Earth alkali elements

The Okuaizu geothermal system is characterized by high temperatures (maximum 340°C), high salinity (about 2 wt% total dissolved solids (TDS)) and large amounts of non-condensable gases (1 wt% CO2 and 200 ppm H2S). The pH of the hydrothermal solution measured at 25°C is 6.44 (Table 2.6). However, the pH of the original fluid in the reservoir is computed to be 4.05. This pH as well as alkali and alkali earth element concentrations are plotted near the equilibrium curve of albite, K-mica, anhydrite and calcite (Fig. 2.19) (Seki, 1991). 

Chemical compositions of major elements (alkali, alkali earth elements. Si) in back-arc and midoceanic ridge hydrothermal solutions are not so different (Table 2.15). This is thought to be due to the effect of water-rock interaction. For example, Berndt et al. (1989) have shown that mQ i+ of midoceanic ridge hydrothermal fluids is controlled by anorthite-epidote equilibrium (Fig. 2.37). Figure 2.37 shows that /Mca2+/m + of back-arc hydrothermal fluids is also controlled by this equilibrium. 

Shikazono (1978) theoretically derived that the concentrations of alkali and alkali earth elements in chloride-rich hydrothermal solution are nearly in equilibrium with hydrothermal alteration minerals such as albite, K-feldspar, K-mica, quartz, calcite, wairakite, and Mg-chlorite. If we use 500 mmol/kg H2O as the average Cl concentration of hydrothermal solution from the back-arc basin, which is in equilibrium with... 

Davy also discovered several other elements (potassium, barium, calcium, and strontium) by isolating the metals from their compounds through electrolysis. His work led to the development of electrochemistry, which is the use of electricity as the energy source to break up the oxides of these alkali and alkali earth elements. 

Zeolites are crystalline aluminosilicates of alkali or alkali earth elements such as sodium, potassium, and calcium and are represented by the stoichiometry ... 

Barium is present at very low concentrations in most environmental samples. Thus, in spite of the availability of a detection limit of only a few ng ml 1 by flame AES, the element is rarely determined by flame methods AAS with electrothermal atomization or ICP-AES is more commonly used. A notable exception is in the determination of the element in barium-rich geological deposits.8 Another exception is in the analysis of formation waters from offshore oil wells.9 However, in this matrix, inter-element interferences are encountered from alkali and alkali-earth elements. These could be effectively eliminated by the addition of 5 g 1 1 magnesium and 3 g 1 1 sodium as a modifier.9... 

The history of atomic emission spectrometry (AES) goes back to Bunsen and Kirchhoff, who reported in 1860 on spectroscopic investigations of the alkali and alkali earth elements with the aid of their spectroscope [1], The elements cesium and rubidium and later on thorium and indium were also discovered on the basis of their atomic emission spectra. From these early beginnings qualitative and quantitative aspects of atomic spectrometry were considered. The occurrence of atomic spectral lines was understood as uniequivocal proof of the presence of these elements in a mixture. Bunsen and Kirchhoff in addition, however, also estimated the amounts of sodium that had to be brought into the flame to give a detectable line emission and therewith gave the basis for quantitative analyses and trace determinations with atomic spectrometry. 

The alkali earth elements represents a major variable in cotton fibre (Table 4.2) and mainly comes from cotton seed husks. Further the use of hard water can precipitate alkali earth metal phosphates on the fibre instead of eliminating them [2]. The reason for reddish shade after bleaching with peroxide is the high content of manganese, Mn -> colourless but Mn violet. The contents of Fe, Mn, Ca and... 

Worldwide, there are no methods for the selective extraction of strontium from substrates containing high concentrations of calcium. An effective method for extraction of strontium from exhaust iodine-lwomine plants consists of the sequential sedimentation of alkali earth elements. For this purpose the solubility of a multi-component system such as Na, k, Mg Ca Sr // Cl, OH -H O Na K", Ca Sr " // Cl, -H O, was investigated... 

The process for subsequent extraction of alkali earth elements from mineralized effluents rom the iodine-txomine production in Turkmenistan includes the investigation of the possibility of isolating calcium and strontium from sodium hydroxide solutions. 

Mg and Ca are the eighth and sixth most abundant elements in Earth s crust at 2.5 and 3.6 percent, respectively. Be, Sr, and Ba comprise 0.001, 0.025, and 0.05 percent, respectively. Ra is radioactive, and since its longest-lived isotope Ra has a half-life of 1,600 years, there is very little Ra in Earth s crust. It is nonetheless present because Ra is continuously formed by the decay of uranium ( U). Alkali earth elements are... 

The alkali metals and alkaline earth elements are generally present in suflBcient quantities to be analyzed directly without concentration. Flame emission is preferable for the alkalies because of its good sensitivity and few interferences in the analysis of this class of elements in waters and because the technique eliminates the need for hollow cathode lamps. For the alkali earth elements, the flame emission method is still applicable, but with some problems owing to chemical interferences in some waters. Atomic absorption is preferred for this class of elements and although the chemical interference problem still exists, it is not as serious as in flame emission. Those elements present in amounts less than... 

To get the ball rolling we introduce hydrogen in Chapter 10, because it s the most abundant element in the universe and can be found in many chemicals and materials. We then move from left to right on the periodic table, starting off with the alkali and alkali earth elements in Chapter 11. We guide you through the periodic table to the main group elements in Chapter 12, the transition metals in Chapter 13, and finally round out Part III with the lanthanides and actinides in Chapter 14. 

Flame AES is used commonly to determine alkali and alkali earth elements in oxide glasses, using the parameters shown in Table 2. 

Inspecting Figs. 14.3, 14.4 14.5 and Table 14.1 shows that, as stated earlier for Bi -doped alkali or alkali-earth borate binary glasses, the excitation peak regularly shifts red and the emission peak shifts blue with increasing concentration of alkali or alkali-earth elements. As a result, the Stokes shift decreases. How does all this happen To elucidate it, information on glass microstructural changes is helpful. 

Today, on the other hand, glass ceramics are widely used for ceramic multilayer substrate with Ag and Cu as an inner conductor. About 40—50% of grass elements such as AI2O3, SiOi, MgO and alkali-earth elements compose the dielectrics, which can sinter at relatively lower temperature (<900°C). 

Approximately half of the amounts of alkali and alkali earth elements (K, Na, Ca, Mg) comes from dissolution of silicates, and the others from salt (evaporate) and carbonates. The concentrations of these elements in ground water can be interpreted based on dissolution and precipitation of silicates. 

At the later end of temporal plasma history, after long delay times very important analytical information was revealed. For example, spectra from diatomic molecules of halogens and alkali-earth elements were detected after a 25 ps delay these spectra enable fluorine and chlorine detection much more easily than the traditional F and Cl ionic lines. After a delay of more than 100 ps, sometimes plasma-induced luminescence was detected it is very effective for rare-earth elements identification. 

Iron surfaces are covered by the double-layer of promoter oxides. The first one of sublayers close to iron atoms is filled with oxygen atoms and shows the free adsorption sites the second sublayer is present on the top of the first sublayer, and is filled with the promoter atoms. The amount of oxygen atoms and the free adsorption sites are decided by the properties of promoters (Fig. 3.71), of which the former is in a fixed proportion to that of promoter atoms. Under the anunonia synthesis conditions, the ratio of the number of oxygen atoms to the nmnber of promoter atoms located on the iron surface is constant and equal to the valence of the promoter (for alkali metals, 122,125,161,162. alkali earth elements, 2 1 ... 

It is not clear when dithiocarbamates were first prepared, but certainly they have been known for at least 150 years, since as early as 1850 Debus reported the synthesis of dithiocarbamic acids (1). The first synthesis of a transition metal dithiocarbamate complex is also unclear, however, in a seminal paper in 1907, Delepine (2) reported on the synthesis of a range of aliphatic dithiocarbamates and also the salts of di-iTo-butyldithiocarbamate with transition metals including chromium, molybdenum, iron, manganese, cobalt, nickel, copper, zinc, platinum, cadmium, mercury, silver, and gold. He also noted that while dithiocarbamate salts of the alkali and alkali earth elements were water soluble, those of the transition metals and also the p-block metals and lanthanides were precipitated from water, to give salts soluble in ether and chloroform, and even in some cases, in benzene and carbon disulfide. 

The purification of exhaust gases from burners working on liquid and gas fuel is accomplished by using oxidation catalysts of Perrovski t3 e oxides - ABO3 combined with ozonation. Ozone is injected prior the waste gases flow. A may be La, Pr or other alkali earth element B may be Co, Mn or other transition metal. A may be also partially substituted by Sr, Ca or any other alkali earth element. A catalyst deposited on ceramic support of honeycomb type may contain SrCOgjMnp Oj. It is oxidized 24% CO in the absence of ozone and 80% in ozone atmosphere [14]. 

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