Dilute Carbonate Research Articles

Changing the Linking Functionality in a Triblock Co-Polymer for Electrolyzer or Fuel Cell Membrane or Ionomer for Chemical Stability Improvements and Potentially Other Consequences.

We have developed a versatile scalable triblock polymer system for anion exchange membrane (AEM) based electrochemical energy conversion devices. This system is uniquely suited to solving both the membrane and ionomer challenges for the commercialization of AEM water electrolysis or fuel cells. Using our advanced fundamental understanding of AEMs based on our work which began in 2010, we can design systems from first principles to match the needs of the device. A triblock ABA polymer is readily fabricated that has both chemical and mechanical stability. The synthesis of these systems is robust, high yield and amenable to high volume production. It utilizes a novel dual chain transfer agent to mediate the chain-transfer ring-opening metathesis polymerization (ROMP) of cyclooctene (COE) or the polymerization of isoprene (IP) to give the hydrophobic B block of the polymer. This is followed by the reversible addition-fragmentation chain transfer radial polymerization of chloromethylstyrene (CMS). The polyCMS (pCMS) blocks are then quaternized with an amine to give the cationic hydrophilic A block. Before quaternization the B block is hydrogenated to give either semi-crystalline polyethylene (pE) or amorphous polymethylbutylene (pMB) from pCOE and pIP respectively. The obvious achilles heal in this system from a chemical durability standpoint is the linking ether functionality between the hydrophobic and hydrophilic blocks. The material we have synthesized to date have exceptional chemical and mechanical stability. It performs very well in ex-situ testing with KOH solutions and in device testing we have demonstrated >500 h at 50°C in water electrolysis in 5 cm2 cells in 1M carbonate electrolyte at 0.5 A cm-2. We attribute the chemical stability to the fact that we post quaternize the membrane to give methylpipiridinium cations and we assume that this reaction does not fully penetrate down the hydrophilic chain. This leaves a hydrophobic un-quaternized region close to the hydrophobic block that does not allow access to the ether linkage by the hydrated hydroxide anion. Recently a new approach to the telehelic mid block pCOE has been reported that has no ether linkages and allows the hydrophobic outer blocks to be linked by a methylene linker. This gives use an opportunity to directly contrast the chemical stability of two identical triblock co-polymers one with an ether linkage and one with a methylene linkage between blocks. In this presentation we will show the results from ex-situ chemical stability test one at low temperatures and higher hydroxide concentration and one at higher temperature and lower hydroxide concentration. There are many examples in polymer electrolyte chemistry where a simple change leads to unintended consequences. The geometry of the ether linkage versus the methylene linkage will change the way that the polymer chains will organize and entangle in ways that are not currently predictable. To probe the mechanical, chemical and morphological difference between these two polymers we will fully characterize and contrast both polymers physical chemical properties including water uptake, ionic conductivity, DSC, TGA, tensile strength and morphology through SAXS, WAXS and HRTEM. Data for the two polymer membranes will also be contrasted and compared in small laboratory 5 cm2 single cells for both electrolysis in dilute carbonate and H2/O2 fuel cells using conventional catalysts.

Sorption of U(VI) on dolomite in a dilute carbonate solution: behavior investigation and mechanism probe

Abstract The U(VI) sorption behavior on dolomite was systematically investigated in a dilute carbonate solution using batch technique. The distribution coefficients (K d) increased with the increasing time and temperature, but decreased with the increase of initial U(VI) concentration and ionic strength. As the initial pH increased from 2.0 to 10.5, the K d values first increased and then decreased, mainly due to the transition from electrostatic attraction to repulsion caused by the changes in U(VI) species. The sorption process was well-described by pseudo-second-order kinetic and Freundlich isotherm models, and was spontaneous, endothermic, heterogeneous, and pH-dependent. In the presence of HA/FA, at low pH, more HAs/FAs were adsorbed on dolomite surface, providing more sorption sites for the positively charged U(VI) species, and promoting the U(VI) sorption. At high pH, more HAs/FAs were dispersed in solution, encapsulating the negatively charged U(VI) species in aggregates, and inhibiting the U(VI) sorption. The promoting and inhibiting effects of HA on the sorption process are obviously stronger than FA. XPS spectra indicated that the surface ‒OH and CO3 2− on the hydroxylated dolomite and the –OH groups in HA/FA may be involved in U(VI) sorption. The results reported here provide valuable references for further understanding U(VI) migration in geological media.

Sources and mobility of carbonate melts beneath cratons, with implications for deep carbon cycling, metasomatism and rift initiation

Kimberlite and carbonatite magmas that intrude cratonic lithosphere are among the deepest probes of the terrestrial carbon cycle. Their co-existence on thick continental shields is commonly attributed to continuous partial melting sequences of carbonated peridotite at >150 km depths, possibly as deep as the mantle transition zone. At Tikiusaaq on the North Atlantic craton in West Greenland, approximately 160 Ma old ultrafresh kimberlite dykes and carbonatite sheets provide a rare opportunity to study the origin and evolution of carbonate-rich melts beneath cratons. Although their Sr–Nd–Hf–Pb–Li isotopic compositions suggest a common convecting upper mantle source that includes depleted and recycled oceanic crust components (e.g., negative ΔεHf coupled with >+5‰δ7Li), incompatible trace element modelling identifies only the kimberlites as near-primary low-degree partial melts (0.05–3%) of carbonated peridotite. In contrast, the trace element systematics of the carbonatites are difficult to reproduce by partial melting of carbonated peridotite, and the heavy carbon isotopic signatures (−3.6 to −2.4‰δ13C for carbonatites versus −5.7 to −3.6‰δ13C for kimberlites) require open-system fractionation at magmatic temperatures.Given that the oxidation state of Earth's mantle at >150 km depth is too reduced to enable larger volumes of ‘pure’ carbonate melt to migrate, it is reasonable to speculate that percolating near-solidus melts of carbonated peridotite must be silicate-dominated with only dilute carbonate contents, similar to the Tikiusaaq kimberlite compositions (e.g., 16–33 wt.% SiO2). This concept is supported by our findings from the North Atlantic craton where kimberlite and other deeply derived carbonated silicate melts, such as aillikites, exsolve their carbonate components within the shallow lithosphere en route to the Earth's surface, thereby producing carbonatite magmas. The relative abundances of trace elements of such highly differentiated ‘cratonic carbonatites’ have only little in common with those of metasomatic agents that act on the deeper lithosphere. Consequently, carbonatite trace element systematics should only be used with caution when constraining carbon mobility and metasomatism at mantle depths. Regardless of the exact nature of carbonate-bearing melts within the mantle lithosphere, they play an important role in enrichment processes, thereby decreasing the stability of buoyant cratons and promoting rift initiation – as exemplified by the Mesozoic–Cenozoic breakup of the North Atlantic craton.

Modeling Corrosion Reactions of Steel in a Dilute Carbonate Solution

This research models the corrosion reactions of a high-strength steel in an aerated, dilute, carbonate solution during a single-cycle voltammetry. Based on a previous study (Eliyan et al. in J Mater Eng Perform 24(6):1-8, 2015) and a literature survey, the corrosion reactions of the cathodic reduction, anodic dissolution, and passivation, as well as the interfacial interactions and the chemistry of the corrosion products are illustrated in schematics. The paper provides a visual guide on the corrosion reactions for steel in carbonate solutions based on the available mechanistic details that were reported and are still being investigated in literature.

Regularities of Rhenium and Uranium Sorption from Mixed Solutions with Weakly Basic Anion Exchange Resin

The results regarding uranium (U) and rhenium (Re) sorption from solutions containing both metals by AN-21 weakly basic anion exchange resin are presented in this article. The effects of the salt forms (sulphate, chloride, nitrate, hydroxide), the nature of the sulphate, nitrate, and chloride compounds (acids, sodium and zinc salts), and the carbonates at concentrations of 1 to 1000 mol/m3 were studied under static conditions. It was determined that rhenium from different solutions is well-sorbed by the salt forms and poorly sorbed by the hydrate forms. The nitrate and chloride compounds reduce rhenium sorption when their concentration is increased in contrast to the behaviour exhibited by the sulphate compounds. Uranium is well-sorbed by sulphate form of weakly basic anion exchange resin but only from sulphate solutions and dilute carbonate solutions. The different sorption characteristics of the metals were explained by considering their ionic states in the solutions.

Latest Oligocene–Late Miocene lacustrine systems of the north-central part of the Ebro Basin (Spain): sedimentary facies model and palaeogeographic synthesis

In the central part of the Ebro Basin (Spain), north of the Ebro River, three allostratigraphic or tectosedimentary units differentiated within the latest Oligocene–Late Miocene (upper Agenian–Vallesian) interval are sedimentologically characterized. These deposits represent carbonate and sulphate lacustrine environments fed by Pyrenean alluvial systems (Luna system and Huesca system). In each unit, several facies associations or lithofacies were mapped. These interfinger through time: gypsum lithofacies occupy the southernmost part of the study area and are surrounded by carbonate and/or detrital lithofacies to the north. Each lithofacies consists of different carbonate, sulphate and/or detrital facies, arranged in simple sequences, decimetres to metres thick. The four types of sequences characterized reflect a complex shallowing evolution involving carbonate or sulphate contexts. Thus, each lithofacies represents the sedimentation in a particular lacustrine or alluvial subenvironment. A single lacustrine system is proposed for the central part of the basin. Its evolution followed cycles of water level variations, which caused kilometre-scale migrations of the lake shoreline. In this model, two distinct situations or lakes alternated through time. (a) One represents high levels associated with a single body of dilute carbonate water, where massive carbonate facies formed influenced by organism proliferation. These lakes had wide palustrine vegetated margins, in which bioturbated facies developed. (b) The other represents low levels that correspond to a playa-lake model. Laminated sulphate deposits formed in the lake waters, while nodular gypsum originated in the surrounding saline mud flats and within the exposed, previously deposited carbonate sediments. Transitions from one situation to the other, including minor water level fluctuations within carbonate sedimentation conditions, were marked by the development of laminated and stromatolitic facies. Lake level variations were caused by climatic cycles and gave rise to the simple sequences and to the lithofacies lateral relationships recognized in this study. Correlation among tectosedimentary units in the studied Pyrenean domain and in the Iberian domain of the Ebro Basin shows that for units N1 and N2 the facies that resulted from dilute carbonate waters are rare in the lacustrine areas of the Iberian margin. This indicates that a strong hydrological contrast existed between both regions. On this basis, a theoretical asymmetrical facies model is proposed for the single lacustrine basin that extended over these regions.

The role of hydrogen in the process of stress corrosion cracking of pipeline steels in dilute carbonate-bicarbonate solution

Stress corrosion cracking (SCC) in buried highpressure pipelines occurs on the outside surface where ground water is in direct contact with pipelines through disruptions of the protective coating. Instances of SCC have been related to an electrolyte composed of alkaline carbonate–bicarbonate [1–3]. SCC of pipeline steels in high concentration of carbonate–bicarbonate solution (pH of about 10) has been well studied [4–7]. However, recent research [8] has shown that the chemistry of the solution beneath coating disbondments on pipelines is concerned with much lower carbonate– bicarbonate concentrations, and hence lower pH (about 7). SCC is transgranular in low-pH solution and is intergranular in high-pH solution [9–11]. Only a few studies have focused on the SCC of the pipeline steels in dilute carbonate–bicarbonate solutions in the presence of chloride ions. Since the low pH of solution facilitates hydrogen accumulation in stressed region in steel, hydrogen plays an important role in SCC [12]. It is important to clarify whether hydrogen could diffuse into the materials and its distribution status around the crack tip, if the dissolved hydrogen has influence on SCC of the pipeline in NS-4 solution. The research described in this paper was carried out with the following objectives: firstly to determine hydrogen reduction and enrichment near the crack tip, and secondly to investigate effects of hydrogen on the anodic SCC of the pipeline steels in dilute carbonate–bicarbonate solution. The materials used were pipeline X-80 and X-52 supplied by IPSCO, Canada. The nominal compositions are listed in Table I. Compact tension (CT) specimens were prepared from the pipeline steels and the dimensions are shown in Fig. 1. A sharp notch with a radius of 0.1 mm was made in the specimen along the longitudinal direction. All specimens were ground with up to 1000 grit emery paper before testing. The specimens were loaded by a wedge with thickness of 2.50 mm. The load was calibrated by a load–extension curve measured using a materials-testing system. NS-4 solution, the typical solution in coating disbondment area in Canadian pipelines [8], was used in this study to simulate coating disbonding condition on pipelines in the field. The composition of NS-4 solution is listed in Table II. The pH values of the solution were adjusted to 5 and 3 by adding H2SO4 to the solution to simulate the solution condition within the crack tip during SCC. Before measuring the hydrogen distribution in the steel, the specimens were immersed in NS-4 solutions of various pH for 72 h. Hydrogen pre-charging was conducted in 1 N H2SO4 ‡ 250 ppm As2O3 solution for 24 h. Measurements of hydrogen distribution were carried out using secondary-ion mass spectroscopy (SIMS). A primary ion beam of Ar, an accelerating voltage of 15 kV and a beam current of 1310y6 A were used. The spot diameter of the ion beam was

Macrocycle-Mediated Selective Transport of Plutonium(IV) Nitrate through Bulk Liquid and Supported Liquid Membranes Using Dicyclohexano-18-crown-6 as Mobile Carrier

Abstract Macrocycle-facilitated transport of Pu(IV) against its concentration gradient from aqueous nitric acid solutions across an organic bulk liquid membrane (BLM) and a thin-sheet supported liquid membrane (SLM) containing dicyclohexano-18-crown-6 as the mobile carrier and toluene as the membrane solvent was investigated. Extremely dilute and moderately concentrated plutonium nitrate solutions in about 3 mol/dm3 nitric acid generally constituted the source phase. Plutonium transport appreciably increased with stirring of both the source and recovery phases and also with the carrier concentration in the organic phase up to 0.3 mol/dm3 DC18C6 and then decreasing with higher concentrations of the carrier. Enhanced acidity of the aqueous source phase beyond 4 mol/dm3 HNO3 seriously affected the stripping of the cation. Among the several reagents tested, dilute sodium carbonate (0.5 mol/dm3) served efficiently as the strippant. Enka Accurel thin flat-sheet polypropylene (PP) films were used as the solid su...

Reactive dyes for cellulose. The reaction of alkoxychlorotriazinyl dyes with hydroxide ion

A Series of model alkoxychlorotriazinyl reactive dyes has been synthesised. Each compound, in turn, has been hydrolysed in dilute sodium carbonate solution and product ratios and rates of reaction determined. It has been found that the nature of the alkoxy group significantly influences the course and rate of the reaction.

Dilute, neutral pH standard of known conductivity and acid neutralizing capacity

By using the equilibrium computer program MINTEQA2, a quality control standard suitable for assessing measurement errors of pH, acid neutralizing capacity (ANC, formerly titration alkalinity) and conductivity of dilute, neutral pH solutions [ionic strength ≈ 4.6 × 10–4 mol kg–1 of solvent (water)] has been developed and tested. A dilute phosphate standard is prepared as a 200-fold dilution (by mass) of 0.025 mol kg–1(of solvent) KH2PO4 and Na2HPO4 standard buffer solution. At 25 °C and in equilibrium with 340 vppm (parts per million by volume) CO2, the standard has a theoretical pH of 6.89, a calculated ANC of 125 × 10–6 equiv kg–1(124.6 × 10–6 equiv dm–3) and a calculated conductivity of 37.6 × 10–4 S m–1. Theoretical pH and calculated ANC and conductivity values were also determined at equilibrium with laboratory CO2 concentrations ranging between 0 and 680 vppm. The dilute phosphate standard was measured repeatedly over a 6 month period at three laboratories. Measurements agreed well with the theoretical values (mean pH = 6.87, 2s=±0.100, n= 362; mean ANC = 124.5 × 10–6 equiv dm–3, 2s=±8.78, n= 294; mean conductivity = 37.7 × 10–4 S m–1 at 25 °C, 2s=±5.22, n= 308). The long-term systematic and random errors associated with the dilute phosphate standard are reduced for pH (because of reduced sensitivity to changes in CO2), and comparable for ANC and conductivity as compared to a dilute hydrogen carbonate standard (7.0 × 10–5 mol kg–1 NaHCO3 and 1.75 × 10–4 mol kg–1 KCl). For the dilute phosphate standard, among-day variation within a laboratory is the greatest source of error for ANC and conductivity measurements. For the dilute hydrogen carbonate standard, among-laboratory variation is the greatest source of error in pH measurements. Within-day variation is the greatest source of error in ANC measurements for the dilute hydrogen carbonate standard, while among-day variation within a laboratory is the greatest source of error for conductivity measurements of both dilute standards. Additional application of total speciation programs to the solving of design problems for quality control and assurance samples appears promising and justified.

Acid-Base Regulation in the Freshwater Pearl Mussel Margaritifera Margaritifera: Effects of Emersion and Low Water pH

ABSTRACT Freshwater pearl mussels Margaritifera margaritifera L. were exposed to air for 7 days, then immersed in circumneutral water (pH 7·85) or acidified water (pH 5·25) for 5 days. Mantle fluid pH and composition were monitored throughout. The mussels were observed to gape periodically when in air. Periodic gaping permitted aerial gas exchange such that mantle fluid and dissolved oxygen concentration stabilized at levels about twice and half, respectively, those of immersed mussels. During emersion, a dilute carbonate buffer equilibrium was established in the mantle fluid, involving reactions with CaCO3 reserves and, simultaneously, aerial release of CO2. Aerial CO2 release was sufficient to shift the carbonate buffer equilibrium in the alkaline direction, resulting in a significant alkalosis of mantle fluids during air exposure. Mantle fluid characteristics returned to initial (time zero) values within 3 days of immersion in circumneutral water (pH 7·85). When immersed in acid water (pH 5·25), the mussels were able to maintain a sizeable gradient between mantle fluid pH and ambient water pH. Regulation of mantle fluid pH in acid water did not involve any isolation reaction (valve closure), but rather environmental protons were buffered at the expense of CaCO3 reserves. Net calcium transfer, the difference between calcium uptake and loss, was shifted in the negative direction by decreases in water pH.

ChemInform Abstract: KINETIC MOLECULAR DESIGN OF URANOPHILE. LINEAR TRIS(DITHIOCARBAMATE) AS A STRONG AND RAPID EXTRACTING REAGENT FOR URANYL ION FROM DILUTE CARBONATE SOLUTION

Chemischer InformationsdienstVolume 16, Issue 45 Article ChemInform Abstract: KINETIC MOLECULAR DESIGN OF URANOPHILE. LINEAR TRIS(DITHIOCARBAMATE) AS A STRONG AND RAPID EXTRACTING REAGENT FOR URANYL ION FROM DILUTE CARBONATE SOLUTION I. TABUSHI, I. TABUSHISearch for more papers by this authorA. YOSHIZAWA, A. YOSHIZAWASearch for more papers by this authorH. MIZUNO, H. MIZUNOSearch for more papers by this author I. TABUSHI, I. TABUSHISearch for more papers by this authorA. YOSHIZAWA, A. YOSHIZAWASearch for more papers by this authorH. MIZUNO, H. MIZUNOSearch for more papers by this author First published: November 12, 1985 https://doi.org/10.1002/chin.198545057AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume16, Issue45November 12, 1985 RelatedInformation

Kinetic molecular design of uranophile. Linear tris(dithiocarbamate) as a strong and rapid extracting reagent for uranyl ion from dilute carbonate solution

Preparation au tri(acidedithiocarbamique)(4) dont on etudie la structure par RMN de 1 H et 13 C, IR, UV. Formation de complexes 1:1 avec l'ion uranyle en solution aqueuse. On compare les resultats avec ceux du macrocycle derivant de (4)

Depositional environments along a carbonate shelf to basin transect in the Silurian of Nevada, U.S.A.

During the Llandovery (Silurian) in central Nevada foundering of the shelf margin and drowning of a homoclinal carbonate ramp produced a rimmed carbonate shelf. Westward the shelf was bordered by a slope which passed into a deep-water basin. At the shelf margin, carbonate sand shoals (Lone Mountain Dolomite) aggraded and prograded westwards over the slope. The spatial and temporal facies variation in a transect across the slope (Roberts Mountains Formation) records the history of a prograding shelf margin.Initial slope sedimentation adjacent to the carbonate shelf margin was lime mudstone hemipelagically derived from the shelf. Westwards and downslope dilute carbonate turbidites and hemipelagic lime mudstone (laminated facies) were deposited. Contemporaneous slope-rise sediments (Fourmile Canyon Formation) consist primarily of siliciclastic mudstone with minor dilute carbonate turbidites and turbiditic siliciclastic siltstone, the latter essentially being part of the deep-water basin. Subsequent shelf margin progradation and increasing slope differentiation is reflected in the downslope introduction of calcarenite and conglomerate derived from the shelf margin. Slope sedimentation records an overall coarsening- and thickening-upwards cycle. Superimposed on this, in some areas, are small-scale coarsening- and thickening-upwards cycles reflecting deposition on carbonate debris aprons. Abandonment and subsequent build-out of the aprons reflects the pulsatory and uneven progradation of the outer shelf margin. Simultaneous with these depositional patterns, the immediate shelf margin periphery (top-of-slope) received hemipelagic lime mudstone sediments. Many rotational slides, some generating debris flows, indicate upper-slope instability. Most allochthonous carbonate debris from the shelf margin by-passed the top of slope and was deposited further downslope. With the westward progradation of the shelf margin the fringing facies migrated basinward.

Thermodynamic stability studies of the basic copper carbonate mineral, malachite

Natural malachite is a well defined solid demonstrating reproducible solubility behavior over a wide range of pH. The following equilibrium constants associated with the malachite dissolution equilibrium at 25°C, 1 atm were determined: K sp = a 2 cu 2+ a CO 3 2− K 2 w a 2 H+ = 3.5 ± 0.6 × 10 −34 (infinite dilution) K ∗ sp = [Cu 2+] 2[CO 2− 3]K 2 w a 2 H+ = 10. ± 0.2 × 10 −32 (0.72 ionic strength) K′ sp = m 2 Cu 2+ m COsu2− 3K 2 w a 2 H+ = 1.3 ± 0.1 × 10 −28 (36.9‰ salinity seawater). The temperature dependence of a “mixed” equilibrium constant, K sp +, of the form: K † sp = [Cu 2+] 2m CO 2− 3 K 2 w a 2 H+ has been measured at I = 0.72, yielding the relationship: log K † sp = (− 9.8 ± 0.03) × 10 4( 1 T°K ) + (1.52 ± 0.09) within a 5–25°C temperature range. The effect of pressure on the solubility of malachite in water and seawater was estimated from partial molar volume and compressibility data. For 25 °C at infinite dilution K' sp (1000 bar) K' sp(0) = 240 and in seawater K′ sp(1000) K' sp(0) = 44 . Comparison of stoichiometric and apparent malachite equilibrium constants has been used to estimate the extent of copper(II) ion interaction at the ionic strength of seawater. In dilute carbonate medium (total alkalinity, TA = 2.4 meq/kg H 2 O, pH 8.3), 2.9% of total dissolved copper exists as the free copper(II) ion and in seawater ( S = 36.9%., TA = 2.3 meq/kg H 2 O, pH = 8.1), [Cu 2+] T(Cu) is 3.1%. Total dissolved copper levels of approximately 450–750 nMol/Kg are necessary to attain malachite saturation conditions in the open ocean. Observations of malachite particles suspended in seawater must be explained by precipitation or solid phase substitution reactions from localized environments rather than by direct precipitation from bulk seawater.

Liquid Chromatography of Isomeric Phenols and Aromatic Acids Using a Poly (Ethyleneimine) Coated Silica Gel Micro-Column

Abstract Ortho-, meta- and para-isomers of various derivatives of phenols and aromatic acids have been separated on a cross-linked poly (ethyleneimine) coated silica gel micro-column liquid chromatography with very dilute carbonate or phosphate eluents.

Synthetic carbonaceous fuel and feedstock using nuclear power, air and water

Development of synthetic carbonaceous fuels and feedstocks (SCFF) is imperative if the U.S. is to maintain its world leadership. Nuclear power can provide not only the stationary thermal and electrical power backbone in the country but can also be of great assistance in supplying SCFF. All forms of carbonaceous materials can serve as sources of raw material for SCFF, however, here we consider the ultimate renewable resource of carbon which is CO 2 from the atmosphere or the oceans. A number of methods for the recovery of CO 2 have been examined. An absorption-stripping system utilizing dilute carbonate solvent appears most economical for atmospheric recovery while distillation appears of interest for sea-water recovery. An alternative isothermal process utilizing chlor-alkali cells is also described. Electrolytic hydrogen is thermocatalytically combined with the CO 2 to form methanol which can then be dehydrated to gasoline. Production cost is dominated by the energy for hydrogen and the plant capital investment. Base loaded nuclear power plants supplying peaking load and generating SCFF in an off-peak mode is proposed for reducing costs. Under 1974/5 conditions, incremental power costs would have been a minimum. Under 1985 escalated conditions, incremental costs indicate 6 mills/kWh(e) for power which yields 33.9 c/gallon methanol or 77.1 c/gallon of equivalent gasoline which takes credit for oxygen would break even with $23/bb1 of oil. The capital investment for producing the equivalent of one million barrels/day of gasoline in 142 nuclear reactors of 100 MW(e) capacity, operating in an off-peak mode, amounts to slightly more than the investment in new oil exploration and production facilities and considerable less than the projected outflow of capital to foreign OPEC countries. The nuclear synthesis-route using atmospheric and aquatic CO 2, simulates the solar photosynthetic process and provides a long-term renewable and environmentally acceptable alternate source of SCFF.

The Retention of Selected Radionuclides from Dilute Solutions by Panamanian Clays

stock solutions were prepared by adding aliquots of commercially prepared radioisotope chloride solutions to distilled water. Two separate stock solutions were prepared: one containing the ions Cs and Rb; the other, Sr and Ca. The aliquots of the radionuclide solutions used in preparing the stock solutions were chosen to provide approximately equal counting rates for each radiocation in the pair. The sodium-charged clays were suspended in a dilute sodium carbonate solution. The clay concentration of the suspensions was determined by drying overnight at 100 C and weighing a pipetted aliquot of the suspension in a tared evaporating dish. The sodium concentration of the suspension solution was determined by flame emission spectroscopy. Subsequently, a sodium dissolvedsolids correction was applied to the clay concentration of the suspension. The slurries were performed at room temperature using a magnetic mixer. The clay dosage was pipetted from the calibrated suspension into a plastic beaker containing 250 ml of stock solution. The su pensions were thoroughly shaken before pipetting, and the pipette was carefully inserted into a calibrated depth within the suspension to insure that a uniform clay sample was obtained with each dosage. After a contact time of 90 min, the slurries were vacuum filtered through a membrane filter of 0.22 p pore size. An aliquot of the filtrate was then taken and prepared for counting. Since the radiocation pairs 861Rb and '37Cs are both gamma-ray emitters, gamma spectroscopy was deemed to be the most practical method of counting this pair. A 5-ml sample of the slurry filtrate was diluted to 25 ml in a plastic container with distilled water. A drop of wetting agent added to this mixture insured that the bottom of the carton was covered in

Oxidation of Partially Etherified Cottons with Nitrogen Dioxide

Alkali-soluble, fibrous cellulosic textile materials may be prepared by the oxidation of partially etherified cottons with nitrogen dioxide. Modified cottons bearing ether substituents, such as aminoethyl, carboxymethyl, carboxyethyl, methyl, α-methylcarboxy methyl, or phosphonomethyl groups, were readily oxidized to yield products with high alkali solubility. Using milder oxidation conditions than are required with native or mercerized cottons, products were prepared that are almost completely soluble in dilute sodium hydroxide or sodium carbonate solutions. The oxidation may be carried out with gaseous nitrogen dioxide or with organic solvent solutions of nitrogen dioxide. Variables of the process and properties of the products were investigated most ex tensively with partially carboxymethylated cotton.

EFFECTIVENESS OF HEME IN THE AUGMENTATION OF GONADOTROPIC EXTRACTS FROM DIFFERENT SOURCES1

SEVERAL REPORTS have been made which show the increased effectiveness of gonadotropic hormones of the anterior pituitary gland when injected with other substances which are inactive as regards the stimulation of the ovary of ths immature rat. These augmenters include tannic acid (1), copper (2), and zinc salts (3, 4, 5), yeast extract and ash from yeast (a), male urine (6), blood serum (7), leuco cytes (8), egg albumin (9), merthiolate (10) and chlorophyll (11, 12). Casida (13) reported that the formed elements of blood augment gonadotropic extracts of sheep pituitary powder and that the ash from the formed elements does not. McShan and Meyer (14) separated the hemoglobin from the blood of the cow into heme and globin, and found that the hemin was an effective augmenter when it was dissolved in dilute sodium carbonate or sodium hydroxide solution and mixed in vitro with gonadotropic extract of sheep pituitary powder.