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Online since: September 2013
Authors: Meena Wadhwani, Shubha Jain
Materials and Methods  The chemicals used were of analar grade and doubly distilled water was used throughout to prepare the solutions.
Analysis of Reaction Products Substrate (9g/100ml), CAT (0.563 gm/100ml) and water were mixed in a flask and the flask was kept under tungsten lamp.
The evolution of CO2 has been confirmed by lime water test.
· The photochemical oxidation of glucose by chloramine-T in acidic medium gives formic acid, formaldehyde, CO2, water and HCl as the reaction products.
[6].Mathlouthi M. & Reiser P., Blackie Academic & Professional, London, (1994) 116
Online since: January 2019
Authors: Peng Yu Yan, Z.K. Zheng, Wei Min Mao
Then, the temperature of the alloy liquid cooled to the given pouring temperature, and the alloy liquid was poured into the water-cooled serpentine channel.
After that, the collective mold with slurry was rapidly placed in a water pool within 2~3 seconds to retain the slurry microstructure at high temperature as far as possible.
The water-cooled copper serpentine pouring channel had three curves along the inner channel.
The area A and the perimeter P of every primary silicon grain on a photo were automatically measured by a professional image analysis software.
When A390 alloy liquid is poured into the water-cooled copper serpentine pouring channel, the superheated liquid will flow down along the inner wall of the channel.
Online since: February 2019
Authors: Koh Heng Boon, RASHEED ALTOUHAMI, Hassan Ali, Ashraf Radwan, Ng Wei Shen, Mundr Mansur
When mixing mortar with new and innovation material, property specification which classifies mortar by performance (compressive strength, water retention, and air content) is preferable [8].
The cement-to-fine aggregate ratio was 1:3 (by weight), and cement for construction professionals CEM II/B-L 32.5 R was used.
Sandy clay was dried naturally under the sunlight for one to two days to ensure there is no any effect on water- cement ratio during mix design.
According to BS [18], the mixing proportion of the cement and fine sand for mortar is 1:3, while water content was determined based on workability test.
All specimens were cured under the water until the testing age, which is 7, 14 and 28 days.
Online since: July 2024
Authors: Pablo Jhoel Peña Torres, Alvaro Fabrizio Aliaga Guevara, Andre Jhoel Lamas Chavez
The research aims to provide valuable insights for engineers, architects, and construction professionals interested in sustainable materials, offering a comprehensive understanding of the challenges and advantages associated with recycled concrete in high-temperature environments.
This strategy not only reduces the demand for natural resources, such as gravel and sand extraction, but also minimizes the amount of construction and demolition waste that ends up in landfills, thus contributing to the reduction of soil and water pollution [16].
When the aggregates are extracted from the quarries, environmental problems are caused, such as geological erosion, water and air pollution, vibration, noise and modification of the landscape or environment.
The plasticizing admixture was used to reduce the amount of water in the mix.
This method consists of subjecting the recycled aggregate to hydrochloric acid for 24 hours to then separate the adhered mortar by washing with water.
Online since: July 2015
Authors: Al Khalid Othman, Hushairi Zen, Mohd Azlan Ismail
The favourable characteristics of PAT are indeed important as they reduce the dependence on third-party professional services which can be very expensive.
Water with density of 1000 kg/m3 at 25°C was chosen as the working fluid in this study.
As water enters into the impeller, the pressure decreases along the impeller channel due to conversion of energy from fluid energy to rotational mechanical energy.
The velocity vector of the water entering the pump inlet reveals no sudden change in flow patterns, with a smooth velocity transition.
The water is directed by the curvature of the volute wall (which has a spiral shape) and thus maintains an even flow path to the impeller.
Online since: June 2014
Authors: Claudinei Rezende Calado, F.A.R. Calado, G. Caput, S.C. Gomes, R.M. Andrade
The image processing algorithms were developed using the Matlab 2010a platform and tested on a PC-type computer with a 2.2 GHz processor, 1 GB of RAM and Windows XP Professional OS; the tests were performed in triplicate.
Table 1: Linear retraction, apparent density, apparent porosity and water absorption data.
Sample Linear retraction (%) Apparent density (g cm-3) Apparent porosity (%) Water absorption (%) Diameter ± Des.
For the 4th sample, the apparent density decreased as the apparent porosity and water absorption increased.
The remaining samples had water absorption values above 3.0%.
Online since: February 2014
Authors: Pavlo V. Kryvenko, Lu Qian Weng, Hai Lin Cao, V.I. Pushkar, O.N. Petropavlovsky, A.Yu. Kovalchuk, Yue Guo
Table 1 Chemical composition Basic oxides Quantity of oxide, % Slag Fly ash Portland cement SiO2 39.4 51.61 25.4 SO3 1.4 0.17 2.37 MgO 5.19 0.82 2.51 Al2O3 6.8 32.31 5.28 MnO 0.32 - 0.17 CaO 47.38 5.19 60.31 Fe2O3 - 6.63 2.9 FeO 0.32 - K2O 0.52 1.36 0.49 Na2O 0.6 0.28 TiO2 0.26 - 0.28 Table 2 Concrete mix compositions No 1 No 2 No 3 Slag 352 317 352 ОРС 8 8 8 Fly ash - 70 - Sand 670 670 670 Crushed stone 1150 1115 1150 Water 148.3 152 160 Na2CO3 16 16 8 Na2SiO35Н2О 24 24 32 Density, kg/m3 2390 2400 2400 A cast-in-situ concrete wall (width= 3 m, height= 7 m and length over 100 m) was taken as an object for modeling.
A numerical modeling of a thermostressed state was performed using the professional software product “Elcut” [3].
Crack tip critical –stress- intensity factor vs. crack depth (mm) Despite the fact that alkali activated cement concretes are characteristic of shrinkage deformations at levels of Portland cement concretes [5], however, their lower temperature in the conditions of hot climate causes the less diffusion of water vapors into the ambient environment and, hence, acceleration of shrinkage processes in the concrete.
So, in case of the alkali activated slag cement concretes when a difference between the temperature of the concrete and of the ambient environment of 20оС, the rate of water diffusion into the ambient environment, in accordance with the Fick’s Law can show a 12- fold increase.
At the same time, in case of Portland cement concrete, when a difference between the concrete temperature and the temperature of ambient environment is 40оС, the rate of water diffusion can show more than 38- fold increase.
Online since: October 2011
Authors: Ren Guo Gu, Wei Dong Pan, Gui Xian Hu, Xiao Long Sheng
Table.1 Summary table of Monitoring Items and Frequency Number Monitoring Item Monitoring Frequency From the beginning of foundation excavation to 3-day after the completion of concrete pouring of the structure foundation slab Form 3-day-after completion of structure slab concrete pouring to beginning of underground structure construction, and to roof elevation From building support removing to 3-day after Support removing complete Common situation 1 Lateral deformation monitoring 1 time/day 1 time/day 2~3 times/week 2 Horizontal displacement monitoring 1 time/day 1 time/day 2~3 times/week 3 Settlement monitoring 1 time/day 1 time/day 2~3 times/week 4 Water level monitoring 1 time/day 1 time/day 2~3 times/week 5 Building Cracks monitoring 1 time/week 1 time/week 1 time/week 6 Stress of Building envelope structure monitoring 1 time/day 1 time/day 2~3 times/week 7 Earth pressure monitoring 1 time/2-day 1 time/2-day 2~3 times/week 8 Pore water pressure monitoring 1 time/2-day 1 time/2-day
A robust project monitoring organization must establish an administration panel which comprised by project leader, technical director and experienced professional monitoring staffs.
Beijing: China Water Power Press, 2008 [3] Wu Zhenjun, Wang Hao, Wang Shuilin, et al.
Study on Management and Quality Control of Water Automatic Monitoring Early-warning System in Taihu Basin [J].
Online since: March 2022
Authors: Takron Chantadee, Napaphol Puyathorn, Wai Wai Lwin
Drug Center Co., Bangkok, Thailand) was used as surfactant for water phase.
The water phase was prepared by adding the water soluble ingredients and heated in the water bath to 75ºC.
The water phase was added into oil phase and mixed using a homogenizer for 5 min at 6000 rpm.
pH value and rheological behavior determination. pH value of creams was measured using a pH meter (Professional Meter PP-15 Sartorius, Goettingen, Germany).
Tao, An experimental study of stability of oil-water emulsion, Fuel Process.
Online since: February 2019
Authors: Voldemar Muktepavel, Victor Murzin, Vyacheslav M. Karpov, Artur I. Kurakin
Experiments have been performed to determine the value of the arc breaking length of electrodes when welding under water.
Paraffin is applied for the purpose of electric and water proof reasons.
The process of bead forming under the water.
Welding arc is ignited under water and burns to a natural breakup.
The welding operator should be a high-quality professional. 3 The best elasticity of the welding arc for underwater "wet" welding is recorded for EPS-AN1 electrodes; UW-EZ-2 electrodes by BrocoUnderwater have good elasticity, and LKI-1P have the worst one (because of the high content of fluorides).
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