Peralatan Pengaman Pada Trafo

A. Relay Bucholz
Relay Bucholz adalah relai yang berfungsi mendeteksi dan mengamankan terhadap gangguan transformator yang menimbulkan gas.

Timbulnya gas dapat diakibatkan oleh beberapa hal, diantaranya adalah:
• Hubung singkat antar lilitan pada atau dalam phasa
• Hubung singkat antar phasa
• Hubung singkat antar phasa ke tanah
• Busur api listrik antar laminasi
• Busur api listrik karena kontak yang kurang baik.





 




B. Relai Tekanan Lebih (Sudden Pressure Relay)
Relai ini berfungsi hampir sama seperti Relay Bucholz. Fungsinya adalah mengamankan terhadap gangguan di dalam transformator. Bedanya relai ini hanya bekerja oleh kenaikan tekanan gas yang tiba-tiba dan langsung mentripkan pemutus tenaga (PMT). Alat pengaman tekanan lebih ini berupa membran yang terbuat dari kaca, plastik, tembaga atau katup berpegas, sebagai pengaman tangki transformator terhadap kenaikan tekan gas yang timbul di dalam tangki yang akan pecah pada tekanan tertentu dan kekuatannya lebih rendah dari kekuatan tangki transformator

Berikut ini  adalah gambar dari Rele Tekanan Lebih
1. Relay body
2. Equalizer

3. Metal bellows
4. Manual relief valve
5. Microswitch
6. Connection terminals
7. Terminal box



C. Relai Diferensial
Berfungsi mengamankan transformator terhadap gangguan di dalam transformator, antara lain adalah kejadian flash over antara kumparan dengan kumparan atau kumparan dengan tangki atau belitan dengan belitan di dalam kumparan ataupun beda kumparan.

D. Relai Arus lebih (Over Current Relay)
Berfungsi mengamankan transformator jika arus yang mengalir melebihi dari nilai yang diperkenankan lewat pada transformator tersebut dan arus lebih ini dapat terjadi oleh karena beban lebih atau gangguan hubung singkat. Arus lebih ini dideteksi oleh transformator arus atau current transformator (CT).



E. Relai Tangki Tanah
Alat ini berfungsi untuk mengamankan transformator bila ada hubung singkat antara bagian yang bertegangan dengan bagian yang tidak bertegangan pada transformator.



F. Relai Hubung Tanah
Fungsi alat ini adalah untuk mengamankan transformator jika terjadi gangguan hubung singkat satu phasa ke tanah.

G.
Relai Thermis
Alat ini berfungsi untuk mencegah/mengamankan transformator dari kerusakan isolasi pada kumparan, akibat adanya panas lebih yang ditimbulkan oleh arus lebih. Besaran yang diukur di dalam relai ini adalah kenaikan suhu.


H. Rele beban lebih
Rele ini berfungsi untuk mengamankan trafo terhadap beban yang berlebihan dengan menggunakan sirkuit simulator yang dapat mendeteksi lilitan trafo yang kemudian apabia terjadi gangguan akan  membunyikan alarm pada tahap pertama dan kemudian akan menjatuhkan PMT.

I. Rele fluks lebih 
Rele ini berfungsi untuk mengamankan transformator dengan mendeteksi besaran fluksi atau perbandingan tegangan dan frekwensi.


READ MORE - Peralatan Pengaman Pada Trafo

Are Student Loans Worth the Cost?

Aside from financial aid that colleges offer, there are also students loans that you can turn to in case you are in dire financial needs. Like any other type of loan, a student loan comes with interest rates attached to it. Many schools actually give a prime interest rate for student loan because of the fact that most students don't usually have credit history. This means that the repayment for this loan can be a bit costly. Do you think the benefits that you can get from applying for student loans are worth the cost? Read on and find out.
READ MORE - Are Student Loans Worth the Cost?

An afternoon on the dredge spoils





It's silly season--a pope getting beatified, royalty getting married. We need costumes for these, lots of costumes. And music! And, oh, isn't it all so grand!


And under the Delaware Bay stir the ancient longings of ancient critters, crawling up from the cool, dark muck, to dance under the moon again, as they have for millions of years.
I spent the afternoon atop a mountain of dredge fill, surrounded by the skeletal remains of horseshoe crabs and scallops, fish and whelk. Tiny flies congregated in the cracks, worshiping the death that keeps them alive. A hawk hovered a hundred yards away, eying the last moments of its prey below.

In the garden sits a robin's egg, intact but fading under two weeks of sun. A few volunteer basil plants erupted a few feet away. Last year's Brussels sprouts are now a riotous yellow.

Each time I wander outside, I am reminded how the story ends, as I am reminded how the story starts, a story without fine linen or fine music, and a story without end.



Every day I share pieces of the story with my students, and every day it surprises them, as every day, it surprises me.




 





Photos by us, use them as you will. Another beautiful day.
READ MORE - An afternoon on the dredge spoils

Transformator (Trafo)

Transformator atau transformer atau trafo adalah suatu peralatan elektromagnet yang dapat mengubah nilai  suatu tegangan AC ke nilai yang lain. Prinsip kerja dari sebuah transformator adalah sebagai berikut. Ketika Kumparan primer dihubungkan dengan sumber tegangan bolak-balik, perubahan arus listrik pada kumparan primer menimbulkan medan magnet yang berubah. Medan magnet yang berubah diperkuat oleh adanya inti besi dan dihantarkan inti besi ke kumparan sekunder, sehingga pada ujung-ujung kumparan sekunder akan timbul ggl induksi. Efek ini dinamakan induktansi timbal-balik (mutual inductance).


Rumus untuk fluks magnet yang ditimbulkan lilitan primer adalah \delta\phi=\epsilon\times\delta\,t dan rumus untuk GGL induksi yang terjadi di lilitan sekunder adalah \epsilon=N\frac{\delta\phi}{\delta\,t}.
Karena kedua kumparan dihubungkan dengan fluks yang sama, maka \frac{\delta\phi}{\delta\,t}=\frac{V_p}{N_p}=\frac{V_s}{N_s} dimana dengan menyusun ulang persamaan akan didapat \frac{V_p}{V_s}=\frac{N_p}{N_s} sedemikian hingga V_p\,I_p=V_s\,I_s. Dengan kata lain, hubungan antara tegangan primer dengan tegangan sekunder ditentukan oleh perbandingan jumlah lilitan primer dengan lilitan sekunder. Sedangkan untuk menghitung Efisiensi  transformator dapat diketahui dengan rumus \eta=\frac{P_o}{P_i}\,100% Karena adanya kerugian pada transformator. Maka efisiensi transformator tidak dapat mencapai 100%. Untuk transformator daya frekuensi rendah, efisiensi bisa mencapai 98%.


RUGI-RUGI 
Rugi-rugi atau Losses pada Trafo antara Lain
  1. kerugian tembaga. Kerugian I^2\,R dalam lilitan tembaga yang disebabkan oleh resistansi tembaga dan arus listrik yang mengalirinya.
  2. Kerugian kopling. Kerugian yang terjadi karena kopling primer-sekunder tidak sempurna, sehingga tidak semua fluks magnet yang diinduksikan primer memotong lilitan sekunder. Kerugian ini dapat dikurangi dengan menggulung lilitan secara berlapis-lapis antara primer dan sekunder.
  3. Kerugian kapasitas liar. Kerugian yang disebabkan oleh kapasitas liar yang terdapat pada lilitan-lilitan transformator. Kerugian ini sangat memengaruhi efisiensi transformator untuk frekuensi tinggi. Kerugian ini dapat dikurangi dengan menggulung lilitan primer dan sekunder secara semi-acak (bank winding)
  4. Kerugian histeresis. Kerugian yang terjadi ketika arus primer AC berbalik arah. Disebabkan karena inti transformator tidak dapat mengubah arah fluks magnetnya dengan seketika. Kerugian ini dapat dikurangi dengan menggunakan material inti reluktansi rendah.
  5. Kerugian efek kulit. Sebagaimana konduktor lain yang dialiri arus bolak-balik, arus cenderung untuk mengalir pada permukaan konduktor. Hal ini memperbesar kerugian kapasitas dan juga menambah resistansi relatif lilitan. Kerugian ini dapat dikurang dengan menggunakan kawat Litz, yaitu kawat yang terdiri dari beberapa kawat kecil yang saling terisolasi. Untuk frekuensi radio digunakan kawat geronggong atau lembaran tipis tembaga sebagai ganti kawat biasa.
  6. Kerugian arus eddy (arus olak). Kerugian yang disebabkan oleh GGL masukan yang menimbulkan arus dalam inti magnet yang melawan perubahan fluks magnet yang membangkitkan GGL. Karena adanya fluks magnet yang berubah-ubah, terjadi olakan fluks magnet pada material inti. Kerugian ini berkurang kalau digunakan inti berlapis-lapisan.
Jenis-Jenis Transformator
  • Transfoormator Step Up. Transformator step-up adalah transformator yang memiliki lilitan sekunder lebih banyak daripada lilitan primer, sehingga berfungsi sebagai penaik tegangan. Transformator ini biasa ditemui pada pembangkit tenaga listrik sebagai penaik tegangan yang dihasilkan generator menjadi tegangan tinggi yang digunakan dalam transmisi jarak jauh. 

    • Transformator step-down memiliki lilitan sekunder lebih sedikit daripada lilitan primer, sehingga berfungsi sebagai penurun tegangan. Transformator jenis ini sangat mudah ditemui, terutama dalam adaptor AC-DC.
    • Autotransformator. Transformator jenis ini hanya terdiri dari satu lilitan yang berlanjut secara listrik, dengan sadapan tengah. Dalam transformator ini, sebagian lilitan primer juga merupakan lilitan sekunder. Fasa arus dalam lilitan sekunder selalu berlawanan dengan arus primer, sehingga untuk tarif daya yang sama lilitan sekunder bisa dibuat dengan kawat yang lebih tipis dibandingkan transformator biasa. Keuntungan dari autotransformator adalah ukuran fisiknya yang kecil dan kerugian yang lebih rendah daripada jenis dua lilitan. Tetapi transformator jenis ini tidak dapat memberikan isolasi secara listrik antara lilitan primer dengan lilitan sekunder. Selain itu, autotransformator tidak dapat digunakan sebagai penaik tegangan lebih dari beberapa kali lipat (biasanya tidak lebih dari 1,5 kali).
       
    • Autotransformator variabel. Autotransformator variabel sebenarnya adalah autotransformator biasa yang sadapan tengahnya bisa diubah-ubah, memberikan perbandingan lilitan primer-sekunder yang berubah-ubah.
    READ MORE - Transformator (Trafo)

    Perennial projects

    At the start of the school year, back when the sunlight was fading and squirrels were fattening up, each student picked a tree to watch. Call it phenology, call it botany, call it whatever you want, but it's really just observing, and few of us do that well. I call it the Perennial Project.


    Some wise people back in the 1890's decided that biology should be the first course of science for high school students because biology was, back in the day, all about observing and categorizing living things. If you care to study the world, you need to learn how to look.

    [T]he elements of biology serve specially well as a means to cultivate the power of accurate observation (i.e., the exercise of perception regulated and clarified through direct subordination to reflection)...work specially adapted to exercise of judgment.



    That biology is now taught as something else does not deny the wisdom of the Committee of Fifteen.   Learning how to look is particularly relevant in a culture that encourages others to do your observations for you. Judgment without observation may be good for a consumer economy, but has predictably disastrous results for a functioning democracy. (I said functioning....)

    ***


    Kids occasionally need to be led by the nose, and asking them to spend a few minutes outside each week staring at a tree does require some external motivation, as prickly as that has become in the ultra-chic eduworld. I toggled the grades in a way that doing the observations helped a bit, but screwing up did not sink them.

    Kids need room to screw up, lots of room, especially when asked to stand outside staring at a stupid tree making this stupid drawing for this stupid class. Most students trust me, as they trust most teachers, despite a steady stream of evidence that the trust may be misplaced; I take advantage of this.

    This will go somewhere, I tell them. I promise.

    Then winter comes, and the trees, mildly interesting to some in autumn, "die." Now the stupid teacher wants me to stand in the stupid cold to draw a stupid picture of a stupid dead tree.

    A lot of them fake it. They do not know that I know, but (for the most part), I let it go. They put their drawings in a folder, and come mid-January, I stop asking for reports.


    Early March, I started it up again. Find a bud on your tree, measure it, draw it.

    They resist.What's a bud? I can't find one my tree doesn't have buds I can't reach it I have to catch a bus I have to babysit my little brother my tree is dead nothing is happening this is stupid it rained all week my tree is dead it's too small to measure I don't have a ruler....and I push back, a little. 

    A small change--a bud gets a little bigger, a little tighter. Kids are inherently curious. They start to watch.

    Then it happens--someone's bud blooms, and a child is astounded to see a flower from a tree, astounded enough to share it with the class. Then another child's tree blooms, then another. And they talk.

    I'm not going to pretend that all of the children get excited, nor that more than a few continue to fake it (and I continue to pretend I don't know this), collecting a paltry 9 or 10 points each week.

    Here's the unexpected part (for me): a few of the children are now writing voluminous reports, wonderfully descriptive logs with multiple drawings, because they want to, reminiscent of the meandering mind of Thoreau when he describes a particular plant:
    I observe the peculiar steel bluish purple of the night shade i.e. the tips of the twigs while all beneath is green dotted with bright berries over the water.
    This is how kids write when free from the 5 paragraph essay, from the fear of my grade book.

    This is how kids write when they take a moment, a long moment, to observe something that interests them. The words matter, and they struggle to find the words, because the observation matters more.
    ***

     
    We have a new superintendent here in Bloomfield, Jason Bing, who officially started less than 10 days ago. He's my 4th superintendent in the less than 5 years I've taught here. I expect good things from him, as he does from us, that's what professionals do.

    I have a concern, though, and it's not about him, it's about his contract. According to the local news, and it's all I have to go by at the moment, he can earn up to 15% more (over $25,000) "if the district meets five state testing benchmarks set by the BOE."

    State testing will not measure, cannot measure, the effects of my Perennial Project. Indeed, the flowery Thoreauesque descriptions interjected with pieces of a child's humanity could hurt a student on the writing portion of our state exams.

    The superintendent has been "incentivized"(Arne's word) to push up scores. Scores matter, for some very good reasons, but some things not (yet) measured by the tests matter more.

    Much more.






    I would love to post some of the students' work here--I'll see if I can get permission.
    READ MORE - Perennial projects

    Best universities and colleges for business in Sri Lanka

    Best university, colleges, schools and institutes. Top 10 and 20 university. These are the best colleges offering good degree courses and programs. These are best university list. Top colleges and best schools. Top university ranking. Leading university list in 2010 – 2011. Admission, Fee structure, entrance exam, marks. Accredited universities. These are famous and popular colleges. Under Graduate (UG) and Post Graduate (PG).
    READ MORE - Best universities and colleges for business in Sri Lanka

    Cargo! The Quest for Gravity (2011/ENG)



    Cargo! The Quest for Gravity (2011/ENG)

    License

    Language

    Publisher

    Support Game

    Genre

    Developer

    Date Released

    Size

    Created By
    : Free

    : English

    : bitComposer Games

    : PC

    : Arcade / 3D / 3rd Person

    : Ice-Pick Lodge

    : 2011

    : 884 MB

    : Syarief Hidayat


    --------------------------------------------------------

    Download Files : Part1 | Part2 [884 MB] | Fileserve

    Download Files : Part1 | Part2 [884 MB] | Unibytes
    ----------------------------------------------------------------------
    Keterangan : Dalam cerita Cargo! Quest untuk Gravity, para dewa akhirnya kehilangan kesabaran dan memutuskan untuk mengajarkan pelajaran untuk semua orang, mereka menyangkal hal yang paling penting - gravitasi. Sebaliknya, orang yang mereka terjajah makhluk gravitasi bumi yang tidak diperlukan. Kami akan bermain untuk seorang gadis bernama Phlox dan menemukan cara untuk menyelamatkan umat manusia semua.


    Persyaratan sistem:

    Sistem operasi : Windows XP / Vista / 7

    > Processor : Pentium IV 3 GHz

    Memory : 1 GB (XP) / 2 GB (Vista / 7)

    > Hard disk : 4 GB

    Sound perangkat : kompatibel dengan DirectX ® 9.0c

    Video Card : 128 MB memori grafis, ATI Radeon X800 / NVIDIA GeForce 7600





    Cargo! The Quest for Gravity (2011/ENG) Cargo! The Quest for Gravity (2011/ENG) Cargo! The Quest for Gravity (2011/ENG)




    READ MORE - Cargo! The Quest for Gravity (2011/ENG)

    Game



    READ MORE - Game

    Shaun White Snowboarding



    Shaun White Snowboarding

    License

    Language

    Publisher

    Support Game

    Genre

    Developer

    Date Released

    Size

    Created By
    : Free

    : English

    : Ubisoft Entertainment

    : PC Game

    : Sprt (Wntr sprts/Extrm sprts)/3D

    : Ubisoft Entertainment

    : 2008

    : 2.82 GB

    : Syarief Hidayat


    Download files : Part 1 | Part 2 | Part 3 | Part 4 | Part 5 | Part 6 | Part 6 | Part 7 | [2.82 GB] | Filesonic

    Download files : Part 1 | Part 2 | Part 3 | Part 4 | Part 5 | Part 6 | Part 7 | [2.82 GB] | Fileserve



    Snowboarding gaya hidup nya. Anak laki-laki dan perempuan, hari demi hari menempatkan diri pada risiko, pegunungan badai dan menantang puncak yang tertutup salju. Berusaha mencapai yang terbaik, gairah dan dorongan yang tak terkendali, meluap thats adrenalin apa yang mendorong mereka maju, dipaksa untuk melakukan chip yang paling gila di lereng curam dan dalam mengantisipasi jantung menyusut. Ingin bergabung dengan mereka? Kemudian permainan ini adalah untuk Anda!


    Stunningly realistis dan perhatian terhadap detail simulator snowboarding dikembangkan dengan bantuan dari juara Olimpiade dan pemberani, menyenangkan dan risiko pria Shaun White. Master mengakui olahraga ini, ia secara pribadi akan memberikan panduan yang berharga dan membantu untuk belajar bagaimana percaya diri berdiri di papan tulis! Ajarkan memusingkan stunts dan jungkir balik, klub mengangkat debu salju. Berikut adalah segalanya dari lereng klasik dan mengangkat ke taman terorganisir dan Street cukup turretless. Youll menemukan mil dari trek gila, Mouzon alternatif dan berkomunikasi dengan penggemar snowboarding.


    Fitur Game

    - Berdiri di papan tulis dan tantangan Shaun White

    - Jelajahi pegunungan di seluruh dunia dan menemukan bukit-bukit terbaik

    - Dimana dan dengan siapa naik nya Anda!

    - Menyusun partai nyata di Online



    Persyaratan sistem:

    Sistem operasi: Windows XP/Vista/7

    Processor: Pentium D 2,6 GHz atau setara AMD Athlon 64 X2

    Memory: 1 GB (2 GB untuk Vista)

    Video: 256 MB kompatibel dengan DirectX 9.0, atau 10,0 yang mendukung shader 3.0

    Kartu suara: kompatibel dengan DirectX 9.0 atau 10,0

    Free space pada HDD: 7 GB



    Fitur membungkus kembali

    - Audio Kualitas 100%

    - Kualitas video adalah 100%

    - Mulai permainan melalui shortcut pada desktop atau menu Start

    - Instalasi membutuhkan 512 MB RAM

    - Membungkus kembali oleh RG Repackers
    READ MORE - Shaun White Snowboarding

    Student Loan Consolidation – Lower Your Payments

    Often times it makes good economic sense to consolidate your all of your student loans upon graduating. Each of the loans that you applied for and received each year or semester of school is considered a separate loan. The average student graduating from a four-year private school leaves college with about $27,000 in student loan debt. After you graduate, you will get offers from lenders to consolidate these loans.
    READ MORE - Student Loan Consolidation – Lower Your Payments

    Allora and The Broken Portal (Final)



    Allora and The Broken Portal (Final) License : Free

    Date Released : 2011

    Language : English

    Publisher : Big Fish Games

    Support game : PC

    Genre : Hidden Object

    Size : 316 MB





    Download file [316 MB] | Filesonic

    Download file [316 MB] | Fileserve

    Seorang penyihir kuat telah tersedot ke portal dan hilang! Hanya Anda yang dapat menyelamatkannya dari takdir yang mengerikan di Allora dan The Broken Portal! Didekati oleh seorang gadis Elf dan seorang teman tikus, terserah pada mata manusia untuk memecahkan teka-teki membingungkan dan mengumpulkan kristal berharga bahwa kekuasaan portal. Gunakan Tersembunyi Obyek Puzzle Adventure bakat untuk melakukan perjalanan ke Jauh Hutan dan mengumpulkan item yang diperlukan dan menyimpan wizard!


    * Fantastic gameplay

    * Incredible grafis

    * Perbaikan Portal Broken!
    READ MORE - Allora and The Broken Portal (Final)

    Philly 2111-- April 29th

    READ MORE - Philly 2111-- April 29th

    Student Loans Consolidations - What Is The Best Company For You?

    CLICK HERE for the best info on Student Loans Consolidations

    Student Loan Consolidations
    Many students have benefited from financial aid.One form of this help is student loans. A student can have more then one loan with different lenders. Having more then one loan, each loan having it's own due date to be paid and IR. Having more then one loan with different billing cycles and interest rates would be confusing. So many loans could lead to some not being paid on time, eventually leading to a poor credit report. Student loan consolidation is the most effective way to handle these loans.
    students can consolidate their loans into a single loan. This new loan is handled by one company or creditor. The creditor pays the loan in full to the respective creditors leaving only the new loan. Because of this, when approved this can't be undone. Loan consolidation gives you the convenience of paying one loan to one creditor or company instead of paying multiple loans with different due dates and rates. Loan consolidation offers fixed rates and a longer payment period, usually ten to thirty years. A student can get his/her loan consolidation from the U.S. Dept of Education or any credit union or bank that is a part of the Fed Family Loan. Once a student graduates, they have six months before they should start re-paying their loan. It is expected that students find a job inside six months, so that they can start paying back the loan.
    There are three main advantages of a student loan consolidation program:-
    rates can be less than the average of all the student's multiple loans.
    Lower monthly payments.
    scholars save money.
    Loans are paid on time, avoiding the poor credit report that would affect the individual in the future.
    The drawbacks include :
    picking any loan consolidation company doesn't mean that you're saving cash. Some may provide lower monthly rates but a much longer payment period. These could mean paying more then saving.
    Some creditors may have hidden clauses. Always research on a creditor before allowing them to handle your student loans. Know their particulars of agreement, rates and penalties.
    It is vital to thoroughly research many firms before selecting a student loan consolidation company.It's best to start trying to find one before you graduate. You'll discoverinformation on such firms online or you can ask your College financial aid office. Asking graduates would also help you find a good lender. When bearing in mind student loan consolidation, gather as much info about your debt especially details of agreement, regular payments and rates. Once you have picked up all this financial information give this it to your selected creditor. Research on the web. Keep on searching until you find a company that you are feeling ok with. Compare their offers, quotes and policies. Know how their policies and process works. Applying with a creditor is the same as making an application for any loan. Make sure that you know the following : the fees, terms, rates and the penalties.

    .
    READ MORE - Student Loans Consolidations - What Is The Best Company For You?

    Letting Students Redo their Work Until it's Right



    One thing that I am in favor of is letting students correct their mistakes. English teachers do this when they allow students to write a draft, review it with the teacher and have someone edit it, and then fix it. This is also what happens in many jobs. You do it until it is correct. You work on something, your boss checks it, gives you feedback, and you make changes. As an engineer, we constantly had to make changes because things wouldn't work out at first. We would test it, note the issues, and then fix it.


    I think this should be done in education more. I don't grade my Physics or AP Physics students on the correctness of their homework. I grade it on effort. How complete is it? Did they at least set up the problems and try them? Then give them the answers. Depending on how well everyone did, we will go over them in class or I will go over a few to help them and then let them try the others again, in class, with me to help them, so that they can learn how to do it.


    In my AP Physics class, I give them back their tests and quizzes with the incorrect problems marked. I answer some questions and do some examples, and then have them take them home and try to get the correct answer. They get a few extra points added onto the original grade for doing this, and more importantly they learn.


    I use a lot of projects and labs in my classes. They don't just stop when done if it is wrong, or incomplete, or not working. They analyze it and make changes and try again.


    If a student doesn't get something right and can't fix it, they will often get discouraged and not try anymore or not "like" a class.


    Learning is the main purpose of education. Shouldn't we give them the chance to learn from their mistakes too and not just penalize them?




    UPDATED: Clarifications on what I do:


    1. They don't always get any kind of extra points and it's not a retest. I force them to learn the material. Many times, there is no extra points or improved grade for fixing their work. 

    2. There is no late policy. If their work is late, it is a letter grade off for every day late (just like at a job, if you are late, there are penalties and consequences). Some things are a zero (like homework) if not turned in on time. 

    3. If they come in asking about a retest or extra credit, they aren't getting any. This is to help them learn when they have tried. 

    4. I agree it is a case-by-case, situational decision. I don't do this with every test or assignment. But, it is important to have them redo to learn the material vs. just having a bad grade. 

    5. Not much extra time. They get graded, get it back, redo it, and turn it back in. It usually takes only a few minutes to check their wrong answers. I don't do it every time or with every level class so it's not a huge time commitment. 








    READ MORE - Letting Students Redo their Work Until it's Right

    Free Video Format Conversion Software (3 of them)

    Thumbnail for version as of 22:58, 31 October 2009

    Earlier today I posted about VLC Media Player, which can play, and convert, most video and audio formats. Sometimes you just want a simple video conversion software to convert video formats so that you can play the video on different devices and systems (Windows, Mac, Linux, mobile deviceHere are three:



    FLV Converter - converts Flash FLV video files to other formats (including Windows Media, .avi, and mpeg-4. Videos on many websites, including YouTube (for now) are in the FLV format. This format doesn't play well all the time and many video players can play it. If you download videos from YouTube or other sites, you may have to convert them to be usable.




    WM Converter - another easy to use video converter. Converts from almost any format to almost any other format. You can also convert multiple files in the same session, so you can "set it and forget it" (sorry Ronco).


    Free Video Converter = MPEG Converter + AVI Converter + FLV Converter + YouTube Video Converter + MP4 Converter
    Any Video Converter - simple, easy to use, powerful video conversion.This one can also clip, sort, and merge video clips to create a new movie and can also crop the frame. This has saved me a few times when other converters just wouldn't convert a file. It also can convert with better quality many times.


    All of these are great options if you need to convert video files.
    READ MORE - Free Video Format Conversion Software (3 of them)

    VLC - Awesome free video and audio player (and converter)



    Video is an important part of life and education. We use videos in class for a variety of reasons. Videos come in many different formats too. It's no fun to need to have 3 or 4 different video players (Windows Media Player, Real, Quicktime) to play them all. While most of them can play formats that others can, I've run into problems with all of them. Some videos won't play on them at all, and others are lower quality. Solution: VLC Multimedia Player.




    Large Orange VLC media player Traffic Cone Logo


    VLC Multimedia Player is a free, open-source, video and audio player that plays most multimedia files as well as DVD, Audio CD, VCD, and various streaming protocols. 


    VLC Multimedia Player is easy to use and starts up quickly.  It can play video and audio files, DVD, CD and VCD and can play streaming video. It rarely needs any additional downloads to play most videos. 


    You can also use it to convert video and audio files to other formats (especially handy for converting certain formats to be able to upload them to a website or use on a mobile device).


    VLC Multimedia Player is free, easy to use, and very powerful.  It is available for Windows, 10 different versions of Linux, Mac, iOS,  and Unix. 


    Screenshot on my system.


    You can see more screenshots here.





    READ MORE - VLC - Awesome free video and audio player (and converter)

    End of the school year approaches - lesson ideas and reflection



    We are quickly approaching the end of the school year. Advanced Placement Exams start next week, effectively the end of AP classes (although I do a lot of projects with my AP students after their exam). The student's last day of school is June 21st and teachers finish on June 22nd. Seniors will be finished by June13th though as they then have graduation rehearsals and Senior activities. I teach 90% seniors, so I have to finish up everything by the 1st of June when Senior finals begin. 


    As I was looking over the schedule and working on my lesson plans for next month, I was trying to decide what I would do with my students. I use web quests, videos and activities from Discovery Education, and projects to keep my students learning during a time of distraction. Senior Prom, Junior Ring Dance, end of the year, Spring Fever, Senioritis. They all affect schools around this time. So, I use the projects. Think of projects related to your curriculum that would be great to do at the end of the year and use that instead of lectures, problem sets, or standard labs.

    The rockets project is my favorite and my students favorite. The web quest incorporates elements from NASA's web site. The students are applying multiple areas of physics during this project: energy, chemical reactions, fluid dynamics, forces, Newton's Laws, and more. They get to work in a group and do something hands-on and creative (they get to decorate the rockets any way they want and they are also able to do different fin designs). The best part is launch day. The students get to go outside and launch rockets. I handle the actual launching so that I can ensure safety, but the students love the countdown and watching the launch. They also have to chase down rockets that drift in the wind. Who wouldn't want to be outside launching rockets on a beautiful Spring day?. Then, they do a web quest on aerodynamics and then design, build, and fly their own gliders. They learn some great physics topics while having a lot of fun.





    Another thing I start doing around this time is to reflect on the past year. What worked? What went right? What went wrong? How did I handle classroom management issues? How well did my students learn? Lots of questions to answer and get ready for next year. I do this throughout the year too, but this is the point where I can really plan and make changes for the following year.

        




    One thing I do to as an evaluation of the year is to have my students fill out a survey about the class and their experience. It asks them to rate things such as was the classroom and equipment (labs and projects) adequate, was enough time given for demonstrations and review, how well did the teacher answer student questions, and their thoughts on assignments and work given. It also asks about me: did I set a climate that was conducive to learning, did I effectively communicate with students, did I address their needs and issues, and were the teaching methods effective. I also have space for them to write comments about what they liked about the class and what they think should be improved. They can put their name on it or it can be anonymous.


    I do take the surveys with a grain of salt. Some students write all "4" (highest score) and some complain that everything was too hard. But I do get a lot of great feedback and ideas. Some times I am surprised by the level of sophistication that I my students have and how insightful they are about their classes. (I've also used this model with pre-service teachers).

    After I've read through all of the surveys and taken notes, I sit and think about the whole year. I try to be critical of things so that I can really evaluate how things went. I am going to implement some of the things I've come up with and some of the things my students noted, but I am also going to keep my lessons flexible so that I can modify them once I've met my students next year and see what they are like and what they need. I believe in constantly assessing how I am doing as an educator and how well my students are learning and changing and modifying things as needed throughout the year. The end of the year and summer are great times to come up with lots of different ideas so that I have a collection of ideas to use next year.

    Ongoing Assessment is a term we use in EMS for constantly monitoring our patient and changing our treatment as needed based on the patient. This is also something we do in education. We change things to meet the needs of our students.

    This year I've been using the classroom blogs and Google Forms to get more feedback from the students throughout the year. I will also be using a Google Form instead of paper for this year's final class evaluation. 

    As I write this, I keep having thoughts about issues I've had and how to change them next year. I'm also thinking about the type of teacher I am and what I can do to improve my attitude and persona to make me better. I think one of the things I'm going to do this summer is to actually relax a bit instead of working to much to recharge myself. I will be attending a few conferences and will keep active with my PLN (Personal Learning Network) to share ideas, thoughts, and resources. I want to come back to school next year enthusiastic, motivated, and ready to have some fun while educating. 


    So, let's hear from you:

    What do you do in your classroom at the end of the year to keep students focused and engaged?

    How do you evaluate teaching and learning in your classroom? 

    What do you do at the end of the year and summer to prep for the next year?



    READ MORE - End of the school year approaches - lesson ideas and reflection

    Empty Lot(s) of the Week-- April 28

    The CCCC Tunnel Mega-Lot

    From the Corner of N. 9th and Filbert going north through the middle of the 800 blocks of Arch, Cherry, Race, and Vine Streets.


    So big only an aerial view can show it all. Holy shit.
                  This is one gigantic motherfucker of a lot. It spans entire blocks and continues across the street. It's the Center City Commuter Connection Tunnel Mega-lot. Many modern Philadelphians know very little about the Centery City Commuter Connection even though it was in the center of Philly politics and redevelopment from the 1950's to the 1980's.
                   Long story short: Badass Motherfucker Pro Tempore Richardson Dilworth, whose mayoral administration effects every Philadelphian living today, was sick and tired of having to use two different train lines from one side of the city to the other. His ho's were especially angry. He proposed a train tunnel that would connect the two underground. The city said "fuck you" because it would cost too much money. The train companies said "fuck you" because they hated each other and didn't have trains capable of traveling through the tunnel. The Federal Government said "fuck you" about trying to help fund it. Dilworth and the mayors that succeeded him were fucked....
                 Until the Five-Star Admiral of Badass Motherfuckers came along... Mayor Frank Rizzo. He said "eat shit" to every other kind of transit improvement and convinced the Federal Government and the state to throw funding at the project by giving everyone involved one gigantic collective headlock. Construction was an ongoing mess of blocked traffic and pissed off pedestrians for six years.
                 Extreme care was taken when constructing the tunnel under the Masonic Temple, City Hall Annex, Reading Terminal, and Strawbridges' Building. The Aramark Tower and shitty-ass Gallery were under construction at the time so constructing the tunnel through them was easy. Then it needed to turn north to connect to the track the Reading Viaduct used to come from. After all that effort to buttress under those buildings, the construction got to Chinatown and they just said, "Forget it, Jake. It's Chinatown. Mow it all down motherfucker!", and they did. The result was a 4 block long hole that later got covered with surface lots. Check the picture above. The buildings outline the path of the CCCC.
                  Fast Forward 27 years. Twenty-seven goddamn years and you still have an empty lot that extends for blocks. I used to think that no buildings were built over the CCCC due to noise, weight, and vibration concerns... until I found out that the deepest part of the track is in that area AND that the track was designed to be sound and vibration proof... SO WHAT FUCKIN' EXCUSE DO WE HAVE? There should be 20 buildings in the regions that this lot extends! That ugly-ass Pearl Condo box was built as an attempt to slightly un-fucktify this mega-lot but there needs to be more. This makes me soooo angry. FUUUUUUUUUUUUUUUUUUUUUUUUUuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuu......
          
    READ MORE - Empty Lot(s) of the Week-- April 28

    Why Didn't Astrive or Monticello Tell you This About your Student Loan!

    Right now, college-bound students in Florida (where I live) and across the country are getting bombarded with ads for student loans from companies such as Monticello and Astrive: "$40,000 in Two Days!" "Better Rates if Your Parents Co-Sign!"







    This coincides, of course, with college acceptances. Many parents and students are opening letters telling them they've been admitted to the college of their choice, only to have that brief elation met with the harsh reality of having no clue about how the heck they're going to afford college.







    One such option is applying for financial aid. Unfortunately, the "rules of the game" behind how to maximize the money you're eligible for are complicated, to say the least. Most families (78-90% , according to some industry estimates) fill out the FAFSA and other forms incorrectly. This results in the student receiving less aid than he or she would have normally qualified for, or, sometimes, no aid at all.







    All too often, the student turns to alternative means of college funding: private student loans. However, you need to think twice if you're planning on financing your college education this way.







    Before you sign your life away, take a deep breath and consider what you might be getting yourself into.







    Most parents and college-bound students do not realize that student borrowers are not-so-distant cousins to headline-making borrowers with subprime mortgages. Many experts, present company included, believe that the student loan market is poised to experience the devastation currently affecting the subprime mortgage industry.







    To be sure, when I rant about the similarities between subprime, predatory lending and student loans, I'm not exactly the most fun at parties. I am and, let me tell you, the similarities are alarming.







    For starters, student borrowers and subprime mortgage holders are ill-advised on financial matters (present company excluded, of course) - specifically, the consequences of their borrowing decisions.







    It is not exactly news that that adjustable-rate mortgages (ARMs) resetting to high interest rates are the main culprit behind late payments, defaults, foreclosures and ruined credit.







    Here's how it works - mortgage companies offer low teaser rates to get homeowners in the door, but frequently, the initial required payments are not even enough to pay the interest on the loans. It gets worse.







    Then, after the ARM "resets," homeowners are stuck with payment increases and are faced with the unpleasant and costly alternative of refinancing. This worked for years, because it was relatively easy to qualify for new mortgages, but this rosy scenario screeched to a halt simultaneously with the collapse of the secondary mortgage market, slumping real estate values and a slowing economy.







    The result: subprime borrowers were denied credit, were forced to stay in their unpayable loans and pushed into default or, unfortunately, foreclosure. Right here in Florida and across the country, college graduates burdened by student loans face similar problems. Just like the mortgage companies, student lenders offer a low teaser rate which adjusts upward (it's almost always up, not down, unfortunately!) after the introductory period.







    Next comes the inevitable late payments, non-payments, defaults and ensuing credit problems. It's a slippery slope! The result - payments get jacked up a few years after the loan originated. And the new spiked payment almost always catches the borrower by surprise. Just like their subprime borrower counterparts, student loan holders are unable to make payments once the loan adjusts upward.







    In most cases borrowers of both student loans and subprime mortgages claim that they were misled about the terms of their loans. They cry that the lenders withheld vital information, or glossed over important information.







    The good news is that Congress has begun calling for increased regulation and disclosure in the student lending industry.







    Don't hold your breath, however. This could take years. Your best bet to protect yourself is using your own brain - asking the right questions, listening to the answers. "What is the interest rate?" "When can the loan adjust, if at all?" "If I cannot make a scheduled payment, what is the consequence?"?"







    To be fair, many student lenders offer this information voluntarily, which helps borrowers make better choices. But this is the exception, not the rule.







    Another favorable trend is that many colleges and universities have become more proactive and supportive in educating students about all the details surrounding student loans. Many schools have made available a "borrowing consultation" offered by their financial aid advisor. And in some instances, particularly among the elite higher education institutions, the financial aid packages feature little or even no loans, opting instead for "free" money awards - scholarships and grants. The top schools, such as Harvard, Princeton and Yale, are leaders in this area.







    It's clear that there is no easy solution for this problem. However, it's imperative to be mindful of the example set by the subprime mortgage meltdown, and avoid the consequences that accompany irresponsible and borrowing and lending.







    College Pete and I are extremely debt-adverse and strongly urge you to do anything possible to minimize, or flat-out eliminate, borrowing for college. Think twice before you sign for that loan!
    READ MORE - Why Didn't Astrive or Monticello Tell you This About your Student Loan!

    Google Accessibility - resources to make Google products accessible to those with disabilities


    Google Accessibility is Google's site that explains the accessibility resources that Google has for both users and developers and publishers.

    There is a whole section on using the accessibility features for many Google products. Android Phones, Chrome Browser, Gmail, Docs, eBooks, Maps, Search, and more all have accessibility functions to help people with disabilities to use these products. There are keyboard shortcuts, video captions, high contrast video, text-to-speech and speech-to-text, and much more.

    These features help all users, including people with blindness, visual impairment, color deficiency, deafness or hearing loss, and even limited dexterity use Google's products and access information on the web.

    Teachers with students with impairments should explore these resources and help their students use them.
    READ MORE - Google Accessibility - resources to make Google products accessible to those with disabilities

    Ways to Deal With the Disastrous Consequences of Defaulted Student Loan

    Student loans are good aid for several students who are incapable to pay their college or tuition fees. These effective assistance can turn out to be a burden in future specially once the student completes his/her graduation and get job. The consequences can worse once the former student forgets to pay off the loan or becomes defaulter for any other reasons. This defaulted student loan is a type of loan that is not going to vanish even after several years. As the student is availing the money from an institution approved by the state, the loan provider will maintain the records of the defaulted loans.
    To wipe out these records of defaulted loans it is necessary for the individuals to talk to their tuition officer of their former college. From these tuition officers the students will be well informed about the amount of outstanding money. Moreover the students will be capable to discuss about the methods of repayment that can assist them to pay off the entire defaulted student loan easily.
    It is essential for the students to disclose their present capability of payment. This is essential as students will require it to conclude at the agreement regarding the repayment amount. This amount will be paid by the student as installments for his/her defaulted student loan. Once the student has received the entire detail about the total repayment amount. This will assist him/her in calculating the time span he/she will require to pay it off in full. While getting these student loans are easy and assisting, the students will come across several terrible consequences due to their defaulted loans.
    The loan providers will look at the defaulted student loan in various ways. The outlook of these loan providers changes depending on educational institution from where the students has done his/her graduations. The government has given different ways also for the students to come out of this difficulty of defaulted student loan. This helps several students to pay off the loan in an easier way. Otherwise the agency for student's loan collection will be contacted by the college or university. These collection agencies are specially authorized organizations to collect the outstanding loan money.
    Previously the institutions or loan providers could sue any student who were not paying off their loans and had huge amount of defaulted student loan. In these situations, the students needed to appear in court numerous times as a result of evading their responsibilities. These are only a few of several terrible consequences that the students had to face as the result of having defaulted loans. If any student discovers himself/herself getting into terrible financial difficulties, he/she should discuss their repayment choices with loan officer in their institution. For several of the students these loans are an effective way of relaxing the stress and meeting the expenses of the education. Once the students have finished with their course of study, it will be better for them to start making repayments on their student loans. You can easily avoid these disastrous consequences simply by repaying this loan in the correct time.
    READ MORE - Ways to Deal With the Disastrous Consequences of Defaulted Student Loan

    If I were a curriculum or edtech administrator, I would...







    Recently, Teach Paperless had a blog post asking readers to finish the statement, "If I were an administrator, I would...". 


    I replied with "encourage teacher collaboration, support teachers in every way possible, encourage projects and team work, visit classrooms and talk to students, work WITH the faculty, parents and students to make the school the best it could be."


    I wanted to expand on this idea and list what I would do if I were in charge of curriculum or educational technology for my district.


    1. Implement Project Based Learning throughout the curriculum and in every grade. I would also want it to be interdisciplinary. 


    2. Change the curriculum to be more in depth, and less breadth of topics (complaint of colleges). I would still have to make sure students are prepped for standardized testing (unfortunately), but I would look at better ways of having students learn and be able to do well on a test without resorting to teaching to the test.


    3. Make sure the curriculum applies what students are learning to the real world. They won't remember a lot of facts and details, but if things apply to real life, it can make them better consumers and better citizens (by being knowledgeable). 


    4. The curriculum should emphasize discovery, inquiry, teamwork, critical thinking, and problem solving, not remembering tons of facts. 


    5. Ala Carte Professional Development for teachers - let them pick and decide what they need and want for training and support them throughout the year. 


    6. Research, find, implement, and support new technologies that can improve teaching and learning. Find free (or cheaper) resources to replace paid or more expensive resources. (Ex. Google Apps for Education and Open Office instead of Microsoft).


    7. Provide year-round support to teachers who are using and implementing technology resources. Make sure that they have both technical support and integration support. Ask teachers what they need or want for resources and help them find it. 


    This is my short list of what I would want to do as an administrator. What would you do if you were in charge of curriculum or educational technology for your district? (and if you are in charge, what you do?)



    READ MORE - If I were a curriculum or edtech administrator, I would...

    Flipped Classroom - what it is and my reservations of it

    "Flipped Classroom" is a relatively new idea, where the teacher works with students on projects and what would be typically homework instead of a lecture and the students get the "lecture" at home, usually through a video (like from Kahn Academy). The proponents of this model say that it offers the teacher more time to work with students on projects and applying the knowledge, rather than spending time delivering that knowledge.

    I have some issues with the "Flipped Classroom" model. The first is that this model leads to a lot of homework for students if they have to watch videos of lectures. This is not only asking a lot of the students to be able to do, but not anything really new or inventive. Students have other obligations and time commitments and watching video lectures is time consuming.

    Students may not have access to a computer at home with high speed internet (needed to watch these videos). Many of my students do not have a computer at home, or have a dial up network. Many do not have anywhere quiet to work or listen to these video lectures.

    While watching a video lecture, a student has no one to ask questions of. They would have to write down the question and then ask their teacher the next day. This may cause students to get confused early on and just shut off the video. It is very passive - there is no interaction and no discussion with others. This not how we want our students to learn.

    I do share video sites with my students so that they can use them as a review or reference (or even different delivery style and explanation). But, it's not required of them. There are some great online videos available for students to use to learn material, but I don't think it should be the primary delivery method for them.

    I use "lecture" of a sort in my Physics class. I use PowerPoint, Prezi, animations, demonstrations, and discussions to present material, ideas, content, and such with my students. They can ask questions of me. We can discuss the topic and it's applications. I also show them short videos in class and pause it at different points to answer questions or discuss what's going on with them. The "lectures" are short and give the basic information for a topic. The students then explore the topics in more depth using projects, labs, and virtual investigations and simulations. They get packets for each topic with a summary of the topic and problems (these packets are much better than the textbook). They start these problems in class and then finish them for homework. We go over the problems in class after they complete them. I have a class website and blogs for each class with links and other resources. For students that don't have computer access at home, I share different printed resources with them.

    In my AP Physics class, I have to modify things a little. I present the content for each topic via a PowerPoint presentation and we discuss the topics. The students also have a textbook to read, problems to do, and they do projects and labs. These students typically have much more access to computers at home and are more independent learners. I cover the main points in class and they explore the rest on their own. There are some great online lecture videos for AP Physics that they can use for review or reinforcement, but again, they are not required.


    The "Flipped Classroom" may work in some schools and with some students, but it is not a good fit for many students and should be used cautiously.
    READ MORE - Flipped Classroom - what it is and my reservations of it

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