Amount Of Insoluble Residue Research Articles

Chemical and physical control processes on the development of caves in the Injana Formation, Central Iraq

The caves that are present within the Injana Formation (Upper Miocene–Pliocene) which sometimes extend to be hosted within the Dibdibba Formation (Pliocene–Pleistocene) in the Tar Al-Najaf and Tar Al-Sayyed within the Najaf–Karbala district have been studied. The study aims to assess the genesis of caves and diagnose the factors affecting the building and the destruction of these caves through geologic time. For this reasons, intensive fieldwork as well as the mineralogical composition and microscopic interpretation were achieved to facilitate the investigation of cave-forming factors. Calcite, quartz, feldspar, dolomite, as well as clay minerals are the constituents of Injana Formation in the study area. The amount of insoluble residue is usually higher in weathered carbonates and in some other cases in fresh carbonate, which is not very common but it may occur. Caves appear to be hosted within the claystone beds and concentrated within Injana Formation, whereas the Dibdibba Formation seems to form the roof of the caves. The mechanism of building caves starts by microdissolution forming microfractures. Then with time, they have developed to be vertical joints. These joints were gradually enlarged as a result of claystone exfoliation along joint planes. Chemical weathering, physical weathering, and sedimentary structure (mud balls) play a key role in the processes of cave evolution. Some caves appear to be irregular, but others tend to be regular with rectangular shape, enough for hosting human beings. These caves may have been used as homes for the ancient human for his protection and improvement of his life. At the same time as the caves were formed, there were other natural factors working continuously that destroy the cave. These factors are dissolution, soil creep, and mass sliding. This work highly recommends for further contributions in terms of the archaeological investigation on these caves to discover the ancient civilization in this area, if any.

Formation of zirconium molybdate sludge from an irradiated fuel and its dissolution into mixture of nitric acid and hydrogen peroxide

In the dissolution step of the PUREX process, a sludge of zirconium molybdate can be generated from zirconium and molybdenum dissolved in the solution. In order to avoid accumulation of sludge, a new cleaning method using a mixture of nitric acid and hydrogen peroxide was developed. In this work, the cleaning method was verified using an irradiated fuel. Cubic crystals of the zirconium molybdate ZrMo 2O 7(OH) 2 were formed upon dissolution of an irradiated PWR fuel. The sludge deposition continued after the completion of the fuel dissolution. A small amount of fissile material was incorporated into the sludge. Although almost the same amount of insoluble residue was present, the sludge could be dissolved with a HNO 3–H 2O 2 solution at 80 °C within 5 h. The sludge formation on the clean Zr surface is inhibited.

Spectroscopy of Hydrothermal Reactions 21. Decomposition Reactions and Kinetics of Ni(CO)4, Co(CO)4- and (η5-C5H5)Co(CO)2 in High Temperature Water

The decomposition behavior of aqueous Ni(CO)4, NaCo(CO)4, and (η5-C5H5)Co(CO)2 was studied by infrared spectroscopy using a titanium flow reactor with sapphire windows. A pressure of 275 bar was applied to prevent gas−liquid phase separation. Ni(CO)4 was investigated in the 50−270 °C temperature range with selected partial pressures of CO in the range of 0−60 bar. Without added CO, the Arrhenius parameters were Ea = 10.4 ± 1.3 kcal/mol and ln(A, s-l) = 10.4 ± 1.9 in the 50−90 °C range where a first-order rate law was followed. Complete decomposition took place at 170 °C within 23 s. The addition of excess CO raised the decomposition temperature. Aqueous Ni(CO)4 could be detected for at least 5 s at 270 °C with a 60 bar partial pressure of CO. The isoelectronic ion Co(CO)4- was found to be more stable than Ni(CO)4. Its decomposition was characterized in the 200−240 °C range without added CO. A first-order rate law was followed up to 50% decomposition, yielding Ea = 29.9 ± 3.7 kcal/mol and ln(A, s-1) = 25.9 ± 3.8. The greater robustness of Co(CO)4 compared to Ni(CO)4 is attributable to the strength of the metal−carbon bond. (η5-C5H5)Co(CO)2 decomposed in the 220−240 °C range to Co(CO)4- and a considerable amount of insoluble residue. Decomposition reactions for the three studied metal carbonyls were formulated.

Effects of solvent addition to acetylation medium on cellulose triacetate prepared from low-grade hardwood dissolving pulp

As cellulose triacetate was prepared from low-grade hardwood-dissolving pulp, a considerable amount of the insoluble residue was present in the acetylation medium of the acetic acid/acetic anhydride/sulfuric acid system, and it consisted mainly of cellulose triacetate (CTA) and xylan diacetate (XDA). As one of the remedies for reducing the insoluble residue, a solvent was added to the acetylation medium and the effects of the solvent addition on the amount of insoluble residue formed were studied. To do so, 17 different solvents were selected so as to cover a wide range of solubility parameters. The obtained results clearly indicated that the addition of the solvent affects the amount of insoluble residue and that, excluding dichloroacetic acid, nitromethane was effective for its reduction, but that neither methylene chloride nor nitroethane were in spite of their effectiveness for softwood-dissolving pulp, which would be due to the intrinsic properties of XDA on the solubility in the acetylation medium. A new acetylation system with such an appropriate solvent would, therefore, provide a clue as to an industrial usage of the low-grade hardwood-dissolving pulps for cellulose acetate production. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 69: 1445–1449, 1998

Effects of solvent addition to acetylation medium on cellulose triacetate prepared from low‐grade hardwood dissolving pulp

As cellulose triacetate was prepared from low-grade hardwood-dissolving pulp, a considerable amount of the insoluble residue was present in the acetylation medium of the acetic acid/acetic anhydride/sulfuric acid system, and it consisted mainly of cellulose triacetate (CTA) and xylan diacetate (XDA). As one of the remedies for reducing the insoluble residue, a solvent was added to the acetylation medium and the effects of the solvent addition on the amount of insoluble residue formed were studied. To do so, 17 different solvents were selected so as to cover a wide range of solubility parameters. The obtained results clearly indicated that the addition of the solvent affects the amount of insoluble residue and that, excluding dichloroacetic acid, nitromethane was effective for its reduction, but that neither methylene chloride nor nitroethane were in spite of their effectiveness for softwood-dissolving pulp, which would be due to the intrinsic properties of XDA on the solubility in the acetylation medium. A new acetylation system with such an appropriate solvent would, therefore, provide a clue as to an industrial usage of the low-grade hardwood-dissolving pulps for cellulose acetate production. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 69: 1445–1449, 1998

Effect of the insoluble residue content of starting powder on the properties of powder metallurgy steels

1. A study was made of the effects of insoluble residue content on the compressiblity and strength properties of specimens from iron and iron-1% graphite powders. It was established that changing the amount of insoluble residue in starting powder from 0.2 to 0.5% has no effect on compressibility and strength, but decreases the elongation of parts of medium density (6.4 g/cm3) by 25–30%. 2. Raising the amount of insoluble residue from 0.2 to 1.0% decreases the compressibility of iron powder by 2.5–3.5% and the strength of parts of high density (7 g/cm3) by 25–30%. Under these conditions, the elongation of iron powder specimens falls by a factor of 2.5–3 and that of specimens containing 0.8% of combined carbon by 20–30%. 3. The insoluble residue content of starting oxides should not exceed 0.2–0.3%. Iron powders manufactured by the reduction of iron oxides of higher insoluble residue contents are unsuitable for the production of parts of high density.

Pozzolanic Activity of Fly Ash

Various physico-chemical properties such as particle size distribution, specific gravity, specific surface area, chemical composition, solubility of Fly Ash (FA) in NaOH and pozzolanic activity of fly ash towards lime have been investigated. Chemical analysis of FAreveals that the FA used in this present investigation belongs to class F type of fly ash. XRD investigation of FA depicts the presence of crystalline mullite and quartz phases. Pozzolanic activity of fly ash was investigated by pH and electrical conductivity measurement, by determining the amount of calcium reacted with fly ash and by the amount of Insoluble Residue (IR) observed in FA-lime paste. XRD investigation of ash-lime paste identified the Calcium Silicate Hydrate (C-S-H) phase. The results obtained from these studies suggested that fly ash possesses pozzolanic activity. Key words: Pozzolanic activity; Fly ash (FA); Rice husk ash; Ordinary Portland Cement (OPC); Insoluble residue (IR); Calcium hydroxide (CH); Calcium silicate hydrate (C-S-H); Kinetics; XRD. DOI: 10.3329/bjsir.v45i4.7326 Bangladesh J. Sci. Ind. Res. 45(4), 303-308, 2010

The Glass Effect in Distillate Fuel Stability

Diesel fuels were stored in glass bottles at 54.4/sup 0/C (130/sup 0/F) or at 98.9/sup 0/C (210/sup 0/F). Some of the bottles were soft glass; some were borosilicate glass. Fuel degradation was measured by the change in light transmission and light scattering and by the amount of insoluble residue and soluble gum formed. Diesel fuel stored in borosilicate glass bottles deteriorated much more rapidly than the same fuel stored in soft glass bottles. Additional experiments showed that soft glass inhibited fuel degradation, while borosilicate glass was essentially inert toward the fuel. The effect of soft glass varied with the fuel. Soft glass greatly improved the stability of some fuels, but had almost no effect on other fuels. Therefore, storage of fuels in soft glass bottles could give misleading results in assessing the relative stabilities of distillate fuels.

Sedimentary Studies of the Wapsipinicon Formation in Iowa

ABSTRACT Detailed field study, including the collection of samples, was made of the Wapsipinicon formation and adjacent Silurian and Devonian beds in Iowa. The Wapsipinicon consists of about 100 feet of limestones, dolomites, and calcareous shales that are divided from the base upward into the Coggan, Otis, Kenwood, Spring Grove, and Davenport members. In the laboratory, the samples were digested in acid to determine the amount of insoluble residue, the mineralogy of the residue was studied with the aid of a petrographic microscope, and the ratio of calcite to dolomite in the samples was determined by means of stains. All three criteria (percentage of insoluble residue, mineralogy of insoluble residue, and calcite-dolomite ratio) were found to be of aid in correlation, but they are rarely conc usive evidence except when used together and in conjunction with field evidence.