Thursday, January 30, 2020

Astronomy Study Guide Essay Example for Free

Astronomy Study Guide Essay xix. All jovian planets have strong winds and storms 2. Be able to describe the different stages in stellar evolution and which star will end their lives in which ways. Included in this is the maximum masses of stars that will become white dwarfs, neutron stars, and black holes and the maximum masses of white dwarfs and neutron stars. e. Step 1- Becoming a Star xx. As a cloud collapses, the center becomes very, very hot and very dense f. Step 2- Fusion xxi. As the gas cloud collapses, the core becomes hotter and the density inside the core increases xxii. Eventually, the temperature and density reach a point where nuclear fusion can occur g. Step 3- Balance: all main sequence stars are in hydrostatic equilibrium xxiii. Fusion provides radiation that creates an outward pressure h. Protostar to Main Sequence xxiv. A protostar contracts and heats until the core temperature is sufficient for hydrogen fusion i. Upper Limit on a Star’s Mass 3. Understand everythi9ng about the HR diagram and how it can be used j. Identifies a definite relationship between temperature and absolute magnitude k. The smallest stars are the tiny white dwarfs and are found in the lower left corner of the diagram l. Main sequence stars span a range of sizes from the small found in the lower right and the large found in the upper left m. Largest stars are the giant and supergiant stars which are sound in the upper right corner n. Most stars fall somewhere on the main sequence o. Diagram Depicts xxv. Temperature xxvi. Color xxvii. Spectral Type xxviii. Luminosity xxix. Radius 4. Be able to describe the Doppler effect and indicate which stars are shifts the most from looking at the spectra of stars and from looking at the wavelength of peak radiation. p. The Doppler effect is able to determine the movement of objects in space. It can tell if the object is moving toward or away from earth. 5. What are the different types of galaxies and what are the different types and ages of stars that you would expect to observe in each q. Spiral xxx. Disk- stars of all ages, and many gas clouds xxxi. Bulge- old stars, few gas clouds xxxii. Halo- old stars, few gas clouds 1. Blue-White color indicates ongoing star formation 2. Red-Yellow color indicates older star population xxxiii. Barred Spiral Galaxy- has a bar of stars across the bulge xxxiv. Centicular Galaxy- has a disk like a spiral but much less dusty gas(intermediate between spiral and elliptical) r. Elliptical xxxv. All spherical components, virtually no disk component 3. Red-Yellow color indicates older star population s. Irregular xxxvi. Neither spiral nor elliptical 4. Blue-White indicates ongoing star formation 5. All tend to be really far away t. *Spiral galaxies are often found in groups 6. Use energy output vs. wavelength graphs to determine the size temperature and color of various stars. 7. Be able to choose the most cost effective option from a list of possible research telescopes u. Three Types of Telescopes xxxvii. Refracting Telescope-uses a glass lens to concentrate incoming light xxxviii. Reflecting Telescope-uses mirrors to concentrate incoming star light (most researching telescopes today are reflecting) xxxix. Radio Telescopes- sends radio waves into space 8. Give a general description of Big Bang theory and the evidence for it. v. In the 1940’s based on Hubble’s law, George Gamon proposed that the universe began in a colossal explosion w. In the 1950’s, the term Big Bang was coined be an unconvinced Sir Fred Hoyce x. Evidence for Big Bang xl. We have detected the background radiation from the Big Bang xli. Correctly predicts the abundance of helium and other light elements in universe xlii. The cosmic microwave background=the radiation leftover from the Big Bang xliii. Patterns of structure observed by WMAP show the â€Å"seeds† of the universe xliv. Abundance of elements give us clues as well 9. How does the force of gravity between two objects depend on mass and distance. y. Newton’s Law of Gravitation xlv. Two objects attract each other with a force that is directly proportional to the product of their own masses and is inversely proportional to the square of the distance z. Universal Law of Gravitation xlvi. Every mass attracts every other mass xlvii. Attraction is directly proportional to the masses xlviii. Attractions is inversely proportional to the square of the distance between their centers xlix. F=G(m1m2/d2) 10. What provides energy to stars at different points during their lifetime (proto-star, main sequence, red giant, etc†¦) 11. What can we know from the spectrum of a star {. We can determine whether the star is moving toward us or moving away from us. |. We can’t determine the exact speed of the star but we can determine whether it is moving fast or slow toward us and if it is moving fast or slow away from us 12. What is a Cepheid variable? }. Light curve shows that its brightness alternately rises and falls over a period of 50 days ~. With longer periods have higher luminosities 13. What does Hubble’s law say? . Velocity=H0 x distance 14. Compare the sizes of different objects in the solar system, in the galaxy, and in the universe. . The Sun is the largest object in the solar system . Earth VenusMarsMercurymoon 15. Compare the scales (relative distances) to various locations in the solar system, the galaxy, and the universe 16. What makes something science? How do you tell if something is a scientific theory, a hypotheses, or something else? . What is Science l. Seeks to understand the rules and laws of nature li. Uses systematic observations lii. Uses mathematical models liii. Experimentally tests ideas . A Scientific Theory must: liv. Explain a wide variety of observations with a few simple principles lv. Be supportive be a large compelling body of evidence lvi. Not have failed any crucial tests of its validity 17. List properties of thermal radiation. . Hotter objects emit more light at all frequencies . Hotter objects emit photons with a higher average energy . Nearly all large or dense objects emit thermal radiation including stars, planets, and you . An objects thermal radiation spectrum depends only on temperature 18. How do we know our position in the solar system, in the galaxy, and the universe? . Kepler’s Law lvii. Using Kepler’s law we are able to calculate the orbital speed of objects and compare them. lviii. To compare our location to the galactic center we use the Kepler’s Law Rotation curve, which plots an objects orbital speed against the distance from the galactic center. 19. Understand the phases of the moon. Be able to choose relative positions of the Earth, moon, and sun to produce a given moon phase. . 1st quarter . Waxing gibbous . Full moon . Waning gibbous . 3rd quarter . Waning crescent . New moon . Waxing crescent 20. Understand the major motions in the sky- over the course of a day, over the course of man y weeks/months, and over the course of years. 21. What causes seasons? . Earth’s axis points in the same direction all year, so its orientation relative to the sun changes as Earth orbits the sun . Summer occurs in your hemisphere when sunlight hits it more directly, winter occurs when sunlight hits it less directly . Axis tilt is the key to seasons without it we wouldn’t have seasons 22. Apparent and absolute magnitudes, what they tell us, and how they are used to determine distances. . Apparent Magnitude- how bright the object appears to us on earth . Absolute Magnitude- how bright it actually is lix. Negative means brighter lx. Positive means dimmer . By comparing apparent, and absolute magnitude numbers we can estimate the stars distance from earth lxi. When m=M, then the star is located exactly 10 pc away lxii. When mM, then the star appears dimmer than it would 10 pc away 23. List the different types of electromagnetic radiation and their relative wavelengths, and energies. 24. List the pattern of motion of the large objects in the solar system. . All large bodies orbit in the same direction and nearly the same plane . Most rotate in the same direction

Wednesday, January 22, 2020

Technology Changes Role Of Database Administrator :: essays research papers fc

Technology Changes Role of Database Administrator The database administrator (DBA) is responsible for managing and coordinating all database activities. The DBA's job description includes database design, user coordination, backup, recovery, overall performance, and database security. The database administrator plays a crucial role in managing data for the employer. In the past the DBA job has required sharp technical skills along with management ability. (Shelly, Cashman, Waggoner 1992). However, the arrival on the scene of the relational database along with the rapidly changing technology has modified the database administrator's role. This has required organizations to vary the way of handling database management. (Mullins 1995) Traditional database design and data access were complicated. The database administrator's job was to oversee any and all database-oriented tasks. This included database design and implementation, installation, upgrade, SQL analysis and advice for application developers.. The DBA was also responsible for back-up and recovery, which required many complex utility programs that run in a specified order. This was a time-consuming energy draining task. (Fosdick 1995) Databases are currently in the process of integration. Standardizing data, once done predominately by large corporations, is now filtering down to medium- size and small companies. The meshing of the old and new database causes administrators to maintain two or three database products on a single network. (Wong 1995) Relational database management systems incorporate complex features and components to help with logic procedures. This requires organizations to expand the traditional approach to database management and administration. The modern database management systems not only share data, they implement the sharing of common data elements and code elements. (Mullins 1995) Currently, the more sought after relational database products are incorporating more and more complex features and components to simplify procedural logic. Due to the complexity of todays relational database, corporations are changing the established way of dealing with database management personnel. Traditionally, as new features were added to the database, more and more responsibility fell on the DBA. With the emergence of the relational database management system (RDBMS), we are now beginning to see a change in the database administrator's role.(Mullins 1995) The design of data access routines in relational database demands extra participation from programmers. The database administrator simply checks the system's optimization choice, because technology is responsible for building access paths to the data. Program design and standard query language (SQL) tools have become essential requirements for the database administrator to do this job. However, this technology requires additional supervision and many DBAs are not competent in SQL analysis and performance monitoring. The database administrator had to learn to master the skills of application logic and programming techniques. (Mullins 1995) The database administrator's job description and responsibilities have changed

Tuesday, January 14, 2020

Physical Activity and Obesity Essay

Childhood and adolescent obesity are prevalent in the United States (Nowicka 23; Clemmens and Hayman 801). This prevalence has caused widespread alarm and concern, particularly with respect to adolescent girls. The article of Clemmens and Hayman systematically reviews research on the interventions aimed at increasing physical activity among adolescent girls, with the aim in mind of avoiding obesity. The article rests on the premise that adolescence is an opportune time for interventions since it is the period where future health behaviors of people start (Clemmens and Hayman 801).   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   In order to make a comprehensive review of studies on interventions involving physical activities, the authors chose published journal articles from between 1989 and 2003, which featured experiments and trials involving adolescent girls and boys. Since physical activity is generally accepted as an effective means of addressing childhood obesity, many studies were conducted to determine how it could be effectively promoted among adolescents. Clemmens and Hayman found that interventions based in schools were effective in decreasing sedentary behavior among adolescent girls (Clemmens and Hayman 806).   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   Nowicka suggests that genetic factors aside, environmental factors such as physical activity and nutrition could be effectively addressed by a multidisciplinary team composed of an exercise expert, a dietitian, behavioral therapist, nurse, and physician. This ensures that different experts would be working harmoniously and simultaneously to solve a complex problem (Nowicka 28).   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   Some studies aimed to establish the relationship and association between weight gain and physical activity. One such study was conducted by Fogelholm and Kukkonen-Harjula. Unfortunately, this study resulted in inconsistent results, and it was concluded that that the effect of physical activity in weight reduction or gain is modest. It is further concluded that it is important to study means of promoting adherence to exercise programs in order to effectively manage weight (Fogelholm and Kukkonen-Harjula 109).   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   There is another study that sought to make clear the association between obesity and its history in the family and poor physical activity. This study, which was performed on high school students in public schools, led the authors to conclude that family history of obesity is associated with little physical exercise or activity or sedentary lifestyles and reluctance to exercise (Baba, Iwao, , Koketsu, Nagashima and Inasaka 272).   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   Jackson, Mannix, Faga and McDonald, on the other hand, discuss a study where mothers sought to have a plan in helping their children maintain healthy weight. This study, which discusses the role of increased physical activity in helping children achieve healthy weight, emphasizes weight management within the context of family life (Jackson, Mannix, Faga and McDonald 12).   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   Works Cited Baba, Reizo, Iwao, Nobuko, Koketsu, Masaaki, Nagashima, Masami and Hiroshi   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   Inasaka. â€Å"Risk of obesity enhanced by poor physical activity in high school students.† Pediatrics International 48 (2006): 268–273. Clemmens, Donna   and Laura L. Hayman. â€Å"Increasing Activity to Reduce Obesity in   Ã‚  Ã‚   Adolescent Girls: A Research Review.† JOGNN 33.6 (2004): 801-808. Fogelholm, M. and K. Kukkonen-Harjula. â€Å"Does physical activity prevent weight gain – a systematic review.† The International Association for the Study of Obesity 1   Ã‚  Ã‚   (2000): 95-111. Jackson, Debra, Mannix, Judy, Faga, Pat and Glenda McDonald. â€Å"Overweight and   Ã‚  Ã‚  Ã‚  Ã‚   obese children: mother’s strategies.† Journal of Advanced Nursing 52.1 (2005): 6-13. Nowicka, Paulina. (2005). â€Å"Dietitians and exercise professionals in a childhood obesity   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   treatment Team.† Acta Pà ¦diatrica 94(Suppl 448): 23–29      

Monday, January 6, 2020

case study Iridium - 1062 Words

Iridium Case Study Iridium is a famous case in which Motorola and other well known companies invested about $5 billion in a satellite venture that would enable a person to use his cell phone around the world. The investment included more than $2.2 billion in debt. Soon after operations began, the company declared bankruptcy and its assets were ultimately sold for only $25 million, leaving the lenders with a total loss. It is obvious that projections made by the company and endorsed by the most prestigious banks on Wall Street were comical leading to massive losses for banks, debt investors and equity investors. It is also clear that the company made some mistakes in marketing such as not having sufficient phones available after a†¦show more content†¦The phones were obviously bulky and there were service problems because the phones were difficult to use in buildings. Despite all of this, if the price was low enough, the system may theoretically be viable. Since most of the costs were fix ed, if the price was low enough to encourage much higher usage, maybe the technology would have been viable. I would like you evaluate the cost structure of the model through doing the following: Run a case with much lower prices – down to $.25 per minute on a retail basis (do this by adjusting the sensitivity factor for retail rates). Then increase the usage and compute the amount of usage required to break-even. What is the problem with this scenario in terms of the capacity of the satellite system. Step 5: General Discussion about Mistakes Made by Bankers In the final part of the case I would like you to think about the underlying mistakes made by lenders in making more than $2 billion of loans. Please do not simply say that projections of the number of subscribers and the price realized by the company were absurd –we all know that now. Address the question of whether an untested marketing plan on a new product with high prices is bankable under any circumstances. Discuss issues like: In general, can you make loans to companies when there is no operatingShow MoreRelatedManaging Information Technology (7th Edition)239873 Words   |  960 Pages CONTENTS: CASE STUDIES CASE STUDY 1 Midsouth Chamber of Commerce (A): The Role of the Operating Manager in Information Systems CASE STUDY I-1 IMT Custom Machine Company, Inc.: Selection of an Information Technology Platform CASE STUDY I-2 VoIP2.biz, Inc.: Deciding on the Next Steps for a VoIP Supplier CASE STUDY I-3 The VoIP Adoption at Butler University CASE STUDY I-4 Supporting Mobile Health Clinics: The Children’s Health Fund of New York City CASE STUDY I-5 DataRead Moreproject management case studies 4th edi1056 Words   |  5 PagesManagement. 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