Southern Columns v.38-1 1986

Features the article Eminent Author Chaim Potok To Speak . Best-selling American novelist Chaim Potok will be visiting the campus March 19 and 20 as a part of the President\u27s Lecture Series.https://knowledge.e.southern.edu/alumni_newsletter/1108/thumbnail.jp

Naomi, I Moan

In this quiz the answer to each clue is a palindrome; to aid in the solution, word-divisions and all vowels are given. The first letters of all thirteen palindromes will spell out another palindrome when read from top to bottom. Answers are given in Answers and Solutions at the end of the issue

A-CHAIM: Near-Real-Time Data Assimilation of the High Latitude Ionosphere With a Particle Filter

The Assimilative Canadian High Arctic Ionospheric Model (A-CHAIM) is an operational ionospheric data assimilation model that provides a 3D representation of the high latitude ionosphere in Near-Real-Time (NRT). A-CHAIM uses low-latency observations of slant Total Electron Content (sTEC) from ground-based Global Navigation Satellite System (GNSS) receivers, ionosondes, and vertical TEC from the JASON-3 altimeter satellite to produce an updated electron density model above 45° geomagnetic latitude. A-CHAIM is the first operational use of a particle filter data assimilation for space environment modeling, to account for the nonlinear nature of sTEC observations. The large number (>104 ) of simultaneous observations creates significant problems with particle weight degeneracy, which is addressed by combining measurements to form new composite observables. The performance of A-CHAIM is assessed by comparing the model outputs to unassimilated ionosonde observations, as well as to in-situ electron density observations from the SWARM and DMSP satellites. During moderately disturbed conditions from 21 September 2021 through 29 September 2021, A-CHAIM demonstrates a 40%–50% reduction in error relative to the background model in the F2-layer critical frequency (foF2) at midlatitude and auroral reference stations, and little change at higher latitudes. The height of the F2-layer (hmF2) shows a small 5%–15% improvement at all latitudes. In the topside, A-CHAIM demonstrates a 15%–20% reduction in error for the Swarm satellites, and a 23%–28% reduction in error for the DMSP satellites. The reduction in error is distributed evenly over the assimilation region, including in data-sparse regions

Densification and preservation of ceramic nanocrystalline character by spark plasma sintering

Spark plasma sintering is a hot pressing technique where rapid heating by dc electric pulses is used simultaneously with applied pressure. Thus, spark plasma sintering is highly suitable for rapid densification of ceramic nanoparticles and preservation of the final nanostructure. A considerable portion of the shrinkage during densification of the green compact of nanoparticles in the first and intermediate stages of sintering occurs during heating by particle rearrangement by sliding and rotation. Further densification to the final stage of sintering takes place by either plastic yield or diffusional processes. Full densification in the final stage of sintering is associated with diffusional processes only. Nanoparticle sliding and rotation during heating may also lead to grain coalescence, with much faster kinetics than normal grain growth at higher temperatures. Based on existing models for particle rearrangement and sliding, the contributions of these processes in conjunction with nanoparticle properties and process parameters were highlighted

Optically transparent ceramics by spark plasma sintering of oxide nanoparticles

Optical transparency in polycrystalline ceramic oxides can be achieved if the material is fully densified. Spark plasma sintering (SPS) of oxide nanoparticles leads to immediate densification with final-stage sintering. Further densification by annihilation of the isolated pores is associated with diffusional processes, regardless of the densification mechanism during the intermediate stage. Densification equations in conjunction with the concept of grain boundary free volume were used to derive the pore size–grain size–temperature map for designing the nanopowder and SPS process parameters to obtain transparent oxides

Gallium Arsenide Monolithic Optoelectronic Circuits

The optical properties of GaAs make it a very useful material for the fabrication of optical emitters and detectors. GaAs also possesses electronic properties which allow the fabrication of high speed electronic devices which are superior to conventional silicon devices. Monolithic optoelectronic circuits are formed by the integration of optical and electronic devices on a single GaAs substrate. Integration of many devices is most easily accomplished on a semi-insulating (SI) sub-strate. Several laser structures have been fabricated on SI GaAs substrates. Some of these lasers have been integrated with Gunn diodes and with metal semiconductor field effect transistors (MESFETs). An integrated optical repeater has been demonstrated in which MESFETs are used for optical detection and electronic amplification, and a laser is used to regenerate the optical signal. Monolithic optoelectronic circuits have also been constructed on conducting substrates. A heterojunction bipolar transistor driver has been integrated with a laser on an n-type GaAs substrate

America Abandoned: German-Jewish Visions of American Poverty in Serialized Novels by Joseph Roth, Sholem Asch, and Michael Gold

In 1930, Hungarian- born Jewish author Arthur Holitscher’s book Wiedersehn mit Amerika: Die Verwandlung der U.S.A. (Reunion with America: The Trans-formation of the U.S.A.) was reviewed by one J. Raphael in the German- Jewish Orthodox weekly newspaper, Der Israelit. This reviewer concluded: “Despite its good reputation, America is a strange country. And Holitscher, whose relationship to Judaism is not explicit, but direct, has determined that to be the case for American Jews as well.” The reviewer’s use of the word “strange” (komisch) offers powerful insight into the complex perceptions of America held by many German- speaking Jews, which in 1930 were at best mixed and ambivalent. An earlier travel book by Arthur Holitscher (1869– 1941) from 1912 depicts America more favorably, though it is widely believed to have provided inspiration for Franz Kafka’s unfinished novel, Amerika: Der Verschollene (Amerika or The Man who Disappeared, published posthumously in 1927), which famously opens with a description of the Statue of Liberty holding aloft a sword rather than a torch. [excerpt