General understanding what is internet used for ответы
General understanding what is internet used for ответы
Text C: «INTRODUCTION TO THE WWW AND THE INTERNET»
Millions of people around the world use the Internet to search for and retrieve information on all sorts of topics in a wide variety of areas including the arts, business, government, humanities, news, politics and recreation. People communicate through electronic mail (e-mail), discussion groups, chat channels and other means of informational exchange. They share information and make commercial and business transactions. All this activity is possible because tens of thousands of networks are connected to the Internet and exchange information in the same basic ways.
The World Wide Web (WWW) is a part of the Internet. But it’s not a collection of networks. Rather, it is information that is connected or linked together like a web. You access this information through one interface or tool called a Web browser. The number of resources and services that are part of the World Wide Web is growing extremely fast. In 1996 there were more than 20 million users of the WWW, and more than half the information that is transferred across the Internet is accessed through the WWW. By using a computer terminal (hardware) connected to a network that is a part of the Internet, and by using a program (software) to browse or retrieve information that is a part of the World Wide Web, the people connected to the Internet and World Wide Web through the local providers have access to a variety of information. Each browser provides a graphical interface. You move from place to place, from site to site on the Web by using a mouse to click on a portion of text, icon or region of a map. These items are called hyperlinks or links. Each link you select represents a document, an image, a video clip or an audio file somewhere on the Internet. The user doesn’t need to know where it is, the browser follows the link.
All sorts of things are available on the WWW. One can use Internet for recreational purposes. Many TV and radio stations broadcast live on the WWW. Essentially, if something can be put into digital format and stored in a computer, then it’s available on the WWW. You can even visit museums, gardens, cities throughout the world, learn foreign languages and meet new friends. And, of course, you can play computer games through WWW, competing with partners from other countries and continents.
Just a little bit of exploring the World Wide Web will show you what a lot of use and fun it is.
World Wide Web — «Всемирная Паутина»
to retrieve — извлекать
variety — разнообразие, спектр
to share — делить
humanities — гуманитарные науки
business transactions — коммерческие операции
to browse — рассматривать, разглядывать
browser — браузер (программа поиска информации)
to provide — обеспечивать (чем-либо)
provider — провайдер (компания, предоставляющая доступ к WWW через местные телефонные сети)
broadcast live — передавать в прямом эфире site — страница, сайт
to link — соединять
to compete — соревноваться
General understanding:
1) What is Internet used for?
2) Why so many activities such as e-mail and business transactions are possible through the Internet?
3) What is World Wide Web?
4) What is Web browser?
5) What does a user need to have an access to the WWW?
6) What are hyperlinks?
7) What resources are available on the WWW?
8) What are the basic recreational applications of WWW?
Exercise 9.8. Which of the listed below statements are true/false. Specify your answer using the text.
1) There are still not so many users of the Internet.
2) There is information on all sorts of topics on the Internet, including education and weather forecasts.
3) People can communicate through e-mail and chat programs only.
4) Internet is tens of thousands of networks which exchange the information in the same basic way.
5) You can access information available on the World Wide Web through the Web browser.
6) You need a computer (hardware) and a special program (software) to be a WWW user.
7) You move from site to site by clicking on a portion of text only.
8) Every time the user wants to move somewhere on the ‘eh he/she needs to step by step enter links and addresses.
9) Films and pictures are not available on the Internet.
10) Radio and TV-broadcasting is a future of Internet. They’re not available yet.
Exercise 9.9. Define the following using the vocabulary:
2) World Wide Web
4) Internet provider
5) Hyperlinks
Exercise 9.10. Find the equivalents:
1) Объем ресурсов и услуг, которые являются частью WWW, растет чрезвычайно быстро.
2) Каждая ссылка, выбранная вами представляет документ, графическое изображение, видеоклип или аудио файл где-то в Интернет.
3) Интернет может быть также использован для целей развлечения.
4) Вы получаете доступ к ресурсам Интернет через интерфейс или инструмент, который называется веб-браузер.
5) Вся эта деятельность возможна благодаря десяткам тысяч компьютерных сетей, подключенных к Интернет и обменивающихся информацией в одном режиме.
6) Пользователи общаются через электронную почту, дискуссионные группы, чэт-каналы (многоканальный разговор в реальном времени) и другие средства информационного обмена.
Exercise 9.11. Match the following:
1) You access the information through one interface or tool called a.
2) People connected to the WWW through the local. have access to a variety of information.
3) The user doesn’t need to know where the site is, the. follows the.
4) In 1996 there were more than 20 million users of the.
5) Each. provides a graphical interface.
6) Local. charge money for their services to access. resources.
Words to match with:
1) web browser, providers, link, WWW,
Questions for group discussion:
2) World famous authors and publishers say that the Internet violates their copyright because Web-programmers put all kinds of books, pictures, music, films and programs free on the Internet and this reduces their sales and profits.
3) Has anyone in your group experience working on the Internet? Ask them 1) about the difficulties they had; 2) useful information retrieved; 3) fun they got? Why so few people have experience working on the Internet?
FAMOUS PEOPLE OF SCIENCE AND ENGINEERING
William Henry Gates was born in Seattle, Washington, in 1955.
He is an American business executive, chairman and chief executive officer of the Microsoft Corporation. Gates was the founder of Microsoft in 1975 together with Paul Alien, his partner in computer language development. While attending Harvard in 1975, Gates together with Alien developed a version of the BASIC computer programming language for the first personal computer.
In the early 1980s. Gates led Microsoft’s evolution from the developer of computer programming languages to a large computer software company. This transition began with the introduction of MS-DOS, the operating system for the new IBM Personal Computer in 1981. Gates also led Microsoft towards the introduction of application software such as the Microsoft Word processor.
Much of Gates’ success is based on his ability to translate technical visions into market strategy. Although Gates has accumulated great wealth from his holdings of Microsoft stock, he has been known as a tough competitor who seems to value winning in a competitive environment over money. Gates still continues to work personally in product development at Microsoft.
Text C: «INTRODUCTION TO THE WWW AND THE INTERNET»Текст C: «ВВЕДЕНИЕ В WWW И ИНТЕРНЕТ»
Миллионы людей во всем мире используют Интернет для поиска и получения информации по всем видам тем в самых разных областях, включая искусство, бизнес, правительство, гуманитарные науки, новости, политику и отдых. Люди общаются по электронной почте (по электронной почте), дискуссионным группам, чат-каналам и другим средствам обмена информацией. Они обмениваются информацией и совершают коммерческие и деловые операции. Вся эта деятельность возможна, потому что десятки тысяч сетей подключены к Интернету и обмениваются информацией одним и тем же основным способом.
World Wide Web (WWW) является частью Интернета. Но это не набор сетей. Скорее, это информация, которая связана или связана как сеть. Вы получаете доступ к этой информации через один интерфейс или инструмент, называемый веб-браузером. Количество ресурсов и услуг, входящих в состав Всемирной паутины, растет очень быстро. В 1996 году было более 20 миллионов пользователей WWW, и более половины информации, которая передается через Интернет, осуществляется через WWW. Используя компьютерный терминал (аппаратное обеспечение), подключенный к сети, являющейся частью Интернета, и с помощью программы (программного обеспечения) для просмотра или получения информации, входящей в состав Всемирной паутины, люди, подключенные к Интернету и Всемирная паутина через местных поставщиковимеют доступ к разнообразной информации. Каждый браузер предоставляет графический интерфейс. Вы перемещаетесь с места на место, с сайта на сайт в Интернете, используя мышь, чтобы щелкнуть по части текста, значка или области карты. Эти элементы называются гиперссылками или ссылками. Каждая выбранная вами ссылка представляет собой документ, изображение, видеоклип или аудиофайл где-то в Интернете. Пользователю не нужно знать, где он находится, браузер следует по ссылке.
Всевозможные вещи доступны на WWW. Можно использовать Интернет в рекреационных целях. Многие теле- и радиостанции транслируются в прямом эфире на WWW. По сути, если что-то можно поместить в цифровой формат и сохранить на компьютере, то оно доступно на WWW. Вы даже можете посетить музеи, сады, города по всему миру, изучать иностранные языки и встречаться с новыми друзьями. И, конечно же, вы можете играть в компьютерные игры через WWW, конкурировать с партнерами из других стран и континентов.
Просто немного изучите Всемирную паутину, покажут вам, что очень полезно и интересно.
Запас слов:
Millions of people around the world use the Internet to search for and retrieve information on all sorts of topics in a wide variety of areas including the arts, business, government, humanities, news, politics and recreation. People communicate through electronic mail (e-mail), discussion groups, chat channels and other means of informational exchange. They share information and make commercial and business transactions. All this activity is possible because tens of thousands of networks are connected to the Internet and exchange information in the same basic ways.
TheWorld Wide Web (WWW) is a part of the Internet. But it’s not a collection of networks. Rather, it is information that is connected or linked together like a web. You access this information through one interface or tool called a Web browser. The number of resources and services that are part of the World Wide Web is growing extremely fast. In 1996 there were more than 20 million users of the WWW, and more than half the information that is transferred across the Internet is accessed through the WWW. By using a computer terminal (hardware) connected to a network that is a part of the Internet, and by using a program (software) to browse or retrieve information that is a part of the World Wide Web, the people connected to the Internet and World Wide Web through the local providers have access to a variety of information. Each browser provides a graphical interface. You move from place to place, from site to site on the Web by using a mouse to click on a portion of text, icon or region of a map. These items are called hyperlinks or links. Each link you select represents a document, an image, a video clip or an audio file somewhere on the Internet. The user doesn’t need to know where it is, the browser follows the link.
All sorts of things are available on the WWW. One can use Internet for recreational purposes. Many TV and radio stations broadcast live on the WWW. Essentially, if something can be put into digital format and stored in a computer, then it’s available on the WWW. You can even visit museums, gardens, cities throughout the world, learn foreign languages and meet new friends. And, of course, you can play computer games through WWW, competing with partners from other countries and continents.
Just a little bit of exploring the World Wide Web will show you what a lot of use and fun it is.
Vocabulary:
World Wide Web — «Всемирная Паутина»
to retrieve — извлекать
variety — разнообразие, спектр
recreation — развлечение
network — сеть
to share — делить
humanities — гуманитарные науки
business transactions — коммерческие операции
access — доступ
to browse — рассматривать, разглядывать
browser— браузер (программа поиска информации)
to provide — обеспечивать (чем-либо)
provider — провайдер (компания, предоставляющая доступ к WWW через местные телефонные сети)
broadcast live — передавать в прямом эфире site — страница, сайт
to link — соединять
hyperlink — гиперссылка
to compete — соревноваться
General understanding:
1) What is Internet used for?
2) Why so many activities such as e-mail and business transactions are possible through the Internet?
3) What is World Wide Web?
4) What is Web browser?
5) What does a user need to have an access to the WWW?
6) What are hyperlinks?
7) What resources are available on the WWW?
8) What are the basic recreational applications of WWW?
Exercise 9.8. Which of the listed below statements are true/false. Specify your answer using the text.
1) There are still not so many users of the Internet.
2) There is information on all sorts of topics on the Internet, including education and weather forecasts.
3) People can communicate through e-mail and chat programs only.
4) Internet is tens of thousands of networks which exchange the information in the same basic way.
5) You can access information available on the World Wide Web through the Web browser.
6) You need a computer (hardware) and a special program (software) to be a WWW user.
7) You move from site to site by clicking on a portion of text only.
8) Every time the user wants to move somewhere on the ‘eh he/she needs to step by step enter links and addresses.
9) Films and pictures are not available on the Internet.
10) Radio and TV-broadcasting is a future of Internet. They’re not available yet.
Exercise 9.9. Define the following using the vocabulary:
2) World Wide Web
4) Internet provider
Exercise 9.10. Find the equivalents:
1) Объем ресурсов и услуг, которые являются частью WWW, растет чрезвычайно быстро.
2) Каждая ссылка, выбранная вами представляет документ, графическое изображение, видеоклип или аудио файл где-то в Интернет.
3) Интернет может быть также использован для целей развлечения.
4) Вы получаете доступ к ресурсам Интернет через интерфейс или инструмент, который называется веб-браузер.
5) Вся эта деятельность возможна благодаря десяткам тысяч компьютерных сетей, подключенных к Интернет и обменивающихся информацией в одном режиме.
6) Пользователи общаются через электронную почту, дискуссионные группы, чэт-каналы (многоканальный разговор в реальном времени) и другие средства информационного обмена.
Exercise 9.11. Match the following:
1) You access the information through one interface or tool called a.
2) People connected to the WWW through the local. have access to a variety of information.
3) The user doesn’t need to know where the site is, the. follows the.
4) In 1996 there were more than 20 million users of the.
5) Each. provides a graphical interface.
6) Local. charge money for their services to access. resources.
Words to match with:
1) web browser, providers, link, WWW,
Questions for group discussion:
2) World famous authors and publishers say that the Internet violates their copyright because Web-programmers put all kinds of books, pictures, music, films and programs free on the Internet and this reduces their sales and profits.
3) Has anyone in your group experience working on the Internet? Ask them 1) about the difficulties they had; 2) useful information retrieved; 3) fun they got? Why so few people have experience working on the Internet?
Срочно. ответь на вопросы после текста! INTRODUCTION TO THE WWW AND THE INTERNET Millions of …
Срочно. ответь на вопросы после текста!
INTRODUCTION TO THE WWW AND THE INTERNET
Millions of people around the world use the Internet to search for and retrieve information on all sorts of topics in a wide variety of areas including the arts, business, government, humanities, news, politics and recreation. People communicate through electronic mail (e-mail), discussion groups, chat channels and other means of informational exchange. They share information and make commercial and business transactions. All this activity is possible because tens of thousands of networks are connected to the Internet and exchange information in the same basic ways.
The World Wide Web (WWW) is a part of the Internet. But it’s not a collection of networks. Rather, it is information that is connected or linked together like a web. You access this information through one interface or tool called a Web browser. The number of resources and services that are part of the World Wide Web is growing extremely fast. In 1996 there were more than 20 million users of the WWW, and more than half the information that is transferred across the Internet is accessed through the WWW. By using a computer terminal (hardware) connected to a network that is a part of the Internet, and by using a program (software) to browse or retrieve information that is a part of the World Wide Web, the people connected to the Internet and World Wide Web
through the local providers have access to a variety of information. Each browser provides a graphical interface. You move from place to place, from site to site on the Web by using a mouse to click on a portion of text, icon or region of a map. These items are called Hyperlinks or links. Each link you select represents a document, an image, a video clip or an audio file somewhere on the Internet. The user doesn’t need to know where it is, the browser follows the link.
All sorts of things are available on the WWW. One can use Internet for recreational purposes. Many TV and radio stations broadcast live on the WWW. Essentially, if something can be put into digital format and stored in a computer, then it’s available on the WWW. You can even visit museums, gardens, cities throughout the world, learn foreign languages and meet new friends. And of course you can play computer games through WWW, competing with partners from other countries and continents.
Just a little bit of exploring the World Wide Web will show you what a much of use and fun it is.
Вот вопросы:
Answer the questions:
1) What is Internet used for?
2) Why so many activities such as e-mail and business transactions are possible through the Internet?
3) What is World Wide Web?
4) What is a Web browser? 5) What does user need to have an access to the WWW?
6) What are hyperlinks?
7) What resources are available on the WWW?
8) What are the basic recreational applications of WWW?
Даю 35 баллов.
What is Internet? Definition, Uses, Working, Advantages and Disadvantages
Internet is the foremost important tool and the prominent resource that is being used by almost every person across the globe. It connects millions of computers, webpages, websites, and servers. Using the internet we can send emails, photos, videos, messages to our loved ones. Or in other words, the internet is a widespread interconnected network of computers and electronics devices(that support internet). It creates a communication medium to share and get information online. If your device is connected to the Internet then only you will be able to access all the applications, websites, social media apps, and many more services. Internet nowadays is considered as the fastest medium for sending and receiving information.
Origin Of Internet: The internet came in the year 1960 with the creation of the first working model called ARPANET (Advanced Research Projects Agency). It allowed multiple computers to work on a single network that was their biggest achievement at that time. ARPANET use packet switching to communicate multiple computer systems under a single network. In October 1969, using ARPANET first message was transferred from one computer to another. After that technology continues to grow.
How is the Internet set up?
The internet is set up with the help of physical optical fiber data transmission cables or copper wires and various other networking mediums like LAN, WAN, MAN, etc. For accessing the Internet even the 2g, 3g, and 4g services and the wifi require these physical cable setup to access the Internet. There is an authority named ICANN (Internet Corporation for Assigned Names and Numbers) located in the USA which manages the Internet and protocols related to it like IP addresses.
How does the internet works?
The actual working of the internet takes place with the help of clients and servers. Here the client is a laptop that is directly connected to the internet and servers are the computers connected indirectly to the Internet and they are having all the websites stored in those large computers. These servers are connected to the internet with the help of ISP (Internet Service Providers) and will be identified with the IP address. Each website has its Domain name as it is difficult for any person to always remember the long numbers or strings. So, whenever you search any domain name in the search bar of the browser the request will be sent to the server and that server will try to find the IP address from the Domain name because it cannot understand the domain name. After getting the IP address the server will try to search the IP address of the Domain name in a Huge phone directory that in networking is known as a DNS server (Domain Name Server). For example, if we have the name of a person and you can easily find the Aadhaar number of him/her from the long directory as simple as that.
So after getting the IP address the browser will pass on the further request to the respective server and now the server will process the request to display the content of the website which the client wants. If you are using a wireless medium of Internet like 3g and 4g or other mobile data then the data will start flowing from the optical cables and will first reach to towers from there the signals will reach your cell phones and Pc’s through electromagnetic waves. And if you are using routers then optical fiber connecting to your router will help in connecting those light-induced signals into electrical signals and with the help of ethernet cables internet reaches your computers and hence the required information.
What is an IP address?
IP address stands for internet protocol address. Every PC/Local machine is having an IP address and that IP address is provided by the Internet Service Providers (ISP’s). These are some sets of rules which govern the flow of data whenever a device is connected to the Internet. It differentiates computers, websites, and routers. Just like human identification cards like Aadhaar cards, Pan cards, or any other unique identification documents. Every laptop and desktop has its own unique IP address for identification. It’s an important part of internet technology. An IP address is displayed as a set of four-digit like 192.154.3.29. Here each number on the set ranges from 0 to 255. Hence, the total IP address range from 0.0.0.0 to 255.255.255.255.
World Wide Web(WWW)
The worldwide web is a collection of all the web pages, web documents that you can see on the Internet by searching their URLs (Uniform Resource Locator) on the Internet. For example, www.geeksforgeeks.org is a URL of the GFG website and all the content of this site like webpages and all the web documents are stored on the worldwide web. Or in other words, the world wide web is an information retrieval service of the web. It provides users a huge array of documents that are connected to each other by means of hypertext or hypermedia links. Here, hyperlinks are known as electronic connections that link the related data so that users can easily access the related information and hypertext allows the user to pick a word or phrase from text, and using this keyword or word or phrase can access other documents that contain additional information related to that word or keyword or phrase. World wide web is a project which is created by Timothy Berner’s Lee in 1989, for researchers to work together effectively at CERN. It is an organization, named World Wide Web Consortium (W3C), which was developed for further development in the web.
Difference between Worldwide Web and Internet
The difference between the world wide web and the internet are:
Uses of the Internet
Some of the important usages of the internet are:
Text C: «INTRODUCTION TO THE WWW AND THE INTERNET»
Millions of people around the world use the Internet to search for and retrieve information on all sorts of topics in a wide variety of areas including the arts, business, government, humanities, news, politics and recreation. People communicate through electronic mail (e-mail), discussion groups, chat channels and other means of informational exchange. They share information and make commercial and business transactions. All this activity is possible because tens of thousands of networks are connected to the Internet and exchange information in the same basic ways.
The World Wide Web (WWW) is a part of the Internet. But it’s not a collection of networks. Rather, it is information that is connected or linked together like a web. You access this information through one interface or tool called a Web browser. The number of resources and services that are part of the World Wide Web is growing extremely fast. In 1996 there were more than 20 million users of the WWW, and more than half the information that is transferred across the Internet is accessed through the WWW. By using a computer terminal (hardware) connected to a network that is a part of the Internet, and by using a program (software) to browse or retrieve information that is a part of the World Wide Web, the people connected to the Internet and World Wide Web through the local providers have access to a variety of information. Each browser provides a graphical interface. You move from place to place, from site to site on the Web by using a mouse to click on a portion of text, icon or region of a map. These items are called hyperlinks or links. Each link you select represents a document, an image, a video clip or an audio file somewhere on the Internet. The user doesn’t need to know where it is, the browser follows the link.
All sorts of things are available on the WWW. One can use Internet for recreational purposes. Many TV and radio stations broadcast live on the WWW. Essentially, if something can be put into digital format and stored in a computer, then it’s available on the WWW. You can even visit museums, gardens, cities throughout the world, learn foreign languages and meet new friends. And, of course, you can play computer games through WWW, competing with partners from other countries and continents.
Just a little bit of exploring the World Wide Web will show you what a lot of use and fun it is.
World Wide Web — «Всемирная Паутина»
to retrieve — извлекать
variety — разнообразие, спектр
to share — делить
humanities — гуманитарные науки
business transactions — коммерческие операции
to browse — рассматривать, разглядывать
browser — браузер (программа поиска информации)
to provide — обеспечивать (чем-либо)
provider — провайдер (компания, предоставляющая доступ к WWW через местные телефонные сети)
broadcast live — передавать в прямом эфире site — страница, сайт
to link — соединять
to compete — соревноваться
1) What is Internet used for?
2) Why so many activities such as e-mail and business transactions are possible through the Internet?
3) What is World Wide Web?
4) What is Web browser?
5) What does a user need to have an access to the WWW?
6) What are hyperlinks?
7) What resources are available on the WWW?
8) What are the basic recreational applications of WWW?
Exercise 9.8. Which of the listed below statements are true/false. Specify your answer using the text.
1) There are still not so many users of the Internet.
2) There is information on all sorts of topics on the Internet, including education and weather forecasts.
3) People can communicate through e-mail and chat programs only.
4) Internet is tens of thousands of networks which exchange the information in the same basic way.
5) You can access information available on the World Wide Web through the Web browser.
6) You need a computer (hardware) and a special program (software) to be a WWW user.
7) You move from site to site by clicking on a portion of text only.
8) Every time the user wants to move somewhere on the ‘eh he/she needs to step by step enter links and addresses.
9) Films and pictures are not available on the Internet.
10) Radio and TV-broadcasting is a future of Internet. They’re not available yet.
Exercise 9.9. Define the following using the vocabulary:
2) World Wide Web
4) Internet provider
Exercise 9.10. Find the equivalents:
1) Объем ресурсов и услуг, которые являются частью WWW, растет чрезвычайно быстро.
2) Каждая ссылка, выбранная вами представляет документ, графическое изображение, видеоклип или аудио файл где-то в Интернет.
3) Интернет может быть также использован для целей развлечения.
4) Вы получаете доступ к ресурсам Интернет через интерфейс или инструмент, который называется веб-браузер.
5) Вся эта деятельность возможна благодаря десяткам тысяч компьютерных сетей, подключенных к Интернет и обменивающихся информацией в одном режиме.
6) Пользователи общаются через электронную почту, дискуссионные группы, чэт-каналы (многоканальный разговор в реальном времени) и другие средства информационного обмена.
Exercise 9.11. Match the following:
1) You access the information through one interface or tool called a.
2) People connected to the WWW through the local. have access to a variety of information.
3) The user doesn’t need to know where the site is, the. follows the.
4) In 1996 there were more than 20 million users of the.
5) Each. provides a graphical interface.
6) Local. charge money for their services to access. resources.
Words to match with:
1) web browser, providers, link, WWW,
Questions for group discussion:
2) World famous authors and publishers say that the Internet violates their copyright because Web-programmers put all kinds of books, pictures, music, films and programs free on the Internet and this reduces their sales and profits.
3) Has anyone in your group experience working on the Internet? Ask them 1) about the difficulties they had; 2) useful information retrieved; 3) fun they got? Why so few people have experience working on the Internet?
FAMOUS PEOPLE OF SCIENCE AND ENGINEERING
William Henry Gates was born in Seattle, Washington, in 1955.
He is an American business executive, chairman and chief executive officer of the Microsoft Corporation. Gates was the founder of Microsoft in 1975 together with Paul Alien, his partner in computer language development. While attending Harvard in 1975, Gates together with Alien developed a version of the BASIC computer programming language for the first personal computer.
In the early 1980s. Gates led Microsoft’s evolution from the developer of computer programming languages to a large computer software company. This transition began with the introduction of MS-DOS, the operating system for the new IBM Personal Computer in 1981. Gates also led Microsoft towards the introduction of application software such as the Microsoft Word processor.
Much of Gates’ success is based on his ability to translate technical visions into market strategy. Although Gates has accumulated great wealth from his holdings of Microsoft stock, he has been known as a tough competitor who seems to value winning in a competitive environment over money. Gates still continues to work personally in product development at Microsoft.
ALLOYS
Bronze and brass, the first alloys in the history of metallurgy, were probably obtained by man accidentally when melting mixed metal ores. Much later alloys of iron were obtained.
Steel was made in small quantities in early times until the mid-19th century when it was manufactured on a large scale in the iron and steel industry.
The commercial production of pure aluminium in about 1890 began a new range of alloys and among them duralumin, an alloy of about 94 per cent aluminium, with small quantities of copper, manganese, magnesium, and silicon. Most of aluminium alloys are both light and strong.
Nickel is often mixed with other metals for special purposes: permalloy is a nickel-iron alloy that is magnetically soft. The polarity of its magnetic field can be easily changed and it is used for transformer cores. Monel metals contain about two parts nickel to one part copper, plus other elements. They are stronger than nickel and extremely corrosion-resistant. These properties make them useful in chemical production.
Electrum is a natural or artificial alloy of gold and silver containing 15-45 per cent of silver. It was used in the ancient world for coinage.
Bismuth is frequently used as a part of alloys with low melting-points. Today alloys can be designed for particular applications with certain properties.
2. MANUFACTURING OF PLASTICS
The manufacture of plastic and plastic products involves procuring the raw materials, synthesizing the basic polymer, compounding the polymer into a material useful for fabrication, and moulding or shaping the plastic into its final form.
Originally, most plastics were made from resins derived from vegetable matter, such as cellulose (from cotton), oils (from seeds), starch derivatives, or coal. Casein (from milk) was among the nonvegetable materials used. Although the production of nylon was originally based on coal, air, and water, and nylon 11 is still based on oil from castor beans, most plastics today are derived from petrochemicals. These oil-based raw materials are relatively widely available and inexpensive. However, because the world supply of oil is limited, other sources of raw materials, such as coal gasification, are being explored.
Synthesizing the Polymer
The first stage in manufacturing plastic is polymerization. As noted, the two basic polymerization methods are condensation and addition reactions. These methods may be carried out in various ways. In bulk polymerization, the pure monomer alone is polymerized, generally either in the gaseous or liquid phase, although a few solid-state polymerizations are also used. In solution polymerization, an emulsion is formed and then coagulated. In interfacial polymerization, the monomers are dissolved in two immiscible liquids, and the polymerization occurs at the interface of the two liquids.
Chemical additives are often used in plastics to produce some desired characteristic. For instance, antioxidants protect a polymer from chemical degradation by oxygen or ozone; similarly, ultraviolet stabilizers protect against weathering. Plasticizers make a polymer more flexible, lubricants reduce problems with friction, and pigments add colour. Among other additives are flame retardants and antistatics.
Many plastics are manufactured as composites. This involves a system where reinforcing material (usually fibres made of glass or carbon) is added to a plastic resin matrix. Composites have strength and stability comparable to that of metals but generally with less weight. Plastic foams, which are composites of plastic and gas, offer bulk with low weight.
Shaping and Finishing
The techniques used for shaping and finishing plastics depend on three factors: time, temperature, and flow (also known as deformation). Many of the processes are cyclic in nature, although some fall into the categories of continuous or semicontinuous operation.
One of the most widely used operations is that of extrusion. An extruder is a device that pumps a plastic through a desired die or shape. Extrusion products, such as pipes, have a regularly shaped cross section. The extruder itself also serves as the means to carry out other operations, such as blow moulding and injection moulding. In extrusion blow moulding, the extruder fills the mould with a tube, which is then cut off and clamped to form a hollow shape called a parison. The hot, molten parison is then blown like a balloon and forced against the walls of the mould to form the desired shape. In injection moulding, one or more extruders are used with reciprocating screws that move forwards to inject the melt and then retract to take on new molten material to continue the process. In injection blow moulding, which is used in making bottles for carbonated drinks, the parison is first injection moulded and then reheated and blown.
In compression moulding, pressure forces the plastic into a given shape. Another process, transfer moulding, is a hybrid of injection and compression moulding: the molten plastic is forced by a ram into a mould. Other finishing processes include calendering, in which plastic sheets are formed, and sheet forming, in which the plastic sheets are formed into a desired shape. Some plastics, particularly those with very high temperature resistance, require special fabrication procedures. For example, polytetrafluoroethene (Teflon) has such a high melt viscosity that it is first pressed into shape and then sintered—exposed to extremely high temperatures that bond it into a cohesive mass without melting it. Some polyamides are produced by a similar process.
Plastics have an ever-widening range of uses in both the industrial and consumer sectors.
The packaging industry is a leading user of plastics. Much LDPE (low-density polyethene) is marketed in rolls of clear-plastic wrap. High-density polyethene (HPDE) is used for some thicker plastic films, such as those used for plastic waste bags and containers. Other packaging plastics include polypropene, polystyrene, polyvinyl chloride (PVC), and polyvinylidene chloride. Polyvinylidene chloride is used primarily for its barrier properties, which can keep gases such as oxygen from passing into or out of a package. Similarly, polypropene is an effective barrier against water vapour. Polypropene is also often used in housewares and as a fibre for carpeting and rope.
The building industry is a major consumer of plastics, including many of the packaging plastics mentioned above. HDPE is used for pipes, as is PVC. PVC is also used in sheets for building materials and similar items. Many plastics are used to insulate cables and wires, and polystyrene in the form of foam serves as insulation for walls, roofs, and other areas. Other plastic products are roofing, door and window frames, mouldings, and hardware.
Many other industries, especially motor manufacturing, also depend on plastics. Tough engineering plastics are found in vehicle components like fuel lines, fuel pumps, and electronic devices. Plastics are also used for interior panelling, seats, and trim. Many car bodies are made of fibreglass-reinforced plastic.
Among the other uses of plastic are housings for business machines, electronic devices, small appliances, and tools. Consumer goods range from sports equipment to luggage and toys
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Источники информации:
- http://studopedia.ru/4_33803_Text-C-INTRODUCTION-TO-THE-WWW-AND-THE-INTERNET.html
- http://matfaq.ru/question/srochnootvet-na-voprosy-posle-teksta-introduction-to-the-www-and-the-internet-millions-of/
- http://www.geeksforgeeks.org/what-is-internet-definition-uses-working-advantages-and-disadvantages/
- http://lektsiopedia.org/lek-41365.html