Energy & Green Tech

Welcome indoors, solar cells

Swedish and Chinese scientists have developed organic solar cells optimized to convert ambient indoor light to electricity. The power they produce is low, but is probably enough to feed the millions of products that the Internet ...

Energy & Green Tech

Device generates light from the cold night sky

An inexpensive thermoelectric device harnesses the cold of space without active heat input, generating electricity that powers an LED at night, researchers report September 12 in the journal Joule.

Internet

Cell-mostly internet users place privacy burden on themselves

A new report from the Media, Inequality and Change (MIC) Center—a joint project of the Annenberg School for Communication at the University of Pennsylvania and the School of Communication and Information at Rutgers University—details ...

Energy & Green Tech

Researchers set solar record with next-gen cells

Researchers from the Australian National University (ANU) have broken new ground in solar cell energy efficiency and in the process provided a glimpse of the technology's future.

Energy & Green Tech

France climbs aboard hydrogen train revolution

France is joining the hydrogen train revolution, the head of state rail operator SNCF said Thursday, announcing an order for 15 emissions-free regional trains to replace polluting diesel models.

Computer Sciences

Building computers the way our brains work

We are approaching the limit for how much more microprocessors can be developed. Gunnar Tufte proposes building computers in a completely new way, inspired by the human brain and nanotechnology.

Energy & Green Tech

Tiny tweaks for big wins in solar cells

Solar cell performance and stability depend on the morphology of the thin films, especially their ability to crystallize in the so-called photoactive α-phase. Perovskites containing lead tend to combine various halides, ...

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Cell (biology)

The cell is the structural and functional unit of all known living organisms. It is the smallest unit of an organism that is classified as living, and is often called the building block of life. Some organisms, such as most bacteria, are unicellular (consist of a single cell). Other organisms, such as humans, are multicellular. (Humans have an estimated 100 trillion or 1014 cells; a typical cell size is 10 µm; a typical cell mass is 1 nanogram.) The largest known cell is an unfertilized ostrich egg cell.

In 1835 before the final cell theory was developed, a Czech Jan Evangelista Purkyně observed small "granules" while looking at the plant tissue through a microscope. The cell theory, first developed in 1839 by Matthias Jakob Schleiden and Theodor Schwann, states that all organisms are composed of one or more cells. All cells come from preexisting cells. Vital functions of an organism occur within cells, and all cells contain the hereditary information necessary for regulating cell functions and for transmitting information to the next generation of cells.

The word cell comes from the Latin cellula, meaning, a small room. The descriptive name for the smallest living biological structure was chosen by Robert Hooke in a book he published in 1665 when he compared the cork cells he saw through his microscope to the small rooms monks lived in.

This text uses material from Wikipedia, licensed under CC BY-SA