scholarly journals pH Measurement of Cement-Based Materials: The Effect of Particle Size

2021 ◽  
Vol 11 (17) ◽  
pp. 8000
Author(s):  
Poh Yee Loh ◽  
Payam Shafigh ◽  
Herda Yati Binti Katman ◽  
Zainah Ibrahim ◽  
Sumra Yousuf
Keyword(s):  
Fine Particles ◽  
Ph Value ◽  
Ph Measurement ◽  
Solvent Ratio ◽  
Particle Sizes ◽  
Protective Film ◽  
Special Equipment ◽  
Cement Based Materials ◽  
Forensic Engineering ◽  
Effect Of Particle Size

Healthy reinforced concrete should be highly alkaline to safeguard the passive protective film for reinforcement of steel bars against corrosion. pH measurement is gaining importance in research of cement-based materials (CBMs), such as paste, mortar and concrete, as well as in structural health monitoring and forensic engineering applications. However, insufficient information is available regarding the most practical, economical and applicable quantitative pH measurement method for CBMs from the sampling to measurement stage. Existing recommended methods for measuring pH have many variables that need to be investigated to determine how they influence the pH value. Samples were recommended to be ground into very fine particles for pH measurement. Preparing very fine particles of CBMs is costly and time consuming, while larger particles, with sizes similar to sand particles, are easier to obtain, without needing special equipment. This study aims to investigate the effect of different particle sizes on the pH of cement mortar. Mortar specimens were crushed and sieved to obtain different ranges of particle sizes to measure the pH values. Results showed that specimens with large particle sizes (between 600 µm and 4.75 mm) can produce similar results to specimens with very fine particle sizes (<600 µm) by increasing the solid-to-solvent ratio or the leaching time.

scholarly journals Experimental Analysis of the Mechanical Properties and Resistivity of Tectonic Coal Samples with Different Particle Sizes

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2303
Author(s):  
Congyu Zhong ◽  
Liwen Cao ◽  
Jishi Geng ◽  
Zhihao Jiang ◽  
Shuai Zhang
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
Compressive Strength ◽  
Elastic Modulus ◽  
Uniaxial Compressive Strength ◽  
Coalbed Methane ◽  
Coal Sample ◽  
Fine Particles ◽  
Particle Sizes ◽  
Tectonic Coal

Because of its weak cementation and abundant pores and cracks, it is difficult to obtain suitable samples of tectonic coal to test its mechanical properties. Therefore, the research and development of coalbed methane drilling and mining technology are restricted. In this study, tectonic coal samples are remodeled with different particle sizes to test the mechanical parameters and loading resistivity. The research results show that the particle size and gradation of tectonic coal significantly impact its uniaxial compressive strength and elastic modulus and affect changes in resistivity. As the converted particle size increases, the uniaxial compressive strength and elastic modulus decrease first and then tend to remain unchanged. The strength of the single-particle gradation coal sample decreases from 0.867 to 0.433 MPa and the elastic modulus decreases from 59.28 to 41.63 MPa with increasing particle size. The change in resistivity of the coal sample increases with increasing particle size, and the degree of resistivity variation decreases during the coal sample failure stage. In composite-particle gradation, the proportion of fine particles in the tectonic coal sample increases from 33% to 80%. Its strength and elastic modulus increase from 0.996 to 1.31 MPa and 83.96 to 125.4 MPa, respectively, and the resistivity change degree decreases. The proportion of medium particles or coarse particles increases, and the sample strength, elastic modulus, and resistivity changes all decrease.

scholarly journals Regression Analysis of Orthogonal, Cylindrical and Multivariable Color Parameters for Colorimetric Surface pH Measurement of Materials

Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3682
Author(s):  
Katarína Vizárová ◽  
Izabela Vajová ◽  
Naďa Krivoňáková ◽  
Radko Tiňo ◽  
Zdenko Takáč ◽  
...  
Keyword(s):  
Ph Value ◽  
Critical Factor ◽  
Ph Measurement ◽  
Ph Indicator ◽  
Water Quality Control ◽  
Quality Management Systems ◽  
Surface Ph ◽  
Regression Parameters ◽  
Ph Detection

The surface pH is a critical factor in the quality and longevity of materials and products. Traditional fast colorimetric pH detection-based tests such as water quality control or pregnancy tests, when results are determined by the naked eye, cannot provide quantitative values. Using standard pH papers, paper-printed comparison charts, or colorimetric microfluidic paper-based analytical devices is not suitable for such technological applications and quality management systems (QMSs) where the particular tested material should contain a suitable indicator in situ, in its structure, either before or after the process, the technology or the apparatus that are being tested. This paper describes a method based on the combination of impregnation of a tested material with a pH indicator in situ, its exposure to a process of technology whose impact on pH value is to be tested, colorimetric pH measurement, and approximation of pH value using derived pH characteristic parameters (pH-CPs) based on CIE orthogonal and cylindrical color variables. The hypotheses were experimentally verified using the methyl red pH indicator, impregnating the acid lignin-containing paper, and preparing a calibration sample set with pH in the range 4 to 12 using controlled alkalization. Based on the performed measurements and statistical evaluation, it can be concluded that the best pH-CPs with the highest regression parameters for pH are √∆E, ln (a),√∆H (ab), a/L, h/b and ln (b/a). The experimental results show that the presented method allows a good estimation of pH detection of the material surfaces.

Effect of Particle Size on the Oil Yield and Catechin Compound Using Accelerated Solvent Extraction

2013 ◽  
Vol 60 (1) ◽  
Author(s):  
Mohd Azizi Che Yunus ◽  
Manzurudin Hasan ◽  
Norasikin Othman ◽  
Siti Hamidah Mohd-Setapar ◽  
Liza Md.-Salleh ◽  
...  
Keyword(s):  
Particle Size ◽  
Solvent Extraction ◽  
Accelerated Solvent Extraction ◽  
Extraction Time ◽  
Oil Yield ◽  
Particle Sizes ◽  
Experimental Range ◽  
Areca Catechu ◽  
Effect Of Particle Size ◽  
Extraction Cycle

Kajian ini bertujuan untuk mengkaji kesan saiz zarah ke atas pengekstrakan sebatian catechin daripada biji Areca catechu L. dengan menggunakan Pengekstrakan Pelarut Terpecut (PPT). Saiz zarah biji Areca catechu dipelbagaikan dari 75 μm sehingga 500 μm. Pengekstrakan telah dijalankan padaparameter tetap iaitu suhu (140oC), tekanan (1500 psi), masa (10 minit), isipadu semburan (60%) dan satu kitaran pengekstrakan, masing-masing. Hasil minyak peratusan yang lebih tinggi adalah 300 mg minyak / gram sampel (30.00% pati minyak) ditemui pada 125 μm. Walaubagaimanapun, kandungan catechin dalam pati minyak hanya 0.0375 mg catechin / gram sampel. Saiz zarah yang terbaik dalam julat uji kaji ini telah dikenal pasti pada 500 μm yang memberikan kandungan catechin yang tinggi iaitu 0.0515 mg catechin / gram sampel dari 247.5 mg minyak / gram sampel (24.75% pati minyak). Kata kunci: Saiz zarah; catechin; LC-MS-TOF; pengekstrakan pelarut terpecut The purpose of this work is to investigate the effects of particle size on the extraction of catechincompound from Areca catechu L. seeds by using Accelerated Solvent Extraction (ASE). The particle sizes of Areca catechu L. seeds are varied from 75 µm until 500 µm. The extraction is conducted at fixed parameters which are temperature (140oC), pressure (1500 psi), extraction time (10 minutes), flush volume (60%) and the static cycle is done for 1 extraction cycle respectively. Higher percentage oil yield of 300mg oil/gram of sample (30.00% oil yield) is found at 125 µm. However, the amount of catechin in oil yields is only 0.0375 mg of catechin/gram of sample. The best of particle size within the experimental range has been identified at 500 µm which gives a high content of catechin with 0.0515 mg Catechin/gram of sample from 247.5 mg oil/gram of sample (24.75% oil yield). Keywords: Particle size; catechin; LC-MS-TOF; accelerated solvent extraction

Effect of Particle Size of ZrO2(Y2O3) Powders on the Shrinkage of the Sintered Substrate with Coloring Gradient

2014 ◽  
Vol 87 ◽  
pp. 162-168
Author(s):  
Paula Cipriano da Silva ◽  
Roberto de Oliveira Magnago ◽  
Camila Aparecida Araujo da Silva ◽  
Bianca de Almeida Fortes ◽  
Claudinei dos Santos
Keyword(s):  
White Layer ◽  
Linear Shrinkage ◽  
Particle Sizes ◽  
X Ray Diffraction ◽  
X Ray ◽  
Particles Size Distribution ◽  
Cad Cam ◽  
Effect Of Particle Size ◽  
Cam Systems ◽  
Zirconia Powders

ZrO2(Y2O3)-based ceramics with coloring gradient can facilitate the development of dental prosthesis by the improvement of esthetic properties. In this work, ZrO2 powders with different particle sizes were investigated. White and yellow zirconia powders (TOSOH Corporation-Japan) were characterized by particles size distribution using nanoSight-LM20 analyzer. Furthermore, samples were characterized by X-Ray diffraction, Scanning Electron Microscopy and relative density. Compacts with two layers, one white and one yellow were uniaxially pressed at 80MPa and sintered at 1530°C-120min. The yellow-powder presented average particles size of 180±66nm, while the white-powder presented particles size of 198±73nm. After sintering, full dense ceramics with tetragonal phase were obtained. The linear shrinkage of the yellow and white-layer was 22.75% and 22.05% respectively. This difference in shrinkage is important in the machining of prostheses in ceramic CAD/CAM systems, because they lead to difficulties in adapting this customized prosthesis in patients.

The use of hollow sphere pigments as strength additives in paper and paperboard coatings—Part 1: The predictive nature of packing models on coating properties

TAPPI Journal ◽  
2020 ◽  
Vol 19 (11) ◽  
pp. 585-593
Author(s):  
ETHAN GLOR ◽  
BRIAN EINSLA ◽  
JOHN ROPER ◽  
JIAN YANG ◽  
VALERIY GINZBURG
Keyword(s):  
Particle Size ◽  
Hollow Sphere ◽  
Particle Packing ◽  
Particle Sizes ◽  
Coating Properties ◽  
Ideal System ◽  
Thermal Paper ◽  
Effect Of Particle Size ◽  
Low Levels ◽  
Better Than

Hollow sphere pigments (HSPs) are widely used at low levels in coated paper to increase coating bulk and to provide gloss to the final sheet. However, HSPs also provide an ideal system through which one can examine the effect of pigment size and particle packing within a coating due to their unimodal and tunable particle sizes. The work presented in Part 1 and Part 2 of this study will discuss the use of blends of traditional inorganic pigments and HSPs in coating formulations across a variety of applications for improved coating strength. Part 1 of this study focuses on the theory of bimodal spherical packing and demonstrates the predictive nature of packing models on the properties of coating systems containing HSPs of two different sizes. This study also examines conditions where the model fails by examining the effect of particle size on coating strength in sytems like thermal paper basecoats where the non-HSP component has a broad particle size distribution, and how these surprising trends can be used to generate better-than-expected thermal printing performance in systems with low HSP/clay ratios. Part 2 of this study focuses on the incorporation of HSPs of different particle sizes into paperboard formulations to affect coating strength and opacity.

scholarly journals Optical, microphysical and compositional properties of the Eyjafjallajökull volcanic ash

2014 ◽  
Vol 14 (9) ◽  
pp. 13271-13300 ◽  
Author(s):  
A. Rocha-Lima ◽  
J. V. Martins ◽  
L. A. Remer ◽  
N. A. Krotkov ◽  
M. H. Tabacniks ◽  
...  
Keyword(s):  
Refractive Index ◽  
Volcanic Ash ◽  
Fine Particles ◽  
Absorption Efficiency ◽  
Particle Sizes ◽  
Air Volume ◽  
Automatic Software ◽  
Compositional Properties ◽  
Size Distribution Of Particles ◽  
Mass Absorption Efficiency

Abstract. Microphysical, optical, and compositional properties of the volcanic ash from the April–May (2010) Eyjafjallajökull volcanic eruption are presented. Samples of the volcanic ash were taken on the ground in the vicinity of the volcano. The material was sieved, re-suspended, and collected on filters, separating particle sizes into coarse and fine modes. The spectral mass absorption efficiency αabs [m2 g−1] was determined for coarse and fine particles in the wavelength range from 300 to 2500 nm. Size distribution of particles on filters was obtained using a semi-automatic software to analyze images obtained by Scanning Electron Microscopy (SEM). The grain density of the volcanic ash was determined as 2.16(13) g cm−3 by measuring the variation of air volume in a system with volcanic ash and air under compression. Using Mie–Lorenz and T-matrix theories, the imaginary part of the refractive index was derived. Results show the spectral imaginary refractive index ranging from 0.001 to 0.005. Fine and coarse particles were analyzed by X-Ray fluorescence for elemental composition. Fine and coarse mode particles exhibit distinct compositional and optical differences.

Synthesis, Properties and Characterization of Red Phosphor Particles of Y2O3:Eu

1997 ◽  
Vol 3 (S2) ◽  
pp. 725-726
Author(s):  
Y. D. Jiang ◽  
Z. L. Wang ◽  
F. Zhang ◽  
H. G. Paris ◽  
C. J. Summers
Keyword(s):  
High Efficiency ◽  
Fine Particles ◽  
Average Diameter ◽  
Structure Characterization ◽  
Europium Oxide ◽  
Particle Sizes ◽  
Properties And Characterization ◽  
Field Emission Displays ◽  
Synthesis Properties ◽  
Commercial Applications

High resolution and high efficiency planar display, one of the national priorities for advanced technologies and commercial applications, require highly efficient phosphor materials with crystalline monodispersive fine particles [1,2]. Europium oxide activated yttrium oxide (Y2O3:Eu) is a potential red-emission phosphor powders to be used in high efficiency electroluminescence and field emission displays. In this paper, a novel hydrolysis technique is employed to prepare phosphor particles of Y2O3: Eu, and the structure characterization is reported.In this synthesis technique, urea reacts with water to release OH−, cations of Y3+ and Eu3+ combine with OH− to form (Y1−xEux)(OH)3 precipitates. Y2O3 particles doped with Eu are formed after the precipitates being fired at a given temperature [3]. The particles prepared by this method are nearly spherical, and have an average diameter of ∼200 nm (Fig. 1). The distribution of particle sizes is narrow, and almost no agglomeration among particles is observed. The particle sizes remain approximately the same before (Fig. 1a) and after (Fig. 1b) being fired at 1200°C.

scholarly journals Size-segregated characteristics of organic carbon (OC), elemental carbon (EC) and organic matter in particulate matter (PM) emitted from different types of ships in China

2020 ◽  
Vol 20 (3) ◽  
pp. 1549-1564 ◽  
Author(s):  
Fan Zhang ◽  
Hai Guo ◽  
Yingjun Chen ◽  
Volker Matthias ◽  
Yan Zhang ◽  
...  
Keyword(s):  
Particle Size ◽  
Elemental Carbon ◽  
Fine Particles ◽  
Particle Mass ◽  
Fuel Oil ◽  
Chemical Compositions ◽  
Particle Sizes ◽  
Heavy Fuel Oil ◽  
Different Types ◽  
Marine Diesel

Abstract. Studies of detailed chemical compositions in particles with different size ranges emitted from ships are in serious shortage. In this study, size-segregated distributions and characteristics of particle mass, organic carbon (OC), elemental carbon (EC), 16 EPA polycyclic aromatic hydrocarbons (PAHs) and 25 n-alkanes measured aboard 12 different vessels in China are presented. The results showed the following. (1) More than half of the total particle mass, OC, EC, PAHs and n-alkanes were concentrated in fine particles with aerodynamic diameter (Dp) < 1.1 µm for most of the tested ships. The relative contributions of OC, EC, PAH and alkanes to the size-segregated particle mass are decreasing with the increase in particle size. However, different types of ships showed quite different particle-size-dependent chemical compositions. (2) In fine particles, the OC and EC were the dominant components, while in coarse particles, OC and EC only accounted for very small proportions. With the increase in particle size, the OC / EC ratios first decreased and then increased, having the lowest values for particle sizes between 0.43 and 1.1 µm. (3) Out of the four OC fragments and three EC fragments obtained in thermal–optical analysis, OC1, OC2 and OC3 were the dominant OC fragments for all the tested ships, while EC1 and EC2 were the main EC fragments for ships running on heavy fuel oil (HFO) and marine-diesel fuel, respectively; different OC and EC fragments presented different distributions in different particle sizes. (4) The four-stroke low-power diesel fishing boat (4-LDF) had much higher PAH emission ratios than the four-stroke high-power marine-diesel vessel (4-HMV) and two-stroke high-power heavy-fuel-oil vessel (2-HHV) in fine particles, and 2-HHV had the lowest values. (5) PAHs and n-alkanes showed different profile patterns for different types of ships and also between different particle-size bins, which meant that the particle size should be considered when source apportionment is conducted. It is also noteworthy from the results in this study that the smaller the particle size, the more toxic the particle was, especially for the fishing boats in China.

Morphological and Electrical Properties of Silicon Dioxide-Based Interdigitated Electrode Arrays

2015 ◽  
Vol 1109 ◽  
pp. 253-256 ◽  
Author(s):  
M.A. Farehanim ◽  
U. Hashim ◽  
Norhayati Soin ◽  
A.H. Azman ◽  
S. Norhafiezah ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Silicon Dioxide ◽  
Ph Value ◽  
Ph Measurement ◽  
Electrode Arrays ◽  
Interdigitated Electrode ◽  
Buffer Solutions ◽  
Ph Values ◽  
Ph Buffer ◽  
Higher Sensitivity

The electrical performances of silicon dioxide-based Interdigitated electrodes (IDEs) as biosensor were developed. The IDEs was made up by two individually addressable Interdigitated comb-like finger structure have frequently been suggested as a biosensor which promises higher sensitivity compared to conventional parallel electrodes. The purpose of this paper was to investigate the capacitance test and impedance test to taken with various pH solution to observe the response of the sensor with different pH values. Purchased pH buffer solutions which varied from pH2 to pH10 are dropped on the microelectrode and the effect on it is investigated for the application in pH measurement. This research has proven that increase in pH value from acidic to alkaline is proportional with capacitance. The measured values of capacitance with respect to each pH concentrations applied during the measurements were repeatable and reproducible.

Effect of Impoundment and Diversion on the Sediment Budget and Nearshore Sedimentation of Southern Indian Lake

1984 ◽  
Vol 41 (4) ◽  
pp. 567-578 ◽  
Author(s):  
R. E. Hecky ◽  
G. K. McCullough
Keyword(s):  
Fine Particles ◽  
Suspended Load ◽  
Constituent Particle ◽  
Shoreline Erosion ◽  
Bed Load ◽  
Particle Sizes ◽  
Fine Silt ◽  
Load Transport ◽  
Bed Load Transport ◽  
Clay Aggregates

Shoreline erosion added an annual average of 4 × 106 t of mineral sediment per year to Southern Indian Lake (postimpoundment area, 2391 km2) during the first 3 yr of impoundment. This erosion increased sedimentary input to the lake by a factor of 20. The lake retained 90% of this eroded material within its basin, and 80–90% of the retained material was deposited nearshore. Despite the production of extremely fine constituent particle sizes, eroding shorelines generated predominantly large clay aggregates, initially transported offshore as bed load. During bed load transport, abrasion of clay aggregates produced fine particles that became suspended. Over 80% of the suspended load is lost to outflows from the lake because the suspended load is primarily fine silt and clay-sized particles, most of which do not settle even under winter ice cover. The extensive nearshore clay aggregate deposits are temporary, and net deposition in these areas will change to net erosion when input of sediment from eroding shorelines ceases. The effects of shoreline erosion on the lake's sediment regime will persist for decades.

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