Removal of high-concentration of arsenic in acidic wastewater through zero-valent aluminium powder and characterisation of products

2021 ◽  
pp. 105767
Author(s):  
Tianqi Liao ◽  
Hongtao Qu ◽  
Te Zhang ◽  
Yongguang Luo ◽  
Libo Zhang ◽  
...  
Keyword(s):  
High Concentration ◽  
Aluminium Powder ◽  
Acidic Wastewater

Horizontal jets and vortex dipoles in a stratified fluid

1991 ◽  
Vol 227 ◽  
pp. 543-566 ◽  
Author(s):  
S. I. Voropayev ◽  
Ya. D. Afanasyev ◽  
I. A. Filippov
Keyword(s):  
Fluid Flows ◽  
Stratified Fluid ◽  
Theoretical Explanation ◽  
Thymol Blue ◽  
High Concentration ◽  
Governing Parameter ◽  
Aluminium Powder ◽  
Density Distributions ◽  
Vortex Dipoles ◽  
Short Period

When a horizontal force is applied locally to some volume of a viscous densitystratified fluid, flows with high concentration of vertically oriented vorticity (vortex dipoles) are generated. The processes of generation and evolution with time of these unsteady flows in a stratified fluid are studied. A convenient way to produce and study these flows in the laboratory is to use a submerged horizontal jet as a ‘point’ source of momentum. The main governing parameter (the ‘force’) is easily controlled in this case. Two regimes were studied: starting jets with dipolar vortex fronts (the force acts continuously) and impulsive vortex dipoles (the force acts for a short period of time). A conductivity microprobe, aluminium powder, shadowgraph, thymol-blue and other techniques have been used to measure the velocity and density distributions in the flows. It is found that in both regimes the flows are self-similar: the lengthscale of the flows increases with time as t½ for starting jets and as t1/3 for vortex dipoles. Detailed information about the generation mechanism, kinematics and dynamics of the flows is obtained. On the basis of similarity principles a theoretical explanation of the experimental results is given. The theory is in good agreement with the results obtained.

scholarly journals Color ruler to confirm spectrophotometer results for nitro compound content in acidic wastewater from TNT processes

2021 ◽  
Author(s):  
Ahmed Mahjoub ◽  
Osman Eltayeb
Keyword(s):  
Nitro Compound ◽  
Colorimetric Analysis ◽  
High Concentration ◽  
Reference Procedure ◽  
Low Concentration ◽  
Single Beam ◽  
Sample Concentration ◽  
Acidic Wastewater ◽  
Analytical Reference

This study aimed to find an additional analytical reference procedure to verify the accuracy of single beam Spectrophotometer results that used to determine the concentration of nitro compound pollutants such as TNT, DNT, and MNT (Tri Nitro Toluene, Di Nitro toluene, and Mono Nitro Toluene respectively) in treated acidic wastewater generated from TNT manufacturing. This procedure was tested and confirmed to be a reference for a single-beam spectrophotometer. In this study 10 samples with known concentrations were taken and prepared for colorimetric analysis, the concentrations gradient from 10mg/L up to 60mg/L to make a ruler with gradient color, this ruler was suitable for high concentration samples but to specify the low concentration samples the procedure depended on adding a known concentration to the unknown concentration sample then this added concentration transferred the samples from unspecified color to specified color on the ruler consisted by known concentration mentioned above, the concentration of unknown concentration samples were specified by taking the concentration corresponding to the ruler color a subtracting the value of added concentration and the value of the remains was sample concentration. This study proved the reliability of this procedure to confirm single-beam spectrophotometer results, determining low concentration value of unknown concentration sample of TNT acidic wastewater, and then it can be used as a substituent of spectrophotometer in the event of malfunctions.

Cytomembrane Preservation in Tissue Dehydrated Only With Glutaraldehyde and Epon 812 Resin

1973 ◽  
Vol 31 ◽  
pp. 320-321
Author(s):  
Daniel C. Pease
Keyword(s):  
Diffraction Pattern ◽  
X Ray Diffraction ◽  
High Concentration ◽  
Unpublished Study ◽  
X Ray ◽  
Sectioned Material

A previous study demonstrated that tissue could be successfully infiltrated with 50% glutaraldehyde, and then subsequently polymerized with urea to create an embedment which retained cytomembrane lipids in sectioned material. As a result, the 180-190 Å periodicity characteristic of fresh, mammalian myelin was preserved in sections, as was a brilliant birefringence, and the capacity to bind OsO4 vapor in the hydrophobic bilayers. An associated (unpublished) study, carried out in co-operation with Drs. C.K. Akers and D.F. Parsons, demonstrated that the high concentration of glutaraldehyde (and urea) did not significantly alter the X-ray diffraction pattern of aldehyde-fixed, myelin. Thus, by itself, 50% glutaraldehyde has little effect upon cytomembrane systems and can be used with confidence for the first stages of dehydration.

Effects of carbamylcholine on chick embryo aggregate retina cell cultures

1988 ◽  
Vol 46 ◽  
pp. 350-351
Author(s):  
Glenn M. Cohen ◽  
Radharaman Ray
Keyword(s):  
Cell Cultures ◽  
Single Cells ◽  
Retinal Cell ◽  
Cell Aggregates ◽  
High Concentration ◽  
In Ovo ◽  
Sterile Culture ◽  
Retinal Tissue ◽  
Synaptic Junctions ◽  
And Control

Retinal,cell aggregates develop in culture in a pattern similar to the in ovo retina, forming neurites first and then synapses. In the present study, we continuously exposed chick retinal cell aggregates to a high concentration (1 mM) of carbamylcholine (carbachol), an acetylcholine (ACh) analog that resists hydrolysis by acetylcholinesterase (AChE). This situation is similar to organophosphorus anticholinesterase poisoning in which the ACh level is elevated at synaptic junctions due to inhibition of AChE, Our objective was to determine whether continuous carbachol exposure either damaged cholino- ceptive neurites, cell bodies, and synaptic elements of the aggregates or influenced (hastened or retarded) their development.The retinal tissue was isolated aseptically from 11 day embryonic White Leghorn chicks and then enzymatically (trypsin) and mechanically (trituration) dissociated into single cells. After washing the cells by repeated suspension and low (about 200 x G) centrifugation twice, aggregate cell cultures (about l0 cells/culture) were initiated in 1.5 ml medium (BME, GIBCO) in 35 mm sterile culture dishes and maintained as experimental (containing 10-3 M carbachol) and control specimens.

The Fine Structure of Phloem Cells

1985 ◽  
Vol 43 ◽  
pp. 632-635
Author(s):  
James Cronshaw
Keyword(s):  
Structural Studies ◽  
High Concentration ◽  
Long Distance ◽  
Phloem Tissue ◽  
Sieve Elements ◽  
Long Distance Transport ◽  
P Protein ◽  
Companion Cells ◽  
Electron Microscopical ◽  
Distance Transport

Long distance transport in plants takes place in phloem tissue which has characteristic cells, the sieve elements. At maturity these cells have sieve areas in their end walls with specialized perforations. They are associated with companion cells, parenchyma cells, and in some species, with transfer cells. The protoplast of the functioning sieve element contains a high concentration of sugar, and consequently a high hydrostatic pressure, which makes it extremely difficult to fix mature sieve elements for electron microscopical observation without the formation of surge artifacts. Despite many structural studies which have attempted to prevent surge artifacts, several features of mature sieve elements, such as the distribution of P-protein and the nature of the contents of the sieve area pores, remain controversial.

Tem analysis of multiple-energy arsenic implanted and Rta'd silicon

1987 ◽  
Vol 45 ◽  
pp. 246-247
Author(s):  
R.A. Herring
Keyword(s):  
Device Fabrication ◽  
High Concentration ◽  
Tem Analysis ◽  
Defect Clusters ◽  
High Fluences ◽  
Small Defect ◽  
Before And After ◽  
The Matrix ◽  
The Difference ◽  
Factor Type

Rapid thermal annealing (RTA) of ion-implanted Si is important for device fabrication. The defect structures of 2.5, 4.0, and 6.0 MeV As-implanted silicon irradiated to fluences of 2E14, 4E14, and 6E14, respectively, have been analyzed by electron diffraction both before and after RTA at 1100°C for 10 seconds. At such high fluences and energies the implanted As ions change the Si from crystalline to amorphous. Three distinct amorphous regions emerge due to the three implantation energies used (Fig. 1). The amorphous regions are separated from each other by crystalline Si (marked L1, L2, and L3 in Fig. 1) which contains a high concentration of small defect clusters. The small defect clusters were similar to what had been determined earlier as being amorphous zones since their contrast was principally of the structure-factor type that arises due to the difference in extinction distance between the matrix and damage regions.

Influence of nascent polypeptide positive charges on translation dynamics

2020 ◽  
Vol 477 (15) ◽  
pp. 2921-2934
Author(s):  
Rodrigo D. Requião ◽  
Géssica C. Barros ◽  
Tatiana Domitrovic ◽  
Fernando L. Palhano
Keyword(s):  
Mrna Decay ◽  
Translation Termination ◽  
Published Data ◽  
Translation Efficiency ◽  
Amino Acid Residues ◽  
High Concentration ◽  
Strong Argument ◽  
Translation Arrest ◽  
Exit Tunnel ◽  
Positively Charged

Protein segments with a high concentration of positively charged amino acid residues are often used in reporter constructs designed to activate ribosomal mRNA/protein decay pathways, such as those involving nonstop mRNA decay (NSD), no-go mRNA decay (NGD) and the ribosome quality control (RQC) complex. It has been proposed that the electrostatic interaction of the positively charged nascent peptide with the negatively charged ribosomal exit tunnel leads to translation arrest. When stalled long enough, the translation process is terminated with the degradation of the transcript and an incomplete protein. Although early experiments made a strong argument for this mechanism, other features associated with positively charged reporters, such as codon bias and mRNA and protein structure, have emerged as potent inducers of ribosome stalling. We carefully reviewed the published data on the protein and mRNA expression of artificial constructs with diverse compositions as assessed in different organisms. We concluded that, although polybasic sequences generally lead to lower translation efficiency, it appears that an aggravating factor, such as a nonoptimal codon composition, is necessary to cause translation termination events.

Measurement of the Platelet Response to Laser- induced Microvascular Injury

1974 ◽  
Vol 32 (02/03) ◽  
pp. 704-713 ◽  
Author(s):  
F. N McKenzie ◽  
K.-E Arfors ◽  
N. A Matheson
Keyword(s):  
Inhibitory Effect ◽  
Microvascular Blood Flow ◽  
Platelet Response ◽  
High Concentration ◽  
Platelet Activity ◽  
Microvascular Injury ◽  
Arterial Blood ◽  
Proximal Site ◽  
Adenosine Phosphates

SummaryA study has been made of the biochemical factors underlying the platelet response to laser-induced microvascular injury. A platelet aggregating substance is produced at sites of laser-induced injury which markedly stimulates platelet activity at a site of injury inflicted a short distance downstream. Distal sites of injury are not similarly influenced if the distance between the injuries is increased or if the proximal site no longer shows platelet-stimulating activity. The stimulating effect of an adjacent proximal injury on platelet activity at a distal site is inhibited by local intra-arterial infusion of adenosine. Measurements of arterial blood pressure and microvascular blood flow velocity during adenosine infusion showed that its inhibitory effect on platelet activity is largely independent of its vasodilator properties. The effect of infusion of different adenosine phosphates (AMP, ADP, ATP) was also studied. Very small amounts of ADP markedly stimulated platelet activity and the emboli formed were similar to those normally produced at sites of laser injury. At high concentration AMP inhibited while ATP stimulated platelet activity in vivo. The results emphasise the fundamental role of ADP as a mediator of the platelet response at sites of laser- induced microvascular injury.

An Evaluation of a Plasma Fractionation System

1960 ◽  
Vol 4 (01) ◽  
pp. 031-044
Author(s):  
George Y. Shinowara ◽  
E. Mary Ruth
Keyword(s):  
Biological Activity ◽  
Ionic Strength ◽  
Plasma Proteins ◽  
High Concentration ◽  
Significant Evidence ◽  
Native Proteins ◽  
Mobility Data ◽  
Fractionation Procedure ◽  
The Individual ◽  
Low Ionic Strength

SummaryFour primary fractions comprising at least 97 per cent of the plasma proteins have been critically appraised for evidence of denaturation arising from a low temperature—low ionic strength fractionation system. The results in addition to those referable to the recovery of mass and biological activity include the following: The high solubilities of these fractions at pH 7.3 and low ionic strengths; the compatibility of the electrophoretic and ultracentrifugal data of the individual fractions with those of the original plasma; and the recovery of hemoglobin, not hematin, in fraction III obtained from specimens contaminated with this pigment. However, the most significant evidence for minimum alterations of native proteins was that the S20, w and the electrophoretic mobility data on the physically recombined fractions were identical to those found on whole plasma.The fractionation procedure examined here quantitatively isolates fibrinogen, prothrombin and antithrombin in primary fractions. Results have been obtained demonstrating its significance in other biological systems. These include the following: The finding of 5 S20, w classes in the 4 primary fractions; the occurrence of more than 90 per cent of the plasma gamma globulins in fraction III; the 98 per cent pure albumin in fraction IV; and, finally, the high concentration of beta lipoproteins in fraction II.

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