Nonvibrational Nondiffusional Modes of Motion in Hydrated Calcium Nitrate Melts

Ionic Liquids ◽  
1981 ◽  
pp. 15-26
Author(s):  
Ian M. Hodge ◽  
C. Austen Angell
Keyword(s):  
Calcium Nitrate ◽  
Hydrated Calcium

Glass transition temperature of calcium nitrate-potassium nitrate-water system

1980 ◽  
Vol 45 (7) ◽  
pp. 1896-1902 ◽  
Author(s):  
Jarmila Malá ◽  
Ivo Sláma
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Linear Function ◽  
Calcium Nitrate ◽  
Water System ◽  
Potassium Nitrate ◽  
Concentration Region ◽  
Hydrated Calcium ◽  
Nitrate Solutions

The glass-formig concentration region of the calcium nitrate-potassium nitrate-water system was determined. The glass transition temperature can be in the studied region approximated by a linear function of the salt concentrations. A comparison of the properties of the studied system with the hydrated calcium nitrate and chloride mixture revealed important differences in the effect of different salts on the undercoolability of aqueous calcium nitrate solutions.

Structures of chemically stabilized ceramics

1993 ◽  
Vol 51 ◽  
pp. 924-925
Author(s):  
Pratibha L. Gai ◽  
M. A. Saltzberg ◽  
L.G. Hanna ◽  
S.C. Winchester
Keyword(s):  
High Temperature ◽  
Calcium Nitrate ◽  
Nitrate Hexahydrate ◽  
Chemical Route ◽  
Cubic Form ◽  
Tetragonal Form ◽  
Wet Chemical ◽  
Wet Chemical Route ◽  
Final Composition ◽  
Aluminium Nitrate Nonahydrate

Silica based ceramics are some of the most fundamental in crystal chemistry. The cristobalite form of silica has two modifications, α (low temperature, tetragonal form) and β (high temperature, cubic form). This paper describes our structural studies of unusual chemically stabilized cristobalite (CSC) material, a room temperature silica-based ceramic containing small amounts of dopants, prepared by a wet chemical route. It displays many of the structural charatcteristics of the high temperature β-cristobalite (∼270°C), but does not undergo phase inversion to α-cristobalite upon cooling. The Structure of α-cristobalite is well established, but that of β is not yet fully understood.Compositions with varying Ca/Al ratio and substitutions in cristobalite were prepared in the series, CaO:Al2O3:SiO2 : 3-x: x : 40, with x= 0-3. For CSC, a clear sol was prepared from Du Pont colloidal silica, Ludox AS-40®, aluminium nitrate nonahydrate, and calcium nitrate hexahydrate in proportions to form a final composition 1:2:40 composition.

Ecological and hygienic assessment pollution of surface and groundwater in Transural Region Republic of Bashkortostan

2017 ◽  
pp. 14-17
Author(s):  
Z.B. Baktybaeva ◽  
R.A. Suleymanov ◽  
T.K. Valeev ◽  
N.R. Rakhmatullin
Keyword(s):  
Surface Water ◽  
Calcium Nitrate ◽  
Water Bodies ◽  
Drinking Water Contamination ◽  
Mining Areas ◽  
Relative Contribution ◽  
Quality Of Water ◽  
Republic Of Bashkortostan ◽  
The Republic ◽  
Surface And Groundwater

Carried out ecological and hygienic assessment of pollution of surface and groundwater of mining areas in the Republic of Bashkortostan. Revealed exceeding standards for fishery water bodies and drinking and cultural and community water use, which indicates the potential danger of surface water for the health of the region's population. The greatest relative contribution to the overall pollution of surface water bodies are making manganese (33,0–66,6 %), iron (9,1–15,6 %), calcium (6,5–11,7 %), lead (5,8– 7,2 %). The quality of water used for drinking purposes from decentralized water sources (boreholes, wells, springs), do not always correspond to the hygienic and sanitary-epidemiological requirements. In this case, the highest priority performance of drinking water contamination are increased stiffness, high content of iron, calcium, nitrate, presence cadmium, and hexavalent chromium.

A Design of Experiment Approach to the Synthesis of Alendronate-incorporated Hydroxyapatite

2018 ◽  
Vol 69 (8) ◽  
pp. 1944-1948 ◽  
Author(s):  
Adina Turcu Stiolica ◽  
Maria Viorica Bubulica ◽  
Oana Elena Nicolaescu ◽  
Octavian Croitoru ◽  
Mariana Popescu ◽  
...  
Keyword(s):  
Process Parameters ◽  
Design Of Experiment ◽  
Calcium Nitrate ◽  
Chemical Precipitation ◽  
Synthesis Temperature ◽  
Ripening Time ◽  
Synthesis Design ◽  
N2 Atmosphere ◽  
Addition Rate ◽  
Incorporation Efficiency

A design of experiment (DoE) approach is presented for the optimization of Alendronate-hydroxyapatite nanoparticles� synthesis. The synthesis was performed using the chemical precipitation technique from calcium nitrate, diammonium hydrogen phosphate and alendronate. Synthesis temperature, reactant addition rate and ripening time were chosen as the most relevant experimental factors for our synthesis. Design of Experiments was used in order to measure these conclusive process parameters and their effect on controlling some final nanoparticles parameters, such us: alendronate incorporation efficiency (IncorporationEfficiency, %), hydroxyapatite crystallite size (Size_XRD, nm), hydroxyapatite particle size distribution (Size_DLS, �). Our study found that better HA-AL incorporation efficiency and small nonoparticles can be obtained using the following chemical process parameters: reaction temperature 30oC or smaller, ripening time 108h and addition rate 0.1mol/min. The analysis of more than one nanoparticles characteristics was possible using DoE software, MODDE 9.1. Thus, hydroxyapatite-alendronate incorporation efficiency should be expected to increase with decreasing temperature below 300C, increasing the maturate time at least 108h, at an addition rate of 0.1mol/min, in an N2 atmosphere. The same conditions will ensure nanoparticles small size that would be more desirable for the application of implants.

Fluoride Injury to Cut `Samantha' Roses May Be Reduced by Pulsing with Calcium Nitrate

HortScience ◽  
1990 ◽  
Vol 25 (10) ◽  
pp. 1270-1271 ◽  
Author(s):  
Caroline H. Pearson-Mims ◽  
Virginia I. Lohr
Keyword(s):  
Weight Gain ◽  
Calcium Nitrate ◽  
Flower Longevity ◽  
Fresh Weight ◽  
Flower Opening ◽  
Visual Symptoms ◽  
Flower Quality ◽  
Nitrate Pulse ◽  
Solution Uptake ◽  
Preservative Solutions

Cut `Samantha' roses (Rosa hybrida L.) were placed in deionized water or a 20-mm Ca(NO3)2 pulsing solution for 72 hours. Flowers then were held in preservative solutions containing 0 or 4 mg fluoride/liter. Fresh weight gain, solution uptake, degree of flower opening, and flower longevity were reduced in the presence of fluoride in the holding solution. Visual symptoms of injury and reduced flower quality also were noted in treatments with fluoride. Pulsing improved fresh weight gain and degree of opening of flowers held in solutions containing fluoride. Pulsing also delayed the onset of visual symptoms of fluoride injury. Water uptake for flowers that were pulsed and exposed to fluoride was not different from uptake for flowers exposed to fluoride alone. Flower longevity for roses in all treatments was increased by using the calcium nitrate pulse, but pulsed flowers in fluoride did not survive as long as the control flowers.

Nitrogen Fertilization of Basil

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 481a-481 ◽  
Author(s):  
M. Rangappa ◽  
H.L. Bhardwaj
Keyword(s):  
Moisture Content ◽  
Dry Matter ◽  
Calcium Nitrate ◽  
Control Treatment ◽  
Dry Matter Yield ◽  
Sweet Basil ◽  
Broad Leaf ◽  
Yield Difference ◽  
Optimum N Rate ◽  
N Rates

Sweet basil (Ocimum basilicum) is an important culinary herb in Virginia and other areas. The objective of this study, conducted during 1997, was to determine optimal N rate for fresh and dry matter yield. Seed of Broad Leaf sweet basil were direct-seeded on 18 June in rows 0.75 m apart in a RCBD design with 8 replications. Four N rates (0, 25, 50, and 75 kg N/ha) were used. Calcium nitrate (15.5% N) was used as the fertilizer source. All plants from 1-m row length from middle row of each plot were harvested by hand on 23 Sept. and fresh weights were recorded. The plant material was dried at 70°C for 48 h to record dry weights. The moisture content at harvest was calculated from fresh and dry weights. The fresh yields following 0, 25, 50, and 75 kg N/ha were 3.7, 5.4, 6.4, and 6.8 kg/m2, respectively. The yield difference between two highest N rates was not significant, however, both these rates had significantly higher yield than the two lowest rates. Similar results were also obtained for dry matter yields. The highest N rate of 75 kg N/ha resulted in significantly higher dry matter yield (1.3 kg/m2) as compared to the other three rates. The lowest dry matter yield was obtained after the control treatment (0.6 kg/m2). An opposite relationship between N rate and moisture content was observed when the highest moisture content resulted from control and 50 kg N/ha treatments. These results indicate that optimum N rate for sweet basil in Virginia is 50 to 75 kg/ha.

Viscosity, electrical conductivity and density of the system ammonium nitrate-dimethyl sulphoxide

1984 ◽  
Vol 49 (5) ◽  
pp. 1109-1115
Author(s):  
Jindřich Novák ◽  
Zdeněk Kodejš ◽  
Ivo Sláma
Keyword(s):  
Electrical Conductivity ◽  
Aqueous Solutions ◽  
Ammonium Nitrate ◽  
Transport Properties ◽  
Calcium Nitrate ◽  
Dimethyl Sulphoxide ◽  
Present System ◽  
Empirical Equations ◽  
Concentrated Solutions ◽  
Nitrate Solutions

The density, viscosity, and electrical conductivity of highly concentrated solutions of ammonium nitrate in dimethyl sulphoxide have been determined over the temperature range 10-60 °C and the concentration range 7-50 mol% of the salt. The variations in the quantities as a function of temperature and concentration have been correlated by empirical equations. A comparison is made between the transport properties for the present system, aqueous solutions of ammonium nitrate, and calcium nitrate solutions in dimethyl sulphoxide.

The supercooling ability of calcium nitrate solutions in ethylene glycol

1989 ◽  
Vol 54 (10) ◽  
pp. 2711-2714
Author(s):  
Ivo Sláma ◽  
Jarmila Malá
Keyword(s):  
Thermal Stability ◽  
Ethylene Glycol ◽  
Induction Period ◽  
Calcium Nitrate ◽  
Transformation Diagram ◽  
Temperature Transformation ◽  
Thermal Stability Of ◽  
Nitrate Solutions

The dependence of the induction period of crystallization on the supercooling was determined for the Ca(NO3)2-ethylene glycol system at mole fractions of the former from 0 to 0.049, and treated in terms of the TTT (Time-Temperature-Transformation) diagram. Addition of Ca(NO3)2 to ethylene glycol brings about a substantial increase in the critical induction period of crystallization. The thermal stability of glasses is discussed in terms of the shape and position of the TTT curves.

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