan, Côte d'Ivoire, over a period of 38 days. Methodology: 42 male rats, with an average age of 80 ±5 days and an average weight of 103.46 ±5.10 g, were randomly divided into six batches of seven rats each. Two control batches (MID and PCD) and four experimental batches (PASLoc1A, PASLoc1B, PASLoc2A, and PASLoc2B) were formed. The experiment consisted of an adaptation phase (5 days), a malnutrition induction phase (19 days), and a nutritional rehabilitation phase (14 days). Zootechnical and nutritional parameters were assessed at the end of the induction and nutritional rehabilitation phases. Results: Malnourished animals experienced a body weight loss rate of -22.36 ±6.47%, leading to a decline in all zootechnical parameters, including weight gain (1.39 ±0.28 g/day), body length (0.95 ±0.64 cm), and feed efficiency coefficient (-24.98 ±5.47). The nutritional rehabilitation phase resulted in the correction of the dysfunctions observed during induction, especially in terms of body weight gain, with rates comprised between 20.84 ±5.03% and 34.59 ±3.33%. The minimum weight gain for the rats fed PASLoc diet was 1.66 ±0.54 g/d for Pasloc1B, respectively. PASLoc diets have a significant impact on nutritional value, with a minimum biological value of 94.04 ±0.25%. Conclusion: The result of this study suggest that PASLoc2A and PASLoc2B possess a robust nutritional potential, and their consumption can effectively address issues of moderate acute malnutrition after weaning.

Pigeonhole Design: Balancing Sequential Experiments from an Online Matching Perspective

Practitioners and academics have long appreciated the benefits of covariate balancing when they conduct randomized experiments. For web-facing firms running online A/B tests, however, it still remains challenging in balancing covariate information when experimental subjects arrive sequentially. In this paper, we study an online experimental design problem, which we refer to as the online blocking problem. In this problem, experimental subjects with heterogeneous covariate information arrive sequentially and must be immediately assigned into either the control or the treated group. The objective is to minimize the total discrepancy, which is defined as the minimum weight perfect matching between the two groups. To solve this problem, we propose a randomized design of experiment, which we refer to as the pigeonhole design. The pigeonhole design first partitions the covariate space into smaller spaces, which we refer to as pigeonholes, and then, when the experimental subjects arrive at each pigeonhole, balances the number of control and treated subjects for each pigeonhole. We analyze the theoretical performance of the pigeonhole design and show its effectiveness by comparing against two well-known benchmark designs: the matched-pair design and the completely randomized design. We identify scenarios when the pigeonhole design demonstrates more benefits over the benchmark design. To conclude, we conduct extensive simulations using Yahoo! data to show a 10.2% reduction in variance if we use the pigeonhole design to estimate the average treatment effect. This paper was accepted by George Shanthikumar, data science. Supplemental Material: The online appendix and data files are available at https://doi.org/10.1287/mnsc.2023.02184 .

A method for constructing quaternary Hermitian self-dual codes and an application to quantum codes

AbstractWe introduce quaternary modified four $$\mu $$ μ -circulant codes as a modification of four circulant codes. We give basic properties of quaternary modified four $$\mu $$ μ -circulant Hermitian self-dual codes. We also construct quaternary modified four $$\mu $$ μ -circulant Hermitian self-dual codes having large minimum weights. Two quaternary Hermitian self-dual [56, 28, 16] codes are constructed for the first time. These codes improve the previously known lower bound on the largest minimum weight among all quaternary (linear) [56, 28] codes. In addition, these codes imply the existence of a quantum [[56, 0, 16]] code.

Modelling the mechanical properties of concrete produced with polycarbonate waste ash by machine learning

India’s cement industry is the second largest in the world, generating 6.9% of the global cement output. Polycarbonate waste ash is a major problem in India and around the globe. Approximately 370,000 tons of scientific waste are generated annually from fitness care facilities in India. Polycarbonate waste helps reduce the environmental burden associated with disposal and decreases the need for new raw materials. The primary variable in this study is the quantity of polycarbonate waste ash (5, 10, 15, 20 and 25% of the weight of cement), partial replacement of cement, water-cement ratio and aggregates. The mechanical properties, such as compressive strength, split tensile strength and flexural test results, of the mixtures with the polycarbonate waste ash were superior at 7, 14 and 28 days compared to those of the control mix. The water absorption rate is less than that of standard concrete. Compared with those of conventional concrete, polycarbonate waste concrete mixtures undergo minimal weight loss under acid curing conditions. Polycarbonate waste is utilized in the construction industry to reduce pollution and improve the economy. This study further simulated the strength characteristics of concrete made with waste polycarbonate ash using least absolute shrinkage and selection operator regression and decision trees. Cement, polycarbonate waste, slump, water absorption, and the ratio of water to cement were the main components that were considered input variables. The suggested decision tree model was successful with unparalleled predictive accuracy across important metrics. Its outstanding predictive ability for split tensile strength (R2 = 0.879403), flexural strength (R2 = 0.91197), and compressive strength (R2 = 0.853683) confirmed that this method was the preferred choice for these strength predictions.

Body mass assessment of male soldiers of the Armed Forces of Ukraine

Body weight control of male soldiers of the Armed Forces of Ukraine is not only about ensuring their somatic (physical) health. It is also the choice of proper nutrition, neat appearance, successful passing physical training tests, high work capacity and timely performance of military duties. Moreover, it is also the presence of special criteria – norms (standards), the development of which has unreasonably little attention in the past in the Armed Forces of Ukraine, but in the current conditions they are extremely relevant. Excessive body weight, and especially obesity, reduces a person’s work capacity, complicates intellectual and physical activity, causes disability, premature aging and shortened life expectancy. Body weight standards should be universal enough to take into account as much as possible departmental interests, in particular the military, and to cover individual characteristics of human development, such as height, age, and body constitution. The purpose of the study is to improve body weight assessment system of male servicemen of the Armed Forces of Ukraine with different height, age and body constitution. Methods of the study are as following: theoretical analysis and generalization; extrapolation; method of least squares; regression analysis. Material: according to the authors’ formula of optimal body weight for men of different height, age and different body constitution, the limits of body weight norms for nine age groups were obtained in accordance with the requirements of physical training standards. Results: a table of minimum and maximum body weight for servicemen of different heights depending on the age group was developed. A methodology for assessing the body weight of military personnel, taking into account their body constitution, has been developed. Conclusions. To estimate the body weight of male servicemen of the Armed Forces of Ukraine, a table has been developed within the height range from 1.50 to 2.06 m in nine age groups from 18 to 60 years and older for soldiers with different body constitutions. In the case when body weight of male servicemen of the Armed Forces of Ukraine exceeds the table requirements, it is necessary to obtain the percentage of its deviation from the optimal body weight for men of different height, age and different body constitution, which is calculated according to the formula: Optimal body weight for men = (4.7619 × wrist circumference – 90.4762) × (0/08135×age+21.6916) × L2 / 100+(0.08135 × age + 21.6916) × L2 . If the body weight differs from the optimal body weight for men by no more than ±10%, then it meets the requirements of the norm.

The optimal design of composite overwrapped pressure vessels based on geodesic dome trajectories using population-based techniques

Pressure vessels are frequently fabricated using composite materials which stand out with their high strength-to-weight ratio, and provide considerable advantages compared to conventional steel ones. In our previous study, the impacts of Polar Opening Radius (POR) on the mechanical characteristics of Composite Overwrapped Pressure Vessels COPVs were numerically examined, and it was determined that effective volume and structural weight responses improved with higher POR, but significant deterioration took place in first-ply interlaminar shear stress (ILSS) responses after 20 mm POR. Therefore, to achieve the best possible mechanical and structural behaviors, the present study aimed to discover an optimum POR that provides maximum internal volume as well as minimum weight and ILSS responses. In this regard, the optimum geodesic dome trajectory based on the 10–30 mm POR range was determined using the Bees Algorithm (BA) and the Particle Swarm Optimization (PSO). According to the findings, the optimum POR was found as 17.9643 and 17.9671 mm due to the BA and PSO algorithms, respectively. Moreover, first-ply ILSS, structural weight and effective internal volume for the optimal COPVs design were achieved as 52.444 MPa, 1070.81 g, and 2721.94 cm3 from the BA, and thus COPVs with maximum strength and minimum structural weight has been designed. In this way, thanks to the optimization studies, an approximately 18.31% improvement in ILSS responses was achieved despite the negligible deterioration in weight and volume compared to the COPVs with a 30 mm POR.

Multidisciplinary analysis and structural optimization for the aeroelastic sizing of a UAV wing using open-source code integration

PurposeThis paper aims to propose a structural sizing approach of an unmanned aerial vehicle (UAV) wing that takes into account the aeroelasticity effects through a fluid–structure interaction analysis.Design/methodology/approachThe sizing approach proposed in this study is an iterative process, each iteration of which consists of two sub-loops, a multidisciplinary analysis (MDA) loop followed by a structural optimization loop. The MDA loop seeks the aeroelastic equilibrium between aerodynamic forces and structural displacements using a fixed-point iteration scheme. Once the equilibrium is reached, the converged pressure loads are used for the structural optimization, which aims to find the structural thicknesses that minimize the wing weight under failure criteria. The two sub-loops are run sequentially in an iterative process until the mass is converged. The analysis models are implemented in open-source software, namely, PANUKL for aerodynamics and MYSTRAN for structures, while the whole process is automated with Python and integrated in the open-source optimization framework OpenMDAO.FindingsThe approach was applied to the design of the Predator MQ-1 wing. The results of the MDAs show the convergence of the wing deformations to the flight shape after few iterations. At the end of the aeroelastic sizing loop, the result is a structurally sized wing with minimal weight considering the aeroelasticity effects.Originality/valueThe approach proposed takes into account the wing aero-structural coupling effects while sizing its structure instead of a fixed load distribution. In addition, the approach is fully based on open-source codes, which are freely available for public use and can be fully reproducible.

SEMG-based automatic characterization of swallowed materials

Monitoring of ingestive activities is critically important for managing the health and wellness of individuals with various health conditions, including the elderly, diabetics, and individuals seeking better weight control. Monitoring swallowing events can be an ideal surrogate for developing streamlined methods for effective monitoring and quantification of eating or drinking events. Swallowing is an essential process for maintaining life. This seemingly simple process is the result of coordinated actions of several muscles and nerves in a complex fashion. In this study, we introduce automated methods for the detection and quantification of various eating and drinking activities. Wireless surface electromyography (sEMG) was used to detect chewing and swallowing from sEMG signals obtained from the sternocleidomastoid muscle, in addition to signals obtained from a wrist-mounted IMU sensor. A total of 4675 swallows were collected from 55 participants in the study. Multiple methods were employed to estimate bolus volumes in the case of fluid intake, including regression and classification models. Among the tested models, neural networks-based regression achieved an R2 of 0.88 and a root mean squared error of 0.2 (minimum bolus volume was 10 ml). Convolutional neural networks-based classification (when considering each bolus volume as a separate class) achieved an accuracy of over 99% using random cross-validation and around 66% using cross-subject validation. Multiple classification methods were also used for solid bolus type detection, including SVM and decision trees (DT), which achieved an accuracy above 99% with random validation and above 94% in cross-subject validation. Finally, regression models with both random and cross-subject validation were used for estimating the solid bolus volume with an R2 value that approached 1 and root mean squared error values as low as 0.00037 (minimum solid bolus weight was 3 gm). These reported results lay the foundation for a cost-effective and non-invasive method for monitoring swallowing activities which can be extremely beneficial in managing various chronic health conditions, such as diabetes and obesity.

Parameterization of Maxwell - Cremona Diagram for Determining Forces in Elements of a Scissors Truss

An analysis of changing patterns of the values of member forces in a scissors truss, depending on the position of connections of its lower chords to the upper chords, is performed. Exploring effective truss structure designs in terms of balanced combination of maximum strength and minimum weight is a sustainable approach to a more rational use of building materials and the development of green construction. This determines the relevance of this area of research. The analysis of configurations of the truss under study was performed using the parameterized Maxwell - Cremona diagram. Such diagram is a visually informative tool in presenting the calculation results and it fully reflects the relationship between the member forces and the parameters of the structure. The research process was performed using the MS Excel spreadsheet editor. This eventually developed into a software tool for finding effective scissors truss designs, which has full potential for further improvement and development. Thus, the functionality of the tool can be easily expanded to designing scissors trusses made of various structural materials, as well as with various crosssectional shapes of its elements. The proposed approach to the calculation of such structures can serve as a basis for parameterization of trusses with other types of web.

Development of a heavy vehicle torque rod applying continuous fiber reinforced thermoplastic composite materials instead of forged steel material: Design, analysis and optimization

The torque rod is an important component of the suspension system that connects the axle to the chassis in heavy commercial vehicles. The main motivation of this study is the development of a torque rod made of (1) plus cross-section, (2) continuous carbon and glass fiber reinforced hybrid thermoplastic composites, which can replace a forged steel torque rod used in heavy vehicles, has superior mechanical properties, provides minimum cost and weight. This study aims to develop a torque rod before its production within the framework of integration with Computer Aided Design (CAD), Finite Element Analysis (FEA), and Multi-Criteria Decision Making (MCDM). In this study, the design data and the properties of the composite materials were chosen as control factors. The minimum displacement, the best mechanical properties such as tensile stress, compressive stress, torsional shear stress, maximum critical buckling load, and the minimum part weight minimum production cost per piece were selected as quality characteristics. As a result of the FEA study, considering the experimental set of the Taguchi Method L25 orthogonal array, the data on mechanical properties, weight, and production cost per piece were subjected to the MCDM process using the Entropy Weighted TOPSIS method. As a result of the MCDM study, a torque rod made of continuous fiber-reinforced thermoplastic composite material, instead of a torque rod produced by forged steel, had the highest mechanical properties produced, the weight of the torque rod can be reduced by 64.76%, and the production costs per piece can be reduced by 37.5%. This study’s findings have shown that the torque rod produced from continuous fiber-reinforced thermoplastic composite materials in a new geometry with a plus cross-section can be substituted for the torque rod produced by steel forging. Thus, it will contribute to reducing the fixed vehicle weight, especially in heavy commercial vehicles, reducing CO2 emissions, and increasing the range of the vehicles.

Pre-Operative Characteristics Helping to Avoid Gastrostomy Tube After Mandibular Distraction in Neonates With Pierre-Robin Sequence: A Institutional Case-Series and Review of the Literature.

to investigate the ability of mandibular distraction osteogenesis (MDO) to avoid gastrostomy tube (G-tube). PubMed, EBSCOhost, Cochrane, and Embase. We retrospectively reviewed the number of MDO cases performed at our institution for patients with Robin Sequence (RS) over the past 10 years. In our institutional review, patients were excluded if they had a G-tube already placed at the time of surgery. We also performed a systematic review of the literature. Articles were excluded if they did not detail feeding outcomes after MDO, or if MDO was performed on patients that did not have RS. In our systematic review, 12 articles were included that comprised a total of 209 neonates with RS that underwent MDO. A total of 174 (83.3%) patients avoided a G-tube once MDO was performed. A total of 14 patients met the inclusion criteria at our institution. Of the 14 RS patients, 9 (64%) avoided having a G-tube placed and all (14/14) avoided tracheostomy. The average birth weight of patients avoiding a G-tube was 3.11 kg compared to 2.25 kg (P = .045) in the group requiring a G-tube. In the group avoiding a G-tube, the average weight at time of operation was 3.46 kg compared to 2.83 kg (P = .037) in the group requiring a G-tube. MDO may be considered as a surgical option to prevent G-tube placement for neonates with non-syndromic RS who have difficulty with PO feeding but whose airway obstruction is not severe enough to require respiratory support. Based on our institutional experience, a minimum weight of 3.00 kg correlated with higher success rates of PO intake and avoiding a G-tube.

Rational design of the aerodynamic rudder structure taking into account strength, rigidity and aeroelastic stability

The paper considers a design process of an aerodynamic rudder, which structure comprises the skin of constant thickness, a load-bearing structure and a trimmed nose that plays the role of an anti-flutter balancer. The aim of the work is to set and solve the design problem of a rational structural and technological solution of the rudder that meets the requirements of strength, rigidity, aeroelastic stability and minimum mass. To solve this problem, a design algorithm for the rudder, using topological and parametric optimization, is proposed. The main parameters of the design area and the trimmed nose required for topological optimization are determined. The ANSYS Workbench software package was used for the finite element analysis and topological optimization. Based on the results of optimization, post-processing was carried out. A structural and technological solution, that combines structural layouts with constant and variable width of the trimmed nose, was proposed. An analysis of the stress-strain state was carried out, and it was found that the designed structure meets the strength requirements for the given design case. A scheme for solving the parametric optimization problem of the rudder under the condition of aeroelastic stability is proposed. Within the framework of solving this problem, a flutter study was conducted, using a multi-mode model, which makes it possible to study the rudder and body-rudder flutter forms of an unmanned aerial vehicle (UAV) equipped with aerodynamic rudders. The results of the flutter study for the design mode of the UAV flight are obtained in the form of dependencies of the critical flutter velocity and frequency on the average width of the trimmed nose. The analysis of these dependencies allowed us to derive the optimal values of the trimmed nose parameters from the minimum weight condition for two rudder configurations: with a constant and variable width of the trimmed nose.

Solution of engineering design and truss topology problems with improved forensic-based investigation algorithm based on dynamic oppositional based learning

AbstractThe forensic-based investigation (FBI) is a metaheuristic algorithm inspired by the criminal investigation process. The collaborative efforts of the investigation and pursuit teams demonstrate the FBI’s involvement during the exploitation and exploration phases. When choosing the promising population, the FBI algorithm’s population selection technique focuses on the same region. This research aims to propose a dynamic population selection method for the original FBI and thereby enhance its convergence performance. To achieve this objective, the FBI may employ dynamic oppositional learning (DOL), a dynamic version of the oppositional learning methodology, to dynamically navigate to local minima in various locations. Therefore, the proposed advanced method is named DOLFBI. The performance of DOLFBI on the CEC2019 and CEC2022 benchmark functions is evaluated by comparing it with several other popular metaheuristics in the literature. As a result, DOLFBI yielded the lowest fitness value in 18 of 22 benchmark problems. Furthermore, DOLFBI has shown promising results in solving real-world engineering problems. It can be argued that DOLFBI exhibits the best convergence performance in cantilever beam design, speed reducer, and tension/compression problems. DOLFBI is often utilized in truss engineering difficulties to determine the minimal weight. Its success is comparable to other competitive MAs in the literature. The Wilcoxon signed-rank and Friedman rank tests further confirmed the study’s stability. Convergence and trajectory analyses validate the superior convergence concept of the proposed method. When the proposed study is compared to essential and enhanced MAs, the results show that DOLFBI has a competitive framework for addressing complex optimization problems due to its robust convergence ability compared to other optimization techniques. As a result, DOLFBI is expected to achieve significant success in various optimization challenges, feature selection, and other complex engineering or real-world problems.

The effects of dietary macronutrient composition on resting energy expenditure following active weight loss: A systematic review and meta-analysis.

A systematic review and meta-analysis was conducted to evaluate the relative effectiveness of different dietary macronutrient patterns on changes in resting energy expenditure (REE) in relation to weight loss, categorized as minimal (<5%) and moderate to high (>5%). Changes in REE were assessed using a DerSimonian and Laird random-effects meta-analysis. A diet lower in carbohydrates (CHO) or higher in fat and protein was associated with smaller reductions in REE, with these trends being more pronounced among participants who experienced moderate to high weight loss. Adjusted meta-regression analysis indicated that, within the participants who experienced moderate to high weight loss, each 1% increase in CHO intake was associated with a reduction of 2.30 kcal/day in REE (95% CI: -4.11 to -0.47, p = 0.013). In contrast, a 1% increase in protein and fat intake was correlated with an increase in REE by 3.00 (95% confidence interval [CI] [1.02, 5.07], p = 0.003) and 0.5 (95% CI [-2.43, 3.41], p = 0.740) kcal/day, respectively. No significant associations were found among participants who experienced minimal weight loss. These findings indicate that, under a caloric deficit, the impact of dietary macronutrient composition on REE may vary depending on the degree of weight loss and individual metabolic responses.

Isogeometric topology optimization of structures using the overweight approach

In this paper, a 2D isogeometric formulation of the material distribution for structural topology optimization considering minimum weight and local stress constraints using the overweight approach is proposed. The aim of this isogeometric formulation is to provide solutions with high spatial definition using a lower number of design variables in comparison with the formulations previously developed to define the material layout. Despite of this, an important number of local stress constraints has to be considered in the solution of the problem. For this purpose, an Overweight Constraint is used to consider all of them. The structural analysis is performed by means of the Isogeometric Analysis (IGA) and the distribution of material is modeled by means of quadratic B-splines. Moreover, the optimization is addressed by means of the Sequential Linear Programming algorithm (SLP) that is driven by the information provided by a full first-order sensitivity analysis extension of the IGA formulation. Finally, the proposed formulation is tested by means of some benchmark problems, and the results show that the isogeometric formulation provides solutions with high spatial definition. A comparison with a Finite Element Method (FEM) topology optimization formulation is included.

Factors Associated With High-Risk and Low-Risk Bone Stress Injury in Female Runners: Implications for Risk Factor Stratification and Management.

Bone stress injury (BSI) is a common overuse injury in active women. BSIs can be classified as high-risk (pelvis, sacrum, and femoral neck) or low-risk (tibia, fibula, and metatarsals). Risk factors for BSI include low energy availability, menstrual dysfunction, and poor bone health. Higher vertical load rates during running have been observed in women with a history of BSI. The purpose of this study was to characterize factors associated with BSI in a population of premenopausal women, comparing those with a history of high-risk or low-risk BSI with those with no history of BSI. It was hypothesized that women with a history of high-risk BSI would be more likely to exhibit lower bone mineral density (BMD) and related factors and less favorable bone microarchitecture compared with women with a history of low-risk BSI. In contrast, women with a history of low-risk BSI would have higher load rates. Cross-sectional study; Level of evidence, 3. Enrolled were 15 women with a history of high-risk BSI, 15 with a history of low-risk BSI, and 15 with no history of BSI. BMD for the whole body, hip, and spine was standardized using z scores on dual-energy x-ray absorptiometry. High-resolution peripheral quantitative computed tomography was used to quantify bone microarchitecture at the radius and distal tibia. Participants completed surveys characterizing factors that influence bone health-including sleep, menstrual history, and eating behaviors-utilizing the Eating Disorder Examination Questionnaire (EDE-Q). Each participant completed a biomechanical assessment using an instrumented treadmill to measure load rates before and after a run to exertion. Women with a history of high-risk BSI had lower spine z scores than those with low-risk BSI (-1.04 ± 0.76 vs -0.01 ± 1.15; P < .05). Women with a history of high-risk BSI, compared with low-risk BSI and no BSI, had the highest EDE-Q subscores for Shape Concern (1.46 ± 1.28 vs 0.76 ± 0.78 and 0.43 ± 0.43) and Eating Concern (0.55 ± 0.75 vs 0.16 ± 0.38 and 0.11 ± 0.21), as well as the greatest difference between minimum and maximum weight at current height (11.3 ± 5.4 vs 7.7 ± 2.9 and 7.6 ± 3.3 kg) (P < .05 for all). Women with a history of high-risk BSI were more likely than those with no history of BSI to sleep <7 hours on average per night during the week (80% vs 33.3%; P < .05). The mean and instantaneous vertical load rates were not different between groups. Women with a history of high-risk BSI were more likely to exhibit risk factors for poor bone health, including lower BMD, while load rates did not distinguish women with a history of BSI.