GGRB02H3 Lecture : Logic of Geographical Thought

325 views3 pages

blueserval947

2 Feb 2012

School

UTSC

Department

Geography

Course

GGRB02H3

Professor

Rajyashree Narayanareddy

For unlimited access to Class Notes, a Class+ subscription is required.

Document Summary

Mid-term exam short answer, definitions, no multiple choice. Oil is our anchor for the discussion of what can be abstract scholarship on geographic thought. Oil is an object, a thing but also a process. Humans have transformed oil: spaces, places, and environments are also changed and transformed. Oil in turn has transformed us: we have become oil (what does that mean: society is also affected by oil war, conflict, scale of the body. Space is a plane on which events takes place. Geographers are interested in understanding geographical area thus they draw boundaries on areas and understand it along multiple lines of difference region, locality, and place. Common aspect they share is space is not given: relational view of space. Space is not container; space is constructed: remake of space as well, the interaction with space. Four spaces (nigel thrift): empirical space, unblocking space. Space is constructed; something as basic as road signs and measurement.

Related Questions

During your biking tour of the Pacific Northwest, you decidetooutdo those latte-guzzling ecotopians at their own game. Insteadofthe four toxic and disposable 1.5-volt batteries suggested foryourwalkabout CD player, you will place a 2.0 m conductingwandacross your handlebars. Pedaling furiously in adirectionperpendicular to the local magnetic field, you wish to gofastenough to induce a potential difference of 6.0 V (equivalenttofour batteries in series). (a) The strength of the Earth'smagneticfield at your location is 5.0Ã10â5 T. Howfast will you need to go?(b) Is this speed street-legal? (c) Themagnetic declination at yourlocation is 19Â°. At what anglefrom geographic north should youtravel to maximize the potentialdifference of yourenvironment-friendly arrangement?

Vapor cycles
5EM - Thermodynamics
September 2010
1 The T-S diagram
The temperature-entropy diagram is an alternative to the well knownpressure-
volume diagram. Before using it to analyze different vapor cycles,we need
to understand it properly.
1. Plot the following transformations for ideal gases in a T-Sdiagram
(a) Isothermal expansion
(b) Isobaric expansion
(c) Isometric heating
(d) Reversible adiabatic expansion
(e) Irreversible adiabatic expansion
2. Repeat the last question, but this time do it for a realsubstance,
starting in the compressed liquid1 region and ending in thesuperheated
region, when possible. Indicate the boundaries of eachregion.
3. We know that under certain circumstances the area under theplot
in a P-V diagram represents the work performed during theprocess.
What does it represent in this case? Under what assumptions isyour
answer true? Compare examples 6.1 and 6.2.
2 Thermal machines
We understand by thermal machine a device capable of transformingther-
mal energy (heat) into mechanical energy (work). We already knowthat
these machines have a limited efficiency which, in the two-sourcesmodel, is
obtained by Carnotâs cycle.
(Compressed liquid is sometimes also called subcooled liquid)
2.1 Carnot cycle
This cycle, although efficient, is impractical. To begin with, theextreme
temperatures of the cycle should be within the sources temperaturesfor a
finite heat flow to exist.
1. Given the temperature of the sources, draw the cycle accordingto the
named limitation.
2. Show that this leads to lower efficiency than the theoreticallimit.
3. Assume that heat flow from/to the sources is proportional to thetem-
perature difference between them and the working fluid, anddemon-
strate that a higher power output is related to a decreasedefficiency.
2.2 Rankine cycle
Out of the several practical possibilities, Rankine cycle and itsvariations is
widely used, especially for electric power generation.
1. Draw the basic cycle in a T-S diagram and explain it.
2. What does the efficiency of the cycle depend on? Comparewith
Carnotâs.
3. What are the differences between the ideal cycle and the realone?
4. Describe how it is modified by superheating and/or reheating.Explain
te benefits.
2.3 Problems
After answering the previous questions solve the followingexercises from the
book: 8.2, 8.4, 8.5, 8.13, 8.19, 8.20
3 Frigorific machines
3.1 Reverse Carnot cycle
We have already studied Carnot cycle in detail as the ideal thermalmachine.
Now we will take is as the starting point to understand thecharacteristics
of frigorific machines.
1. Draw the ideal cycle in a T-S diagram and explain it.
2. Show that this cycle has a theoretical efficiency Ã =Tcold/Thot-Tcold
3. What are the difficulties in implementing such cycle in actualdevices?
3.2 Actual refrigerators
1. Why is the turbine replaced by an expansion valve in mostcases?
2. Plot the actual cycle and explain the differences with the idealcase.
3. How do cascade and multistage systems improve the performanceof
the refrigerator?
4. What aspects are important in the choice of a refrigerant fluid?Justify
3.3 Problems
After answering the previous questions solve the followingexercises from the
book: 10.2 10.7, 10.8, 10.9, 10.22, 10.23 10.1D

GGRB02H3 Lecture : Logic of Geographical Thought

Document Summary

Get access

Related Documents

GGRB02H3 Lecture : first lecture

GGRB02H3 Study Guide - Midterm Guide: Peter Haggett, Rand Mcnally, Mary Kingsley

GEOG 1410 Quiz: Human Geography

Related Questions