MECHANICAL ENGINEERING

flows

BABA — Sun, 10 Nov 2013 18:51:54 GMT

Irrotational vortex

Parallel flow with shear

Yield Criteria for Isotropic Materials

BABA — Sun, 27 Oct 2013 04:14:33 GMT

document files

http://mechanicalengg.ucoz.com/load/yield_criteria_for_isotropic_materials/1-1-0-11

RENDERING OF CLUTCH ASSEMBLY

BABA — Sun, 27 May 2012 05:18:50 GMT

dont forget to leave comments .......................

ur comments are precious to us for further development.

CLUTCH ASSEMBLY

BABA — Wed, 23 May 2012 14:21:47 GMT

CLUTCH ASSEMBLY RENDERED USING CATIA

PARTS ARE PROVIDED IN SITE

Entering the Advanced Meshing Tools Workbench

BABA — Fri, 23 Mar 2012 07:42:30 GMT

Entering the Advanced Meshing Tools Workbench part2

This task shows how to enter in the Advanced Meshing Tools workbench.

Open the Sample01.CATPart document from the sample directory.
Select the Start -> Analysis & Simulation -> Advanced Meshing Tools menu.

You are now in the Advanced Meshing Tools workbench. An Analysis document is
created and the New Analysis Case dialog box is displayed.

2. Select an analysis case type in the New Analysis Case dialog box. In this particular example, select Static Analysis. Optionally, you can activate the Keep as default starting analysis case option if you wish to have Static Analysis Case as default when launching the workbench again.
3. Click OK in the New Analysis Case dialog box.

Defining the Surface Mesh Parameters

1. Click the Advanced Surface Mesher icon .

2. Select the part.
The Global Parameters dialog box appears

3. Define the desired mesh parameters in the Global Parameters dialog box.

In this particular example, you will: select the Set frontal quadrangle method icon as Element shape

in the Mesh tab of the Global Parameters dialog box:
enter 5 mm as Mesh size value n enter 0 mm as Offset value
in the Geometry tab of the Global Parameters dialog box:
enter 1 mm as Constraint sag value n enter 10 mm as Min holes size value n
select the Merge during simplification option n enter 2 mm as Min size

4. Click OK in the Global Parameters dialog box.

A new Advanced Surface Mesh feature is created in the specification tree.

You now enter the Advanced Surface Meshing workshop and the following toolbars are available:

1. Local Specifications
2. Execution
3. Edition Tools
At any time, you can visualize or modify the global parameters. For this, click the Global Parameters icon

The Global Parameters dialog box
appears.

this for today next we start Setting Constraints and Nodes

Advanced Meshing Tools

BABA — Thu, 22 Mar 2012 09:52:44 GMT

Advanced Meshing Tools PART 1

Advanced Meshing Tools allows you to rapidly generate a finite element model for
complex parts whether they are surface or solid.In other words, you will generate associative meshing from complex parts, with advanced control on mesh specifications.The Advanced Meshing Tools workbench is composed of the following products:
1 FEM Surface (FMS): to generate a finite element model for complex surface parts.
2 FEM Solid (FMD): to generate a finite element model for complex solid parts.
The main tasks proposed in this section are:

Entering the Advanced Meshing Tools Workbench
Defining the Surface Mesh Parameters
Setting Constraints and Nodes
Launching the Mesh Operation
Analyzing Element Quality
Mesh Editing
Re-meshing a Domain

ENTERING THE ADVANCE MESHING IS OUR

NEXT TOPIC.........................TO BE CONTD.

backtrack-5 FORENSIC guide

BABA — Wed, 14 Mar 2012 18:07:23 GMT

Backtrack 5 Forensics

1. Anti Virus Forensic Tools
◦ chkrootkit
◦ rkhunter
2. Digital Anti Forensics
◦ Install truecrypt
◦ Digital Forensics
◦ hexedit
4. Forensic Analysis Tools
◦ bulk_extractor
◦ evtparse
◦ exiftool
◦ missidentify
◦ mork
◦ pref
◦ PTK
◦ readpst
◦ reglookup
◦ stegdetect
◦ vinetto
5. Forensic Carving Tools
◦ fatback
◦ foremost
◦ magicrescue
◦ recoverjpeg
◦ safecopy
◦ scalpel
◦ scrounge-ntfs
◦ testdisk
6. Forensic Hashing Tools
◦ hashdeep
◦ md5deep
◦ sha1deep
◦ sha256deep
◦ tigerdeep
◦ whirlpooldeep
7. Forensic Imaging Tools
◦ air
◦ dc3dd
◦ ddrescue
◦ ewfaquire
8. Forensic Suites
◦ PTK
◦ Setup Autopsy
◦ Sleuthkit
9. Network Forensics
◦ Driftnet
◦ p0f
◦ tcpreplay
◦ Wireshark
◦ Xplico
10. Password Forensics Tools
◦ CmosPwd
◦ fcrackzip
◦ samdump
11. PDF Forensic Tools
◦ pdfid
◦ pdf-parser
◦ peepdf
12. RAM Forensics Tools
◦ pdfbook
◦ pdgmail
◦ PTK
◦ Volatility
Anti Virus Forensic Tools

chkroot

Example usage: chkrootkit -p [path-to-trusted-binaries] -r [root-path-to-scan]
rkhunter
rkhunter is another utility used to check for signs of rootkits on Unix based systems. Usually, you
will want to run the scan against a mounted filesystem, using a trusted set of binaries. In the below
Example Usage: rkhunter -c –sk

Digital Anti Forensics

Install truecrypt
This script is used to install Truecrypt, software that is used to create encrypted files using various
encryption ciphers. It contains features such as hidden partitions inside the encyption file, as well

as the ability to use files and text passwords as keys to the encryption file.
Digital Forensics
hexedit
hexedit is a program that gives the user the ability to view a file in hexadecimal and ASCII view.
It offers the ability to read a device as a file. It includes build in key shortcuts to make it fast and easy to edit and analyze file, including skipping to specific memory locations, cutting and pasting,
changing views, modes, and syntaxes similar to that of emacs.
Example usage: hexedit [filename]

Forensic Carving Tools

fatback
Fatback is a tool which is used to recover deleted files from FAT filesystems. Fatback will read an image of a FAT filesystem, and then outputs all deleted files into a directory determined by the user. This is useful in investigations with Windows machines, since many older Windows installs utilize some form of a FAT filesystem (FAT16, FAT32). Many USB flash drives currently employ some form of a FAT filesystem. The example below takes a FAT filesystem image, outputs the log created by fatback to a directory determined by the user, writes verbosely to the terminal screen, outputs deleted files to a directory determined by the user, and automatically recovers all
files the have been deleted.
Example usage: fatback [image] -l [logfile to output] -v -o [output directory] -a
foremost
Foremost is a well known utility that specializes in file carving. It takes image files, such as those created by dd, and will search for file headers in order to recover files. It returns information to the user by outputting files found to a predetermined directory set by the user. The example below outputs JPEG images found in image.img (an image file created by dd) and outputs everything
found in /root/Desktop/output/.
Example usage: foremost -v -t jpeg -o /root/Desktop/output/ -i image.img
magicrescue
Magic Rescue is a program that searches a filesystem image for "magic number" bytes, and attempts to recover the files that these magic numbers belong to. Magic numbers are basically several bytes of data that act as a file identifier, giving basic information such as file type. The below example usage uses the jpeg-jfif "recipe" (others are found
in /usr/local/share/magicrescue/recipes), meaning it looks for JPEG files based on the JFIF header.The output directory is /root/Desktop/output/, and the image being analyzed in /dev/sdb1, although it can be any filesystem or image file.
Example usage: magicrescue -r jpeg-jfif -d /root/Desktop/output/ /dev/sdb1
recoverjpeg
RecoverJPEG is another utility to recover JPEG images from a filesystem. RecoverJPEG can take input either as a partition (like /dev/sda1) or an image file, like those produced by dd. The below example will recover JPEG images found in the image.img file.
Example usage: recoverjpeg image.img
safecopy
Safecopy is a program used to recover as much data as possible from a damaged device, such as a hard drive or USB drive. Unlike other programs such as dd, cat, or cp, safecopy specializes in damaged devices. Other programs will stop reading data once a damaged area is hit, while Safecopy will read to a point designated by the user, regardless of damaged areas. It does this by identifying the damaged areas, and skipping around them. This example shows how to use Safecopy to recover data on /dev/sdb1, a mounted device that other programs such as cp or dd fail on. It outputs data recovered to /root/Desktop/rescued_files:
Example usage: safecopy /dev/sdb1 /root/Desktop/rescued_files
scalpel
Scalpel is a well known file carving utility that searches a database of known file header and footer signatures, and attempts to carve files from a disk image file. To begin using Scalpel, the scalpel.conf file needs to edited to tell Scalpel which filetypes you are looking for. Example
This example uses a configuration file named scalpel.conf, searches the disk image file
image.img, and outputs all files carved to /root/Desktop/scalpel_results/
Example usage: scalpel -c scalpel.conf image.img -o /root/Desktop/scalpel_results/
scrounge-ntfs
Scrounge-NTFS is a utility that can be used to recover information from an NTFS partition.Scrounge-NTFS will use information provided by the user in order to rebuild the filesystem tree,which is places on another partition. This program requires you to know the start and end block of the filesystem, but it provides a page to help you guess partition information. The example below
uses a cluster size of 8 (the most common, always multiples of 2), sets the output directory
to /root/Desktop/output/, reads data from /dev/sda1, starts at sector 63 and ends at sector
81920000, meaning the overall disk has around 40 GB of space.
Example usage: scrounge -c 8 -o /root/Desktop/output/ /dev/sdb1 63 81920000
testdisk
TestDisk is a program that specializes in recovering lost disk partitions, and making disks
bootable. It has the ability to rebuild partition tables, rebuild boot sectors, fix the Master File
Table (MFT), recover files, and more. The program contains many features, so rather than post a small example usage here, I would suggest looking at their very thorough Step by Step Guide.

OVERCLOACKING MICROPROCESSORS

BABA — Fri, 04 Nov 2011 11:54:49 GMT

hi,deamon is back again with a ,thing new imgine what..........

OVERCLOACKING OF MICROPROCESSOR.

LET US START FROM VERY BASIC..........

What is a processor and what does it do?
The processor (often called the CPU) is the brain of your PC and is where the majority of the work is performed.
As its name suggests a processor processes something, that something is data, this data is made up of 0's and 1's (zeroes and ones).
To understand a processor we first need to take a quick look at the way digital systems function. All of the work that goes on inside your PC is carried out by the means of voltage, or more accurately the difference in two voltages.Digital systems use only two voltages, one which is a low voltage (usually between 0 and 1 volt) and one which is a high voltage (typically between 3 and 5 volts). These low and high voltages represent off and on respectively, a digital system will interpret these off and on states as 0 and 1. In other words if the voltage is low then it would represent 0 (off state), and if the voltage is high then it would represent a 1 (on state).
These zeroes and ones are called bits. The word bit is short for Binary Digit.
For example here are 8 bits (binary digits): 10010010

Processor Architecture

A processor (as stated earlier) processes bits (binary digits) of data. In its simplest form, the processor will retrieve some data, perform some process on that data, and then store the result in either its own internal memory (cache) or the systems memory.
You may have seen processors advertised as 32-bit or 64-bit, this basically means that the processor can process internally either 32 bits or 64 bits of data at any one time.
This would theoretically make a 64-bit processor twice as fast as its 32-bit counterpart.
Software can also be defined as either 16-bit, 32-bit or 64-bit. You can probably see that theoretically, if you are using 64-bit software with a 32-bit processor then it would take two clock cycles (32-bits at a time) to process any one set of 64-bits, this is referred to as a bottleneck.
Processor Clock Speed

Every processor has its own built-in clock, this clock dictates how fast the processor can process the data (0's and 1's). You will see processors advertised as having a speed of say 2GHz, this measurement refers to the internal clock.
If a processor is advertised as having a speed of 2GHz, this means that it can process data internally 2 billion times a second (every clock cycle). If the processor is a 32-bit processor running at 2GHz then it can potentially process 32 bits of data simultaneously, 2 billion times a second !!
Front Side Bus (FSB)

Overall processor performance relies on other internal and external factors, one of which is the processor's front side bus (FSB) speed, two common figures for the Intel Pentium 4 are 533MHz and 800MHz.
The front side bus consists of two channels, one for transferring data, and one for indicating the memory address where the data is to be retrieved from or stored.
The front side bus transfers data between the processor and the computer's other components such as memory, hard drives, etc. The FSB will have a certain width (measured in bits) which dictates how many bits can be transferred at any one time. As the 533MHz and 800MHz figures suggest, the FSB also has a clock cycle frequency indicating how fast the data can be transferred.
For example a processor having a FSB width of 32-bits and running at 533MHz, can transfer a set of 32-bits of data, 533,000,000 times a second.
Instruction Sets

The type of work a processor carries out is defined by its instructions, these instructions are coded in binary. All modern processors have their own instructions built-in for common tasks.
Having these instruction sets built-in allow the processor to carry out certain operations much faster. The instruction sets that are built-in depend on the processor's architecture, there are two main types of processor architecture on the market, CISC and RISC.

CISC (Complex Instruction Set Computer)

CISC processors have more internal instructions than its RISC counterpart allowing a more diverse set of operations. Although this may sound the best option, CISC processors are generally slower due to the complexity of the instructions. Some people think the benefit of having more complex instructions built-in outweigh the performance lose, but it would depend on the applications that the processor is going to run.

RISC (Reduced Instruction Set Computer)

RISC processors, as the name suggests, have fewer built-in instructions, this can add to the overall speed of the processor due to the simplicity of the instructions, but again the performance would depend on the type of applications the processor was to be used for.
Most modern processors have built-in instructions specifically designed for certain applications such as 3D graphics, audio manipulation, etc. One example of this would be the MMX (MultiMedia eXtension) technology which Intel built-in to its Pentium architecture in the late nineties. This was a special set of internal instructions that allowed the faster processing of audio and visual algorithms.

Cache (L2)

L2 Cache (pronounced cash) is a special block of memory inside the processor (in the same chip) which offers faster data retrieval, typical sizes are 128KB, 256KB and 512KB.
note: Some processors (generally older) utilise external L2 cache.
The data that the processor stores in its cache memory will be data that is frequently used (such as a certain algorithm), the processor will also guess what data may be required and store this data in its cache. This guessing may be successful or it may not, the success rate is known as a hit rate. For instance, if the hit rate was 94% then it would mean that 94 out of every 100 attempts the processor correctly identified and stored a block of data which was needed, the other 6 times the data was never used.

Arithmetic Logic Unit (ALU)

The ALU is an internal part of the processor which is used for all mathematical and logical operations. The basic operations of an ALU include adding and multiplying binary values, as well as performing logical operations such as AND, OR and XOR. The algorithms for performing these mathematical and logical operations are hard coded (stored permanently) within the ALU.

Floating Point Unit (FPU)

The FPU is also an internal part of modern processors. The FPU is designed to handle any floating point calculations, and like the ALU it has its algorithms hard coded (stored permanently) inside the unit.
With the Intel family of processors up until the 80486DX the floating point unit was an external unit (commonly called a math coprocessor), subsequent processors such as the Pentium have the FPU built in. For example, if you had the (now old) 80386SX processor from Intel you would be able to purchase the 80387 coprocessor, which was in fact the floating point unit.

PLASMA STEALTH USED BY RUSSIANS

BABA — Thu, 09 Jun 2011 14:54:23 GMT

Plasma stealth

is a proposed process to use ionized gas (plasma) to reduce the radar cross section (RCS) of an aircraft. Interactions between electromagnetic radiation and ionized gas have been extensively studied for many purposes, including concealing aircraft from radar as stealth technology. Various methods might plausibly be able to form a layer or cloud of plasma around a vehicle to deflect or absorb radar, from simpler electrostatic or radio frequency (RF) discharges to more complex laser discharges.It is theoretically possible to reduce RCS in this way, but it may be very difficult to do so in practice.

First claims

In 1956, Arnold Eldredge, of General Electric, filed a patent application for an "Object Camouflage Method and Apparatus," which proposed using a particle accelerator in an aircraft to create a cloud of ionization that would "...refract or absorb incident radar beams." It is unclear who funded this work or whether it was prototyped and tested. U.S. Patent 3,127,608 was granted in 1964.

During Project OXCART, the operation of the Lockheed A-12 reconnaissance aircraft, the CIA funded an attempt to reduce the RCS of the A-12's inlets. Known as Project KEMPSTER, this used an electron beam generator to create a cloud of ionization in front of each inlet. The system was flight tested but was never deployed on operational A-12s or SR-71s.

Despite the apparent technical difficulty of designing a plasma stealth device for combat aircraft, there are claims that a system was offered for export by Russia in 1999. In January 1999, the Russian ITAR-TASS news agency published an interview with Doctor Anatoliy Koroteyev, the director of the Keldysh Research Center (FKA Scientific Research Institute for Thermal Processes), who talked about the plasma stealth device developed by his organization. The claim was particularly interesting in light of the solid scientific reputation of Dr. Koroteyev and the Institute for Thermal Processes, which is one of the top scientific research organizations in the world in the field of fundamental physics.

The Journal of Electronic Defense reported that "plasma-cloud-generation technology for stealth applications" developed in Russia reduces an aircraft's RCS by a factor of 100. According to this June 2002 article, the Russian plasma stealth device has been tested aboard a Sukhoi Su-27IB fighter-bomber. The Journal also reported that similar research into applications of plasma for RCS reduction is being carried out by Accurate Automation Corporation (Chattanooga, Tennessee) and Old Dominion University (Norfolk, Virginia) in the U.S.; and by Dassault Aviation (Saint-Cloud, France) and Thales (Paris, France).

Plasma and its properties

A plasma is a quasineutral (total electrical charge is close to zero) mix of ions (atoms which have been ionized, and therefore possess a net charge), electrons, and neutral particles (possibly including un-ionized atoms). Not all plasmas are fully ionized. Almost all the matter in the universe is plasma: solids, liquids and gases are uncommon away from planetary bodies. Plasmas have many technological applications, from fluorescent lighting to plasma processing for semiconductor manufacture.

Plasmas can interact strongly with electromagnetic radiation: this is why plasmas might plausibly be used to modify an object's radar signature. Interaction between plasma and electromagnetic radiation is strongly dependent on the physical properties and parameters of the plasma, most notably, the temperature and density of the plasma. Plasmas can have a wide range of values in both temperature and density; plasma temperatures range from close to absolute zero and to well beyond 10⁹ kelvins (for comparison, tungsten melts at 3700 kelvins), and plasma may contain less than one particle per cubic metre, or be denser than lead. For a wide range of parameters and frequencies, plasma is electrically conductive, and its response to low-frequency electromagnetic waves is similar to that of a metal: a plasma simply reflects incident low-frequency radiation. The use of plasmas to control the reflected electromagnetic radiation from an object (Plasma stealth) is feasible at higher frequency where the conductivity of the plasma allows it to interact strongly with the incoming radio wave, but the wave can be absorbed and converted into thermal energy rather than reflected.

Plasmas support a wide range of waves, but for unmagnetised plasmas, the most relevant are the Langmuir waves, corresponding to a dynamic compression of the electrons. For magnetised plasmas, many different wave modes can be excited which might interact with radiation at radar frequencies.

Plasmas on aerodynamic surfaces

Plasma layers around aircraft have been considered for purposes other than stealth. There are many research papers on the use of plasma to reduce aerodynamic drag. In particular, electrohydrodynamic coupling can be used to accelerate air flow near an aerodynamic surface. One paperconsiders the use of a plasma panel for boundary layer control on a wing in a low-speed wind tunnel. This demonstrates that it is possible to produce a plasma on the skin of an aircraft. Xenon nuclear poison isotopes when successfully suspended in the plasma layers or vehicle hull can be utilized to reduce radar cross-section and will shield against HMP/EMP and HERF weaponry.

Absorption of EM radiation

When electromagnetic waves, such as radar signals, propagate into a conductive plasma, ions and electrons are displaced as a result of the time varying electric and magnetic fields. The wave field gives energy to the particles. The particles generally return some fraction of the energy they have gained to the wave, but some energy may be permanently absorbed as heat by processes like scattering or resonant acceleration, or transferred into other wave types by mode conversion or nonlinear effects.

A plasma can, at least in principle, absorb all the energy in an incoming wave, and this is the key to plasma stealth. However, plasma stealth implies a substantial reduction of an aircraft's RCS, making it more difficult (but not necessarily impossible) to detect. The mere fact of detection of an aircraft by a radar does not guarantee an accurate targeting solution needed to intercept the aircraft or to engage it with missiles. A reduction in RCS also results in a proportional reduction in detection range, allowing an aircraft to get closer to the radar before being detected.

The central issue here is frequency of the incoming signal. A plasma will simply reflect radio waves below a certain frequency (which depends on the plasma properties). This aids long-range communications, because low-frequency radio signals bounce between the Earth and the ionosphere and may therefore travel long distances. Early-warning over-the-horizon radars utilize such low-frequency radio waves. Most military airborne and air defense radars, however, operate in the microwave band, where many plasmas, including the ionosphere, absorb or transmit the radiation (the use of microwave communication between the ground and communication satellites demonstrates that at least some frequencies can penetrate the ionosphere).

Plasma surrounding an aircraft might be able to absorb incoming radiation, and therefore prevent any signal reflection from the metal parts of the aircraft: the aircraft would then be effectively invisible to radar. A plasma might also be used to modify the reflected waves to confuse the opponent's radar system: for example, frequency-shifting the reflected radiation would frustrate Doppler filtering and might make the reflected radiation more difficult to distinguish from noise.

Control of plasma properties is likely to be important for a functioning plasma stealth device, and it may be necessary to dynamically adjust the plasma density, temperature or composition, or the magnetic field, in order to effectively defeat different types of radar systems. Radars which can flexibly change transmission frequencies might be less susceptible to defeat by plasma stealth technology. Like LO geometry and radar absorbent materials, plasma stealth technology is probably not a panacea against radar.

Plasma stealth technology also faces various technical problems. For example, the plasma itself emits EM radiation. Also, it takes some time for plasma to be re-absorbed by the atmosphere and a trail of ionized air would be created behind the moving aircraft. Thirdly, plasmas (like glow discharges or fluorescent lights) tend to emit a visible glow: this is not necessarily compatible with overall low observability. Furthermore, it is likely to be difficult to produce a radar-absorbent plasma around an entire aircraft traveling at high speed. However, a substantial reduction of an aircraft's RCS may be achieved by generating radar-absorbent plasma around the most reflective surfaces of the aircraft, such as the turbojet engine fan blades, engine air intakes, and vertical stabilizers.

At least one detailed computational study exists of plasma-based radar cross section reduction using three-dimensional computations.

RADAR ABSORBING MATERIAL

BABA — Thu, 09 Jun 2011 11:19:30 GMT

NEW RADAR ABSORBING MATERIAL
FOR STEALTH AIRCRAFTS

(RAM), often as paints, are used especially on the edges of metal surfaces. While the material and thickness of RAM coatings is classified, the material seeks to absorb radiated energy from a ground or air based radar station into the coating and convert it to heat rather than reflect it back.