Why do washing machines need so many programs?

Your machine doesn't know what you put into it and can't automatically tell how carefully to wash something like a delicate woollen jumper—because it doesn't know that's what it's got to do! The only things under its control are the amount and temperature of the water, the speed of the spin, the number of times the drum oscillates, the number of rinses, and so on. No-one wants to wash clothes in a scientific way: " I think I need 5.42 litres of water at exactly 42°C, I'll need to wash for exactly 34 minutes, and I'll need 200 spin revolutions when I'm done." That would give us literally an infinite number of possibilities, which is too muсh. Recognizing this, machine engineers try to make life easy by offering a few preset programs: each one uses a slightly different combination of these variables so it washes safely within the tolerance of different fabrics.

 

Why does that matter? All fabrics are different. A fabric like wool is immensely strong but has two big drawbacks (from the point of getting it clean): it's extremely hygroscopic (absorbs huge amounts of water) and loses its elasticity as the temperature increases. So if you're designing a washing machine to wash woollens, that's your starting point: don't allow the wool to become too hot (because the fibers will degrade and stretch too much) and don't agitate it excessively because it will stretch and not return to shape. With sturdier fabrics like denim, you can afford to bash them about in the drum much more—indeed, you must do so, because you need the agitation to get the detergent deep into the fibers and break up the dirt (and, of course, clothes made from denim are more likely to get dirtier than more delicate fabrics such as cashmere jumpers, which people treat more carefully).

 

Each program you find marked on a clothes washing machine is a best guess by the engineers as to how much agitation a particular garment/fabric is likely to need and how much it can put up with without getting damaged. If you were handwashing in a sink, you'd make those judgements instinctively, balancing the need to get your garment clean with the need to protect it from damage. While your brain/hands would do that without thinking, the washing machine does it with a certain wash temperature, so many agitations, so many spins, and a certain spin speed.

 

Vocabulary

trickle - течь

trap -удерживать, улавливать; поглощать

mph - miles per hour

flung – past oт fling – метать, бросать,

marvel – изумляться

oscillate – [‘osileit] – качаться, колебаться,

i’mmensely – чрезвычайно

hygroscopic [, haigrə ’skopik]- гигроскопичный

sturdy – прочный, крепкий,

agitate – трясти, взбалтывать

Exercise 1

Find Russian equivalents to the following words in the text. Learn them by heart.

Включать, выключать, лоток/желоб, наполнять, измерять, поступающий, стекать, избавиться, опустошить, крохотный, вращение, центрифуга, отличать, ткань, бесконечный, вероятность, недостаток, огромный, чрезмерно, ослабевать, растягивать, прочный, выдерживать/терпеть

Exercise 2

Which words from Exercise 1 are coded here?

arty, bawradck, tcherst, ominngic, nardi, ingsnipn, nyit, barfic, sumerae, durtys

 

Exercise 3

Match the beginnings of the word combinations to their endings

1) switch 2) get rid 3) fill 4) switch 5) put up

a) of b) with c) off d) on e) up

 

Exercise 4

Match two parts of the sentences

1) Please switch the lights off 2) The electricity has been switched off, 3) We got rid of 4) He brought her breakfast in bed 5) A ship's speed is measured 6) He filled up 7) This is the one major drawback 8) I'm not going to put up 9) Soft, springy materials like rubber and skin don't tear easily 10) The president was 11) He gazed up at her

a) the tank with oil. b) all the old furniture. c) with huge brown eyes. d) so I can’t watch TV now. e) in knots. f) with their smoking any longer. g) on a tray. h) as you leave. i) immensely popular j) because they stretch before breaking apart. k) of the new system.

 

Exercise 5

Make the underlined sentences negative and interrogative. Use grammar references.

 

 

Lesson 7

What is 3D printing?

Part 1

3D printing or additive manufacturing is a process of making three dimensional solid objects from a digital file. The creation of a 3D printed object is achieved using additive processes. In an additive process an object is created by laying down successive layers of material until the entire object is created. Each of these layers can be seen as a thinly sliced horizontal cross-section of the eventual object.

 

How does 3D printing work?

It all starts with making a virtual design of the object you want to create. This virtual design is made in a CAD (Computer Aided Design) file using a3D modeling program (for the creation of a totally new object) or with the use of a 3D scanner (to copy an existing object). A 3D scanner makes a 3D digital copy of an object.

 

3d scanners use different technologies to generate a 3d model such as time-of-flight, structured / modulated light, volumetric scanning and many more.

 

Recently, many IT companies like Microsoft and Google enabled their hardware to perform 3d scanning, a great example is Microsoft’s Kinect. This is a clear sign that future hand-held devices like smartphones will have integrated 3d scanners. Digitizing real objects into 3d models will become as easy as taking a picture. Prices of 3d scanners range from very expensive professional industrial devices to 30 USD DIY devices anyone can make at home.

 

To prepare a digital file for printing, the 3D modeling software “slices” the final model into hundreds or thousands of horizontal layers. When the sliced file is uploaded in a 3D printer, the object can be created layer by layer. The 3D printer reads every slice (or 2D image) and creates the object, blending each layer with hardly any visible sign of the layers, with as a result the three dimensional object.

 

Processes and technologies

Not all 3D printers use the same technology. There are several ways to print and all those available are additive, differing mainly in the way layers are build to create the final object.
Some methods use melting or softening material to produce the layers. Selective laser sintering (SLS) and fused deposition modeling (FDM) are the most common technologies using this way of printing. Another method of printing is when we talk about curing a photo-reactive resin with a UV laser or another similar power source one layer at a time. The most common technology using this method is called stereolithography (SLA).

 

To be more precise: since 2010, the American Society for Testing and Materials (ASTM) group “ASTM F42 – Additive Manufacturing”, developed a set of standards that classify the Additive Manufacturing processes into 7 categories according to Standard Terminology for Additive Manufacturing Technologies. These seven processes are:

1. Vat Photopolymerisation

2. Material Jetting

3. Binder Jetting

4. Material Extrusion

5. Powder Bed Fusion

6. Sheet Lamination

7. Directed Energy Deposition

 

Vocabulary

‘additive manufacturing - технология послойной печати

cross-section - поперечное сечение

eventual – конечный, возможный при соответствующих условиях

computer aided design - компьютерное моделирование

time-of-flight - времяпролётный

modulated light - модулированное световое излучение, модулированный световой сигнал

volumetric - волюметрический (напр. о модели); пространственный

enable - приспосабливать; давать возможность

hand-held – ручной, переносной

‘digitizing - отцифрование

DIY - do it yourself - сделай сам

Selective laser sintering - избирательное лазерное спекание

fused deposition modeling - моделирование методом наплавления

reactive resin - реактивная смола

UV - Ultra Violet - ультрафиолетовый

stereolithography - стереолитография

VAT – куб, кубовый, контейнер

jetting - гидромеханизация; гидромониторное бурение;

binder jetting - Разбрызгивание связующего вещества

extrusion - горячее прессование

powder bed fusion - технология расплавления материала в заранее сформированном слое

lamination - напластование

directed energy deposition - осаждение материала при помощи направленного энергетического воздействия

 

Exercise 1

⇐ Предыдущая1234567Следующая ⇒

Поделиться:

Популярное:

1. Achievement- достижение, успех, победа
2. Aufgabe 32. Lesen Sie und inszenieren Sie den folgenden Dialog.
3. Booking-clerk: Return or single ticket?
4. Checking and Valuing Features
5. ECOLOGY: ORGANISMS AND THEIR INTERACTION
6. Endow (наделять, одарять, обеспечивать доходом)
7. English Literature in the Beginning of the 19th Century
8. Ex. 108, p. 493 (possible variants)
9. Ex.1. Дополните предложения, используя условные конструкции и информацию из текста.
10. Ex.2. Раскройте скобки, употребляя глаголы в корректной форме.
11. EXERCISE 8 Answer questions about the text.
12. EXERCISE 9 Translate the sentences from Russian into English.