Strain-age cracking in Rene 41 alloy

Weldability test determines the effects of material and process variables on the occurrence of strain-age cracking, and demonstrates effective and practical means for its reduction. Studies consist of tensile, impact, and stress-rupture tests

A Far-Infrared Survey of Molecular Cloud Cores

We present a catalogue of molecular cloud cores drawn from high latitude, medium opacity clouds, using the all-sky IRAS Sky Survey Atlas (ISSA) images at 60 and 100~$\mu$m. The typical column densities of the cores are $N(H_2)\sim 3.8 \times 10^{21}$cm$^{-2}$ and the typical volume densities are $n(H_2) \sim 2 \times 10^3$cm$^{-3}$. They are therefore significantly less dense than many other samples obtained in other ways. Those cloud cores with IRAS point sources are seen to be already forming stars, but this is found to be only a small fraction of the total number of cores. The fraction of the cores in the protostellar stage is used to estimate the prestellar timescale - the time until the formation of a hydrostatically supported protostellar object. We argue, on the basis of a comparison with other samples, that a trend exists for the prestellar lifetime of a cloud core to decrease with the mean column density and number density of the core. We compare this with model predictions and show that the data are consistent with star formation regulated by the ionisation fraction.Comment: 13 pages, 7 figure

Transition from glass to graphite in manufacture of composite aircraft structure

The transition from fiberglass reinforced plastic composites to graphite reinforced plastic composites is described. Structural fiberglass design and manufacturing background are summarized. How this experience provides a technology base for moving into graphite composite secondary structure and then to composite primary structure is considered. The technical requirements that must be fulfilled in the transition from glass to graphite composite structure are also included

Predicting Smoking Behaviors Among Junior High School Students in Ghana

Despite the rising rate of smoking in sub-Sahara African countries, measures to control the tobacco epidemic have been limited to developed countries. The purpose of the present study was to recommend predictive models for determining predictors of smoking tendencies among junior high school students in Ghana. The 2009 Global Youth Tobacco Survey (GYTS) served as the data source. The GYTS is a school-based survey designed to enhance the ability of countries to monitor tobacco use among youth and to guide the implementation and evaluation of tobacco control and prevention programs. Logit model and forward selection were used to choose predictive variables for smoking tendencies and behaviors. Receiver Operating Characteristic (ROC) curve, Area under the curve (AUC) and C-Index were validation tools used to assess the predictive power of recommended models. Results showed promising potential for different predictive models: where students smoked, having friends who smoked, having people smoke in their presence, chewing tobacco products, and a student's sex significantly predicted their smoking tendencies

Does PAL work? An exploration of affect amongst First-year HE in FE students

The study evaluates a peer-assisted learning (PAL) scheme as an effective strategy in alleviating levels of negative emotions and, in the process, contributes to explorations of affect in first-year students in an HE in FE environment, with a particular focus on anxiety and related emotions. Various types of anxieties are defined in the context of a student’s experience in HE, followed by an explanation of the present interventional study in an HE in FE institution, including the survey method used to collect data analyzed through SPSS. Surprisingly, the main findings are that overall anxiety and worry increased for students belonging to most faculties with time, regardless of participation in the PAL scheme. A positive finding was nonetheless that anxiety levels increased more steadily for students who belonged to the control group. The PAL scheme may have thus influenced how less anxious PAL students felt, compared to those who did not participate in the PAL scheme who were left feeling more anxious at the end of the semester

An interactive method for digitizing zone maps

A method is presented for digitizing maps that consist of zones, such as contour or climatic zone maps. A color-coded map is prepared by any convenient process. The map is then read into memory of an Image 100 computer by means of its table scanner, using colored filters. Zones are separated and stored in themes, using standard classification procedures. Thematic data are written on magnetic tape and these data, appropriately coded, are combined to make a digitized image on tape. Step-by-step procedures are given for digitization of crop moisture index maps with this procedure. In addition, a complete example of the digitization of a climatic zone map is given

Irrelevant Exceptional Divisors for Curves on a Smooth Surface

Given a singular curve on a smooth surface, we determine which exceptional divisors on the minimal resolution of that curve contribute toward its jumping numbers.Comment: Added reference to Favre & Jonsson and a slight extension of the comment immediately following Definition 2.