A New Design Problem in the Formulation of a Special Moment Resisting Connection Device for Preventing Local Buckling

In the present paper an improved formulation devoted to the optimal design problem of a special moment resisting connection device for steel frames is proposed. This innovative device is called a Limited Resistance Plastic Device (LRPD) and it has been recently proposed and patented by some of the authors. It is thought to be preferably located at the extremes of the beam, connecting the beam end cross section with the relevant column. The typical device is a steel element characterized by symmetry with respect to three orthogonal barycentric planes and constituted by a sequence of three portions with abrupt cross section changes. The main novelty of the present proposal is related to the design of special geometry for the optimal device ensuring that it possesses a reduced resistance with respect to the relevant connected beam element, is characterized by an equivalent bending stiffness equal to the one of the connected beam elements and exhibits full plastic deformations avoiding any local instability phenomenon. The optimal design is formulated as a minimum volume one and is subjected to suitable constraints on the geometry of the device and on its elastic and plastic behavior. The optimization problem is a strongly non-linear programming one and it is solved by adopting an interior-point algorithm that is available in the MATLAB Optimization Toolbox. The numerical simulations are devoted to the most used standard steel profiles (IPE, HE) and the results prove the great reliability of the proposed device. In addition, the relevant elastic and plastic domains of the designed devices are defined, and the expected behavior of the device is verified by appropriate 3D finite element models in the ABAQUS environment.

APPLICATION OF TWO-BIT DITHERED DISCRETE FOURIER BASIS FUNCTIONS IN ELECTRICITY MEASUREMENT

Paper defines an algorithm for generating two - bit dithered discrete Fourier basis functions (2BDDFBF) used in a Stochastic Digital Discret Fourier Transformation (SDDFT) processor. Based on the theoretical criterion of marginal precision, and norm and orthogonality, the orthonormality of DFT with 32 harmonics was confirmed by simulation and experimentally. The experiment was detailed and comprehensive, both for standardization and for both types of orthogonality. It was performed in 236800000 points in each of the three variants of orthonormalization. The matching of theoretical and experimental precision is very acceptable and it can be said with great reliability that the proposed algorithm for generating DDFBF is correct. 2BDDFBF play key role in electricity measurement what is emphasized in the paper. .

A Comparison of Fresh Pork Colour Measurements by Using Four Commercial Handheld Devices

The objective of this study was to evaluate the performance of different low-cost instruments to measure pork colour in comparison to Minolta spectrophotometers and industry subjective standards. Canadian pork colour standards and commercial meat (252 loin chops and 46 tenderloins) were measured using two Minolta (CM 700D) spectrophotometers, four Nix sensors (two Nix Pro II and two Nix QC), and four Spectro devices (two Spectro 1 and two Spectro 1 Pro). Using Bland-Altman plots, all hand-held devices revealed similar performance on colour coordinates, except for the Nix Pro II, which had more variability on a* value, and Spectro 1 Pro on b* value, when compared to Minolta measurements. Low RSD values (< 5%) were obtained from repeated measurements on Canadian colour standards. The trend of colour coordinates on colour scores (0–6) were similar for all four commercial instruments, except for a* from Nix Pro and b* from Spectro 1. The correlation coefficients between subjective standards and colour coordinates from the Nix and Spectro devices were slightly higher than the Minolta spectrophotometers. Even though Nix and Spectro 1 series instruments generated different absolute colour coordinate values on meat samples, these pocket-size instruments presented great reliability to measure pork surface colour. However, operational limitations of the instruments, such as the internal calibration time between samples for the Spectro 1 series, should also be considered.

Cross sections Data Adjustment For KRITZ-2:13

Over the past years, the cross-sections reaction data has been re-evaluated several times, in order to approximate the nuclear model measurements with the predictions with great reliability. In our work, uncertainty analysis caused by the data on the neutron factor (Keff) and the reactivity temperature coefficient (RTC), in addition to nuclear data adjustment related to the nuclear reactor physics have been done for KRITZ-2:13 reactor, with ENDF/B - VII.1, ENDF/B - VIII.0 and JENDL - 4.0 evaluations by the nuclear code MCNP6.1. Our analysis detects that the greatest uncertainty on Keff and RTC in the studied libraries comes from the capture and fission reaction contributions respectively, for U-238 and U-235. The previous reactions and their covariances were adjusted using the generalized least squares method (GLLSM), in order to contribute to improve the data needed for neutron simulation of experiments and to ensure the installations safety, where Keff and RTC represent neutron parameters reflecting the modification effects in the data.

Relationship between General Jump Types and Spike Jump Performance in Elite Female and Male Volleyball Players

In performance testing, it is well-established that general jump types like squat and countermovement jumps have great reliability, but the relationship with volleyball spike jumps is unclear. The objectives of this study were to analyze the relationship between general and spike jumps and to provide improved models for predicting spike jump height by general jump performance. Thirty female and male elite volleyball players performed general and spike jumps in a randomized order. Two AMTI force plates (2000 Hz) and 13 Vicon MX cameras (250 Hz) captured kinematic and kinetic data. Correlation and stepwise-forward regression analyses were conducted at p < 0.05. Simple regression models with general jump height as the only predictor for spike jumps revealed 0.52 ≤ R2 ≤ 0.76 for all general jumps in both sexes (p < 0.05). Alternative models including rate of force development and impulse improved predictions during squat jumps from R2 = 0.76 to R2 = 0.92 (p < 0.05) in females and from R2 = 0.61 to R2 = 0.71 (p < 0.05) in males, and during countermovement jumps with arm swing from R2 = 0.52 to R2 = 0.78 (p < 0.01) in males. The findings include improved prediction models for spike jump height based on general jump performance. The derived formulas can be applied in general jump testing to improve the assessment of sport-specific spike jump performance.

Retention and Clinical Performance of Zirconia Crowns: A Comprehensive Review

Zirconia has been used for rehabilitation of edentulous spaces approximately for a decade, and there have been several reports regarding the clinical performance and retention of zirconia crowns. Outstanding mechanical properties, biocompatibility, and excellent aesthetics make zirconia-based crowns as a popular crown among the current all-ceramic crowns in restorative dentistry. However, restoration with a zirconia crown is a challenging treatment. The goal of this study was to assess the current literature to summarize the studies reporting the effective risk factors on retention of zirconia crowns to provide clinicians with a useful point of view in the decision-making process for use of these restorations. Literature based-search was performed to find related articles until August 2020 using EMBASE, Google Scholar, and MEDLINE. Search terms used were “zirconia restorations properties,” “zirconia crowns clinical performance,” “zirconia crown survival,” “biological complications,” and “zirconia crown retention.” Results were limited to papers available in English. The references of all related literature were also searched for further citations. Overall, although clinical long-term and follow-up studies are a vital requirement to conclude that zirconia has great reliability, it seems that zirconia crown restorations are both well tolerated and sufficiently resistant.

Thermo-Diffusion and Multi-Slip Effect on an Axisymmetric Casson Flow over a Unsteady Radially Stretching Sheet in the Presence of Chemical Reaction

The objective of this article is to investigate the impacts of thermo-diffusion effect on unsteady axisymmetric Casson flow over a time-dependent radially stretching sheet with a multi-slip parameter and the force of chemical reaction. We employed an established similarity transformation to this non-linear partial differential system to convert it into a system of ordinary differential equations. The numerical results are attained for this system by using KELLER-BOX implicit finite difference scheme. It has great reliability and accuracy even a very short time period for computational simulation. The impacts of influential flow parameters on fluid flow are sketched through graphs and the numerical results are thoroughly argued. The temperature, velocity and wall concentration control parameters are analyzed. (i) It is witnessed that chemical reaction is not favorable to enhance the velocity profile. (ii) Multi-slip parameters vary inversely with velocity profile. (iii) The fluid concentration in its boundary layer decreases with the increase of heavier species, the parameter of the reaction rate and the exponent of power law for fluids having Prandtl number = 10.0, 15.0, 20.0 and 25.0. Moreover, the skin-friction-coefficient factor and Nusselt-number are compared with the published work. A strong numerical solution agreement is being observed.

Métodos de evaluación del equilibrio estático y dinámico en niños de 8 a 12 años (Evaluation methods of static and dynamic balance in children aged 8 to 12 years old)

El equilibrio es una de las capacidades motrices, fundamentales para las actividades diarias y el aprendizaje deportivo, por lo que su fortalecimiento desde las etapas tempranas del niño redunda en un mejor desempeño físico y favorece su gusto por involucrarse en actividades no sedentarias. Objetivo: Analizar las metodologías actuales para evaluar el equilibrio estático y dinámico en niños de ocho a 12 años sin discapacidad. Método: Fueron incluidos los estudios publicados entre 2000 y 2019, escritos en inglés y en español, donde participaban niños típicos o regulares, entre 8 y 12 años de edad, textos completos y que utilizaron una metodología de evaluación del equilibrio estático y/o dinámico con las palabras claves: Equilibrio y/o balance; equilibrio y/o entrenamiento, equilibrio y/o evaluación. Los estudios se clasificaron en: evaluación del equilibrio estático, equilibrio dinámico y estudios que conjuntan equilibrio dinámico y estático. Resultados: Dieciocho estudios cumplieron los criterios de inclusión para la revisión. Doce estudios hicieron uso de instrumentos que evaluaron el equilibrio estático y dinámico, cuatro el equilibrio estático y dos el dinámico. Conclusiones: Las baterías de evaluación del equilibrio siguen siendo muy utilizadas debido a su fácil realización y requerir pocos materiales para su aplicación. Sin embargo, las plataformas de evaluación del equilibrio son cada vez más utilizadas debido a su gran confiabilidad y rapidez en la obtención de los resultados.Summary. Balance is one of the fundamental motor skills for daily activities and sports learning, so strengthening it from early stages of childhood results in better physical performance, as well as it favors their preference towards engaging in non-sedentary activities. Objective: To analyze the current methodologies employed to evaluate static and dynamic balance in children without disability aged eight to 12 years old. Method: Studies published between 2000 and 2019, written in English and Spanish, with typical or regular children between 8 and 12 years of age as samples, presenting full texts, and using static and / or dynamic balance evaluation methodologies were included. Keywords were used as follows: Balance and / or balance; balance and / or training, balance and / or evaluation. The studies were classified into: evaluation of static balance, dynamic balance, and studies that combine dynamic and static balance. Results: Eighteen studies met the inclusion criteria for the review. Twelve studies made use of instruments that evaluated the static and dynamic balance, four the static balance, and two the dynamic balance. Conclusions: balance evaluation batteries are still widely used due to their easy implementation and require few materials for their application. However, balance assessment platforms are increasingly used due to their great reliability and speed in obtaining results.

Distributed Model Predictive Control of Steam/Water Loop in Large Scale Ships

In modern steam power plants, the ever-increasing complexity requires great reliability and flexibility of the control system. Hence, in this paper, the feasibility of a distributed model predictive control (DiMPC) strategy with an extended prediction self-adaptive control (EPSAC) framework is studied, in which the multiple controllers allow each sub-loop to have its own requirement flexibility. Meanwhile, the model predictive control can guarantee a good performance for the system with constraints. The performance is compared against a decentralized model predictive control (DeMPC) and a centralized model predictive control (CMPC). In order to improve the computing speed, a multiple objective model predictive control (MOMPC) is proposed. For the stability of the control system, the convergence of the DiMPC is discussed. Simulation tests are performed on the five different sub-loops of steam/water loop. The results indicate that the DiMPC may achieve similar performance as CMPC while outperforming the DeMPC method.