Kenneth E. Daugherty

A review of limestone additions to Portland cement and concrete

Abstract Whether or not to add limestone to Portland cement clinker and gypsum is currently being debated in many countries. Upon addition of the calcium carbonate a reaction occurs between it and the tricalcium aluminate that is present in the clinker to form calcium carboaluminates. Their ability to control set characteristics of the cement and their effects upon physical properties are discussed. It appears that in cements with higher levels of the tricalcium aluminate, positive or no effects on cement quality are noted. In cements with lower amounts of tricalcium aluminate, deleterious effects upon physical properties have been noted in some instances. It may be possible to control other properties of the cement to allow limestone additions even in cements with lower levels of tricalcium aluminate.

Analysis of lipids by one-dimensional thin-layer chromatography

A high-efficiency silica gel, (type HLF) thin-layer chromatography plate (HETLC), linear high-performance thin-layer chromatography plate (HPTLC) and densitometry method has been devised in order to resolve the major lipid classes obtained from rat brain tissues. This methodology, which has largely overcome prior problems, enhances the opportunity for assessing the glycerophospholipid and glycolipid compositions of tissues. DEAE-Sephadex column chromatography was used to separate the crude lipids extract into neutral and acidic lipid fractions. The lipid fractions were then spotted on separate HPTLC and HETLC plates and chromatographed in one dimension using one solvent system. Quantitation was by in situ densitometry with the absolute quantity of the lipid classes determined from co-chromatographed standards. Sensitivity was increased by using cupric sulfate reagent, which was found to be more sensitive than the conventional cupric acetate reagent. This method is applicable to a broader separation of lipid classes and has improved sensitivity.

Catalytic effect of alkali carbonates on the calcination of calcium carbonate

Abstract Alkali carbonates (except for francium carbonate) have been tested to enhance the calcination of calcium carbonate using a Lindberg furnace and a differential thermal analysis/thermogravimetric analysis (DTA-TGA) system. The alkali carbonates were mixed with calcium carbonate (calcite) at a weight ratio of 1:20 and were studied at constant temperatures of 800 and 700 °C in a Lindberg furnace and a DTA-TGA analyzer, respectively. The results of calcination rates (wt% h−1) from the Lindberg furnace and DTA-TGA analyzer have shown similarly that lithium carbonate is the best catalyst among the alkali carbonates.

Simultaneous analysis of carbon oxides and hydrocarbons by gas chromatography-mass spectrometry

The simultaneous determination of carbon monoxide, carbon oxide, and C1C4 hydrocarbons is demonstrated by gas chromatography-mass spect

Inhibition of the calcination of calcium carbonate

Abstract Aluminum oxide (Al 2 O 3 ), calcium oxide (CaO), vanadium pentoxide (V 2 O 5 ), and fly ash were respectively mixed with calcium carbonate (calcite, CaCO 3 ) in a ratio of 1:20 (w/w) and the mixtures were studied at a constant temperature of 700 ° C in a DTA-TGA analyzer. The results of calcination rate (wt% h −1 ) have shown that (Al 2 O 3 ) and CaO do not have any effect on the calcination rate of CaCO 3 , while V 2 O 5 and fly ash inhibit the calcination rate of CaCO 3 . An explanation is proposed.

Nondestructive adhesive analysis on stamps by Fourier transform infrared spectroscopy

Spectroscopy has long been a popular subject with respect to postal stamps, but analysis of postal stamps has been the subject of only a few spectroscopic studies. Fourier transform infrared techniques were used in developing a nondestructive technique to analyze the adhesives on the back of stamps. This factor is of importance since the value of a stamp is partially dependent on the conditions of the original adhesive. Diffuse reflectance was finally settled on as the method of choice for this analysis, and it shows great promise not only for stamp analysis but also for other types of documentation analysis as well.

Lithium carbonate enhancement of the calcination of calcium carbonate: proposed extended-shell model

Abstract Lithium carbonate (Li 2 CO 3 ) has been tested as a possible catalyst to enhance the calcination of calcium carbonate (CaCO 3 ) using a Lindberg furnace and a differential thermal analysis-thermogravimetric analysis (DTA-TGA) system. The Li 2 CO 3 was mixed with CaCO 3 (calcite) in weight ratios ranging from 1:500 to 1:20 and the mixtures were studied at constant temperatures of 800 and 700 °C in a Lindberg furnace and using a DTA-TGA analyzer. The results of the calcination rates (wt.% h −1 ) both from the Lindberg furnace and from the DTA-TGA analyzer have shown that the (Li 2 CO 3 ) -CaCO 3 mixture of about 1:200 has the highest calcination rate. In order to explain the data, a physical model is proposed. This extended-shell model has been tested with 5% magnesium chloride-calcium carbonate (MgCl 2 -CaCO 3 ) and 5% calcium chloride-calcium carbonate (CaCl 2 -CaCO 3 ) samples.

Analysis of carbon monoxide by molecular sieve trapping

Abstract The determination of carbon monoxide is demonstrated trapping CO on preconditioned molecular sieve and thermal desorption. Analysis in this case is performed by gas chromatography-mass spectrometry, although the trapping technique is applicable to other suitable GC techniques. Storage of the trapped sample for an indefinite time is possible with no degradation, even at several tenths of mg m −3 . Detection limits of 100 μg m −3 are reported with a linear dynamic range that permits analysis in the mg m −3 range. Balance gas interferences are reduced, but not eliminated.

Nuclear Magnetic Resonance Study of the Hydrolysis of Diethyl Methylphosphonite

The products of the hydrolysis reactions of diethyl methylphosphonite at room temperature have been elucidated by means of proton nuclear magnetic resonance. The reaction was followed by observing the methyl-hydrogen resonance, phosphorus-hydrogen resonance, methylenehydrogen resonance, and hydroxyl-hydrogen resonance. Upon addition of up to one mole of water per mole of diethyl methylphosphonite, ethyl hydrogen methylphosphinate was produced in a very rapid and complete reaction. Upon addition of greater than one mole of water—up to two moles of water per mole of diethyl methylphosphonite—the ethyl hydrogen methylphosphinate that was produced was further hydrolyzed to dihydrogen methylphosphinate in a very slow reaction. At ratios of two or more moles of water per mole of diethyl methylphosphonite, only dihydrogen methylphosphinate and ethanol were observed in solution after the reactions had come to completion. Trivalent phosphorus hydrolysis products were not observed in this reaction sequence. The chemical shifts, spin—spin coupling constants, and analytical data are described.

Some Physical Characteristics and Heavy Metal Analyses of Cotton Gin Waste for Potential Use as an Alternative Fuel

The use of cotton gin waste as a fuel is an attractive solution to the problems of disposing of a surplus agricultural waste as well as supplementing energy resources. Because a qualified alternative fuel must meet both environmental emission standards and industrial fuel standards, the physical characteristics of cotton gin waste and its toxic element concentrations are important for its initial objective evaluation as a fuel. Constituent components, moisture contents, and ash contents of four separate parts of cotton gin waste were determined and evaluated, closely following the American Society for Testing and Materials (ASTM) test methods. The three most toxic heavy metals, arsenic (As), chromium (Cr), and lead (Pb), chosen for quantitative analyses were also determined by using an inductively coupled plasma atomic emission spectrometry and a microwave oven sample digestion method. This study revealed that the lint component is the leading candidate for fuel, which closely meets both environmental emission and industrial fuel standards.