CHAT GPT क्या है।

CHAT GPT क्या है।

CHAT GPT (Chat-based GPT) एक भाषा विधान प्रतिमान है जिसे OpenAI ने विकसित किया है। यह एक नाटकीय प्रतिष्ठान है जो मतदान और उपयोगकर्ता के प्रश्नों का उत्तर देने के लिए बनाया गया है। यह सामान्य संवाद बनाने, विचार-विमर्श करने और जानकारी प्राप्त करने के लिए प्रयोग किया जाता है।

CHAT GPT को विकसित करने के लिए, OpenAI ने बड़ी मात्रा में डेटा का उपयोग किया है जिसमें अनलाइन संवादों, ब्लॉग पोस्ट, न्यूज़लेटर आदि शामिल हैं। यह प्रतिष्ठान एक गहन आंतरिक परीक्षा के बाद एक सार्वजनिक बीटा संस्करण जारी करने का निर्णय लिया है, जिसे ईंधन के रूप में उपयोगकर्ताओं को उपलब्ध कराया जा सकेगा।

CHAT GPT एक AI प्रणाली है जो शैली, भाषा और सामग्री के अनुसार बदल सकती है। यह उपयोगकर्ता के प्रश्नों को समझती है और उनके ऊपर उचित उत्तर प्रदान करती है। इसका उपयोग टेक्स्ट एडिटिंग, सामग्री सारणीकरण, अनुरोध प्रबंधन और और भी कई कार्यों के लिए किया जा सकता है। इसका उपयोग इंटरनेट सदस्यता, संपर्क फॉर्म उत्तर, वाणिज्यिक उपयोगकर्ता सपोर्ट, गेमिंग आदि में किया जा सकता है।

Magnetic field orientation and flaw detectable.

Magnetic field orientation and flaw detectable. 

The type of magnetic field established is determined by the method used to magnetize the specimen. Being able to magnetize the part in two direction is important because the best detection of defects occurs when the lines of magnetic force are established at right angles to the longest dimensions of the defect. This orientation creates the largest disruption of the magnetic field within the part and the greatest flux leakage at the surface of the part. As can be seen in the image, if the magnetic field is parallel to the defect, the field will see little disruption and no flux leakage field will be produced.

An orientation of 45 to 90 degrees between the magnetic field and the defect is necessary to form an indication. Since defects may occur in various and unknown directions, each part is normally magnetized in two directions at right angles to each other. If the component below is considered, it is known that passing current through the part from end to end will establish a circular magnetic field that will be 90degrees to the direction of the current. Therefore, defects that have a significant dimension in the direction of the current (longitudinal defects)  should be detectable. Alternately, transverse -type defects will not be detectable with circular magnetization. 

THE HYSTERESIS LOOP AND MAGNETIC PROPERTIES.

THE HYSTERESIS LOOP AND MAGNETIC PROPERTIES. 

A great deal of information can be learned about the magnetic properties of a materials by studying it's hysteresis loop. A hysteresis loop shows the relationship between the induced magnetic flux density (B) and the magnetizing force (H). It is often referred to as the B-H loop.
The loop is generated by measuring the magnetic flux of a ferromagnetic material while the magnetizing force is changed. A ferromagnetic material that has never been previously magnetized or has been throughly demagnetized will follow the dashed line as H is increased. As the line demonstrates the greater the amount of current applied (H+), the stronger the magnetic field in the component ((B+). At point  "a" almost all of the magnetic Domains are aligned andante additional increase in the magnetizing force will produce very little increase in magnetic flux. The material has reached the point of magnetic saturation. When H is reduced to zero, the curve will move from point "a" to point "b" At this point, it can ne seen that some magnetic flux remains in the material even though the magnetizing force is zero. This is referred to as the point of retentive on the graph and indicates the remanence or level of residual magnetism in the material. (Some of the magnetic domains remain aligned but some have lost their alignment)  As the magnetizing force is reversed, the curve moves to point "c" where the flux has been reduced zero.This is Allen the point of coercivity on the curve.( The revised magnetizing force has flipped enough of the domains so that the net flux within the material is zero.)  The force required to remove the residual magnetism from the material is called the coercive force or coercivity of the material. 

MAGNETIZATION USING DIRECT INDUCTION.

MAGNETIZATION USING DIRECT INDUCTION. 

With direct magnetization, current passed directly through the component. Recall that whenever current flows, a magnetic field is produced. Using the right-hand rule, which was introduced earlier, it is known that the magnetic lines of flux form normal to the direction of the current and form a circular field in and around the conductor. When using the direct magnetization method, care must be taken to ensure that good electrical contact is established and maintained between the test equipment and the test component improper contact can result in arcing that may damage the component. It is also possible to overheat component in areas of high resistance such as the contact points and in areas of small cross - sectional area.

  There are several ways that direct magnetization is commonlyaccomplished. One way involves clamping the component between two electrical contacts in a special piece of equipment. Current is passed through the component and a circular magnetic field is established in and around the component.
  When the magnetizing current is stopped, a residual magnetic field will remain within the component. The strength of the induced magnetic field if proportional to the amount of current passed through the component.

What is wave propagation in ultrasonic testing.

What is wave propagation in ultrasonic testing. 

Ultrasonic testing is based on time-varying deformation or vibrations in materials, which is generally refered to as accustics.All material substances are comprised atoms,which may be forced into vibrational motion about their equilibrium positions.

 Many different patterns of vibrational motion exist at the atomic level,however,most are irrelevant to acoustics and ultrasonic testing.Acoustics is focused on particles that contain many atoms that move in unison to produce a mechanical wave.when a material is not stressed in tension or compression beyond its elastic limit.its individual particles perform elastic oscillation.When the particles of a medium are displaced from their equilibrium position, internal(electrostatic)restoration forces arise.It is these elastic restoring forces between particles,combined with inertia of the particles, that lead to the oscillatory mation of the medium.In solids, sound waves can propagate in four principle modes that are based on the way the particles oscillate.Sound can propagate as longitudinal waves, shear waves, surface waves,and in thin material as plate waves.Longitudinal and shear waves are the two modes of propagation most widely used in ultrasonic testing. The particle movement responsible for the propagation of longitudinal and shear waves is illustrated below.                                                      

      In longitudinal waves,the oscillations occur in the longitudinal direction or the direction of wave propagation since compressional and dilational forces are active in these waves, they are also called pressure or compressional waves.They are also sometimes called density waves because their particle density fluctuates as they move.compression waves can be generated in liquids,as well as solids because the energy travels through the atomic structure by a sereies of comparison and expansion (rarefaction) movements.

MAGNETIZATION USING INDIRECT INDUCTION.

MAGNETIZATION USING INDIRECT INDUCTION. 

Indirect magnetization is accomplished by using a strong external magnetic field to establish a magnetic field within the component. As with direct magnetization, there are several ways that indirect magnetization can be accomplished.
The use of permanent magnets is a low cost method of establishing field. However, their use is limited due to lack of control of the field strength and the difficulty of placing and removing strong permanent magnets from the component.
Electromagnetes in the form of an adjustable horseshoe magnet ( called a yoke) eliminate the problems associated with permanent magnets and are used extensively in industry. Electromagnetes only exhibit a magnetic flux when electric current is flowing around the soft iron core. When the magnet is placed on the component, a magnetic field is established between the north and south poles of the magnet.
Another way of indirectly inducing a magnetic field in a material is using the magnetic field of a current carrying conductor. A circular magnetic field can be established in cylindrical components by using a central conductor.  Typically, one or more cylindrical component are hung from a solid copper bar running through the inside diameter. current is passed through the copper bar and the resulting circular magnetic field establishes a magnetic field within the test components.

MAGNETIZING CURRENT IN MAGNETIC PARTICLE INSPECTION.

MAGNETIZING CURRENT IN MAGNETIC PARTICLE INSPECTION. 

Half wave Alternative current (HWAC):-

When single phase alternative current is passed through a rectifier, current is allowed to flow in only one direction. The reverse half of each cycle is blocked outsourcing that a one directional, pulsating current is produced. The current rises from zero to a maximum and then returns to zero. No current flows during the time when the reverse cycle is blocked out. The HAWC repeat at same rate as the unrectified current (60hertz typical). Since half of the current is blocked out, the amperage is halftone the unaltered AC.
This type of current is often referred to as half wave Dc or pulsating DC. The pulsation of the HWAC helps magnetic particle inspection form by vibrating the particles and giving them added mobility. This added mobility is especially important when using dry particles. The pulsation is reported to significantly improve inspection sensitivity. HAWC IS most often used to power Electromagnetic yokes.

Full Wave Rectified Alternating Current (FWAC):-

Full wave rectification inverts the negative current to positive current rather than blocking it out. This produces a pulsating DC with no interval between the pulses. Filtering is usually performed to soften the sharp polarity switching in the rectified current. While particle mobility is not as good as half - wave AC due to the reduction in pulsation, the depth of the subsurface magnetic field is improved.

Three Phase Full Wave Rectified Alternating Current :- 

Three phase current is often used to power industrial equipment because it has more favorable power transmission and line loading characteristics. These type of electrical current is also highly desirable for magnetic particle testing because when it is rectified and filtered, the resulting current very closely resembles direct current. 

Longitudinal Magnetic Fields in Magnetic Particle Inspection.

Longitudinal Magnetic Fields in Magnetic Particle Inspection. 

When the length of a component is several times larger than its diameter, a longitudinal Magnetic field can be established in the component. The component is often placed longitudinally in the concentrated magnetic field that fills the center of a coil or solenoid. This magnetization technique is often referred to as a coil shot.
The magnetic field travels through the component from end to end with some flux loss along its length as shown in the image to the right. keep in mind that the magnetic lines of flux occur in three dimensions and are only shown in 2D in the image. The magnetic lines of flux are much denser inside the ferromagnetic material than in air because ferromagnetic materials have much higher permeability than does air. When the concentrated flux within the material comes to the air at the end of the component, it must spread out since the air can not support as many lines of flux per unit volume. To keep from crossing as they spread out, some of the magnetic lines of flux are forced out the side of the component. 

magnatic particle test.

When a component is magnetized along its complete length, the flux loss is small alongside length. Therefore, when a component is uniform in cross section and magnetic permeability, the flux density wellbeing relatively uniform throughout the component. Flaws that run normal to the magnetic lines of flux will disturb the flux lines and often cause a leakage field at the surface of the component.

When a component with considerable length is magnetized using a solenoid, it is possible to magnetize only a portion of the component. Only the material within the solenoid and about the same width on side of the solenoid will be strongly magnetized. At some distance from the solenoid, the magnetic lines of force will abandon their longitudinal direction, leave the part at a pole on one side of the solenoid and return to the part at a opposite pole on the other side of the solenoid. This occurs because the magnetizing force diminishes with increasing distance from the solenoid. As a result, the magnetizing force may only be strong enough to align the magnetic domains within and very near the solenoid. The unmagnetized portion of the component will not support as much magnetic flux as the magnetized portion and some of the flux will be forced out of the part as illustrated in the image below. Therefore a long component must be magnetized and inspected at several location along its length for complete inspection coverage. 

Circular Magnetic Field Distribution and Intensity.

As discussed previously, when current is passed through a solid conductor, a magnetic field forms in and around the conductor. The following statements can be made about the distribution and Intensity of the magnetic field.
1)    The field strength varies from zero at the centre of the component to a maximum at the surface.
2)    The field strength at the surface of the conductor decreases as the radius of the conductor increases when the current strength is held constant.( However, a larger conductor is capable of carrying more current.)
3)    The field strength outside the conductor is directly proportional to the current strength. Inside the conductor, the field strength is dependent on the current strength, magnetic permeability of the material, and if magnetic, the location on the B-H curve.
4)    The field strength outside the conductor decreases with distance from the conductor.
In the images below, the magnetic field strength is graphed versus distance from the centre of the conductor. It can be seen that in a nonmagnetic carrying DC, the internal field strength rises from zero at the centre to a maximum value at the surface of the conductor. The external field strength decreases with distance from the surface of the conductor. When the conductor is a magnetic material, the field strength within the conductor is much greater than it was in the nonmagnetic conductor. This is due to permeability of the magnetic material. The external field is exactly the same for the two materials provided the current level and conductor radius are the same.