The human eye is an organ that reacts to light and allows vision. Rod and cone cells in the retina allow conscious light perception and vision including color differentiation and the perception of depth; the human eye can differentiate between about 10 million colors and is capable of detecting a single photon. The eye is part of the sensory nervous system. Similar to the eyes of other mammals, the human eye's non-image-forming photosensitive ganglion cells in the retina receive light signals which affect adjustment of the size of the pupil and suppression of the hormone melatonin and entrainment of the body clock; the eye is not shaped like a perfect sphere, rather it is a fused two-piece unit, composed of the anterior segment and the posterior segment. The anterior segment is made up of the cornea and lens; the cornea is transparent and more curved, is linked to the larger posterior segment, composed of the vitreous, retina and the outer white shell called the sclera. The cornea is about 11.5 mm in diameter, 0.5 mm in thickness near its center.
The posterior chamber constitutes the remaining five-sixths. The cornea and sclera are connected by an area termed the limbus; the iris is the pigmented circular structure concentrically surrounding the center of the eye, the pupil, which appears to be black. The size of the pupil, which controls the amount of light entering the eye, is adjusted by the iris' dilator and sphincter muscles. Light energy enters the eye through the cornea, through the pupil and through the lens; the lens shape is controlled by the ciliary muscle. Photons of light falling on the light-sensitive cells of the retina are converted into electrical signals that are transmitted to the brain by the optic nerve and interpreted as sight and vision; the size of the eye differs among adults by two millimetres. The eyeball is less tall than it is wide; the sagittal vertical of a human adult eye is 23.7 mm, the transverse horizontal diameter is 24.2 mm and the axial anteroposterior size averages 22.0–24.8 mm with no significant difference between sexes and age groups.
Strong correlation has been found between the width of the orbit. The typical adult eye has an anterior to posterior diameter of 24 millimetres, a volume of six cubic centimetres; the eyeball grows increasing from about 16–17 millimetres at birth to 22.5–23 mm by three years of age. By age 12, the eye attains its full size; the eye is made up of layers, enclosing various anatomical structures. The outermost layer, known as the fibrous tunic, is composed of the cornea and sclera, which provide shape to the eye and support the deeper structures; the middle layer, known as the vascular tunic or uvea, consists of the choroid, ciliary body, pigmented epithelium and iris. The innermost is the retina, which gets its oxygenation from the blood vessels of the choroid as well as the retinal vessels; the spaces of the eye are filled with the aqueous humour anteriorly, between the cornea and lens, the vitreous body, a jelly-like substance, behind the lens, filling the entire posterior cavity. The aqueous humour is a clear watery fluid, contained in two areas: the anterior chamber between the cornea and the iris, the posterior chamber between the iris and the lens.
The lens is suspended to the ciliary body by the suspensory ligament, made up of hundreds of fine transparent fibers which transmit muscular forces to change the shape of the lens for accommodation. The vitreous body is a clear substance composed of water and proteins, which give it a jelly-like and sticky composition; the approximate field of view of an individual human eye varies by facial anatomy, but is 30° superior, 45° nasal, 70° inferior, 100° temporal. For both eyes combined visual field is 200 ° horizontal, it is 13700 square degrees for binocular vision. When viewed at large angles from the side, the iris and pupil may still be visible by the viewer, indicating the person has peripheral vision possible at that angle. About 15° temporal and 1.5° below the horizontal is the blind spot created by the optic nerve nasally, 7.5° high and 5.5° wide. The retina has a static contrast ratio of around 100:1; as soon as the eye moves to acquire a target, it re-adjusts its exposure by adjusting the iris, which adjusts the size of the pupil.
Initial dark adaptation takes place in four seconds of profound, uninterrupted darkness. The process is nonlinear and multifaceted, so an interruption by light exposure requires restarting the dark adaptation process over again. Full adaptation is dependent on good blood flow; the human eye can detect a luminance range of 1014, or one hundred trillion, from 10−6 cd/m2, or one millionth of a candela per square meter to 108 cd/m2 or one hundred million candelas per square meter. This range does not include looking at the midday lightning discharge. At the low end of the range is the absolute threshold of vision f
Whenever, If Ever is the debut studio album by American indie rock band The World Is a Beautiful Place & I Am No Longer Afraid to Die released on June 18, 2013 on Topshelf Records. All music is composed by The World Is a Beautiful I Am No Longer Afraid to Die. Thomas Diaz – vocals, synthesizer David Bello – vocals Nicole Shanholtzer – guitar, vocals Joshua Cyr – bass guitar, synthesizer Katie Shanholtzer-Dvorak - synthesizer, vocals Steven Buttery – percussion Christopher Teti – guitar Julia Peters – cello Patrick Malone – trumpet Greg Horbal – guitar, piano, synthesizer
ProLiant is a brand of server computers, developed and marketed by Compaq. After Compaq merged with Hewlett-Packard, HP retired its Netserver brand in favor of the ProLiant brand; the brand is marketed by Hewlett Packard Enterprise. HP ProLiant systems led the x86 server market in terms of units and revenue during first quarter of 2010. Proliant servers offers advanced capabilities such as dual power supplies with redundant configuration support. ML server models are tower-based, they aim towards maximum expandability. DL server models are rack-based, they aim towards a balance between computing power. SL server models are rack-based; these models are used in data centers and environments where a maximum of computing power is desired. BL server models are enclosure-based, they can not be used without such. Blade systems aim towards maximum manageability at limited rack space. There are two models of blade enclosures: HPE BladeSystem c3000 Enclosure, HPE BladeSystem c7000 Enclosures. One advantage of HP/HPE Blade Enclosures compared to competitors has been that the older generation enclosures have been able to accommodate new generation BL servers just by upgrading the firmware for OA in the enclosure.
However improvements to back-plane of the enclosure in the new generation enclosures have enabled faster I/O capabilities. The physical design of the enclosures has not changed since the first versions; the HPE ProLiant MicroServer line of products are entry-level, low power and affordable servers meant for small business, home office, or edge computing. They offer easy access to hard drives. There is the option to purchase the server with ClearOS installed in order for users to be able to enable applications via an easy-to-use web-GUI with minimal effort. ProLiant servers are separated into four main product lines - ML, DL, BL, SY, Apollo - which denote form factor; the ProLiant ML line comprises tower-based servers with capacity for internal expansion of disks and interconnects, while the DL line comprises general purpose rack mount servers. The BL line comprises blade servers which fit within the HP BladeSystem, the SY comprises the Synergy Blades, the Apollo line comprises servers for scale out and High Performance Computing environments.
The MicroServer product line addresses small and home businesses. ProLiant servers are split into several series which denote processor configuration; the 100, 200, 300 and 400 series comprise single and dual socket capable systems, the 500 and 600 series comprise quad socket capable systems, the 700 and 900 series comprise eight socket capable systems. The 900 series supports up to 80 CPU cores and up to 4 TB of RAM. Models with a'0' in the last digit use Intel processors while models with a'5' in the last digit use AMD processors; the ProLiant forms part of the HP Converged Systems, which use a common Converged Infrastructure architecture for server and networking products. Designed to support 50 to 300 virtual machines, the HP ConvergedSystem 300 is configured with ProLiant servers. A system administrator can manage ProLiant servers using HP OneView for converged infrastructure management.. HP provide drivers a software for managing servers such as Management Component Pack which includes hp online configuration utility, Agentless Management Service amsd, Smart Storage Administrator ssa, Smart Storage Administrator CLI ssacli and Smart Storage Administrator Diagnostic Utility CLI ssaducli.
In February 2012, HP announced the ProLiant generation 8. In July 2013, HP announced the HP Moonshot Server. DL580 Gen8 is a "middle generation" between Gen8 and Gen9; this server has some of new features introduced in Gen9, primary there is available UEFI boot option. Starting August 28, 2014, HP Proliant Gen9 series were available based on Intel Haswell chipset and DDR4 memory. First were HP ProLiant BL460c Gen9 Blade. Servers in this generation support both BIOS and UEFI. Starting Q4 2017 HP Proliant Gen10 servers were available; that year in November HPE extended their Gen10 range to include AMD EPYC processors to further economics in server virtualization using EPYC's impressive price v cores architectures claiming to lower cost per virtual machine by 50%. HP Integrity Servers List of Hewlett-Packard products Official website