WAZIPOINT Engineering Science & Technology: 2018

Thursday, December 27, 2018

ক্যাপাসিটর এবং ব্যাটারির মধ্যে পার্থক্য কি?

What Is the Difference between Capacitor and Battery?

ক্যাপাসিটর এবং ব্যাটারি উভয়ই চার্জ জমা করলেও পার্থক্য রয়েছে বেশ

একটি ব্যাটারি বা একটি ক্যাপাসিটার উভয়ই চার্জ শক্তি স্টোরেজ উপাদান। কিন্তু, তারা সত্যিই একে অপর থেকে ভিন্ন।  

একটি ব্যাটারি রাসায়নিক-শক্তি আকারে শক্তি সঞ্চয় করে, যেখানে ক্যাপাসিটর ইলেকট্রস্ট্যাটিক ক্ষেত্র (field) ব্যবহার করে। 

একটি ব্যাটারি সাধারণত  শক্তির ঘনত্ব অনেক বেশি, যার অর্থ একক ঘনত্বে অনেক বেশি শক্তি সঞ্চয় করতে পারে। 

ক্যাপাসিটাররা যদিও অভ্যন্তরীণ প্রতিরোধ ক্ষমতার ক্ষেত্রে অধিক উচ্চতর হয়, যা স্বল্প সময়ের জন্য অনেক বেশি শক্তি সরবরাহ করতে পারে। 

একটি ব্যাটারি সাধারণত তার টার্মিনাল জুড়ে একটি ধ্রুবক (constant) ভোল্টেজ বজায় রাখে, এটি প্রায় সম্পূর্ণরূপে নির্গমন হয় যখন ভোল্টেজ ড্রপ হয়ে যায়। ক্যাপাসিটরে যেখানে মুহূর্তের মধ্যে ভোল্টেজ ড্রপ শুরু হয়। 

একটি ক্যাপাসিটর  ফিল্টারিং অ্যাপ্লিকেশনএর জন্য ব্যবহার করা যেতে পারে। 

একটি ব্যাটারি সবসময় একটি পোলারিটি থাকে। 

 অনুরুপ ভাবে, এই তালিকাটি আরও লম্বা করা যাবে, কিন্ত আমি এখানে থামাতে চাচ্ছি।



অবশ্য, সম্প্রতি  শক্তির উৎস হিসাবে সুপার-ক্যাপাসিটারগুলি ব্যবহার করা শুরু হয়েছ, তাছারা শক্তির সংক্ষিপ্ত বিস্ফোরণের জন্যও ক্যাপাসিটর ব্যবহার করা হয়, যা বেশ মজারই বটে!

ব্যাটারি একটি সক্রিয় ডিভাইস, যা একটি সার্কিটে (power / energy)  সরবরাহ করে। ক্যাপাসিটর একটি প্যাসিভ উপাদান। তবে উভয় এই শক্তি জমা করে রাখে। শক্তি সঞ্চয়ের জন্য তাদের ব্যবহার তুলনা করা যেতে পারে।

 ব্যাটারি শক্তি সঞ্চয়ের জন্য ইলেক্ট্রোকেমিক্যাল ডিভাইস। এটি সংরক্ষিত  রাসায়নিক পদার্থ চার্জ করার সময় বৈদ্যুতিক শক্তি ব্যবহার করে। যখন নিষ্কাশন বা ডিসচার্জ হয় তখন বিপরীত রাসায়নিক ক্রীয়া হয়। উভয় চার্জ / ডিসচার্জ প্রক্রিয়াগুলিতে রাসায়নিক প্রতিক্রিয়া থাকে।

ক্যাপাসিটর, প্রদত্ত ভোল্টেজের জন্য বৈদ্যুতিক চার্জ হিসাবে বৈদ্যুতিক ক্ষেত্রে শক্তি সঞ্চয় করে।  দক্ষতার ক্ষেত্রে ক্যাপাসিটর  98% ছাড়িয়ে যেতে পারে। সুপারক্যাপ্যাসিটারগুলি এভাবে 98% এরও বেশি দক্ষতার সাথে প্রচুর পরিমাণে শক্তি সঞ্চয় করে এবং এর পুন:রাবৃত্তি ঘটে।

ক্যাপাসিটর এবং ব্যাটারি মধ্যে পার্থক্য কি?


1। ব্যাটারি একটি বর্তনী জন্য শক্তি উৎস, ক্যাপাসিটরের একটি প্যাসিভ উপাদান, যা বর্তনী থেকে শক্তি আঁকা, দোকান এবং এটি মুক্তি।

2। সাধারণত ব্যাটারি একটি ডিসি কম্পোনেন্ট হয়, ক্যাপাসিটার অধিকাংশই এসি অ্যাপ্লিকেশনের জন্য ব্যবহৃত হয়, যখন।এটা সার্কিট মধ্যে ডিসি উপাদান ব্লক ব্যবহৃত হয়।

3। বিচ্ছিন্নকরণের সময় ব্যাটারি অপেক্ষাকৃত ধ্রুবক ভোল্টেজ প্রদান করে, যখন ক্যাপাসিটারগুলিকে নিঃসরণ করার জন্য ভোল্টেজ নিঃসরণ দ্রুত হ্রাস পায়।





Thursday, December 13, 2018

List of ACSR Conductor Sizes as per ASTM Standard

ACSR (ALUMINUM CONDUCTORS STEEL REINFORCED)  Conductor Sizes and Specification List as per ASTM Standard

Normally animals names are used to descrive the ACSR conductrs. It is used in only a few countries and has as usual no scientific or  any other background.

The animal names are a short-cut way of describing various  standardized overhead power distribution lines, as typically used by  utilities.

Monday, December 10, 2018

How Protect Copying Blog Contents

How Protect Your Blog Post Images and Contents Being Copied from Spammers or Illegal Copier

Copying blog contents is controversial issue today, some blogger says visitors will come to the blog and they will read, copy contents as their requirement. On the other side, most of the bloggers strictly refuse to copy their blog contents without their permission. They treat it as a stealing blogger’s property.

Protect Blog Contents from Copying by others What is right where million-million tons of information are free available in the internet and people have no time to ask who the owner of it is. How will they take permission to copy a blog contents. But everybody will agree with it that copying something from others and publish as own, is not acceptable. For that reason, sometime its need to copy protect your blog contents.  It will be your own technique how and what you want to protect.

Someone who related with photography he wants to protect image copying rather than other contents. As a photographer or an artist, who make money from it obviously he wants to prevent copying his photo. Similarly other blog writers prefer to protect his/her blog contents than images.

Reality is, there is no way of stopping people from using your images or blog contents completely, while Google and others sharing sites are making more and more easy to sharing images and documents. So people thinking, something images or documents coming in Google search means fair to use.

Regarding copying image or other materials, someone agree to just motivating sending a message to “not copying other’s property”. Some others like to protect copying by disabling ‘right-click’ & content selection, ‘watermark’ for images, ‘disable hot linking’ etc. Also some expert blogger take reverse action to who copy-paste their blog contents using tools like DMCA banner, Plagiarism, Tynt.com ect. Using these tools owner of the contents sometimes get SEO beneficiary such increasing visitors, sometimes copier get looser going his site down and down on traffic.

So, you are a blogger, you have right to protect your blogs. You must set your mission to protect your blog’s contents. There are many plenteously of ways to protect your blog property from contents copier or spammers who are diverting your visitors to them.

There are many ways to copy protect your blog. Now, let know some of simple and easiest way to protect blog contents from copier.
  

Disabling Right-Click & Selection to Protect Copying


Downloading or copying images by right clicking is the easiest way, just right click on the image and select ‘save image as’. So, you can disable right click and visible a massage to copier not copying. But, this is not a permanent solution, while it’s still easy enough to copy the images in alternate way. You can just protect mass copying.

Disable Content Selection: Only disable right-click is not safe your blog data. Someone can copy from source code, this is the reason why you disable both right-click and content selection. Selecting this way, the contents copier cannot select your blog data and even not copy from source code.

But remember, there are so many expert blogger they can break your protection easily and copy the blog contents.

To apply copy protect in your own blog copy the following codes and paste anywhere using “Add a Gadget” & HTML script in your blog. Before using you can visit and try to copy an image, see how it works.

<script language=javascript>
<!--
//Disable right mouse click Script
//By Being Geeks
//For full source code, visit http://wazipoint.blogspot.com
var message="No Copy, Share Please!";
///////////////////////////////////
function clickIE4(){
if (event.button==2){
alert(message);
return false;
}
}

function clickNS4(e){
if (document.layers||document.getElementById&&!document.all){
if (e.which==2||e.which==3){
alert(message);
return false;
}
}
}
if (document.layers){
document.captureEvents(Event.MOUSEDOWN);
document.onmousedown=clickNS4;
}
else if (document.all&&!document.getElementById){
document.onmousedown=clickIE4;
}
document.oncontextmenu=new Function("alert(message);return false")
// -->
</script>

Protect Copying Adding DMCA Banner

The best and easiest way to protect your blog’s contents from being copied by spammers or illegal blog-copiers. An intelligent blog copier never like to copy blog contents from a Blog with DMCA badges.

DMCA banner works like a string trap and able to attack the copied site, who copied the contents and paste his blog, that site will go down and down what we said before.
To get this DMCA, visit www.dmca.com and copy the DMCA badge from it and put on your blog, that’s enough. DMCA will act on your behalf as a deterrent for image stealers.

Plugging Tools Can Help to Protect Copying

 You can use a suitable plagiarism tools like copyscape, plagspotter, images.google.com etc to check the copied contents, which will give you the link of similarities with sites URL address, easily you can find out who copied your blog contents, then you can take action against to them.

There are many plugging sites who provide free services, you also can get paid pro services. Most of them provide much information by free tools that enough you to.

Being Obsessive not Bring Good Something



You can take precautions to protect your blog property where you paid lots of lime, but don’t be obsessive. Be happy thinking that someone copying your contents means you are delivering good something where many peoples are trying to that.

It’s not wise to waste your time trying to achieve something impossible, better to try delivery better. If you think your position there to delivery paid service, do that. People will pay to you.

Tuesday, November 6, 2018

Motor and Pump Application Formula Save Energy and Make You Smart Designer


How Motor and Pump Application Formula can Save Energy and Make You Smart Designer?

Motor and Pump applications simple formula can save energy by helping effective design for using maximum efficiency of your equipment. 


Some times we ignore these basic design formula and use larger size of equipment using thump-role formula which cases extra money energy as wastage. 



A gerotor
A gerotor (image does not show intake or exhaust) (Photo credit: Wikipedia)
If we love ourself to be a energy saver or go to as green environment; we should take care of every bit of energy uses. Following motor and pump applications formula can help us to effective use of energy.

Centrifugal Applications


AFFINITY LAWS

The Affinity Laws of centrifugal pumps or fans indicates the influence on volume capacity, head (pressure) and/or power consumption of a pump or fan due to


  • change in speed of wheel - revolutions per minute (rpm)
  • geometrically similarity - change in impeller diameter
Following three affinity formulas are related with simply motor horse power, RPM (revolution per minute), Flow and pressure.

Flow2
=
RPM2
Flow1
RPM1
Pres2
=
(RPM2)2
Pres1
(RPM1)2
HP2
=
(RPM2)3
HP1
(RPM1)3


Where:
Pres=Pressure
RPM= Revolutions Per Minute

FANS AND BLOWERS


Centrifugal Fans and Blowers typically have one of seven types of wheels that draw the air into the inlet of the blower housing, through the wheel, and discharges it at 90 degrees out through the discharge of the housing.

The two most common types of Centrifugal Blowers are Pressure Blowers and Volume Blowers.

Fans and Blowers are very common uses in industry, Basic three formula can help you to design effective and perfect size of fan and blower as your desired. 

HP  =
CFM x PSF
33000 x Efficiency of Fan
HP  =
CFM x PIW
6356 x Efficiency of Fan




HP  =
CFM x PSI
229 x Efficiency of Fan



Where:
CFM= Cubic Feet per Minute
PIW= Inches of Water Gauge
PSF= Pound per Square Foot
PSI= Pound per Square Inches

PUMPS

Pump is a device that moves fluids (liquids or gases), or sometimes slurries, by mechanical action. Pumps can be classified into three major groups according to the method they use to move the fluid: direct lift, displacement, and gravity pumps.

Perfect capacity of pump design and operation is very important which can help the following two simple formula.


HP  =
GPM x FT x Specific Gravity
3960 x Efficiency of Pump



HP  =
GPM x PSI x Specific Gravity
1713 x Efficiency of Pump




Where:
FT= Head in Feet
GPM= Gallons Per Minute
PSI= Pounds Per Square Inch

VOLUME OF LIQUID IN A TANK


Gallons= 5.875 x D2 x H
1 gallon (US) of water weights 8.33 lb
Specific gravity of water- 1.0

Where:
D= Diameter of Tank in feet
H= Height of liquid in feet

Motor Application Formulas

Following motor applications formula is necessary everyday every moment.  It will help to calculate your motor's HP (Horse Power), Kilowatts, Torque in Pound-feet or Newton-meter.

HP(Horse Power)  =
Torque (lb-ft) x RPM
5252



Kilowatts  =
Torque (N-m) x RPM
9550




Torque (lb-ft)  =
Horse Power (HP) x 5252
RPM



Torque (N-m) =
Kilowatts x 9550
RPM




1HP= 746 watts
Hope motor and pump application formula will help to design a smart and effective energy saving initiative. 

Friday, October 19, 2018

HOW CALCULATE CAPACITANCE OF TWO PARALLEL CABLES


How Calculate Capacitance of Underground Power Cable?

 Capacitor is nothing but a two parallel metal plate separated by a dielectric that store electrical energy; formally we can define capacitor is a passive two terminal electrical component that used to store energy electrostatically in electric field, it also known as condenser. Practically a capacitor usually used a thin films of metal, aluminum foil or disks, etc.

The property of capacitor is known as capacitance, means the capacitance is the ability of a body to store an electric charge. The unit of capacitance is farad, symbol of farad is F, mostly common is micro farad µF.

The formula to calculate the capacitance between two cables is as
C = (Permittivity*Area)/D,

Where, A is the area is that of one cable, D is the distance between the center of the cable and the permitivity is that of the material between the cables.

Capacitance may measure as
C= Q/V= Charge/Potential difference.

How Calculate Single Core Cable

Let,r = radius of the inner conductor and d = 2rR = radius of the sheath and D = 2Rε0 = permittivity of free space = 8.854 x 10-12εr = relative permittivity of the mediumConsider a cylinder of radius x meters and axial length 1 meter. x be such that, r < x < R.Now, electric intensity Ex at any point P on the considered cylinder is given as shown in the following equations.Then, the potential difference between the conductor and sheath is V, as calculated in equations below.After that, capacitance of the cable can be calculated as C= Q/V
Single Core Cable Capacitance calculation Formula

Capacitance Between Two Parallel Cables

Practically in electrical transmission lines both in overhead and underground cable system. Simply we can find two wire system both in dc or ac type. If the transmission system so long and voltage is high, charging current drawn by the metallic line conductor due to their capacitance property between two conductors.

If two conductor A & B are placed apart distance between d, consider r is radius of  each conductor, Q is the charge in conductor/meter (if +Q at A & –Q at B); then electric intensity

= Q/ (2π€0€rx) V/m

How Calculate Capacitance Of Three Core Cable 

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Consider a three cored symmetric underground cable as shown in the following figure (i). Let Cs be the capacitance between any core and the sheath and Cc be the core to core capacitance (i.e. capacitance between any two conductors).
Three Core Cable Capacitance Calculation Formula

In the above figure (ii), the three Cc (core to core capacitance) are delta connected and the core to sheath capacitance Cs are star connected due to the sheath forming a single point N. The circuit in figure (ii) can be simplified as shown in figure (iii). Outer points A, B and C represent cable cores and the point N represents the sheath (shown at the middle for simplification of the circuit).



Therefore, the whole three core cable is equivalent to three star connected capacitors each of capacitance Cs + 3Cc as shown in fig. (iii).The charging current can be given as,Ic = 2πf(Cs+3Cc)Vph      A

Measurement Of Cs And Cc

In order to calculate Cs and Cc we perform various experiments like:
  1. First, the three cores are connected together and capacitance between the shorted cores and the sheath is measured. Shorting the three cores eliminates all the three Cc capacitors, leaving the three Cs capacitors in parallel. Therefore, if C1 is the now measured capacitance, Cs can be calculated as, Cs = C1/3.
  2. In the second measurement, any two cores and the sheath are connected together and the capacitance between them and the remaining core is measured. If C2 is the measured capacitance, then C2 = 2Cc+Cs (imagine the above figure (iii) in which points A, B and N are short circuited). Now, as the value of Cs is known from the first measurement, Cc can be calculated.
To know more details about capacitor read or download pdf files

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