Tin dioxide with primary particles of diameters from 1 to 10 nm and a distribution with proportional spacing of spherical morphologies were found.
Together they and two teenage girls and a boy in primary school live in a round tin shed, about eight feet in diameter, that was previously used to store tools.
Rwanda's primary exports are coffee, tea, pyrethrum extract, tin, tantalite, and gold.
Dredges have endless bucket chains at one end that dig and lift the tin-bearing ore to the primary processing plant, which is usually located on board.
By 1900 tin completely superseded silver as Bolivia's primary export, accounting for more than half of export earnings.
Already, there are attempts to make this a normal kind of place: whitewashed breezeblock houses with green tin roofs, the Pemex gas station, a primary school, a secondary school.
There are markets in both New York and London for numerous primary goods, including cotton, copper, cocoa, sugar, rubber, coffee, wool and wooltops, tin, silver, and wheat.
Mining and primary-ore processing dominate the economy; minerals and metals produced have included gold, tin, tungsten, molybdenum, lead, zinc, fluorspar, lithium, tantalum, and some lignite (brown coal).
It is a simple building, made of rough plank floors, partial bamboo walls and a tin roof, but it offers the children in the area something they did not have before: a formal primary education.
