Immobilization Index of Liquid LLW in Cementitious Grouts

1995 ◽  
Vol 412 ◽  
Author(s):  
Sadananda Sahu ◽  
Sidney Diamond
Keyword(s):  
Fly Ash ◽  
Room Temperature ◽  
Liquid Waste ◽  
Chemical Species ◽  
Ionic Species ◽  
Cementitious Materials ◽  
The Other ◽  
Waste Solution ◽  
Low Level ◽  
The Individual

AbstractThe ability of grouts formulated from mixtures of cementitious materials and attapulgite clay to immobilize various chemical species in the projected off-gas waste stream from vitrification of Hanford low level tank wastes was studied. Three different solid blends were evaluated, with cement :fly ash : slag clay weight ratios of 3:3:3:1, 3:0:6:1, and 0:0:9:1. The blended solids were mixed with a simulated low level liquid waste solution containing Na+, NO2-, NO3-, PO43- and OH- ions, in the proportion of 1 liter of solution to 1 kg of solid blend, and were cured either at 22°C (room temperature), 50°C or 90°C. Pore solutions were expressed at various ages and were analyzed to determine the reductions in concentrations of the individual ionic species. The results were expressed in the form of immobilization index (I) calculated for each species. The immobilization indices for Na+ (I Na+ ) and for OH- (IOH-)were similar in each case, and were found to be highest when only slag and clay was present (blend 0:0:9:1). The immobilization index for phosphate, , was 1 in all cases, i.e. phosphate was completely removed from solution. On the other hand removal of NO2- and NO3- ions was generally ineffective.

The Potential Application of Metal Binding Hydro- and Silica-Gels in Low-Level Radioactive Waste Processing

2008 ◽  
Author(s):  
Tadashi Tokuhiro ◽  
Josh W. Carey ◽  
Massimo Bertino ◽  
Akira Tokuhiro
Keyword(s):  
Radioactive Waste ◽  
Metal Binding ◽  
Liquid Waste ◽  
Chemical Species ◽  
Silica Gels ◽  
Waste Processing ◽  
Specific Chemical ◽  
New Approach ◽  
Low Level ◽  
Low Level Radioactive Waste

Within the management of radioactive waste, we sought to consider a new approach radioactive hazardous waste processing in aqueous or similar (low-level waste; LLW) forms LLW and in fact, ‘contaminants of concern’ is often stored as diluted aqueous solutions of radioactive (or non) elements and contained in storage containers. One of the general problems associated with mixed liquid waste is the lack of an efficient, effective, and inexpensive means of processing (separating) its constituents. Two of the objectives in processing solid, radioactive laden liquid LLW are as follows: 1) to separate/extract the radioisotopes from the rest of the mixed constituents, and 2) to produce stable solidified forms encapsulating radioactive elements. Recent R&D in the physical chemistry of gel materials, have identified promising approach to simultaneously achieve the above objectives. That is, by utilizing and manipulating the physicochemical properties of various silica- and polymer-based gels at the nanoscale, we have demonstrated a process by which to specific chemical species are encapsulated.

INDUCED INFRARED ABSORPTION OF DEUTERIUM IN DEUTERIUM – FOREIGN GAS MIXTURES

1966 ◽  
Vol 44 (11) ◽  
pp. 2893-2903 ◽  
Author(s):  
S. T. Pai ◽  
S. Paddi Reddy ◽  
C. W. Cho
Keyword(s):  
Absorption Band ◽  
Binary Mixtures ◽  
Infrared Absorption ◽  
Room Temperature ◽  
The Other ◽  
Absorption Profile ◽  
Absorption Coefficients ◽  
Helium Mixtures ◽  
Experimental Values ◽  
The Individual

The pressure-induced fundamental infrared absorption band of deuterium was studied in deuterium–helium, deuterium–argon, and deuterium–nitrogen mixtures at pressures up to 1 200 atm at room temperature. The enhancement absorption profile of each mixture shows a well-resolved splitting of the Q branch into two components QP and QR. While the enhancement contours of deuterium–helium mixtures do not exhibit any absorption peaks corresponding to the O and S branches, those of the other two binary mixtures show a pronounced S(2) peak and an indication of several other O and S peaks of the band. Integrated absorption coefficients of the band have been measured for all the mixtures, and the binary and ternary absorption coefficients were determined. The theory of Van Kranendonk and the available molecular parameters of deuterium and the perturbing gases were used to calculate the binary absorption coefficients of the individual lines of the O and S branches and of the quadrupole part of the Q branch of the band in all three binary mixtures. Using these calculated values and the experimental values of the total binary absorption coefficients of these mixtures, the overlap parts of the binary absorption coefficients of the Q branch were estimated.

scholarly journals Sulphide oxidation mortar tests for evaluation of the oxidation potential of sulphide-bearing aggregate

2021 ◽  
Author(s):  
Mona El-Mosallamy ◽  
Medhat Shehata
Keyword(s):  
Fly Ash ◽  
Relative Humidity ◽  
Sodium Hypochlorite ◽  
Room Temperature ◽  
Oxidation Potential ◽  
The Other ◽  
Oxidizing Agent ◽  
Sulphate Attack ◽  
Sulphide Oxidation ◽  
Mortar Bar

This paper proposes two new sulphide mortar bar tests. The two tests involve two exposure conditions: the first one relies on soaking the sample in an oxidizing agent (6% sodium hypochlorite) for three hours at room temperature to promote oxidation while the other test adopts a range of temperatures and relative humidity that promote oxidation and sulphate attack. Both tests were effective in discriminating between aggregates with oxidizable sulphide and those without. Moreover, the use of low-calcium fly ash at 25% and slag at 30% reduced the expansion but not to the level of samples with non-sulphide aggregates. On the contrary, 10% of metakaolin produced more expansion.<br>

Electron Spin Resonance of Manganese Nitrate in Diethylacetamide-Water Solution

1981 ◽  
Vol 36 (7) ◽  
pp. 751-758
Author(s):  
V. Kleinmann ◽  
M. Stockhausen
Keyword(s):  
Room Temperature ◽  
Water Solution ◽  
Ion Pairs ◽  
Chemical Species ◽  
Ionic Species ◽  
Esr Spectra ◽  
Ion Pair ◽  
Small Water ◽  
Spin Resonance ◽  
Solvated Ions

Abstract le c tro n S p in R e s o n a n c e o f M a n g a n e se N i t r a t e in D ie th y la c e ta m id e -W a te r S o lu tio n At small water concentrations, ESR spectra at room temperature exhibit distinguishable con­ tributions which are ascribed to the following ionic species: (I) a small fraction of residual manga­ nese ions with mixed amide-water solvation, (II) amide solvated ions (having altered hyperfine splitting and gr-factor due to nitrate in an outer coordination sphere, so that they may be con­ sidered loose ion pairs), (III) tight ion pair species. Presumably, (II) and (III) are not well defined "chemical" species but constituents of fluctuating aggregations.

scholarly journals Sulphide oxidation mortar tests for evaluation of the oxidation potential of sulphide-bearing aggregate

2021 ◽  
Author(s):  
Mona El-Mosallamy ◽  
Medhat Shehata
Keyword(s):  
Fly Ash ◽  
Relative Humidity ◽  
Sodium Hypochlorite ◽  
Room Temperature ◽  
Oxidation Potential ◽  
The Other ◽  
Oxidizing Agent ◽  
Sulphate Attack ◽  
Sulphide Oxidation ◽  
Mortar Bar

This paper proposes two new sulphide mortar bar tests. The two tests involve two exposure conditions: the first one relies on soaking the sample in an oxidizing agent (6% sodium hypochlorite) for three hours at room temperature to promote oxidation while the other test adopts a range of temperatures and relative humidity that promote oxidation and sulphate attack. Both tests were effective in discriminating between aggregates with oxidizable sulphide and those without. Moreover, the use of low-calcium fly ash at 25% and slag at 30% reduced the expansion but not to the level of samples with non-sulphide aggregates. On the contrary, 10% of metakaolin produced more expansion.<br>

scholarly journals Sulphide oxidation mortar tests for evaluation of the oxidation potential of sulphide-bearing aggregate

2021 ◽  
Author(s):  
Mona El-Mosallamy ◽  
Medhat Shehata
Keyword(s):  
Fly Ash ◽  
Relative Humidity ◽  
Sodium Hypochlorite ◽  
Room Temperature ◽  
Oxidation Potential ◽  
The Other ◽  
Oxidizing Agent ◽  
Sulphate Attack ◽  
Sulphide Oxidation ◽  
Mortar Bar

This paper proposes two new sulphide mortar bar tests. The two tests involve two exposure conditions: the first one relies on soaking the sample in an oxidizing agent (6% sodium hypochlorite) for three hours at room temperature to promote oxidation while the other test adopts a range of temperatures and relative humidity that promote oxidation and sulphate attack. Both tests were effective in discriminating between aggregates with oxidizable sulphide and those without. Moreover, the use of low-calcium fly ash at 25% and slag at 30% reduced the expansion but not to the level of samples with non-sulphide aggregates. On the contrary, 10% of metakaolin produced more expansion.<br>

scholarly journals Effect of Curing Temperature on the Properties of Cementitious Waste Forms

1989 ◽  
Vol 176 ◽  
Author(s):  
Ryan O. Lokken ◽  
John W. Shade ◽  
Paul F. C. Martin
Keyword(s):  
Compressive Strength ◽  
High Temperature ◽  
Liquid Waste ◽  
Cementitious Materials ◽  
Curing Temperature ◽  
Curing Time ◽  
Low Level ◽  
Waste Forms ◽  
Liquid Wastes ◽  
Time Periods

ABSTRACTCurrent plans for disposing various low-level radioactive and/or hazardous liquid wastes include solidification of the waste using cementitious materials. One process, known as grouting, involves mixing liquid wastes with a blend of cementitious materials and pumping the resultant slurry to lined, underground concrete vaults. As the grout slurry begins to solidify and harden, the temperature within the grout increases due to exothermic hydration reactions. Depending on the the particular grout composition and on the disposal conditions, the grout may be exposed to temperatures of around 90°C for extended time periods. Studies are being conducted to determine the effects of high-temperature curing on selected properties of grouts prepared with a simulated low-level liquid waste. Grout samples cured at temperatures up to 950C in the laboratory absorbed water during curing. The resultant leach resistance and compressive strength of these grouts decreased with increases in curing temperature and curing time.

Electron microscope studies of the plastic deformation of ternary alloys based on GaAs

1990 ◽  
Vol 48 (4) ◽  
pp. 1120-1120
Author(s):  
R. Haswell ◽  
U. Bangert ◽  
P. Charsley
Keyword(s):  
Plastic Deformation ◽  
Electron Microscope ◽  
Room Temperature ◽  
Stacking Faults ◽  
The Other ◽  
Ternary Alloys ◽  
Dislocation Mobility ◽  
Semiconducting Materials ◽  
Micro Indentation

A knowledge of the behaviour of dislocations in semiconducting materials is essential to the understanding of devices which use them . This work is concerned with dislocations in alloys related to the semiconductor GaAs . Previous work on GaAs has shown that microtwinning occurs on one of the <110> rosette arms after indentation in preference to the other . We have shown that the effect of replacing some of the Ga atoms by Al results in microtwinning in both of the rosette arms.In the work to be reported dislocations in specimens of different compositions of Gax Al(1-x) As and Gax In(1-x) As have been studied by using micro indentation on a (001) face at room temperature . A range of electron microscope techniques have been used to investigate the type of dislocations and stacking faults/microtwins in the rosette arms , which are parallel to the [110] and [10] , as a function of composition for both alloys . Under certain conditions microtwinning occurs in both directions . This will be discussed in terms of the dislocation mobility.

Writing in Aphasia Rehabilitation: Cursive vs Manuscript

1976 ◽  
Vol 41 (4) ◽  
pp. 523-529 ◽  
Author(s):  
Daniel R. Boone ◽  
Harold M. Friedman
Keyword(s):  
Correct Response ◽  
The Other ◽  
Read Aloud ◽  
Writing Style ◽  
Reading And Writing ◽  
Manual Responses ◽  
Significant Difference ◽  
Written Form ◽  
The Individual ◽  
Read Number

Reading and writing performance was observed in 30 adult aphasic patients to determine whether there was a significant difference when stimuli and manual responses were varied in the written form: cursive versus manuscript. Patients were asked to read aloud 10 words written cursively and 10 words written in manuscript form. They were then asked to write on dictation 10 word responses using cursive writing and 10 words using manuscript writing. Number of words correctly read, number of words correctly written, and number of letters correctly written in the proper sequence were tallied for both cursive and manuscript writing tasks for each patient. Results indicated no significant difference in correct response between cursive and manuscript writing style for these aphasic patients as a group; however, it was noted that individual patients varied widely in their success using one writing form over the other. It appeared that since neither writing form showed better facilitation of performance, the writing style used should be determined according to the individual patient’s own preference and best performance.

Margaret Mahy: An Adlerian Reading

2008 ◽  
Vol 1 (2) ◽  
pp. 187-199
Author(s):  
KATHRYN WALLS
Keyword(s):  
Young Female ◽  
The Other ◽  
Individual Psychology ◽  
The Novel ◽  
Alfred Adler ◽  
Female Protagonists ◽  
Magical Power ◽  
Margaret Mahy ◽  
The Individual

According to the ‘Individual Psychology’ of Alfred Adler (1870–1937), Freud's contemporary and rival, everyone seeks superiority. But only those who can adapt their aspirations to meet the needs of others find fulfilment. Children who are rejected or pampered are so desperate for superiority that they fail to develop social feeling, and endanger themselves and society. This article argues that Mahy's realistic novels invite Adlerian interpretation. It examines the character of Hero, the elective mute who is the narrator-protagonist of The Other Side of Silence (1995) , in terms of her experience of rejection. The novel as a whole, it is suggested, stresses the destructiveness of the neurotically driven quest for superiority. Turning to Mahy's supernatural romances, the article considers novels that might seem to resist the Adlerian template. Focusing, in particular, on the young female protagonists of The Haunting (1982) and The Changeover (1984), it points to the ways in which their magical power is utilised for the sake of others. It concludes with the suggestion that the triumph of Mahy's protagonists lies not so much in their generally celebrated ‘empowerment’, as in their transcendence of the goal of superiority for its own sake.

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