Effective Comprehension Strategies in the Social Studies Classroom

This study investigates effective comprehension strategies to apply within a social studies classroom. Effective comprehension strategies applied to social studies curriculum will help prepare students to be successful citizens in the ever changing world around us. In conducting this research, I looked at four comprehension strategies and the potential impact they have in a social studies classroom. The four comprehension strategies are: Sumarization, Vocabulary Development, Compare and Contrast, and Guided Reading

Salmonella and tomatoes

Outbreak information linking fresh tomato fruit to illnesses is reviewed in this chapter. While tomato fruit appear to support substantial proliferation of certain serovars of Salmonella enterica, detection of this pathogen in tomato plants prior to harvest is rare, and reports of Salmonella existence in tomato fruit still attached to field-grown plants are virtually non-existent. The bacterium is sensitive to UV and can be outcompeted by the native phytomicrobiota, which may explain its absence in field-grown crops. However, the persistence of certain serovars in fields and ponds of certain production areas is noted. Together with evidence of bacteria becoming internalized in tomato fruit during crop development likely through natural apertures, the presence of S. enterica in and around production fields suggests that an unusual weather event could lead to Salmonella contamination of fruit prior to harvest. The bacterium appears physiologically adaptive toward proliferation in tomato fruit. Once inside tomatoes, Salmonella is capable of sensing the availability of nutrients and physiological state of the fruit and differentially regulates specific genes. However, because Salmonella is an efficient nutrient scavenger, removal of multiple metabolic and regulatory genes was required to reduce its fitness within the fruit. Plants do not appear to recognize human enterics as pathogens, and their defenses treat them as endophytes

Characterizing the Rigidly Rotating Magnetosphere Stars HD 345439 and HD 23478

The SDSS III APOGEE survey recently identified two new $\sigma$ Ori E type candidates, HD 345439 and HD 23478, which are a rare subset of rapidly rotating massive stars whose large (kGauss) magnetic fields confine circumstellar material around these systems. Our analysis of multi-epoch photometric observations of HD 345439 from the KELT, SuperWASP, and ASAS surveys reveals the presence of a $\sim$0.7701 day period in each dataset, suggesting the system is amongst the faster known $\sigma$ Ori E analogs. We also see clear evidence that the strength of H-alpha, H I Brackett series lines, and He I lines also vary on a $\sim$0.7701 day period from our analysis of multi-epoch, multi-wavelength spectroscopic monitoring of the system from the APO 3.5m telescope. We trace the evolution of select emission line profiles in the system, and observe coherent line profile variability in both optical and infrared H I lines, as expected for rigidly rotating magnetosphere stars. We also analyze the evolution of the H I Br-11 line strength and line profile in multi-epoch observations of HD 23478 from the SDSS-III APOGEE instrument. The observed periodic behavior is consistent with that recently reported by Sikora and collaborators in optical spectra.Comment: Accepted in ApJ

KELT-22Ab: A Massive, Short-Period Hot Jupiter Transiting a Near-solar Twin

We present the discovery of KELT-22Ab, a hot Jupiter from the KELT-South survey. KELT-22Ab transits the moderately bright (V∼11.1) Sun-like G2V star TYC 7518-468-1. The planet has an orbital period of P = 1.3866529±0.0000027 days, a radius of R_P = 1.285^(+0.12)_(−0.071) R_J, and a relatively large mass of M_P = 3.47^(+0.15)_(−0.14) M_J. The star has R⋆ = 1.099^(+0.079)_(−0.046) R⊙, M⋆ = 1.092^(+0.045)_(−0.041) M⊙, T_(eff) = 5767^(+50)_(−49) K, log g⋆ = 4.393^(+0.039)_(−0.060) (cgs), and [m/H] = +0.259^(+0.085)_(−0.083), and thus, other than its slightly super-solar metallicity, appears to be a near solar twin. Surprisingly, KELT-22A exhibits kinematics and a Galactic orbit that are somewhat atypical for thin disk stars. Nevertheless, the star is rotating quite rapidly for its estimated age, shows evidence of chromospheric activity, and is somewhat metal rich. Imaging reveals a slightly fainter companion to KELT-22A that is likely bound, with a projected separation of 6” (∼1400 AU). In addition to the orbital motion caused by the transiting planet, we detect a possible linear trend in the radial velocity of KELT-22A suggesting the presence of another relatively nearby body that is perhaps non-stellar. KELT-22Ab is highly irradiated (as a consequence of the small semi-major axis of a/R⋆ = 4.97), and is mildly inflated. At such small separations, tidal forces become significant. The configuration of this system is optimal for measuring the rate of tidal dissipation within the host star. Our models predict that, due to tidal forces, the semi-major axis of KELT-22Ab is decreasing rapidly, and is thus predicted to spiral into the star within the next Gyr

PVD TBC experience on GE aircraft engines

The higher performance levels of modern gas turbine engines present significant challenges in the reliability of materials in the turbine. The increased engine temperatures required to achieve the higher performance levels reduce the strength of the materials used in the turbine sections of the engine. Various forms of Thermal Barrier Coatings (TBC's) have been used for many years to increase the reliability of gas turbine engine components. Recent experience with the Physical Vapor Deposition (PVD) process using ceramic material has demonstrated success in extending the service life of turbine blades and nozzles. Engine test results of turbine components with a 125 micrometer (0.005 in) PVD TBC have demonstrated component operating temperatures of 56-83 C (100-150 F) lower than uncoated components. Engine testing has also revealed the TBC is susceptible to high angle particle impact damage. Sand particles and other engine debris impact the TBC surface at the leading edge of airfoils and fracture the PVD columns. As the impacting continues the TBC erodes away in local areas. Analysis of the eroded areas has shown a slight increase in temperature over a fully coated area, however, a significant temperature reduction was realized over an airfoil without any TBC