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Saturday, 19 May 2012

The choice of subjects after class X

  
May 19th, 2012
The choice of subjects after class X is a very crucial decision in a student’s life and is often met with a lot of anxiety and confusion both on the part of parents and students alike. This anxiety is not out of place since on this decision hinges the general direction that a student’s career is going to take.
It is a common practice to base this crucial decision on the marks that the student obtains in his class X examinations. So, a student who secures an 80% plus aggregate in his class X Board Exams, invariably heads towards the Science subjects and another student who secures a 60% in his Boards, assumes that Humanities or the Arts subjects is what he must be cut out for. Such generalizations often prove erroneous and students may end up disillusioned and unduly stressed.
While performance in the class X final examinations may be a fair indication of the student’s hold over academic subjects, it should not be taken as the sole indicator for the level of aptitude and interest in any given area. Take the case of Arpita, who obtained a 75 % in her class X Boards. It is reasonable to assume that her Board exam result has been a function of such factors as
·         the level of preparedness
·         memory
·         exam taking skills
·         and level of anxiety on the day of exam;
·         others
Motivation or interest per se is likely to have played a relatively insignificant role. However, the scenario will change 2 years hence when she will be looking at her Class XII Board Exam results! Along with the factors listed above, her involvement with her subjects of study and her overall interest in the same will truly reflect in her final performance. This is because studies in the higher classes (Class XI and XII) get tougher and success in the examinations at this stage can be attained only by a consistent approach and an inquisitiveness to learn that is best brought about an inherent interest in the subject matter. It therefore brings us to the central point of this write-up that the choice of stream (or subjects) in class XI should be arrived at only after taking an individual student’s interest and aptitude into account.

Some pointers to keep in mind while choosing the subject combinations:
·         Know the subject combinations offered in your school at the +2 level. Typically the streams available in the schools and the subjects offered therein are:
*   Science (Medical): Physics, Chemistry, Biology
Optional subjects: Math, Engineering Drawing, Economics, Computer Science, Informatics Practices, Biotechnology
*   Science (Non-Medical): Physics, Chemistry, Math
Optional Subjects: Biology, Engineering Drawing, Economics, Computer Science, Informatics Practices
*   Commerce: Business Studies, Accounts, Economics
Optional Subjects: Math, Informatics Practices
*   Arts: History, Geography, Political Science
Optional Subjects: Economics, Psychology

One language (English is usually a compulsory subject in most schools)
·         Know your interests and aptitude. Co-curricular activities and inputs from friends & family can be valuable in this regard. You can also take the help of psychometric testing by certified guidance counselors.
·         Have a Career Plan revolving around a minimum of 3-4 careers in place.
·         Think it through yourself; what is good for your friend may not be good for you.
·         Explore career options and discover new opportunities that may excite you (this process should indeed continue within the broad field throughout the two years of plus two studies).
·         Be realistic and honest with yourself-no one knows you better than you do! If you know for instance, that you do not have a ‘Math-Brain’, do not fool yourself into taking Science.
·         Pay heed to the advice from parents and other adults who know you closely. Their experience can often provide you valuable insights both about yourself and the world of work.
It is important that you think through before taking this decision. Do not take it in haste or feel pressured in any way whatsoever.
All the Best!

Sunday, 16 October 2011

Train the Trainer-1



 1TEACHING ENGINEERING



It is possible to learn how to teach well. That is the thesis of my blog. This to help new lecturers get started toward effective, efficient teaching so that they can avoid the “new lecturer horror show” in the first class they teach. And by exposing them to a variety of theories and methods, we want to open the door for their growth as educators.  Teaching is a complex human activity, so it’s impossible to develop a formula which guarantees that it will be excellent. But by becoming more efficient, lecturers can learn to do a good job and end up with more time to do other things such as research.

WHY TEACH TEACHING NOW?
The majority of engineering lecturers have never had a formal course in education, and some can even produce a variety of challenging rationalizations why such a course is unnecessary:
1 I didn’t need a teaching course.
2 I learned how to teach by watching my teachers.
3 Good teachers are born and not made.
4 Teaching is unimportant.
5 Teaching courses have not improved the teaching in high schools and grade schools.
6 Engineers need more technical courses.
7 If I am a good researcher, I will automatically be a good teacher.
8 Even if a teaching course might be a good idea, none is available.

1 The first criticism can be answered in several ways. Just because someone did not need a teaching course does not logically imply that he or she would not have benefited from one. What is more important, times have changed. In the past, young lecturers received a good deal of on-the-job training in how to teach. New lecturers were mentored in teaching and were expected to teach several classes a semester. Now, mentoring is in research, and an lecturers in engineering at a research university may teach only one course a semester. In the past the major topic of discussion with older professors was teaching; now it is research and grantsmanship. Because of these changes, formal training in teaching methods is now much more important. The problems facing engineering education have also changed. In order to have enough engineers to remain internationally competitive, we must recruit, teach, and retain nontraditional students such as women and underrepresented minorities. There is also a moral imperative for reaching out to these nontraditional students.  Many students see the workloads of assistant professors as oppressive and do not want the sword of the tenure decision hanging over their heads. A course on efficient, effective teaching would reduce the trauma of starting an academic career and help these students to see the joys of teaching.

2 You undoubtedly learned something about teaching from your teachers, but what if they were bad teachers? Even if you did have good teachers, this method at best gives the new professor a limited repertoire and does not provide for any of the necessary practice. This approach also does not help you incorporate new educational technology into the classroom unless you have had the rare opportunity to take a course from one of the pioneers in these areas.

3 Some of the characteristics of good teachers may well be inborn and not made, but the same can be said for engineers. We expect engineers to undergo rigorous training to become proficient. It is logical to require similar rigorous training in the teaching methods of engineering professors. Experience in teaching engineering students how to teach shows that everyone can improve her or his teaching. Even those born with an innate affinity for teaching or research can improve by study and practice. Finally, in its extreme, this argument removes all responsibility and all possibility for change from an individual.

4 There is no doubt that teaching is very important to students, parents, alumni, accreditation boards, and state legislatures. Unfortunately, at many universities research is more important than teaching in the promotion process. When assistant professors are denied tenure, it is because of lack of research, not because they have not been good teachers. An efficient teacher can do a good job teaching in the same amount of time an inefficient teacher spends doing a poor job. New professors who study educational methods will likely be better
prepared to teach and will be more efficient during their first years in academia.

5 There is a general trend toward reducing the number of courses in pedagogy and increasing the number of content courses for both grade school and high school teachers. However, there is no trend toward zero courses or no practice in how to teach. The optimum number of courses in teaching methods undoubtedly lies between the large number required of elementary school teachers and the zero number taken by most engineering professors.

6 The demand for more and more technical courses is frequently heard at both the undergraduate and graduate levels. At the graduate level some of the most prestigious universities require the fewest number of courses. Thus, arguments that instructors must cover more technical content lack conviction at the graduate level. Courses on teaching can be very challenging and can open up entirely new vistas to the student. A course on teaching methods will be useful to all students even if they go into industry or government since logical organization and presentation of material are important in all areas.

7 Unfortunately, most research shows that there is almost no correlation between effective teaching and effective research. Frequently heard comments to the contrary often appear to be based on examples of good researchers who are also good teachers, while ignoring examples of good teachers who do not do research and examples of good researchers who are poor teachers. This should not be interpreted as a statement that
engineering professors should not do research. Ideally, they should strive to do both teaching and research well, and they should be trained for both functions.

8 There are a few courses in teaching in engineering colleges There are additional good reasons for learning how to teach. Teaching when you don’t know how may be considered unethical.  Engineers shall perform services only in the areas of their competence. Since teaching is a service, teaching when one is not competent is probably unethical.



THE COMPONENTS OF GOOD TEACHING
Exactly what characterizes a good teacher? Many adjectives come to mind when this question is asked: stimulating, clear, well-organized, warm, approachable, prepared, helpful, enthusiastic, fair, and so forth. Lowman (1985) synthesized the research on classroom dynamics, student learning, and teaching to develop a “two-dimensional model” of good teaching. The most important dimension is intellectual excitement which represents the teacher’s “obligation to knowledge and society” (Elbow, 1986). This dimension includes content and performance. Since most engineering professors think content is the most important, making this dimension the most important agrees with common wisdom in the profession. Included in intellectual excitement are organization and clarity of presentation of up-to-date material. Since a dull performance can decrease the excitement of the most interesting material, this dimension includes performance characteristics. Is the professor energetic and enthusiastic? Does the professor clearly show a love for the material? Does the
professor use clear language and clear pronunciation? Does the professor engage the students so that they are immersed in the material?

The second dimension identified by Lowman is interpersonal rapport which is the teacher’s “obligation to students” (Elbow, 1986). Professors develop rapport with students by showing an interest in them as individuals. In addition to knowing every student’s name, does the professor know something about each one? Does he or she encourage them and allow for independent thought even though they may disagree with the professor? Is the professor available for questions both in and out of class? Although engineering professors do not uniformly agree that interpersonal rapport is important, students consistently include this dimension in their ratings of teachers.

How do these two dimensions interact? Lowman (1985) divides intellectual development into high (extremely clear and exciting), medium (clear and interesting), and low (vague and dull). He divides the interpersonal rapport dimension into high (warm, open, predictable, and highly student-oriented), medium (relatively warm, approachable, democratic, and predictable), and low (cold, distant, highly controlling, unpredictable). To interpersonal rapport we have added a fourth level below low—punishing (attacking, sarcastic, disdainful, controlling, and unpredictable)—since we have observed professors in this category.

For example, a professor who is high in interpersonal rapport and low in intellectual excitement  will be considered a poorer teacher than a professor who is high in intellectual excitement and low in interpersonal rapport. Because their strengths are very different, these two teachers will excel in very different types of classes. The difference between these teachers and those at the high level of intellectual excitement is that the latter either consciously or unconsciously pay more attention to the performance aspects of teaching.  Although becoming a complete master is a laudable goal to aim for, teachers who have attained this level are rare. Hanna and McGill (1985) contend that the affective aspects of teaching are more important than method. Affective components which appear to be critical for effective teaching include:

Valuing learning
• A student-centered orientation
• A belief that students can learn
• A need to help students learn

High intellectual excitement is impossible without valuing the learning of content and a need to present the
material in a form which aids learning. High interpersonal rapport requires a student-centered orientation and a belief that students can learn. A few comments about the punishing level of interpersonal rapport are in order. Since most students will fear such a professor, they will do the course assignments and learn the material
if they remain in the course and aren’t immobilized by fear. However, even those who do well will dislike the material.  The only justification for a punishing style is to train students for a punishing environment such as that
confronted by boxers, POWs, sports referees, and lawyers. Professors who stop attacking students immediately move into the level of low interpersonal rapport and receive higher student ratings.





PHILOSOPHICAL APPROACH
Teaching is an important activity of engineering professors, both in regard to content and in relation to students. New professors are usually superbly trained in content, but often have very little idea of how students learn.

Unfortunately, for too many teachers lecturing is often synonymous with teaching. In an attempt to broaden the reader’s repertoire of teaching techniques, we include other teaching methods which may be more appropriate for some courses. Because advising and tutoring are closely tied to teaching, we also include these one-to-one activities. And since we believe that learning to become a good problem solver and learning how to learn are two
major goals of engineering education, we also cover methods for teaching students to attain these goals.

Engineering professors invariably serve as models of proper behavior. Thus, an engineering professor should be a good engineer both technically and ethically, not using his or her position to persecute or take advantage of students. A welldeveloped sense of fairness is almost uniformly appreciated by students. Our position on human potential is that people want to learn. Therefore, we search for ways to stop demotivating students while realizing that a few discipline problems always exist. Teaching is an important activity of engineering professors. Since they must also be involved in varying amounts of research, administration, advising, committee work, consulting, and so forth, we emphasize both effectiveness and efficiency.




WHAT WORKS: A COMPENDIUM OF LEARNING PRINCIPLES

 

1 Guide the learner. Be sure that students know the objectives. Tell them what will be next. Provide organization and structure appropriate for their developmental level.
2 Develop a structured hierarchy of content. Some organization in the material should be clear, but there should be opportunities for the student to do some structuring. Content needs to include concepts, applications and problem solving.

3 Use images and visual learning. Most people prefer visual learning and have better retention when this mode is used. Encourage students to generate their own visual learning aids.

4 Ensure that the student is active. Students must actively grapple with the material. This can be done internally or externally by writing or speaking.

5 Require practice. Learning complex concepts, tasks, or problem solving requires a chance to practice in a nonthreatening environment. Some repetition is required to become both quick and accurate at tasks.

6 Provide feedback. Feedback should be prompt and, if at all possible, positive. Reward works much better than punishment. Students need a second chance to practice after feedback in order to benefit fully from it.

7 Have positive expectations of students. Positive expectations by the lecturers and respect from the lecturers are highly motivating. Low expectations and disrespect are demotivating. This is a very important principle, but it cannot be learned as a “method.” A master teacher truly believes that her or his students are capable of great things.

8 Provide means for students to be challenged yet successful. Be sure students have the proper background. Provide sufficient time and tasks that everyone can do successfully but be sure that there is a challenge for everyone. Success is very motivating.

9 Individualize the teaching style. Use a variety of teaching styles and learning exercises so that each student can use his or her favorite style and so that each student becomes more proficient at all styles.

10 Make the class more cooperative. Use cooperative group exercises. Stop grading on a curve and either use mastery learning or grade against an absolute standard.

11 Ask thought-provoking questions. Thought-provoking questions do not have to have answers. Posing questions without answers can be particularly motivating for more mature students.

12 Be enthusiastic and demonstrate the joy of learning. Enthusiasm is motivating and will help students enjoy the class.

13 Encourage students to teach other students. Students who tutor others learn more themselves and the students they tutor learn more . In addition, students who tutor develop a sense of accomplishment and confidence in their ability.

14 Care about what you are doing. The professor who puts teaching “on automatic” cannot do an outstanding job.

15 If possible, separate teaching from evaluation. If a different person does the evaluation, the teacher can become a coach and ally whose goal is to help the student learn.





 



 


 

Saturday, 10 September 2011

Aircraft Fuel

Aviation fuel
Aviation fuel is a specialized type of petroleum-based fuel used to power aircraft. It is generally of a higher quality than fuels used in less critical applications, such as heating or road transport, and often contains additives to reduce the risk of icing or explosion due to high temperatures, among other properties.
Most aviation fuels available for aircraft are kinds of petroleum spirit used in engines with spark plugs, i.e. piston and Wankel rotary engines, or fuel for jet turbine engines, which is also, used in diesel aircraft engines. Alcohol, alcohol mixtures and other alternative fuels may be used experimentally, but alcohol is not permitted in any certified aviation fuel specification.
Avgas is sold in much lower volumes, but too many more individual aircraft, whereas jet fuel is sold in high volumes to large aircraft operated typically by airlines, military and large corporate aircraft.
The Convention on International Civil Aviation, which came into effect in 1947, exempted air fuels from tax. Australia and the USA oppose a worldwide levy on aviation fuel, but a number of other countries have expressed interest.
Avgas
Avgas (aviation gasoline) is an aviation fuel used to power spark-ignited piston-engine aircraft. It can be distinguished from mogas (motor gasoline), which is the everyday petroleum spirit used in cars. Avgas is formulated for stability, safety, and predictable performance under a wide range of environments, and is typically used in aircraft that use reciprocating or Wankel engines. Dyes for the fuel are required in some countries:
Table of Aviation Fuel Types
Country
Fuel
Lead content
Status
Dye
Worldwide
Low lead
Phased out, difficult to obtain
red
Worldwide
Unleaded
Not produced since 2008
purple
Worldwide
Low lead
Most commonly used aviation fuel
blue
Worldwide
4 grams of lead per US gallon (1.1 g/l)
In process of being replaced by 100LL
green
Worldwide
Discontinued (sometimes produced for races)
brown
Worldwide
Discontinued (mainly military use)
purple



Jet fuel
Jet fuel is a clear to straw-colored fuel, based on either an unleaded kerosene (Jet A-1), or a naphtha-kerosene blend (Jet B). It is similar to diesel fuel, and can be used in either compression ignition engines or turbine engines.

Aviation fuel is often dispensed from a tanker or bowser, which is driven up to parked aircraft and helicopters. Some airports have pumps similar to filling stations up to which aircraft must taxi. Some airports also have permanent piping to parking areas for large aircraft.
Regardless of the method, aviation fuel is transferred to an aircraft via one of two methods: overwing or underwing. Overwing fuelling is used on smaller planes, helicopters, and all piston-engine aircraft. Overwing fuelling is similar to car fuelling — one or more fuel ports are opened and fuel is pumped in with a conventional pump. Underwing fuelling, also called single-point, is used on larger aircraft and for jet fuel exclusively. For single-point fuelling, a high-pressure hose is attached and fuel is pumped in at 40 PSI and a maximum of 45 PSI. Anything higher needs to be stopped, for it can cause damage to the wings. Since there is only one attachment point, fuel distribution between tanks is either automated or it is controlled from a control panel at the fuelling point or in the cockpit. A dead man's switch is also used to control fuel flow.
Because of the danger of confusing the fuel types, a number of precautions are taken to distinguish between avgas and jet fuel beyond clearly marking all containers, vehicles, and piping. Avgas is treated with either a red, green, or blue dye, and is dispensed from nozzles with a diameter of 40 millimetres (49 millimetres in the USA). The aperture on fuel tanks of piston-engined aircraft cannot be greater than 60 millimetres in diameter. Jet fuel is clear to straw-colored, and is dispensed from a special nozzle called a "J spout" that has a rectangular opening larger than 60 millimetres in diameter, so as not to fit into avgas ports. However, some jet and turbine aircraft, such as some models of the Astar helicopter, have a fuelling port too small for the J spout, and thus require a smaller nozzle to be installed to be refuelled efficiently.
Energy content
The net energy content for aviation fuels depends on their composition. Some typical values are:[1]
  • BP Avgas 80, 44.65 MJ/kg, density at 15 C is 690 kg/m3
  • Kerosene type BP Jet A-1, 43.15 MJ/kg, density at 15 C is 804 kg/m3
  • Kerosene type BP Jet TS-1, (for lower temperatures) 43.2 MJ/kg, density at 15 C is 787 kg/m3
Chemical composition
Aviation fuels consist of blends of over a thousand chemicals, primarily hydrocarbons (paraffins, olefins, naphthenes, and aromatics), as well as additives, such as antioxidants and metal deactivators, and impurities. Principal components include n-heptane and isooctane. Like other fuels, blends of aviation fuel used in spark-ignited piston-engined aircraft are often described by their octane rating.
Safety precautions

Any fuelling operation can be very dangerous, and aviation fuel has a number of unique characteristics which must be accommodated. As an aircraft flies through the air, it can accumulate a charge of static electricity. If this is not dissipated before fuelling, an electric arc can occur, which may ignite fuel vapors. To prevent this, aircraft are electrically bonded to the fuelling apparatus before fuelling begins, and are not disconnected until fuelling is complete. Some regions require the aircraft and/or fuel truck to be grounded, as well.[2]
Aviation fuel can cause severe environmental damage, and all fuelling vehicles must carry equipment to control fuel spills. In addition, fire extinguishers must be present at any fuelling operation, and airport firefighting forces are specially trained and equipped to handle aviation fuel fires and spills. Aviation fuel must be checked daily and before every flight for contaminants, such as water or dirt.
Many airlines now require safety belts be left unfastened should passengers be aboard when refuelling happens.

A Carson Helicopters S-61N Fire King being refueled during firefighting operations in Southern River, Western Australia.