Alkali Ratio Research Articles

Correction of the acid-alkaline state in patients with asthma

Background. The acid-alkaline state (AAS) in physiological conditions is caused by a certain ratio of acids and alkalis in blood plasma as well as in organs and tissues. Imbalances of the above ratio are observed in patients with asthma (As).
 Objective. To study AAS in patients with an uncontrolled course of As.
 Materials and methods. The study involved 27 patients having a moderately severe course of As with metabolic acidosis and without any controls. Physical examinations were made; respiratory function and AAS were assessed. The patients were divided into two groups: 13 cases – group 1 and 14 cases – group 2. Their basic treatment included budesonide / formoterol fumarate dehydrate 160/4.5 µg, with use of control questionnaires for As (ACQ-5) and life quality (SF-36). Additionally to their therapy patients from group 1 received 250 ml of 4.2 % sodium bicarbonate intravenously by drop infusions thrice daily every other day.
 Results and discussion. All the patients had a reduced control over As from 3.5 to 5 points (4 [3.5; 4.5] in group 1 and 4.5 [4; 5] in group 2). According to spirography data, the level of rate values before treatment in cases from group 1 was as follows: forced expiratory volume in 1 sec (FEV1) = 54.00 % [47.00; 59.00], peak expiratory flow (PEF) 25 % = 52.00 % [49.00; 57.00], PEF 50 % = 51.40 % [41.00; 57.00], PEF 75 % = 50.00 % [43.00; 57.10]. In patients from group 2 their level of rate values before treatment was as follows: FEV1 = 57.00 % [52.00; 61.00], PEF 25 % = 56.10 % [52.00; 59.70], PEF 50 % = 54.40 % [47.00; 59.00], PEF 75 % = 54.00 % [47.30; 60.10]. AAS values in cases from group 1 were: рН = 7.32±0.05, РСО2 = 33.8±1.34 mm Hg, ВЕ = -4,8±0,01 mmol/l; in patients from group 2 these were: рН = 7.31±0.04, РСО2 = 32.3±1.13 mm Hg, ВЕ = -4.25±0.01 mmol/l. After the treatment, the following changes were registered: respiratory function indices improved in both groups, but reliable changes versus pre-treatment results were revealed in 1st group – FEV1, PEF 25 % and PEF 75 % (p<0.05), while in 2nd group it was only in PEF 25 %. Both groups demonstrated positive changes of all AAS indices, but reliable changes in all examined indices were found out in patients from group 1 (р<0,05), whose treatment effectiveness was assessed as good in 8 cases and satisfactory in 4. In patients from group 2 the result of treatment was satisfactory in 9 cases, whereas in 5 patients it was unsatisfactory.
 Conclusions. Inclusion of sodium bicarbonate into combination therapy for patients with As is not accompanied with development of any adverse events and is recommended for using in combination therapy for exacerbations of As, particularly if metabolic acidosis develops.

Influence of brick industrial rice husk ash on properties of ambient cured geopolymer mortar matrix

Abstract Sustainability plays an important role by utilising hazardous waste into green technology. This study includes various Class F Fly Ash (CFFA) and Brick Industrial Rice Husk Ash (BIRHA) proportions with alkalis to make matrix of geopolymer mortar under the curing temperature of 40 °C ± 2 °C till the testing ages. The effect of BIRHA upto 50% with NaOH concentration of 10 M was assessed with sodium based alkali ratio of 2.5. Morphology and mineralogy was determined using FESEM, XRD and Wet chemical analysis for the base binders. Fresh mortar properties like flowability and unit weight was determined and hardened properties like compressive strength was determined for both ambient curing upto 56 days and higher temperature effect at 56 days for all mix proportions. Research leads to the findings that the specimens made of 10 M NaOH and 30% BIRHA exhibits higher compressive strength at 56 days in ambient temperature beyond which it decreases. The mix made with 90% CFFA and 10% BIRHA is found to be optimum for fire load applications. Hence from the present investigation it can be revealed that the BIRHA is a promising solid waste material for geopolymer application.

Optimization of Silicon Leaching for White Carbon Black Preparation from Vanadium-Extraction Residue Using Response Surface Methodology

Vanadium-extraction residue (VER) is rich in silicon and the high temperature and high pressure alkali leaching can be used to prepare white carbon black (WCB). The effects of the mass ratio of alkali to slag, liquid-solid ratio, reaction temperature and reaction time on the silica leaching ratio were investigated. Response surface methodology was used to analyze the interaction of these main leaching parameters and the final regression equation can be obtained. By using the regression equation, the leaching schemes can be designed as the maximum leaching ratio of silica was set, thereby the optimal leaching parameters also can be obtained to reduce the leaching cost. Repeated experiments showed that the optimized leaching ratio can reach 95.26% which was just lower the predicted value by 2.17%, indicating that the regression equation was reliable to be used to optimize the leaching process. The WCB product with specific surface area of 105.1 m2/g was verified by XRD and FTIR.

Extraction of Si from Alkaline-Roasted Boron Ore Concentrate

The process of alkali roasting boron ore concentrate was proposed for the problems existing in the process of boron ore concentrate smelting. In the paper the influencing factors included molar ratio of alkali to boron ore concentrate, roasting temperature, and roasting time were investigated. The single experiment and orthogonal experiments show the optimal conditions for roasting under the conditions evaluated include a temperature of 550oC, roasting time of 60 min, and a molar ratio of alkali to ore of 3:1. In the roasting process, the Si extraction correlated with the shrinking core model assuming a solid product layer according to XRD and SEM. Thus, the kinetics is controlled by diffusion through the product layer. The apparent activation energy for Si extraction was 13.47kJ•mol-1, and the roasting rate can be expressed as: 1-(2/3α)-(1-α)2/3=1.428×10-2exp(-13470/RT)t

A novel temperature-sensitive cationic hydrophobic cellulose ether: preparation and characterization

A temperature-sensitive polymer—hydroxyl isopropoxy triethyl ammonium chloride cellulose ether—was prepared from hydroxypropyl methyl cellulose (HPMC) and with epoxypropyl triethyl ammonium chloride as the hydrophobization reagent. Then, the reaction conditions of etherification reaction time, mass ratio of the etherifying agent to HPMC, molar ratio of alkali to etherifying agent, and concentration of HPMC were optimized. The structures of the products were characterized via nuclear magnetic resonance and infrared spectrum, and the temperature sensitivity was analyzed via ultraviolet spectrophotometry. It was found that the degree of substitution significantly affected the temperature sensitivity and lowest inversion temperature of the hydroxyl isopropoxy triethyl ammonium chloride cellulose ether. The effects of the substitution degree rising from 0.19 to 0.50 on the water retention value were explored. When the molar ratio of alkali to HPMC was constant, the water retention value declined with the increased substitution degree of cationic cellulose ether. The temperature rise of phase transformation in this process was fully reversible and nonhysteretic. Since the polymer variation originated from the change of intramolecular and intermolecular forces during the heating process, here the effects of addictive micromolecules on the regulator solution were further studied. As the NaOH concentration rose, the substitution degree and water retention value both first increased and then declined and both maximized at the NaOH concentration of 20.7%.

Extraction of alumina from alumina rich coal gangue by a hydro-chemical process.

Vast quantities of gangue from coal mining and processing have accumulated over the years and caused significant economic and environmental problems in China. For high added-value utilization of alumina rich coal gangue (ARCG), a mild hydro-chemical process was investigated to extract alumina. The influences of NaOH concentration, mass ratio of alkali to gangue, reaction temperature and reaction time were systematically studied. An alumina extraction rate of 94.68% was achieved at the condition of NaOH concentration 47.5%, alkali to gangue ratio of 6, reaction temperature of 260°C and reaction time of 120 min. The obtained leaching residues were characterized through X-ray diffraction, scanning electron microscopy and energy-dispersive spectrometer. Research confirmed that kaolinite the main alumina-bearing phase of ARCG can be decomposed and transformed to Na8Al6Si6O24(OH)2(H2O)2 and Ca2Al2SiO6(OH)2 at relatively low temperature and short reaction time. Additionally, Na8Al6Si6O24(OH)2(H2O)2 and Ca2Al2SiO6(OH)2 are unstable and will transform to alumina-free phase NaCaHSiO4 under the optimal conditions, which is the major reason for high alumina extraction rates.

Smart regioselectivity towards mono 6-hydroxyl α-cyclodextrin amphiphilic derivatives.

Following the trend of eco-friendly development, a smart regioselective modification is described herein, for mono 6-hydroxyl and penta-alkyl coexistence on the primary face of α-cyclodextrins with no additional catalysis or no enzyme process, just via the adjustment of the ratio of alkali to alkylation agent, with good yields. The novel procedure minimized the tedious protection, deprotection steps and provided useful intermediates for further cutting edge research. Thus, the scope of green and economical access is extended from penta-pentenyl substitution to C4–C6 alkyl group substitution. It was speculated that the mechanism might be controlled by the concentration of alkali in the system and the steric effects of the electrophilic reagent RBr.

Effect of Na2SiO3/Naoh on the Compressive Strength of Inorganic Polymer Concrete Mixed with Ground Granulated Blast Furnace Slag (GGBS) At Ambient Condition

This paper aims to investigate the influence of alkaline activators solution i.e, Na2SiO3 / NaOH on compressive strength of geopolymer concrete mixed with Ground Granulated Blast furnace slag (GGBS) for constant molarity 8 M. The ratio of alkali to binder ratio is taken as 0.5 and the ratio of Na2SiO3 / NaOH is 2.5. The geopolymer mix is based on pervious sutdies. As per Indian standard size moulds for the cube, cylinder and prism are cast, cured and tested.The specimens were tested for fresh concrete properties such as slump cone test and hardened properties such as compressive strength for cubes, split tensile strength for cylinders and flexural strength for prism different days of curing under ambient temperature. Also, a microstructural study is done by using Scanning electron microscopy (SEM), Energy dispersive X-ray (EDX) for the tested sample. It is found from the test results that, with the aid of alumino-silicate solution, early strength is achieved by geopolymer concrete within 7 days under ambient condition due to the presence of ground granulated slag.

Iron isotope geochemistry and mineralogy of jarosite in sulfur-rich sediments

Jarosite is a common mineral in acidic, sulfate-rich environments where it is critical in regulating the acidity of aquatic systems and the mobility of trace elements and potential contaminants. This research aims to understand jarosite formation and recrystallization in these environments by examining the stable iron isotope geochemistry of jarosite at two coastal sites in Victoria, Australia: Fossil Beach and Southside Beach. Jarosite occurs at high abundance as beds, veins, surface coatings and nodules within oxidized zones of sulfidic sediment outcrops and as pebbles, cobbles, and boulders at the base of the outcrops within the intertidal zone, making these two beaches ideal natural laboratories. Synchrotron powder X-ray diffraction (XRD) and ICP-MS results indicate that samples are comprised predominantly of natrojarosite, often with substantial K substitution. Rietveld refinement of XRD patterns shows that most jarosite samples are a solid-solution of Na-K jarosite, differing from previous observations that (near-)end-member mixing predominantly occurs in nature. The iron isotope composition of the jarosite samples have δ56Fe values between −1.91 and +1.24‰ (relative to IRMM-014), an exceptionally large range that partially overlaps with the δ56Fe values of the sulfidic sediment precursor (−0.54 to +1.30‰). There is a negative relationship between the alkali ratio [Na/(Na + K)] and iron isotope composition, with the heavier iron isotopes preferentially partitioned into K-rich jarosite. The large range in δ56Fe values of jarosite likely results from a combination of the variable δ56Fe values of the precursor sulfides, thermodynamic differences between Na- versus K-bearing jarosite, and an open-system Rayleigh distillation during jarosite formation.

Workability and Strength Properties of Class C Fly Ash-Based Geopolymer Mortar

Fly ash-based geopolymer mortar normally achieves expected properties by heat curing. This becomes one of the obstacles for in-situ applications. The development of high calcium fly ash-based geopolymer mortar, suitable for ambient curing, will gain the applicability of such a material in civil structures. This article reports the results of an experimental study on mortar workability and the increasing of compressive strength of class C fly ash-based geopolymer mortar created in ambient curing condition. The main synthesis parameters such as alkali to the cementitious mass ratio varied from 30% to 40% by an increment of 5% and absolute volume of paste to absolute volume of voids of the aggregate ratio varied from 1 to 2 by an increment of 0.25. These parameters were designed to figure out their individual effects on mortar workability and the mechanical properties for the production of geopolymer mortar. The results suggested that the workability of mortar generally increased by using alkali to the cementitious mass ratio. The compressive strength of 60 MPa and the direct tensile strength of 2.8 MPa, the ratio of alkali to the cementitious mass of 0.35 and absolute volume of paste to absolute volume of voids of the aggregate ratio was 1.5; it was obtained at ambient temperature after 28 days of age. The results will be useful for developing the knowledge for the use of class C fly ash in producing geopolymer concrete, which is currently in progress. Hopefully, this contribution of research will improve the applications of such new binding material in the future.

Leaching behavior and kinetics of vanadium extraction from vanadium-bearing steel slag

The vanadium-bearing steel slag as solid waste is also one of valuable vanadium-containing resource. Recovering vanadium from the refractory steel slag is a great challenge in the world. A leaching process study using high concentration sodium hydroxide solution was proposed in this laboratory work. The effects of sodium hydroxide concentration, particle size, leaching temperature and the ratio of alkali to slag on the rate of vanadium leaching were determined and the leaching kinetics was presented. It indicates that the leaching rate is highly sensitive to the sodium hydroxide concentration and leaching temperature and increases with increasing temperature and sodium hydroxide concentration. By studying the reaction mechanisms, it was found that the dicalcium silicate, tricalcium silicate and calcium ferrited which co-exist with calcium vanadate in the vanadium-bearing steel slag were gradually exposed and reacted with NaOH media to form Na3VO4. The leaching kinetics was analyzed which indicated that the leaching rate is controlled by the chemical reaction with the apparent activation energy of 51.34 kJ/mol. On the basis of this process, the vanadium can be effectively extracted with a leaching rate of more than 80%. The leaching medium can be recycled. It is an effective and cleaner process for leaching vanadium.

Effects of combined usage of GGBS and fly ash on workability and mechanical properties of alkali activated geopolymer concrete with recycled aggregate

Geopolymer binder and recycled aggregates are considered as the two important sustainable ingredients in concrete production. Ground granulated blast furnace slag (GGBS) and fly ash combination based geopolymeric recycled aggregates concretes (GRAC) were prepared as a substitution of normal concrete in order to reduce the consumption of ordinary Portland cement and natural aggregates as well as to make use of demolished waste concrete. The aim of this study is to investigate the combined effects of GGBS and fly ash considering water-binder (W/B) ratio on the fresh and hardened properties of alkali activated GRAC. The slump, setting time, compressive strength, stress-strain relation, elastic modulus, Poisson's ratio, toughness and failure mode of alkali activated GGBS and fly ash based GRAC containing 100% recycled coarse aggregates were experimentally examined. In addition, the hydration mechanisms were studied by XRD and SEM. Finally, the failure mechanism of this kind of novel green concrete subjected to compression was revealed. The results show that GGBS and fly ash exhibits a superior synergetic effect on the performance of GRAC, i.e. fly ash and GGBS are mainly responsible for the workability and mechanical properties, respectively. GGBS/fly ash ratio has a significant influence on the fresh and hardened properties of GRAC. Moreover, the effect of W/B ratio on GRAC strongly depends on the GGBS/fly ash ratio. GGBS content at less than 25% was found to slightly influence the consistency and compressive strength of GRAC. The combination of 50% GGBS and 50% fly ash with a 0.5 W/B ratio could provide excellent mechanical performance and workability for GRAC.

Effect of the Synthesis Method on the Properties of Ultrafine YAG Powder

YAG materials has a number of unique properties, the application is very extensive. In this paper, the superfine YAG powder materials were prepared by co-precipitation method and hydrothermal precipitation method. The influence of synthesis process on the morphology of the powder was investigated. The results showed that the precursor powder prepared via the co-precipitation method is mainly from amorphous to crystalline transition with the increasing calcination temperature, the precursor agglomeration is more serious, In the process of increasing the calcination temperature, the dispersibility of the roasted powder is greatly improved, which is favorable for the growth of the crystal grains, so that the particle size of the powder is gradually increased, the YAG precursor prepared by the co-precipitation method is transformed into YAG crystals, the phase transition occurs mainly between 900 and 1100°C. When the molar ratio of salt to alkali is Y3+: OH-=1: 8 via the hydrothermal reaction, the YAG particles with homogeneous morphology can be obtained. When the molar ratio of salt and alkali is increased continuously, the morphology of YAG particles is not obviously changed. The co-precipitation method is easy to control the particle size, the hydrothermal method is easy to control the particle morphology.

Preparation of Tin Oxide Nanometer Thin Films by Hydrothermal Method

Given the shortage of energy reserves, new energy sources must be identified. In this regard, improving the efficiency of solar cell conversion and simplifying the solar cell technology have become the focus of research. In this study, tin oxide nanometer thin film was fabricated on FTO conductive glass as photocathode through hydrothermal method. The synthesis condition was regulated, and performance test was also conducted. Results show that the crystallization driving force, crystallization rate, and grain size of tin dioxide crystal increase with increasing alkali ratio, leading to disorganized accumulation of tin oxide. Under prolonged holding time, tin oxide crystal became complete, and the surface area of the crystal increased. The crystallization driving force and rate also increased with increasing salt concentration and accompanied by clutter of tin oxide. The optimized process condition included 1:4 molar ratio of salt to alkali, 0.05 mol/L salt concentration, 200 °C reaction temperature, and 8 days of reaction. The highest specific surface area of the tin oxide nanometer film was obtained under the optimized condition.

Formation of epizonal gold mineralization within the Latimojong Metamorphic Complex, Sulawesi, Indonesia: Evidence from mineralogy, fluid inclusions and Raman spectroscopy

The gold deposits within the Latimojong Metamorphic Complex of Sulawesi, Indonesia, including Awak Mas and Salu Bulo, are estimated to host 50 tonnes Au with an average grade of 1.41 g/t. They are located within the metamorphic basement consisting of pumpellyite- to greenschist-facies metasedimentary and metavolcanic rocks, where gold precipitated in quartz veins that fill north-south striking normal faults and extensional fractures. The mineral assemblage is dominated by pyrite, chalcopyrite, galena, minor tetrahedrite-tennantite and sphalerite; gold is electrum with a low silver content (Au:Ag ratio of 8.5 to 9.1). Albite, dolomite-ankerite, siderite, chlorite, and white mica are the main alteration minerals. Quartz, albite and carbonate veins hosting H2O-bearing fluid inclusions with minor aqueous-carbonic phases (CO2 ± N2) were detected (mole fraction <0.15). Raman microspectroscopy, microthermometry, and crush leach analysis of gold-bearing quartz veins and associated host rocks provide evidence for processes resembling those described for epizonal gold mineralization. The gold bearing fluids have salinities between 1.4 and 7.3 eq. mass% NaCl and were trapped in quartz at about 180–250 °C and <1.27 kbar, corresponding to depths less than 5 km. Trapping conditions of barren veins are about 190–390 °C and <1.15 kbar with salinities ranging from 2.2 and 6.1 eq. mass% NaCl. Halogen and alkali ratios (Na/Cl/Br/I) from crush leach analyses correspond to deposits originating from metamorphic fluids with a strong albitization signature during ore formation. Isothermal decompression during the retrogression stage mobilized large volumes of fluids, leading to significant gold mineralization within the Awak Mas District.

Scalable preparation of hierarchical porous carbon from lignin for highly efficient adsorptive removal of sulfamethazine antibiotic

In order to efficiently remove sulfamethazine (SMZ) antibiotic from wastewater, in this work, we first described a facile and scalable synthesis of hierarchical porous carbon using industrial by-product sodium lignosulfonate (SLS) as raw source and potassium hydroxide as inorganic template and chemical activator, by a self-templating and in-situ activation method. The Lignin-derived hierarchical porous carbon obtained at an optimal mass ratio of SLS and alkali of 1:3 (LHPC-3) exhibited a largest specific surface area of 2235m2g−1 and pore volume of 1.512cm3g−1. LHPC-3 possessed a very high saturated monolayer adsorption capacity of 854.7mgg−1 at 288K. The pseudo-second-order rate model described the adsorption kinetics data. It was found that this carbon could be also effective in the high salt environment. Physical adsorption played in an important role in the process of capture SMZ molecules from water. This hierarchical porous carbon had good stability and regeneration property, providing the possibility for the practice application. We gave a novel, simple and effective technique to obtain high-performance hierarchical porous carbon for various use, especially for wastewater treatment.

Co-treatment of spent cathode carbon in caustic and acid leaching process under ultrasonic assisted for preparation of SiC

Spent cathode carbon (SCC) from aluminum electrolysis has been treated in ultrasonic-assisted caustic leaching and acid leaching process, and purified SCC used as carbon source to synthesize silicon carbide (SiC) was investigated. Chemical and mineralogical properties have been characterized by X-ray diffraction (XRD), X-ray fluorescence (XRF), scanning electron microscopy (SEM), and thermogravimetry and differential scanning calorimetry (TGA-DSC). Various experimental factors temperature, time, liquid-solid ratio, ultrasonic power, and initial concentration of alkali or acid affecting on SCC leaching result were studied. After co-treatment with ultrasonic-assisted caustic leaching and acid leaching, carbon content of leaching residue was 97.53%. SiC power was synthesized by carbothermal reduction at 1600 °C, as a result of yield of 76.43%, and specific surface area of 4378 cm2/g. This is the first report of using purified SCC and gangue to prepare SiC. The two industrial wastes have been used newly as secondary sources. Furthermore, ultrasonic showed significant effect in SCC leaching process.

Effects of shell composition, dosage and alkali type on the morphology of polymer hollow microspheres

Polymer hollow microspheres were prepared by performing alkali treatment on the multilayer core/shell polymer latex particles containing carboxyl groups. Effects of the shell composition and dosage as well as alkali type on the morphology of the microspheres were investigated. Results showed that in comparison with acrylonitrile (AN) and methacrylic acid (MAA), using butyl acrylate (BA) as the shell co-monomer decreased the glass transition temperature (T g) of shell effectively and was beneficial to the formation of uniform and big hollow structure. Along with the increase of the shell dosage, the alkali-treated microspheres sequentially presented porous and hollow morphology, and the size of microspheres increased, while the hollow diameter increased first and then decreased, and the maximum hollow ratio reached 39.5%. Furthermore, the multilayer core/shell microspheres had better tolerance to NH3·H2O than to NaOH. When the molar ratio of alkali to methacrylic acid (MRalkali/acid) for NaOH ranged from 1.15 to 1.30 or MRalkali/acid for NH3·H2O ranged from 1.30 to 2.00, the regular polymer hollow microspheres could be obtained.

Process analysis and modeling of a single-step lutein extraction method for wet microalgae.

Lutein is a commercial carotenoid with potential health benefits. Microalgae are alternative sources for the lutein production in comparison to conventional approaches using marigold flowers. In this study, a process analysis of a single-step simultaneous extraction, saponification, and primary purification process for free lutein production from wet microalgae biomass was carried out. The feasibility of binary solvent mixtures for wet biomass extraction was successfully demonstrated, and the extraction kinetics of lutein from chloroplast in microalgae were first evaluated. The effects of types of organic solvent, solvent polarity, cell disruption method, and alkali and solvent usage on lutein yields were examined. A mathematical model based on Fick's second law of diffusion was applied to model the experimental data. The mass transfer coefficients were used to estimate the extraction rates. The extraction rate was found more significantly related with alkali ratio to solvent than to biomass. The best conditions for extraction efficiency were found to be pre-treatment with ultrasonication at 0.5s working cycle per second, react 0.5h in 0.27L/g solvent to biomass ratio, and 1:3 ether/ethanol (v/v) with 1.25g KOH/L. The entire process can be controlled within 1h and yield over 8mg/g lutein, which is more economical for scale-up.

Preparation and Characterization of Precipitated Silica using Sodium Silicate Prepared from Saudi Arabian Desert Sand

The present study reveals a cost benefit process in an open system for utilizing desert sand for preparing sodium silicate or precipitated silica. A simple alkali fusion method has been developed to prepare sodium silicate directly from sand and finally pure precipitated silica by acid precipitation. The reaction weight ratio of alkali to sand reaction parameters are studied for optimizing the silica yield. About 80% pure precipitated silica has been prepared in an open system at 150 °C within 45 min. Wet chemical methods, FTIR, TG-DTA, XRD and SEM techniques are used to characterize the silica prepared from sand available in Saudi Arabian deserts. In the XRD pattern, the peak corresponding to silica was obtained at the diffraction angle of 21.8 ° and it was found to be amorphous in nature.