Two-stream instability in plasma

The problem of two-stream instability in plasma is studied by specifying the importance of initial magnetic field associated with the motion of the charged particles and the boundary effects. In Part I the accurate initial steady state is studied when the streams of electrons and ions move with different uniform speeds in plasmas with plane and cylindrical geometry. In Part II, in order to show the effects of finiteness and inhomogeneity of the system, small transverse plasma oscillations are studied in the case of plane plasmas. The role of plasma-sheath oscillations at the boundaries is found to be very important in driving the instabilities associated with the electromagnetic modes. The numerical estimates of the growth rates of the instability are given for the specific case of the physical data in discharge tubes.

Chemical modification of sheep plasma glycoprotein

Glycoprotein isolated from sheep plasma was chemically modified, and the effect of chemical modification on biological activities and immunological cross reactions has been studied. The removal of sialic acid resulted in a change in the “overall conformation” of the glycoprotein as evidenced by a decrease in viscosity of the glycoprotein solution and an increased susceptibility of the glycoprotein to proteolytic enzymes. Sialic acid-free glycoprotein no longer inhibited the tryptic activity or prolonged the clotting time of plasma. However, it could react with the antiserum to sheep plasma glycoprotein. The periodate oxidation of sheep plasma glycoprotein resulted in a complete loss of inhibition of trypsin activity, prolongation of plasma clotting time, and the ability to cross-react with the rabbit antiserum. The significance of periodate oxidation in relation to the possible sequence of sugars in the carbohydrate prosthetic group in the glycoprotein is discussed. Iodination and heating in buffers of acid and alkaline pH values of sheep plasma glycoprotein resulted in complete loss of trypsin activity and ability to prolong plasma clotting time. Iodination of the glycoprotein did not affect the immunological cross-reactivity.

Physicochemical studies on the gelation of hen's egg yolk: Delipidation of yolk plasma by treatment with phospholipase-C and extraction with solvents

A method for the delipidation of egg yolk plasma using phospholipase-C, n-heptane, and 1-butanol has been described. An aggregating protein fraction and a soluble protein fraction were separated by the action of phospholipase-C. The aggregating protein fraction freed of most of the lipids by treatment with n-heptane and 1-butanol was shown to be the apolipoproteins of yolk plasma, whereas the soluble proteins were identified as the livetins. Carbohydrate and the N-terminal amino acid analysis of these protein fractions are reported. A comparison of these protein fractions with the corresponding fractions obtained by formic acid delipidation of yolk plasma has been made. The gelation of yolk plasma by the action of phospholipase-C has been interpreted as an aggregation of lipoproteins caused by ionic interactions. The role of lecithin in maintaining the structural integrity of lipoproteins has been discussed.

Stability of a cylindrical plasma in the presence of a monotonic field-II

The stability of an incompressible inviscid, perfectly conducting cylindrical plasma against azimuthal disturbances in the presence of a monotonic decreasing magnetic field having a constant pitch is discussed by using energy principle. The results obtained by this principle are compared for m = 1 mode (which is a dangerous mode in which there is a lateral shift of the entire column) with that obtained by normal mode analysis. It is found that m = 1 mode is always unstable. Further, an axial line current, external axial field and the surface tension tend to stabilise m ≠ modes.

Harmonic and anharmonic oscillations of a cylindrical plasma in the presence of a uniform axial magnetic field and a steady axial current

In the present note we have studied the harmonic and anharmonic oscillations of cylindrical plasma using Lagrangian formalism. In order to study the harmonic oscillations, the equations are linearized and the resulting equation for the displacement has been numerically solved. For situations present in thermonuclear reactors, the presence of axial magnetic field is found necessary to make the periods of oscillation to become comparable with the time required for the thermonuclear reactions to set in. A detailed analysis of the anharmonic oscillations reveals that the significant interaction is between the first and the second mode. The fundamental period of anharmonic oscillation is more than the corresponding period of harmonic oscillations by 9·2%. Graphs have been drawn for the amplitudes of relative variations in density and magnetic field and of the time-varying part of anharmonic oscillation.

Electron energy equation for an atomic radiating plasma

The electron-energy equation for an atomic radiating plasma is considered in this work. Using the atomic model of Bates, Kingston and McWhirter, the radiation loss-term valid for all optical thicknesses is obtained. A study of the energy gained by electrons in inelastic collisions shows that the radiation loss term can be neglected only for rapidly-decaying or fast-growing plasmas. Emission from optically thin plasmas is considered next and an exact expression is given for the total radiation loss in a recombination continuum. A derivation of the Kramers-Unsöld approximation is presented and the error involved in estimating the total emitted recombination radiation by this approximation is shown to be small.

Isolation and partial characterization of sheep plasma α1-mucoprotein

1. 1. Sheep plasma α1-mucoprotein was isolated in an electrophoretically homogeneous state by a combination of ammonium sulphate saturation, isoelectric precipitation and preparative agar electrophoresis in a yield of approx. 150 mg/l of plasma. 2. 2. The mucoprotein was water-soluble, non-coagulable on heating at 100°, not precipitable by 1.8 M perchloric acid, 10% trichloroacetic acid but precipitable by saturated ammonium sulphate solution, 0.6 M sulfosalicylic acid and 5% phosphotungstic acid in 2 N HCl. It had E1 cm1 % value of 9.57 at 278 mμ in water, refractive-index index increment 1.9·10-4 (g/l) in water, isoelectric point at pH 4.45 (sodium acetate-acetic acid buffer) and was homogeneous in pH range 4.0-11.5 but at pH values 2.6 and 3.5 showed some dissociation. 3. 3. The mucoprotein had the following chemical composition: Nitrogen, 12.4%; polypeptide, 77.4%; total hexose (only mannose and galactose), 7.1%; fucose, 1.0%; glucosamine, 4.9% and sialic acid, 4.8%. It had no N-terminal amino acid.

Pt2+ Dispersed in Ce0.83Ti0.15O2-delta: Significant Improvement in PROX Activity by Ti Substitution in CeO2 in Hydrogen Rich Stream

Pt2+ ion dispersed in CeO2, Ce1-xTixO2-delta and TiO2 have been tested for preferential oxidation of carbon monoxide (PROX) in hydrogen rich stream. It is found that Pt2+ substituted CeO2 and Ce(1-x)TixO(2-delta) in the form of solid solution Ce0.98Pt0.02O2-delta and Ce0.83Ti0.15Pt0.02O2-delta are highly CO selective low temperature PROX catalysts in hydrogen rich stream. Just 15% of Ti substitution in CeO2 improves the overall PROX activity.

Geochemistry of fluoride rich groundwater in Kolar and Tumkur Districts of Karnataka

Groundwater is a significant water resource in India for domestic, irrigation, and industrial needs. By far the most serious natural groundwater-quality problem in India, in terms of public health, derives from high fluoride, arsenic, and iron concentrations. Hydrogeochemical investigation of fluoride contaminated groundwater samples from Kolar and Tumkur Districts in Karnataka are undertaken to understand the quality and potability of groundwater from the study area, the level of fluoride contamination, the origin and geochemical mechanisms driving the fluoride enrichment. Majority of the groundwater samples did not meet the potable water criteria as they contained excess (>1.5 mg/L) fluoride, dissolved salts (>500 mg/L) and total hardness (75-924 mg/L). Hydrogeochemical facies of the groundwater samples suggest that rock weathering and evaporation-crystallization control the groundwater composition in the study area with 50-67% of samples belonging to the Ca-HCO3 type and the remaining falling into the mixed Ca-Na-HCO3 or Ca-Mg-Cl type. The saturation index values indicated that the groundwater in the study area is oversaturated with respect to calcite and under-saturated with respect to fluorite. The deficiency of calcium ion concentration in the groundwater from calcite precipitation favors fluorite dissolution leading to excess fluoride concentration.

Photocatalytic Activity of Microwave Plasma-Synthesized TiO2 Nanopowder

Nanocrystalline TiO2 was synthesized using the microwave plasma technique and characterized using X-ray diffraction, transmission electron microscopy, scanning electron microscopy, laser particle size analyzer, UV-vis spectroscopy and BET surface area analyzer. The synthesized TiO2 powder crystallized in anatase phase and the crystallite sizes were in nanometers. The photocatalytic activity of the compound was determined and compared against the activity of the commercial Degussa P-25 TiO2 catalyst. The degradation rates of the dyes were found to be higher over the synthesized TiO2 as compared to that over commercial Degussa P-25 TiO2.

Moral Education in the Japanese Primary School Curricular Revision at the Turn of the Twenty-first Century: Aiming at a Rich and Beautiful Kokoro

This study examines values education in Japanese schools at the beginning of the millennium. The topic was approached by asking the following three questions concerning the curricular background, the morality conveyed through textbooks and the characterization of moral education from a comparative viewpoint: 1) What role did moral education play in the curriculum revision which was initiated in 1998 and implemented in 2002? 2) What kinds of moral responsibilities and moral autonomy do the moral texts develop? 3) What does Japanese moral education look like in terms of the comparative framework? The research was based on curriculum research. Its primary empirical data consisted of the national curriculum guidelines for primary school, which were taken into use in 2002, and moral texts, Kokoro no nôto, published by the Ministry of Education in the same context. Since moral education was approached in the education reform context, the secondary research material involved some key documents of the revision process from the mid-1990s to 2003. The research material was collected during three fieldwork periods in Japan (in 2002, 2003 and 2005). The text-analysis was conducted as a theory-dependent qualitative content analysis. Japanese moral education was analyzed as a product of its own cultural tradition and societal answer to the current educational challenges. In order to understand better its character, secular moral education was reflected upon from a comparative viewpoint. The theory chosen for the comparative framework, the value realistic theory of education, represented the European rational education tradition as well as the Christian tradition of values education. Moral education, which was the most important school subject at the beginning of modern school, was eliminated from the curriculum for political reasons in a school reform after the Second World War, but has gradually regained a stronger position since then. It was reinforced particularly at the turn of millennium, when a curriculum revision attempted to respond to educational and learning problems by emphasizing qualitative and value aspects. Although the number of moral lessons and their status as a non-official-subject remained unchanged, the Ministry of Education made efforts to improve moral education by new curricular emphases, new teaching material and additional in-service training possibilities for teachers. The content of the moral texts was summarized in terms of moral responsibility in four moral areas (intrapersonal, interpersonal, natural-supranatural and societal) as follows: 1) continuous self-development, 2) caring for others, 3) awe of life and forces beyond human power, and 4) societal contribution. There was a social-societal and emotional emphasis in what was taught. Moral autonomy, which was studied from the perspectives of rational, affective and individuality development, stressed independence in action through self-discipline and responsibility more than rational self-direction. Japanese moral education can be characterized as the education of kokoro (heart) and the development of character, which arises from virtue ethics. It aims to overcome egoistic individualism by reciprocal and interdependent moral responsibility based on responsible interconnectedness.

Interrelations between Dry Eye Syndrome and Tear Fluid Phospholipid Transfer Protein

The simplified model of human tear fluid (TF) is a three-layered structure composed of a homogenous gel-like layer of hydrated mucins, an aqueous phase, and a lipid-rich outermost layer found in the tear-air interface. It is assumed that amphiphilic phospholipids are found adjacent to the aqueous-mucin layer and externally to this a layer composed of non-polar lipids face the tear-air interface. The lipid layer prevents evaporation of the TF and protects the eye, but excess accumulation of lipids may lead to drying of the corneal epithelium. Thus the lipid layer must be controlled and maintained by some molecular mechanisms. In the circulation, phospholipid transfer protein (PLTP) and cholesteryl ester transfer protein (CETP) mediate lipid transfers. The aim of this thesis was to investigate the presence and molecular mechanisms of lipid transfer proteins in human TF. The purpose was also to study the role of these proteins in the development of dry eye syndrome (DES). The presence of TF PLTP and CETP was studied by western blotting and mass spectrometry. The concentration of these proteins was determined by ELISA. The activities of the enzymes were determined by specific lipid transfer assays. To study the molecular mechanisms involved in PLTP mediated lipid transfer Langmuir monolayers and asymmetrical flow field-flow fractionation (AsFlFFF) was used. Ocular tissue samples were stained with monoclonal antibodies against PLTP to study the secretion route of PLTP. Heparin-Sepharose affinity chromatography was used for PLTP pull-down experiments and co-eluted proteins were identified with MALDI-TOF mass spectrometry or Western blot analysis. To study whether PLTP plays any functional role in TF PLTP-deficient mice were examined. The activity of PLTP was also studied in dry eye patients. PLTP is a component of normal human TF, whereas CETP is not. TF PLTP concentration was about 2-fold higher than that in human plasma. Inactivation of PLTP by heat treatment or immunoinhibition abolished the phospholipid transfer activity in tear fluid. PLTP was found to be secreted from lacrimal glands. PLTP seems to be surface active and is capable of accepting lipid molecules without the presence of lipid-protein complexes. The active movement of radioactively labeled lipids and high activity form of PLTP to acceptor particles suggested a shuttle model of PLTP-mediated lipid transfer. In this model, PLTP physically transports lipids between the donor and acceptor. Protein-protein interaction assays revealed ocular mucins as PLTP interaction partners in TF. In mice with a full deficiency of functional PLTP enhanced corneal epithelial damage, increased corneal permeability to carboxyfluorescein, and decreased corneal epithelial occludin expression was demonstrated. Increased tear fluid PLTP activity was observed among human DES patients. These results together suggest a scavenger property of TF PLTP: if the corneal epithelium is contaminated by hydrophobic material, PLTP could remove them and transport them to the superficial layer of the TF or, alternatively, transport them through the naso-lacrimal duct. Thus, PLTP might play an integral role in tear lipid trafficking and in the protection of the corneal epithelium. The increased PLTP activity in human DES patients suggests an ocular surface protective role for this lipid transfer protein.

Photochemistry of .alpha.,.beta.-unsaturated thiones: addition to electron-rich olefins from T1

1,1,3-Trimethyl-2-thioxo-1,2-dihydronaphthale(1n)e adds to electron-rich olefins upon excitation to either Sz (PP*) or Sl (ns*) states. Excitation to S2 level resulted in the same mixture of products, namely thietane and 1,4-dithiane, as on excitation to S1 level. Addition occurs to the thiocarbonyl function and not to the carbon-carbon double bond. The addition is site-specific, and the formation of thietane is regiospecific. The ratio of thietane to 1,4-dithiane in the product mixture is dependent on the concentration of the thioenone. The addition is suggested to originate from the lowest triplet state (Tl) and involves diradical intermediates.