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Think Outside the Sewer

Wed, 03/07/2018 - 13:45

On the outskirts of Bangalore, India’s tech capital, an office doubles as a museum of the toilet. An exhibit in one room traces the history of sanitation, from ancient Mesopotamian sewers to Europe’s first flush toilets and the modern sewer systems built to process the waste they spurt out. Then, another exhibit turns to the global sanitation crisis — including a sculpture of naked babies representing the half-million children under 5 who die from diarrhea annually — and technologies to tackle it.

CDD Society, the nonprofit housing the display, wants Indians to think outside the sewer. It has built India’s first citywide fecal sludge treatment plant, which turns human excreta into compost with no electricity and no connection to an underground sewer…. The organization and India are only part of a growing trend across multiple developing countries, where governments, entrepreneurs and nonprofits are eschewing Western-style sewer systems that use vast piped networks to deliver waste to centralized treatment plants.

Instead, they are opting for decentralized approaches to treating poo and pee. Their models rely on trucks to transport waste to systems like septic tanks and latrine pits that use less water than sewers and recycle human waste. They are pitching themselves as the answer to the global sanitation crisis: 2.5 billion people, a third of the world’s population, lack access to a toilet, while an estimated 80 percent of human waste worldwide goes untreated.

Read more: Why Cities are Starting to Shun Sewers. Previously: Recycling animal and human dung is the key to sustainable farming.

The Internet Unplugged

Wed, 03/07/2018 - 13:44

“At first glance, it seems like the ultimate paradox: A magazine that exists only on the internet, filled with content that can only be consumed once a would-be reader has disconnected from the internet. But that’s exactly the kind of contradiction founder Chris Bolin says he was going for when he created his new magazine, The Disconnect, which launched in February.” Read more: A new digital magazine forces you to unplug from the internet.

Anti-Tech Riots

Mon, 03/05/2018 - 00:22

“If the recent speculation about jobs and AI is even close to being correct, then fairly soon “luddite” will join far-right and Islamist on the list of government-defined extremisms”. Read more: Will 2018 be the year of the neo-luddite?

Wedge Axes

Thu, 03/01/2018 - 13:57

The Finnish Leveraxe is maybe not the most revolutionary alternative to the traditional axe, writes reader Guy Verrijdt. The Logmatic Wedge Axe from New Zealand splits wood more safely and ergonomically than an axe. This video shows how it works. The tool combines elements of splitting wedges and slide hammers. There are more brands available.

Thermal Insulation of Solid-Walls is Underestimated

Tue, 02/20/2018 - 23:52

Oula Lehtinen – CC BY-SA 3.0

Approximately 5.7 million solid-walled houses exist in England, comprising 25% of the housing stock. Most were built between 1750 and 1914. Research shows that their energy efficiency has been underestimated for decades.

The English Housing Survey (EHS) defines solid-wall construction as a building where external load-bearing walls are made of brick, block, stone or flint with no cavity. In England, the shift to the use of solid-wall brick construction began during the great rebuilding from mid-16th century.

For the present English housing stock, the overwhelming fraction of solid-walled dwellings, constructed mostly of brick, derives from the expansion of population from the mid-18th century to the beginning of the First World War. Solid walls continued to be the most common construction for the domestic sector until the British housing boom of the 1920s and 1930s.

Wall Thickness

The most widely used estimate of the U-value (the measure of thermal conductivity) of a UK solid-wall property is 2.1 Wm−2 K−1. However, there is growing evidence that solid-wall U-values are much lower than previously assumed. Several studies in recent years have found that the mean or median U-values measured for solid-walled construction were around 1.3–1.4 Wm−2 K−1. There are two reasons for this large discrepancy.

First, standard solid brick wall U-values are based on an assumed wall thickness of 220 mm brick and approximately 12 mm of dense plaster. Modern bricks are 220 mm long and so this assumption would be logical for a modern brick wall. However, the thickness of 220 mm was used as a conservative estimate to capture variation in brick production. Following the Great Fire of London in 1666 brick properties over two stories were required to be constructed with walls that were more than one brick thick.

The required thickness of load-bearing masonry walls in England therefore increases with the height of the building. While two-storey buildings can be built with walls of just over 200 mm thickness, three-storey buildings require a minimum of 300 mm and four-storey buildings require walls of at least 400 mm. Consequently, it is obvious that the mean thickness of solid walls in the UK housing stock is likely to be greater than the nominal 220 mm of a single brick wall.

Air Cavities

Secondly, so-called ‘solid walls’ are in fact often not completely solid. Brick walls can be built up in a variety of different patterns, but are typically constructed with a mixture of brick types, with some going straight through the full depth of the wall, known as headers, and some laid side by side, known as stretchers. In order to allow walls to be constructed with a regular type of mortar bond, the total width of two adjacent stretchers is less than the length of a header by the width of a mortar joint, which is typically 5–10 mm.

Although some mortar will intrude into the space as snots from joints between stretchers, the practical constraints of bricklaying mean that this gap is often not filled with mortar. There is a high probability that solid-wall segments built with stretchers contain air gaps. If stretchers are assumed to comprise 50–80% of the wall surface, with air gaps of the order of ≈10 mm, then a straightforward calculation with identical assumptions regarding brick density etc. yields U-value estimates in the range of 1.65–1.8 W−1 m2 K.

‘Solid’ stone walls may also contain residual air cavities for similar reasons. Walls built with stone are often thicker overall than single-brick walls and often employ rubble-filled cores. It is almost certain that there are voids within these cores that would increase the thermal resistance of the element relative to that of a completely solid wall.

Consequences

Among the many implications for policy, discrepancy between real-world U-values and U-values assumed in energy modelling and standard UK building assessment protocols suggests that standard solid-wall U-values may be inappropriate for energy certification or for evaluating the investment economics of solid-wall insulation.

Reducing the represented U-value of solid walls in the stock from 2.1 to 1.3 Wm−2 K−1 reduces the estimated mean annual space heating demand by 16%, and causes approximately one-third of all solid-wall dwellings to change Energy Performance Certification (EPC) band.

Source:
Li, Francis GN, et al. “Solid-wall U-values: heat flux measurements compared with standard assumptions.” Building Research & Information 43.2 (2015): 238-252. http://www.tandfonline.com/doi/full/10.1080/09613218.2014.967977

Biological Pest Control: Bat Towers

Mon, 02/19/2018 - 10:14

At the turn of the twentieth century, Dr. Charles A. Campbell, a physician and former city bacteriologist in San Antonio, Texas, began the first experiments with attracting bats to artificial roosts. Although he had the highest regard for bats, the motive behind his experiments was not that he thought bats needed homes. The real reason was to find a way to control a disease that caused millions of deaths throughout the world each year: malaria. In his native Texas, mosquitoes and disease rendered countless acres of fertile land uninhabitable, and Campbell, who treated victims of malaria, knew the suffering it caused.

In the beginning Campbell thought the answer was simple: recruit great numbers of bats who, he believed, were the natural predators of mosquitoes… But after years of unsuccessful experimentation with boxes of assorted sizes and shapes, he learned that bats did not choose any old ramshackle roost at random. Undaunted, his solution was to build a bigger bat house. With a personal investment of $500.00, Campbell built the first Malaria-Eradicating, Guano-Producing Bat Roost in 1907 at the U.S. Experimental Farm near San Antonio.

He called the 30 foot tall tower “my monument.” Inside, a series of inclined shelves had been carefully crafted for the bats to roost upon, and 20 yards of guano saturated cheesecloth were festooned on the inside walls for their further comfort. The hopper, from which he intended to collect their droppings, was seeded with about 100 pounds of fresh guano. And to further attract visitors, he provided a meal: “three perfectly good hams with a nice slice cut out of each, exhibiting their splendid quality for the delection of the intended guests.”

Read more: Murphi, M. “Dr. Campbell’s malaria-eradicating, guano-produding bat roosts.” BATS Magazine7 2 (1989). See also: The Bat Tower: The 30-Foot Monument to Biological Pest Control and Cross-Species Design, The Atlantic, 2012. Via Aaron Vansintjan. Image.

Invisible Algorithms, Invisible Politics

Sun, 02/18/2018 - 22:00

We have been enticed into a world in which computing has faded into the background of everyday life, effectively becoming invisible. At the same time, we have actively concealed the ways in which these networked systems of software, data, technologies, and infrastructures “have politics”. And, with promises that computers are impartial, we have removed them from the public eye, making them difficult to expose and critique.

Yet these systems can only be understood as the flawed extensions of human creation. They act on our biases by replicating them and distributing them into the background of everyday life, thereby reinforcing and even exacerbating existing structural inequalities… Rather than letting these systems fade into the background, a deeper engagement with the material realities of digital technologies is necessary.

Read more: Invisible algorithms, invisible politics, Laura Forland. Via SF Sutcliffe.

Mobile Clothes Washer

Fri, 02/16/2018 - 22:05

The Breathing Mobile Washer was designed so that manually plunging, the washer forces water through clothing. Compared to friction washing with hands, washboards and rocks, the mobile washer is easier to use, much less abrasive, reduces wear on clothes, and provides a superior clean. Review.

 

A Good Life For All Within Planetary Boundaries

Fri, 02/16/2018 - 21:45

“No country in the world currently meets the basic needs of its citizens at a globally sustainable level of resource use. Our research, recently published in Nature Sustainability (and summarised in The Conversation) is the first to quantify the national resource use associated with achieving a good life for over 150 countries. It shows that meeting the basic needs of all people on the planet would result in humanity transgressing multiple environmental limits, based on current relationships between resource use and human well-being.”

“The purpose of this interactive website is to foster discussions about the meaning of a good life for all, and what it would mean for nations to thrive within planetary boundaries. Explore the challenge using the chart below, check out a World Map with our results, or select individual Countries to see their environmental and social performance relative to a ‘safe and just’ development space.”

More: A Good Life For All Within Planetary Boundaries, University of Leeds. Related: How Much Energy Do We Need?

Slow Travel: Crossing Europe with a Giant Land Ship

Tue, 11/28/2017 - 16:53

Belgian art collective Time Circus built their first prototype of a giant Land Ship that will travel through Europe. Like a modern-day galley, the land ship will be propelled by the muscle power of the participating travelers. The journey is understood as a 21st century pilgrimage and will take an estimated 10 years.

The Journey

Along the journey, people can board the land ship and travel along for as long as they want to. Longer stops will be made in Marseille (France), Novisad (Serbia), Timisoara (Romania) and Elefsina (Greece).

In 2018, land ship terminals will be built in these cities. Like bus stops, these will show how long it takes before the vehicle arrives. The start of the journey is planned for 2020.

The Ship

When we talked to one of the makers earlier this month in Antwerp, he said it was not yet clear whether the final vehicle would be a single monstrous land ship of 50 metres long, or a caravan of ‘smaller’ ones the size of the first prototype, which is 13 metres long.

He said they were also contemplating the use of draft animals or sails — reminiscent of the ancient Chinese wheelbarrow. The vehicle or vehicles will be equipped with sleeping accommodation for at least 50 people.

Confronting Bureaucracy

Either way, the trip will be challenging, not only because of the physical effort involved, but also because of many other obstacles, from bridges over telephone lines to rules and regulations. Time Circus wants to “obtain freedom of movement by gently opposing regulations with inventiveness and the use of the grey areas of the law, confronting the bureaucracy in a playful and witty way.”

The slowness of the journey gives ample space for meetings and interaction along the road. The main message of the project is to demonstrate that “unexpected forces can develop through cooperation”. It also wants to “encourage the imaginative forces in the world, introducing alternatives that lie dormant”.

More info: Time Circus. There’s also a video (in Dutch).

Low tech? Wild tech!

Tue, 11/28/2017 - 02:17

The French scientific magazine Techniques et Culture has published an entire volume about alternative forms of technology: “Low-tech? Wild tech!“. The 300-page issue explores the differences and conflicts between high-tech and low-tech, with a focus on all the forms of technology which are in between these extremes.

The authors argue for a more sophisticated view of technological evolution, which is now usually seen as linear progress towards ever increasing complexity and perfection. The contributions show that reality is much more complicated, and much more interesting.

The issue is the fruit of a three-day discussion in Paris in 2012, in which I participated. The volume features a translated article from Low-tech Magazine: “How to build a low-tech Internet?”. “Low tech? Wild tech!” will be presented and discussed in Paris on December 9, 2017.

Prototype of a Hydro-Pneumatic Human Power Plant

Mon, 09/18/2017 - 15:11

The Human Power Plant is a working prototype of a muscular power generator, manned by a group of people. It is an all-round off-the-grid solution, which can supply energy in the form of electricity, water under pressure, and compressed air. It is built from simple and durable parts.

These days, we have automated and motorised even the smallest physical efforts. At the same time, we go to the gym to keep in shape, generating energy that’s wasted. The Human Power Plant restores the connection between physical exercise and energy use.

See and read more: The Hydro-Pneumatic Human Power Plant: How it Works. Drawing: Melle Smets.

Restore the Night Trains in Europe

Mon, 09/18/2017 - 14:57

The French passenger association “Oui au train de nuit” (“Night trains yes!”) has compiled a report about European night trains: “Put the night trains back on track“. During the last five years, most of Europe’s night trains have disappeared, although they are popular with travelers and the only alternative to the airplane.

* The report was brought to our attention by Back on Track, a European coalition that supports cross-border rail and brings the latest news about international passenger travel in Europe. * Previously: High speed trains are killing the European railway network. * Picture taken from the back window of the night train Madrid – PortBou in 2013.

Non-Electric Hearing Aids Outperform Modern Devices

Thu, 08/24/2017 - 19:36

Most people with hearing problems are not using hearing aids, mainly because the electronic devices often do not provide enough benefit. Research shows that non-electric hearing aids from earlier centuries are performing significantly better.

Digital Hearing Aids

Roughly 40% of people between the ages of 55 to 74 suffer hearing loss. Eighty percent of them do not wear a hearing aid, even though their disability often has a negative impact on their quality of life as well as others around them. According to a 2013 research paper, the main reason is the limited performance of the devices.

Interestingly, these results are in line with those of studies performed at the end of the twentieth century, meaning that the introduction of digital hearing aids has had no positive effect on the popularity of the technology. Electric hearing aids consist of a battery, a microphone, an amplifier and a speaker. The more compact electronic hearing aids also contain a microchip.

An additional obstacle in poorer countries is the cost of the technology, which concerns the device as well as the batteries, which need to be replaced regularly. Worldwide, roughly 1 billion people suffer from hearing loss. According to the World Health Organisation, only one fifth of them wears a hearing aid.

Ear Trumpets & Speaking Tubes

From the seventeenth century onwards, several types of non-electric hearing aids were developed, based on different acoustical principles. The most important devices were ear trumpets and speaking tubes.

An ear trumpet

In the ear trumpet, sound from a funnel-shaped metal tube was conducted to a small opening that was inserted in the listener’s ear. Ear trumpets were often slighty curved at one end so that they could be aimed at the sound source more easily. Some models were collapsible for easy carrying.

The speaking tube consisted of a flexible tube with a funnel-shaped opening on one end through which the speaker could talk, while the other end of the tube was put in the ear of the listener.

Stationary Hearing Aids

Speaking tubes and ear trumpets were also combined, especially in stationary hearing aids such as the acoustical chair. This seating had a pair of large trumpets on each side, which amplified the sound and led it through flexible tubes to the listener’s ears.

Similar technology could also be hidden in objects like vases. This was meant for several speakers and listeners gathering around a table. In the days before the telephone, speaking tubes were also used by people with normal hearing to communicate between floors of a building or a ship.

Sound Amplification

Measurements from the late twentieth century show that these devices perform better than today’s high-tech hearing aids. Ear trumpets and speaking tubes not only yielded a sound amplification of 10 to 25 decibels, they also suppressed sounds that came from other directions, further improving their workings. The speaking tube also reduced the noise reduction between speaker and listener.

A speaking tube

Another important advantage was that both devices were very visible and thus encouraged the speaker to talk slower and more clearly. However, this visibility was also considered to be a problem: well-functioning, non-electric hearing aids are laughable.

From the nineteenth century onwards, the development of hearing aids took another direction: much smaller ear trumpets and speaking tubes were now hidden in clothing and accessories.

Vanity

The most popular models were worn as a kind of headband, with small trumpets hidden behind the ears, in hats, wigs, beards or scarfs. An extra advantage was that these devices could be operated hands free. Unfortunately, these hearing aids had poor performance compared to earlier models, and sometimes even impaired hearing.

However, a new trend was set. Since the nineteenth century, the main criterium for a hearing aid is no longer its effectivity but its discretion and compactness. Nevertheless, those who can overcome their vanity can revert to technology that has proven to work.

A large collection of images showing non-electric hearing aids can be found at the Bernard Becker Medical Library Image Gallery.

Sources:

Digital Colonialism

Fri, 07/28/2017 - 11:28

Free Basics, Facebook’s free, limited internet service for developing markets, is neither serving local needs nor achieving its objective of bringing people online for the first time.

“Facebook is not introducing people to open internet where you can learn, create and build things,” said Ellery Biddle, advocacy director of Global Voices. “It’s building this little web that turns the user into a mostly passive consumer of mostly western corporate content. That’s digital colonialism.”

Read more: How Facebook’s free internet service has failed its users.
Previously: How to build a low-tech internet.

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