≡ Menu

We’re Back Online

We apologize for the inconvenience as Low-tech and No Tech Magazine were down for most of the last six days, following a cyber-attack on our host TypePad. We managed to move No Tech Magazine to another host yesterday, and posting will resume shortly. We are in the process of moving Low-tech Magazine, but for the time being the main blog is still on TypePad, which seems to be back online at least for now.

The Axe Has Been Reinvented

“Chopping firewood with traditional axes is often a laborious and even dangerous task. There is always the risk of hitting your own leg with the axe. From this imperfect situation began the pursuit to develop a better axe. It took several years, thinking and testing different exotic methods of chopping wood that were available for purchase at the time, before the idea was born. The traditional axe uses a wedge-shaped head to split the wood, but could this mechanism be improved by using leverage? From this idea the new axe was born, the Leveraxe.

Leveraxe

The operational principle of the Leveraxe is totally different from the traditional axe. Upon hitting the top of the log and penetrating it slightly, the leading edge of the axe head begins to slow down. Where the axe blade widens sharply it stops the axe’s penetration. However, the mass of the axe head still has kinetic energy and the off line center of gravity forces it to rotate eccentrically down towards the wood. This rotational movement causes the leading edge, or sharp edge of the blade to turn in a lever action, forcing a split with all the force of the kinetic energy of the axe multiplied by the leverage of the axehead. The widening blade edge also has a benefit in that it helps to prevent the axe from penetrating into the wood and getting stuck there as is often the case with traditional axes.

The 1.9kg axe head has a significant amount of kinetic energy when it begins the rotational movement. While the centre of gravity of the head continues first to the right and then downwards the edge moves in a rotational direction to the left. This movement uses the rotational torque to split a log and push it away from the wood. In total the edge opens the wood by 8 cm. When the axe has rotated sideways it has used most of its energy and ends on top of the log on the in a sideways fashion. This safety feature ensures that the axe does not continue towards your legs and the axe remains totally in control. In addition, the axe holds the log steady on the chopping block ready for the next swing.”

The Finnish Leveraxe. Via Boing Boing and Hackernews. Thanks to Thomas Varney and Brice Waegenire. 

“The biomass power industry is undergoing a new surge of growth in the United States. While bioenergy has traditionally been used by certain sectors such as the paper-making industry, more than 70 new wood-burning plants have been built or are underway since 2005, and another 75 proposed and in various stages of development, fueled by renewable energy subsidies and federal tax credits. In most states, biomass power is subsidized along with solar and wind as green, renewable energy, and biomass plant developers routinely tell host communities that biomass power is “clean energy.”

Teesside biomass power plant

Promotional photo of BEI-Teesside, a planned biomass power plant in the UK. The volcanoe shape is well chosen if you consider the pollution that is produced by biomass power plants.

But this first-ever detailed analysis of the bioenergy industry reveals that the rebooted industry is still a major polluter. Comparison of permits from modern coal, biomass, and gas plants shows that a even the “cleanest” biomass plants can emit > 150% the nitrogen oxides, > 600 % the volatile organic compounds, > 190% the particulate matter, and > 125% the carbon monoxide of a coal plant per megawatt-hour, although coal produces more sulfur dioxide (SO2). Emissions from a biomass plant exceed those from a natural gas plant by more than 800% for every major pollutant.

Biomass power plants are also a danger to the climate, emitting nearly 50 percent more CO2 per megawatt generated than the next biggest carbon polluter, coal. Emissions of CO2 from biomass burning can theoretically be offset over time, but such offsets typically take decades to fully compensate for the CO2 rapidly injected into the atmosphere during plant operation.”

Read the report: Trees, Trash, and Toxics: How Biomass Energy Has Become the New Coal (PDF), Mary S. Booth, Partnership for Policy Integrity, April 2, 2014. Via biofuelwatch.

Walking Made Us Fly

“The first time I went on a really long walk, an absurd six-day walk following the exact border of a municipality in the east of the Netherlands, walking through fields, crossing canals, entering peoples’ houses, sleeping on the border in a small tent, I felt the way I had felt as a kid when I went out exploring the vast forest behind my parents’ house.

Some people would rather have wings but we don’t, we have feet. We were born to walk. Scientists say that walking gave us our brain capacity, walking turned us into the human beings we are. Walking made it possible for us to have the desire to fly and to come up with ways to turn our dreams into reality.

Walking made us fly. We can go anywhere. Still the easier it becomes to move through this world, the more disconnected we seem to get from it. We have to land again. Get close to the things. Be part of the world. Walking teaches us where we are, who we are. A slow speed makes our brain work fast. Makes us see more. Be more. And best of all: walking makes time disappear.”

Read more: A Soft Armour by Monique Besten. Previously: Our Right to be Oustide.

A Tourist Monoculture

Barcelona tourism 5

“This is not a city to live in. It’s a theme park where there’s no local life left. It’s all decoration.”

“Tourism is not going to be forever, and it’s destroying other ways of life.”

“We cannot live with those floods of people day after day.”

These are some quotes from Bye Bye Barcelona (59m, with English subtitles), a shocking documentary about tourism’s destructive effect on the culture of a city. Barcelona in Spain is the fourth most visited city in Europe after London, Paris and Rome, yet it is much smaller than those cities. The 1.5 million Barcelonians received more than 8 million tourists in 2013, most of them flown in by low-cost airlines. This compares to “only” 3.1 million tourists in 2000.

Bye Bye Barcelona, Eduardo Chibas, March 2014. Thanks to Adriana Parra.

The word “sari” means a strip of cloth. Historic literature points towards the use of this garment even during the Indus Valley civilization in circa 3000 BC. India has a very long and rich textile tradition. The saris vary in style, material and embellishment across the regions and cultures. A recent large-scale yearlong field study in 28 Indian offices has shown that 99% of Indian women are dressed in Indian ensembles. However, knowledge on the sari’s clothing insulation is very limited in the current codes. ASHRAE standards carry the clo values of many western-style ensembles only.

The sari in its modern day avatar is a single rectangular piece of unstitched cloth: 1.15 – 1.25 m wide and 5 to 8.1 m long. The draping style of sari varies with geographical area and the activity of the female, while there are more than a hundred known styles of draping. A unique feature of sari is that it changes the insulation level significantly just by adjusting the drapes, and there are many ways to drape the upper body and lower body. The drape of the ensemble depends on several factors including weather, occassion, and activity of the person and it alters the microclimate around various body parts.

Sari clothing insulation

The steps of sari draping in “nivi” style. Source: Saris: An Illustrated Guide to the Indian Art of Draping (PDF), C. Boulanger, 1997.

For this study we used the most popular “nivi” style of draping along with its four subvariations using two 5.75 m long saris. We draped a female manikin in two different saris. These are (1) a heavy weight poly-cotton handloom sari, and (2) a lightweight pure silk sari made in the Indian states of Karnataka and Tamilnadu respectively. All together, we tested nine combinations of ensemble/drapes commonly observed in office buildings in both winter and summer.

Unlike the western outfits, the sari was found to be a unique ensemble offering a range of clothing insulation, rather than a single value for a given set of garments of the ensemble depending on the drape. We noted the clothing insulation varying by about 35% due to the changes in drape on the upper body alone. The winter ensembles had a clothing insulation of 1.11 to 1.39 clo, while the summer and monsoon ensembles provided 0.62 to 0.96 clo as clothing insulation.

Quoted from: Versatile Indian sari: Clothing insulation with different drapes of typical sari ensembles, Madhavi Indraganti et al, Proceedings of 8th Windsor Conference: Counting the Cost of Comfort in a Changing World, Cumberland Lodge, Windsor, UK, 10-13 April 2014. London: Network for Comfort and Energy Use in Buildings. Many thanks to Elizabeth Shove.

Related posts:

The Dobsonian Telescope

The dobsonian telescope“The design of this telescope is called a Dobsonian, after its inventor John Dobson, who passed away earlier this year. Dobson’s life took an unusual trajectory. He went from being a self described “belligerent atheist” to a monk in the Vendanta society to co-founding the San Francisco Sidewalk Astronomers.  Most of his life was spent bringing the night sky to people around the world and teaching people how to make their own low-cost telescopes.

As a monk, Dobson could not afford expensive materials. He kept the design inexpensive by using a simple mount and cheap materials: wood and cardboard. My Dobsonian was made by the now defunct Coulter Optical Company out of particle board and a cardboard concrete form. Its large 13.1 inch mirror makes it perfect for looking at nebulas, galaxies and star clusters even in light polluted urban areas.”

Find out more. Illustration.

In a time when cloth-making was one of the most advanced technologies, a piece of square cloth was all that a man needed to carry goods around. Japanese call it ‘Furoshiki’, a square cloth that with different wrapping techniques can basically transport anything. With its name meaning ‘bath spread’, Furoshiki is a traditional kind of wrapping cloth made of natural materials like silk and cotton. It is believed to date back to the 8th century. What was at first used to wrap up noblemen’s clothes in bathhouses gradually transported goods and gifts.

060403-5

Click to enlarge. More pictures here.

Modern bags might have outshone Furoshiki, but recent years have seen its comeback as a green alternative to shopping bags, thanks to the ‘Mottainai Furoshiki’ initiative by Yuriko Koike, Japan’s Minister of the Environment, in 2006. “It’s a shame for something to go to waste without having made use of its potential in full,” said Koike. Like what beauty label LUSH has followed to produce, the modern Furoshiki Koike upheld was made of recycled PET bottles that, as the Minister put it, “can wrap almost anything in it regardless of size or shape with a little ingenuity by simply folding it in a right way.”

The above graph demonstrating different wrapping techniques went viral on the internet. A wave of shops emerged to sell fancy furoshiki. The Minister’s statement holds some truism because a furoshiki does wrap up almost anything of all shapes and fragility – from vegetables to bottles, from wine glasses to eggs, from a baby to a dog. Besides its diversity, Furoshiki is a great alternative to adopt also because of its portability, leaving almost no room for excuses like ‘I forgot to bring my own bag’. Most of the time very decorative because Japanese treat it as an artistic craft, a furoshiki makes a great scarf, headband or pocket square. 

Ren wanLight and small, it comfortably fits in your pocket or day bag, whilst some furoshiki clothes are big enough to a bag whose form you can change every other day. A personal experiment proves that it helps encourage shoppers to opt for less- or un-packaged options. To avoid unnecessary packaging I visit local grocery stores for unpackaged tomatoes and to the plastic bag addicts’ surprise, it is very easy and light to transport. Just think about how one piece of cloth has the potential to replace all shopping bags. Does it not make it one of the smartest solution to shopping bags and excessive packaging?

This is a guest post by Ren Wan, a writer and sustainability advocate who is based in Hong Kong. She runs JupYeah, an online swapping platform, is a managing editor for WestEast Magazine, and blogs at Loccomama.

Solar Powered Grain Mill

“Graining cereal crops is a basic, century old business and it will continue to be as important as ever before for centuries to come. Before the age of oil grain milling was entirely based on renewable energy. It was either done by wind energy, hydropower, animals or manpower. For the last century the traditional grain milling has been mainly replaced by electricity and fuel driven milling.”

Solar milling

“The Solar PV Grain Mill works to the same principle like any conventional, electrically driven mill. The mill has a very efficient 3-phase AC motor which is directly coupled to the graining system. The main invention of the system is, and that makes it unique among PV systems, that it is a “direct drive system” without the need of batteries. The Solar PV generator converts solar radiation into electricity, and the generated electricity is directly feeding the motor drive. There are no additional conversion losses, such as energy storage losses in batteries, battery maintenance or replacement costs, which are a common problem in conventional Solar PV off-grid systems.”

Read More: Solar Milling. Via Engineering for Change.

I would like to add that the direct drive system also eliminates the high energy use caused by the production of the batteries, which can make solar PV off-grid systems everything but sustainable. Therefore, storing work instead of energy — the solar mill only operates when the sun shines — is a very interesting strategy in sunny regions.

Related:

Atlas of environmental justice

“Across the world communities are struggling to defend their livelihoods from damaging environmental impacts. Mining projects, mega dams, tree plantations, fracking, gas flaring, incinerators, etc … As resources needed to fuel our economy move through the commodity chain from extraction, processing and disposal, environmental impacts are externalized onto the most marginalized populations. But all this takes place far from the eyes of the consumers of the end-products. The Environmental Justic atlas aims to make these impacts more visible and to make the case for true corporate and state accountability for the injustices inflicted through their activities.”

“The map tells a story of environmental devastation and despoliation, of ecocide and eco-apartheid, but also a story of resistance, and communities mobilizing to fight against the odds. Of the cases currently in the map, 17% are successes for environmental justice. Court cases were won, communities were strengthened, and access to the commons was reclaimed. These victories are a testament to the power of protest and the ability to impact the political process. We don’t aim to “solve” the conflicts but to reveal the actors and drivers and structural patterns behind them. The defense of territory, the defense of livelihood and the defense of the resources that communities depend on are the best weapon against endless capitalist exploitation of the ecological system we depend on.”

The Atlas of Environmental Justice.