5.1 DIRECTION CONTROL:RATCHETS:
A rached is a mechanism that controls the direction of motion.Some ratchets are reversible,so they can turn and lock in one direction or another.

5.2 SPEED REDUCTION:BRAKES:
Brakes use friction to reduce speed.They are activated by certain levers.The lever transmits forcé to an output receptor,which puts pressure on the Wheel.There are various types of brake systems according to where the friction is produced:

• Disc brakes:A disc is connected to an axle.Brake pads apply pressure to the disc.
• Band brakes:A drum is connected to an Axle.A flexible band applies pressure to the outside of the drum.These brakes were used in carriages and they depended on the strength of the driver.
• Drum brakes:A drum is connected to the axle.A pair of brake shoes apply pressure to the inside of the drum.
   
  
  

Cam mechanisms:A cam is an irregularly shaped device that rotates on a shaft.When the cam rotates,it pushes a special bar called a follower.The follower can move other parts or it can turn a switch on and off.Some cams are circular,but with an axis of rotation that is off-centre.These are called eccentric cams because they rotate in an irregular or eccentric way.

Crankshaft mechanism:We can multiple rods to one shaft.The rods are connected to cranks,and the cranks are connected to the crankshaft.A crankshaft mechanism can synchronise the movements of various parts,such as the multiple pistons of a car engine.

4.2 RECIPROCATING ROTARY-LINEAR TRANSFORMATION:
The pistons of a car engine produce into continuous rotary motion.Some mechanism work in the opposite way,transforming rotary motion into reciprocating linear motion.

Crank and rod mechanism:The piston moves a rod forwards and backwards.This rod turns the first Wheel.The second Wheel turns becouse it is connected to the first Wheel by another rod.

4.1 ROTARY-LINEAR TRANSFORMATION WHEEL:
they let us move more easily because they reduce our contact with the ground and decrease friction. However,if there isn't enoungh friction, the wheels can slide out of control.
With each rotation, a Wheel moves forward a distance that is equal to its circumference.As a result,we need less force to move vehicles with larger wheels and they move more quickly.

Rack and pinion mechanism:The rack is a bar with many teeth and the pinion is a gear with teeth that interlock with the rack. When the pinion rotates,the rack moves in a linear direction.

Nut and bolt mechanism:A bolt or shaft with a spiral Groove and a nut that turns around it.We can turn and lighten the nut in order to hold things together.We can a use a nut and bolt mechanism to lift loads because it fuctions as a reducing system.

Winch and crank mechanism:A winch is a cylinder that rotates around a horizontal axis.Then we turn the crank to rotate the winch.The rope rolls up around the winch and lifts the load.The crank increases the force and the winch transform rotary motion into linear motion.The increase in force is proporcional to the ratio between the radius of the crank and the radius of the winch.

F*d=R*r

3.5 WORM DRIVE:
A worm drive has two parts: a worm shaft and a worm gear. The shaft has two, three or even more grooves.Each Groove interlocks with one tooth of the worm gear.

Worm drive:

3.3 BELT DRIVES AND GEAR TRAINS:
A belt drive is a system of pulleys connected by belts.Each belt connects pair of pulleys,so they turn together.
To understand how a belt drive Works,we can analyse the example above:

• Wheel 1 turns Wheel 2,which moves faster because it is smaller.The size ratio between the wheels is D1/D2=1.5. If Wheel 1 makes 1 rotation,wheel 2 makes 1.5 ratations.
• Wheel 2 and Wheel 3 are connected to the same axis,so they turn together. If Wheel 2 makes 1.5 rotations,wheel 3 also makes 1.5 rotations.
• Wheel 3 turns Wheel 4,which moves faster becouse it is smaller.The size ratio between the wheels is D3/D4=2. If Wheel 3 makes 1.5 rotations,wheel 4 makes 1.5*2=3 rotations.

to calculate the ratio of transmission between the first Wheel and the last Wheel of a belt drive,we must multiply the ratios of transmission of the first pair of wheels and the second pair of wheels:

• N4/N1=D1*D3/D2*D4

3.4 CHANGES IN DIRECTION AND ROTATION:
We can use various system to change the direction of rotation or the axis of rotation in a belt drive.We can also vary the distance between the wheels.With belts,we can change the direction of rotation and the axis of rotation quites are more precise and they transmit more rotary force,or toque.

Parallel Axes:

Pendicular axes:

Crossed axes:

 

 

 

3.1 CHANGES IN SPEED:
The opposite is true if we want to decrease the speed of a rotary system.We must transmit motion from a smaller element to a larger element.If the input and output elements are the same size,the rotary speed remains constant.The rotary force will also remain constant.

• pulley1: D1)D2   N2)N1

• pulley1: D1=D2  N2=N1

• pulley1: D1(D2  N2(N1

3.2 SPEED RATIOS:
D1=30mm 
D2=10mm

 
  


 The relationship between the speeds of the two wheels is inversely proportional to their sizes.  
N2/N1=D1/D2
This relationship is called the ratio of tranmission,where N is the speed of rotation and D is the diameter of the wheel.  

3.ROTARY TRANSMISSION:
Rotary tranmission system put two rotating elements into contact.These mechanisms have two purposes:

• Friction wheels:  

• Pulleys with belts: 

• Interlocking gears:

All of these mechanisms keep the same speed retios,but each one offers a different advantage.
uses:friction wheels and pulleys are often used intoys and other devices with moving parts,such as industrial rollers or conveyor belt systems.Gears are used in clocks,while sprockets and chains are common in home appliances.

COMPOUND PULLEY SYSTEMS:
A compound pulley systems is a combination of fixed and movable pulleys.It is also called a block and tackle system.The more pulleys there are,the less force we need to lift the load.We can combine the pulleys in various ways.

• VERTICAL SYSTEM: 
  
  
  
  
  HORIZONTAL SYSTEM:

EXPONENTIAL SYSTEM:

2.2 PULLEYS AND COMPOUND PULLEY SYSTEMS:
In a system of pulleys,the equilibrium between the forces depends ion the parth that the rope follows.

PULLEYS:
Fixed pulley:the forces are equal because the rope moves the same distance on both sides.We can use gravity and our own weight to help us.It´s easier to lift a weight by pulling down than by pulling up.

 Movable pulley:the rope follows a double path around the pulleys.We need half the force to lift the same weight as with a fixed pulley.We must pull twice as much rope to lift an object to the same height.

 

BRAKE LEVERS:
Bicycle brakes decreased speed.

A HAND CRANK:
A clank is a class2 lever,so it obeys the law of the lever
F-is the force that we apply
D-distance from the axis of rotation
R-in the shaft.

BICYCLE HANDLEBARS: 
If we put our hands near the middle,it´s more difficult to turn the handlebars.It is easier to turn a larger steering wheel becouse there is a larger distance between the outside of the wheel and this axis of rotation in the centre. 

 

2. LINEAR TRANSMISSION OF MOTION:
Linear transmission mechanisms,such as pulleys,use linear motion inut to produce linearmotion output.

2.1 LEVERS:
A lever is a rigid bar that turns around a point called a fulcrum.
Each force prodeces a specific torque,which is the force multiplied by its distance from a fulcrum.
 When the forces acting on opposite ends of a lever are equal,we say the lever is in equilibrium.We can express this mathematically as the law of the lever.

                         F+d=R+r


CLASSES OF LEVERS:
We can divide levers into classes according to the locations of the fulcrum,force and resistance.

Class2:levers increase the fore that we apply
Class3:levers incrase the distance that the end of the lever moves.
Class1:levers can do both of those things.

 

TEMA 5

1.0 WHAT IS A MECHANISM?
The moving parts of a bicycle are examples of everyday mechanisms that make life easier and more enjoyable:

• The chain of a bicycle transfers motion to the back wheel
• The bar of a seesaw forms a lever that we can use for fun
• The gears inside old-fashioned clocks let us measure time
• The pulley systems above a well helps us to bring up later

They make work easier because they transmit and transform force and motion.All of these mechanims require an input force and motion from some type of source.In the case of a bicycle,our leg muscles are the input source.Mechanims transmit motion and force to receptors that finally perform the work.This is the output force nd motion.In the case of an analogue clock,the output receptors are the hands of the clock that move in circles to show the time.

1.1 THE PARTS OF A MECHANISM:

Mechanisms transmit and transform force and motion from an input source to an output receptor.This transmission and transformation lets us perform different types of work with more comfort and less effort.

Imput of force and motion.-----Mechanisms------Output force and motion.

7.USER LICENCES:
The informations and software that we find online may be protected by some form of license.Any software under this license is free software,which cannot be owner by anyone.Creative Commons Licenses allow us to give people certain rights for using content that we have created.You can get a CCL online if you fulfil the following conditions

6.EXCHANGING INFORMATION ONLINE:
It can be done quickly,easily and automatically by using Peer to Peer programs,such as Ares and BitTorrent.Althoungh many users exchange information online,we must be careful abaut the files and software that we download.There are legal restrictions that apply to many types of digital content.Other types of software are closed source,which means the source code can only be modefied by the progammer.
We can also differentiate between the following types of software:

• Free software:Anyone can use,modify,copy and distribute this software.It is also open source.
• Proprietary software:Users need special permission or a licence to use,modify,copy or distribute this software.
• Commercial software:The owner distributes and sells this software for a price.
• Freeware:This software does not cost anything.It can be copied and distributed,but it cannot be modified.
• Public domain software:The authors makes this software avaible to everyone at no cost.

5.3 WIKIS:
A wiki is a collection of a web pages that visitors can edit,modify or expand.In this way,the content grows quickly with the contributions of the people working on it.Normally,this would require paying for a hosting service,but many wikis use a free online service instead.
Adding new content to wikis page is quite easy:

1. Look for an edit button and click on it.
2. Make changes to the existing content or write a new contribution.
3. Look for a Save button and click on it to save the changes.

Many wikis offer open access to their Edit and Save fuctions.However,in some cases this access may be limited to avoid vandalism so that changes and additions must be approved by the original authors.

Wikipedia:

Is a universal encyclopedia with no restrictions on use,modification or redistribution.Wikipedia has grown in popularity and become one of the world's most visited websites.English is the mostly commontly used language.

In order of popularity,they are:

• German
• French
• Polish
• Italian
• Japanese
• Dutch
• Spanish 
• Portuguese
• Russian
• Swedish

Uploading a web page to a server:
If you are not using an online hosting service,you will need to upload your CMS program or your web page to the server.You can use FTP programs to upload your web page to the server.These programs manage the transfer of web page files from your computer's hard drive to a server.We call this uploading.FTP programs also work in the opposite direction,so you can download content from a server yo your computer.

Completing and updating a web page:
Remember that is the content is always up to date,people will continue visiting your web page.

5.2 BLOGS:
Weblogs or blogs are a special type of web page.They were originally used as online diaries for people to share their personal experiences.Bloggers publish entries or posts in chronological order,with newer posts appering at the top of the list.
Blogs have other characteristics which made them interesting:

• The same blog can be shared by various bloggers working together as a team.
• Blogs can include hyperlinks to photos,audio recordings or videos.
• We can use blogs to make daily reports abaut a project and receive helpful feedback from other people.
• Businesses can use blogs to improve their customer service,by quickly responding to questions or complaints abaut their products.They can also post manuals,videos and up-to-date information for their customers.

Some of the most popular blogging services are Blogger,Wordpress and Tumbr.

CREATING YOUR WEB PAGE:
We will look at various techniques,in order of complexity,from the most difficult to the simplest.

1.Direct programming:
Is the most difficult option,since it requires knowledge of programming languages and tools.

• HTML:Is used for stactic web page design.HTML was the first language invented for web page creation.
• CSS:Is used to create the structure of a document.
• PHP:Is a language used to create dynamic web pages.
• MySQL:Is a database management system used for dynamic web pages.

2.Using a Content Management System:

We can use a CMS to create dynamic web pages.

These systems have several advantage:

a) They are fast because they don't require direct programming.

b) Some are free.

c) Some CMS services offer a package that includes hosting and CMS installation.This is convenient because the installation sometimes requires special server functions.

There are also some disadvantages:

a)You cannot do anything you want.You are limited to the functions that the program allows.

b)CMS programs are complex and it takes a long time to learn how to use them.

c)You must have a server with enough storage space for the program.

The most popular CMS services are joomla!,Drupal and Wordpress. You can also use Prestashop to create a web page for online shopping.

3.Using a web development program:
These programs translate your web page design into HTML language,so you do not need to know how to program.Some are free,such as Kompozer. Others cost money,such as web creator and adobe dreamweaver professional ,which is the best-know.

4.Using the online hosting services that some pages offer:
This is the easiest way to create a web page.You select the elements of your web page from a menu of options and add them to one of the many templates that are offered.
These web creation services are quite complete and the results are very professional.The free versions have certain limitations:

a)They include advertising,which some people may find unattractive.

b)The web address may be rather long and difficult to remember.

Althoungh there are many services like this,the most popular ones include Wix,Jimdo,Hostiner and 1&1.Another popular web creation service is Google Sites.If you have a gmail account,you can easily create pages with web address such as the following:
https://sites.google.com/site/NAME_OF_YOUR_PAGE.

    HYPERLINKS:
Hyperlinks can be added to images or texts.There are two types of hyperlinks:

1. External links: Take use to other websites related to the topic.
2. Internal links: Take use to a different part of the same website.There may be forward or backward buttons,or an index at the beginning of the page with links to various sections of the text.

     VISUAL IMPACT:

1. Another fundamental aspect of web page design is the affective combination of text formats and images.
2. If we want our web page to look more dynamic,we can add animated gifs,which are images that move.We can also use dynamic text formats,which change their colour or appearance.

     COMMENTS FROM USERS:

Althoungh you shouldn't give any personal information on the internet,it may be interesting to receive feedback from users who visit your page.

       PAGE ORDER:

If you have created various pages,you can join them together with internal links.Here are two ways that you can order the pages.

1. Linear order:One page follows another,like the pages of a magazine.
2. Hierarchial order:From the first page,we can link to any other page that we like.

5.0 CREATING INFORMATION:
On the internet, we can quickly and easly creaty information about anything that we consider interesting.Then we can communicate that information to other people,either privately or publicly.The most popular tools for creating and distributing information on the internet are web pages,blogs and wikis.

5.1 WEB PAGES:
In the following section,you will learn how to create attractive web pages where you can share information with other people.The first step is to plan the design and content of everything that will appear on your web page,such as text,photos and illustrations.The content must be interesting and visually appealing in orden to attract the maximum number of visits.The steps that you must follow are:

1. Register a domain
2. Sign up with a host server
3. Design and create your web page
4. Upload your page to the server
5. Update your web page regularly

DOMAIN NAMES:

To register a domain for your web page,you must choose a name that is not alredy being used.Domain registration services have seach engines for checking possible names.

HOST SERVERS:

Web pages by offering space on their servers.Domain registration services may also provide hosting,and web page design companies often include both registration and hosting.The cost of hosting usually depends on the amount of space that your domain will occupy on the server.

DESIGNING AND CREATING A WEB PAGE:
A website is a set of web pages under the same domain name.
Designing a web page:there are no official rules for how a web page must look.
Title:the title that you choose is very important,since it indicates the overall topic of your web page.The title will be used to match your page with other people's seach criteria.The title of a web page also appears in the banner section of a web browser.
Colour combinations:You should remember this when you choose text and background colours for your own web page.
A baladed layout:To archieve this effect,we can use tables to structure the in neat columns and rows.In addiction,tables allow 
for other functions:

1. Inserting and eliminating rows and colums.
2. Combining and dividing cells.
3. drawing borders on cells and tables.
4. Changing the background and text format of each cell.

4.2 VERTICAL SOCIAL NETWORKS
The users of vertical networks form communities who have similar reasons for using the application.These reasons,witch can be personal or professional,may incluide:

1. SHARING PROFESSIONAL INFORMATION:  Linkedln is the most popular network for all kinds of professionals.
2. SHARING GENERAL INFORMATION:  With FriendFeed,people can create private groups to share information abaut projects,organise events and exchange photos or experiences with their friends.
3. SHARING PHOTOS:  Instagram,Flickr,Pinterest and Picassa are popular.
4. SHARING VIDEOS:  Youtube,Dailymotion and Vimeo are common examples.
5. LIVE STREAMING:  Skype,Twith,Livestream and Upstream are often used.
6.  there are many other services related to sports,cinema,books and other topics.

4.0 SHARING INFORMATION
Social networks have revolutionised how we spread or share information.We can define social networks as virtual environments for communications,interaction and the sharing of resources.They can be divided into two groups:horizontal or general social networks and vertical or thematic social networks.

4.1 HORIZONTAL SOCIAL NETWORKS
The users of horizontal networks form communites who have diverse interests and a wide variety of reasons for using the application.The most popular are:

1. FACEBOOK:

This application allows groups of friends to publish both public and private messages with text,links,news,photos and videos.    

      2.TWITTER:

This social network has some anusual features.Users publish short text menssages(tweets) with no more than characters,which is called microblogging.One of the most interesting funtions is using hashtags to follow interesting events or topics.A twitter app is avaible for mobile devices.

      3.GOOGLE +:

this social network allows users to create circles of friends in order to share information.

      

3.2 WORKING IN THE CLOUD
Some internet services let us create,save and modify documents online.This is called 'cloud computing'. The most popular cloud-based services are GOOGLE DRIVE,DROPBROX and OneDrive,which are also available as mobile apps.The two main advantages of these services are:

1. Access to our files from any location or device with an internet connection.
2. The ability to share our files easily with other people.

In addition to storing and sharing information in the cloud,we can also use programs for word-processing,spreadsheets and presentations.

3.1 SOCIAL BOOKMARKING
Social bookmarking is an internet tool that lets us organise,use and share information more efficiently.It works in a way that is similar to the favorites option of a browser program,but with an extra adventage:All of our content is stored in the cloud so we can access it from any location in the word.some of the most popular social bookmarking applications are:

1.DELICIUS:
Is a service that lets us save our favorite web pages along with a description and a list of key words for aesier classification.We can share this information with other people and see the content that they have bookmarked.

2.DIIGO:
Defines itself as a multi-tool for knowledge management. Among other funtions,it lets us bookmark the pages that we visit and create a digital library in the could,with links,notes and images.We can access this library from any location and select the information we want to share.Diigo is also available for mobile devides.

3.EVERNOTE:
Provides a convenient workspace where we can collect information by capturing articles and images from the internet.Then we can add notes and share information with other people.The application also has a seach function for finding specific details in the content that we have saved.

2.0 FINDING INFORMATION:
The most common sources of online information are web pages and news feeds.

2.1 WEB PAGES:
A web pages is a collection of documents that can include text,audio,video,images and hypertext links to other web pages. A browser is a program that locates a web page by its address and lets users access the content. A search engige is a web page with a database of information abaut other web pages and their content.when we look for information online,it is very important to consult the web pages of companies,corporations or associations that we know and trust.we should also analyse the information to decide if it is true or complete.

2.2 NEWS FEEDS: RICH SITE SUMMARY:
Rich site summary is a subscription service that provides users with frequent updates from media websites,blogs and other sources of information.RSS news feeds are convenient and time-saving.Since subscribers receive the news automatically,they do not have to visit so many websites.

1. Directly from the web page,by clicking on a 'subscribe' icon.
2. Through a news aggregator program,such as Old Reader,RSS Reader or Netvibes.More modern programs,such as Feedly,can be downloaded to smartphones with Android or iOS operating systems.

TEMA 10

1.1 WEB 1.0,WEB 2.0, WEB 3.0

We are not only talking abaut the internet,we are also talking abaut the way that users participate in activities online.

WEB 1.0
It was a network of documents and people could not interact with the content.In addiction,the information online was not updated very frequently.Almost everything that people used online was also part of the World Wide Web(www).

WEB 2.0
In this new web, information became bidirectional.Users could not only receive information,but also create and share it.New services appeared and became popular,such as email,chats,videoconferences,forums,blogs,wikis and programs for person-to-person file exchange.Social networking was born.

WEB 3.0 
Cutting-edge developments formed the basis of technological evolution: artificial intelligence;applications that do not use a browser,such as smartphone apps;virtual realy;and Global Positioning System.These tools,which are explained in four sections,will be very useful to you in the futere.

1. Finding information.
2. Managing information.
3. Sharing information.
4. Creating information.

Hello my name is marga and this blog will explain different technologies. 

In this blog I go about doing summaries of the contents of different technological topics.