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A spectral theory is developed for the solar semidiurnal tides in an atmosphere with background zonal winds. According to this theory, the vertical structures of the spectral components of the tide are governed by a set of coupled second-order ordinary differential equations which have to be solved for appropriate lower and upper boundary conditions. The lower boundary condition, in particular, has to be properly formulated to take into account the latitudinal variation of the atmospheric basic-state parameters. While the solutions to the equations have to be obtained by numerical methods, several aspects of their behavior can be revealed by simpler mechanistic models and concepts which are introduced in this first part (Part I) of a two-part report. Discussion of the detailed numerical solutions and of the adequacy of their mechanistic interpretations is given in the companion paper (Part II).

Starting from a seven-membered ring compound, the synthesis of thetricyclic ketone ( 25 ) is described concluding a formal total synthesis of (±) isoclovene, the major sesquiterpene from extensive rearrangement ofcaryophyllene. Enroute, a facile base promoted epimerisation and consequent ketone assisted hydrolysis of ketonitrile (12) under mild conditions was observed.

A mathematical model has been developed to predict the operating behavior of an SL/RN direct reduction kiln from a knowledge of the main process variables. The model is based on steady state principles and is capable of quantitatively describing the different chemical reactions in the kiln such as reduction, Boudouard reaction, coal devolatilization, combustion in the freeboard together with the mass and heat flows. Results of the model, which are in the form of axial temperature profiles in the freeboard gas, solids bed and wall, and axial concentration profiles in the gas and solids, are in good agreement with measurements made on a 200 ton per day pilot plant at the Steel Company of Canada. The model has been used both to investigate the influence of process variables on the kiln performance and to elucidate operating features of the process. The model has shown that highly reactive coals such as subbituminous and lignite, and highly reducible pellets are most suitable for the SL/RN process. It has also demonstrated that the most important process variable from the standpoint of control is the air profile in the kiln; and consequently that heat transfer is the rate controlling step. The model has also been employed to examine scale-up of the SL/RN process by calculating the operating behavior of a large commercial kiln. It has shown that the large kiln should run cooler than the pilot-size unit so that accretion problems may be significantly reduced.

Classical and nonclassical model calculations have been performed for the solar semidiurnal tidal oscillations in the earth's atmosphere, for prescribed basic-state parameters and heating functions appropriate for the solstitial seasons when the nonclassical effects associated with the mean zonal wind are expected to be maximum. It is found that the enrichment of the higher order spectral components characteristic of the nonclassical model is due to the cross-coupling rather than the self-coupling of the spectral components in the model. These cross-coupling effects are shown to be sufficiently well represented by a mode-coupling model described in Section 3 of Part I. As explained in Part I, the effect of cross-coupling may be considered as some kind of indirect forcing. Such indirect forcing, which can be applied either at the lower boundary or inside the medium, is obtained and compared for each spectral component with the direct thermal forcing. It is demonstrated that the actual behavior of ...

Using ground magnetometer data from several stations near the dip equator, the magnetically quiet-time characteristics of the daytime normal electrojet and the morning and afternoon counter-electrojets are established and illustrated. In particular, the solar cycle, seasonal, longitudinal and day-to-day variations of counter-electrojets as well as their dependence on lunar phase are studied. In order to investigate the influence of solar tidal winds in the production of counter-electrojets, the equatorial electric fields generated by such winds through the dynamo mechanism are calculated, using a numerical dynamo simulation model developed earlier at UCLA. From these calculations it is found that westward electric fields responsible for the afternoon counter-electrojets can be produced in the local summer solstice (when these events are most common) by a combination of the solar semidiurnal (2, 2) tide and the diurnal (1, -2) tide. An example from January 1964 is discussed to illustrate that afternoon counter-electrojet events occurring at all longitudes on the same day are likely to be associated with abnormalities in the global Sq or SR current system. It is suggested that the lunar semi-diurnal tide is a more important causative agent for the morning rather than the afternoon counter-electrojets.

Calculations of the semidiurnal atmospheric tide at solstice using improved heating rates are presented. The heating rates for solar absorption by water vapor are based on a global water vapor distribution (Jenne, 1969, 1975; Jenne et al., 1974), the data of McClatchey et al. (1972), and an absorptivity parameterization of Lacis and Hansen (1974); rates for solar absorption by ozone are based on the midlatitude ozone distribution of the U.S. Standard Atmosphere (COESA, 1976) and detailed radiative calculations using the solar fluxes and absorption cross sections of Ackerman (1971) with the Schumann-Runge band cross sections of Kockarts (1971). The heating rates for solstice are quite similar to those reported by Forbes and Garrett (1978) and significantly different from those of Lindzen and Hong (1974), which were used in the previous study of Walterscheid and Venkateswaran (1979b) investigating the influence of mean zonal motion and meridional temperature gradients on the solar semidiurnal tide....

We pose and answer two questions about solutions of the linear complementarity problem (LCP). The first question is concerned with the conditions on a matrix M which guarantee that for every vector q , the solutions of the LCP ( q , M ) are identical to the Karush-Kuhn-Tucker points of the natural quadratic program associated with ( q , M ). In answering this question we introduce the class of “row sufficient” matrices. The transpose of such a matrix is what we call “column sufficient”. The latter matrices turn out to furnish the answer to our second question, which asks for the conditions on M under which the solution set of ( q , M ) is convex for every q . In addition to these two main results, we discuss the connections of these twonew matrix classes with other well-known matrix classes in linear complementarity theory.

Short and convenient synthesis of bicyclic lactones (1) and (2), important intermediates in trichothecene synthesis is described.

The chemiluminescent reaction responsible for the nightglow in the sodium D lines is embedded in the complex kinetics of an oxygen-hydrogen atmosphere. Various possibilities of identifying this reaction from observational studies are considered. It is suggested that an important clue may be found in the time-variations of the height-integrated glow-intensity.

Ionospheric E-region observations from Boulder (40.0 N, 105.3 W), Grand Bahama (26.6 N, 78.2 W), Mexico City (19.3 N, 99.2 W), Vandenberg (35.6 N, 120.6 W), and Wallops Island (37.9 N, 75.5 W) during the total solar eclipse of 7 March, 1970 are used for reconstructing the distribution of the ionizing XUV radiation over the solar disk. The derived solar image compares reasonably well with the EUV and X-ray pictures of the Sun obtained from rockets.

An attempt is made in this paper to formulate the transport of hydrogen in the earth's upper atmosphere as a Monte Carlo problem. The relevant details of the technique adopted are given. The capability of the technique to provide useful answers to the following questions is demonstrated. How is the flux of hydrogen atoms, possessing enough kinetic energy to escape from the earth's gravitational field, influenced by the fact that the escape takes place not from a particular atmospheric level (the critical level) but from a layer of finite thickness? What is the law of variation of hydrogen density in this finite layer? More specifically, does the hydrogen gas maintain a Maxwellian distribution while diffusing through the layer? If not, how does the distribution change with height inside the layer? The answers obtained are discussed with reference to their statistical validity, and compared with some of the conclusions of earlier investigations.

It is shown that time-structure analysis of geomagnetic crochets can be useful in the ground-based detection of XUV radiation from solar flares. The crochets often manifest a composite structure that consists of a ‘fast’ component presumably produced by EUV radiation (100–1000A) and a ‘slow’ component produced by soft X rays (1–100A). This composite structure is taken into account in the proposed method of analysis for crochet current systems. Some preliminary results are given from the simulation studies of Sq and crochet current systems. These studies are intended to probe into the nature of the atmospheric winds that drive the ionospheric dynamo and that generate both the Sq and crochet currents.

A brief description of the Vaisala radiosonde is given and its general performance-characteristics discussed. Some results of ascents made at Ahmedabad with this type of instrument in the last two years are presented. The question of the diurnal variation of temperature in the upper atmosphere is examined with reference to the serial ascents made in the month of April 1952.

The hydroxyl bands in the glow emanating from the earth's upper atmosphere are chemically excited. The two possible precursor reactions are O3+H→OH*+O2 and O2*+H→OH*+O. Arguments are advanced in this paper to show that the night-time variations of the emission intensifies stimulated by these two reactions might be characteristically different. The relative importance of the reactions can therefore be judged by a systematic observational study of the intensity variations.

The paper describes the techniques developed at Poona for the measurement of electrical potential gradient in the free atmosphere and discusses the results of the observations made over Poona during 1953–1958. The day-to-day and diurnal variations of potential gradient in the troposphere as well as the seasonal variations are discussed. The variation of potential gradient with height follows the theoretical values only during the monsoon months, showing an increase above 300 mb in winter and steady values above 500 mb during summer.

The lower atmospheric wind structure over Ahmedabad has been studied from a detailed. analysis of one complete year's observations. It is found that the local winds introduced by the orographical peculiarities of the surrounding country are (1) the katabatic wind that comes as. a Northeasterly current extending to a depth of about 0'15 to 0,25 km in the months of October to January and (2) the sea breeze that reaches from ,the Gulf of Cambay in the hot months just prior to and after the local monsoon. A seasonal examination of the pilot balloon winds shows that the nature of the diurnal variation of wind is governed mainly by the amount of turbulence in the frictional layer. This variation is confined to about'3000 ft in winter and extends to a greater from the Gulf height in summer. It is also shown how, in the winter months, both the wind and temperature distributions help in the formation of a very stable layer just above 3000 ft limiting the upper reach of surface turbulence.

This paper is an observational study of the equatorial anomaly during a period of declining solar activity. The anomaly is studied at two different longitudes, 75°W and 105°E. Data from both the topside and the bottomside of the F region are used. The topside data were obtained by the satellite Alouette 1. Seasonal and daily variations, longitude dependence, and geomagnetic storm-time distortions of the anomaly are treated.

This report presents the experience of the authors with varioustechniques and also the results obtained by employing a pedicled composite bonemuscle graft in Tracheal Stenosis.

International audience; In the paper "Saint-Santin Radar Observations of Lower Thermospheric Storms" by C. Mazaudier, R. Bernard and S.V. Venkateswaran (Journal of Geophysical Research 90 (A3), 2885-2895) the name of the third author was inadvertently omitted from the first page. A corrected first page follows

High purity, submicron silicon carbide powders were produced via gas phase synthesis using a hydrogen/argon plasma. Two test facilities were constructed, a bench-scale unit and a larger pilot scale reactor. Three candidate silicon sources were evaluated:silicon tetrachloride (SiCl{sub 4}). dimethyldichlorosilane (CH{sub 3}){sub 2}(SiCl{sub 2}) and methyltrichlorosilane (CH{sub 3}SiCl{sub 3}). Product powders were evaluated on the basis of pressureless sinterability, surface area, agglomeration, particle size distribution, phase distribution and chemistry. Three commercial powders, Starck A10, Starck B10, and Carborundum submicron alpha silicon carbide, were also evaluated for comparison to the product powders. Powders were reproducibly synthesized at a rate of one pound per hour for standard run times of five hours. Product powders exhibited chemical and physical properties equal to or exceeding the commercial powders evaluated. In limited attempts to pressureless sinter the product powders, densities of 91% of theoretical were obtained with as-produced powder. Post-processing permitted densities in excess of 97% of theoretical. X-ray diffraction of the product indicates that the product powders are primarily beta poly-types, with traces of alpha present. Increased production rates to a target level of seven pounds per hour were not possible due to current transients produced by the pilot scale power supply. Extensive unsuccessfulmore » efforts to reduce or eliminate the transients are described. Low recovered product yields resulted from a failure of a product collection filter that was not discovered until the completion of the project.« less

La reaction d'esters primaires avec le carbonate de dimethyle en presence d'hydrure de sodium donne les malonates methyles correspondants

Analysis of 29 days of ionospheric current data obtained by Saint-Santin radar, including both magnetically quiet and disturbed periods, has confirmed the existence of northward currents at all daytime hours. The postulate of field-aligned Van Sabben currents driven by interhemispherical asymmetries seems to be able to account for the anomaly. The desirability of quantitative modeling of the Van Sabben currents on a seasonal or day-to-day basis is highlighted by the Saint-Santin measurements.

Acid-catalysed rearrangement of cyclobutachromenol (7) followed by oxidation furnishes the tricyclic ketone (9) as the major product, which possesses the carbocyclic framework of aplysin (3).

Short and convenient synthesis of bicyclic lactones (1) and (2), important intermediates in trichothecene synthesis is described.

Reaction of 2,2-disubstitutted cyclopentanones ( 1a–d ) with bromine followed by aqueous alkali furnishes the 5,5-disubstituted 2-hydroxycyclopent-2-en-1-ones which were transformed to the 3,3-disubstituted cyclopentanones by reduction with hydriodic and acetic acids.

Photolytic Wolff rearrangement of α-diazocyclopentanones ( 3a-c ) in methanol leads to the cyclobutane carboxylates ( 4a-d ).

Acid-catalysed rearrangement of cyclobutachromenol (7) followed by oxidation furnishes the tricyclic ketone (9) as the major product, which possesses the carbocyclic framework of aplysin (3).

A synthesis in the racemic form of the title sesquiterpene artifact is reported involving stereocontrolled transformation of keto-nitrile ( 4 ) to diketone ( 12 ). A facile epimerisation and consequent ketone asisted hydrolysis of ( 4 ) under mild basic conditions is observed.

This paper develops the linear gradient drift instability theory of middle latitude E/sub S/ -layer irregularities, taking into account the appropriate field geometry and allowing for the fact that, in addition to a predominant perpendicular component, the propagation vector of an irregularity can have a small but significant component parallel to the magnetic field as well. The theory is used to calculate the growth rates and phase and group velocities of the unstable waves as a function of the off-perpendicular propagation angle. Group propagation effects are also considered.

A short and high yield synthesis of the marine sequiterpenoids Debromoaplysin (2) and Aplysin (1) is reported involving intramolecular ketene–alkene cycloaddition as a key step.

Stereospecific syntheses of 10α-hydroxy-1,1,4aβ,8aβ-tetramethyl-trans-transoid-trans-2,3,4,a,4b,5,7,8,8a,9,-10,10a-dodecahydrophenanthren-6(1H)-one (9) and 1,1,4aβ,8aβ-tetramethyl-8β-(3-methylpentanoyl)-2,3,4,4a,-4b,5,7,8,8a,9-decahydrophenanthren-6(1H)-one (15), potential intermediates for cheilanthatriol, are described. A few related transformations examined during these studies are discussed.