Posts Tagged ‘second world war’
September 11th, 2009 | 
Author: Since their invention in the late 1800s vacuum cleaners have become an essential household appliance worldwide. While the basic early models were bulky and heavy, they were an immediate hit and have evolved into the hi-tech, many-featured models that we know these days.
The original electric vacuum cleaner, produced by Nilfisk, emerged early in the last century. But vacuum cleaners didn’t truly become popular as a consumer appliance until after the Second World War when they became popular among the middle classes. The growth in demand and sales prompted ever more hi-tech and lightweight vacuum cleaners, and a drop in prices.
These days there are two basic models of vacuum cleaner available on the market – upright and canister – and each offers its own good points and bad points.
Upright cleaners – These have a cleaning device on the floor with a handle and bag for the dust attached. They normally have wheels and are rolled in front of the user. Upright vacuum cleaners are most suitable for larger, open spaces and are a popular choice because the user can remain in standing position while operating.
However, these vacuum cleaners do have their drawbacks. The main drawback is that they do not operate efficiently in cramped areas. They are difficult to move under and around furniture, although many models now come with hoses which helps address the issue. Upright vacuum cleaners sometimes do not have retractable power chords, they are heavy and unwieldy, and are difficult to use on stairways.
Canister vacuum cleaners – Canister vacuum cleaners are comprised of a cleaning unit and bag which are held in a ‘canister’, with a long, flexible pipe that is connected to the vacuum head. Canister vacuum cleaners are a popular pick with consumers as they are more lightweight and the design makes it much simpler to vacuum on staircases, in small spaces and in corners. Canister vacuum cleaners also come with a range of head fittings so they are extremely versatile. For example, there are particular fittings for cleaning your vehicle or your drapes.
However, canister vacuum cleaners have their drawbacks too. They can be difficult to use in their own fashion as you need to drag the canister behind you. Also, the dirt bags are often smaller so will require more frequent changing.
Though upright and canister vacuums have changed little in basic design over the past number of years, some innovative extra features have been added to both designs. These include wet/dry or pneumatic vacuum cleaners which can be used to clean up wet spills, as well as normal dust.
Another example was the Dyson vacuum cleaner, which ended the requirement for bags, instead channeling the dust into a plastic container that can be detached and emptied.
Jim Samposzi is a freelance writer with over fifteen years of editorial experience. Jim is employed as a technical writer for our b2b site and has become the resident guru on vacuum cleaners. Visit our very useful web portal for additional information on Vacuum Cleaner and Robot Vacuum.
Article Source: How To Choose Your Next Vacuum Cleaner
The phenomenon of electromagnetic induction was first discovered by Michael Faraday in 1831, and it is evident that he realised at least a part of its future potential in the modern world. A contemporary politician asked him about the usefulness of the discovery; he answered ‘at present I do not know, but one day you will be able to put a tax on it.’
The earliest record of using electromagnetic technology to locate buried cables dates from around 1910. More portable locators were made over the next years and the Sharman Main Finder was just one example. The user instructions give a tinge of envy to anyone trying to trace gas pipes .. ..’just clip the generator to a gas bracket in the nearest house or onto a street lamp.’
American and German schools of design emerged during the years leading up to the Second World War. In North America roads were wide and wide cables hung on poles so the main requirement for a locator was to locate widely spaced buried pipes. The result was a simple, high frequency, low power and low cost locator.
In Germany, cables as well as pipes were buried under narrow streets, so elaborate low frequency and high power locators were developed that required considerable expertise to obtain satisfactory results.
Dr Gerhard Fisher of California designed the Metallascope, the first high performance buried pipe and cable locating set. His system made use of the latest scientific developments and his company exists today and still produces the M-scope, an up-to-date descendent of the original Metallascope.
One of the engineering sections of Bell Laboratories studied the problem of accurate location of newly buried cables and recognised that an antenna with twin sensing aerials would give more positive plan definition, and also measure the depth of a target cable. The subsequent design, called the Depthometer, was engineered and manufactured in 1964. It was another 12 years before the first commercial twin aerial antenna locator was made by the Electrolocation company in Bristol England.
The twin aerial system was found to have substantial advantages over single aerial locators. Twin sensing aerials combined the seemingly contradictory qualities of discrimination with sensitivity. For the first time it was possible to locate buried cables below an overhead power line and to sort out crowded utility services under a city street intersection.
The introduction of the twin aerial antenna coupled with miniaturised electronic circuitry coincided with a programme of extending and upgrading utility distribution systems. This growing demand and technical progress resulted in a series of advances and new features to make locating more certain and more simple. Some of these advances included:
” Combination of active and passive signal reception
” Multi-frequency locating sets enabling the user to select the most suitable frequency for each application
” Electronic depth measurement.
” Current measurement along the length of a pipe or cable to detect coating or insulation defects.
” Current direction recognition to verify the identity of a target line.
” Permanently installed signal transmitters to apply a signal tone to a telephone cable over distances up to 150km/100 miles.
Today, electromagnetic locators are the worldwide standard for locating buried pipes and cables. A number of specialised manufacturers offer a choice of locators ranging from simple equipment used to detect the presence of buried cables to sophisticated instruments for pinpointing, identifying and fault finding buried pipes and cables in the most complex situations.
Written by Select Surveys, one of the UK’s leading independent surveying companies specialising in using electromagnetic, CAT and ground penetrating radar equipment to detect underground cables and utilities.
Article Source: A History of Underground Electromagnetic Surveying
In June this year, researchers at the University of Leeds developed a technology set to revolutionize the washing machine industry. By using plastic granules and just a cup of water per cycle, the design is a milestone of the washing machine industry and might well be the first commercially used near-waterless washing machine on the market, as soon as 2009. The front-loading design of what we know and love in Europe as The Washing Machine has seemingly come a long way over the years. So this is its history – in less than 500 words.
In the 1950s, as the UK and Europe recover from the Second World War, electric washing machines start to become popular. With the introduction of the Rolls Razor machine during the 60s, cheap washing machines boom began with the company selling in the region of 200,000 by the end of 1963. Due to the Postal Strike of 1964 and other factors such as a so-called war between retailers and sales, the company went into liquidation, finally falling to the hands of Ariston in the late 70s.
The front loading automatic washing machine boomed in popularity during the 70s. At this time a design change occurred with the electronic (as opposed to mechanical) control of drum speed during washes. The next big design change came in the 90s and was introduced by James Dyson, famed for his reinvention of the vacuum cleaner. His redesign incorporated two drums that revolved in opposition with the aim of cutting wash time and providing cleaner clothes in the end. The product never took off commercially however and is now out of production.
In 2006, Japanese company Sanyo introduced the AWD-AQ1, a front-loading washer that utilized two new technologies called ‘Air Wash’ and ‘Aqualoop’. The former process involves an air jet pumped in the drum instead of water to break down odour, whilst the latter means that the minimal water that is stored in the machine is recycled by being infused with bubbles at the end of each cycle. Sanyo have also released a model with a door that opens from the left – another important milestone in washing machine design.
In recent years EU directives have heralded the introduction of energy labels for white goods that rate the product’s efficiency as well as giving other valuable information as standard – such as performance and energy consumption. The models are rated from A to G with A being more energy efficient and G being less energy efficient.
It’s with this cultural shift toward desirable greener products that has shaped the most recent design of the humble washing machine. The new technology devised by the University of Leeds, called Xeros, achieves an astonishing level of cleaning whilst using 2% of the amount of water of a typical machine, and is set to revolutionize the industry.
For a range of goods from computers to garden products, furniture, cheap washing machines through ink cartridges to clothing and even a four poster bed, uk.shopping.com and dealtime.co.uk are a great way to find products online, and include product reviews.
Article Source: The History of The Front-Loading Washing Machine – in Less Than 500 words