Chandigarh, Thursday, December 10, 1998 |
Breaking new ground in space propulsion by Radhakrishna Rao THE National Aeronautics and Space Administration (NASA) of the United States which completed four decades of its existence as the worlds premier space research agency, is now busy reorienting its space activities with a thrust on down-to-earth projects. Why Windows 98 is faster
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Breaking new ground in space propulsion by Radhakrishna Rao THE National Aeronautics and Space Administration (NASA) of the United States which completed four decades of its existence as the worlds premier space research agency, is now busy reorienting its space activities with a thrust on down-to-earth projects. According to Daniel Goldin, the chief executive of NASA, expensive space missions are a thing of the past and the cost, scope and diversity of the tasks to be accomplished by future missions must be reduced while scientific performance must be maintained or improved. It is in keeping with this philosophy that the pioneering Deep Space-I probe was launched towards the asteroid 1992 KD. The 490-kg, Deep Space-I during its three years mission will provide NASA engineers an insight into the functioning of ion propulsion driven system and a smart, self navigating mechanism. The currently operational conventional boosters based on the complex and bulky chemicals are pretty costly to operate. As it is, the bulk of the chemicals carried onboard a conventional booster significantly reduces its launch efficiency with the result that such a booster becomes costly to use. On the other hand, the low weight ion propulsion booster make for a greater thrust and cheaper launch. "It is for the first time we are trying something out of the ordinary" quipped Curt Cleven, Deputy Spacecraft of systems manager of Deep Space-I. And as Marc Rayman of NASAs Jet Propulsion Lab (JPL) points out the ion propulsion and autonomous navigation technologies incorporated in Deep Space-I are like having your car finding its own way from Washington DC to Los Angeles and arrive at a designated parking space. Propulsion engineers state that the solar powered ion engines are 10 times more efficient that the chemical fuel driven motor stages used in the currently operational, conventional rockets. An ion propulsion rocket carrying just one tenth the amount of fuel employed in a conventional booster could launch a satellite at a fraction of the cost of the launch by means of conventional booster. For instance, a spacecraft similar to Deep Space-I can be delivered into space by means of a small booster costing less than $ 50 million. The ion engine is expected to provide the tremendous amount of kick needed for Deep Space-Is rendezvous with the asteroid 1992 KD sometime next year. All said and done, the thrust of ion engine is calculated to be 10,000 times weaker than that generated by inter-planetary probes through the exploitation of the slingshot effects of planetary conjunction. The ion engine onboard Deep Space-I is driven by the solar power generated by a pair of solar panels carried by the satellite. Deep Space-Is ion engine is kept in operational trim by means of 82-kg of xenon gas carried onboard. The inert xenon gas is bombarded by electrons that knock away one of the 54 electrons orbiting the nucleus of each atom of xenon. Clearly and apparently, this action results in the positively charged ions. Thereafter, xenon ions are drawn towards the high voltage grids at the open end of engine and spewed into space at a phenomenal speed of 100,000 KPH. This glowing blue stream of xenon gas travelling at a spectacular speed pushes the Deep Space-I towards the asteroid. Even as NASA is keenly
awaiting the performance of the ion propulsion engine
onbaord Deep Space-I probe, ground level tests of space
boosters carrying ion propulsion engines have proved the
feasibility of replacing the chemical fuel driven booster
stages with lightweight, high performance xenon engines.
Space researchers say the availability of ion propulsion
booster could not only help reduce the cost of space
launches but also turn space launches into a routine
affair. |
Why Windows 98 is faster WINDOWS 98 is faster than its predecessor, Windows 95, and offers better memory management integrated Internet Explorer 4.0, excellent multimedia support, better networking environment and lots of more new and enhanced features. But, the question that looms large is How has Windows 98 managed to run the same program faster than its predecessor on the same machine? Microsoft Corp has managed to end the RAM gazzling in Windows 98. Further, it has added certain new features in System Tools folder that make it faster. Nearly 50 per cent reduction in programme load time can be obtained through Windows 98 when used with FAT 32 (File Allocation Table) formatted disk. Here is why Windows 98 memory management works better and why it has some limitations. Windows 95 loads a programme (like AutoCad or Word) by copying its executable file into disk cache memory. In the next step, the operating system copies one or more programme modules in the file to another block of memory, aligning each on a 4 KB page boundary required by virtual memory. After sometime as there is more disk activity, the programmes copy in the cache is discarded and the entire programme is run from the main memory. If you see the memory contents immediately after the application has been launched, youll figure out that there will be two copies of the same programme in it. One copy is in the disk cache and the other one in the memory from where it is being run. It was essential for Windows 95 at that time to use the memory twice the size of a programme itself (though for a very short period). (Illustration 1). In Windows 98 this problem of replica has been eliminated to a certain extent. If a programme code that is already aligned to 4KB boundaries when it is loaded into the cache, Windows 98 will run the code directly from cache. By doing this Windows 98 not only saves extra bit of memory space, but also saves the CPU time, as it will not keep itself busy in moving data to and fro. (Illustration-2) This method surely increases the speed of the programmes but nearly all the code that exist today is unaligned, which means you are not likely to encounter the optimised case until new applications starts to arrive. To help you out with this problem,Microsoft has come up with a utility named Win Align (WINALGN.DLL) that will untomatically align the existing code files. As there are million of softwares available in the market the issue of compatibility exists. So, WinAlign will align only the code that is tested and are known to work once they are aligned. Packages such as Microsoft Office, Adobe Photoshop 5.0, and Front Page 3.0 will work with better speed. List of aligned files could be located in C:|WINDOWS/SYSTEM\ WINALI.INI file. So much for making your system faster. How about making it crash proof? There is a utility in Windows 98, which many users do not know Dr Watson. This utility, which made its debut way back in the Windows 3.x days, remains a mystery for a normal user. However, it is a very important utility for those who know it. It re-emerges stronger than ever in Windows 98. When a serious system-level error occurs. Dr Watson captures information about the state of the system at the time of the error and writes it to a file. This version captures more extensive information, including a list of other programmes running and current hardware configuration. You can use this information to diagnose the problem yourself or you could send it to Microsoft for free technical support over the internet. Windows 98 packs a long list of utilities and software screwdrivers designed to help you help yourself. Lets go through these software screwdrivers, wrenches and other tools that will make your life easy on Windows 98. 1. Automatic Skip Driver Agent: Identifies potentially dangerous failures related to device drivers known to cause Windows 98 system to stop responding; marks them so theyre bypassed on subsequent startups SYSTEM INFORMATION\ TOOLS or WINDOWS\ ASD.EXE. 2. Disk Cleanup: Automates the deletion of unwanted files from your hard disk. 3. FAT Convertor (FAT 32): Optimises your hard drive by converting it to the FAT 32 file system which frees up disk space and boosts programme launch speed. 4. FAT Conversion Information Utility: Estimates the amount of space youd free up if you were to convert your hard disk to FAT 32. I would suggest you download this utility from http://www.microsoft.com or from http://www.download.com. Microsoft is not including this utility with Windows 98 CD-ROM for some particular reason. 5. File Wise: Generates information about files and saves it as tab-delimited text. 6. Link Check Wizard: Scans all icons shortcut files; identifies Dead Links and provides an option for removing them. 7. System Configuration Utility: Lets you troubleshoot system problems, and creates and restores configuration file backups WINDOWS\ SYSTEM\ MSCONFIG.EXE. Note that this file is not visible as an icon on desktop. Youll have to do some traversing before utilising this utility. 8. Windows Registry Checker: This utility will find and resolve registry problems, and regularly backs up the Registry, keeping five backups. This utility is located in WINDOWS directory as SCANREGW.EXE. Note: This file is also not present on the desktop as an icon! 9. Maintenance Wizard: It will manage your system to its optimum speed by scanning the entire disk, defragmenting the files and by removing unwanted files (by using Disk Clean up). 10. Windows Update: Web Site based service that scans your system and offers OS and device driver updates for download and installation. With the utilities mentioned above youll make your system run faster and by using WinAlign will make your system even faster. However, it is always a good practice to read all the necessary information before you utilise any of this tool, particularly if you are a novice Windows user. A lot is said about Windows 98 in the media. However, certain utilities mentioned here were kept untouched for no particular reason. There is a lot of mystery still remaining about Windows 98 and its arsenal of utilities. There are many web sites pertaining to Windows 98 where youll find lots of information. Web sites such as http://www.windows98.rog and http://www.win98-promo.com gives you all the information that youll ever need to run Windows 98 perfectly. On the whole Windows 98
does not give you anything extraordinary over its
predecessor. The utilities mentioned above can also be
loaded onto Windows 95, but Windows 98s improved
performance, memory management diagnostics and
reliability makes it an obvious choice for experienced
Window users. |
Science Quiz 1. A microscope without lenses? Name the Bengali scientist who has developed a "micro microscope" that uses a metal strip with thousands of tiny holes and has a magnification of about 10,000, whereas the maximum magnification produced by an optical microscope is about 450. 2. Different departments and offices can now be linked through satellites, computers and EDI. What is the full form of EDI? 3. These beautiful winter flowers generally grown in home gardens create an illusion of butterflies from a distance. Which flowers are we talking about? 4. Scientists are actively engaged in conducting research about the possible existence of life on objects other than earth. One such well known heavenly body is the planet Mars. Another object under investigation is one of the "moons" of a different planet. Can you name the "moon" and the planet? 5. This beautiful bird is found between heights of 2000 and 4000 metres and its male species resemble a peacock. Name this state bird of Himachal Pradesh characterised by its colourful plumage and its crest which is proudly displayed by people on their caps. 6. Car companies in many countries are in the process of manufacturing special type of vehicles which will help reduce atmospheric pollution to a great extent. What is the general name given to such vehicles? 7. "Uranium series", "Thorium series" and "Actinium series" are the three series of radioactive substances that are found on earth these days. Name the fourth such series that is no longer in existence on earth. 8. The use of greeting cards is increasing in India day by day. Can you imagine how many trees are consumed in the country every year to make greeting cards only? 9. Work at an Indian centre has recently come to an almost standstill due to the introduction of new rules which will badly hit conduct of experiments on animals for developing new drugs, or for other biomedical research throughout the country. Which is this centre and where is it located? 10. The recently released book "India 2020: A vision for the new millenium" outlines plans to make India one of the developed countries of the world. The author of this book was recently conferred with the Indira Gandhi Award for National Integration. Name this leading scientist of India. Answers: 1. Ramenderlal Mukherjee 2. Electronic Data Interchanges 3. Pansy 4. Europa; Jupiter 5. Monal 6. Zero emission vehicles 7. Neptunium series 8. About 15 lakhs 9. National Centre for Laboratory Animal Sciences, Hyderabad 10. Dr. A.P.J. Abdul Kalam.
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