scholarly journals Preparation of Hydrothermally Solidified Materials from Waste Cathode Ray Tube Panel Glass for Construction Applications

2021 ◽  
Author(s):  
Qingbo Xu ◽  
Jing Zhang ◽  
Shunyi Li
Keyword(s):  
Glass Powder ◽  
Construction Material ◽  
Steam Pressure ◽  
Processing Method ◽  
Saturated Steam ◽  
Hydrothermal Processing ◽  
High Quality ◽  
Slaked Lime ◽  
Cathode Ray Tube ◽  
Panel Glass

Abstract Solidification of cathode ray tube (CRT) panel glass was carried out using a hydrothermal processing method. In this way, the glass powder was first compacted in a mold at 20 MPa, and then hydrothermally cured in an autoclave under saturated steam pressure at 200 ℃ for 6 hours. The CRT panel glass was then hydrothermally solidified by the formation of tobermorite (Ca5Si6O16(OH)2·4H2O), which was encouraged by the addition of slaked lime (Ca(OH)2). The final solidified specimen’s strength was heavily depended on the amount of tobermorite formed, with higher concentrations of tobermorite producing commensurately greater mechanical strength. With the addition of slaked lime at 20%-30% by mass, the specimen achieved a flexural strength of approximately 16 MPa, which is sufficiently great for using as a construction material. As such, there is cause to believe that the hydrothermal processing method used here may have substantial potential for the product of high-quality recycled CRT panel glass with properties suitable for utilization as a construction material.

Waste cathode-ray-tube glass powder modified asphalt materials: Preparation and characterization

2021 ◽  
pp. 127949
Author(s):  
Dongzhao Jin ◽  
Jiaqing Wang ◽  
Lingyun You ◽  
Dongdong Ge ◽  
Chaochao Liu ◽  
...  
Keyword(s):  
Glass Powder ◽  
Modified Asphalt ◽  
Asphalt Materials ◽  
Cathode Ray Tube ◽  
Materials Preparation

scholarly journals Comparative evaluation of the efficacy of plants for disinfection of medical waste

2019 ◽  
Vol 95 (7) ◽  
pp. 614-617 ◽  
Author(s):  
Alisa V. Balakayeva ◽  
N. V. Rusakov
Keyword(s):  
Comparative Evaluation ◽  
Steam Pressure ◽  
Medical Waste ◽  
Saturated Steam ◽  
Physical Methods ◽  
Microwave Exposure ◽  
Moist Heat ◽  
Chemical Disinfection

There are presented results of the comparative evaluation of the effectiveness of plants for disinfection of medical waste which use 4 most common hardware technologies: treatment by saturated steam pressure, moist heat, microwave exposure and chemical disinfection with refinement. The efficiency ofplants using physical methods of influence was shown to be higher in comparison with hardware chemical disinfection.

scholarly journals Kuat Tekan Beton Mutu Tinggi dengan Memanfaatkan Fly Ash dan Bubuk Kaca Sebagai Bahan Pengisi

2020 ◽  
Vol 20 (01) ◽  
pp. 61-68
Author(s):  
Siska Apriwelni ◽  
Nugraha Bintang Wirawan
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Glass Powder ◽  
Concrete Mixture ◽  
Strength Testing ◽  
Concrete Compressive Strength ◽  
High Quality ◽  
Glass Waste ◽  
Powder Addition ◽  
Compressive Strength Of Concrete

(ID) Penelitian ini membahas pengaruh kuat tekan beton mutu tinggi dengan memanfaatkan limbah fly ash dan limbah kaca. Tujuan dari penelitian ini untuk mengetahui kuat tekan beton pada masing-masing variasi, mengetahui persentase campuran beton untuk menghasilkan kuat tekan maksimum, dan mengetahui apakah fly ash dan serbuk kaca efektif digunakan secara bersamaan sebagai bahan campuran beton. Komposisi fly ash terdiri dari 5 variasi yaitu persentase 0%, 5%, 10%, 15%, dan 20%. Sedangkan untuk komposisi serbuk kaca terdiri dari 2 variasi yaitu persentase 5% dan 10%. Jumlah benda uji 30 buah silinder berukuran diameter 15 cm dan tinggi 30 cm dengan 3 benda uji untuk setiap variasi. Perencanaan campuran beton menggunakan SNI 03-2834-2000 yang dimodifikasi. Pengujian kuat tekan diuji pada umur beton 28 hari. Beton dengan fly ash 0% dan serbuk kaca 10% memiliki kuat tekan paling tinggi dibandingkan dengan beton dengan tambahan fly ash, yaitu 46,77%. Selain itu, dapat disimpulkan bahwa semakin bertambahnya jumlah persentase serbuk kaca yang digunakan menunjukkan bahwa kuat tekan beton semakin bertambah juga. Penambahan fly ash pada campuran beton mempengaruhi kuat tekan beton yang dihasilkan. Pada variasi fly ash 0% memiliki kuat tekan tertinggi baik pada saat campuran serbuk kaca 5%dan 10%. Variasi fly ash 15% adalah kondisi optimum campuran beton dengan kuat tekan beton yaitu 43,31 Mpa. Kedua limbah ini dapat dikombinasikan dan dimanfaatkan dengan baik dan digunakan dalam pembuatan beton mutu tinggi. (EN) This study discusses the effect of high quality concrete by utilizing fly ash and glass waste. The purpose of this study is to determine the compressive strength of concrete in each variation, to determine the contribution of concrete to produce compressive strength, and to find out that fly ash and glass powder are effectively used in full as a concrete admixture. Fly ash composition consists of 5 variations, namely the percentage of 0%, 5%, 10%, 15%, and 20%. While for the composition of glass powder consists of 2 variations, namely the percentage of 5% and 10%. The number of specimens is 30 cylinders with a diameter of 15 cm and a height of 30 cm with 3 specimens for each variation. Concrete mixture planning using SNI 03-2834-2000 was developed. Compressive strength testing on concrete age 28 days. Concrete with 0% fly ash and 10% glass powder have the highest compressive strength compared to concrete with additional fly ash, which is 46.77%. In addition, it can increase the amount of glass powder addition that is used to show the concrete compressive strength is increasing as well. The addition of fly ash in the concrete mixture has an effect on the compressive strength of the concrete produced. In the variation of 0% fly ash has the highest compressive strength when the glass powder mixture of 5% and 10%. The 15% fly ash variation is the optimal concrete mixture with compressive strength of 43.31 MPa. These two wastes can be combined and utilized properly and are used in making high quality concrete.  

scholarly journals Treatment and reuse of coalmine wastewater in Vietnam: application of microfiltration

2018 ◽  
Vol 53 (3) ◽  
pp. 133-142 ◽  
Author(s):  
H. T. T. Dang ◽  
H. D. Tran ◽  
S. H. Tran ◽  
M. Sasakawa ◽  
R. M. Narbaitz
Keyword(s):  
Pilot Scale ◽  
High Quality ◽  
Polyaluminum Chloride ◽  
Slaked Lime ◽  
Scale Test ◽  
Pre Treatment ◽  
Coated Sand ◽  
Quang Ninh ◽  
Wastewater Treatment Systems ◽  
Technical Regulations

Abstract Due to stringent local regulations and adverse environmental impacts, Vietnamese coal mining industries are under pressure to reuse the large volume of wastewater they produce. To this end, the aim of this study was to add microfiltration (MF) membranes after the conventional Vietnamese coalmine wastewater treatment systems (coagulation/sedimentation/filtration) to assess the feasibility of effluent reuse. The pilot-scale test was performed at a coalmine plant located in Quang Ninh province, Vietnam. Results indicate that precipitation with slaked lime (Ca(OH)2) and polyaluminum chloride (PACl) followed by sand filtration are important pre-treatment steps, prior to microfiltration. To achieve high Mn removals the sand in the filter had to be replaced by a KMnO4 coated sand. The MF membrane produced a stable and high quality effluent that meets the Vietnamese National Technical Regulations for Drinking Water quality (Fe < 0.5 mg/L, Mn < 0.3 mg/L, hardness <350 mg/L as CaCO3). Complete membrane recovery was achieved by sequential 24 h soakings in NaOCl, citric acid and a surfactant.

Thermodynamics of James Watt – Ignored or not Understood?

2021 ◽  
Vol 42 (3) ◽  
pp. 397
Author(s):  
Jovan Mitrovic
Keyword(s):  
Latent Heat ◽  
Heat Engine ◽  
Primary Source ◽  
Rankine Cycle ◽  
Theoretical Work ◽  
Steam Pressure ◽  
Steam Engine ◽  
Saturated Steam ◽  
Maximum Efficiency ◽  
Starting Point

In the analysis of the development of thermodynamics as a science, the theoretical work of Sadi Carnot, published in 1824, is generally considered to be the starting point. Carnot studied the cycle of an ideal heat engine and formulated the condition for its maximum efficiency. In this article we examine James Watt’s contributions to the formation of fundamental concepts of thermodynamics, made in the course of his work on improving the Newcomen engine and developing his own steam engine. It is shown that Watt was the first to characterize thermodynamic properties such as latent heat and vapor density. The authors prove Watt’s priority in the studies of the dependence of saturated steam pressure on temperature, in which a critical point was found when the latent heat disappears. These results of Watt anticipated by many decades the studies on the thermodynamic critical state by Th. Andrews and J. Thomson. The article also discusses Wattʼs research on thermodynamic cycles. It is shown that he was the first to study the Rankine cycle with superheated steam, known from the history of thermodynamics. Watt was also the first scientist to introduce the concept of a steam engine’ volumetric work as the product of pressure and volume, and developed a device, the steam pressure indicator, to measure its value. We show the results obtained by Watt with steam to be considerably ahead of Prescott Jouleʼs work on the cooling and condensation of gases during expansion. The article presents an interpretation of Watt’s 1769 patent that is very important as the primary source for a subsequent study and establishment of the principles of energy conversion. The factual material presented in this article suggests that Watt’s scientific research have not been properly understood or simply went unnoticed.

scholarly journals Characterization of the Siderurgy Slags as the Presence of Natural Radionuclides

Proceedings ◽  
2018 ◽  
Vol 2 (20) ◽  
pp. 1296
Author(s):  
Diogo T. Moreira ◽  
Arno H. Oliveira ◽  
Adriana S. M. Batista
Keyword(s):  
Construction Material ◽  
Natural Radionuclides ◽  
Steel Slag ◽  
Building Industry ◽  
High Quality ◽  
Mineral Aggregate ◽  
Steelmaking Slags ◽  
Preliminary Study ◽  
Metallurgical Processes

Present day steelmaking slags are being successfully used as a high quality mineral aggregate for the building industry. With this, it is of vital importance to be familiar with the technical significance of the secondary application of steel slag, because some steel slag might contain increased concentration of substances harmful to human health. In terms of steel slag impact on the environment, radionuclides are the least researched of all pollutants emitted from the metallurgical processes. This work presents the preliminary study about the presence of the uranium in siderurgy slag aggregates for the purpose of its use in the production of construction material. The results showed that this slag is free of uranium which brings greater security in its use as building material.

scholarly journals Impact of Instant Controlled Pressure Drop (DIC) Treatment on Drying Kinetics and Caffeine Extraction from Green Coffee Beans

2012 ◽  
Vol 1 (1) ◽  
pp. 24 ◽  
Author(s):  
I. Kamal ◽  
A. Gelicus ◽  
K. Allaf
Keyword(s):  
Pressure Drop ◽  
Initial Moisture Content ◽  
Effective Diffusivity ◽  
Steam Pressure ◽  
Raw Material ◽  
Saturated Steam ◽  
Drying Time ◽  
Hot Air ◽  
Instant Controlled Pressure Drop ◽  
The Impact

<p>The present work is directed towards the impacts of Détente InstantanéeContrôléeDIC (French, for instant controlled pressure-drop) in terms of decaffeination and drying of Ethiopian green coffee beans (GCBs).DICconsisted in subjecting the product to a high-pressure saturated steam during some seconds and ended with an abrupt pressure drop towards a vacuum. A conventional aqueous extraction and a hot air-drying took place after DIC treatment. Inthis study, Response Surface Method (RSM) was used withDIC saturated steam pressure P, thermal treatment time t, and initial moisture content W asthe independent variables. Both direct DICextract recovered from the vacuum tank and the aqueous extracts wereanalyzed and quantified using the reversed phase-HPLC. With decaffeination ratiosas dependent variables, P and Wwere the most significant operating parameters; whilet was much weaker.Total decaffeination ratio could reach 99.5% after DIC treatment at specificconditions of W=11.00% db, P=0.1 MPa, and t=35swhile it was only 58% when achieved with untreated raw material.</p> The effective diffusivity  and the starting accessibility  were calculated from the diffusion/surface interaction kinetic model of hotair drying after DIC treatment. They dramatically increased with P and t while W had a weak impact.Thus, at the optimized DICconditions, and  increased from 0.33 to 12.60 10<sup>-10</sup>m² s<sup>-1</sup>and from 0.75 to 11.53 g/100 g db, respectively. Drying time needed to reach 5% db became 60 min instead of 528 min for untreated raw material. <p>RSM analysis showed that the DIC saturated steam pressure P and the initial moisture content W were the most significant variables both affecting the decaffeination ratio; the impact of the total thermal processing time t was much weaker. Total decaffeination ratio could reach 99.5% after DIC treatment at specific conditions of W=11.00% db, P=0.1 MPa, and t=35 s while it was only 58% when achieved with untreated raw material.</p> <p>Using diffusion/surface interaction model of hot-air drying kinetics just after DIC treatment, we could observe that DIC expansion dramatically improved the drying kinetic parameters, with P and t as the most significant DIC operating parameters while the impact of W was much weaker. Thus, the optimized DIC treatment allowed the effective diffusivity  and the starting accessibility to increase from 0.33 10<sup>-10</sup> m² s<sup>-1</sup> and 0.75 g/100 g db to 12.60 10<sup>-10</sup> m² s<sup>-1</sup> and 11.53 g/100 g db, respectively. Drying time needed to reach 5% db became 60 min instead of 528 min for untreated raw material.</p>

scholarly journals Perilaku Keruntuhan Balok Beton Mutu Normal Dengan Pengekangan Pada Daerah Tekan

2020 ◽  
Vol 8 (2) ◽  
pp. 125-131
Author(s):  
Tahan Tahan
Keyword(s):  
Concrete Beams ◽  
Construction Material ◽  
High Quality ◽  
Element Analysis ◽  
Steel Material ◽  
Pressure Area ◽  
Respective Field ◽  
Collapse Behavior ◽  
Economic Price

Concrete is a widely used construction material now Compared to other materials such as wood and steel. This is because the constituent material is easy to obtain, has enough strength, good durability, the making process is easy and in terms of economic price affordable. Concrete is Generally classified into two classes, namely normal quality and high quality. Both of them are now widely used in the construction activities. Normal quality concrete has a quality of 20 Mpa up to 58 MPa, while high quality concrete ranges above 58 Mpa. One of the applications in the structures is collapse behavior concrete beams on the normal quality of norm with the confinement on the pressure area. To analyze the effect of collapse behavior of normal quality concrete beams and varied Finite Element Analysis (FEA) by using ANSYS Ed. 9.0 with stirrups variation space in te respective spans (40, 80,120,150) mm and stirrup variation distance in the respective field (40,80,120,125,150,100,75.50) mm with 15/20 beam size. The steel material used has stress power of 400 each Mpa, stirrup stress 200 Mpa, normal quality stress 25 Mpa. Based on manual analysis and FEA the magnitude of ultimate capacity that occurs in the model of the beam with the dense stirrup on the stress area the ultimate moment value will rise both in the moment span area and in the field. The deformation is decreasing and the crack behavior on the pressure area can be minimized

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