scholarly journals Development of Warm In-Place Recycling Technique as an Eco-Friendly Asphalt Rehabilitation Method

2021 ◽  
Vol 6 (7) ◽  
pp. 101
Author(s):  
Byungkyu Moon ◽  
Ashkan Bozorgzad ◽  
Hosin (David) Lee ◽  
Soo-Ahn Kwon ◽  
Kyu-Dong Jeong ◽  
...  
Keyword(s):  
Heating Temperature ◽  
Low Cost ◽  
Compact Tension ◽  
Milling Process ◽  
Infrared Heating ◽  
Moisture Susceptibility ◽  
Fine Aggregates ◽  
Low Temperature Cracking ◽  
Different Temperatures ◽  
Recycling Technique

Cold In-place Recycling (CIR) has been widely used in the world since it is easy to apply it in the field at a low cost. However, it is not normally used as a surface layer as a result of its inconsistent quality due to an excessive amount of fine aggregates pulverized during the milling process. Hot In-place Recycling (HIR) can retain the original shape of the aggregates, but it often produces a large amount of Volatile Organic Compounds (VOCs). Therefore, a third in-place recycling technique is introduced in this paper: Warm In-place Recycling (WIR). The WIR technique overcomes the limitations of both CIR and HIR techniques by lowering a heating temperature while adding a Tetraethylenepentamine (TEPA)/Soybean/SBS additive. To identify the effect of the additive on the RTFO-aged binder, viscosity and dynamic modulus values were measured at different temperatures. Based on Hamburg Wheel Tracking (HWT) and Disc-Shaped Compact Tension (DCT) tests, the additive improved the moisture susceptibility and low temperature cracking resistance. The indirect infrared heating equipment reduced the emission by lowering the pavement surface heating temperature by 20 °C from 140 to 120 °C. Compared with the heating at 140 °C, the LPG usage for heating at 140 °C was lowered by 21%. The proposed WIR equipment with an additive would revolutionize the in-place recycling practices.

Heat Treatment Influence on the Corrosion Resistance of a Cu-Al-Fe-Mn Bronze

2018 ◽  
Vol 69 (5) ◽  
pp. 1055-1059 ◽  
Author(s):  
Mariana Ciurdas ◽  
Ioana Arina Gherghescu ◽  
Sorin Ciuca ◽  
Alina Daniela Necsulescu ◽  
Cosmin Cotrut ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Corrosion Resistance ◽  
Structural Changes ◽  
Heating Temperature ◽  
Galvanic Corrosion ◽  
Cooling Water ◽  
Open Circuit ◽  
Water Quenching ◽  
Heat Treated ◽  
Different Temperatures

Aluminium bronzes are exhibiting good corrosion resistance in saline environments combined with high mechanical properties. Their corrosion resistance is obviously confered by the alloy chemical composition, but it can also be improved by heat treatment structural changes. In the present paper, five Cu-Al-Fe-Mn bronze samples were subjected to annealing heat treatments with furnace cooling, water quenching and water quenching followed by tempering at three different temperatures: 200, 400 and 550�C. The heating temperature on annealing and quenching was 900�C. The structure of the heat treated samples was studied by optical and scanning electron microscopy. Subsequently, the five samples were submitted to corrosion tests. The best resistance to galvanic corrosion was showed by the quenched sample, but it can be said that all samples are characterized by close values of open-circuit potentials and corrosion potentials. Concerning the susceptibility to other types of corrosion (selective leaching, pitting, crevice corrosion), the best corrosion resistant structure consists of a solid solution, g2 and k compounds, corresponding to the quenched and 550�C tempered sample.

scholarly journals Design and Manufacturing of a Disposable, Cyclo-Olefin Copolymer, Microfluidic Device for a Biosensor †

Sensors ◽  
2019 ◽  
Vol 19 (5) ◽  
pp. 1178 ◽  
Author(s):  
Jorge Prada ◽  
Christina Cordes ◽  
Carsten Harms ◽  
Walter Lang
Keyword(s):  
Microfluidic Device ◽  
Heating Temperature ◽  
Low Cost ◽  
Reaction Chamber ◽  
Microfluidic System ◽  
Heating Process ◽  
Design And Manufacturing ◽  
On Chip ◽  
Working Parameters ◽  
Auto Fluorescence

This contribution outlines the design and manufacturing of a microfluidic device implemented as a biosensor for retrieval and detection of bacteria RNA. The device is fully made of Cyclo-Olefin Copolymer (COC), which features low auto-fluorescence, biocompatibility and manufacturability by hot-embossing. The RNA retrieval was carried on after bacteria heat-lysis by an on-chip micro-heater, whose function was characterized at different working parameters. Carbon resistive temperature sensors were tested, characterized and printed on the biochip sealing film to monitor the heating process. Off-chip and on-chip processed RNA were hybridized with capture probes on the reaction chamber surface and identification was achieved by detection of fluorescence tags. The application of the mentioned techniques and materials proved to allow the development of low-cost, disposable albeit multi-functional microfluidic system, performing heating, temperature sensing and chemical reaction processes in the same device. By proving its effectiveness, this device contributes a reference to show the integration potential of fully thermoplastic devices in biosensor systems.

scholarly journals Performance and Microstructure of Cold Recycled Mixes Using Asphalt Emulsion with Different Contents of Cement

Materials ◽  
2019 ◽  
Vol 12 (16) ◽  
pp. 2548 ◽  
Author(s):  
Yanhai Yang ◽  
Ye Yang ◽  
Baitong Qian
Keyword(s):  
Low Temperature ◽  
Temperature Stability ◽  
Hydration Products ◽  
High Temperature Stability ◽  
Asphalt Emulsion ◽  
Moisture Susceptibility ◽  
Pavement Maintenance ◽  
Maintenance And Rehabilitation ◽  
Low Temperature Cracking ◽  
Temperature Crack

Cold recycled mixes using asphalt emulsion (CRME) is an economical and environmentally-friendly technology for asphalt pavement maintenance and rehabilitation. In order to determine the optimum range of cement contents, the complex interaction between cement and asphalt emulsion and the effects of cement on performance of CRME were investigated with different contents of cement. The microstructure and chemical composition of the fracture surface of CRME with different contents of cement were analyzed in this paper as well. Results show that the high-temperature stability and moisture susceptibility of CRME increased with the contents of cement increasing. The low-temperature crack resistance ability gradually increased when the content of cement is increased from 0% to 1.5%. However, it gradually decreased when the content of cement is increased from 1.5% to 4%. Cold recycled mixes had better low-temperature cracking resistance when the contents of cement were in the range from 1% to 2%. The results of microstructure and energy spectrum analysis show that the composite structure is formed by hydration products and asphalt emulsion. The study will be significant to better know the effects of cement and promote the development of CRME.

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.

Synthesis, Photoluminescence and Bio-Targeting Applications of Blue Graphene Quantum Dots

2016 ◽  
Vol 16 (4) ◽  
pp. 3457-3467 ◽  
Author(s):  
Jigang Wang ◽  
Ji Zhou ◽  
Wenhua Zhou ◽  
Jilong Shi ◽  
Lun Ma ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Graphene Oxide ◽  
Sodium Hydroxide ◽  
Heating Temperature ◽  
Thin Sheet ◽  
Graphene Quantum Dots ◽  
Photoluminescence Intensity ◽  
Cytotoxic Effects ◽  
Different Temperatures ◽  
Blue Photoluminescence

Chemical derived graphene oxide, an atomically thin sheet of graphite with two-dimensional construction, offers interesting physical, electronic, thermal, chemical, and mechanical properties that are currently being explored for advanced physics electronics, membranes, and composites. Herein, we study graphene quantum dots (GQD) with the blue photoluminescence under various parameters. The GQD samples were prepared at different temperatures, and the blue photoluminescence intensity of the solution improved radically as the heating temperatures increased. Concerning PL peak and intensity of the quantum dots, the results demonstrated dependence on time under heating, temperature of heating, and pH adjusted by the addition of sodium hydroxide. After hydrothermal synthesis routes, the functional groups of graphene oxide were altered the morphology showed the stacking configuration, and self-assembled structure of the graphene sheets with obvious wrinkles appeared at the edge structures. In addition, absorption, PL, and PLE spectra of the graphene quantum dots increase with different quantities of sodium hydroxide added. Finally, using GQD to target PNTIA cells was carried out successfully. High uptake efficiency and no cytotoxic effects indicate graphene quantum dots can be suitable for bio-targeting.

Morphology of Edge Cracks of Rolled Magnesium Alloy Sheet

2014 ◽  
Vol 922 ◽  
pp. 469-474 ◽  
Author(s):  
Sho Manabe ◽  
Hiroshi Utsunomiya ◽  
Tetsuo Sakai ◽  
Ryo Matsumoto
Keyword(s):  
Magnesium Alloy ◽  
Magnesium Alloys ◽  
High Speed ◽  
Heating Temperature ◽  
Thin Sheet ◽  
Contact Length ◽  
Alloy Sheet ◽  
Different Temperatures ◽  
Edge Cracks ◽  
Critical Reduction

Magnesium alloys show low deformability at low temperature because of hcp structure and inactiveness of basal slip. Manufacturing of thin sheet is difficult in industries. Some approaches, such as small-draft multi-pass rolling, intermediate annealing, isothermal rolling and high-speed rolling were proposed to overcome the deformability. However, small edge cracks are still formed on the sheet. In this study, rolling speed of 1000m/min was employed to warm-roll AZ31B magnesium alloy in a single pass at different temperatures. The edge cracks formed after the rolling were classified into three main groups: minor, regular and zigzag edge cracks. ‘Crack contact length’ are introduced to explain the morphology of edge cracks. The results show that the critical reduction for crack initiation depends on the pre-heating temperature. The spacing between edge cracks increases linearly with the crack contact length regardless of roll diameter, speed and reduction. It is suggested that this approach is useful to understand the formation mechanism of edge cracks and to evaluate the rollability of magnesium alloys.

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 PROPERTIES OF WMA–FOAM MIXES BASED ON MAJOR MECHANICAL TESTS / ŠILTAI MAIŠYTO ASFALTO MIŠINIŲ, GAMINAMŲ PAGAL PUTOTO BITUMO TECHNOLOGIJĄ (WMA-FOAM), SAVYBĖS REMIANTIS PAGRINDINIAIS MECHANINIAIS BANDYMAIS

2011 ◽  
Vol 17 (2) ◽  
pp. 207-216 ◽  
Author(s):  
Amir Kavussi ◽  
Leila Hashemian
Keyword(s):  
Hydrated Lime ◽  
Mechanical Tests ◽  
Moisture Susceptibility ◽  
Adhesion Properties ◽  
Different Temperatures ◽  
Indirect Tensile ◽  
Lime Powder ◽  
Marshall Stability ◽  
Wheel Tracking ◽  
Lower Production

One of the main advantages of warm mix asphalt (WMA) used as an alternative to conventional hot mix asphalt (HMA), is to reduce mixing and compaction temperatures. This laboratory study was conducted with the aim of determining physical properties of WMA mixes produced using foam bitumen technology (WMA–Foam), while applying different mixing and compaction temperatures. The effect of laboratory compaction method on mix properties was also investigated. WMA–Foam mixes were produced, adding a soft bitumen to coarse aggregate particles at the first stage, then a hard bitumen, transformed into foam bitumen using a laboratory foam making device, was directly added to aggregates at the next stage. Compaction was performed separately applying both Marshall and gyratory compactors (GC) at different temperatures. Marshall Stability and void contents of the samples were determined as two major parameters for characterizing WMA–Foam mixes. Moisture susceptibility and rutting potential of WMA–Foam samples were evaluated using indirect tensile strength (ITS) and wheel tracking tests. In addition, separate samples were prepared, in which hydrated lime powder was added as an anti-stripping agent to improve adhesion properties of the mixes. Comparing the results of WMA–Foam mixes with control HMA of the same content, resulted in mixes with similar properties of the control HMA, with appreciably lower production and compaction temperatures of the former. It was also resulted that mixes compacted with gyratory compactor were less sensitive to temperature variations than those compacted with Marshall Hammer. Santrauka Pagrindinis šiltai maišyto asfalto mišinių privalumas, lyginant su įprastiniais karštai maišyto asfalto mišiniais, yra galimybė sumažinti asfalto mišinio maišymo ir tankinimo temperatūras. Šio laboratorinio tyrimo tikslas – nustatyti šiltai maišyto asfalto mišinių, gaminamų pagal putoto bitumo technologiją (WMA-Foam), fizines savybes taikant skirtingas maišymo ir tankinimo temperatūras. Taip pat buvo tirtas skirtingų laboratorinių tankinimo metodų poreikis asfalto mišinio savybėms. WMA-Foam technologijos mišiniai gaminti pirmame etape į stambiąsias mineralines medžiagas dedant minkštąjį bitumą, o kitame etape – kietajį bitumą specialiu laboratoriniu putojimo įrenginiu pavertus putotu bitumu dedant į pirmame etape paruoštas mineralines medžiagas. Tankinta atskirai Maršalo plūktuvu ir giratoriaus presu skirtingose mišinio temperatūrose. Maršalo bandinių pastovumas ir oro tuštumų skaičius buvo nustatyti kaip du pagrindiniai WMA-Foamtechnologijos mišinius charakterizuojantys parametrai. WMA-Foam technologijos bandinių jautrumas vandeniui ir atsparumas provėžų susidarymui buvo vertinti pagal netiesioginio tempimo jėgos ir rato riedėjimo vėžės nustatymo bandymus. Keletas bandinių papildomai buvo pagaminti su gesintosiomis kalkėmis, t. y. asfalto mišinio sukibimą gerinančiu priedu. Lyginant WMA-Foam technologijos ir karštai maišyto asfalto mišinių bandymų rezultatus nustatyta, kad identiškos sudėties WMA-Foam technologijos mišinių savybės yra panašios į karštai maišyto asfalto mišinių savybes, tačiau jos pasiekiamos pastebimai žemesnėse maišymo ir tankinimo temperatūrose. Taip pat nustatyta, kad asfalto mišinio bandiniai, pagaminti giratoriaus presu, buvo ne tokie jautrūs gamybos temperatūros kitimui, lyginant su bandiniais, pagamintais Maršalo plūktuvu.

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.

The Effect of Heating Temperature on Total Phenolic Content, Antioxidant Activity, and Phenolic Compounds of Plum and Mahaleb Fruits

2019 ◽  
Vol 15 (11-12) ◽  
Author(s):  
Kashif Ghafoor ◽  
Isam A. Mohamed Ahmed ◽  
Süleyman Doğu ◽  
Nurhan Uslu ◽  
Gbemisola J. Fadimu ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Phenolic Compounds ◽  
Gallic Acid ◽  
Total Phenolic Content ◽  
Phenolic Content ◽  
Heating Temperature ◽  
Dry Weight ◽  
Total Phenolic ◽  
Dihydroxybenzoic Acid ◽  
Different Temperatures

AbstractThe effect of heating at different temperatures (60, 80, 90, 110, and 130 °C) on the total phenolic content, antioxidant activity, and phenolic compounds present in plum and mahaleb fruits was investigated. The antioxidant activity values and total phenolic contents of fresh plum (93.82% measured by DPPH method, 787.79 mg gallic acid equivalent (GAE)/100 g dry weight determined by Folin method) and mahaleb fruits (81.80%, 634.47 mg GAE/100 g dry weight) were higher than plum and mahaleb fruits dried at different temperatures (p < 0.05). Generally, the heating process caused a reduction in both total phenolic content and antioxidant activity for plum and mahaleb. While (+)-catechin (92.62 mg/kg), 1,2-dihydroxybenzene (132.15 mg/kg), gallic acid (107.01 mg/kg), and 3,4-dihydroxybenzoic acid (74.59 mg/kg) are the key phenolic compounds in fresh plum, (+)-catechin, 3,4-dihydroxybenzoic acid, 1,2-dihydroxybenzene, and syringic and caffeic acids were the major phenolic compounds of mahaleb fruits. The polyphenol content of fruits and the class of phenolics present are significantly affected by heating temperature.

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