Monitoring the Employment Contract in Alaska

Detta arbete handlar om bakomliggande faktorer för framgångsrik kompetensutveckling av lärare inom naturvetenskap. Det är en litteraturstudie av tidigare forskning inom området. Syftet med studien är att kritiskt granska vad tidigare studier belyser som viktiga faktorer vid framgångsrik kompetensutveckling och sammanställa dem för att visa på överlappningar och särskiljande drag mellan dem. Metoden som använts är sammanställning samt analys av tidigare publicerad forskning i relation till skollag och övrig relevant litteratur inom området.   Resultaten visar på sex olika framgångsrika metoder för kompetensutveckling av lärare inom naturvetenskap. Genom en vidare analys framträder fem faktorer som verkar för att de sex metoderna ger framgångsrik kompetensutveckling. Dessa är, utan inbördes ordning: Deltagarnas inställning, antal timmar avsatta för kompetensutveckling, möjlighet till reflektion, möjlighet till kollegialt lärande samt anpassning efter faktiska behov. Resultaten diskuteras sedan ur ett kritiskt perspektiv i relation till ämnet, det ges även förslag till vidare forskning inom området. Studiens slutsats är att huruvida kompetensutveckling blir framgångsrik till stor del beror på i vilken mån de fem faktorerna uppfyllts. Av dessa fem är reflektion den faktor som har störst påverkan, men det återstår att undersöka reflektionens inre liv och de olika processer som uppstår

A fully-integrated 1.8-V, 2.8-W, 1.9-GHz, CMOS power amplifier

This paper demonstrated the first 2-stage, 2.8W, 1.8V, 1.9GHz fully-integrated DAT power amplifier with 50Ω input and output matching using 0.18μm CMOS transistors. It has a small-signal gain of 27dB. The amplifier provides 2.8W of power into a 50Ω load with a PAE of 50%

Simultaneous ion sputter polishing and deposition

Results of experiments to study ion beam sputter polishing in conjunction with simultaneous deposition as a mean of polishing copper surfaces are presented. Two types of simultaneous ion sputter polishing and deposition were used in these experiments. The first type utilized sputter polishing simultaneous with vapor deposition, and the second type utilized sputter polishing simultaneous with sputter deposition. The etch and deposition rates of both techniques were studied, as well as the surface morphology and surface roughness

Planar sandwich antennas for submillimeter applications

A planar receiving antenna with a predictable pattern at submillimeter wavelength is demonstrated experimentally for the first time. It is single lobed and efficient, with a gain of approximately 8 dB at a wavelength of 119 µm

Chandra Observations of 1RXS J141256.0+792204 (Calvera)

We report the results of a 30 ks Chandra ACIS-S observation of the isolated compact object 1RXS J141256.0+792204 (Calvera). The X-ray spectrum is adequately described by an absorbed neutron star hydrogen atmosphere model with an effective temperature at infinity of 88.3 +/- 0.8 eV and radiation radius at infinity of 4.1 +/- 0.1 km/kpc. The best-fit blackbody spectrum yields parameters consistent with previous measurements; although the fit itself is not statistically acceptable, systematic uncertainties in the pile-up correction may contribute to this. We find marginal evidence for narrow spectral features in the X-ray spectrum between 0.3 and 1.0 keV. In one interpretation, we find evidence at 81%-confidence for an absorption edge at 0.64 (+0.08) (-0.06) keV with an equivalent width of ~70 eV; if this feature is real, it is reminiscent of features seen in the isolated neutron stars RX J1605.3+3249, RX J0720.4-3125, and 1RXS J130848.6+212708 (RBS 1223). In an alternative approach, we find evidence at 88%-confidence for an unresolved emission line at energy 0.53 +/- 0.02 keV, with an equivalent width of ~28 eV; the interpretation of this feature, if real, is uncertain. We search for coherent pulsations up to the Nyquist frequency of 1.13 Hz and set an upper limit of 8.0% rms on the strength of any such modulation. We derive an improved position for the source and set the most rigorous limits to-date on any associated extended emission on arcsecond scales. Our analysis confirms the basic picture of Calvera as the first isolated compact object in the ROSAT/Bright Source Catalog discovered in six years, the hottest such object known, and an intriguing target for multiwavelength study.Comment: Submitted to ApJ. AASTeX, 19 pages, 2 figure

Paper Session II-B - NLS Cost Containment

Growth in costs and schedules of aerospace projects is all too commonplace. Within NASA, about 70% of cost growth is attributed to underestimation of technical difficulty, 20% to major scope changes and 10% to external impacts. Schedule duration has increased by 50% over the last 15 years. Most growth problems can be traced to incomplete Phase A/B requirements definition, coupled with the resulting incomplete cost estimates. NLS must be a cost effective, low cost transportation system to be viable. To achieve this goal a cost containment system is required which forces cost, technical and schedule to function together interlocked in a controlled management system

Gamma-Ray Bursts and the Cosmic Star Formation Rate

We have tested several models of GRB luminosity and redshift distribution functions for compatibility with the BATSE 4B number versus peak flux relation. Our results disagree with recent claims that current GRB observations can be used to strongly constrain the cosmic star formation history. Instead, we find that relaxing the assumption that GRBs are standard candles renders a very broad range of models consistent with the BATSE number-flux relation. We explicitly construct two sample distributions, one tracing the star formation history and one with a constant comoving density. We show that both distributions are compatible with the observed fluxes and redshifts of the bursts GRB970508, GRB971214, and GRB980703, and we discuss the measurements required to distinguish the two models.Comment: 12 pages, 2 postscript figures, uses AAS LaTex macros v4.0. To be published in Astrophysical Journal Letters, accepted August 20, 1998. Revised for publicatio