Thursday, December 27, 2012

DnD Characters

These are links to character sheets for the campaign
  1. Dan the Dragon Adept
  2. Andy
  3. Nick
  4. Natasha

Sunday, December 23, 2012

DnD Forgotten Realms description

The following is a map and description of regions in the Forgotten Realms.

Political Maps

Trade Map

  • Anauroch
    • A desert wasteland currently occupied by two main peoples
      • Bedine
        • group of nomadic barbarians
      • Shadovar
        • The last remaining Netherese
        • Citizens of the floating city of Shade

    • History
      • This is the location of the ancient civilization Netheril. During this time the power of human mages was at its highest, and the display of their might was characterized by their floating cities. The 

DND Campaign

Towers Campaign a campaign hosted on roll 20 listed here: campaign

The following is a collection of materials related to a forgotten realms dnd campaign, to be run sometime in the future
  1. Premise
  2. Maps/Setting
  3. Character Sheets

DND Campaign Intro

Campaign Backstory

Once again a time of troubles has hit the land of Faerun, though perhaps not The Time of Troubles where the gods fell from their place in the heavens. In Evereska, the last home of the elves on the mainland, the elf Galaeron and his tomb wardens encountered a group of human crypt breakers in the tombs of their Vyshanti elders. The humans were from Vaasa, nobles of the granite tower, wielders of the darkblades and servant to Telamont Tanthul, a netherese arcanist from the city of shade. Although these humans were breaking into the ancient elven crypts, they were not after the jewels and riches hidden in the tombs. They brought along a beholder, and were using its disintegration rays to dig deeper into the walls of one of the ancient tombs, to reveal the Sharn Wall.

The Sharn Wall is an ancient work of magic erected by the Netherese, along with the help of the Sharn, a relatively unknown race of sorcerers. The Netherese are citizens of Netheril, the greatest and most powerful civilization of human wizards. They were famous for using their magic to create floating cities by severing the top of mountains and inverting them to build their floating cities. Near the end of Netheril's reign, they fought against an enemy called the Phaerimm, a race of floating wormlike creatures armed with powerful magic, the ability to eat magic, and the ability to spawn their young by implanting their eggs within their victims. They came from the outer planes, and are one of the most deadly invaders Faerun had to face in its entire history.

The most powerful mage of the time Karsus wanted to end the war between the Phaerimm and Netherese as neither side could gain a definitive advantage over the other, and as time went on, the Phaerimm were draining the life out of the earth where Netheril stood. Karsus in his hubris could not bear this blemish on the land that he owned, and decided to gain control over all magic in the world to use to eradicate all Phaerimm simultaneously. Due to his power he actually succeeded and wrested control of the weave of magic from Mystryl the goddess of magic at the time. However, he could not handle the influx of information and did not have the control necessary to direct his new powers, resulting in the fall of the Netherese cities. The Phaerimm now held an advantage but with the help of the Sharn and the new goddess of magic Mystra, the remaining Netherese were able to lock the phaerimm behind the Sharn Wall, in the Plane of Shadow. However, this was where the last functioning city of Netheril fled to. Shade, the city of shadow arcanists, fled to the plane of shadow right before Karsus caused the fall of Netheril. However, they were also locked behind the Sharn Wall with the Phaerimm in the plane of shadow, destined to fight for against its denizens for all eternity.

Through what is thought to be a misunderstanding, a magic missile from Galaeron and a bolt of shadow magic from Telamont, mixed together which caused a breach in the Sharn wall. This allowed a few phaerimm to escape, and the pride of the elves caused them to underestimate what was necessary to push them back. Soon more Phaerimm escaped, and Evereska is now in a full scale war. All active Chosen of Mystra have been called to help deal with this threat, with only a few exceptions. Elminster Aumar is now missing, due to an accident involving the princes of the city of Shade, Elminster was forced to fix a rift to hell caused by yet another blending of shadow and pure arcane magic. He was unable to seal the rift from Faerun, and is now lost in Avernus the first of the 9 hells. The Simbul Witch Queen of Algarond is likewise missing, as she searches for her consort Elminster. Sylune, the witch of Shadowdale, remains dead. Qilue, servant to Elistraee goddess of the the good aligned Dark elves, as well as Chosen of Mystra is busy protecting her temple in Undermountain, as the disappearance of Halaster Blackcloak, archmage and creator of Undermountain, caused a lack of stability in the region. All other chosen, from the Seven sisters, as well as Khelben Arunsun are now dealing with the threat of the Phaerimm in Evereska.

Campaign Introduction

Without the help of the most powerful mages, the harpers are lacking the resources necessary to keep track of events in Faerun. One such harper is the archmage of the seelie courts, Torden Kane. Kane noticed that there appears to be some coordinated events that could have disastrous results to the future of Faerun. To deal with this, he has created a chamber in his castle that utilizes an inverted version of planar binding to summon powerful beings of the material plane in Faerun to his own demiplane, which he then binds to his service using a powerful geas. This allows him to investigate these events without using his time as he is also aiding in the defense of Evereska.

This chamber currently has 5 summoning circles that are active at any given time. The current summoning has hooked a bard/priest, a dragonfire adept, a disciple of dispater, and a knight with his squire. An image of Kane appears in front of them, and commands them using a geas.
"Heroes and villains head my command, I order you to investigate the city of Darmshall in Vassa. On an outlying farm, a well now appears to be a spring of healing. One day there was barely enough water to distribute among the folk, the next clear water gushed from the spring, and those who drank from it were healed of aches and pains. Upon hearing of this, the necromancer Persephone, has launched an undead assault on the citizens of this village. Assess and deal with the situation as best you can and you'll be free from my geas."

"The enemies we face acts together in concert. Regardless of your differences, you must work together to overcome them and preserve the future of Faerun as the threat behind this events and others like it threaten everyone, from the Knights of Tyr to the servants of Asmodeus. To increase your coordination, my attendant will lead you to a room where you will test yourselves against my apprentices. Should you succeed in defeating them you will be transported to the outskirts of Darmshall to begin your mission."

You are standing in a large room made entirely out of ice. The circles that summoned and bound you lie at your feet. Immediately to your left is an icy wall marked with 5 glyphs which all appear to have activated, followed by a series of doors to some small rooms. To your right are windows that show a curious environment. You appear to be in a valley about 2 miles wide that is half covered in ice and darkness, that is separated from the other half by a river. Across the river lies an extremely bright area covered in trees. In front of you about 50 feet down is a large door, behind you is a stone wall. A hound sits idly by appearing to wait for your instructions.

Saturday, December 8, 2012

Textbook Notes ToC

The following are links to my notes on a variety of textbooks.

Sustainability Ethics Tanenbaum
The above are notes on an ethical approach to sustainability. The above are notes I've written on Tanenbaum's Computer Networks.
Wind Turbine Technology Farlow
The above are notes on Farlow's PDE for Scientist and Engineers The above are notes on an introduction to Wind Turbines
Intro to Smart Grid Cloud Applications and Architecture
The above are notes for a class on an introduction to the Smart Grid The above are notes for a book on cloud applications and architecture
Introduction to Cryptography with Coding Theory
The above are notes for Cryptography

Trivia - A Google a Day LXV

Where does the general of the Venetian army smother his wife in Shakespeare's tragedy "Othello"?
In Their Bed

What treaty ended the war that had been incited by the assassination of Archduke Franz Ferdinand?
Treaty of Versailles

What bird, whose name has come to be synonymous with "stupid", was made extinct in less than 100 years by virtue of the destruction of its habitat?

What implement does Ms. Williams use to stab herself and frame her friend with in Arthur Miller's allegorical play about hysteria in America?
A Needle

What is the only bird that is able to swim but unable to fly?

In what county is the lowest point in the United States?

What was the relationship of the winner of the 2009 Oscar for Best Director to the nominee for "Avatar" in the same category?

Which former NBA player legally changed his first name on the first anniversary of John Lennon's death?
World B. Free

Which former MLB big hitter was born on the exact same day as the professional wrestler known as "Disco Inferno"?
Sammy Sosa

Which former Commissioner of Baseball had a son who has been nominated for an Academy Award?
A. Bartlett Giamatti

Friday, December 7, 2012

Trivia - A Google a Day LXIV

What is it called when a solid becomes a gas without first passing through the liquid phase of matter?

The name of the capital of what country likely comes from the name of the son of Ptolemy, who rebuilt the city in the 3rd century B.C.?

Which of the Beatles' album covers was designed and created by the band's longtime friend, Klaus Voormann?

Greg Maddux won four consecutive Cy Young Awards in the 1990's playing for the Atlanta Braves and which other team?
Chicago Cubs

Whom did George Lucas pick for the role of Indiana Jones, though a TV contract forced the actor to bow out?
Tom Selleck

What popular science author wrote a bestselling book in 1980 with thirteen illustrated chapters that later became thirteen episodes of a popular TV show about the cosmic world?
Carl Sagan

Who is the president of the entire star system according to Douglas Adams' 1979 novel?
Zaphod Beeblebrox

What appears over the body of each dead sailor and animates the bodies on the mariner's ship described in Coleridge's addition to "Lyrical Ballads"?

Which former NHL player and now head coach shares his name with an Eisner Award-winning graphic novelist?
Joe Sacco

When J.K. Rowling vetoed Chris Columbus' non-British pick for the lead in "Harry Potter and the Sorcerer's Stone", what movie did the young actor then star in?
Lemony Snicket's A Series Of Unfortunate Events

Practice Schedule 1

Practice Schedule

Sunday Monday Tuesday Wednesday Thursday Friday Saturday
# of Arrows Shot N/A N/A N/A N/A 0 90 126
Indoor round score N/A N/A N/A N/A 0 N/A
Miles Ran N/A N/A N/A N/A 0 1/4 1/2
Push Ups N/A N/A N/A N/A 0 20 20
Crunches N/A N/A N/A N/A 0 40 40
SC Ladder Games N/A N/A N/A N/A 2 3 1
LoL Matches N/A N/A N/A N/A 0 0

Thursday, December 6, 2012

Paper - Sustainability Agenda

Sustainability Agenda

        What is the most important thing engineers can do to help realize a sustainable energy future? The most important role is for engineers to provide their services in different areas and professions. They should spread their influence through the sectors of politics and management in order to help companies and the rest of the nation realize what sustainability entails. Although spreading information allows for people to make informed rational decisions, what is more effective is when someone who already has that information is put in a position that can promote a sustainability agenda.

        First we must address the concept of rationality. Rational decisions involve complete knowledge of the situation and making a choice based on the most benefits and least disadvantages. One of the most common obstacles to this is simply that the general population on average isn’t informed about topics and issues, in this case sustainability. There are multiple ways to approach this. The first way is best handled by educators, which is to teach the subject. This is the most direct way to address the problem which is to directly tell people about it and help them learn about the subject. This is a huge role and vital to the sustainability cause however, it is not the primary role of the engineer. They’re not put in a position where they can influence change by teaching the next generation, but they can educate their coworkers and other members in the workplace.

        Currently there are restrictions built into the social structure of the workplace. In general, most engineers do not get to make high level decisions. Level refers to the level of design that the engineer is operating at. Low level design is where the majority of engineers work, which is on a small component of the overall project, for example managing tcp/ip or udp connections in computer networking. An upper level design for the same project would be something like working on the application skype and detailing how it groups multiple people into one phone call. This would be an upper level design specification or project. More computer engineers are required for the low level design and maintenance of the program, and fewer are needed for the upper level decisions. Those high level decisions are generally reserved for the more experienced employees in the field.

        However, since sustainability is a recent concern, the experienced employee’s in the workplace don’t have the same focus in their education on these kind of ethical and long term concerns. Thats why it’s important for newcomers to all fields of engineers to be more vocal about sustainability. In the workplace, there are often forums and associations where engineers can talk and share concerns about a project. Normally this involves meeting tight constraints on time to market, or on fulfilling design specifications. However, it’s important for sustainability to become worked into the main components in the design process rather than as an afterthought. New engineers must have the courage to try and promote sustainability to management and higher level engineers who can influence policy on those levels.

        The other way is simply to be in those positions with a modern engineering background. Engineers who have been trained to think in terms of sustainability have to take an active role to control those upper level decisions that are usually reserved for senior members and management. This is simply a matter of time as engineers progresses in their career, they are able to gain more influence over projects as well as climb up the corporate ladder. The reason this is a necessary step beyond simply trying to inform upper management is because of an issue pointed out in The Ethics of Sustainable Resources by Donald Scherer. The current management is already set in their ways. They are already in a high position and often wealthy, so they are buffered from economic shocks and will be among the last people to feel the effects of the sustainable energy crisis because they can buy their way out of issues. This means that the main way to make your voice heard, is to put yourself in a position of power. This allows for the company to head in a sustainable direction because you have the training and access to information to make good rational decisions about the subject of sustainability.

        Another area where engineers need to make their voice heard is in the political sphere. Most politicians aren’t qualified to speak on scientific and mathematical matters because their background did not include that training, since they mostly consist of political science or law majors. Engineers on the other hand have the training and judgement to analyze scientific and mathematical data which is necessary to properly discuss sustainability issues.

        Luegehnbiehl in his article on Ethical Principles for Engineers in a Global Environment lays out foundational principles of engineering ethics which give us reasons why it is necessary for engineers to put themselves on the political field. The principle of engineering competence say that engineers should strive to carry out work that they are capable of. In this case it is dangerous to let those with a pretense of knowledge rather than formal training make decisions about a subject they aren’t qualified to debate about. This means that we need some engineers to extend themselves beyond their own fields in order to exert their influence on different sectors in society to properly promote a sustainability agenda.

Paper - Ethical Motivation for Sustainability

Ethical Motivation for Sustainability

        The engineering profession holds a large amount of responsibility to promote sustainability because of both the knowledge and skills engineers have. Engineering transforms our raw materials into usable products, which means that it’s responsible for consuming the vast majority of our resources. Engineers are some of the few people aware of what goes on in the process of manufacturing, and their possible consequences. Therefore that knowledge binds them by duty to be responsible for both the direct and indirect consequences of their actions.

        Why should engineers care about sustainability? Here we have to establish the ideas of justice and distribution. If we care only about the present, there isn’t really any reason for engineers to concern themselves about sustainability since there are enough resources right now to be distributed among humanity to support enterprise and construction. However, this will not always be the case. Sustainability means that the rate at which we use resources is less than the rate that resource replenishes itself. Since we are using resources in an unsustainable way through the use of fossil fuels, we are facing a crisis where our civilization will eventually run out of usable resources. Estimates show that this will be sooner rather than later. This means that we have to worry about distribution of resources in a temporal way in order to preserve intergenerational justice.

        Intergenerational justice is the idea that we have an obligation to preserve the livelihood of future generations, which is an extension of the golden rule. The golden rule of ethics is the idea that we should treat others the same way that we would want to be treated ourselves, and it is found in every society on earth in one form or another. Intergenerational justice applies this not only to the people who live right now but the people who will live. If our generation uses up so many resources that it impinges on the ability for future generations to survive it would be unethical and a violation of the golden rule. A journal article Sustainability and Intergenerational Justice by Brian Barry goes over the specifics of intergenerational justice. Intergenerational justice assumes that we want progress for humanity as a whole. If we reverted to living like cavemen, sure we would solve the sustainability crisis, but it would not be just. Justice involves ensuring that quality of life of future generations is either equal or better than it is now. This is why we have to examine the engineering profession that create products and services since those items often increase quality of life.

        What role does the engineer serve in society? Alastair Gunn in his Integrity and the Ethical Responsibilities of Engineers notes that engineering is a unique profession with its own specialized concerns. Engineering projects are expected to be 100% successful, something that is not generally expected from a profession. For example, we expect that once a bridge is built it will stand and not fail. Engineers are unique in that they deal with the concerns of a large body of users, rather than singular interactions. An example of this is that a doctor visibly meets with their patients and interacts with them. On the other hand an engineer who works on a project is usually only in charge of a small aspect of it, and interacts with the user indirectly after the product has been assembled, purchased, and then used. This means that there are many layers of separation between the engineer and his end customer, which makes it difficult to see what responsibilities engineers have to society and their customers. However, the engineer must be able to live up to the expectation of 100% success with their projects, as it can often lead to disaster such as in the example case of a faulty bridge.

        So even though a single engineer can only control a particular aspect of a project, it is their role in society to make sure that projects are as successful as possible. Success in this case must adhere to the ideas of intergenerational justice in order to remain ethical because of the impact engineering has on future generations. Thus in order to live up to the role in society that is expected of them engineers must promote sustainable policies and practices.

Paper - Obstacles of Sustainability

Obstacles of Sustainability

The greatest obstacle to obtaining a sustainable energy future lies in the the organizational structure of our society in both a social and economic sense. It is currently difficult to promote new thought into our societal systems because large companies have become so established on a global scale. The central issues in design and development involve design constraints and time to market. Companies rarely take into account the long term environmental effects of their actions, which needs to become part of the normal operations of more companies. In addition, sustainability is an investment into the future, which contrasts with the in the present mindset of a market economy.

The first obstacle we need to address is the inflexibility of a market economy. In theory the free market allows for everyone to compete without governmental restrictions. This allows for products and services to freely compete letting the best service win out.  Although this seems like a system that gives everyone a fair chance at success, this isn’t always the case. The market economy is fair when a technology is in development, however it becomes inflexible once technologies have been established. Once a company becomes established, it becomes very difficult for newcomers to break into that market. 

The issues stems from capital. Older companies have more money and resources to do further research and development for their product. This means that their product will likely be better suited for its end result than a new company which limits change. Another benefit of having extra capital is that it gives the company the option to buy up smaller companies in order to reduce competition. Examples of companies that were able to achieve this kind of domination in a market are the companies Microsoft and Bell, both of which used to hold an almost complete monopoly in their respective markets. Although now this dominance has been somewhat broken, it took the intervention of the government to reduce the power of Bell Labs, and drastically different design goals to allow companies like Apple, or heavy utilization of open source products like Linux to compete with Microsoft.

This concept comes from the Theory of Innovation which states that a social system is made up of five different kinds of people: the innovators, the early adopters, the early majority, the late majority, and the laggards. In the field of sustainable energy sources for energy generation already exist with  the coal and petroleum industries, which puts us in a social system where people are mostly made of the late majority. The late majority are people who are comfortable and accustomed with existing products. Because they are already comfortable with the situation, they are resistant to change, and this includes not only the fossil fuel companies, but also their customers which includes the vast majority of the entire population. Most people already use electricity and gas in order to live in their homes and drive around for work or leisure. This means that sustainable energy, is in that difficult stage where the market is normally unfriendly towards it as well as having to deal with competition from large already established industries.

In order to make sustainable energy viable in the market, there has to be some kind of incentive socially and economically. The social motivation is thankfully already there, and simply needs time and effort to grow. Forms of media ranging from presentations by presidents, to books such as the post carbon reader series serve to inform the public that we are in an energy crisis and that there is a need for alternative sustainable energy sources. Heinberg’s article What is Sustainability in the post carbon reader gives us a set of axioms explaining why sustainability is necessary. His first axiom is that “Any society that continues to use critical resources unsustainably will collapse.” This points out the fact that unsustainable practices, even if you are for some reason skeptical of the effects of global warming, will still result in the loss of resources, and the potential for societal collapse because of our limited resources.

More scientific articles such as Smil’s Science, Energy, Ethics and Civilization show us the immediacy of these issues. We are already hitting the point where our consumption of resources is hitting Eath’s natural limit and can only last for about 1 or 2 more generations without change. So we know that social motivation for sustainability exists. However, why hasn’t this been effective in motivating action? The answer is twofold.

First we also need to worry about the economic aspect because in order for technologies to be implemented, someone must be able to make a profit from that technology. The issue is that since alternative energy restructures existing technology, and is still in development, the initial cost of most sustainable energy generation is much higher than conventional fossil fuel generation. A good example is electrical wind generation. Wind power has historically been so cost inefficient that generators have only been built during the years where the government gives out huge tax/rebate incentives. Whenever those incentives run out, construction immediately halts as it is no longer profitable. Although this is a more extreme case, sustainable energy has trouble becoming profitable.

Secondly, sustainability is a long term concern. In general people are concerned with their day to day activities, not what will occur 20+ years in the future, and even when we are, the scope of our concerns are usually limited to our immediate family, such as our children. Sustainability concerns the survival of humans as a race, rather than concerning the individual or their families. This means that the sheer scope of sustainability hinders most people from taking action because they are all too willing to place responsibility for that on someone else, and keep their concerns focused on their day to day lives. This is why even though there are some efforts already in place to address the social and economic problems inherent to sustainability  they still remain as the biggest challenge for the sustainability movement to overcome.

Sunday, December 2, 2012

Notes - Glossary

The following notes are taken from Wind Turbine Technology by Ahmad Hemami.

  • Abrasion - Wear in machinery between components grinding against each other
  • Active yaw - Having controlled yaw motion rather than forced motion through wind
  • Aerodynamic Force - Force exerted by moving air or gas
  • Airfoil - Profile of the outline of an airplane wing, usually having large lift coefficient and a small drag coefficient
  • Alignment - Having the axes in a straight line
  • AC - Alternating Current, type of electricity with continuously alternating direction
  • Alternator - machine generating AC electricity
  • Amplitude - instantaneous value of cyclic variable
  • Anemometer - windspeed measuring device
  • Angular speed - rotational speed of an object in radians/sec or degrees/sec
  • ANSI - American National Standards Institute
  • Arc Flash - flow of electricity outside a conductor caused by a short circuit, generates high pressure and temperature in the air
  • Arm - Part of a planetary gear that holds the planet gears together
  • Armature - Rotating part in a motor, composed of one or more windings
  • ASME - American Society of Mechanical Engineers
  • Asynchronous Generator - aka induction generator
  • Autotransformer - transformer where primary and secondary windings are part of the same winding, not isolated
  • AWEA - American Wind Energy Association
  • Backlash - free motion between two meshing gears due to noncontact free space between teeth
  • Balanced Load - When three loads in a three-phase electrical system have equal values
  • Bedplate - A main structure in a nacelle where all the components are mounted or attached
  • Betz Limit - Maximum value of a wind turbine's power coefficient. 16/27 or 0.59
  • Bevel Gear - Gears with perpendicular axes
  • Blade Pitch Control - The capability of turning a turbine blade about its axis with respect to its hub
  • Blade Root - attachement of blade to hub
  • Blade Tip - free end tip of blade
  • Bridge Rectifier - full rectifier where two sets of diodes alternatively conduct, converts AC to DC
  • Brush - part of carbon in an electric machine that slides on a conductor to allow for electricity transfer between moving components to stationary components
  • Cable Grip - Metallic device for turbine climbing
  • Capacitive Reactance - Apparent resistance due to a capacitor
  • Carabiner - Metallic device allowing connection of two rings in climbing equipment
  • Carrier - Part of a planetary gear holding gears together called arm
  • Cavitation - An interaction between metallic rotating piece and a liquid in a gearbox or pump causing erosion
  • Centrifugal force - Outward force due to rotating reference frame
  • Characteristic Curve - Curve exhibiting the main features of a device machine or equipment based on a major parameter
  • Characteristic Diagram - aka Characteristic Curve
  • Chord - Distance between leading and trailing edge of airfoil
  • Chord Line - line connecting leading and trailing edge of an airfoil
  • Collector - Point where turbine outputs in a windfarm are connected before being sent to grid
  • Compound Interest - Periodically increased interest
  • Cone Angle - angle that blades of a wind turbine make with plane perpendicular to axis of rotation
  • Corrective Maintenance - fix components after it breaks rather than preventative
  • Cost of Capital - Money spend to generate capital for investment
  • Crowbar - Set of resistors that come into operation when generator disconnects and load vanishes, prevents overspeed
  • Current - Intensity of flow of electrons in Amperes
  • Line Current - Current in supply lines of three-phase electrical system
  • Current Direction - Direction of electrons in a current
  • Cut-in Speed - minimum speed for a turbine to generate power
  • Cut-out Speed - maximum speed for a turbine to generate power
  • Darrieus Turbine - Vertical axis wind turbine looks like eggbeater
  • Delta Connection - Connects three wires of three phase electricity to a load in a triangular formation
  • DFIG - Doubly fed induction generator where the rotor is made of windings and requires slip rings to connect to electricity
  • Diode - Semiconductor with two terminals, allows one way curent
  • DC - Direct Current type of electricity that flows in one direction
  • Direct Drive Mode - Connecting a turbine and generator without a gearbox
  • Discout Rate - economic term implies rate for borrowing money
  • Dispatch System - communication system where all participants are informed
  • Distribute Generation System - Electrical system with more than one generator, typically referring to many small sets of generators as opposed to centralized larger ones
  • Downwind Turbine - Turbine where wind hits tower before blades
  • Drive Gear - transfers energy to mating gear
  • Drag - component of aerodynamic force parallel to wind that slows down movement
  • Drag Coefficient - ratio of drag force to aerodynamic force causing it
  • Drag-Type Turbine - turbine based on drag forces
  • Drive Train - set of gears to obtain desired gear ratio
  • Dynamo - Direct Current Generator
  • Efficiency - Ratio of output energy to input energy
  • Electric Circuit - setup of electrical components powered by a source
  • Electric Load - consumer of electricity
    • resistive - load that has only resistance
    • capacitive - load consists of capacitors
    • inductive - contains windings
  • Electric Source - battery or generator providing power to a system
  • Electromagnet - magnet made of coil and ferromagnetic core, requires electric power for magnetism
  • Electromechanical System - Device with both moving and electric parts
  • Energy - Potential to do work, or force applied over a distance
  • Epicyclic Gear - Planetary Gear
  • EWEA - European Wind Energy Association
  • Fall Arrest - Stopping a fall from a height
  • Fatigue - repeated tension/compression stress
  • Fatigue Failure - failure of component due to fatigue
  • Feathered - Position of wind turbine blades with smalles lift and largest drag
  • Ferrous - Iron family of metals
  • Fixed Speed Mode - Turbine speed constant operation
  • Flashing - repeated reflection of sunshine on a turbine blade
  • Flicker - Short time voltage variation in power line due to disconnect of large load
  • Flickering - Shadowing effect of rotating blade
  • Flutter - Vibration of wind turbine blade about its own axis
  • Foundation - Massive block of concrete anchoring a tower
  • Free Wheel - Standby state of wind turbine where there is insufficient wind to turn turbine
  • Frequency - Number of repetitions in one second of cyclic phenomenon
  • Frequency Converter - Device that changes frequency of AC
  • Full-Wave Rectifier - 2 rectifier diodes that converts the entire cycle of AC to DC
  • Fuse - Protection device in electrical circuit that melts to open a circuit in the case of overheat
  • Future Value - value of money at future time
  • Gearbox - mechanical device in an enclosure, converts rotational speed
  • Gear - single part of gear system, gearbox component
    • Arm - part of planetary gear that holds the planetary gears together
    • Bevel - perpendicular axes connected gear
    • Driven Gear - receives energy from mating gear
    • Driving Gear - gives energy to mating Gear
    • Epicyclic Gear - Planetary Gear
    • Helical Gear - teeth are angled with respect to shaft axis to reduce backlash
    • Idler Gear - gear that stands in between two main gears to change direction of rotation
    • Internal Gear - gear in the form of ring with teeth on the inside
    • Planetary Gear - set of gears arranged in form consisting of sun gear in the middle, usually 3 planetary gears engaging with sun gear and outer ring gear with internal teeth, can accept two input speeds, mounted on bracket that can turn independently
    • Ring Gear - outermost gear with internal teeth in planetary gear
    • Spur Gear - gear with teeth parallel to axis of rotation
    • Sun Gear - innermost planetary gear
    • Worm gear - gear with high ratio to reduce speed, axes set at 90 degrees
  • Gear Ratio - ratio between output and input speeds in a set of gears
  • Gear train - set of gears arranged to obtain a specific gear ratio
  • Generator - machine that produces electricity, mechanical to electrical
    • Armature - windings on the rotating part in a generator or motor, current carrying windings on a moving part
    • Brush - electrical connector made of carbon or carbon composite, when electrical connection between rotating and stationary parts needed, slides on metallic rotating ring
    • Rotor - rotating part of generator
    • Stator - stationary part
  • Grid - Electric Network
  • Half-wave Rectifier - Simplest type of AC to DC rectifier one diode only accounts for half the wave transferred into DC
  • Harmonics - frequencies that are multiples of the fundamental frequency
  • Harness -  part of the protective equipment or catching the wind energy by a turbine
  • HAWT - Horizontal Axis Wind Turbine
  • Hertz - frequency unit
  • High-Speed Shaft - Output shaft in a wind turbine linked to generator shaft
  • HVDC - High Voltage Direct Current transmit electricity around 300 kV DC
  • Hub - part of propeller type wind turbine to connect blades
  • Ideal Transformer - Assumed transformer with zero loss
  • IEEE - Institute of Electrical and Electronics Engineers
  • Induction Generator - AC generator where rotor current is generated by induction than connection to electricity as in the synchronous generator
  • Inductive Reactance - Apparent resistance due to an inductor
  • Inertial Force - force required for acceleration or deceleration
  • Infrasound - sound with frequency below human hearing sometimes generated by wind turbines
  • Initial Cost - startup costs of a project
  • Inverter - converts DC to AC electricity
  • Islanding - isolation of a part of AC Network from rest resulting in frequency and voltage drift
  • ISO - International Standards Organization
  • Isolation Transformer - Transformer used to separate a circuit from the main device 
  • Kilowatt - a thousand watts
  • Kilowatt-hour - measures energy consumption
  • Kinetic energy - energy associated with motion
  • Lagging - current waveform behind the voltage waveform
  • Lanyard - part of safety equipment hooked to a safe point for fall arrest, contains spring piece
  • Lattice Tower - tower made from small pieces welded together into a truss
  • Leading - current waveform in front of voltage waveform
  • Lift - perpendicular aerodynamic force to direction of wind caused by pressure differential over an object
  • Lift Coefficient - ratio of lift force to aerodynamic force causing it
  • Lift-Type Turbine - turbine based on lift instead of drag
  • Lockout - locking a dangerous device from normal use
  • Lorentz Force - Force exerted on wire carrying a current inside Magnetic Field
  • Main Shaft - low speed shaft in gearbox connected to rotor
  • Maintenance - keeping a machine in operation
    • corrective - repair after failures occur
    • preventative - systematic repair regardless of state of machine
    • scheduled maintenance - regular planned repair
  • Met Tower - Meteorological Tower
  • Motor - converts electrical energy to mechanical
  • Nacelle - A room at the top of a turbine tower that houses gearbox, generator and other equipment
  • Natural Frequency - frequency inherent to object that can resonate
  • Net Present Value - economic term represents current revenues minus the total cost over lifetime of project
  • Offshore - on a lake or sea
  • Onshore - on land
  • Operating Costs - continuous expenses necessary to run endeavor, such as rent, purchase of raw materials, maintenance
  • Operating Speed - speed at which machine normally works
  • OSHA - Occupational Safety and Health Agency
  • Output - Product or result of a machine
  • Overspeed - Speed above entire capacity potentially dangerous to machine
  • Pad Mount - transformer mounted on flat surface
  • Peak Hours - Electricity consumption peak hours
  • Permanent Magnet - Magnet that is continuous without electrical input
  • PPE - Personal Protective Equipment
  • Phase Angle - angle between voltage and current waveform, time delay
  • Phase Current - Current passing through a load between each of two lines in 3 phase system
  • Phase voltage - voltage across each individual load in 3 phase system
  • Pinion - smaller gear in a pair of gears or the output gear in drive train
  • Pitch Angle - angle blade forms in reference to rotation about its axis, alters angle of attack
  • Pitch Circle - represent gears size
  • Pitch Control - action of controlling pitch angle of blades
  • Pole Mount - transformer mounted at top of electricity distribution post
  • Power - Work done in 1 second
    • Active - Power converted to heat or work
    • Reactive - power due to capacitor or inductor storage in one part of cycle given back in next part of cycle
    • Apparent - power generator supplies for consumption
    • Coefficient - in wind turbine must be less than Betz Limit ratio of electrical generation to what is in the wind
    • Curve - Operational expected power curve
    • Factor - ratio of active power to apparent power, smaller than 1
    • Factor Correction - improving the power factor of AC currents using capacitors
    • Plant - industrial unit for generation
    • quality - degree of agreement to expected stability requirement, 50 or 60 Hz
  • PPE - Personal Protection Equipment
  • Present Value of Money - value of money expressed for a future time in today's money
  • Prevailing Wind - Most common wind direction for an area
  • Prime Mover - Source of mechanical power turns a generator
  • Propeller Turbine - Turbine with blades similar to propeller, most common type of wind turbine
  • Rectifier - converts AC to DC
  • Renewable Energy - Energy from natural sources that is recoverable
  • Reluctance Force - Force by an electromagnet trying to shorten path of magnetic field
  • Ripple - Rapid fluctuations of voltage about nominal value in DC
  • Root of a Blade - end of blade attaching to hub
  • Rotating Magnetic Field - Magnetic field rotates about an axis, exists inside the stator of AC motors, basis of their operation
  • Savonious Rotor - drag type turbine that consists of two half cylinders
  • Scuffing - transfer of metal particles by tearing and adhesion from one tooth in a gear to another by welding
  • Shadow Flicker - Moving shadow cast by rotating blade
  • Shear Stress - stress due to a cutting force
  • Sine Wave - Sinusoidal wave function
  • Single - Phase - simplest AC electricity transmitted by 2 wires
  • Skew Wind - Wind whose direction is very far off from horizontal
  • Slip - act of not rotating at synchronous speed in induction motors and generators
  • Slip Ring - metallic ring on rotor of certain types of AC machines to transfer electric current
  • Slip Speed - difference between actual rotating speed and synchronous speed
  • Smart Grid - grid equipped with automated self correcting devices
  • Solidity - percentage of solid area traced in a circular rotor motion, blade area to total area
  • Spar Platform - platform in the form of a vertical cylinder top for wind turbine
  • Squirrel-Cage Motor - induction motor without windings, consists of bars connected by two rings, cage like structure
  • Stall - decrease in lift force until drag takes over
    • Control - use of stall to regulate motion of turbine
  • Star connection - connect wires in a y shape as opposed to a triangular shape
  • Step-down - lowering voltage
  • Step-up - increasing voltage
  • Substation - electrical utility to regulate electricity before sending to grid
  • Synchronous Generator - AC generator with one or more magnets, electricity generated in stator when rotor rotates at a fixed frequency
  • Synchronous Motor - AC motor where one or more magnets is within a rotating magnetic field causing rotor to follow the field, runs at multiples of synchronous speed
  • Synchronous Speed - constant speed of electrical machine dependent on frequency of supply
  • Tagout - put note on device or location as safety precaution
  • Tension Leg Platform - floating platform kept in place by cables attached to seabed under tension
  • Three-Phase System - requires 3 wires at least, each with fixed delay between them in voltage
  • Thyristor - control transistor used in rectifiers and inverters
  • Tip Speed - speed of tip of blade
    • Ratio - ratio of tip speed to wind speed
  • Torque - turning effort about a point perpendicular to rotational motion
  • Tower - support rotor and nacelle
    • Lattice - welded small structure support
    • Tubular - singular tube or conic shape support
  • Turns Ratio - ratio between number of turns in primary and secondary windings
  • Universal Motor - Type of motor that can work with both DC and single phase AC
  • Upwind Turbine - Wind turbine where blades are in front of tower and wind reaches blades before tower
  • Variable Slip Mode - Way of operation where wound rotor induction generator used with some power extracted
  • Variable Speed Mode - Synchronous generator that can operate at different instead of singular speed
  • VAWT - Vertical Axis Wind Turbine not sensitive to wind direction changes
  • Vector - quantity with both magnitude and direction
  • Volt - Electrical potential
  • Volt-Ampere - unit of measurement used to express apparent power, when voltage and current out of phase
    • VAR - Volt Ampere Reactive - measures reactive power
  • Watt - 1 Joule per second
  • Wind Data - Statistical information gathered about wind in a region
  • Wind Farm - region of multiple wind generators also called wind park
  • Wind Vane - measures wind direction
  • Work - used energy
  • Worm gear - high gear ratio used to reduce speed, driven gear cannot force drive gear to rotate
  • WRIM - Wound rotor induction machine whose rotor contains winding instead of squirrel cage
  • Wye Connection - also called star connection
  • Yaw - action of orienting a wind turbine into direction of wind
  • Yaw Gear - gear system to rotate turbine for yaw motion
  • Yaw System - Entire gears and motors involved in Yaw motion of turbine

Saturday, December 1, 2012

Notes - Chapter 17 Summary

The following notes are taken from Wind Turbine Technology by Ahmad Hemami.
  • Hazards
    • height
      • most serious threat, fatalities in 2008 due to falls was 700 in US
    • confined environment
    • electrical equipment
    • turbine motion
  • Accidents usually due to lack of knowledge and ignoring safety rules
    • training for safety should be provided
    • responsibility of the employer to provide safe environment
  • Safety Regulations set and monitored by authorities in each country
    • (OSHA) Occupational Safety and Health Administration
  • Safety number one
    • (PPE) Personal Protection Equipment used to reduce risk of accidents
      • must be checked periodically, i.e. yearly inspection
      • climbing gear
        • simplest includes harness to wear, cable grip, locking carabiner
      • hard hat
      • fall arrest equipment
        • lanyard with a hook to secure to a point
    • Tagout and lockout practice
      • tagout is a note to notify about dangers
      • lockout place equipment to be confiscated
    • Receive training for self rescue
    • worker learns how to rescue colleagues
  • Long sleeve shirts and pants, no unnecessary accessories

Notes - Chapter 16 Summary

The following notes are taken from Wind Turbine Technology by Ahmad Hemami.
  • Turbine must operate in a safe state
    • clean dirt, oil and leftovers of any kind
    • account for effects in temperature
      • first components affected are gearbox and lubrication oil
    • Account for formation of ice on the blades
      • brings up hazards when the ice melts and flies off blades
      • greater during startup or shutdown
  • Subject to getting struck by lightning
    • can cause severe structural damage
    • equipped with lightning rod from tip to root
    • embed in blade structure from tip to root, connect to hub and nacelle and down tower
  • Wind turbines have the potential to be used in urban areas
    • not propeller turbines, vertical axis ones more likely
    • safe, quiet, and non obstructive, likely on the top of buildings
    • economically viable and worth endeavor

Notes - Chapter 15 Summary

The following notes are taken from Wind Turbine Technology by Ahmad Hemami.
  • It is important to know the possible effects on the environment
  • main reason for offshore wind farms are environmental concerns
  • Turbines
    • causes sound pollution, characterized by frequency
    • Infrasound is low frequency, not audible by humans
    • turbine is far enough that we cannot hear it, it does not have adverse sound effects
  • Obstructs View
  • Modern Turbines also constructed for aesthetics to eliminate view complaints
  • Flashing is the cyclic reflection of sunshine on turbine blades
  • Flickering is the cyclic moving shadow cast by turbine blades
  • Birds and Bats can be slain by turbine
    • less than deaths caused by house cats so not often complained
  • A wind farm must not be developed where the ecosystem of natural habitants can be disrupted
  • Wind Farms can also interfere with communications depends on the location of turbines and transmitters
  • Offshore wind turbines about 30-40 miles out to sea
    • Electricity distribution requires cables to be installed under the seabed
    • HVDC High Voltage Direct Current preferable for offshore wind farms but more expensive
    • shallow water can be fixed to seabed, deep water must be floating

Notes - Chapter 14 Summary

The following notes are taken from Wind Turbine Technology by Ahmad Hemami.
  • Value of money is not constant due to inflation and other factors
  • In order to evaluate, net income must be calculated based on full life of the project
    • reflect all income, cost, and investment
    • Future value of money dependent on interest rate and inflation
  • Profitability important for development
  • Cost of developing wind farm has high initial and operating costs
    • initial costs are the expenses that must be paid up front
      • high in comparison to other generation sources
    • operating costs paid throughout lifetime
      • annual expenses generation and delivery operations
      • smaller in comparison to other generation, no fuel
        • proper maintenance can also reduce this price
        • preventative maintenance helps ensure more evenly distributed costs

Notes - Chapter 13 Summary

The following notes are taken from Wind Turbine Technology by Ahmad Hemami.
  • The wind loads on all parts of a turbine ultimately transferred to the ground
  • Each component must be strong enough to withstand their loads
    • dependent on turbine rpm, and wind
    • do not diminish when turbine is at rest, only changed
    • Aerodynamic forces are top heavy, so the blades and rotors are subject to periodic forces
    • Frequency of these forces is 3 times the speed of rotation
  • Natural frequency is an intrinsic property of any mechanical component with flexibility
    • each blade, hub structure, main shaft, tower are principle components that contribute to natural frequency
    • natural frequencies must not be able to excite one another
    • blade in particular and any other turbine components under cyclic loads are subject to fatigue
    • vibration is undesirable, causes early failure in components

Notes - Chapter 12 Summary

The following notes are taken from Wind Turbine Technology by Ahmad Hemami.
  • Transformer is a necessary electrical device for any wind turbine
    • steps up the voltage from generator to the collector for the grid
    • Transformers either step up or step down voltage and are called as such
  • If transformer is not used to change voltage, it is used to protect a device and is called an isolation transformer
  • Ideal transformer is used for calculations, assumes no losses so output power equals input power
  • turns ratio
    • ratio of windings between winding 1 and winding 2
  • Autotransformer has only one winding for input and output, tapped for electricity at variable location
  • pad-mount transformer is mounted on flat surfaces, pole mount on poles
  • Rectifiers convert AC to DC
    • bridge rectifier, single phase or three phase
    • low power uses diodes
  • Ripples in DC is the fluctuation of voltage about a nominal value instead of being constant
  • Inverters provide AC voltage from DC source
  • Thyristor is a component used in rectifiers and inverters used for switching

Notes - Chapter 11 Summary

The following notes are taken from Wind Turbine Technology by Ahmad Hemami.
  • Direct Current generators only used in small isolated turbines
    • Electricity can be stored in batteries
    • Direct drive is when a generator is directly connected to turbine without gearbox
  • Motor and Generator have the same structure
  • Industrial Turbines always use three-phase alternating current generators
    • Synchronous Generators
      • must operate at the synchronous speed
      • fixed speed mode and variable speed mode
    • Asynchronous Generators
      • also called an induction generator
      • squirrel cage generators, run in only one mode of operation
      • wound-rotor induction generators
        • connect to outside circuit with slip rings and brushes
        • run in variable slip mode
        • turbines with doubly fed induction generators
      • don't run at synchronous speed
        • generators must run at slightly higher speed
        • motors run at a slightly lower speed