Attenuation of sound in ultrasonic testing.

When sound travels through a medium, it's extreme less with distance. In visual material,  sound pressure (signal amplitude) is only reduced by the spreading of the wave. Natural materials,however, all produce an effect which further weakens the sound. This further weakening results from scattering and absorption. Scattering is the reflection of the sound in directions other than its original direction of propagation. Absorption is the conversion of the sound energy to other forms of energy. The combined effect of scattering and absorption is called attenuation. Ultrasonic attenuation is the decay rate of the wave as it propagates through material. Attenuation of sound with in material itself  is often not essential interest. However, natural properties and loading condition can be related to attenuation. Attenuation often serves as a measurement tool that leads to the formation of theories to explain physical or chemical phenomenon that decreases the ultrasonics intensity. 

BEGINNING OF NON DESTRUCTIVE EVALUATION (NDE).

           Beginnings of nondestructive evaluation:

• Nondestructive testing has been practiced for many decades, with initial rapid developments in instruments in instrumentation spurred by the technological advances that occured during world war2 and the subsequent effort .during the earlier days ,the primary purpose was the detection of defects.As a part of safe life design,it was intended that a structure should not develop macroscopic defect during its life,with the detection of such defect being a cause for removal of the component from service.in response to this need ,increasingly sophisticated techniques using ultrasonic eddy currents,x-rays,dye penetrants,magnetic particles,and other forms of interrogating energy emerged.                                                                                                                                                                          In the early 1970s two event occurredwhich caused the major change in the NDT feild first improvement in the technology led to the ability ti defect small flaws.which caused more parts to be rejected even though the probability of component failure had not change .however the discipline of fracture mechanics emerged which enabledone to predict whether a crack of a given size will fail under a particular load when a materials fracture toughness properties are known other laws were developed to predict the growth rate of crack under cyclic loading with the advent of thes tools it become possible to accept structure containing defect if the sizes of those defects were known This formed the basis for the new philosophy of damage tolerent design component having known defects could continue in service as long as it could be established that those defects would not grow to a critical,failure producing size.
  
        A new challenge was thus presented to the nondestructive testing community.detection was not enough.one needed to also obtain quantitative information about flaw size to serve as an input to fracture mechanics based prediction of remaining life. The need for quantitative information was particularly strongly in the defense and nuclear power industries and led to the emergence of quantitative nondestructive evaluation .as a new engineering research discipline.A number of research programs around the world were started.such as the center for nondestructive evaluation at lowa state university (growing out of a major research effort at the Rockwell international science center): the electric power research institute in charlotte, North carolina; the fraunhofer institute for nondestructive testing in saarbrucken,Germany, and the nondestructive testing center in Harwell,England.                                                                                                                                                 

The History of Book.

        The history of books dates back several thousand years. Here is a brief overview of the development and evolution of books:

1).     Ancient writings: The earliest known form of written information can be traced back to ancient civilizations such as the Sumerians, Egyptians, and Chinese. These civilizations used various materials like clay tablets, papyrus scrolls, and bamboo strips to record texts.

2).       Codex: The codex, an early form of the book as we know it, emerged around the 1st century CE. It consisted of separate pages bound together, replacing the scroll format. The codex allowed for easier navigation and preservation of multiple texts in a single volume.

3).     Manuscripts: During the Middle Ages, books were laboriously copied by hand, mainly by scribes in monastic scriptoria. These handwritten manuscripts were often adorned with intricate illustrations and decorative elements.

4).      Invention of printing press: In the 15th century, Johannes Gutenberg's invention of the printing press revolutionized the production of books. The movable type allowed for faster and more efficient printing. Gutenberg's most famous work, the Gutenberg Bible, was one of the first substantial books printed using the press.

5).      Book production and distribution: With the advent of the printing press, book production increased significantly. The development of commercial printing led to the establishment of printing houses and the rise of publishing as an industry. This, in turn, facilitated the dissemination of knowledge and information to a wider audience.

6).    Paperback books: In the 19th century, advancements in bookbinding techniques led to the production of paperback books. These books were less expensive and more portable, making reading and book ownership more accessible to the masses.

7).     Industrialization and mass production: The Industrial Revolution in the 18th and 19th centuries brought further innovations in book production. Machinery, such as steam-powered presses, improved efficiency and allowed for large-scale production. This led to the growth of publishing companies and a surge in the availability of books.

8).     Digital books: In recent decades, the rise of technology has brought about the digitization of books. E-books, or electronic books, have gained popularity, allowing readers to access texts on electronic devices such as e-readers, tablets, and smartphones. Digital books offer convenience, ease of storage, and the ability to carry an entire library in a single device.

        Today, books continue to be an integral part of our cultural, educational, and entertainment landscapes. They come in various formats, including print, electronic, and audio. The history of books demonstrates how they have evolved and adapted over time to meet the changing needs and preferences of readers.

PRESENT STATE OF ULTRASONICS.

PRESENT STATE OF ULTRASONICS:-Ultrasonic testing (UT) has been practiced for many decades.initial rapid developments in instrumentation spurred by the technological advances from the 1950s continue today. through the 1980s and continuing through the present, computers have provided technicians with smaller and rugged instruments with greater capabilities.Thickness gauging is an example application where instruments have been refined make data collection easier and better.Built in data logging capabilities allow thousand of measurements to be recorded and eliminate the need for a scribe some instruments have the capability to capture waveforms as well as thickness readings.The waveform option allows an operator to view or review the A-scan signal of thickness measurement long after the completion of an inspection. Also some instrument are capable of modifying the measurement based on a surface condition of the material.For example , the signal from a pitted or eroded inner surface of pipe would be treated differently then a smooth surface. This has led to more accurate and repeatable field measurements.

Many ultrasonic flaw detector have a trigonometric function that allows for fast and accurate location determination of flaws when performing shear wave inspections cathode ray tubes,for the most part, have been replaced with LED or LCD screens.These screens, in most cases, are extremely easy to view in a wide range of ambient lighting, Bright or low light working conditions encountered by technician have little effect on the technicians ability to view the screen. screens can be adjusted for brightness,contrast and on some instruments even the color of the screen and signal can be selected.Transducers can be programmed with predetermined instrument settings.The operator only has to connect the transducer and the instrument will set variables such as frequency and probe drive.                                                                                                
Along with computers,motion control and robotic have contributed to the advancement of ultrasonic inspections Early on the advantage of a stationery platform was recognized and used in industry. computers can be programmed to inspect large,complex shaped components, with one or multiple transducers collecting information automated system typically consisted of an immersion tank scanning system and recording system, for a printout of the scan. The immersion tank can be replaced with a squirter systems.which allows the sound to be transmitted through a water column.The resultant C-scan provides a plan or top view of the component.scanning of components is considerably faster than contact hand scanning the coupling is much more consistent.The scan information is collected by a computer for evaluation,transmission to a customer and archiving.

Today,quantitative theories have been developed to describe the interaction of the interrogating fields with flaws.models incorporating the results have been integrated with solid model descriptions of real-part geometries to simulate practical inspections. Related tools allow NDE to be considered during the design process on an equal footing with  other failure-related engineering disciplines.Quantitative description of NDE performance,such as the probability of detection (POD),have become an integral part of statistical risk assessment.measurement procedure initially developed for metals have been extended to engineered materials such as composites,where anisotropy and inhomogeneity have become important issues.The rapid advances in digilization and computing capabilities have totally changed the faces of many instruments and the type of algorithms that are used in processing the resulting data.High-resolution imaging systems and multiple measuerment modalities for characterizing a flaw have emerged.Interest is increasing not only detecting.characterizing,and sizing defects,but also characterizing the materials.Goals range from the determination of fundamental microstructural characteristics such as grain size,porosity and texture (preferred grain orientation),to material properties related to such failure mechanisms as fatigue,creep and fracture toughness.as technology continues to advance,application of ultrasound also advance.The high-resolution imaging systems in the laboratory today will be tools of the technician tomorrow.... 

Future Direction of ultrasonic inspection.

Future Direction of ultrasonic inspection:- Looking to the future those in the field of NDE see an exciting  new set of opportunities.The defense and nuclear power industries have played a major role in the emergence of NDE, increasing global competition has led to dramatic changes in product development and business cycles.At the same time,aging infrastructure,from roads to buildings and aircraft,present a new set of measurement and monitoring challenges for engineers as well as technicians.

Among the new application of NDE spawned by these changes is the increased emphasis on the use of NDE to improve the productivity of manufacturing processes.Quantitative nondestructive evaluation (QNDE) both increases the amount of information about failure modes and the speed with which information can be obtained and facilitates the development of in-line measurements for process control.                                       The phrase,you cannot inspect in quality,you must build it in,exemplifies the industry focus on avoiding the formation of flaws.Nevertheless,manufacturing flaws will never be completely eliminated and material damage will continue to occur in-service so continual development of flaw detection and characterization techniques is necessary.                                                                                                                                                Advanced simulation tools that are designed for inspectability and their integration into quantitative strategies for life management will contribute to increase the number and types of engineering application of NDE.with growth in engineering application for NDE,there will be a need to expand the knowledge base of technicians performing the evaluations.Advanced simulation tools used in the design for inspecatbility may be used to provide technical students with a greater understanding of sound behavior in materials. UTSIM, developed at lowa state university,provides a glimpse into what may be used in the technical classroom as an interactive laboratory tool.    

The History of Ball pen.

The ballpoint pen, commonly known as the ball pen, is a widely used writing instrument that revolutionized the way we write. Here is a brief history of how the ball pen came to be:

1).   Early attempts: The concept of using a ball to deliver ink onto paper dates back to the late 19th century. In 1888, John J. Loud patented a device that used a rotating ball and reservoir to dispense ink. However, Loud's invention never went into mass production.

2).    The Biro brothers: The modern ball pen was invented by Laszlo Biro, a Hungarian-Argentinian journalist, in the late 1930s. Frustrated with the smudging and ink flow issues of fountain pens, Biro sought a solution. He combined a tiny ball bearing with fast-drying ink and created a pen that wrote smoothly on paper.

3).    The first ball pen: In 1943, Biro and his brother, Gyorgy, patented their invention and formed the Biro Pen Company. They started producing ball pens, called Biro pens, which became an instant success due to their reliability and convenience.

4).    Commercialization and improvements: The British Royal Air Force recognized the advantages of the ball pen and ordered large quantities during World War II. The Reynolds International Pen Company in the United States also saw the potential of the ball pen and began manufacturing them in the 1950s.

5).    Further developments: Over the years, various companies and inventors have made improvements to the ball pen. The introduction of tungsten carbide balls in the 1960s increased durability and smoothness. Manufacturers also developed ball pens with different ink types, such as oil-based or gel-based inks, to offer a range of writing experiences.

6).    Fine-tuning and popularity: The ball pen continued to evolve, with advances in ink formulations, ink cartridges, and pen designs. By the late 20th century, ball pens had become the writing instrument of choice for many, surpassing the popularity of fountain pens and pencils.

Today, ball pens are widely used in schools, offices, and everyday life. They offer a reliable and fuss-free writing experience, with a smooth ink flow and the ability to write on various surfaces. The ball pen has truly transformed the way we write, making it easier and more convenient for people around the world.

Which is the best app to book Railway tickets online?

IRCTC Rail Connect App is the reputable app of Indian Railways, through which you can without difficulty book teach tickets, PNR status check, stay train status, uts ticket booking.  However, aside from this app, you will find many apps on Play Store, which supply the facility of booking reserved tickets with the aid of partnering with IRCTC.  Also help passengers to take a look at PNR, check teach between two stations.

RailMitra is one such train app with the assist of which you can check PNR Status of Tickets, Trains between Stations, Live Status of Trains.  Also, with the assist of this Rail App, you can order and enjoy easy and tasty food on the educate 

Disadvantages of mobile phone

Using mobile devices has many advantages, but it also has its disadvantages. Please let us know -

* Mobile phones can cause many diseases in the human body. Electromagnetic radiation from mobile phones can damage DNA. Apart from that, excessive mobile phone use can also lead to many serious illnesses such as mental illness, cancer, brain tumors, diabetes and heart disease.

* Today, most people store confidential information on their mobile phones, which is a mistake. Mobile hackers can exploit this by stealing your secrets and information.

*Keep mobile phones away from your body.

* Radiation from mobile phones can harm the human body.

*In the age of smartphones, children may receive incorrect information due to the influence of the Internet.

* My students' learning and writing skills are very poor because of mobile phones.

* Cell phone use at night weakens people's spirits

*During the inflation period, the amount of waste increased due to mobile phones.

*Limiting cell phone use can reduce the side effects of electromagnetic radiation.

Mobile devices should be used with care, understanding and discretion. Excessive use can cause mental and physical health problems.

How to do Talk Back Off Learn to do Talk Back Off of any cell phone in 2 methods

        How to do Talk Back Off – Friends, on this post, you will understand how you can turn off Talkback on Redmi, Samsung, Oppo, Vivo mobiles by using going to Settings of your mobile and opening Additional Settings and going to Accessibility. Can do.

  

    It is no longer so easy to flip off talkback because when the use of mobile, Voice and Double tab remain on, then contact does not work, cell is speaking, it seems strange, now to flip off talkback, you have to touch the cell with 2 fingers.  Have to use and have to double tab (click) to open any different app or Settings. 

What is Talk Back and who made it

Talkback is given on each Android mobile and when Talkback is grew to become on, many people do now not know how to flip it off, what is the use of talkback, then let's know why the Talkback Feature alternative is given.  The light is weak, talkback has been made for these people who are blind, this characteristic has been made by Google, which is free software, it is regarded as TalkBack.

When the talkback option is on, it tells each notification that comes on the mobile, apart from this, it tells the aspect happening on the display by speaking, due to the fact of this, they are unable to read anything, these people who are unable to see, these people who do now not know how to use mobile, they can without difficulty take help of talkback.  You can run cellular from but many human beings have good understanding of mobile and it is seen that they are not in a position to use mobile.

 Talkback Off Shortcut Key

Talkback choice starts talking as soon as it is on and contact with one finger does not work.  Is.

Step #1.  Talkback Off Press Volume + and Volume – together

We have completed these tricks on Redmi Note 9, first of all, you have to lock your cellular screen or flip on the screen with two fingers, after that, to flip off the talkback option, the volume + and extent – buttons of the mobile have to be pressed together.  The button up and down button have to be pressed for three to 5 seconds after that the talkback will be off. 

How to Talk Back Off

If the talkback alternative of your mobile has no longer been turned off in the above way, then you can flip off the talkback option of your cell by going to “Settings”, in this way you can flip off the talkback option of any different mobile. 

Step #2.  Open cellular settings

1. First of all, you have to turn on the display with the help of two fingers to open the lock or display of your mobile, after that you have to use two fingers to go to the Settings of the mobile, double click on getting the Settings option.  And one factor to remember is that every time you want to open any choice on Settings, you have to double click. 

2. After this, after scrolling up with two fingers, click on Additional Settings.

3. Now click on Accessibility below.

4. After this click on Vision.

5. Then click on TalkBack.

6. Now “Use Talkback” will be on, you can see on the mobile screen, double click on Use TalkBack to turn off this talkback.

7. After this Stop TalkBack page will appear, double click Stop on it.

The History of pencil.

  The history of the pencil is a fascinating journey that spans centuries. Here is a brief overview of the development and evolution of the pencil.

1).    Ancient writing instruments: The origins of the pencil can be traced back to ancient civilizations. The earliest writing instruments consisted of a thin metal or bone stylus that was used to make marks on clay or wax tablets. These early tools were not graphite-based but paved the way for future writing implements.

2).    Discovery of graphite: The discovery of graphite in the Borrowdale region of England in the mid-16th century was a pivotal moment in the history of the pencil. People found that the soft, gray material could be used to make marks on paper, leading to the development of graphite-based writing tools.

3).    Early graphite pencils: In the 17th century, graphite was encased in wooden holders or wrapped in string to create a primitive form of pencils. These early pencils were handmade and lacked the standardized design of modern pencils.

4).   Introduction of the lead pencil: The term "lead pencil" is a misnomer, as pencils do not actually contain lead. However, in the 18th century, a misunderstanding led people to believe that pencils were made with lead cores. The term "lead pencil" stuck, even though the core is made of graphite.

5).   The invention of the modern pencil: The modern pencil, as we know it today, was invented by Nicolas-Jacques Conte in the late 18th century. Conte developed a method for grinding graphite into a fine powder, mixing it with clay to create a uniform consistency, and then baking it in a kiln. This process enabled the creation of high-quality, reliable pencils.

6).    Development of the pencil industry: Throughout the 19th century, the pencil industry grew rapidly. Companies such as Faber-Castell, Staedtler, and Dixon Ticonderoga emerged as pioneers in pencil manufacturing, implementing innovations in production techniques and marketing.

7).    Mechanical pencils: The late 19th century saw the introduction of mechanical pencils, which eliminated the need for sharpening. Mechanical pencils allowed users to extend the lead by pushing a button or twisting the barrel, providing a continuous writing experience.

8).   .Advancements in pencil technology: In recent years, pencils have continued to evolve with innovative designs and materials. Some modern pencils have ergonomic grips for comfort, retractable tips for protection, and even interchangeable lead sizes. Additionally, eco-friendly alternatives made from recycled materials or sustainable sources have gained popularity.

The pencil remains a popular and versatile writing instrument around the world. Its simplicity, ease of use, and ability to create precise marks have made it a staple in schools, offices, and creative endeavors.