scholarly journals Study on Vibration Reduction Due to Pile-Raft Foundation for High-Tech Lab Based on Frequency Sweep Test

2021 ◽  
Author(s):  
Yan Xia
Keyword(s):  
Vibration Reduction ◽  
Vertical Direction ◽  
Single Frequency ◽  
High Tech ◽  
Vibration Exciter ◽  
Measurement Results ◽  
Acquisition Device ◽  
Frequency Sweep Test ◽  
Data Acquisition Device

Evaluation of the vibration reduction of piled-slab is of great significance for the layout of process and power equipment in high-tech facilities. In-situ measurement was performed to study the vibration reduction of the piled-slab of a high-tech lab. Slab vibrations with frequencies of 10 Hz to 60 Hz with steps 5 Hz were induced by an electromagnetic vibration exciter. INV3062U data acquisition device and 941B sensor were used to measure the velocities in the vertical direction at six measurement locations on the slab surface. For single frequency, the measurement results showed that the peak values of the slab vibration velocities generally decayed nonlinearly as the distance increased, however, the attenuations of 25 Hz, 35 Hz, 40 Hz, 50 Hz and 60 Hz slab vibrations were not monotonically.

MONITORING AND PREDICTIVE ANALYTICS OF TECHNOLOGICAL EQUIPMENT ON THE BASED OF INDUSTRIAL INTERNET OF THINGS

2020 ◽  
pp. 7-12
Author(s):  
С.Л. Добрынин ◽  
В.Л. Бурковский
Keyword(s):  
Internet Of Things ◽  
Data Acquisition ◽  
Predictive Analytics ◽  
Actual State ◽  
Monitoring And Control ◽  
Industrial Internet Of Things ◽  
Machining Time ◽  
Industrial Internet ◽  
Acquisition Device ◽  
Data Acquisition Device

Произведен обзор технологий в рамках концепции четвертой промышленной революции, рассмотрены примеры реализации новых моделей управления технологическими процессами на базе промышленного интернета вещей. Описано техническое устройство основных подсистем системы мониторинга и контроля, служащей для повышения осведомленности о фактическом состоянии производственных ресурсов в особенности станков и аддитивного оборудования в режиме реального времени. Архитектура предлагаемой системы состоит из устройства сбора данных (УСД), реализующего быстрый и эффективный сбор данных от станков и шлюза, передающего ликвидную часть информации в облачное хранилище для дальнейшей обработки и анализа. Передача данных выполняется на двух уровнях: локально в цехе, с использованием беспроводной сенсорной сети (WSN) на базе стека протоколов ZigBee от устройства сбора данных к шлюзам и от шлюзов в облако с использованием интернет-протоколов. Разработан алгоритм инициализации протоколов связи между устройством сбора данных и шлюзом, а также алгоритм выявления неисправностей в сети. Расчет фактического времени обработки станочных подсистем позволяет более эффективно планировать профилактическое обслуживание вместо того, чтобы выполнять задачи обслуживания в фиксированные интервалы без учета времени использования оборудования We carried out a review of technologies within the framework of the concept of the fourth industrial revolution; we considered examples of the implementation of new models of process control based on the industrial Internet of things. We described the technical structure of the main subsystems of the monitoring and control system to increase awareness of the actual state of production resources in particular machine tools and additive equipment in real time. The architecture of the proposed system consists of a data acquisition device (DAD) that implements fast and efficient data collection from machines and a gateway that transfers the liquid part of information to the cloud storage for further processing and analysis. We carried out the data transmission at two levels, locally in the workshop, using a wireless sensor network (WSN) based on ZigBee protocol stack from the data acquisition device to the gateways and from the gateways to the cloud using Internet protocols. An algorithm was developed for initializing communication protocols between a data acquisition device and a gateway, as well as an algorithm for detecting network malfunctions. Calculating the actual machining time of machine subsystems allows us to more efficiently scheduling preventive maintenance rather than performing maintenance tasks at fixed intervals without considering equipment usage

scholarly journals Theoretical analysis and experimental research on multi-layer elastic damping track structure

2021 ◽  
Vol 13 (2) ◽  
pp. 168781402199497
Author(s):  
Guanghui Xu ◽  
Shengkai Su ◽  
Anbin Wang ◽  
Ruolin Hu
Keyword(s):  
Finite Element ◽  
Analytical Solution ◽  
Finite Element Simulation ◽  
Reaction Force ◽  
Vibration Reduction ◽  
Vertical Direction ◽  
Propagation Path ◽  
Track Structure ◽  
Test Results ◽  
Element Simulation

The increase of axle load and train speed would cause intense wheelrail interactions, and lead to potential vibration related problems in train operation. For the low-frequency vibration reduction of a track system, a multi-layer track structure was proposed and analyzed theoretically and experimentally. Firstly, the analytical solution was derived theoretically, and followed by a parametric analysis to verify the vibration reduction performance. Then, a finite element simulation is carried out to highlight the influence of the tuned slab damper. Finally, the vibration and noise tests are performed to verify the results of the analytical solution and finite element simulation. As the finite element simulation indicates, after installation of the tuned slab damper, the peak reaction force of the foundation can be reduced by 60%, and the peak value of the vertical vibration acceleration would decrease by 50%. The vibration test results show that the insertion losses for the total vibration levels are 13.3 dB in the vertical direction and 21.7 dB in the transverse direction. The noise test results show that the data of each measurement point is smoother and smaller, and the noise in the generating position and propagation path can be reduced by 1.9 dB–5.5 dB.

scholarly journals A Flexible Microcontroller-Based Data Acquisition Device

Sensors ◽  
2014 ◽  
Vol 14 (6) ◽  
pp. 9755-9775 ◽  
Author(s):  
Darko Hercog ◽  
Bojan Gergič
Keyword(s):  
Data Acquisition ◽  
Acquisition Device ◽  
Data Acquisition Device

The Detection And Mapping Of Defects In Organic Coatings Using Local Electrochemical Impedance Methods

1995 ◽  
Vol 411 ◽  
Author(s):  
S. R. Taylor ◽  
M. W. Wittmann
Keyword(s):  
Electrochemical Impedance ◽  
Organic Coatings ◽  
Single Frequency ◽  
Probe Design ◽  
Coating Failure ◽  
Local Electrochemical Impedance Spectroscopy ◽  
Physical Defects ◽  
Steel Substrates ◽  
Insight Into

ABSTRACTCoating failure initiates as a local event at defects which can result from chemical heterogeneities in the resin or physical defects such as bubbles, underfilm deposits, or pinholes. The ability to detect, map the location, as well as make quantitative in-situ measurements of coating heterogeneities will help identify the source of failure (i.e. coating chemistry, method of application, cure schedule, etc.) and provide insight into the mechanisms of coating degradation. This study used a 5 electrode arrangement to perform local electrochemical impedance spectroscopy (LEIS) on coated steel substrates. Using single frequency measurements, LEIS could successfully detect and map both intentional chemical heterogeneities and physical defects such as subsurface bubbles, underfilm deposits, and pinholes. Efforts to optimize probe design and instrumentation are ongoing.

scholarly journals Metallic conduction through van der Waals interfaces in ultrathin $$\hbox{Bi}_2\hbox{Te}_3$$ films

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shinichiro Hatta ◽  
Ko Obayashi ◽  
Hiroshi Okuyama ◽  
Tetsuya Aruga
Keyword(s):  
Photoelectron Spectroscopy ◽  
Van Der Waals ◽  
Vertical Direction ◽  
Conductivity Measurement ◽  
Spatial Separation ◽  
Mean Free Path ◽  
Conduction Path ◽  
Conductivity Increase ◽  
The Impact

AbstractWhile the van der Waals (vdW) interface in layered materials hinders the transport of charge carriers in the vertical direction, it serves a good horizontal conduction path. We have investigated electrical conduction of few quintuple-layer (QL) $$\hbox {Bi}_2\hbox {Te}_3$$ Bi 2 Te 3 films by in situ four-point probe conductivity measurement. The impact of the vdW (Te–Te) interface appeared as a large conductivity increase with increasing thickness from 1 to 2 QL. Angle-resolved photoelectron spectroscopy and first-principles calculations reveal the confinement of bulk-like conduction band (CB) state into the vdW interface. Our analysis based on the Boltzmann equation showed that the conduction of the CB has a long mean free path compared to the surface-state conduction. This is mainly attributed to the spatial separation of the CB electrons and the donor defects located at the Bi sites.

On properties of seawater defined by temperature, salinity, and pressure

2021 ◽  
Vol 79 (3) ◽  
pp. 121-147
Author(s):  
George Veronis
Keyword(s):  
Vertical Direction ◽  
Great Depth ◽  
Local Potential ◽  
Potential Density ◽  
Marine Research ◽  
Station Data ◽  
Starting Point ◽  
The World ◽  
Gravitational Stability

Hydrographic station data, consisting principally of temperature and salinity determinations, have been used by physical oceanographers to develop a climatological picture of the distribution of these quantities in the oceans of the world. Density as determined by Knudsen's formula, taken together with hydrostatic and geostrophic dynamics, also provides a crude picture of oceanic flow. However, the data probably contain substantially more information than has been derived from them in the past.The quantity that is orthogonal to potential-density curves in the S plane is suggested as a useful variable to complement the information contained in potential density. The derivation of this quantity, denoted by τ in this paper, is straightforward. A polynomial expression for τ that is suitable for computer calculations of τ from hydrographic station data is given. Shown are examples of hydrographic station data from the Atlantic plotted on the τσ diagram. The information contained in the τσ diagram shows many of the features exhibited in the TS plane. Vertical sections of τ appear to provide information about mixing in different parts of the Atlantic. The distribution of τ for abyssal waters at selected stations in the oceans of the world resembles the distribution of abyssal density as plotted by Lynn and Reid (1968). From the data presented, it appears that τ may serve as a good tracer for abyssal water movements.Since τ is defined to be orthogonal to σ, the expectation is that τ is a dynamically passive variable. However, since σ does not correlate with abyssal densities, it appears to lose dynamical significance at great depth, and τ assumes dynamical significance because of its orthogonality to σ. This unexpected feature leads to an exploration of the dynamical significance of σ. A natural starting point is the question of stability of abyssal water.A distinction is made between stability as determined by in situ determinations and as determined by the potential-density (σ) distribution. Simple examples are presented to show that analysis based on σ alone can lead to incorrect conclusions about gravitational stability of the water in the abyssal ocean. The reason is that seawater is a multicomponent thermodynamic system, and the thermodynamic coefficients are functions of pressure, salinity, and temperature. This functional dependence leads to adjustments in density as a water particle moves adiabatically in the vertical direction so that a layer of water that appears to be unstable near the surface may be stable (as determined by in situ determination) at great depth. A local potential density, which is simply the vertical integral of the in situ stability, is derived. This quantity gives a precise picture of gravitational stability in the vertical direction. Some distributions of local potential density are shown.Originally published May 15, 1972, in the Journal of Marine Research 30(2), 227???255.

scholarly journals Performance Evaluation of Cleanroom Environmental Systems

2003 ◽  
Vol 46 (1) ◽  
pp. 66-73 ◽  
Author(s):  
Tengfang Xu
Keyword(s):  
Environmental Performance ◽  
Energy Efficient ◽  
The United States ◽  
Energy Performance ◽  
Contamination Control ◽  
Performance Benchmarking ◽  
Power Intensity ◽  
Environmental Systems ◽  
Measurement Results

This paper presents in-situ measurement results for energy and environmental performance of 13 cleanroom systems located in the United States, including key metrics for evaluating cleanroom air system performance and overall electric power intensity. Comparisons with IEST Recommended Practice IEST-RP-CC012.1: Considerations in Cleanroom Design are made to examine the performance of cleanroom air systems. Based on the results, the paper discusses likely opportunities for improving cleanroom energy efficiency while maintaining effective contamination control. The paper concludes that there are wide variations in energy performance of cleanroom environmental systems, and that performance benchmarking can serve as a vehicle to identify energy efficient cleanroom design practices and to highlight important issues in cleanroom operation and maintenance.

scholarly journals Atmospheric CO2, CH4, and CO with CRDS technique at the Izaña Global GAW station: instrumental tests, developments and first measurement results

2017 ◽  
Author(s):  
Angel J. Gomez-Pelaez ◽  
Ramon Ramos ◽  
Emilio Cuevas ◽  
Vanessa Gomez-Trueba ◽  
Enrique Reyes
Keyword(s):  
Drift Rate ◽  
Inlet Pressure ◽  
Response Functions ◽  
Measurement Results ◽  
Ambient Measurements ◽  
Acceptance Tests ◽  
Term Maintenance

Abstract. At the end of 2015, a CO2/CH4/CO Cavity Ring-Down Spectrometer (CRDS) was installed at the Izaña Global Atmosphere Watch station (Tenerife, Spain) to improve the Izaña Greenhouse gases GAW measurement programme, and to guarantee the renewal of the instrumentation and the long-term maintenance of this programme. We present the results of the CRDS acceptance tests, the processing of raw data applied through novel numerical codes, and the response functions used. Also, the calibration results, the implemented water vapour correction, the target gas injection statistics, the ambient measurements performed from December 2015 to July 2017, and their comparison with other continuous in situ measurements are described. The agreement with other in situ continuous measurements is good most of the time for CO2 and CH4, but for CO is just outside the GAW 2-ppb objective. It seems the disagreement is not produced by significant drifts in the CRDS CO WMO tertiary standards. The main novelties are: 1) determination of a slight CO2 correction that takes into account changes in the inlet pressure/flow rate; 2) detailed justification of the use of virtual tanks to monitor the response function changes in time; 3) drift rate determination for the pressure and temperature sensors located inside the CRDS cavity; 4) novelties in the determination of the H2O correction for CO; and 5) determination and discussion of the origin of the CRDS-flow inlet pressure and H2O dependences.

scholarly journals In COM we trust: Feasibility of USB-based event marking

2021 ◽  
Author(s):  
Stefan Appelhoff ◽  
Tristan Stenner
Keyword(s):  
Data Analysis ◽  
Data Streams ◽  
Cost Effective ◽  
Computer Hardware ◽  
Parallel Port ◽  
Simulated Experiment ◽  
Extensive Documentation ◽  
Electrical Pulses ◽  
Acquisition Device ◽  
Data Acquisition Device

AbstractModern experimental research often relies on the synchronization of different events prior to data analysis. One way of achieving synchronization involves marking distinct events with electrical pulses (event markers or “TTL pulses”), which are continuously recorded with research hardware, and can later be temporally aligned. Traditionally, this event marking was often performed using the parallel port in standard personal computers. However, the parallel port is disappearing from the landscape of computer hardware, being replaced by a serial (COM) port, namely the USB port. To find an adequate replacement for the parallel port, we evaluated four microcontroller units (MCUs) and the LabJack U3, an often-used USB data acquisition device, in terms of their latency and jitter for sending event markers in a simulated experiment on both Windows and Linux. Our results show that all four MCUs were comparable to the parallel port in terms of both latency and jitter, and consistently achieved latencies under 1 ms. With some caveats, the LabJack U3 can also achieve comparable latencies. In addition to the collected data, we share extensive documentation on how to build and use MCUs for event marking, including code examples. MCUs are a cost-effective, flexible, and performant replacement for the disappearing parallel port, enabling event marking and synchronization of data streams.

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