Space shuttle orbiter auxiliary power unit development challenges

When the flying spacecraft was approved for development, a power unit for the hydraulic system had to be developed. Unlike other systems on the orbiter, there was no precedent in earlier spacecraft for a hydraulic system nor for the power unit to drive the hydraulic pumps. The only prototypes available were airplane auxiliary power units (APU), which were not required to operate in the severe environments of a spacecraft nor to have the longevity of an orbiter hydraulic power unit. The challenge was to build a hydraulic power unit which could operate in 0g or 3g, in a vacuum or at sea level pressure, and at -65 F or 225 F, which would be capable of restarting while hot, and which would be capable of sustaining the hydraulic loads for the life of the orbiter. The basic approach to providing hydraulic power for the orbiter was to use a small, high speed, monopropellant fueled turbine power unit to drive a conventional aircraft type hydraulic pump. The stringent requirements imposed on the orbiter APU quickly made this machine different from existing aircraft APUs

Communication

Section on "Communication" from Encyclopedia of Applied Animal Behaviour and Welfar

Implementing Content Literacy and Disciplinary Literacy: A Mixed Methods Study of Middle School Teachers\u27 Pedagogical Dispositions

Researchers uphold that teachers\u27 beliefs toward reading influence their planning and implementation, and that content area teachers are often reluctant to implement literacy strategies and skills within their instruction (Ness, 2009; Nourie & Lenski, 1998; Richardson et al., 1991). Much of this reluctance stems from teachers’ lack of familiarity with content area and disciplinary literacy or misconceptions surrounding instruction that supports literacy implementation (O’Byrne et al., 2020). However, within the field of literacy, there are tensions between the implementation of content area versus disciplinary literacy (Graham et al., 2017). The purpose of this study was to examine middle school content area teachers\u27 pedagogical dispositions toward implementing content area literacy and disciplinary literacy strategies and skills into their instruction. This study utilized a two-phase explanatory sequential mixed method design (quan → QUAL) based on a theoretical framework consisting of social constructivist theory, metacognitive theory, and social cognitive theory. Within Phase I of the study, I utilized a survey to collect quantitative data about participants’ self-efficacy beliefs (n=26). During Phase II, I collected qualitative data from a smaller group of participants (n=4) using semi-structured interviews and artifact collection. Utilizing a case study design, I explored participants’ responses regarding their literacy implementation and their professional experiences and training (Yin & Campbell, 2018). Through this study, I found discrepancies surrounding teachers’ abilities to differentiate between content area and disciplinary literacy approaches, indicating that teachers could benefit from additional opportunities to develop their knowledge of literacy instruction

The sources of Hiawatha

Thesis (M.A.)--Boston University, 1913. This item was digitized by the Internet Archive

Management of Cutaneous Malignancy - A Review

Skin cancer is the most frequent type of cancer, accounting for about 20% of all cancers in the State of Virginia, and the most common type of skin cancer is the basal cell carcinoma. The basal cell carcinoma is a tumor which is not considered highly malignant because, in general, it does not metastasize, although there have been a few instances in which metastases have occurred. However, such lesions may be quite destructive at times. The typical basal cell carcinoma presents as a waxy, papular or nodular lesion which has a gelatinous or somewhat translucent appearance. Coursing across the surface from the normal skin toward the center of the lesion, one will often see fine telangiectatic vessels. At times the lesions may be somewhat deceptive because of their location, and this is particularly true in the inner canthus where they may be missed until they are fairly large. Some basal cell carcinomas will remain relatively quiescent for long periods of time; others will become much more aggressive and grow rapidly. The tumor may, at times, be much like an iceberg with only the tip appearing, and this is particularly a problem with lesions on the nose. In treating a lesion in this location one has to be very cautious and be prepared to perform grafting, if this is required. It may, at times, be difficult to differentiate a basal cell carcinoma from small lesions which we call sebaceous adenomas, which occur frequently on the faces of elderly individuals. These are small waxy, creamy elevations usually on the forehead and they are the result of hyperplasia of sebaceous follicles

Mars exploration program

An overview of the Mars Exploration Program is presented in outline and graphic form. Mission objectives, mission strategy, operations concept, transportation element, launch vehicle considerations and program schedule are addressed

THE 12-WEEK EFFECT OF CHANGE ON BODY WEIGHT AND BODY COMPOSITION ON MUSCULAR STRENGTH AND FUNCTION IN OVERWEIGHT ADULTS

CHANGE IN BODY WEIGHT AND BODY COMPOSITION ON MUSCULAR STRENGTH AND FUNCTION IN OVERWEIGHT ADULTSK.A. Weary, K.M. Polzien, A.D. Otto, J.M. Jakicic, FACSM. Physical Activity and Weight Management Research Center, Department of Health and Physical Activity. University of Pittsburgh, Pittsburgh, PA 15261PURPOSE: The purpose of this study is to examine the relationship between the changes in body weight and lean body mass with changes in muscular strength and function in overweight and obese adults before and after a 12 week weight loss intervention. METHODS: Fifty-seven overweight adults (age = 41.3 + .87 years; BMI = 33.1 + 2.8 kg/m2; % body fat = 42.4 + 3.8 %) participated in this study. Forty eight subjects completed the 12 week weight loss intervention consisting of behavioral counseling. Subjects were instructed to reduce energy intake to 1200 to 1500 kcal/d and to increase exercise to 30 to 40 min/d on 5 d/wk. Participants completed assessments of body weight, body composition using the BIA method, muscular strength (1-RM chest press, 1-RM leg extension, grip strength), and physical function (sit-to-stand) at baseline and following the 12-week intervention. RESULTS: Paired sample T-tests revealed a significant decrease in body weight, lean body mass, 1-RM chest press, and 1-RM leg extension (p<0.05), with no significant change in grip strength from baseline to 12-weeks (see Table 1). However there was a significant increase in physical function (sit-to-stand score) from baseline to 12-weeks (p<0.05) (Table 1), with the significant relation observed for percent change in body weight and the change in physical function (r = 0.35; p<0.05).Table 1. Baseline12 WeeksChangep-valueWeight (kg)88.4 + 9.183.2 + 9.65.2 + 3.4<0.001*LBM (kg)50.9 + 4.950.1 + 4.70.8 + 1.70.002*1-RM chest (kg)27.65 + 6.725.35 + 6.42.3 + 4.20.003*1-RM leg (kg)35.9 + 11.830.9 + 10.14.9 + 11.4<0.001*Grip Strength (kg)32.1 + 6.331.6 + 6.60.5 + 6.4 0.36Sit-to-Stand14.5 + 3.415.6 + 4.61.1 + 3.80.05** Indicates significance at p<0.05CONCLUSION: The observed reduction in body weight was associated with a concurrent reduction in LBM and muscular strength. However, these reductions did not negatively impact physical function, but rather were accompanied by an increase in physical function. This increase in physical function may impact quality of life, and demonstrates the additional benefits of promoting weight loss in overweight and obese adults