Effects of filtration temperature, humic acid level and alum dose on cryptosporidium sized particle breakthrough

2006 ◽  
Vol 54 (11-12) ◽  
pp. 353-361
Author(s):  
G.R. Xu ◽  
C.S.B. Fitzpatrick ◽  
L.Y. Deng
Keyword(s):  
High Temperature ◽  
Humic Acid ◽  
Acid Level ◽  
Low Dose ◽  
Optimal Dose ◽  
Influence Of Temperature ◽  
Ζ Potential ◽  
Before And After ◽  
Higher Temperature ◽  
Lower Temperature

Recent Cryptosporidium outbreaks have highlighted concerns about filter efficiency and especially particle breakthrough. Understanding the causes of breakthrough is essential, as the parasite cannot be destroyed by conventional disinfection with chlorine. Particle breakthrough depends on many factors. This research aims to investigate the influence of temperature, humic acid (HA) level and chemical dosing on particle breakthrough in filtration. A series of temperatures were set at 5 °C, 15 °C and 25 °C; humic acid level was 5 mg L−1. Each was combined with a series of Al doses. A laser particle counter was used to assess the particle breakthrough online. Turbidity, ζ potential, and UV254 absorption were measured before and after filtration. The results showed that particle breakthrough was influenced significantly by temperature, humic acid and dosing. Particle breakthrough occurred earlier at lower temperature, while at higher temperature it was reduced at the same coagulant dose. With coagulants, even at low dose, particle breakthrough was significantly reduced. With HA 5 mg L−1, particle breakthrough was earlier and the amount was much larger than without HA even at high temperature. There was an optimal dose in filtration and it was well correlated with ζ potential.

Investigation on Toughness of Fibre Cocktail Reinforced Self Consolidating Concrete after High Temperature

2010 ◽  
Vol 650 ◽  
pp. 67-77
Author(s):  
Yi Ning Ding ◽  
Yue Hua Wang ◽  
Yu Lin Zhang
Keyword(s):  
High Temperature ◽  
High Performance ◽  
Steel Fibers ◽  
Failure Pattern ◽  
Self Consolidating Concrete ◽  
Pull Out ◽  
Hybrid Fibre ◽  
Before And After ◽  
Higher Temperature ◽  
Lower Temperature

The effect of different fibres on the residual load-bearing capacity and the failure pattern of high-performance self consolidating concrete (HPSCC) after exposure to high temperature hass been studied in this work. The polypropylene fibers mitigate the spalling of HPSCC element clearly, but did not show clear effect on the mechanic properties of concrete. The macro steel fiber reinforced HPSCC showed higher flexural toughness and ultimate load before and after high temperatures. The mechanical properties of hybrid fibre reinforced HPSCC (HFHPSCC) after heating were better than that of mono-fibre reinforced HPSCC. The failure mode changed from pull-out of steel fibers at lower temperature to broken down of steel fibers at higher temperature. The use of hybrid fibre can be effective in providing the residual strength and failure pattern, and improving the toughness of HPSCC after high temperature.

Effects of high temperature on the growth and composition of sugarcane internodes

2006 ◽  
Vol 57 (10) ◽  
pp. 1087 ◽  
Author(s):  
G. D. Bonnett ◽  
M. L. Hewitt ◽  
D. Glassop
Keyword(s):  
High Temperature ◽  
Soluble Sugars ◽  
Dry Mass ◽  
Temperature Treatment ◽  
Sucrose Content ◽  
Insoluble Fibre ◽  
Higher Temperature ◽  
Lower Temperature ◽  
Leaf Appearance ◽  
Possible Cause

Sugarcane grown in the Ord River district of Western Australia has lower sucrose content than expected from earlier trials and experience in other irrigated districts. High temperatures have been hypothesised as a possible cause. The effects of high temperature (above 32°C) on growth and carbon partitioning were investigated. A temperature regime of (25–38°C) was compared with (23–33°C). In one experiment, 7-month-old plants of cvv. Q117 and Q158 were subjected to the treatments for 2 months. In another experiment, the plants were allowed to regrow (ratoon) for 6 months. In both experiments, the higher temperature resulted in more, shorter internodes and higher moisture content. Most internodes from plants in the higher temperature treatment had lower sucrose content than internodes from the lower temperature. On a dry mass basis the internodes from the plants in the higher temperature had proportionately more fibre and hexoses but lower sucrose. Combined with an increased number of nodes in a stem of similar or shorter length this would result in higher stalk fibre and lower sucrose content. The data provided evidence that sugarcane partitions less carbon to stored sucrose when grown under high compared with low temperatures. The two cultivars partitioned carbon between soluble (sugars) and insoluble (fibre) fractions to different degrees. These experiments also indicate that the current models describing leaf appearance and perhaps sugarcane growth at temperatures above 32°C, in general, need revision.

Study of mechanical properties and subsurface damage of quartz glass at high temperature based on MD simulation

2019 ◽  
Vol 04 (02) ◽  
pp. 1950003 ◽  
Author(s):  
Xiaoguang Guo ◽  
Chong Chen ◽  
Renke Kang ◽  
Zhuji Jin
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
High Temperature ◽  
Quartz Glass ◽  
Subsurface Damage ◽  
Simulation Based ◽  
Glass Model ◽  
Crystal Model ◽  
Higher Temperature ◽  
Lower Temperature

The mechanical properties (hardness, elastic modulus) and subsurface damage of quartz glass at high temperature are studied by nanoindentation simulation based on molecular dynamics (MD). By heating the quartz crystal model to 3000[Formula: see text]K and annealing to 300[Formula: see text]K twice, the quartz glass model is prepared. According to the nanoindentation simulation results, the hardness of quartz glass decreases by 53.6% and the elastic modulus increases by 10.9% at 1500[Formula: see text]K compared to those at 300[Formula: see text]K. When the temperature rises from 300[Formula: see text]K to 1500[Formula: see text]K, the critical grinding depth of quartz glass increases from nanoscale to micron-scale. The investigation of subsurface damage shows that the damaged layer thickness decreases slightly with the increase of temperature. The damaged layer extends downward under the indenter at lower temperature and extends along the indenter at higher temperature.

Crystallisation of amorphous Mg-Fe silicates produced from microwave-dried sol-gels

2019 ◽  
Vol 15 (S350) ◽  
pp. 408-409
Author(s):  
Stephen P. Thompson ◽  
Anna Herlihy ◽  
Claire A. Murray ◽  
Annabelle R. Baker ◽  
Sarah J. Day
Keyword(s):  
High Temperature ◽  
Powder Diffraction ◽  
Protoplanetary Disks ◽  
Activation Energies ◽  
X Ray ◽  
Higher Temperature ◽  
Lower Temperature

AbstractAmorphous Mg-Fe silicates are produced from microwave-dried sol-gels and their thermal crystallisation is studied via in situ synchrotron X-ray powder diffraction. Mg-pyroxene crystallised to forsterite, enstatite and cristobalite. The inclusion of 10% Fe formed only forsterite at much higher temperature, while pure Mg-olivine crystallised at a lower temperature than Mg-pyroxene. Cristobalite is observed as a high-temperature crystallite in the pure-Mg compositions. Crystallisation activation energies are derived and discussed in relation to protoplanetary disks.

scholarly journals Effect of high temperature stress on the performance of twelve sweet pepper genotypes

1970 ◽  
Vol 35 (3) ◽  
pp. 525-534 ◽  
Author(s):  
SR Saha ◽  
MM Hossain ◽  
MM Rahman ◽  
CG Kuo ◽  
S Abdullah
Keyword(s):  
High Temperature ◽  
Temperature Stress ◽  
Reproductive Behaviour ◽  
Sweet Pepper ◽  
High Temperature Stress ◽  
Fruit Weight ◽  
Temperature Regimes ◽  
Higher Temperature ◽  
Heat Tolerant ◽  
Lower Temperature

A study on heat tolerance in sweet pepper was conducted at the Asian Vegetable Research and Development Centre (AVRDC), Taiwan from December 1999 to May 2000. Experiments were carried out to investigate the influence of 29/23°C and 24/18°C stress on 12 sweet pepper genotypes on growth, development, reproductive behaviour and yield potentialities and to verify the results of the phytotron study. Performance of 12 sweet pepper genotypes was evaluated under two different temperature regimes of 24/18° C and 29/23° C in the phytotron. Plant height was found higher at 29/23° C compared to 24/18° C. High temperature reduced percent fruit set as well as size of fruits. Individual fruit weight was higher (7.44-125.00 g) when grown at 24/18°C and lower (5.35-103.80 g) at 29/23°C. Out of 12 genotypes, SP00l, SP002, SP004, and SP012 performed poor in respect of per plant yield at higher temperature compared to the lower temperature. So, these four genotypes were considered to be heat sensitive than the others. Leaf proline content of the sensitive genotypes decreased under the high temperature conditions and the heat tolerant lines produced higher amount of proline indicating the role of proline in expressing the heat tolerant capability of sweet pepper genotypes concerned. Keywords: High temperature stress; performance; sweet pepper. DOI: 10.3329/bjar.v35i3.6459Bangladesh J. Agril. Res. 35(3) : 525-534

scholarly journals The Coupled Effect of Temperature and Carbonation on the Corrosion of Rebars in the Simulated Concrete Pore Solutions

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Jiezhen Hu ◽  
Xuequn Cheng ◽  
Xiaogang Li ◽  
Peichang Deng ◽  
Gui Wang
Keyword(s):  
High Temperature ◽  
Electrochemical Impedance ◽  
Ph Value ◽  
Concrete Structures ◽  
Open Circuit ◽  
Effect Of Temperature ◽  
Coupled Effect ◽  
Latitude Region ◽  
Higher Temperature ◽  
Lower Temperature

The reinforced concrete structures have to survive high temperature and carbonation at low latitude region. The research on the effect of temperature and the effect of carbonation are vital to the corrosion of the rebars in concrete structures. The coupled effect of temperature and carbonation on the corrosion of rebars was researched by using the open circuit potential (OCP), the electrochemical impedance spectroscopy (EIS), and the potentiodynamic polarization (PP) measurement in the simulated concrete pore solutions (SPSs). The high temperature environment is conducive to the formation of passivated surface of rebars in SPSs, but the dissolution velocity of passivated surface is higher. The rebars have the greater capacity of passivity at lower temperature. The corrosion rate of rebars at higher temperature is smaller in moderate pH value (10.6) SPSs. The rebars suffer from serious corrosion in the pH = 9.6 SPSs at 318 K temperature.

scholarly journals INFLUENCE OF TEMPERATURE UPON THE VELOCITY OF THE COMPLEMENT FIXATION REACTION IN SYPHILIS

1918 ◽  
Vol 28 (3) ◽  
pp. 297-303 ◽  
Author(s):  
Hideyo Noguchi
Keyword(s):  
Guinea Pig ◽  
Complement Fixation ◽  
Insoluble Fraction ◽  
Optimum Temperature ◽  
Influence Of Temperature ◽  
Maximum Reaction ◽  
Reaction Proceeds ◽  
Higher Temperature ◽  
Fixation Reaction ◽  
Lower Temperature

Examination of syphilitic serum or cerebrospinal fluid can be made at any temperature between 23° and 37°C. The velocity of the fixation reaction, including the fixation of complement and subsequent hemolysis, is greater at a higher temperature, the optimum point being 37°C. The maximum reaction is also reached, however, when the mixture of lipoids, syphilitic serum, and complement is allowed to stand for a long enough period at a lower temperature, the minimum thermal point being near 23°C. For the optimum temperature (37°C.) an incubation of 30 minutes is sufficient, while for the minimum temperature (23°C.) 2 hours are necessary. At the temperature of 30°C. the reaction proceeds with moderate velocity and is complete within 60 minutes. Guinea pig complement gave a sharper reaction with the sera which contained less than one unit of the fixing substance. Fixation is complete, however, at any of the three temperatures within 20 minutes when there are more than two units present. A serum containing one unit of fixing substance will complete reaction within 30 minutes at 37°C., 60 minutes at 30°C., and 2 hours at 23°C., irrespective of whether human or guinea pig complement is used. For many reasons a properly adjusted thermostat for 37°C. is recommended for conducting the serum diagnosis of syphilis when possible, but it should not be overlooked that at a temperature near 30°C. an entirely reliable result can be obtained without a special incubator. Even at a temperature as low as 23°C. the test can be carried out if sufficient length of time is allowed. The foregoing conclusions refer only to the systems in which the acetone-insoluble fraction of tissue lipoids is used as antigen.

Reduction of Secondary Defects in High Energy O-Implanted Si by High Energy Si Irradiation

1992 ◽  
Vol 279 ◽  
Author(s):  
S. L. Ellingboe ◽  
M. C. Ridgway
Keyword(s):  
High Temperature ◽  
Defect Structure ◽  
Low Dose ◽  
Defect Formation ◽  
Volume Fraction ◽  
High Energy ◽  
High Dose ◽  
High Temperature Annealing ◽  
Before And After ◽  
Secondary Defect

ABSTRACTThe effect of 4.2 MeV, low dose Si irradiation before annealing of 1 MeV, high dose O-implanted Si has been studied. Si irradiation results in differences in the defect structure both before and after high temperature annealing. With no Si irradiation, annealing results in polycrystalline Si (polySi) formation and microtwinning at the front SiO2/Si interface. With Si irradiation, the polySi volume fraction is greatly reduced after annealing, twinned Si having grown in its place. Si irradiation has no effect on Si inclusions within the SiO2 layer. The dependence of secondary defect formation on Si dose and implant temperature is presented. In particular, Si irradiation at low implant temperatures (150°C) and moderate doses (5×1016 cm−2) is shown to be most effective in the reduction of the polySi volume fraction at the front SiO2/Si interface.

scholarly journals Back-reacted saponite in Jurassic mudstones and limestones intruded by a Tertiary sill, Isle of Skye

Clay Minerals ◽  
2005 ◽  
Vol 40 (3) ◽  
pp. 263-282 ◽  
Author(s):  
S. J. Kemp ◽  
C. A. Rochelle ◽  
R. J. Merriman
Keyword(s):  
High Temperature ◽  
Thermal Effects ◽  
Mineral Assemblage ◽  
Fracture System ◽  
Detailed Understanding ◽  
Higher Temperature ◽  
Lower Temperature ◽  
Host Rocks ◽  
Grossular Garnet ◽  
Isle Of Skye

AbstractThe Lòn Ostatoin stream section, Trotternish Peninsula, Isle of Skye, exposes a sequence of Middle Jurassic mudstones and limestones which have been locally metasomatized by a transgressive sill of Tertiary age. Limestones in the sequence, including some previously reported as bentonite, have been altered to an unusual assemblage of grossular garnet and saponite clay. The mudstones also contain large proportions of saponite together with pyroxene and zeolites. Saponite also occurs within the basalt intrusion. Grossular and pyroxene represent artifacts of relatively high-temperature assemblages that formed during an early phase of alteration. As the intrusion and adjacent altered country rocks cooled, lower-temperature fluids flowed through a late set of contraction (micro)fractures. Back-reacted saponite, analcime and clinoptilolite were formed, possibly as alteration products of the unstable higher-temperature minerals. The lower-temperature mineral assemblage eventually sealed the late fracture system.This paper highlights an important concept for the study of analogue sites used to investigate thermal effects on engineered liners or barrier host rocks for the landfill and radioactive-waste industries. This is that the original thermally altered mineral assemblage may be overprinted by later, lower-temperature back-reactions. A detailed understanding of both processes is necessary in order to construct a sensible model for the thermal and mineralogical evolution of the site.

Annealing-Induced Transformation of Defects in ZnO Single Crystal and the Effects on the Optical Properties

2013 ◽  
Vol 341-342 ◽  
pp. 311-314
Author(s):  
Wei Feng Li ◽  
Xi Qi Feng
Keyword(s):  
Optical Properties ◽  
Optical Transmittance ◽  
Defect Complexes ◽  
Interstitial Zinc ◽  
Air Atmosphere ◽  
Zinc Interstitial ◽  
Before And After ◽  
Higher Temperature ◽  
Zno Crystal ◽  
Lower Temperature

ZnO single crystals were prepared and then sequentially annealed from 573 to 1073 K in air atmosphere. Optical transmittance spectra (OTS), X-ray excited luminescence (XEL), and photoluminescence (PL) were measured before and after each step of annealing. The lower temperature annealing can enhance the emission but hardly affect the optical transmittance. Contrarily, higher temperature treatments ameliorated the transmittance but degraded emission. Based on experimental results, the blue and green emissions, as well as the 400-500-nm absorption were assigned to isolated zinc interstitial, zinc vacancy and oxygen vacancy in ZnO, respectively. In addition, the defect complexes play important role on optical properties of ZnO crystal. Our results provide further insight into understanding defects and defect complexes in ZnO crystals.

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