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Effects of milling followed by different gradation sizes of lawrencepur sand on the properties of cementitious mortar
(2025-12-01)
Aslam, Hafiz Muhammad Shahzad
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Aslam, Hafiz Muhammad Usman
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Onyelowe, Kennedy C.
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Noshin, Sadaf
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Yasin, Mazhar
The swift rise of urbanization and industrialization has severely depleted natural sand resources and escalated industrial waste accumulation. Environmental damage from over-dredging and limited disposal space has driven researchers to seek alternative solutions. In Lahore, Punjab, Pakistan, coarse pit sand is predominantly used, and overly fine sands from the Ravi and Chenab rivers, which do not meet ASTM grading standards. In this research, Lawrencepur Sand was milled, and its effects on the sand's physical properties and the mortar's mechanical performance were evaluated. For this, comprehensive experimental investigations were conducted, and the mechanical properties of the mortar were assessed at 3, 7, and 28 days. From the experiment, it is clear that milling refines the physical properties of sand by decreasing size, fineness modulus (FM), and absorption, while increasing density and specific gravity, which enhances mortar performance. Milled sand improved mortar density (3.1–11.5 %), compressive strength (10.6–71.4 %), and flexural strength (13.5–48 %), while reducing water absorption by 9–34 %. Excessive milling reduced strength and increased water absorption. SPSS analysis confirmed that milled sand significantly improved mortar performance, with strong statistical validation (p < 0.001). Scanning Electron Microscopy (SEM) and X-ray Diffraction (XRD) analysis also confirmed microstructural densification of mortar by milling, and over-milling led to a decline in performance due to poor packing.
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Effect of ambient temperature and density on the transition of hot temperature combustion to low temperature combustion of commercial diesel and waste plastic diesel in an optical access machine
(2023-12-01)
Aung, Zin Thu
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Charoenphonphanich, Chinda
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Ewphun, Pop Paul
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Kosaka, Hidenori
Alternative diesel production from mixed waste plastic pyrolysis is an effective method for the management of waste plastic and its related costs. The low temperature combustion (LTC) of diesel enables the reduction of nitrogen oxides and soot simultaneously. However, because of the high quantity of unburned hydrocarbon (UHC) and carbon monoxide (CO) emissions, LTC has a low combustion efficiency. This paper investigated the combined effect of low ambient temperature and high density (LATHD) on the transition from hot temperature combustion (HTC) to LTC by using commercial diesel (CD) and waste plastic diesel (WPD) without exhaust gas recirculation (EGR) and low cetane fuels. The results showed that NOx and soot concentrations were decreased and integral heat release was increased. For a given unit heat release, the NOx emissions of CD and WPD decreased 60% and 38%, respectively, by decreasing the ambient temperature from 1050 K to 750 K. Furthermore, integral heat release is a more influential parameter on NOx than heat release rate. After that, soot concentrations of CD and WPD were significantly decreased by 85% and 81% with a reduction in ambient temperature from 1050 K to 750 K. At the same ambient temperature, the NOx and soot concentrations of WPD were higher than that of CD for all cases. With the same ignition delay, however, the NOx and soot concentrations of WPD/high cetane fuel decreased dramatically compared to CD. This information will be useful for determining compression ratio and combustion phasing when considering engine designs.
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Salinity tolerance and nursing performance under different densities in spotted scat Scatophagus argus Linnaeus, 1766
(2023-05-01)
Yangthong, Monsuang
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Suratata, Montathip
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Nontaso, Adjakab
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Ruensirikul, Jirayuth
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Kaneko, Gen
Spotted scat Scatophagus argus is a euryhaline species generally nursed in brackish water and shipped to freshwater ponds or sea cages of local farms in Thailand. To find the best practice for this process in terms of survival and cost, we conducted two culture experiments. In experiment 1, spotted scat fries (up to 6.72 ± 2.15 g) were divided into 5 size classes (S1–S5), and their survival rates were determined after 4 patterns of salinity changes [from 0 to 30 parts per thousand (ppt), from 0 to 15 ppt, and vice versa]. The survival rates were not significantly different between groups when fries were transferred from or to 15 ppt water. However, smaller fries (S1–S3) presented lower survival rates than larger fries (S4 and S5) when transferred from 0 to 30 ppt. In experiment 2, fries (0.21 ± 0.05 g) were nursed at three densities (125, 250, and 500 fish/m3) using underground water without water changes for 80 days. The 125 and 250 fish/m3 groups showed similar culture performance, suggesting that the nursing density can be up to 250 fish/m3 under these conditions. These results provide empirical data for establishing the best nursery practice of spotted scat, which will be particularly useful for small-scale farmers.
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Computational analysis of blood parameters separate by centrifuge technique
(2017-03-23)
Wangboon, Anon
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Phasukkit, Pattarapong
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Keawbumrung, Mongkol
This article is purpose of the computational fluid dynamic (CFD) simulation for blood parameters separated by centrifuge machine which has different spinning velocities. The structure of the machine, as a fixed tube at 30 degrees from the base is used to prove that the precipitate of the blood's 2 parameters, such as blood cell and plasma, by using the simulation from computer In three dimensional (3D) symmetry modeling to study the change of the precipitate in centrifuge at different velocity of spinning. At 2000 rpm, 3000 rpm, 4000 rpm and 5000 rpm(round per minute) the result of this simulation showed the density of blood as low density in the top of the blood it's mean plasma and high density at the bottom of the tube it's mean blood cell. From the model in centrifuge can prove that in each different level of the density from velocity of spinning that useful for study to improvement of blood parameters separated by used computer simulation.
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The uncertainty in sugar solution concentration measurement based on density approach
(2013-11-04)
Klongratog, B.
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Suesut, T.
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Nunak, N.
The concentration of solution used in osmotic process is an important factor to dehydrate water from food, which is an effect to the rate of mass transfer. Therefore, the in line measurement and control of the concentration in osmotic process is taken into account. The density of sugar solution can be computed by volume and weight in order to determine the concentration in degree of Brix. This instrument will complete when accompanied by a statement of its uncertainty. The calibration equation established the relationship between the reading values of sensor and the values of concentration also need to clarify. The objective of this paper is to evaluate the uncertainty of predicted values of calibration equation; therefore, the uncertainty is determined in this study, and to compare the obtained results from the classical method in linear equation and the inverse method. Furthermore, the data from Monte Carlo simulations also are compared to the measured data. © (2013) Trans Tech Publications, Switzerland.

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