scholarly journals Optimum Multilayer-Graphene-Montmorillonite Composites From Sugar for Thermosolar Coatings Formulations

2017 ◽  
Vol 139 (3) ◽  
Author(s):  
Bàrbara Micó-Vicent ◽  
María López ◽  
Azucena Bello ◽  
Noelia Martínez ◽  
Francisco Martínez-Verdú
Keyword(s):  
Working Conditions ◽  
Low Cost ◽  
Multilayer Graphene ◽  
Optimum Conditions ◽  
Laminar Structure ◽  
Solar Absorptance ◽  
Solar Plant ◽  
Different Temperatures ◽  
Complex Deposition ◽  
Deposition Techniques

Solar thermal coatings are designed to achieve the highest incident solar flux into the receiver of a tower solar plant. These materials are subjected to extreme working conditions of temperature and solar concentrated radiation. Much effort is being made to develop a durable and high absorptive coating that can provide an excellent solar to heat conversion efficiency. Complex deposition techniques (PVD, CVD, electrodeposition, etc.) are developed and tested to achieve solar selectivity. High solar absorptance paints are an alternative technique, that is, easy to apply and implement in the field. In paint, pigments are the compound that provides high absorptance values, whose stability impacts the durability of optical properties. The search for new selective solar pigments for solar receivers is a promising route to improve the efficiency of this technology. In this work, novel nanocomposites were synthesized from low-cost organic materials such as table sugar. Promising results were obtained when intercalated and calcined in the laminar structure of montmorillonite, a type of smectite clay. The pigments were tested in a paint format on metallic coupons at different temperatures to obtain absorptivities above 96% of absorptance after 24 h at 700  °C. Further experiments are still needed to obtain optimum conditions to maximize the coating's absorptivity and durability at high temperature.

scholarly journals Superior Degradation Performance of Nanoporous Copper Catalysts on Methyl Orange

Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 913
Author(s):  
Jinyi Wang ◽  
Sen Yang
Keyword(s):  
Activation Energy ◽  
Methyl Orange ◽  
High Efficiency ◽  
Low Cost ◽  
Degradation Process ◽  
Copper Catalysts ◽  
Reaction Rate Constant ◽  
Nanoporous Structure ◽  
Intra Particle Diffusion ◽  
Different Temperatures

The development of low-cost and high-efficiency catalysts for wastewater treatment is of great significance. Herein, nanoporous Cu/Cu2O catalysts were synthesized from MnCu, MnCuNi, and MnCuAl with similar ligament size through one-step dealloying. Meanwhile, the comparisons of three catalysts in performing methyl orange degradation were investigated. One of the catalysts possessed a degradation efficiency as high as 7.67 mg·g−1·min−1. With good linear fitting by the pseudo-first-order model, the reaction rate constant was evaluated. In order to better understand the degradation process, the adsorption behavior was considered, and it was divided into three stages based on the intra-particle diffusion model. Three different temperatures were applied to explore the activation energy of the degradation. As a photocatalytic agent, the nanoporous structure of Cu/Cu2O possessed a large surface area and it also had low activation energy, which were beneficial to the excellent degradation performance.

Direct Writing on Paper Substrate to Prepare Silver Electrode Structures for Flexible Sensors

2021 ◽  
Vol 21 (12) ◽  
pp. 6048-6053
Author(s):  
Qi Wang ◽  
Mingwei Li ◽  
Yao Xie ◽  
Yun Ou ◽  
Weiping Zhou
Keyword(s):  
Low Cost ◽  
Rapid Development ◽  
Silver Electrode ◽  
Silver Nanostructures ◽  
Direct Writing ◽  
Paper Substrate ◽  
Electronic Products ◽  
Glass Substrates ◽  
Different Temperatures ◽  
Writing Technology

With the rapid development of the electronics industry, electronic products based on silicon and glass substrates electronic products will gradually be unable to meet the rising demand. Flexibility, environmental protection, and low costs are important for the development of electronic products. In this study, an efficient and low-cost method for preparing silver electrode structures by direct writing on paper has been demonstrated. Based on this method, a flexible paper-based sensor was prepared. The liquid printing ink used mainly comprises a precursor liquid without pre-prepared nanomaterials. The precursor liquid is transparent with good fluidity. Simple direct writing technology was used to write on the paper substrate using the precursor ink. When the direct-writing paper substrate was subsequently heated, silver nanostructures precipitated from the precursor liquid ink onto the paper substrate. The effect of different temperatures on the formation of the silver nanostructures and the influence of different direct writing processes on the structures were studied. Finally, a paper-based flexible sensor was prepared for finger-bending signal detection. The method is simple to operate and low in cost and can be used for the preparation of environment-friendly paper-based devices.

scholarly journals Prefabricated Urban Underground Utility Tunnels: A Case Study on Mechanical Behaviour with Strain Monitoring and Numerical Simulation

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Yonggang Xiao ◽  
Jubing Zhang ◽  
Jie Cao ◽  
Changhong Li
Keyword(s):  
Numerical Simulation ◽  
Working Conditions ◽  
Failure Modes ◽  
Mechanical Performance ◽  
Low Cost ◽  
Side Wall ◽  
Operating Conditions ◽  
Land Occupation ◽  
Depth Analysis ◽  
Simulation Results

The prefabricated urban utility tunnels (UUTs) have many advantages such as short construction period, low cost, high quality, and small land occupation. However, there is still a lack of in-depth analysis of the mechanical performance of the prefabricated urban utility tunnel (UUT) structure with bolted connections under different working conditions. In this paper, the force performance of a prefabricated UUT in Tongzhou District, Beijing, was studied under different working conditions using two methods: field monitoring and numerical simulation. The multichannel strain monitor was used for monitoring, and the internal wall concrete and bolt strain change data under the two conditions of installation and backfill were obtained. Combined with the construction process of the UUTs, a three-dimensional numerical model was established by COMSOL, where the build-in bolt assembly was used to simulate the longitudinal connection of the tunnel. The simulation results were compared with the measured data to verify the rationality of the computational model. The simulation results showed that the concrete and bolts on the inner wall of the tunnel work well under the two conditions of installation and backfilling; The deformation of the top plate of the prefabricated tunnel was approximately parabolic, with the largest vertical displacement (0.37 mm) in the middle and the most sensitive to the vertical load in the central part of the roof. The central portion of the side wall had the largest displacement (0.17 mm) in the inner concave. The tensile stress of bolt 3 increased the most (30.75 MPa) but was still much smaller than the yield strength of the bolt. The concrete and bolts of the UUT were found to work well through force analysis under operating conditions. In conclusion, analysis of structural forces and deformation failure modes will help design engineers understand the basic mechanisms and select the appropriate UUT structure.

scholarly journals Ethical Issues in Global Supply Chains

2007 ◽  
Author(s):  
Bodo B. Schlegelmilch ◽  
Magdalena Öberseder
Keyword(s):  
Supply Chain ◽  
Supply Chains ◽  
Working Conditions ◽  
Ethical Issues ◽  
Low Cost ◽  
Global Supply Chains ◽  
Unethical Conduct ◽  
Production Methods ◽  
Technological Advances ◽  
Consumer Demands

Despite all technological advances, global supply chains are always based on the interaction of people. And wherever people interact, a kaleidoscope of ethical issues emerges. While consumer demands and concerns have undoubtedly led to an increased awareness of unethical conduct in the supply chain, contravening forces, such as the relentless pressures for low cost products and the ease by which consumers are purchasing non-deceptive counterfeits, should also not be ignored. Many retailers are now embracing ethical issues by emphasising, for example, that they take care of the production methods and working conditions pertaining to the goods they offer.

scholarly journals A Novel Robotic Arm Design for Small Scale Industries Using myRIO

2018 ◽  
Vol 7 (4.6) ◽  
pp. 257
Author(s):  
M. Srilatha ◽  
R. Hemalatha
Keyword(s):  
Working Conditions ◽  
Raw Materials ◽  
Technological Development ◽  
Low Cost ◽  
Robotic Arm ◽  
Small Scale ◽  
Starting Point ◽  
Complete Automation ◽  
Human Effort ◽  
Small Scale Industries

In small-scale industries, under extreme working conditions, personnel are frequently involved in lifting and carrying raw materials, which is hazardous at times. Robot, a machine with intelligence can perform the same task with the help of control instructions fed by computer or remote control. Technological development in the area of robotics made it possible to design robotic arm with the same degree of precision as a replacement to the human intervention. This will introduce automation in small-scale industries, which saves time, reduces human effort and expenditure in production. Further, this will be a starting point for complete automation of entire process, which can be expensive and complicated. NI LabVIEW along with NI-myRIO can provide a better solution in designing a more precise and accurate robot in a very low cost, which is affordable by small-scale industries. NI-myRIO is used to generate and acquire signals for controlling and processing. Further it has an inbuilt processor and FPGA which has many reconfigurable analogue and digital features.  

Recent Progress in Disposable Ion-Selective Sensors for Environmental Applications

2012 ◽  
Vol 77 ◽  
pp. 65-70 ◽  
Author(s):  
Giusy Matzeu ◽  
Claudio Zuliani ◽  
Dermot Diamond
Keyword(s):  
Film Thickness ◽  
Recent Progress ◽  
Low Cost ◽  
Contact Layer ◽  
Ion Selective Electrodes ◽  
Complex Relationship ◽  
Solid Contact ◽  
Materials Used ◽  
Deposition Techniques

Solid-contact Ion Selective Electrodes (SC-ISEs) for the detection of lead are prepared on screen printed substrates in order to have low-cost and disposable sensors which may be useful in long-term environmental monitoring. It is shown that the materials used as solid contact layer, the deposition techniques and their thickness affect greatly the performances of the sensors. Poly(3-octylthiophene-2,5-diyl) (POT) and poly-3,4-ethylenedioxithiophene (PEDOT) are employed in this investigation. A trend showing an optimum is found for sensors prepared with POT as the batch reproducibility depends on the amount drop-cast, i.e., thickness. In case of PEDOT which is grown amperometrically the trend is more complex but an optimum for the batch reproducibility is again found depending on the current density. In the latter case, the film thickness and the overoxidation degree of the polymer probably concur in determining a more complex relationship.

Localized Corrosion of UNS A95052 Aluminum Alloy for Application in Multi-Effect Desalinator Plants

CORROSION ◽  
10.5006/2815 ◽  
2018 ◽  
Vol 74 (9) ◽  
pp. 1023-1032
Author(s):  
Dannisa R. Chalfoun ◽  
Mariano A. Kappes ◽  
Mauricio Chocrón ◽  
Raul B. Rebak
Keyword(s):  
Aluminum Alloy ◽  
Crevice Corrosion ◽  
Low Cost ◽  
Localized Corrosion ◽  
Complete Evaluation ◽  
Electrochemical Tests ◽  
Metal Plates ◽  
Different Temperatures ◽  
Partially Occluded ◽  
Desalination Plants

Aluminum alloy UNS A95052 (AA5052) is very attractive for desalination applications because of its good corrosion resistance in seawater at temperatures up to 125°C, low cost, good thermal conductivity, and non-toxicity of its corrosion products. The pitting corrosion potential, Epit, and the pit repassivation potential, Er,pit, of AA5052 were measured in deaerated 65,000 ppm sodium chloride (NaCl) solutions at 30°C, 60°C, and 85°C. Epit decreased with temperature, in accord with literature results. Er,pit was a function of anodic charge passed during pit growth stage. A complete evaluation of suitability of this alloy from a corrosion perspective requires also studies of crevice corrosion at different temperatures, considering that multi-plate designs of desalinators have metal plates in contact with rubber gaskets and seals. Cyclic potentiodynamic polarization was used to estimate crevice repassivation potentials, Er,crev, at 30°C, 60°C, and 85°C, in specimens with an attached rubber O-ring as a crevice former. This crevice former simulated the partially occluded geometry expected in desalination plants. Stable crevice corrosion potentials, Ecrev, were similar to Epit, and, when polarized to a similar anodic charge density, Er,crev were similar to Er,pit. Based on this result, from a corrosion perspective, the presence of crevices in the desalination plant is not expected to present an additional risk during operation of the plant. Electrochemical tests were also performed in saturated AlCl3 solutions to explain the results using Galvele’s localized acidification model.

scholarly journals Sustainable Organic Dyes from Winemaking Lees for Photoelectrochemical Dye-Sensitized Solar Cells

2020 ◽  
Vol 10 (6) ◽  
pp. 2149
Author(s):  
Manuel Meneghetti ◽  
Aldo Talon ◽  
Elti Cattaruzza ◽  
Emilio Celotti ◽  
Elisabetta Bellantuono ◽  
...  
Keyword(s):  
Solar Cells ◽  
Organic Dyes ◽  
Low Cost ◽  
Dye Sensitized Solar Cells ◽  
Cost Effective ◽  
Simulated Solar Light ◽  
Dye Sensitized ◽  
Different Temperatures ◽  
Conversion Efficiencies ◽  
Sensitized Solar Cells

During the last two decades, Dye Sensitized Solar Cells (DSSCs) have received a great deal of attention as a promising, low-cost alternative to conventional silicon photovoltaic devices. Natural dye molecules can be used as a sensitizer for their low cost, good light absorbance, easy preparation process, and biodegradability. In this study, dyes were obtained from wine lees, the last by-product of winemaking process, supplied by a venetian winery (Italy). Polyphenols, like tannins and anthocyanins, which were extracted from winemaking lees, were adsorbed on a nanostructured ordered mesoporous titanium dioxide, previously treated at different temperatures (400–600 °C). Both dyes and titania semiconductor samples were studied with different techniques. The tests were carried out on prototypes to evaluate the cell power and the photocurrent generated under simulated solar light irradiation. The obtained solar energy conversion efficiencies are comparable to those that were reported in literature by using organic dyes extracted from vegetables, fruits, and plants. It is significant that these dyes are largely available and cost effective, since recovered from a waste otherwise to be disposed of, opening up a perspective of feasibility for inexpensive and environmentally friendly dye solar cells to generate green electricity and transforming agri-food waste into a resource.

Adsorption kinetics and isotherms of bioactive antioxidant quercetin onto amino-functionalized silica nanoparticles in aqueous ethanol solutions

2017 ◽  
Vol 41 (16) ◽  
pp. 8451-8458 ◽  
Author(s):  
Masoud Ghanimati ◽  
Morteza Jabbari ◽  
Ali Farajtabar ◽  
Sayyed Ahmad Nabavi-Amri
Keyword(s):  
Silica Nanoparticles ◽  
Rice Husk ◽  
Adsorption Kinetics ◽  
Aqueous Ethanol ◽  
Low Cost ◽  
Acid Leaching ◽  
Functionalized Silica ◽  
Different Temperatures ◽  
Kinetics And Isotherms ◽  
Functionalized Silica Nanoparticles

Nano-structural particles of silica were synthesized from low-cost rice husk by acid leaching and further annealing at different temperatures.

Development of a Low Cost Device for Measuring Solar Irradiance

2012 ◽  
Vol 457-458 ◽  
pp. 1377-1382
Author(s):  
Yu Jie Chen ◽  
Cong Hu ◽  
Yi Ze Sun ◽  
Zhuo Meng
Keyword(s):  
Solar Irradiance ◽  
Low Cost ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Solar Irradiation ◽  
Photoelectric Cell ◽  
Cost System ◽  
Different Temperatures ◽  
The Cost

For a determination of the system’s efficiency and decrease the cost, a low cost system for measuring solar irradiance is designed. By analyzing the influence of solar irradiance and temperature to solar cell, we have found that in case of different temperatures the variation of short-circuit current (Isc) in function of solar irradiation incident (E) is always linear. Then the read-out circuitry is designed to measure and convert the signal which is detected by the photoelectric cell and thermocouples. At last, the software is developed to compensate the temperature and make sure the device work normally. The results of detecting the system show that it’s effective and reliable.

Sign in / Sign up

Export Citation Format

Share Document