Dynamic Analysis of a Spherical Parallel Robot Used for Brachial Monoparesis Rehabilitation

This paper presents studies on the dynamic analysis of the ASPIRE robot, which was designed for the medical recovery of brachial monoparesis. It starts from the virtual model of the existing version of the ASPIRE robot, which is analysed kinematically and dynamically by numerical simulations using the MSC.ADAMS software. For this purpose, this paper presents theoretical aspects regarding the kinematics and dynamics of the markers attached to the flexible bodies built in a specifically developed MSC.ADAMS model. Three simulation hypotheses are considered: (a) rigid kinematic elements without friction in couplings, (b) rigid kinematic elements with friction in couplings, and (c) kinematic elements as deformable solids with friction in couplings. Experimental results obtained by using the physical prototype of ASPIRE are presented. Results such as the connecting forces in the kinematic joints and the torques necessary to operate the ASPIRE robot modules have been obtained by dynamic simulation in MSC.ADAMS and compared with those determined experimentally. The comparison shows that the allure of the variation curve of the moment obtained by simulation is similar to that obtained experimentally. The difference between the maximum experimental value and that obtained by simulation is less than 1%. A finite element analysis (FEA) of the structurally optimized flexion/extension robot module is performed. The results demonstrate the operational safety of the ASPIRE robot, which is structurally capable of supporting the stresses to which it is subjected.

Kinematic analysis and simulation of 6-DOF vehicle driving simulator

In order to reasonably design the six degrees of freedom turntable (hereinafter referred to as the transfer table), based on the structure size and motion index parameters of the turntable, The motion mechanics calculation model was established to simulate and analyze the mechanical variation curve of singing platform under different motion modes. The analysis shows that when the upper platform load and the component mass are 3000 kg, the maximum action force of the rotating platform support moving cylinder is 1376.4 kg.

Research on the Volumetric Efficiency of a Novel Stacked Roller 2D Piston Pump

In order to improve the volumetric efficiency of the axial piston pump, this paper proposes a novel stacked roller 2D piston pump. It utilizes the alternate communication between the distribution cylinder and the oil intake and discharge ports of the housing to realize the flow distribution. While removing the independent flow distribution mechanism of the traditional piston pump, the leakage loss at the distribution friction pair can be reduced to improve the volumetric efficiency. Based on the flow distribution principle, an analytical model of the volumetric efficiency of the stacked roller 2D piston pump was established. Then, a co-simulation model of the whole pump was built using both the Simulink and AMESim software. The variation curve of output flow and leakage flow under different load pressures and rotational speeds was obtained, as well as the influence of backflow, axial leakage, and circumferential leakage on the volumetric efficiency. On this basis, a prototype of the stacked roller 2D pump was designed and manufactured in order to measure the output flow under different load pressures and rotational speeds, and a dedicated test bench was established. The experimental results are consistent with the simulation results; when the rotational speed is 6000 rpm and the load pressure is 5 MPa, the volumetric efficiency of the prototype pump can reach 98.6%. The research work validates that the novel stacked roller 2D piston pump has high volumetric efficiency.

Impact of The Structure on The Thermal Burnout Effect Induced by Microwave Pulses of PIN Limiter Diodes

Positive-intrinsic-negative (PIN) limiter are widely used to protect sensitive components from leakage power itself and adjacent high-power injection. Being the core of a PIN limiter, the PIN diode is possible to be burnt out by the external microwave pulses. Here, numerical simulations by our self-designed device-circuit joint simulator were carried out to study the influences of the I layer thickness and the anode diameter of the PIN diode on the maximum temperature variation curve of the PIN diode limiter. The damage threshold criterion in the numerical simulation was first studied by comparing experimental results with simulation results. Then, we determined the impact of the structure on the thermal burnout effect induced by microwave pulses of PIN limiter diodes.

Addressing the challenges in projects of water treatment plants and storage of potable water: a case studies of the water supply system in the state of Goiás, Brazil

To elaborate efficient and economical water supply systems is one of the main objectives in the sanitation companies water system projects. In order to address the challenges faced in reaching this objective, this study aims to identify, first, the relation between the percentage of non-conformed samples in treated water and the inefficiency of the filtering units installed in the water treatment plant, and second, if, by drawing the consumption variation curve it is the most efficient way to predict the storage tanks volume—comparing necessary capacity, determined by the consumption curve, and installed capacity, predict by the outdated Brazilian normative. In order to reach answers for these two questions, this study measured the operating efficiency of the treatment plant as well as have set a quantitative comparison between the two dimensioning criteria for storage tanks volume present in the literature. As a result, the analysis provided the authors to detect a focus of contamination in the single-layered filtering units, limited by the filtering capacity of 2–6 m3/(m2 day), whilst operating at 333.13 m3/(m2 day). As well as to detect by the drawing of the consumption variation curve an oversize of 68% and 60% in the dimensioning of the studied storage tanks. With the results provided by this analysis approach, it was possible to efficiently detect and correct critical impairments in the treatment phase and to conclude that a long-term analysis should be drawn in order to affirm if the consumption variation curve is the best design methodology for the reservoirs.

GIUSEPPE FOLGHERAITER: THE ITALIAN PIONEER OF ARCHAEOMAGNETISM

ABSTRACT The history of the science of archaeomagnetism conventionally starts in 1600 with the publication of William Gilbert's monumental work De Magnete, but the theoretical basis of this scientific field has to be positioned at the end of the nineteenth century. In Italy at that time, a number of scientists such as Giambattista Beccaria, Macedonio Melloni and Silvestro Gherardi, were working on magnetic field characteristics and their work variously contributed to the early study of Earth and rock magnetism. A major contribution to the birth of paleomagnetism as a science, and archaeomagnetism as a dating technique, was produced by Giuseppe Folgheraiter (1856–1913) by means of his research on the magnetic properties of volcanic deposits and his attempts to date ancient pottery of different epochs based on the magnetic properties of clay materials. Initially, Folgheraiter studied the rock magnetism of the volcanic rocks of Latium where he replicated the findings of Macedonio Melloni, who had studied Vesuvius lavas, and found that volcanic rocks are affected by a permanent magnetization. In addition, Folgheraiter verified the discovery by Filippo Keller of the Punti distinti. Folgheraiter also made the innovative proposal that lightning strongly influences the magnetic properties of lavas resulting in magnetic disorder. The main analytical effort of Folgheraiter at the end of the nineteenth century was dedicated to the study of the variations of magnetic inclination in different epochs as registered in archaeological pottery. He produced archaeomagnetic sets of analyses on 191 samples grouped into 10 epochs, that resulted in the first reconstruction of a geomagnetic secular variation curve (SVC). Even if nowadays the Folgheraiter analytical results have been replaced by more precise measurements, a great portion of the development of modern archaeomagnetic techniques originated with Folgheraiter’s experiments and intuitions. Many of those advances were improved upon only during the first half of the twentieth century by Emile Thellier (1904–1987). Actually, the well-known work by Thellier, resulting in the birth of the Saint Maur archaeomagnetic laboratory at the Institut de Physique du Globe de Paris, had as a starting point the theories and suggestions developed by Giuseppe Folgheraiter. Based on the studies by Thellier, the well-known secular variation curve for France was derived, later to be perfected by Ileana Bucur in 1994.

Detecting 24 Kinds of Cytokines Via Flow Cytometry Aimplex Kit Is an Effective Way to Monitor CRS after CAR-T Cells Infusion

Introduction: Cytokine release syndrome (CRS) is a serious side effect of chimeric antigen receptor-T cell (CAR-T) therapy. Effective cytokine monitoring can provide support for early prevention and treatment. As more and more promising markers have been identified to be associated with CRS responses, traditional ELISA method is inapplicable because it's sample-consuming, low flexibility, and difficult to detect multiple cytokines simultaneously. Aimplex kit, a new high-throughput technique based on flow cytometry(FCM) and micro beads has been testified a effective way to monitor multiple cytokines in peripheral blood(PB) samples. If a new suitable cytokines panel is established to monitor the variation curve of multiple cytokines in patients' PBs post CAR-T therapy, study the relationship between clinical symptoms and the lab results, even build a cytokines database of CAR-T therapy, it would offer a promising support to prevent and handle CRS. On the other hand, by studying the relationship between cytokines and activated cells, we might investigate mechanisms of CRS and explore more related markers. Methods: A two tubes panel was designed to detect 24 cytokines, including IFN-γ/IL-1β/IL-2/IL-4/IL-5/IL-6/IL-8/IL-10/IL-12p70/IL-17A/IL-17F/IL-22/TNF-α/TNF-β, and sCD25/GM-CSF/IL-15/MCP-1/GranzymeB/Reg3A/ST2/TNFRSF1A/Elafin/MIP-1 alpha. 50 PB samples from complete response(CR) patients without CAR-T therapy were detested as normal controls to establish the normal values of 24 cytokines. 81 patients who infused CAR-T cell in Hebei Yanda Ludaopei Hospital from January to June 2020 were selected. Serum were collected on 0d, 4d, 7d, 11d, 15d, 20d and 30d after infusion, and 24 cytokines were detected by FCM Aimplex. Of which 31 patients were selected for methodological comparison between FCM and ELISA by detecting four routine cytokines, IL-6, IFN-γ, TNF-α and sCD25. 66 Patients were divided into 2 groups according to clinical manifestations, 60 patients without or mild CRS were classified as low grade CRS group, 6 patients with grade 2 or 3 CRS were classified as high grade CRS group. Results: The comparative test showed that a good relationship between the results of ELISA and Aimplex kit, showing similar time-cytokines variation curve of PBs after CAR-T treatment. The concentrations of IL-2, IL-10, IL-12p70, IL-17A, IL-17F, MCP-1, ST-2s, IL-5, IL-6 and IFN-γ were significantly higher in high CRS grade group. By comparing the proportion of CAR-T+, CD8+ and CD4+ T cells in CD3+ cells and the concentration of cytokines in PB specimens, there were obvious positive correlations between percentages of CAR-T+, CD8+ T cells and most cytokines, and negative correlation between proportion of CD4+ T cells and most cytokines. Conclusions: Detecting 24 kinds of cytokines by Aimplex kit is a promising method, which is time and specimens saving, and can cost-effectively reflect the cytokine situation in PBs from patients post-CAR-T treatment. Increasing the sample size and establishing a cytokines database will be helpful for monitoring, early prevention and control of side effects after CAR-T treatment. Disclosures No relevant conflicts of interest to declare.

Analysis and optimization of the spin beam in the CCA-5000 Cuban sugarcane harvester

A linear dynamic study of the tensional status of the unloading conveyor´s spin beam in the new model CCA-5000 Cuban sugarcane harvester is carried out. The dynamic coefficients were determined using a strain gauge experimental evaluation of the KTP-23 harvester, which is a similar model in structure to the CCA-5000. A finite elements analysis is used to obtain the safety distribution factor and the tensions in the beam for different load combinations linked to a dynamic variation curve of the loads. Aiming to verify the presence or not of large amplitudes on the system oscillations caused by the resonance phenomenon, an analysis of the frequency modes for each load status is conducted, and the results are compared with the terrain irregularities frequencies on which the harvester moves. Finally, taking into account the previous results, the shape of the beam is optimized in order to decrease its steevolume.