Low Chlorides Research Articles

Electrochemical corrosion and high temperature hot corrosion behavior of NbTaTiV and CrNbTaTiV high entropy alloy

NbTaTiV and CrNbTaTiV were fabricated by arc melting and effect of Cr element on electrochemical and high temperature hot corrosion behavior were compared. Electrochemical corrosion investigations revealed that Laves phase at grain boundaries of CrNbTaTiV would underwent galvanic corrosion, resulting in a marginal reduction in corrosion resistance. The results of high temperature hot corrosion showed that within Na2SO4 + 25 wt% NaCl molten salt environment, the oxide film formed by Cr element effectively improved the surface stability, reduced the formation of unprotected loose corrosion products and the generation of low melting point chlorides with strong volatility, which improved the resistance of molten salt corrosion.

Active Pd intermediates of the Suzuki-Miyaura reaction with low reactive aryl chlorides under “ligand-free” conditions

Despite extensive studies regarding Pd intermediates reacting in the transmetalation step of the Suzuki–Miyaura reaction (SMR), direct evidence obtained under real turnover conditions supporting the widely accepted assumptions regarding the activity of Pd hydroxo complexes is lacking. Herein, results concerning the major reactivity of Pd-OH- and/or Pd-OR-containing complexes (RO− is the base anion) in the transmetalation step with arylboronic acid under “ligand-free” turnover conditions are presented. By contrast, aryl chloride activation was mainly realized through halide-containing Pd complexes. Data regarding the catalytic involvement of particular Pd species were obtained under real catalytic conditions by measuring differential selectivity of the competing reactions. In the reaction with demanding aryl chlorides catalyzed by “ligand-free” catalytic systems that is optimal from the viewpoints of environment, cost, and availability, the composition of active Pd complexes in the transmetalation step was similar to that for the reaction using more reactive aryl bromides and iodides.

Direct electrochemical reduction of low titanium chlorides into titanium aluminide alloy powders from molten eutectic KCl–LiCl–MgCl2

Titanium aluminides (Ti–Al) alloys are useful high-temperature structural materials for many industrial applications, but still limited by the long-cycle production and high-cost. In this study, a novel preparation process of Ti–Al alloys from low titanium chlorides (LTC) by electrochemical reduction was investigated. Cyclic voltammetry and square wave voltammetry were employed to evaluate the electrochemical behaviors of LTC in KCl–LiCl–MgCl2 melts. The data suggested that the reduction process of LTC at the cathode occurred through step by step: Ti3+→Ti2+, Al3+→Al, Ti2+/Al3+→Ti–Al alloy, and Ti2+→Ti. Inductively coupled plasma atomic emission spectrometry was utilized to determine the changes in Ti and Al ion concentrations during electrolysis of the melts on different anode materials. Using graphite anode, the data revealed a rapid decrease in both Ti and Al ions contents in the melts as the electrolysis time was prolonged. By comparison, the electrolysis system remained relatively stable using aluminum anode. The cathodic products using both graphite and aluminum anodes were then characterized by X-ray diffraction, scanning electron microscopy, and energy dispersive spectrometry. As Al ion content declined in the melts using graphite rod anode, the cathodic products transformed from AlTi3 to Ti metal. By comparison, stable Al0.64Ti0.36 and AlTi3 were obtained when an aluminum rod was used as anode.

How to find high-quality petroleum source rocks in saline lacustrine basins: A case study from the Cenozoic Qaidam Basin, NW China

Despite having made significant contributions to global hydrocarbon occurrences, source rocks in saline lacustrine basins show great mineralogical and organic geochemical heterogeneity and the controlling mechanism is weakly studied. Here, we use the Cenozoic Qaidam Basin as an example to compare the organic and inorganic parameters of fine-grained sediments in different lacustrine facies and to figure out the characterization and distribution of effective petroleum source rocks in saline lacustrine systems. Organic-inorganic database of six selected boreholes show that in the bench-margin (high-gradient) lacustrine system, fine-grained sediments in sublittoral brackish-mesosaline zones containing low chlorides (<2000 ppm) and high carbonates (25–50%) show low total organic carbon (TOC) contents (0.4–1.0%) and high chloroform extracts (0.05–0.2%); centripetally sediments in penesaline profundal zones averagely have higher chlorides (2000–15000 ppm), lower carbonates (15–35%), higher TOC contents (0.6–1.2%), and higher extracts (0.05–0.3%). These two facies can both develop valid petroleum source rocks. In the ramp-margin (low-gradient) lacustrine system, dark fine-grained sediments in penesaline centers with low carbonate (15–25%) and high chloride contents (2000–15000 ppm) show high TOC contents (0.8–2.0%) but extremely low hydrogen indexes (<100 mg HC/g TOC) (little extracts), only developing as valid gas/or biogas source rocks. Supersaline fine-grained sediments in both lacustrine systems develop invalid source rocks. Lateral superimposition maps show that fine-grained sediments with high hydrocarbon generation potential generally contain averagely 25–50% carbonates. Therefore, brackish-penesaline water salinity and bench-type basement are two necessary conditions to develop high-quality petroleum source rocks in saline lacustrine systems and average carbonate content can be a general good mineralogical indicator.

REVIEW ON ENHANCING TECHNOLOGIES OF HEAT TRANSFER THROUGH PHASE CHANGE MATERIALS

This review concentrates deeply on the recent studies performed on the phase change materials (PCMs) in order to enhance their performance. Most of these enhancing techniques fall in the following areas of interest (i) Development of new PCMs with promising thermo-physical properties. The researches recommend some promising substances to be used as a PCM such as pure inorganic salts (low cost chlorides, nitrates and carbonates), salt eutectics (KNO3–LiNO3 and KNO3–NaNO3–LiNO3), liquid metals (Gallium), esters, nanofluids (Al2O3/water, CuO/water and alumina-water), and polyols (sugar alcohol like polyethelene glycol, erythritol and xylitol). (ii) Introducing of composite mixtures to exaggerate the benefits of used materials. Composites could be obtained by mixing PCMs like fatty acid esters with building materials like concrete pavements, cement or gypsum or with isolating materials like perlite to keep satisfying room temperature for long time. PCMs could be mixed or be used in cascaded configuration layered and ordered according to their melting temperature. Good conducting materials like graphite and aluminum were introduced to be mixed with PCMs to enhance the thermal conductivity of PCM. Stable materials like Diatomite and silica were introduced to enhance the stability of the PCM to retain its properties for a lot of melting/freezing cycles. Also, nano particles of TiO2, ZnO, CuO, and Silver-Titania, are added to generally enhance the PCM thermo-physical properties. (iii) Configuration of PCM container to achieve higher heat transfer rates by changing the aspect ratio or by adding fins. The studies focused on adding internal fins, external fins, and increasing the aspect ratio of the PCM vertical container to induce natural convection. Experiments advise to focus on increasing the number and height of fins more than focusing of fins thickness. (iv) Encapsulation technology of PCM to provide the largest heat transfer surface and avoid leakage when in liquid state as well as allowing larger surface area for heat transfer and protection in handling hazardous materials. It was observed that the core-to-coating ratio plays an important role in deciding the thermal and structural stability of the encapsulated PCM. An increased core-to-coating ratio results in a weak encapsulation, whereas, the amount of PCM and hence the heat storage capacity decreases with a decreased core-to-coating ratio. Among all the microencapsulation methods, the most common methods described in the literature for the production of microencapsulated phase change materials (MEPCMs) are interfacial polymerization, suspension polymerization, coacervation, emulsion polymerization, and spray drying.

Electrodeposition of Iron and Iron-Based Alloys from Ethylene Glycol Non-Aqueous Solutions

Iron and iron-alloys electrodeposition is considered a promising way for the fabrication of ferromagnetic thin films with tuned magnetic properties, especially for microfabrication industry [1]. Moreover, the use of iron as main component in magnets can reduce the material cost and toxicity. Film quality is highly dependent on contaminations, such as oxygen. Avoiding light-elements contaminations is nontrivial in the case of water-based solutions because of the formation of oxides/hydroxides at the working electrode due to local pH dependence, leading to poor magnetic performances. Thus, organic systems may represent a good alternative to traditional baths. Non-aqueous solutions based on ethylene glycol have been already reported for electrodeposition of iron [2], where the low chlorides content led to a compact and pure films. Several other approaches, based on DESs and Ionic Liquids, are present in literature [3], [4]. The low coercivity of ≈20 Oe showed in the previous work can thus be tailored with the addition of other metals or non-metals as alloying elements. This kind of materials are commonly obtained by metallurgy or sintering, with the strong limitations in terms of thickness and device integration. Iron co-deposition were investigated by means of the traditional electrochemical characterization, cyclic voltammetry (CV) and linear sweep voltammetry (LSV), and with more practical tools such as Hull cell. The films were deposited by means of potentiostatic and galvanostatic depositions, showing the dependence between experimental conditions and film composition (XRF). Results in in terms of morphology (SEM), composition/purity (EDX), microstructure (XRD) and magnetic properties (VSM) are shown. [1] B. Y. Yoo, S. C. Hernandez, D. Y. Park, and N. V. Myung, “Electrodeposition of FeCoNi thin films for magnetic-MEMS devices,” Electrochim. Acta, vol. 51, no. 28, pp. 6346–6352, 2006. [2] G. Panzeri, A. Accogli, E. Gibertini, C. Rinaldi, L. Nobili, and L. Magagnin, “Electrodeposition of high-purity nanostructured iron films from Fe(II) and Fe(III) non-aqueous solutions based on ethylene glycol,” Electrochim. Acta, no. Ii, 2018. [3] A. P. Abbott and K. J. McKenzie, “Application of ionic liquids to the electrodeposition of metals,” Phys. Chem. Chem. Phys., vol. 8, no. 37, p. 4265, 2006. [4] T. Welton, “Room-Temperature Ionic Liquids. Solvents for Synthesis and Catalysis,” Chem. Rev., vol. 99, no. 8, pp. 2071–2084, 1999.

Review on Enhancing Technologies of Heat Transfer through Phase Change Materials

This review concentrates deeply on the studies performed in the ongoing decade. Most recent researches on PCM focus on how to add enhancing techniques to exaggerate its performance. Most of these enhancing techniques fall in the following areas of interest (i) Study new PCMs with promising thermo-physical properties. The studies recommended some promising substances to be used as a PCM, these substances include pure inorganic salts (low cost chlorides, nitrates and carbonates), salt eutectics (KNO3–LiNO3 and KNO3–NaNO3–LiNO3), liquid metals (Gallium) and metallic eutectic alloys, esters, and nanofluids (Al2O3/water, CuO/water and alumina-water), and polyols (sugar alcohol like polyethelene glycol, erythritol and xylitol). (ii) Introducing composite mixtures to exaggerate the benefits of used materials. Composites could be by mixing PCMs like fatty acid esters with building materials like concrete pavements, cement or gypsum or with isolating materials like perlite to keep satisfying room temperature for long time. PCMs could be mixed or be used in cascaded configuration layered and ordered according to their melting temperature. Good conducting materials like graphite and aluminum were introduced to be mixed with PCMs to enhance the thermal conductivity of PCM. Stable materials like Diatomite and silica were introduced to enhance the stability of the PCM to retain its properties for a lot of melting/freezing cycles. Also, nano particles of TiO2, ZnO, CuO, and Silver-Titania, are added to generally enhance the PCM thermo-physical properties. (iii) Configuration of PCM container to achieve higher heat transfer rates by changing the aspect ratio or by adding fins. The studies focused on adding internal fins, external fins, and increasing the aspect ratio of the PCM vertical container to induce natural convection. Experiments advise to focus on increasing the number and height of fins more than focusing of fins thickness. (iv) Encapsulation technology of PCM to provide the largest heat transfer surface and avoid leakage when in liquid state state as well as allowing larger surface area for heat transfer and protection in handling hazardous materials. . It was observed that the core-to-coating ratio plays an important role in deciding the thermal and structural stability of the encapsulated PCM. An increased core-to-coating ratio results in a weak encapsulation, whereas, the amount of PCM and hence the heat storage capacity decreases with a decreased core-to-coating ratio. Among all the microencapsulation methods, the most common methods described in the literature for the production of microencapsulated phase change materials (MEPCMs) are interfacial polymerization, suspension polymerization coacervation, emulsion polymerization, and spray drying.

Synthesis of inorganic aerogels via rapid gelation using chloride precursors

This paper describes the synthesis of silica, titania, zirconia and mixed-metal-oxide aerogels by a new facile approach. The corresponding low cost and non-toxic chlorides instead of the well established but more expensive and deleterious alkoxy precursors were used as starting materials. Hydrolysis of the precursors led to wet gels. The strong exothermic reaction in the case of TiCl4 or SiCl4 as a gel precursor can be controlled by both cooling and immersing the needle of the syringe in the aqueous solution. Under optimal conditions a rapid formation of silica- and zirconia based hydrogels could be achieved even without additional amounts of an auxiliary agent. It is shown that in all other cases the hydrolysis reaction and gel formation can be controlled by adding agents with crosslinking properties like propylene oxide, dilution with alcohols or starting from water glass. Water glass not only has the function of a cheap network former but also allows the strict adjustment of the pH value via neutralization of the acid forming hydrolysis reactions. Supercritical drying of the wet alkogel in CO2 delivered aerogels with BET surfaces up to 1390 m2 g−1, as determined by nitrogen adsorption measurements. In addition, the characterization includes XRD and SEM. These findings provide new physical insights into the hydrolysis of the gel precursors and lead to a significant reduction in production costs of inorganic aerogels.

Promoting H2 generation from the reaction of Mg nanoparticles and water using cations

H2 generation from the reaction between Mg nanoparticles and water can be significantly promoted by low cost chlorides. The promotion effect exhibits strong correlation with the OH(-) affinity of the corresponding cation. This interesting observation offers a simple and effective solution to portable H2 generation under mild conditions.

Regeneration of Bleaching Clay Waste by Chemical Activation with Chloride Salts

Spent bleaching earth (SBE) was regenerated by chemical activation with low cost and low pollution chlorides as activating agents. Under the conditions of activation temperature of 600°C and holding time of 1 h investigated, results show that fresh bleaching earth and regenerated bleaching earth are type IV with hysteresis loops corresponding to type H3 from nitrogen adsorption–desorption isotherms, indicating slit-shaped mesoporous structure. It is also found that the effect of the regeneration treatment studied in the present work on the pore structures and chemical properties of the resulting solids is negligible compared to the fresh bleaching earth. On the other hand, the pore properties of these chemically activated solids are higher than those of the sample regenerated from heat regeneration, but only approximate 45% of surface area are reclaimed. It implies that the carbon residues could be retained within pores and/or clogs the entrance of pores, resulting in a decrease in pore properties.

Effect of polymer characteristics on Beckmann rearrangement of polymer supported ketoximes

AbstractBeckmann rearrangement has been carried out in polymeric oximes synthesised from rigid styrene–divinylbenzene copolymer and flexible styrene–hexanediol diacrylate (HDODA) copolymer. Oxime functions were incorporated into these polymers through a series of polymer‐analogous reactions. First the polymers were subjected to Friedel‐Crafts acylation reactions with low molecular weight acid chlorides to give a set of polymeric ketones. These polymeric ketones were converted to oximes by treating with hydroxylamine hydrochloride in the presence of pyridine. The oximes were subjected to rearrangement under acidic conditions into substituted amides. The polymeric amides obtained were characterised by IR spectroscopy and chemical degradative analysis. The rearrangement in the macromolecular matrices were found to follow the same mechanistic path as in the low molecular weight analogues. The rate of rearrangement was found to be faster in the HDODA crosslinked polystyrene system.© 2002 Society of Chemical Industry

Some Methods for Assessing the Quality of Striped Bass for Use in Laboratory Studies

Abstract Techniques are described for assessing the quality of cultured striped bass (Morone saxatilis) for use in laboratory studies. Larval striped bass can be screened for swim bladder inflation by their responses to anesthesia with tricaine (MS-222) or benzocaine. Typical values for blood chemistry, condition factor, and responses to a saltwater challenge were established for normal fish larger than 90 mm. Neither blood chemistry measurements, nor liver anatomy, nor body cavity fat correlated well with the incidence of uninflated swim bladders. Extremely low plasma chlorides were found in some fish without inflated swim bladders. Blood characteristics of normal fish fell within reported ranges for hematocrit and total plasma proteins.

Impact of paper mill effluents on the distribution of cyanobacteria in the River Godavari, India

The impact of paper mill effluents on the distribution of Cyanobacteria in the River Godavari has been studied for a period of 2 years. The river water before the entry of effluents showed high pH, dissolved oxygen, carbonates and low organic matter, hardness, chlorides, bicarbonates, nitrates, phosphates, and silicates. At the entry of effluents, there is considerable decline in dissolved oxygen content and increase in other factors. After 1 km from the point of discharge of wastes quantitatively most of factors are in between the two earlier stations. Cyanobacteria are found to constitute 30% and 67.8% by numerical abundance at unpolluted and highly polluted stations respectively. Multiple Regression Analysis has been employed and certain mathematical models were derived to draw specific relationships between the distribution of Cyanobacteria and physico-chemical factors.

Efficient N-Alkylation of Pyrrole Under Solid Triphase Transfer Catalysis Conditions. Application to N-Oxyalkyl Pyrroles

Abstract Synthesis of N-substituted pyrroles was easily performed on a large scale under solid triphase transfer catalysis conditions. This method allows to use low reactive alkyl chlorides as the alkylating agents. Small polyethyleneglycol chlorides can also be used as the substituents and yield N-oxyalkyl pyrroles.

Chemically assisted ion beam etching of GaAs, Ti, and Mo

Investigations with argon and chlorinated ion beams have shown that the etch rates of GaAs and Ti are strongly dependent on the flux of molecular and atomic chlorine. Etch rate increases were observed with an increase in the chlorine flux from the background gas composition or from the impinging ion beam. At increased chlorine concentrations in the presence of ion bombardment, wall profiles were altered from an overcut slope to nearly vertical. In the etching of Mo, etch rates were limited by the removal of low volatility chlorides by ion-assisted mechanisms.

The homogeneous polymerization of phenylacetylene over MoCl 5

The kinetics of the homogeneous polymerization of phenylacetylene catalyzed by a benzene solution of MoCl 5 have been investigated. The k p = 6·5 l./mole · min at 70°C, the k PA 0 = 8·77 × 10 −2 l./mole · min, and the sum of the chain limiting and termination constants 2·7 × 10 −2 l./mole · min. The true activation energy was 8·0 ± 0·5 kcal/mole Gel-chromatography, IR and NMR spectroscopy, as well as the results of using radio-active stoppers have made it possible to state that the phenylacetylene (PA) polymerization has a mechanism of multiple centres, namely of co-ordination (PA with M ̄ n > 2000 ) and organo-metallic oligomers ( M ̄ n = 1000 –1500 ); they are produced by low valency molybdenum chlorides. The structure of the polymers synthesized in various conditions has been examined and the dependence of the latte on its molecular weight.

Recent Concerns with Reactor Coolant Chemistry Technology in Pressurized Water Reactors

Three concerns have recently arisen in reactor coolant chemistry technology: (a) the projected shortage of highly enriched, 99.99% 7Li for the control of reactor coolant pH, (b) the availability of anion resins for minimizing chloride elution problems, and (c) the additional inservice inspection requirements for the integrity of steam generator tubes, which subject plant personnel to radiation exposure. The normal consumption of 7Li can be reduced with modifications to plant operations, particularly those associated with purification demineralizers. The ion-exchange industry is having some difficulty in supplying the anion resins with low residual chlorides that are needed for the chloride elution problem, but they are actively working to provide them in the near future. Recognizing the importance of radiation levels associated with steam generator inservice inspection, Babcock & Wilcox is conducting a study program to determine the characteristics of corrosion products, to develop mathematical models that predict corrosion product behavior, and to develop methods for removing or minimizing the buildup of corrosion products in the reactor coolant system.

Osmolality of blood and intestinal contents in the pig, guinea pig, and Ascaris lumbricoides.

It is confirmed that the small intestine of the pig has contents which are hypertonic to both pig serum (I) and the hemolymph (II) of the parasite Ascaris lumbricoides. With starved pigs (in the abattoir) the following osmolalities were recorded: intestinal contents, 427; I, 340; II, 323; and one sample of ascaris faeces (III), 311 milliosmolal (mOsm). Samples from normally fed pigs, obtained within 10 minutes post-mortem, gave a mean value of 311 mOsm for I and the contents of the anterior section of the small intestine averaged 320 mOsm, but those of the middle section averaged 391 mOsm. I, obtained from the ears of normal pigs, was only 302 mOsm. The contents of guinea pig small intestine decreased from 326 mOsm to 292 mOsm with 24 hours starvation, but no changes were detected in guinea pig I and the average value was 297 mOsm. The osmotic gradient across the body wall of A. lumbricoides is reversed soon after the worms are removed from the pig, and this effect is delayed at a lower temperature. The reversed osmoregulation is assisted by the ejection of III hypotonic to the hemolymph. It is confirmed that the chloride rise in II is slow, but it is shown that the potassium drop occurs soon after the worms leave their host. There was a significant but small decrease in chlorides of II when the worms were in media containing low chlorides.

Tuberculous meningitis in children. (An analysis of 90 cases with special emphasis on some factors influencing the prognosis).

Ninety cases of tuberculous meningitis have been analysed with special reference to some prognostic factors such as the age of the patient, duration of symptoms before treatment, C.S.F. picture and type of treatment. 78·8 per cent. of cases were males and 84·4 per cent. below the age of 5 years. The peak incidence was below 3 years, 21·1 per cent. of cases occurring below the age of 1 year, the youngest patient being 4 months old. History of contact could be obtained in 27·78 per cent. of cases. X-Ray chest showed evidence of intrathoracic tuberculous foci in 74·4 per cent. of cases, with miliary lesions in 15·5 per cent., hilar lymphadenopathy in 33·3 per cent., bronchopneumonic infiltration in 21·1 per cent., fibrosis in 3·3 per cent. and thickened pleura in 1·1 per cent. of cases. Out of 90 cases, 35 expired, another 35 left the hospital in an unsatisfactory state, and only 20 cases recovered, giving a satisfactory response in 22·2 per cent. of cases. The combined figures for mortality and unsatisfactory results were 82·9 per cent., 77·2 per cent. and 64·3 per cent. between the age groups 0 to 2, 2 to 5 and above 5 years respectively. 84·2 per cent. of cases with coma and/or fits either proved fatal or had severe neurological sequelae. Low cerebrospinal fluid sugar and chlorides and raised proteins affected the prognosis adversely. Treatment under “Category I, II and III” showed satisfactory response in 29·3, 50 and 11·65 per cent. of cases respectively. Steroid therapy did not seem to favourably influence the results in cases picked up at random.

Chemical Factors Affecting Stress Corrosion Cracking of 18–8 Stainless Steels

Transgranular stress corrosion cracking of 18–8 Type 304 specimens in boiling 42% does not depend on rate of stressing (<1 sec to 10 min) nor on small variations in degree of plastic deformation. Cold worked specimens fail in shorter times than annealed, sheared specimens. Addition of to decreases cracking time whereas addition of increases the time. Pre‐exposure of unstressed specimens to slightly decreases cracking times of the same specimens subsequently stressed. Cracks occur along sheared edges of unstressed specimens despite stress relief anneal at 375°C for 2 hr.Cracks propagate along sheared edges of U‐bend specimens at 0.5 to 1 cm/hr through that portion of the specimen cross section in tension, the rate being much slower through the remaining cross section. No induction time for cracks to initiate was observed.Sizeable pits are not necessary for cracking in , but appear to be essential in media like which in absence of pitting is not particularly active in causing cracking. The pitting mechanism produces concentrated low pH metal chlorides within the pit, which like cause immediate cracking. Oxygen is required for pitting of 18–8 by solutions as shown by Uhlig and Morrill, and hence also for stress corrosion cracking as observed by Williams and Eckel, but oxygen is not necessary in or .Cracking can be prevented by cathodic protection at a CD. of 0.03 ma/cm2 or higher. Anodic CD. up to 0.01 ma/cm2 were found to have no effect on cracking tendency, nor did coupling of 18–8 to Pt.