Preparation Technique and EMI Shielding Evaluation of Flexible Conductive Composite Fabrics Made by Single and Double Wrapped Yarns

Electronics products and communication equipment release electromagnetic (EM) waves in service. EM waves affect biological health and precision instrument accuracy. This study purposes to fabricate flexible conductive composite fabric which is made of complex yarn using metal (stainless steel, copper) fibers and PET filaments. Complex yarn is formed by a rotor twisting machine, at varying values of wrapped number (6.5-16 turns/cm) and lamination number (single-layer, double-layer). Results show that when the complex yarn was wrapped 16 turns/cm, volume resistivity reached 2.9 Ohm-cm and conductivity reaches 0.408 S/cm. Four layers of conductive composite plied with 0°/90°/ 0°/ 90° resulted in the optimum electromagnetic shielding effectiveness, up to 47.7 dB.

Pump and Valve Inservice Testing: How Pump and Valve Testing Evolved

The O&M Code was developed when it was decided to move Pump and Valve In-Service Testing Requirements from ASME Boiler and Pressure Vessel Code Section XI to a standalone Code. IST for Pumps was originally is ASME Section XI IWP and for Valves IWV. Safety and Relief Valves were a Power Test Code and not in the scope of the ASME Boiler and Pressure Vessel Code. IWP and IWV were developed after plants had been designed and built. The desire was that no back-fits were to be required to comply with IST requirements. After the 1986 Edition, IWP and IWV requirements were moved into O&M. Appendix 1 of OM was what used to be the Power Test Code. While this was going on, the NRC issued what has been called “the Richardson Letter”. Among other things, that letter required that IST for pumps better asses the condition of the pumps by putting higher accuracy instrumentation on the test pipe. For many plants, this was the minimum recirculation pipe. Over the course of time, the committee was able to get agreement that if a centrifugal pump were tested “back on its curve” increased instrument accuracy would be meaningless. This was the genesis of what we now call comprehensive Pump testing. Additionally, there were several alternative methods for valve testing that had been developed. It became clear, that simple periodic stroke timing of a power operated valve was simply not adequate for detecting degrading performance. This presentation will discuss how Pump and Valve In Service Testing evolved to what it is today and discuss what might be alternatives in the future. I want to thank Robert Parry, who provided some insights into this presentation specifically where my memory needed a bit of jogging. Paper published with permission.

Instrument accuracy influence on kinematics of rotary traverse of axial gear set with horizontal jet thrust in a group tractive drive of a lokomotive

Objective: To obtain analytical responses of linear and angular movements of horizontal jet thrust and axial reduction unit, appearing in the process of their production and group tractive drive assembly, occurring as a result of vertical wheelset and engine’s undercarriage frame shifts during engine movement. The given responses are the basis for identifying its velocity, acceleration, and dynamic loads on drive components, as well as searching for methods to boost drive components reliability, taking into account its constructive specificities and running conditions. Methods: Analytical responses were identified on the basis of higher mathematics, the laws of theoretical mechanics as well as trigonometry knowledge application. Results: Analytical responses of kinematic spatial movements of horizontal jet thrust and an axial reduction unit with instrument accuracy of a group tractive drive were obtained from vertical engine’s undercarriage frame shifts and locomotives wheelset. Boundary conditions of jet thrust slopes were detected, as well as center lines of axial reduction units. The analysis of established relations was performed. Possible scheme variants of spatial movements of horizontal jet thrust and a wheel set axial reduction unit in engine’s undercarriage frame were presented with possible discrepancies of linear dimensions from production tolerance. Characteristic curves of vertical shifts of actual towline constructions from vertical shifts of undercarriage frame during locomotive’s movement were graphed. Practical importance: On the basis of obtained relations the analysis of linear displacement, angular velocities and accelerations of jet thrusts and wheel set axial reduction units is possible, as well as the generation of rational and robust wheel set cardan tractive gear constructions for locomotives with minimal dynamic load on its elements. The results of analytical research might be applied in the designing of new engines with high dynamic parameters.

The ISAR Instrument Uncertainty Model

Measurements of sea surface temperature at the skin interface () made by an Infrared Sea Surface Temperature Autonomous Radiometer (ISAR) have been used for a number of years to validate satellite sea surface temperature (SST), especially high-accuracy observations such as made by the Advanced Along-Track Scanning Radiometer (AATSR). The ISAR instrument accuracy for measuring is ±0.1 K (Donlon et al.), but to satisfy Quality Assurance Framework for Earth Observation (QA4EO) principles and metrological standards (Joint Committee for Guides in Metrology), an uncertainty model is required. To develop the ISAR uncertainty model, all sources of uncertainty in the instrument are analyzed and an uncertainty value is assigned to each component. Finally, the individual uncertainty components are propagated through the ISAR retrieval algorithm to estimate a total uncertainty for each measurement. The resulting ISAR uncertainty model applied to a 12-yr archive of measurements from the Bay of Biscay shows that 77.6% of the data are expected to be within ±0.1 K and a further 17.2% are within 0.2 K.

Misclassification due to age grouping in measures of child development

PurposeScreens for developmental delay generally provide a set of norms for different age groups. Development varies continuously with age, however, and applying a single criterion for an age range will inevitably produce misclassifications. In this report, we estimate the resulting error rate for one example: the cognitive subscale of the Bayley Scales of Infant and Toddler Development (BSID-III).DesignData come from a general population sample of 594 children (305 male) aged 1 month to 42.5 months who received the BSID-III as part of a validation study. We used regression models to estimate the mean and variance of the cognitive subscale as a function of age. We then used these results to generate a dataset of one million simulated participants and compared their status before and after division into age groups. Finally, we applied broader age bands used in two other instruments and explored likely validity limitations when different instruments are compared.ResultsWhen BSID-III age groups are used, 15% of cases are missed and 15% of apparent cases are false positives. Wider age groups produced error rates from 27% to 46%. Comparison of different age groups suggests that sensitivity in validation studies would be limited, under certain assumptions, to 70% or less.ImplicationsThe use of age groups produces a large number of misclassifications. Although affected children will usually be close to the threshold, this may lead to misreferrals. Results may help to explain the poor measured agreement of development screens. Scoring methods that treat child age as continuous would improve instrument accuracy.

Research on 3D Reconstruction of Flatness Error Measurement System

Basis on the analysis of the plate flatness detection, some problems of the traditional flatness measuring method is pointed out and the 3D reconstruction method of flatness is proposed. The digital flatness measuring instrument is designed, and the measured plane information is entered into the computer, then the data processing is completed by software, which solves the problem of amounts of data, complicated calculation and low accuracy of traditional measurement method. The 3D reconstruction of surface morphology is completed by OpenGL and BCB, to make the information of flatness more sufficient and intuitive. To verify the validity of the measurement, use the flatness function module of dual-frequency laser interferometer to evaluate the instrument accuracy, the results show that it reaches the expected precision index.