1. a variant spelling (esp US and Canadian) of disc
2. (Computer Science) computing Also called: magnetic diskorhard disk a direct-access storage device consisting of a stack of plates coated with a magnetic layer, the whole assembly rotating rapidly as a single unit. Each surface has a read-write head that can move radially to read or write data on concentric tracks. Compare drum19 See also floppy disk
Usage Have you ever noticed that when you buy a music CD, it is a compact disc, but when you buy a CD in a computer store it is usually a compact disk? Sometimes spelling varies according to how a word is used. Back in the late 19th century, when people were developing the technology for recording sound on a flat plate (what later became the vinyl phonograph record), the inventors referred to the plates as discs, using an alternate spelling of disk. The c spelling eventually became prevalent in the music industry, known for its disc jockeys. When American computer scientists developed flat storage devices back in the 1940s, they chose the common American spelling disk, and this is why we have hard disks installed on our computers. When the storage device known as the compact disk was invented, people in the music industry saw them as shiny substitutes for phonograph records, and they referred to them as compact discs, despite the fact that these same discs were compact disks when they stored nonmusical data. One of the advantages of abbreviations like CD is that they make spelling much simpler!
diskette, floppy, floppy disk - a small plastic magnetic disk enclosed in a stiff envelope with a radial slit; used to store data or programs for a microcomputer; "floppy disks are noted for their relatively slow speed and small capacity and low price"
the part of a computer that is used to pass information onto or from a disk. skyfaandrywer قُرْص дисково устройство unidade de disco disková mechanika das Laufwerk diskdrev; diskettedrev συσκευή σε Η/Υ για ανάγνωση ή/και εγγραφή ψηφιακών δίσκων disquetera kettaseade قسمتی از کامپیوتر که لوح فشرده در آن قرار می گیرد levyasema lecteur de disquettesדיסק डिस्क डाइव, बिम्ब, चकती, डिस्क, मण्डलक disk jedinica, diskovni pogon lemezmeghajtó (számítógépben) penggerak disket unità disco ディスクドライブ 디스크 드라이브 diskavedis diskdzinis bahagian dalam komputer diskdrive, floppydrive platedrevnapęd dyskowy سی دی رم дисковод mechanika disku, disková jednotka računalniški disk disketna jedinica diskettstation, diskettenhet หน่วยขับจานบันทึก (คอมพิวเตอร์) disk sürücü(sü) 磁盤驅動 дисковід صوت نگار آلے میں قرص کو گھمانے والا پرزہ đĩa máy tính 磁盘驱动
In some species (e.g., in the Caridea), blastomeres progressively become superficial and surround an acellular yolk, forming a superficial blastoderm from which a germ disk develops (Anderson, 1973: Dohle et al., 2004; Browne et al., 2005; Klann and Scholtz, 2014; Hertzler, 2015).
The blastomeres ultimately form a blastoderm and a germ disk, from which the embryonic nauplius stage develops (Ishikawa, 1885; Weldon, 1887; Brooks and Herrick, 1891; Nair, 1949; Klann and Scholtz, 2014).
Three possible etiologic mechanisms have been proposed: 1) Mechanical obstruction secondary to compression by amniotic bands, 2) abnormalities of the germ disk, 3) vascular disruption of the fetoplacental circulation.