Hydrodynamical instabilities induced by atomic diffusion in A stars and their consequences

Aims. Atomic diffusion, including the effect of radiative accelerations on individual elements, leads to important variations of the chemical composition inside the stars. The accumulation in specific layers of the elements, which are the main contributors of the local opacity, leads to hydrodynamical instabilities that modify the internal stellar structure and surface abundances. Our aim is to study these effects and compare the resulting surface abundances with spectroscopic observations Methods. We computed the detailed structure of A-type stars including these effects. We used the Toulouse-Geneva Evolution Code (TGEC), where radiative accelerations are computed using the Single Valued Parameter (SVP) method, and we added double-diffusive convection with mixing coefficients deduced from three-dimensional (3D) simulations. Results. We show that the modification of the initial chemical composition has important effects on the internal stellar mixing and leads to different surface abundances of the elements. The results fit the observed surface chemical composition well if the layers, which are individually mixed by double-diffusive convection, are connected.Comment: 7 pages, 7 figures, accepted in A&

CORPORATIONS--FOREIGN CORPORATIONS--DOING BUSINESS BY AGENTS--COMITY

The plaintiff, an Illinois corporation, offered correspondence courses in refrigeration and air conditioning. One of its agents solicited the defendant in Lincoln, Nebraska. The defendant signed a contract and promissory note for the tuition and made an advance payment, whereupon the agent forwarded the contract, note, payment and other papers to the home office of the plaintiff corporation in Chicago, Illinois. The plaintiff accepted the contract in Illinois. After six months, the defendant refused to proceed with the lessons or make further payments in accordance with the contract. The plaintiff sued for the balance due on the note. The Nebraska statute made it unlawful for a representative of any school, domestic or foreign, while soliciting in the state, to receive a note or contract for tuition unless the note had the words Negotiable note given for tuition written prominently thereon, or the contract was inscribed Negotiable contract note given for tuition and scholarship. The statute, among other penalties, provided that a note or contract which failed to comply with its terms was void. The contract and note in question did not comply with this Nebraska statute. Held, although the contract may be considered an Illinois contract and perfectly valid by the laws of that state, the plaintiff may not enforce it in Nebraska. A foreign corporation under such circumstances possesses no greater rights than a domestic corporation, and when it solicits business in Nebraska contrary to its law, a contract growing out of such transaction, though finally consummated and valid in another state, if invalid in Nebraska, will not be enforced there as a matter of comity. Refrigeration & Air Conditioning Institute, Inc. v. Hillyard, (Neb. 1945) 18 N.W. (2d) 548

WILLS--SPECIFIC BEQUEST OF CAPITAL STOCK--DISPOSITION OF STOCK DIVIDENDS DECLARED BEFORE TESTATOR\u27S DEATH

In her will, testatrix made several specific gifts to Miss Dorothy Spencer, including 20 shares of stock of the Times-Picayune Publishing Company, the extent of her holding at the time the will was executed. Later, the company declared a 100 per cent stock dividend and issued testatrix a certificate for an additional 20 shares. When she died, testatrix had in her possession certificates for 40 shares of the corporation\u27s stock. Ten legatees objected to a provisional account filed by her executor which listed the 40 shares as belonging to Dorothy Spencer, claiming that the additional shares should be converted into money and applied to a deficit in the amount available to pay the ten cash legacies. Held, the will passed the entire 40 shares to Miss Spencer because by its provisions testatrix bequeathed to Miss Spencer her proportionate interest in the Times-Picayune Publishing Company. That interest, formerly represented by 20 shares is now represented by 40 shares. Succession of Quintero, (La. 1946) 24 S. ( 2d) 589

Heterogeneous Distributed Data Base Management Systems

This work analyzes the design and implementation issues of Heterogeneous Distributed Data Base Management Systems (HDDBMS). To date, HD-DBMS research projects and implementa tions have been limited. The few such systems which have been constructed provide valuable insight into the nature of problems faced due to heterogeneity. Some of these systems (SIRIUS-DELTA, MULTIBASE, AIDA) , are presented in order to examine their solutions to the problems. The major issues described in the thesis are: the architec ture of the distributed system; query translation; schema mapping; and integration of the schemata within the hetero geneous distributed database, in seeking solutions to these issues, an architecture for a HD-DBMS is proposed

A simulator study for the development and evaluation of operating procedures on a supersonic cruise research transport to minimize airport-community noise

Piloted-simulator studies were conducted to determine takeoff and landing operating procedures for a supersonic cruise research transport concept that result in predicted noise levels which meet current Federal Aviation Administration (FAA) certification standards. With the use of standard FAA noise certification test procedures, the subject simulated aircraft did not meet the FAA traded-noise-level standards during takeoff and landing. However, with the use of advanced procedures, this aircraft meets the traded-noise-level standards for flight crews with average skills. The advanced takeoff procedures developed involved violating some of the current Federal Aviation Regulations (FAR), but it was not necessary to violate any FAR noise-test conditions during landing approach. Noise contours were also determined for some of the simulated takeoffs and landings in order to indicate the noise-reduction advantages of using operational procedures other than standard

Accretion from debris disks onto white dwarfs : Fingering (thermohaline) instability and derived accretion rates

Recent observations of a large number of DA and DB white dwarfs show evidence of debris disks, which are the remnants of old planetary systems. The infrared excess detected with \emph{Spitzer} and the lines of heavy elements observed in their atmospheres with high-resolution spectroscopy converge on the idea that planetary material accretes onto these stars. Accretion rates have been derived by several authors with the assumption of a steady state between accretion and gravitational settling. The results are unrealistically different for DA and DB white dwarfs. When heavy matter is accreted onto stars, it induces an inverse $\mu$-gradient that leads to fingering (thermohaline) convection. The aim of this letter is to study the impact of this specific process on the derived accretion rates in white dwarfs and on the difference between DA and DB. We solve the diffusion equation for the accreted heavy elements with a time-dependent method. The models we use have been obtained both with the IRAP code, which computes static models, and the La Plata code, which computes evolutionary sequences. Computations with pure gravitational settling are compared with computations that include fingering convection. The most important result is that fingering convection has very important effects on DAs but is inefficient in DBs. When only gravitational settling is taken into account, the time-dependent computations lead to a steady state, as postulated by previous authors. When fingering convection is added, this steady state occurs much later. The surprising difference found in the past for the accretion rates derived for DA and DB white dwarfs disappears. The derived accretion rates for DAs are increased when fingering convection is taken into account, whereas those for DBs are not modified. More precise and developed results will be given in a forthcoming paper

PRINCIPAL AND AGENT-COMPENSATION OF UNFAITHFUL AGENT

Plaintiff, manager of defendant\u27s mechanical division under a contract requiring him to devote all his efforts to this employment and providing that he would share the profits and losses of the division equally with defendant as his only compensation, sued to recover a balance of $42,991.90 in his favor after his discharge by defendant. The contract provided that on any termination of plaintiff\u27s employment his account should be adjusted and any credit balance paid him, but defendant contended that plaintiff had forfeited his right to compensation by secretly engaging in a partnership in competition with defendant. The trial court found that defendant was not substantially harmed by this activity but dismissed plaintiff\u27s bill for an accounting. On appeal, held, reversed. The infidelity of plaintiff as an agent should not, as between him and his principal, entail consequences in the matter of compensation which his principal has agreed should not follow from it, although plaintiff will be charged with the entire$1,630.74 profit of his secret occupation and, in addition, any damages defendant may be able to prove at the second trial. Walsh v. Atlantic Research Associates, Inc., (Mass. 1947) 71 N.E. (2d) 580

CORPORATIONS-FOREIGN CORPORATIONS-JURISDICTION IN DERIVATIVE SUITS

As an aftermath of the much publicized circus fire in Hartford, Connecticut, on July 6, 1944, owners of 37 per cent of the stock of the circus corporation brought a derivative action against the officers and directors alleging failure to observe proper precautions and asking that the corporation be indemnified for losses sustained and for an accounting for certain corporation funds spent for the benefit of one of the- defendant directors. The suit was instituted in New York where the corporation was licensed to do business although the circus was incorporated in Delaware, wintered in Florida, and the cause of action arose in Connecticut. Defendants moved to dismiss on the ground, inter alia, that New York ought not to assume jurisdiction because of the doctrine of forum non conveniens. Held, motion denied; derivative stockholders\u27 actions can be properly brought in a state other than that of the corporation\u27s domicile. The court recognized the general rule, grounded on considerations of public policy, convenience and expediency that courts decline jurisdiction of a suit to interfere with or control the internal affairs of a foreign corporation, but decided that the instant suit did not involve such attempted interference or control. North v. Ringling, (N.Y. 1946) 63 N.Y.S. (2d) 135

TORTS-LIABILITY OF RESCUED DEFENDANT WHO CARELESSLY EXPOSES HIMSELF TO DANGER TO RESCUING PLAINTIFF WHO IS INJURED

While visiting defendant\u27s farm, plaintiff was injured pushing defendant from the path of her own automobile which she had stopped on an incline without setting the brake. Held, for plaintiff. Lack of self-protective care may be negligence toward any person in whose vicinity one exposes oneself to undue risk of injury. Carney v. Buyea, 271 App. Div. 338, 65 N.Y.S. (2d) 902 (1946)