Directory of Open Access Journals

Open access journals“The aim of the Directory of Open Access Journals is to increase the
visibility and ease of use of open access scientific and scholarly
journals thereby promoting their increased usage and impact. The
Directory aims to be comprehensive and cover all open access scientific
and scholarly journals that use a quality control system to guarantee
the content. In short a one stop shop for users to Open Access Journals.”

Especially interesting for Low-tech and No Tech Magazine readers are the journals in the categories History, Archaeology, Technology & Engineering, and Earth and Environmental Sciences.

Dedicated to Aaron Swartz. Also: #PDF Tribute to Aaron Swarz (via TechCrunch), a mass protest uploading of copyright-protected research articles. Previously: Censors of Knowledge.

Earthen Solar Cooker

earthen solar cooker

“The Earthern Solar Cooker is a large parabolicly shaped hole in the ground lined with reflective materials such as salvaged pieces of broken mirrors or reflective can lids. The mirrors reflect and concentrate sunlight to the base of the hole where ten one gallon black containers of water can be boiled per hour and used for drinking or food preparation. Cooking/water boiling containers are accessed via steps carved into the side of the Earthen Solar Cooker.”

“A 2.5m diameter hole, 1.5m deep cooks 10 gal of rice/hr from 11am to 3pm on an 85f summer day in south central Oregon. Since the power of a parabolic concentrator is proportional to the surface area of it’s aperature (A = 3.14 x r^2), doubling the radius of the hole increases the power of the Earthen Solar Cooker by a factor of four.”

“An Earthen Solar Concentrator the size of a small amphitheater might be capable of casting bronze or boiling the water near the surface of a shallow well located at the vertex, thus making possible the creation of a solar bubble pump that could lift pasteurized water to a tank above ground level.” Read more about the project at Appropedia.

Previously:

“Gravity Powered” Lights (and How to Make Them More Powerful)

gravity powered lights

The GravityLight uses a sack of sand or stones to gradually pull a piece of rope through a dynamo mechanism which generates electricity to power an LED. It is a cheaper and more sustainable option than a solar powered light, which requires not only a solar panel but also a battery. The product is aimed at the developing world and its makers raised 400,000 dollars at indiegogo.

The technology could be further improved by including pulley mechanisms that were used to operate human powered cranes and lifting devices in pre-industrial times. This would allow a person to lift heavier weights and thus power more powerful lights.

To be precise, the light is not powered by gravity. It is muscle-powered, while gravity stores the energy and fulfills the role of a battery. Hat tip to Bernd Vleugels.

Abandoned Flour Mill in Spain

Abandoned factories in spainLugares Abandonados is a fascinating blog documenting abandoned buildings in Spain.

There are quite some photo reportages about factories, and this one in particular is noteworthy: a forgotten flour mill with part of the machinery still in excellent condition.

The author does not reveal any location for any of the buildings on the blog.

 

Cargo Cycle for Egg Deliveries

cargo cycle for egg deliveriesThe Pashley Model CT2 is described as “a really handsome, well built and strong light delivery vehicle for confectioners, egg deliveries, grocers, accumulator stations, etc.”

Found at the Museum of Tradesman’s Delivery Bikes, which has a collection of (mostly) English cargo bicycles dating from 1905 to 1982. This is one of the few tricycles on the blog.

Related: Tandem Cargo Tricycle (1940) & More Vintage Dutch Carrier Bikes.

 

DIY Glaciers: a Low-Cost Alternative to Dams

DIY glaciers“A remote Indian village is responding to global warming-induced water shortages by creating large masses of ice to get through the dry spring months. People in Skara and surrounding villages survive by growing crops such as barley for their own consumption and for sale in neighboring towns. In the past, water for the crops came from meltwater originating in glaciers high in the Himalaya. But in recent decades, climate change has uncoupled glacial melt cycles in the Tibetan Plateau from the traditional agricultural season, causing water shortages in April and May when Ladakhis typically begin sowing seeds for the summer season.”

“One winter in the late 1980s, an engineer from Skara named Chewang Norphel came up with a possible solution to his village’s problem while strolling around his backyard. Norphel noticed that a small stream had frozen solid under the shade of a poplar grove, though it flowed freely elsewhere in his sunny yard. The reason for this, he realized, was that the flowing water was moving too quickly to freeze, while the sluggish trickle of water beneath the grove was not. Over the next several years, Norphel worked to create an irrigation system that functioned using the same simple natural principle. The result has been Ladakh’s artificial glaciers. Ten
have been built to date.”

Read more: Artificial Glaciers Water Crops in Indian Highlands.