The San Andreas Fault is a zone several miles wide with multiple strands. The main active strand runs both on and off-shore between Cape Mendocino and the Sea of Cortez. From Cape Mendocino, it runs offshore to Tomales Bay. Then it goes southward through Bolinas Lagoon, just west of the San Francisco Peninsula, to come onshore again at Daly City, through the hills of the Peninsula. Crystal Springs reservoir is formed by the fault itself.
In the Santa Cruz mountains, it bends slightly eastward. This is the site of the 1989 Loma Prieta Earthquake. The fault continues south through the historic mission at San Juan Bautista and through the town of Hollister (where active creep can be seen to offset sidewalks and even houses). The Transverse Ranges north of Santa Barbara are formed by compression. Strands of the fault snake under the Los Angeles Basin. From there it connects into the active spreading under the Sea of Cortez.
The San Andreas fault was discovered by Andrew Lawson in 1895, who climbed into the faulted serpentinite well where the south tower of the Golden Gate Bridge was being poured. In spite of the extreme deformation of the serpentinite, Lawson declared the bridge perfectly safe. The events of the 1906 San Francisco earthquake would seem to support his conclusion: the ruptured strand was not the one he observed in the footprint of the bridge.
Void (astronomy)
In astronomy, voids are the empty spaces between filaments. Both filaments and Voids are one of the largest-scale structures in the Universe. There are no or few galaxies in voids. Most voids have a diameter of 11 to 150 Mpc.
Especially large voids are the empty spaces without many superclusters.
These voids are sometimes called supervoids.
A 1994 official counting (""The structure of the Universe traced by rich clusters of galaxies."", see References) lists a total of 27 supervoids with a distance of up to 740 Mpc. Some of supervoids chosen from the list are given below.
Computer mouse
A computer mouse is an input device that is used with a computer. Moving a mouse along a flat surface can move the cursor to different items on the screen. Items can be moved or selected by pressing the mouse buttons (called clicking). Today's mice have two buttons, the left button and right button, with a scroll wheel in between the two. Today, many computer mice use wireless technology and have no wire.
There are many types of mouse. Optical mouse, wireless mouse, mechanical mouse, trackball mouse. A computer mouse is a handheld hardware input device that controls a cursor in a GUI and can move and select text, icons, files, and folders. For desktop computers, the mouse is placed on a flat surface such as a mouse pad or a desk and is placed in front of your computer. The picture to the right is an example of a desktop computer mouse with two buttons and a wheel. The mouse was originally known as the X-Y position Indicator for a display system and was invented by Douglas Engelbart in 1963 while working at Xerox PARC. However, due to Alto's lack of success, the first widely used application of the mouse was with the Apple Lisa computer.
Today this device is on virtually every computer. The primary function is to move the mouse pointer on the screen. The mouse pointer can be used for many actions on the computer. Clicking or double clicking an icon, folder, or other object will open a document or execute the program. Users can also move an icon, folder, or other object by clicking a mouse button and dragging the object with the mouse pointer. Pointing to an item on the screen means moving your mouse so the pointer appears to be touching the item. When you point to something, a small box often appears that describes the item.
In 1964 Douglas Engelbart (1925-2013), a researcher at Stanford Research Institute, wanted to find a way to make using computers easier. In those days, computers were large and expensive. Using them was very hard because everything had to be typed in on a keyboard. This command line interface is still used by some people, such as programmers, to get things done faster.
After studying and designing for a long time, Engelbart succeeded in inventing an input device which he named 'XY index'. At first, it needed two hands to use, but it was changed so that only one hand was needed to use it. This model was more like the mouse that we use today, but was made up of a big ball that the user had to roll in different directions to move the cursor.
The computer mouse began to be widely used when Xerox Palo Alto Research introduced a GUI in 1981, where the mouse was used to click things on the screen. This was also the case with the Macintosh operating system from Apple of Apple Inc when it came out in 1984, as well as Microsoft Windows. Windows became popular over the years, so over time computer mice became used with many computers.
In 1991, the company Logitech invented the wireless mouse. Unlike a normal mouse, wireless mice were connected by radio signals. Newer wireless mice use Bluetooth or WiFi to connect wireless mice to computers.
On most computers, the user can move the mouse to move the cursor in the same direction. To choose something that is on the screen, the user can move the cursor to it and "click" the left mouse button. The right button is used to open menus that are different depending on where the cursor is. The other mouse buttons can do different things, depending on the software. Most mice have two buttons to click.
Most mice also have the "scroll wheel"—a small wheel found between the two main mouse buttons. The user can move the wheel back and forth to "scroll" through things like a website or folder. "Scrolling" means moving the words or pictures up or down on the screen, so another part of the page comes into view. The wheel can also be pressed, to click it like another button.
A mouse can also be connected to and used the same way with a laptop computer, but unlike a desktop computer, one does not have to be connected to use the laptop. This is because along with the keyboard, laptops have a built-in input device called a trackpad which does the same thing as a mouse. Similarly, tablet computers have a touchscreen as an input device, but some, like the Microsoft Surface and those that use Android, also work with mice.
Metallurgy
Metallurgy is the study of metals. Alloys (mixtures of metals) are also studied. There are two main branches of Metallurgy. They are physical and chemical metallurgy. A Metallurgist is individual who researches, manufactures and develops metal items that range from car parts to semiconductors.
Metallurgists and Metallurgical Engineers often work for consulting engineering firms; mining and manufacturing companies; and in government and universities. Many metallurgists hold a Bachelor of Engineering or similar 4- year degree.
Common Job Tasks
Chemical Metallurgy is the study of extracting and refining metals through chemical reactions. This field also commonly involves corrosion prevention and surface treatment of metals. Scientific concepts such as thermodynamics, the study of heat flow and kinetics, the study of the speed of reactions are very central to chemical metallurgy.
Metallurgists are very interested in the chemical reactions that occur with different elements. Chemical reactions are carried out on a large scale to obtain a useful product.
For example, the production of steel in a blast furnace involves turning different Iron and oxide compounds into pure Iron.
<chem>3Fe2O4 + CO ->2FeO4 + CO2 </chem>
<chem>Fe3O4 + CO -> 3FeO +CO2 </chem>
<chem>FeO + CO ->Fe + CO2
</chem>
Physical metallurgy is the science of making useful properties out of metals. This field focus on the physical property of metals and alloys such as strength and hardness. Properties of metals might be electrical, magnetic and physical in nature. These properties can be changed by alloying or heat treatment.