Practical Answers

• 

  Clay as a Binder

  Clays are the main binders of earth and are made up of very small mineral particles leached out during the erosion of rock.

• 

  Energy from the Wind

  Wind turbines can be used for large-scale energy delivery, but can also be highly effective as small-scale remote applications.

• 

  Hydraulic Lime: An Introduction

  Hydraulic lime was an important cementitious material before the arrival of Portland cement but it is little used now, except in conservation work.

• 

  Lime Production: 2

  Lime has been used in the Malawian building industry for many generations, principally as the cementing agent in renders and to produce a decorative whitewash.

• 

  Producer Gas for Power Generation

  Producer gas is formed by the partial oxidation of a carbonaceous material, such as biomass or coal, in a furnace, generator, or 'producer' unit. This fact sheet outlines the method of doing this, and also other factors to consider like availability of resources and resulting pollutants.

• 

  Drying of Foods

  The drying of food results in longer preservation and ease of transport (lighter). This technical brief describes some of the requirements for food drying to retain maximum nutrients and aesthetics, and summarizes information on the various drying equipment.

• 

  Solar Photovoltaic Energy

  This Technical Brief looks at the background of solar photovoltaic (PV) energy (in which sunlight is directly converted into electricity), the design of PV cell, modules and arrays, and configuration of PV systems.

• 

  Mushroom Growing

  Developing commercial cultivation of mushrooms is growing throughout Africa. This brief focuses on this practice in Zimbabwe.

• 

  Solar Drying

  Drying using sunshine - a brief description of the basic principles behind it and how to determine the rate of drying.

• 

  Ginger Processing

  Ginger is valued for the dried ginger spice and preserved, crystallised ginger.