Disk drives

For most users, the serial port is the major data artery of the computer. As the connection point for disk drives and printers, it s the port through which most information exchanges take place. This is the one port that is the same on the Commodore 128, 64, VIC-20, Plus/4, and 16. Well, almost the same—there are some signal timing differences. (The VIC-20 transfers data at a slightly faster rate than the others, which is why the VIC is listed as incompatible with some Commodore printers, and why the original 1540 disk drive was only for the VIC.) How-... 

Dis] oining pressure Disk brakes Disk drives Disk memories Disk nulls Disks... 

Another advantage of PC technology is the plaimed and partially realized use of multiftmction drives for operation of either CD-ROM, WORM, or PC-R disks alternatively in the same disk drive. This is technically feasible, since for reading (in CD-ROM, WORM, PC-R) as well as for writing (WORM, PC-R) similar principles and hardware are used (108). However, the reflectivity change of PC disks (40/70%) is in general lower than the CD-ROM standard (30/70%) requires. 

Mass storage device. Typically, fixed-head hard disk drives are used to store ac tive data, including on-line and historical databases and non-memory-resident programs. Memory-resident programs are stored to allow loading at system startups. The tape drives are used for archives and backups. 

Another important application area for PSAs in the electronic industry focuses on the manufacturing, transport and assembly of electronic components into larger devices, such as computer disk drives. Due to the sensitivity of these components, contamination with adhesive residue, its outgassing products, or residue transferred from any liners used, needs to be avoided. Cleanliness of the whole tape construction becomes very critical, because residuals like metal ions, surfactants, halogens, silicones, and the like can cause product failures of the electronic component or product. Due to their inherent tackiness, acrylic PSAs are very attractive for this type of application. Other PSAs can be used as well, but particular attention has to be given to the choice of tackifier or other additives needed in the PSA formulation. The choice of release liner also becomes very critical because of the concern about silicone transfer to the adhesive, which may eventually contaminate the electronic part. 

SCREEN will run on an IBM-PC compatible personal computer with at least 2S6K of RAM. The program will run with or without a math coprocessor chip. Execution time will be greatly enhanced with a math coprocessor chip present (about a factor of S in computer time) and will also benefit from the use of a hard disk drive. 

Computerizes MSDSs in OSIlA-174 format., tracks material use and storage. Requires 448K memory and 2 disk drives. 

THERMOSIM Module 1 EQUIL Gulf Publishing Company, Book Division Melissa Beck P.O. Bo 2608 Houston, TX 77252 (713) 520-4444 Database of thermodynamic properties of 200 hydrocarbons, 9 non-bydrocaibon gases, carbon, and sulfur. Requires 512K memory and 2 disk drives. 

Electric motors are eveiywhere. These ubiquitous devices come in a wide variety of sizes and power outputs, ranging from a fraction of a watt to huge multikilowatt applications. Tiny ones operate computer disk drives, power windows/mirrors, and windshield wipers moderate-sized ones run appliances such as fans, blenders, electric shavers, and vacuum cleaners a large drive pumps, elevators, sawmills, and electric trains and vehicles. 

Even when the time comes to make a purchasing decision, an energy-efficient motor purchase is not a certainty. Sometimes an energy-efficient motor will be the economically efficient choice at other times, not. The capital investment decision is based on the cost in relation to performance, efficiency and reliability. Moreover, the decision depends on the application and the amount of time the motor is in operation. It can be the major component of a product (drill or mixer), or a minor component (computer disk drive) it can be the major component cost of a product (fan), or it can be a minor component cost (stereo tape deck) it can run almost constantly (fan, pump, and machinery), or only a few minutes a day (vacuums and power tools). For example, contractors purchase circular saws almost solely based on performance and reliability. Time is money, and since the saw is operating only a few minutes a day and the contractor is often not responsible for the electricity costs to run the motor, energy efficiency is not a consideration performance and reliability are what matter most. On the other hand, an industrial user, who runs huge electric motors twenty-four hours a day to work pumps, machinery, and ventilation equipment, is very concerned tvitli energy efficiency as well as performance and reliability. 

Wu, L., and Bogy, D. B., Numerical Simulation of the Slider Air Bearing Probiem of Hard Disk Drives by Two Multi-dimensionai Unstructured Triangular Meshes," /. of Computational Physics, Vol. 172,2001, pp. 640-657. 

However, investigations up to now have mainly concentrated themselves on ambient environments even though it is known that ionic liquids have a very low vapor pressure, making them suitable for vacuum applications such as in space mechanisms, the disk drive industry, and microelec-tromechanical systems (MEMS). Due to the ultra-low vapor pressure of most ionic liquids, they have been expected to be good lubricants in vacuum. Further experimental works are required to evaluate lubrication behavior of ionic liquids under ultra-high vacuum conditions and in inert atmospheres. 

Yang, M. C., Study on Nano-Tribology at Head/Disk Interface of Computer Hard Disk Drives," Ph.D. Thesis, Tsinghua University, Beijing, China, 2001. 

IDEMA (The International Disk Drive Equipment and Materials Association), Disk Drive Technology, IDEMA, 2000, pp. 

A computer disk drive is composed of many layers. The primary layer is made of aluminum and is 1.0 mm thick. If the diameter of an aluminum atom is 2.5 angstroms, how many aluminum atoms thick is the primary layer ... 

A computerized laboratory can utilize a software package called a laboratory information and management system (LIMS) to carry out or control all of these requirements provided that computerized instrumentation, computer terminals, printers and plotters, disk drives etc. are linked together in a local... 

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