Previously we're talking about Nikola Tesla's early life. But except for his inventions, it's not possible for us to know his diligence and dedication. Here we'll try to highlight some of his phenomenal inventions.

01-Alternating System

If you think that the alternating current (AC) was invented by Tesla, you need to recheck it. AC was invented long ago Tesla started his works. So what did Tesla do??? Tesla, through his phenomenal inventions, set the standard of AC in the whole world and he also designed the transmission and generation of AC. But what triggered him to go for AC while the contemporary world was fascinated with Thomas Edison's DC? Have you heard of the famous incident, "War of Currents"?

02-Induction Motor

Induction Coil of Tesla

While studying electrical engineering at the Polytechnic Institute at Graz in Austria, he could perceive the design flaws in the DC motors being demonstrated there. Later he spent 6 years of his life thinking of electromagnetic fields and a hypothetical motor that would run on AC. After his vision about this motor and upon getting investors, he could finally build the AC motor namely Induction motor. And it worked exactly as Tesla had thought. Believe it or not, he had drawn the design of the motor in the sand as he got the vision in a park!

03-Tesla Coil

The Magnifying Transmitter

Tesla was inspired by Heinrich Hertz's experiment, which proved the existence of electromagnetic radiation including radio waves. But operation above 20KHz (Radio Wave) was unknown. Tesla dived deeper into it and he made an electrical resonant transformer circuit that could produce very high voltage with high frequency and low current. He also applied his idea of  tesla coil in the wireless power transmission project.

04-Polyphase System

Tesla used the theme of the polyphase system in his Induction motor. Later on, his generation and powerplant system also applied the polyphase scheme as it is more economical. Tesla holds patents on the polyphase system.

05-X-Ray Experiment

X-ray of Roentgent's wife hand

As we all know Wilhelm Roentgen as the inventor of X-rays. And the Roentgen's X-ray film of his wife is evident with her wedding ring on her finger. But it is assumed that Tesla had captured X-ray images accidentally while working with tubes in his previous experiments before the declaration came from Roentgen. After hearing Roentgen's invention, Tesla proceeded with his own experimentations of X-rays. His discovered instrument had his own designed vacuum tube with a single terminal. That means, unlike Roentgent, it contained no target electrode and it could produce high energy. A tesla coil's output was used in this experiment. 

 X-ray of Tesla's hand

06-Remote Control

    Radio Controlled Boat

It became an unbelievable incident to people when Tesla experimented with his "Teleautomaton" during an electrical exhibition at Madison Square Garden. He built a boat and controlled its motion & direction using radio wave remote control. It was hard for people to believe this technology and started calling it magic, telepathy, and being piloted by a trained monkey hidden inside the boat. But in reality, the boat was powered by dc batteries in it and Tesla was just controlling it by remote. 

07-Wireless Power

Design of Magnifying Transmitter

Tesla was obsessed with wireless power transmission. Though inductive and capacitive coupling work for near field transmission but they are not convenient for long-distance. Being obsessed with long-distance wireless power transmission, he published his visions regarding this. Tesla had claimed that his model can transmit power worldwide. The atmosphere and the Earth would work as a conductor as he believed that the entire Earth could work as an electric resonator and that by driving current pulses into the Earth at its resonant frequency from a grounded Tesla coin with an elevated capacitance, the potential of the Earth could be made to oscillate, creating global standing waves, and this alternating current could be received with a capacitive antenna tuned to resonance with it at any point on Earth. But there is no evidence that this project was successful.

08-Bladeless Turbine

Tesla Turbine

Conventional compression turbines offer less efficiency. Tesla built a turbine that consists of multiple disks. It had no blades in it. The specialty of this turbine is that the fluid here moves in neutral paths or streamline of least resistance. During that time, Tesla demonstrated a 200 HP (1500 KW) 16,000 rpm bladeless turbine. But this turbine was refused to put in the application grounds giving the excuse of its complexity.  

09-Hydroelectric Power Plant

Tesla Hydroelectric Power Plant at Niagra

Tesla was one of the pioneers in the renewable energy sector. he didn't believe that fossil fuels can be a better solution to the energy crisis. The Niagra Falls Commission made a project to generate power from the falls. First, they considered Edison's DC current but after Tesla's success on AC, the gave the contract to Westinghouse Electric Company. The design was taken from Tesla and finally, it worked out. 

Adam's Power Plant Transformers

Wait for the next article to know about the War of currents.

Get to know more about Tesla's invention from this video.

Image Sources:

* Polite BastArt

* SchoolWorkHelper

* Pinterest

* Energy News Network

* Nicola Tesla

* View Images

* Science Stamps and Musings

* Engadget

* ResearchGate

* Wikipedia

* Tesla Science Center

* David J. Kent

Reference Articles:

* Nikola Tesla

* The Nikola Tesla Invention CNN

* Inventions & Experiments of Nikola Tesla

* Nikola Tesla Wikipedia

* Nikola Tesla History

* History of Tesla Coil

* The Rise and Fall of Nikola Tesla and his Tower

* Tesla Turbine

Do you remember the scene in the famous movie 'The Prestige' directed by Christopher Nolan, where Tesla has been projected as the picture above? Nikola Tesla is one of the most brilliant inventors in the world. Alternating Current, Induction Motor, Tesla Coil, 3 Phase System, Remote Control, Neon Lamp, and what not! Frankly speaking, the credit of the modern & sophisticated electrical system goes to him. He was a prodigy ahead of his time but the world couldn't give him the proper feat.

A Little History:

Tesla (1856-1943) was a Serbian-American engineer & physicist. He studied Maths & Physics at the Technical University of Graz and philosophy at the University of Prague. He started his career with the job of repairing Direct Current (DC) power plants with the Continental Edison Company. Throughout his life, he proved his excellency but unlike others, he didn't possess the trait of "Business Mind ". Consequently, he could never gain the fame and the chance to be a billionaire. He couldn't even patent many of his works!

After witnessing the continuous betrayal and selfishness of cruel people, this genius, at the end of his life, became obsessed with pigeons especially with a white female one! He believed to have communication with the pigeons. He breathed his last in a hotel in New York working on his last inventions even with his energy and mental health faded. 

Tesla Vs Tesla:

Nikola Tesla himself was his own competitor. He believed his mind to be without equal! And he had proved that through his inventions. While the whole world was fascinated with DC, Tesla thought of AC and till now it has been the worldwide accepted electrical system. Can you believe that he got the idea of brushless AC motor while walking and had made the sketches of rotating electromagnets in the sand of the road!!!

Tesla's contribution to modern electric development can not be denied. Many futuristic works have been carried out based on Tesla's researches. Follow the link to know about the background of some of the most used machines in our day to day life; Tesla's Vision: Inventions Ahead of Time 

Image Source:

* Pinterest

* Interesting Engineering

Previously we're talking about Ultrasound Sonar Sensor (HC-SR04) that could detect the presence of an obstacle and could measure the distance also. Compared to the well-known 'Bug-eye' sensor HC-SR04, we've got another less familiar sensor form Maxbotix, namely Ultrasonic Range Finder-LV-Maxsonar-EZ series; EZ0, EZ1, EZ2, EZ3, EZ4.

Maybe you're taking it just as another product from a different manufacturer but does that really satisfy your curious mind? Don't you want to know what's different in it? Spare some of your time and quench your thirst.

What's Inside?

The basic working principle of this one is the same as HC-SR04 but the input and output controls are different and as you can see there is only one transducer while HC-SR04 had 2 of them. Moreover, it has 7 pins.

Pin No.	Pin Name	Description
1	BW	This should be kept low or open for serial output on Tx. If kept high, Tx will send pulse instead of serial data
2	PW	Pulse width representation of the range
3	AN	Analog output voltage with a scaling factor of Vcc/512 per inch
4	RX	Internally pulled high. The sensor will stop ranging if Rx is held low
5	TX	Delivers asynchronous serial with RS232 format
6	Vcc	2.5V~5.5V input power
7	GND	Ground

What's different?

This one is a little bit costly (~30$). But this module provides better facilities.

▶ Short to long-range Detection: Detects objects from 0-254 inches (6.45m)

▶ Sonar Range Information: From 6-254 inches with 1-inches resolution. Objects from 0-inches to 6-inches typically range as 6 inches

▶ Operating Frequency: 42KHz

▶ Quality Beam Characteristics: EZ0 holds the maximum sensitivity and wide beam pattern among the EZX series. The beam gets narrower in the subsequent models. Check datasheet for the beam patterns.

▶ 3 Different Outputs: The sensor provides continuously updated Analogue, Pulse Width & RS232 serial data when it is allowed to operate in the default mode of operation (free-run).

▶ Multiple Sensor Chain: One can use multiple sensors in a single system. The outstanding feature is that MaxSonar provides a way to avoid cross-talk and interference. There are 3 ways to make the chaining.

    ▶ AN output constant loop: The sensors will be triggered sequentially for ranging.

    ▶ AN output commanded loop: The sensors are triggered sequentially and the last one again triggers the first one thus creating an infinite loop.

    ▶ AN output simultaneous operation: All the sensors are triggered at the same time.

Working Principle:

The operating principle of this sensor is pretty simple. One just needs to send the trigger through the Rx pin. The sensor runs on a cycle of 49ms.

Image Source:

* TechBazar

* MaxBotix

* ece.ucsb.edu

Writing documents, reports or assignments is a need in our daily life. Whenever any writing issue pops up, we rush to open MS Word. No doubt MSW provides a variety of options to decorate your text. But there is an 'Elite member' in the family of writing editor software. Yes, and that is the LaTeX (pronounced Lay-tech) project!

What makes LaTeX different?

What will you think if someone says that you have to write codes to create a document! Just imagine in the MSW you have to write codes rather than sentences. LaTeX is somewhat like this. It is a document preparation system for high-quality typesetting. It is mostly used for technical or scientific documents. Unlike other editors, LaTeX requires markup tags to to design the document. And this feature makes it different from other software. It doesn't go with the What You See Is What You Get (WYSIWYG) policy.

I hate coding!

Now it may be a passionate practice for the dedicated coders to use LaTeX while majority wants to avoid coding and for a simple document writing, who wants to take the pain of coding. Though coders may get angry as I'm addressing markup tagging as coding (!) but it's undoubtedly troublesome. Let us have a look why we need to prefer LaTeX.

Suppose you are writing a report in MSW. When you have plenty of options, you will surely want to present your document in the best manner. For this you will use different font size, style, color, etc.

This gives you two options;

✎ Your document may have an outstanding look but for this purpose you have wasted plenty of time.

✎ Both your design and time are wasted due to your poor designing sense and the document takes a horrible look!

LaTeX saves you from these problems. Here you need to focus on the content only and the necessary designs are done automatically by the software as it has an integrated designer.

LaTeX input & output

LaTeX provides different additional software for proper functioning. Two fundamental things LaTeX require are, 

✎ Converter: The markup tags need to be converted to document. This converted contains the necessary tools to do the job. The preferred one is the MikTeX.

✎ Reference Manager: For research documents and academia papers, attaching references are mandatory. Software like Mendeley, Jabref  do the management and citation of the references. But these are also managed in the LaTeX. For that BibTex is integrated. It is a reference management software for formatting lists of references.

The LaTeX Projects provides the features as;

⌀ Typesetting journal articles, technical reports, books & slide presentations.

⌀ Control over large documents containing sectioning, cross-references, tables and figures.

⌀ Typesetting of complex mathematical formulas.

⌀ Advanced mathematical typesetting with AMS-LaTeX.

⌀ Automatic generation of bibliographies and indexes.

⌀ Multi-lingual typesetting.

⌀ Inclusion of artwork and process or spot color.

⌀ Using postscript of meta-font fonts.

Nomenclature!!

You might growing curious thinking what kind of awkward name LaTeX is! What does it mean actually? The temr TeX is derived from the ancient Greek τέχνη meaning skill/art/technique. Indeed it expresses the uniqueness of the software, don't you think so?

Now it's up to you to decide whether you want to carry the pain or achieve the asset! Wait to know about the user interface of LaTeX.

Image source:

* Wikipedia

* Clean PNG

মৃত্যু; এক অনিবার্য সত্য মানুষের জীবনে। শুধু কী মানুষের জীবনে? মৃত্যু তো সবারই হয়। হ্যা তা হয় কিন্তু শেষ নিঃশ্বাস পর্যন্ত বাঁচার আশা আর স্মৃতি ধরে রাখার গুণটি মানুষেরই আয়ত্তে। জহির রায়হান তার স্বল্প পরিসরের গল্পের মধ্যে জীবনের কঠোর সত্যগুলো তুলে ধরেন। তেমনি কয়েকটি মৃত্যু গল্পে মৃত্যুর আশংকায় শঙ্কিত কিছু মানুষের স্বার্থপর চেহারা তুলে ধরেছেন।

গল্পের পটভূমি বুড়োকর্তা আহমেদ আলী শেখের পরিবারকে নিয়ে। চার সন্তান ও নাতি নাতনীদেরকে নিয়ে বুড়োকর্তার সুখী পরিবার। কোন এক আনন্দঘন রাতে বুড়োকর্তার দেখা এক দুঃস্বপ্ন পারিবারিক সম্পর্কগুলোকে ওলটপালট করে দেয়। স্বপ্নটি সাধারণ কোন স্বপ্ন নয় বরং বুড়োকর্তার বাবা ও ভাইকে হারানোর অতীতের এক কালো সংকেত; পরিবারের কারো মৃত্যুর সংকেত!

পারিবারিক সম্প্রীতির আড়ালে স্বার্থপর চেহারা উন্মোচিত হয়। স্বামী-স্ত্রীর মাঝের দূরত্ব স্পষ্ট হয়ে ওঠে! সম্পত্তির নেশায় ভাইয়ে ভাইয়ের সম্পর্কে চিড় ধরে। সম্পর্কের এই পালাবদলে শুধু পালটায় না বাবা-মা এর সন্তানের প্রতি স্নেহ ভালোবাসা। বুড়োকর্তা ও স্ত্রী জোহরা তখনও প্রার্থনা করে নিজেদের জীবনের বিনিময়ে সন্তানের জীবন বাচানোর!!!

লেখক এই গল্পের ইতি টেনেছেন মৃত্যুর মধ্য দিয়ে নয় বরং সৃষ্টির মধ্য দিয়ে। বাড়ির পুরাতন চাকর আব্দুলের যমজ বাচ্চার জন্মের মধ্য দিয়ে গল্প শেষ হয়। কিন্তু আসলে এই সৃষ্টি নবজাতকের নয়। এ সৃষ্টি  বুড়োকর্তার পরিবারের সবার। মিথ্যে ও ঠুনকো পারিবারিক সম্পর্কের মৃত্যুর মধ্য দিয়ে প্রকৃত সম্পর্কের সৃষ্টির রূপক এই নবজাতক বলে আমি মনে করি। 

প্রিয় উক্তিঃ- 

 

"উত্তেজিত করছি কি আর সাধে! ঘরে ছেলেপেলেগুলো আছে তাদের কথা আমাকে ভাবতে হবেনা? খোদা না করুক আজকে যদি তোমার কিছু একটা হয় তাহলে ওদের নিয়ে আমি দাঁড়াবো কোথায়? "

"আশ্চর্য । আমি মরে গেলে আমার মৃত্যুটা তার কাছে বড় নয়। বড় হল কেমন করে সে খাবে। পড়বে। বাঁচবে।"

 

 

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Imagine a day without electricity! Irritating! disgusting!! and you feel so much helpless. Picking up your phone and gadgets and suddenly you remember "Oh! there is no electricity" It's disheartening right? We shout, blame the provider but don't try to understand why our loads are being shaded. To grab an idea, let's try to understand how the generated electricity is at our door; the concept of Grid System.

What is Grid?

You must have seen generators in shops, complexes, offices, markets, etc. When the electricity is out, they are used to provide a backup. But where is the generator that provides electricity to the whole country? Is there only one generator or several? The answer is, there are numerous generators connected together to serve the country. And the way they are connected to each other and to the users' end is known as grid. Therefore, grid is an interconnected network with different components working together.

How does grid works?

As we all know there are 3 blocks of operation generating station to users' end i.e. Generation, Transmission, Distribution. Let's discuss one by one.

☛ Generation: Electrical energies are generated, actually not generated but transformed from other sources (water, coal, gas, nuclear, etc.) by mechanical means.

Hydro-electric Power Plant

There are numerous power plants all over the country like this. The output from these stations are connected to different nodes create a common energy bus. The transmission system starts from here.

☛ Transmission: The generated electricity is stepped up to a higher potential of about 33 KV through transformers for transmitting to a long-distance without a severe drop in the transmission line.

Transmission

☛ Distribution: These high voltage transmission wires end in substations outside the towns. There, with the help of step down transformers, the potential is stepped down to 11 KV Again they are stretched to the substations inside the town and stepped down to 220 V (3 phase 4 wire), and then single-phase supply is provided to the houses. The three-phase supply (11 KV) is given to the industries on demand. 

Power system 

This diagram shows the entire system from producer to consumer. And the entire network with all these components is called Grid. All the generating stations contribute to the grid and also work as a backup for other stations. Many interesting topics are related to this grid. Or do you think it's so simple as stated above! 

When I studied Grid System, a number of questions came in my mind that why it is necessary to interconnect so many generators together? Can't a single generator serve the purpose? And why different countries have separate grids? Why not a single grid is created all over the world that connects all the countries?

Do you also have these questions in your mind? If so,  stay with us and find your answers. 

Image Source:

* Circuit Globe

* Giphy

So, we're talking about the steps to form a design in COMSOL. And after a hazy discussion, we were left with 2 subnodes; Component & Study in the Model Tree. The immense significance of these 2 nodes calls for a separate discussion. Don't you think so? Let's first talk about the Study!

According to our early discussion, we know that the Study sets up the solver type (i.e. Stationary, Time-dependent, Frequency-dependent, etc.).

Model Wizard automatically creates the nodes under Study while simulation. Additional studies can be added from the study tab from the Ribbon.

So, we can switch between different studies and compute. Each study has a Compute button to run simulation for the selected study. The settings & boundary mode operations and configurations can be set here. It is very much important to simulate the model with the correct study. The result nodes will be added as per the selected study.

Coming to the Components node, it comprises of multiple sections as;

✦ Definitions: Defines the variables, boundaries, system selections, and their modifications.

✦ View: It gives the axes settings.

✦ Geometry: Gives the necessary options to build the model.

✦ Materials: Materials property like refractive index and others can be specified here. You can also add material in this node.

✦ Mesh: The whole model is divided into numerous small nonoverlapping elements. The behavior model is approximated by assembling all the elements' behavior. As COMSOL is based on the Finite Element Method (FEM), it is highly dependent on meshing. Here we can select the mesh type (rectangular, triangular, square, etc.), their size, and the relative setups.

✦ Physics: Gives selection options based on the selected Physics.

✦ Variables: Numbers, parameters, built-in constants, unary and binary operators can be set as Global or Local variable. Variables are listed under the Definition tab. Too many variables can be grouped together using the Node Group feature.

In the next segment, we will try to design a model. Till then explore & learn. Keep in mind, software can't be taught by articles. These articles are to provide a guide. One has to learn the software by exploring it.

And be with us for the next article and yes don't forget to check out the tutorial video: A simple Model in COMSOL Multiphysics on youtube.

Image Source:

* COMSOL Multiphysics