Manganese dioxideManganese dioxide is the inorganic compound with the formula MnO2. This blackish or brown solid occurs naturally as the mineral pyrolusite, which is the main ore of manganese and a component of manganese nodules. The principal use for MnO2 is for dry-cell batteries, such as the alkaline battery and the zinc–carbon battery. MnO2 is also used as a pigment and as a precursor to other manganese compounds, such as potassium permanganateKMnO4. It is used as a reagent in organic synthesis, for example, for the oxidation of allylic alcohols.
Optimal designIn the design of experiments, optimal designs (or optimum designs) are a class of experimental designs that are optimal with respect to some statistical criterion. The creation of this field of statistics has been credited to Danish statistician Kirstine Smith. In the design of experiments for estimating statistical models, optimal designs allow parameters to be estimated without bias and with minimum variance. A non-optimal design requires a greater number of experimental runs to estimate the parameters with the same precision as an optimal design.
Species reintroductionSpecies reintroduction is the deliberate release of a species into the wild, from captivity or other areas where the organism is capable of survival. The goal of species reintroduction is to establish a healthy, genetically diverse, self-sustaining population to an area where it has been extirpated, or to augment an existing population. Species that may be eligible for reintroduction are typically threatened or endangered in the wild.
In-situ conservation in IndiaIn-situ conservation is the on-site conservation or the conservation of genetic resources in natural populations of plant or animal species, such as forest genetic resources in natural populations of Teagan species. This process protects the inhabitants and ensures the sustainability of the environment and ecosystem. About 4% of the total geographical area of the country is used for in situ conservation. The following methods are presently used for in situ conservation. Biosphere reserves cover very large areas, often more than 5000 km2.
Leclanché cellThe Leclanché cell is a battery invented and patented by the French scientist Georges Leclanché in 1866. The battery contained a conducting solution (electrolyte) of ammonium chloride, a cathode (positive terminal) of carbon, a depolarizer of manganese dioxide (oxidizer), and an anode (negative terminal) of zinc (reductant). The chemistry of this cell was later successfully adapted to manufacture a dry cell. In 1866, Georges Leclanché invented a battery that consisted of a zinc anode and a manganese dioxide cathode wrapped in a porous material, dipped in a jar of ammonium chloride solution.
