Influence of Mercerization Process on the Surface of Coconut Fiber for Composite Reinforcement

2020 ◽  
Vol 1012 ◽  
pp. 37-42
Author(s):  
Géssica da Silva Nicolau ◽  
Ricardo Pondé Weber ◽  
Sergio Neves Monteiro ◽  
Gabriela Azevedo Loureiro ◽  
Amanda Assis Lavinsky ◽  
...  

The high consumption of green coconut water, especially in tropical countries like Brazil, generates an aggravating factor to the environment, which is associated with the waste generated after its consumption. Thus, one of the possible ways of reusing the coconut shell after consumption is through the extraction of its fibers, which are considered for several applications. In general, natural lignocellulosic fibers (NLFs) have been used for many purposes, such as reinforcement filler in composite materials, since they have low cost and good mechanical properties. With the intention of providing a better compatibility between the NLFs and the composite polymeric matrix, different types of surface treatments are carried out on the fibers, including mercerization, a chemical treatment in which a basic solution is used. In this sense, the present work aims to verify the influence of mercerization with 3% sodium hydroxide (NaOH) on coconut fiber. Among the analyses carried out, stands the scanning electron microscope (SEM) on fresh and treated coconut fibers. The SEM analyses, allowed to observe that after treatment via mercerization, the fibers displayed a greater surface roughness. This indicates the partial removal of lignin, hemicellulose and some other extracts present on the outer layer of the coconut fiber. Therefore, mercerization will probably enable a better mechanical anchoring between fiber and matrix. Results obtained suggest the effectiveness of the mercerization process. However, it was also of concern that such treatment tends to generate NaOH residues, which is a negative factor regarding sustainability.

2021 ◽  
pp. 088391152199784
Author(s):  
Nipun Jain ◽  
Shashi Singh

Development of an artificial tissue by tissue engineering is witnessed to be one of the long lasting clarified solutions for the damaged tissue function restoration. To accomplish this, a scaffold is designed as a cell carrier in which the extracellular matrix (ECM) performs a prominent task of controlling the inoculated cell’s destiny. ECM composition, topography and mechanical properties lead to different types of interactions between cells and ECM components that trigger an assortment of cellular reactions via diverse sensing mechanisms and downstream signaling pathways. The polysaccharides in the form of proteoglycans and glycoproteins yield better outcomes when included in the designed matrices. Glycosaminoglycan (GAG) chains present on proteoglycans show a wide range of operations such as sequestering of critical effector morphogens which encourage proficient nutrient contribution toward the growing stem cells for their development and endurance. In this review we discuss how the glycosylation aspects are of considerable importance in everyday housekeeping functions of a cell especially when placed in a controlled environment under ideal growth conditions. Hydrogels made from these GAG chains have been used extensively as a resorbable material that mimics the natural ECM functions for an efficient control over cell attachment, permeability, viability, proliferation, and differentiation processes. Also the incorporation of non-mammalian polysaccharides can elicit specific receptor responses which authorize the creation of numerous vigorous frameworks while prolonging the low cost and immunogenicity of the substance.


2013 ◽  
Vol 756-759 ◽  
pp. 489-492
Author(s):  
Fu Lu Jin ◽  
Yun Peng Li ◽  
Hong Rui Wang

To automatic test the function and performance of an airborne radar, changeable test adapter is adopted to implement the hardware and software design of the automatic test set of the antenna, transceiver and indicator of the radar based on AT89C52. Problems such as t the different types of interfaces, the various kinds of signals and the test of microwave signal are solved successfully and the objectives of resource sharing and automatic test are realized. The test software is designed by modular structure, and with the help of automatic test set hardware, the required test items of the radar system are experimented and the test process control succeeded. Experiment results show that the automatic test set performs steadily and the results meet the requirements of the airborne radar. The set has the advantages of intelligent, manageable and reducing artificial errors. It provides effective guarantees for radars maintenance, fault diagnosis and fault detection, and has a wide application prospect with low cost.


2016 ◽  
Vol 33 (3) ◽  
pp. 167-171 ◽  
Author(s):  
Kazimierz Drabczyk ◽  
Edyta Wróbel ◽  
Grazyna Kulesza-Matlak ◽  
Wojciech Filipowski ◽  
Krzysztof Waczynski ◽  
...  

Purpose The purpose of this study is comparison of the diffusion processes performed using the commercial available dopant paste made by Filmtronics and the original prepared liquid dopant solution. To decrease prices of industrially produced silicon-based solar cells, the new low-cost production processes are necessary. The main components of most popular silicon solar cells are with diffused emitter layer, passivation, anti-reflective layers and metal electrodes. This type of cells is prepared usually using phosphorus oxychloride diffusion source and metal pastes for screen printing. The diffusion process in diffusion furnace with quartz tube is slow, complicated and requires expensive equipment. The alternative for this technology is very fast in-line processing using the belt furnaces as an equipment. This approach requires different dopant sources. Design/methodology/approach In this work, the diffusion processes were made for two different types of dopant sources. The first one was the commercial available dopant paste from Filmtronics and the second one was the original prepared liquid dopant solution. The investigation was focused on dopant sources fabrication and diffusion processes. The doping solution was made in two stages. In the first stage, a base solution (without dopants) was made: dropwise deionized (DI) water and ethyl alcohol were added to a solution consisting of tetraethoxysilane (TEOS) and 99.8 per cent ethyl alcohol. Next, to the base solution, orthophosphoric acid dissolved in ethyl alcohol was added. Findings Diffused emitter layers with sheet resistance around 60 Ω/sq were produced on solar grade monocrystalline silicon wafers using two types of dopant sources. Originality/value In this work, the diffusion processes were made for two different types of dopant sources. The first one was the commercial available dopant paste from Filmtronics and the second one was the original prepared liquid dopant solution.


1994 ◽  
Vol 348 ◽  
Author(s):  
I. Dafinei ◽  
E. Auffray ◽  
P. Lecoq ◽  
M. Schneegans

ABSTRACTIn the quest for low cost scintillators to equip the very large electromagnetic calorimeters for future High Energy Physics experiments, scintillating glasses can offer an attractive alternative to crystals. The expected production price is indeed supposed to be reduced as compared to crystals, especially for very large volumes. An intense R&D effort has been made by the Crystal Clear collaboration to develop heavy scintillating fluoride glasses in close collaboration with the industry. Results will be shown on the fluorescence and scintillation properties as well as on the radiation resistance of different types of fluoride glasses. Ideas about possible improvement of present performances will also be given.


2014 ◽  
Vol 12 ◽  
pp. 61-66 ◽  
Author(s):  
Pavol Kajánek

Inertial navigation system (INS) is a self-contained navigation technique. Its main purpose is to determinate the position and the trajectory of the object´s movement in space. This technique is well represented not only as a supplementary method (GPS/INS integrated system) but as an autonomous system for navigation of vehicles and pedestrians, also. The aim of this paper is to design a test for low-cost inertial measurement units. The test results give us information about accuracy, which determine the possible use in indoor navigation or other applications. There are described some methods for processing the data obtained by inertial measurement units, which remove noise and improve accuracy of position and orientation.


Molecules ◽  
2021 ◽  
Vol 26 (21) ◽  
pp. 6684
Author(s):  
Miltiadis Zamparas ◽  
Grigorios L. Kyriakopoulos ◽  
Marios Drosos ◽  
Vasilis C. Kapsalis

The research objective of the study is the estimation of a novel low-cost composite material f-MB (Fe-modified bentonite) as a P and N adsorbent from wastewaters. Τhe present study aimed at examining the phosphate and ammonium removal efficiency from different types of wastewater using f-MB, by conducting bench-scale batch experiments to investigate its equilibrium characteristics and kinetics. The SEM analysis revealed that the platelets of bentonite in f-MB do not form normal bentonite sheets, but they have been restructured in a more compact formation with a great porosity. Regarding the sorption efficiencies (Qm), the maximum phosphate sorption efficiencies (Qm) calculated using the Langmuir model were 24.54, 25.09, 26.13, 24.28, and 23.21 mg/g, respectively, for a pH range of 5 to 9. In addition, the maximum NH4+-N adsorption capacities (Qm) calculated from the Langmuir model were 131.8, 145.7, 168.5, 156.7, and 159.6 mg/g, respectively, for a pH range from 5 to 9. Another important finding of this study is that f-MB can recover P from treated wastewater impacting on resource recovery and circular economy (CE). The modified clay f-MB performed the phosphate and ammonium recovery rates of 80% and 78.5%, respectively. Finally, f-MB can slowly release the largest proportion of phosphate and ammonium ions for a long time, thus extending the application of the f-MB material as a slow-release fertilizer and soil improver.


Author(s):  
Ahmed Falah Hasan ◽  
Ban Ali Kamil

In this paper the effect of different types of bracing had been studied besides studying the effect of height of building. Two different height was studied the first one was a 6-story and 10-story. The studied types of bracing included the V, X, K, and none bracing building. The X bracing is the best type for resist high lateral load,. The building without bracing give maximum story drift and the building may be collapse due to unstability because the lateral load (wind load), the V-bracing give a little different from X-bracing with low cost and easy for construction from X-bracing, and the building is highest the X-bracing is the beast type for bracing.


Author(s):  
Nur Syahirah Amirah Mohd Jopery ◽  
Mohammad Abdullah ◽  
Soo Kum Yoke ◽  
Ahmad Rozaimee Mustaffa

While the discovery of oil contributes a lot towards a country’s economy and technological development, it is also the cause for oil pollution. As such, this study proposes to use lemon peel waste as a low-cost adsorbent to manage oil pollution. For the untreated adsorbent, the lemon peels were cut into small pieces and dried under sunlight for 48 hours. Then, it was further dried in an oven for 24 hours and ground into powder. For the treated adsorbent, the lemon peels were soaked in 0.5 M of sodium hydroxide (NaOH) solution. The adsorbent was used to adsorb different types of oil (diesel oil, lubricant oil, waste vegetable oil) and in different types of water (ocean water, lake water, tap water) with different amounts of adsorbent which is 0.2 g, 0.4 g, 0.6 g, 0.8 g, and 1.0 g for adsorbent dosage experiment. While for types of water experiment, a ratio for volume of water and oil of 3:1, and constant mass adsorbent was used. The result showed that untreated adsorbent can adsorb higher amount of oils than treated adsorbent. The oil that could be easily adsorbed using lemon peels adsorbent is diesel oil with 89.91% adsorption. For the types of water, the result changes according to different types of water and oil used. It was found that the higher the mass adsorbent, the lower the percentage of oil removal. The highest percentage of diesel oil removed in ocean water is 81.68%. While the removal of lubricant oil and waste vegetable oil in lake water is 66.6% and 72.13%, respectively. Scanning Electron Microscopy (SEM) shows that treated lemon peels had small pores compared to untreated lemon peel waste. This study demonstrated and proposed that the lemon peel waste has a good potential in low-cost oil waste removal.


2021 ◽  
Vol 28 ◽  
Author(s):  
Ambreen Shoaib ◽  
Mohammad Tabish ◽  
Shafat Ali ◽  
Azher Arafah ◽  
Muneeb U Rehman ◽  
...  

: Cancer is a multi-factorial health condition involving uncontrolled cell divisions. The disease has its roots in genetic mutation. This disease affects men, women, and even children. Chemotherapy, photodynamic, photothermal, and hormonal therapies have been used to treat this deadliest disease but a huge percentage of patients have chances of disease recurrence or resistance. Nowadays dysregulation in miRNAs is considered one of the key factors for the development and progression of different types of cancers as they control the expression of genes responsible for cell proliferation, growth, differentiation, and apoptosis. Dietary phytochemicals with anticancer properties have been gaining focus for cancer treatment since they are found more effective in targeting cancer via regulating miRNAs expression. These phytochemicals have no side effects and are readily available at a low cost. Several dietary phytochemicals with regulatory effects on the expression of miRNAs have been reported and include curcumin, diallyl disulphide, 3, 30-diindolylmethane, ellagic acid, genistein, indole-3-carbinol, quercetin, resveratrol, and sulforaphane. They exert their regulatory effects against different types of cancer either by upregulating or downregulating different cancer signalling pathways and inhibit its progression. Curcumin down-regulates SHH pathways, epigallocatechin-3-gallate regulates the Notch pathway, inhibits TGFβ1/SMAD signalling, resveratrol regulates the Wnt/β-catenin pathway, and carnosic acid-induced apoptosis in colon cancer cell via JAK2/STAT3 signalling pathway. The miRNAs are used for the treatment of cancer as essential modulators in cellular pathways. Therefore, identifying the miRNAs and their targets and counter them with specific phytochemicals provides a safe and effective mechanism for the treatment of cancer.


Author(s):  
Raquel Pinto ◽  
André Cardoso ◽  
Sara Ribeiro ◽  
Carlos Brandão ◽  
João Gaspar ◽  
...  

Microelectromechanical Systems (MEMS) are a fast growing technology for sensor and actuator miniaturization finding more and more commercial opportunities by having an important role in the field of Internet of Things (IoT). On the same note, Fan-out Wafer Level Packaging (FOWLP), namely WLFO technology of NANIUM, which is based on Infineon/ Intel eWLB technology, is also finding further applications, not only due to its high performance, low cost, high flexibility, but also due to its versatility to allow the integration of different types of components in the same small form-factor package. Despite its great potential it is still off limits to the more sensitive components as micro-mechanical devices and some type of sensors, which are vulnerable to temperature and pressure. In the interest of increasing FOWLP versatility and enabling the integration of MEMS, new methods of assembling and processing are continuously searched for. Dielectrics currently used for redistribution layer construction need to be cured at temperatures above 200°C, making it one of the major boundary for low temperature processing. In addition, in order to accomplish a wide range of dielectric thicknesses in the same package it is often necessary to stack very different types of dielectrics with impact on bill of materials complexity and cost. In this work, done in cooperation with the International Iberian Nanotechnology Laboratory (INL), we describe the implementation of commercially available SU-8 photoresist as a structural material in FOWLP, allowing lower processing temperature and reduced internal package stress, thus enabling the integration of components such as MEMS/MOEMS, magneto-resistive devices and micro-batteries. While SU-8 photoresist was first designed for the microelectronics industry, it is currently highly used in the fabrication of microfluidics as well as microelectromechanical systems (MEMS) and BIO-MEMS due to its high biocompatibility and wide range of available thicknesses in the same product family. Its good thermal and chemical resistance and also mechanical and rheological properties, make it suitable to be used as a structural material, and moreover it cures at 150°C, which is key for the applications targeted. Unprecedentedly, SU-8 photoresist is tested in this work as a structural dielectric for the redistribution layers on 300mm fan-out wafers. Main concerns during the evaluation of the new WLFO dielectric focused on processability quality; adhesion to multi-material substrate and metals (copper, aluminium, gold, ¦); between layers of very different thicknesses; and overall reliability. During preliminary runs, processability on 300 mm fan-out wafers was evaluated by testing different coating and soft bake conditions, exposure settings, post-exposure parameters, up to developing setup. The outputs are not only on process conditions and results but also on WLFO design rules. For the first time, a set of conditions has been defined that allows processing SU-8 on WLFO, with thickness values ranging from 1 um to 150 um. The introduction of SU-8 in WLFO is a breakthrough in this fast-growing advanced packaging technology platform as it opens vast opportunities for sensor integration in WLP technology.


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