scholarly journals Avalanche effect for chemically modified dust mitigation from surfaces

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Johnny Ebaika Adukwu ◽  
Bekir Sami Yilbas ◽  
Almaz Jalilov ◽  
Hussain Al-Qahtani ◽  
Ahmet Z. Sahin ◽  
...  

AbstractCost effective dust mitigation from surfaces is one of the challenges in various sectors. The reduction of dust adhesion on surfaces plays a vital role for dust mitigation from surfaces under the gravitational influence. Creating an avalanche effect on dusty surfaces improves the dust mitigation rate and provides an effective cleaning process. Hence, solution treatment of dust by low concentration hydrofluoric acid is considered towards reducing dust adhesion on glass surfaces. To increase the rate of dust mitigation, the avalanche influence is created by the higher density and larger size particles (5300 kg/m3 and ~ 50 µm) than the average size dust particles (2800 kg/m3 and 1.2 µm) via locating them in the top region of the dusty glass surfaces. Mitigation velocity of the dust particles is evaluated using a high-speed recording system and the tracker program. Findings revealed that solution treatment (curing) of the dust particles results in the formation of fluorine compounds, such as CaF2 and MgF2, on dust surfaces, which suppress dust adhesion on surfaces. OSHA Globally Harmonized System lists the fluorine compounds formed as environmentally non-harmful. Avalanche's influence results in dust mitigation at a smaller tilt angle of the glass surface (~ 52°) than that of the case with none-avalanche influence (63°). Area cleaned on the glass surface, via dust mitigation, is larger as the avalanche is introduced, which becomes more apparent for the solution treated dust particles. Dust mitigation under avalanche influence improves optical transmittance of the dusty glass samples by a factor of 98%.

RSC Advances ◽  
2018 ◽  
Vol 8 (59) ◽  
pp. 33775-33785 ◽  
Author(s):  
Bekir Sami Yilbas ◽  
Abdullah Al-Sharafi ◽  
Haider Ali ◽  
Nasser Al-Aqeeli ◽  
Hussain Al-Qahtani ◽  
...  

The removal of environmental dust particles from optically transparent glass surfaces is considered, and the dynamics of the dust particles on the inclined hydrophobic glass surface is examined.


RSC Advances ◽  
2017 ◽  
Vol 7 (47) ◽  
pp. 29762-29771 ◽  
Author(s):  
Bekir Sami Yilbas ◽  
Muhammad Rizwan Yousaf ◽  
Abdullah Al-Sharafi ◽  
Haider Ali ◽  
Fahad Al-Sulaiman ◽  
...  

The behavior of environmental dust particles on a silicone oil impregnated glass surface is examined in relation to optical transparent surfaces for self-cleaning applications.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Abba Abdulhamid Abubakar ◽  
Bekir Sami Yilbas ◽  
Hussain Al-Qahtani ◽  
Ammar Alzaydi

Abstract Dust repelling from transparent polyvinyl chloride film surface via sonic excitation is examined and dynamics of repelled (inflight) dust particles are analyzed. An experimental rig is designed and built to assess the vibrational characteristics of the polyvinyl chloride film at different frequencies of sonic excitation. A high speed recording system and tracking program are utilized monitoring and evaluating the dynamics of the inflight particles. The dynamics of inflight particles are also simulated numerically and the predictions are compared with those of the experimental data. In order to examine the influence of dust particle adhesion on the dynamics of the inflight particles, the polyvinyl chloride film surface is hydrophobized through dip coating by functionalized nano-silica particles. Improvement of the optical transmittance of the dust mitigated film is determined via outdoor tests. The findings demonstrate that sonic excitation repels the particles from the film surface and it is more pronounced at 64 Hz excitation frequency while demonstrating that sonic excitation can be used for dust removal from transparent surfaces. The mitigation via sonic excitation improves the optical transmittance of the dusty surface by 77%, which becomes more apparent for hydrophobic surfaces.


Author(s):  
Mark Kimball

Abstract This article presents a novel tool designed to allow circuit node measurements in a radio frequency (RF) integrated circuit. The discussion covers RF circuit problems; provides details on the Radio Probe design, which achieves an input impedance of 50Kohms and an overall attenuation factor of 0 dB; and describes signal to noise issues in the output signal, along with their improvement techniques. This cost-effective solution incorporates features that make it well suited to the task of differential measurement of circuit nodes within an RF IC. The Radio Probe concept offers a number of advantages compared to active probes. It is a single frequency measurement tool, so it complements, rather than replaces, active probes.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Hitesh Agarwal ◽  
Bernat Terrés ◽  
Lorenzo Orsini ◽  
Alberto Montanaro ◽  
Vito Sorianello ◽  
...  

AbstractElectro-absorption (EA) waveguide-coupled modulators are essential building blocks for on-chip optical communications. Compared to state-of-the-art silicon (Si) devices, graphene-based EA modulators promise smaller footprints, larger temperature stability, cost-effective integration and high speeds. However, combining high speed and large modulation efficiencies in a single graphene-based device has remained elusive so far. In this work, we overcome this fundamental trade-off by demonstrating the 2D-3D dielectric integration in a high-quality encapsulated graphene device. We integrated hafnium oxide (HfO2) and two-dimensional hexagonal boron nitride (hBN) within the insulating section of a double-layer (DL) graphene EA modulator. This combination of materials allows for a high-quality modulator device with high performances: a ~39 GHz bandwidth (BW) with a three-fold increase in modulation efficiency compared to previously reported high-speed modulators. This 2D-3D dielectric integration paves the way to a plethora of electronic and opto-electronic devices with enhanced performance and stability, while expanding the freedom for new device designs.


Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3137
Author(s):  
Shuguang Guan ◽  
Qiaoli Pu ◽  
Yinan Liu ◽  
Honghong Wu ◽  
Wenbo Yu ◽  
...  

Crocins are highly valuable natural compounds for treating human disorders, and they are also high-end spices and colorants in the food industry. Due to the limitation of obtaining this type of highly polar compound, the commercial prices of crocins I and II are expensive. In this study, macroporous resin column chromatography combined with high-speed counter-current chromatography (HSCCC) was used to purify crocins I and II from natural sources. With only two chromatographic steps, both compounds were simultaneously isolated from the dry fruit of Gardenia jasminoides, which is a cheap herbal medicine distributed in a number of countries. In an effort to shorten the isolation time and reduce solvent usage, forward and reverse rotations were successively utilized in the HSCCC isolation procedure. Crocins I and II were simultaneously obtained from a herbal resource with high recoveries of 0.5% and 0.1%, respectively, and high purities of 98.7% and 99.1%, respectively, by HPLC analysis. The optimized preparation method was proven to be highly efficient, convenient, and cost-effective. Crocins I and II exhibited inhibitory activity against ATP citrate lyase, and their IC50 values were determined to be 36.3 ± 6.24 and 29.7 ± 7.41 μM, respectively.


Author(s):  
Zai-Wei Li ◽  
Xiao-Zhou Liu ◽  
Hong-Yao Lu ◽  
Yue-Lei He

The deformation of longitudinally coupled prefabricated slab track (LCPST) due to high temperature may lead to a reduction in ride comfort and safety in high-speed rail (HSR) operation. It is thus critical to understand and track the development of such defects. This study develops an online monitoring system to analyze LCPST deformation at different slab depths under various temperatures. The trackside system, powered by solar energy with STM8L core that is ultra-low in energy consumption, is used to collect data of LCPST deformation and temperature level uninterruptedly. With canonical correlation analysis, it is found that LCPST deformation presents similar periodic variation to yearly temperature fluctuation and large longitudinal force may be generated as heat accumulates in summer, thereby causing track defects. Then the distribution of temperature and deformation data is categorized based on fuzzy c-means clustering. Through the distribution analysis, it is suggested that slab inspection can be shortened to 6 hours, i.e. from 10:00 am to 4:00 pm, reducing 14.3% track inspection workload from the current practice. The price of workload reduction is only a 2% chance of missed detection of slab deformation. The finding of this research can be used to enhance LCPST monitoring efficiency and reduce interruption to HSR operation, which is an essential step in promoting reliable and cost-effective track service.


2017 ◽  
Vol 867 ◽  
pp. 290-293 ◽  
Author(s):  
Kandasamy Jayakrishna ◽  
P. Sanjay Guar ◽  
R. Senthilkumar ◽  
Nagarajan Aathis

Development of prototypes draws major focus in contemporary manufacturing organisations. Sustainability analysis and comparison of the prototype manufacturing process plays a vital role in deciding the sustainability level of the product. Sustainability of prototyping depends on model building material and model building process. In this paper based on the customer requirements, Environmental Conscious Quality Function Deployment (ECQFD) was carried out. Increased lives, strength, reduced toxicity of material with biodegradability were the major outputs of ECQFD. Cambridge Engineering Selector (CES) and Grey Relation Analysis (GRA) were used for material selection. Wood, ABS, Poly Lactic acid (PLA) and Lead were selected as cost efficient materials for the case product. A CAD model of the case product was developed and subjected to Life Cycle Analysis (LCA) using solid works sustainability express for the above materials. Prototypes of the case products where produced by wood carving, casting, CNC Milling and 3D printing by considering all input parameters required across each process. LCA was conducted using GaBi for the above process and the results were compared. From this study, it was observed that the case product developed using PLA with 3D printing technology had very less impact on environment and is considered as the best and cost effective prototyping method.


2019 ◽  
Vol 7 (1) ◽  
pp. 19-33 ◽  
Author(s):  
Marton Sipos ◽  
Janus Heide ◽  
Daniel E. Lucani ◽  
Morten V. Pedersen ◽  
Frank H.P. Fitzek ◽  
...  

Author(s):  
R Whalley ◽  
M Ebrahimi

A high-speed laminating machine for a fabric coating and conversion process is considered. Following analysis procedures, state-space and the admittance transfer function descriptions for the system are derived. Regulation of the fabric tension owing to heat shrinkage and environmental and coating variations is necessary. An optimum, minimum control effort strategy is proposed, enabling simple cost effective regulation, without the use of active elements. The speed of response of the system is improved by the use of feedback compensation. Design validation, via simulation, obtaining the open- and closed-loop system responses is employed, demonstrating the achievement of smooth, almost monotonic variations in tension following reference changes, as specified.


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