scholarly journals The increased use value of bamboo leaves as silica source for t-type zeolite synthesis

2018 ◽  
Vol 197 ◽  
pp. 05003 ◽  
Author(s):  
Soni Setiadji ◽  
Citra Deliana Dewi Sundari ◽  
Endang Lala ◽  
Denia Febby Nurbaeti ◽  
Ira Novianti ◽  
...  

T-type zeolite can be used as catalyst, adsorbent, and membranes for gas separation. The synthesis of T-type zeolite needs to be optimized in both of the method and source of precursor, because of its relatively high price. In this research, the synthesis is done using silica extracted from bamboo leaves instead of commercial silica. This increases the value of the bamboo leaves and the cost-performance of zeolite synthesis. The silica was extracted from bamboo leaves ash using alkaline solvent. The extracted silica has 81.76% of purity and an amorphous phase. The T-type zeolite was synthesized using the molar composition of 0.15 Na2O : 0.025 Al : 0.15 K2O : 1 SiO2 : 15 H2O : 0.06 TMAOH, under hydrothermal method and heating process for 4 days, 60°C for 2 days and 120°C for the next 2 days. The characterization method using X-Ray Diffraction and Infra-Red Spectroscopy were performed to confirm the formation of T-type zeolite. The results of Scanning Electron Microscope (SEM) analysis show that the formed T-type zeolite has erionite cylindrical crystal shape.

2015 ◽  
Vol 1112 ◽  
pp. 528-532 ◽  
Author(s):  
Muhammad Olvianas ◽  
Mazaya Najmina ◽  
Bernardo Saktya Ludy Prihardana ◽  
Fransiskus A.K.G.P. Sutapa ◽  
Anis Nurhayati ◽  
...  

Geothermal plant produces numerous kinds of possible side products. One of them is silica as a consequence of the existing silica scaling problem which causes geothermal power plant efficiency depletion. The silica recovery possesses a way to utilize it. Geopolymer concrete is a solution to utilize the abundance recovered geothermal silica with low energy consumption and green house gas emission. Thus, in this study, the geopolymerization of geothermal silica and kaolinite will be observed. Geopolymer was inorganic polymer consist of Si and Al atoms that formed through polymerization process. The raw materials being used are geothermal silica as amorphous silica source and kaolinite as alumina source, whereas the activator composed of sodium hydroxide and sodium silicate. Geothermal silica possesses amorphous structure which had been proven by X-Ray Diffraction (XRD) and X-Ray Fluorescence (XRF) analysis with 96.09% silica (SiO2) content and 18.92% alumina (Al2O3) content of kaolinite. The experiment conducted to determine geopolymerization rate of geothermal silica and kaolinite reaction in presence of alkali activator with certain composition and temperature variation ranged from 80°C up to 120°C. Study on geopolymerization rate was carried out by observing geopolymer bond along with the compressive strength as a function of curing time and temperature. As for geopolymer bonds for each sample with different curing temperatures, FTIR and SEM analysis were used to investigate.


Author(s):  
Сергей Борисович Казаков ◽  
Дмитрий Михайлович Шишов ◽  
Антон Игоревич Ларин ◽  
Александр Петрович Николаев ◽  
Аза Валерьевна Писарева

В статье представлен обзор существующих технических решений в сфере мониторинга и предотвращения апноэ во сне. Произведён анализ существующих аппаратов для предотвращения апноэ, который показал, что на рынке присутствует большое количество импортных моделей, однако они имеют довольно высокую цену. Разработанный нами Российский аналог проектируемого аппарата, при схожих характеристиках, будет иметь более привлекательную цену, чем у импортных приборов. Интегрирование датчика влажности в персональную маску пациента даёт возможность отслеживать остановки дыхания пациента во время сна, и тем самым включать процесс принудительной подачи дыхательной смеси именно в тот момент, когда она необходима для устранения патологии. Целью научной работы является разработка конструкции прибора и создание алгоритма программы для управления аппарата искусственной вентиляции лёгких для предотвращения апноэ во сне. Показана разработка структуры устройства аппарата. Подобран компрессор и датчик влажности с обоснованными характеристиками для создания аппарата, а также основные элементы. Разработана конструкция корпуса аппарата и разработана компоновка. Выполнено технико-экономическое обоснование разработки аппаратно-программного комплекса для предотвращения апноэ во сне. Показано, что себестоимость готового изделия достаточно конкурентна The article presents an overview of existing technical solutions in the field of monitoring and prevention of sleep apnea. An analysis of existing devices for preventing apnea was made, which showed that there are a large number of imported models on the market, but they have a fairly high price. The Russian analog of the designed device developed by us, with similar characteristics, will have a more attractive price than that of imported devices. The integration of the humidity sensor into the patient's personal mask makes it possible to monitor the patient's breathing stops during sleep, and thus enable the process of forced delivery of the respiratory mixture at the exact moment when it is necessary to eliminate the pathology. The purpose of the research is to develop the device design and create a program algorithm for controlling the artificial lung ventilation device to prevent sleep apnea. The development of the device structure is shown. The compressor and humidity sensor with reasonable characteristics for creating the device, as well as the main elements are selected. The design of the device body and its layout were developed. A feasibility study for the development of a hardware and software system for preventing sleep apnea has been completed. It is shown that the cost of the finished product is quite competitive


2020 ◽  
pp. 089270572096564
Author(s):  
Xiao Wang ◽  
Hui Lu ◽  
Jun Chen

In this work, ultra-high molecular weight polyethylene (UHMWPE)/natural flake graphite (NG) polymer composites with the extraordinary high thermal conductivity were prepared by a facile mixed-heating powder method. Morphology observation and X-ray diffraction (XRD) tests revealed that the NG flakes could be more tightly coated on the surface of UHMWPE granules by mixed-heating process and align horizontally (perpendicular to the hot compression direction of composites). Laser flash thermal analyzer (LFA) demonstrated that the thermal conductivity (TC) of composites with 21.6 vol% of NG reached 19.87 W/(m·K) and 10.67 W/(m·K) in the in-plane and through-plane direction, respectively. Application experiment further demonstrated that UHMWPE/NG composites had strong capability to dissipate the heat as heat spreader. The obtained results provided a valuable basis for fabricating high thermal conductive composites which can act as advanced thermal management materials.


Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 1195
Author(s):  
Ali Saberi Derakhtenjani ◽  
Andreas K. Athienitis

This paper presents control strategies to activate energy flexibility for zones with radiant heating systems in response to changes in electricity prices. The focus is on zones with radiant floor heating systems for which the hydronic pipes are located deep in the concrete and, therefore, there is a significant thermal lag. A perimeter zone test-room equipped with a hydronic radiant floor system in an environmental chamber is used as a case study. A low order thermal network model for the perimeter zone, validated with experimental measurements, is utilized to study various control strategies in response to changes in the electrical grid price signal, including short term (nearly reactive) changes of the order of 10–15 min notice. An index is utilized to quantify the building energy flexibility with the focus on peak demand reduction for specific periods of time when the electricity prices are higher than usual. It is shown that the developed control strategies can aid greatly in enhancing the zone energy flexibility and minimizing the cost of electricity and up to 100% reduction in peak power demand and energy consumption is attained during the high-price and peak-demand periods, while maintaining acceptable comfort conditions.


2010 ◽  
Vol 7 (4) ◽  
pp. 1200-1205 ◽  
Author(s):  
Parag Solanki ◽  
Vikal Gupta ◽  
Ruchi Kulshrestha

Coal fly ash was used to synthesize X-type zeolite by alkali fusion followed by hydrothermal treatment. Characteristics of the various Fly ash samples were carried out. Coal proximate analysis was done. Batch experiment was carried out for the adsorption of some heavy metal ions on to synthesized Zeolite. The cost of synthesized zeolite was estimated to be almost one-fifth of that of commercial 13X zeolite available in the market.


Coatings ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 734
Author(s):  
Pablo Fernández-Lucio ◽  
Octavio Pereira Neto ◽  
Gaizka Gómez-Escudero ◽  
Francisco Javier Amigo Fuertes ◽  
Asier Fernández Valdivielso ◽  
...  

Productivity in the manufacture of aircrafts components, especially engine components, must increase along with more sustainable conditions. Regarding machining, a solution is proposed to increase the cutting speed, but engines are made with very difficult-to-cut alloys. In this work, a comparison between two cutting tool materials, namely (a) cemented carbide and (b) SiAlON ceramics, for milling rough operations in Inconel® 718 in aged condition was carried out. Furthermore, both the influence of coatings in cemented carbide milling tools and the cutting speed in the ceramic tools were analysed. All tools were tested until the end of their useful life. The cost performance ratio was used to compare the productivity of the tested tools. Despite the results showing higher durability of the coated carbide tool, the ceramic tools presented a better behavior in terms of productivity at higher speed. Therefore, ceramic tools should be used for higher productivity demands, while coated carbide tools for low speed-high volume material removal.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Maryama Hammi ◽  
Younes Ziat ◽  
Zakaryaa Zarhri ◽  
Charaf Laghlimi ◽  
Abdelaziz Moutcine

AbstractThe main purpose of this study is to elaborate anticorrosive coatings for the welded steel 316L, since this later is widely used in industrial field. Hence, within this work we have studied the electrochemical behaviour of different zones of the welded steel 316 in 1 M HCl media. The macrography study of the welded steel has revealed the different areas with a good contrast. We have stated three different zones, namely; melted zone (MZ), heat affected zone (HAZ) and base metal zone (BM). Impedance studies on welded steel 316L were conducted in 1 M HCl solution, coating of Epoxy/Alumina composite was applied on different zones, in order to reveal the anti-corrosion efficiency in each zone. Scanning electron microscopy (SEM) analysis was undertaken in order to check how far the used coating in such aggressive media protects the studied zones and these findings were assessed by water contact angle measurements. The choice of this coating is based on the cost and the safety. We concluded that the Epoxy/Alumina composite has a good protecting effect regarding welded steel in aggressive media.


2020 ◽  
Vol 10 (11) ◽  
pp. 4032
Author(s):  
Anna-Marie Lauermannová ◽  
Michal Lojka ◽  
Filip Antončík ◽  
David Sedmidubský ◽  
Milena Pavlíková ◽  
...  

The search for environmentally sustainable building materials is currently experiencing significant expansion. It is increasingly important to find new materials or reintroduce those that have been set aside to find a good replacement for Portland cement, which is widely used despite being environmentally insufficient and energy-intensive. Magnesium oxybromides, analogues to well-known magnesium oxychloride cements, fit both categories of new and reintroduced materials. In this contribution, two magnesium oxybromide phases were prepared and thoroughly analyzed. The stoichiometries of the prepared phases were 5Mg(OH)2∙MgBr2∙8H2O and 3Mg(OH)2∙MgBr2∙8H2O. The phase analysis was determined using X-ray diffraction. The morphology was analyzed with scanning and transmission electron microscopy. The chemical composition was studied using X-ray fluorescence and energy dispersive spectroscopy. Fourier transform infrared spectroscopy was also used. The thermal stability and the mechanism of the release of gasses linked to the heating process, such as water and hydrobromic acid evaporation, were analyzed using simultaneous thermal analysis combined with mass spectroscopy. The obtained results were compared with the data available for magnesium oxychlorides.


2016 ◽  
Vol 850 ◽  
pp. 191-196 ◽  
Author(s):  
Wei Wang ◽  
Cun Lei Zou ◽  
Ren Geng Li ◽  
Wen Wen ◽  
Hui Jun Kang ◽  
...  

In situ synchrotron X-ray diffraction was used to study a deformed Cu-0.88 Fe-0.24 P alloy during heating process. The measurements were performed at room temperature and also at high temperatures up to 893 K in order to determine the recovery, ageing and recrystallization process. With the increase of temperature, the angles of copper matrix peaks moved left and the FWHM (full width at half maximum) decreased slightly. Fe3P precipitates were first detected at 533 K, reached the maximum at 673 K, and re-dissolved into matrix at 853 K. A dramatic decrease in FWHM was observed accompanied by the precipitation of Fe3P phases, indicating the reduction of lattice distortion of copper matrix.


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