scholarly journals Silicon-On-Nothing Micro-Pirani Gauge for Interior-Pressure Measurement

Proceedings ◽  
2018 ◽  
Vol 2 (13) ◽  
pp. 1079
Author(s):  
Andrey Kravchenko ◽  
Vladislav Komenko ◽  
Wolf-Joachim Fischer
Keyword(s):  
Crystalline Silicon ◽  
Sacrificial Layer ◽  
Field Tests ◽  
Cost Effective ◽  
Cavity Pressure ◽  
Sensing Element ◽  
Bottom Cavity ◽  
Pirani Gauge ◽  
Process Compatibility ◽  
Whole Life Cycle

In the current work, we present a compact and cost effective Pirani gauge based on Silicon-On-Nothing (SON) technology. The proposed design uses an innovative approach of etching the sensing element directly in a crystalline silicon membrane. Such configuration allows pressure dependent heat losses to act on the substrate not only through the bottom cavity and trenches but also via the top cavity on the lid, which is formed by means of a sacrificial layer. By ensuring process compatibility with other SON-based MEMS, the proposed device can be used as a tool for cavity pressure monitoring and product support over the whole life cycle of MEMS: ranging from fabrication to calibration during field tests. Performance of the device is investigated based on numerical simulations and measurements. Furthermore, work includes a discussion of the fabrication process along with an additional cavity pressure characterization.

Estimation of Crack Growth Life in Rail with a Squat Defect

2009 ◽  
Vol 417-418 ◽  
pp. 313-316 ◽  
Author(s):  
Hyun Kyu Jun ◽  
Won Hee You
Keyword(s):  
Growth Rate ◽  
Crack Growth Rate ◽  
Crack Growth ◽  
Rail Steel ◽  
Crack Tip ◽  
Cost Effective ◽  
Rolling Contact ◽  
Hertzian Contact ◽  
Maintenance Strategy ◽  
Whole Life Cycle

Rolling contact fatigue initiated defects such as surface corrugation, head check, squat, are one of growing problems in high speed railway line. A squat is generally developed below the rail surface and grows parallel to surface until it turns down into rail. Estimation of critical crack size and crack growth rate is an essential to prevent rail from failure and develop cost effective railway maintenance strategy. In this study, we predict crack growth rate of a rail with a squat defect. For this purpose, a rail model with a squat defect is developed. Timoshenko’s beam theory is applied to calculate the global bending stress at the crack tip and Hertzian contact model is applied to calculate the local contact stresses at the surface of rail by simulating rolling over a railway wheel on a rail. Stress intensity factors are calculated from the total stress at the crack tip. Fatigue crack growth curve of 60kg rail steel is applied to calculated crack growth rate. Software to predict crack growth life through whole life cycle is developed. We expect that we can make a more cost effective rail maintenance strategy by considering the crack growth analysis for a defective rail.

scholarly journals Molecularly Imprinted Nanoparticles Based Sensor for Cocaine Detection

Biosensors ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 22 ◽  
Author(s):  
Roberta D’Aurelio ◽  
Iva Chianella ◽  
Jack A. Goode ◽  
Ibtisam E. Tothill
Keyword(s):  
Electrochemical Impedance ◽  
Limit Of Detection ◽  
Solid Phase ◽  
Cost Effective ◽  
Cross Reactivity ◽  
P Value ◽  
Sensing Element ◽  
Molecularly Imprinted ◽  
Cost Effective Method ◽  
Cocaine Detection

The development of a sensor based on molecularly imprinted polymer nanoparticles (nanoMIPs) and electrochemical impedance spectroscopy (EIS) for the detection of trace levels of cocaine is described in this paper. NanoMIPs for cocaine detection, synthesized using a solid phase, were applied as the sensing element. The nanoMIPs were first characterized by Transmission Electron Microscopy (TEM) and Dynamic Light Scattering and found to be ~148.35 ± 24.69 nm in size, using TEM. The nanoMIPs were then covalently attached to gold screen-printed electrodes and a cocaine direct binding assay was developed and optimized, using EIS as the sensing principle. EIS was recorded at a potential of 0.12 V over the frequency range from 0.1 Hz to 50 kHz, with a modulation voltage of 10 mV. The nanoMIPs sensor was able to detect cocaine in a linear range between 100 pg mL−1 and 50 ng mL−1 (R2 = 0.984; p-value = 0.00001) and with a limit of detection of 0.24 ng mL−1 (0.70 nM). The sensor showed no cross-reactivity toward morphine and a negligible response toward levamisole after optimizing the sensor surface blocking and assay conditions. The developed sensor has the potential to offer a highly sensitive, portable and cost-effective method for cocaine detection.

Workstation Design Optimization Through a Simulation Model

1981 ◽  
Vol 25 (1) ◽  
pp. 374-378
Author(s):  
Mark S. Hoffman ◽  
Martin L. Cramer
Keyword(s):  
Simulation Model ◽  
Systems Design ◽  
Field Tests ◽  
Cost Effective ◽  
Control Device ◽  
Engineering System ◽  
Human Engineering ◽  
Integrated Network ◽  
Workstation Design ◽  
Marketing Tool

A man-machine systems simulation model was developed as a cost-effective marketing tool for systems design in the retail sales environment. SAINT (Systems Analysis Integrated Network of Tasks) modeling technique was chosen because of its capabilities to simulate complex human engineering system performances. Tasks performed at the workstations ranged from an automated real-time inventory control device requiring a high degree of man-machine interactivity to social interactions between the operator and customer. Network parameters were defined from performances observed both in laboratory and field tests. The model included the capability to mix and simulate multiple workstations within a given environment. Work surface dimensions, operator ability levels, and processing strategies were manipulated to maximize productivity. This approach to workstation design proved to be an effective method of systematically reducing the number of alternative configurations. It also reduces the requirement of elaborate time-consuming laboratory experiments to verify a proposed design concept. A conversational interface was developed to encourage its utilization by the untrained user.

scholarly journals Application of Microbial Bioenzymes in Soil Stabilization

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Eshetu Mekonnen ◽  
Ameha Kebede ◽  
Tekle Tafesse ◽  
Mesfin Tafesse
Keyword(s):  
Soil Stabilization ◽  
Raw Materials ◽  
Low Cost ◽  
Field Tests ◽  
Cost Effective ◽  
Green Technology ◽  
Engineering Properties ◽  
Soil Stability ◽  
Stabilizing Agents ◽  
Dust Generation

Soil stabilization is a mechanical or chemical alteration of one or more soil properties to create an improved soil material possessing the desired engineering properties. The aim of this article was to review bioenzyme-based soil stabilization techniques with an emphasis on bioenzymes production, mechanism of soil stabilization and future challenges, and opportunities of the sector. Soils are stabilized to increase strength and durability or to prevent erosion and dust generation. Cost-effective soil stabilization technology has been a fundamental part of any construction and is very important for economic growth in any country. In some cases, construction has been challenged due to the high cost of soil stabilization processes. Besides, methods of stabilizations using common stabilizing agents are getting costly. Currently, there is a growing interest to identify new and green technology to improve construction techniques and to expand the road network. Therefore, the search for new materials and improved techniques to process the local materials has received an increased focus. For developing countries, bioenzymes are now creating an opportunity to improve soil stability with tremendous effectiveness in the overall process of soil stabilization. In the world, bioenzymes have been used in different projects for several years and are generally proprietary products, often of patented formulation that needs intensive field tests. Currently, the use and production of bioenzymes is becoming the most promising key for the advancement of a country by saving time, energy, and finance. It also reduces environmental pollution due to carbon emission by the conventional stabilizers. Thus, a better understanding of this emerging technology is of utmost importance to exploit any improvement it can offer to soil stability. With little research and practice, it is possible to produce soil stabilizing bioenzymes using local raw materials. Due to this, production of low cost, easily and widely applicable, and environmentally friendly enzymatic formulations from locally available raw materials should be the interest of research and academic institutes of any country.

scholarly journals A Cost-Effective Method to Reproduce the Morphology of the Nearshore and Intertidal Zone in Microtidal Environments

2020 ◽  
Vol 12 (11) ◽  
pp. 1880
Author(s):  
Stefano Furlani ◽  
Valeria Vaccher ◽  
Vanja Macovaz ◽  
Stefano Devoto
Keyword(s):  
Intertidal Zone ◽  
Field Tests ◽  
Cost Effective ◽  
Time Lapse ◽  
3D Models ◽  
The North ◽  
Cost Effective Method ◽  
Photogrammetric Method ◽  
The Difference ◽  
Sea Wall

The photogrammetric method is widely used in coastal areas and in submerged environments. Time-lapse images collected with unmanned aerial vehicles are used to reproduce the emerged areas, while images taken by divers are used to reproduce submerged ones. Conversely, 3D models of natural or human-made objects lying at the water level are severely affected by the difference in refractive index between air and seawater. For this reason, the matching of 3D models of emergent and submerged coasts has been very rarely tested and never used in Earth Sciences. The availability of a large number of time-lapse images, collected at the intertidal zone during previous snorkel surveys, encouraged us to test the merging of 3D models of emerged and submerged environments. Considering the rapid and effective nature of the aforementioned program of swim surveys, photogrammetric targets were not used during image acquisition. This forced us to test the matching of the independent models by recognizing prominent landforms along the waterline. Here we present the approach used to test the method, the instrumentation used for the field tests, and the setting of cameras fixed to a specially built aluminum support console and discuss both its advantages and its limits compared to UAVs. 3D models of sea cliffs were generated by applying structure-from-motion (SfM) photogrammetry. Horizontal time-lapse images, collected with action cameras while swimming parallel to the coastline at nearly constant velocity, were used for the tests. Subsequently, prominent coastal landforms were used to couple the independent models obtained from the emergent and submerged cliffs. The method was pilot tested in two coastal sites in the north-eastern Adriatic (part of the Mediterranean basin). The first site was a 25 m sea wall of sandstone set within a small harbor, while the second site was a 150 m route below plunging limestone cliffs. The data show that inexpensive action cameras provide a sufficient resolution to support and integrate geomorphological field surveys along rocky coastlines.

scholarly journals Development of an autonomous flow-proportional water sampler for the estimation of pollutant loads in urban runoff

2020 ◽  
Vol 192 (9) ◽  
Author(s):  
Péter Budai ◽  
Máté Krisztián Kardos ◽  
Marcell Knolmár ◽  
Gábor Szemán ◽  
József Turczel ◽  
...  
Keyword(s):  
Monitoring Program ◽  
Field Tests ◽  
Cost Effective ◽  
Urban Runoff ◽  
Urban Environments ◽  
Sampling Efficiency ◽  
Wide Range ◽  
Water Sampler ◽  
Design Requirements ◽  
Runoff Events

Abstract Implementation of an extensive urban runoff monitoring program, targeting the quantification of heavy metal and organic micropollutant loads, necessitated the development of an autonomous water sampler. The design requirements for the device were to fulfill flow-proportional continuous composite sampling of urban runoff events in a widely customizable, relatively inexpensive, and simple way. In this paper, we introduce the concept along with the experiences gained from the first several months of field tests at seven pilot areas in Hungary that represent a wide range of urban environments. During the test period, prototype samplers were placed in natural (urban) streams as well as stormwater drainage pipes, resulting in a total of 97 automatic composite runoff samples. At two sites, an additional 28 manual grab samples were collected to represent time series from five distinct runoff events. Sampling efficiency was checked by comparing collected volumes with the theoretical ones (derived from pump mileage data). Ranges and ratios of concentrations measured from composite and grab samples were graphically interpreted in order to evaluate their representativeness. It has been shown that the concept is suitable for conducting cost-effective urban runoff characterization surveys targeting inter-event variability.

scholarly journals Measuring Transverse Displacements Using Unmanned Aerial Systems Laser Doppler Vibrometer (UAS-LDV): Development and Field Validation

Sensors ◽  
2020 ◽  
Vol 20 (21) ◽  
pp. 6051
Author(s):  
Piyush Garg ◽  
Roya Nasimi ◽  
Ali Ozdagli ◽  
Su Zhang ◽  
David Dennis Lee Mascarenas ◽  
...  
Keyword(s):  
Laser Doppler Vibrometer ◽  
Field Tests ◽  
Field Measurements ◽  
Cost Effective ◽  
Laser Doppler ◽  
Unmanned Aerial Systems ◽  
Dynamic Displacement ◽  
Railway Bridges ◽  
Industrial Adoption ◽  
Aerial Systems

Measurement of bridge displacements is important for ensuring the safe operation of railway bridges. Traditionally, contact sensors such as Linear Variable Displacement Transducers (LVDT) and accelerometers have been used to measure the displacement of the railway bridges. However, these sensors need significant effort in installation and maintenance. Therefore, railroad management agencies are interested in new means to measure bridge displacements. This research focuses on mounting Laser Doppler Vibrometer (LDV) on an Unmanned Aerial System (UAS) to enable contact-free transverse dynamic displacement of railroad bridges. Researchers conducted three field tests by flying the Unmanned Aerial Systems Laser Doppler Vibrometer (UAS-LDV) 1.5 m away from the ground and measured the displacement of a moving target at various distances. The accuracy of the UAS-LDV measurements was compared to the Linear Variable Differential Transducer (LVDT) measurements. The results of the three field tests showed that the proposed system could measure non-contact, reference-free dynamic displacement with an average peak and root mean square (RMS) error for the three experiments of 10% and 8% compared to LVDT, respectively. Such errors are acceptable for field measurements in railroads, as the interest prior to bridge monitoring implementation of a new approach is to demonstrate similar success for different flights, as reported in the three results. This study also identified barriers for industrial adoption of this technology and proposed operational development practices for both technical and cost-effective implementation.

scholarly journals Comparison of the Electrical Properties of PERC Approach Applied to Monocrystalline and Multicrystalline Silicon Solar Cells

2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Enyu Wang ◽  
He Wang ◽  
Hong Yang
Keyword(s):  
Solar Cells ◽  
Silicon Wafer ◽  
Crystalline Silicon ◽  
Cost Effective ◽  
Monocrystalline Silicon ◽  
Multicrystalline Silicon ◽  
Silicon Solar Cells ◽  
Next Generation ◽  
Crystalline Silicon Solar Cells ◽  
Commercial Applications

At present, the improvement in performance and the reduction of cost for crystalline silicon solar cells are a key for photovoltaic industry. Passivated emitter and rear cells are the most promising technology for next-generation commercial solar cells. The efficiency gains of passivated emitter and rear cells obtained on monocrystalline silicon wafer and multicrystalline silicon wafer are different. People are puzzled as to how to develop next-generation industrial cells. In this paper, both monocrystalline and multicrystalline silicon solar cells for commercial applications with passivated emitter and rear cells structure were fabricated by using cost-effective process. It was found that passivated emitter and rear cells are more effective for monocrystalline silicon solar cells than for multicrystalline silicon solar cells. This study gives some hints about the industrial-scale mass production of passivated emitter and rear cells process.

scholarly journals Simple, Fast, and Cost-Effective Fabrication of Wafer-Scale Nanohole Arrays on Silicon for Antireflection

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Di Di ◽  
Xuezhong Wu ◽  
Peitao Dong ◽  
Chaoguang Wang ◽  
Jian Chen ◽  
...  
Keyword(s):  
High Throughput ◽  
Crystalline Silicon ◽  
Colloidal Crystal ◽  
Cost Effective ◽  
Wafer Scale ◽  
Crystalline Silicon Solar Cells ◽  
Cost Effective Method ◽  
Nanohole Arrays ◽  
Coating Method ◽  
Hole Arrays

A simple, fast, and cost-effective method was developed in this paper for the high-throughput fabrication of nanohole arrays on silicon (Si), which is utilized for antireflection. Wafer-scale polystyrene (PS) monolayer colloidal crystal was developed as templates by spin-coating method. Metallic shadow mask was prepared by lifting off the oxygen etched PS beads from the deposited chromium film. Nanohole arrays were fabricated by Si dry etching. A series of nanohole arrays were fabricated with the similar diameter but with different depth. It is found that the maximum depth of the Si-hole was determined by the diameter of the Cr-mask. The antireflection ability of these Si-hole arrays was investigated. The results show that the reflection decreases with the depth of the Si-hole. The deepest Si-hole arrays show the best antireflection ability (reflection < 9%) at long wavelengths (>600 nm), which was about 28 percent of the nonpatterned silicon wafer’s reflection. The proposed method has the potential for high-throughput fabrication of patterned Si wafer, and the low reflectivity allows the application of these wafers in crystalline silicon solar cells.

Research and Development of Universal Equipment for Geological Hazard Monitoring and Early Warning

2020 ◽  
Author(s):  
Juan Ma ◽  
Mingzhi Zhang ◽  
Gan Qi ◽  
Gloria Xing ◽  
Zack Huang
Keyword(s):  
Early Warning ◽  
Field Tests ◽  
Cost Effective ◽  
Impact Factors ◽  
Geological Hazard ◽  
Sensing Technology ◽  
Disaster Monitoring ◽  
Adaptation Scenarios ◽  
Monitoring And Early Warning

&lt;p&gt;Hilly and mountainous areas account for 65% of the total land area in China. There were 286,708 potential geological hazard sites registered at the end of 2018, among which 276,600 were small-and medium-sized. Small and medium geological hazards are a priority in geological disaster prevention. However, due to their large number and the high prices of professional monitoring equipment, it is difficult to find a cost-effective and accurate monitoring technology, method, or means for their long-term disaster monitoring. To this end, this paper aims to explore a reliable, cost-effective, precise, easily installable, low-power solution for small and medium geological hazard monitoring and early warning, centring on characteristic quantities such as deformation before collapse, landslides, and other disasters, and some key impact factors such as rainfall, moisture content, stress, and displacement velocity. Using universal &amp;#160;equipment&amp;#160;based on microelectromechanical sensing technology and narrowband IoT technology, laboratory simulations and field tests were performed to research the equipment in terms of adaptation scenarios, effective monitoring ranges, installation methods and locations, and normalization of data reporting content, thus setting up a scientific method for small and medium geological hazard monitoring and early warning.&lt;/p&gt;

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