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06/14/2015 12:00 AM

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General Discussion

13734 threads, 246264 comments (13 Viewing)

Comet Sinkholes

07/01/2015 by Fredski
It's now thought our favorite comet has numerous craters that are not from impacts as much as from sinkhole activity
Views: 47, Comments: 3
Last comment 07/02/2015 by Rixter


06/30/2015 by Fredski
hail can be rough on the paint job! check out this Delta bird
Views: 203, Comments: 14
Last comment 07/02/2015 by ignator

The Leap Second Is Coming!

06/30/2015 by SplicedWire
Days are actually getting longer and we finally have more time to accomplish items on that to-do list. Well actually we will only be getting one secon...
Pathfinder Tags: Earth rotation leap second NASA time
Views: 174, Comments: 14
Last comment 07/02/2015 by PWSlack

What is the Impact of Supply Frequency on Stepper Motors?

06/30/2015 by simonsd
I am looking to bring a device (ok its a cat toilet) from the UK to Korea (RoK). The suppliers are not willing to supply because Korean electricity ru...
Views: 262, Comments: 33
Last comment 07/02/2015 by Original_Macgyver

Opposite Worlds

06/29/2015 by jdretired
Further speculation? One reads about there being an opposite universe? Giving this some thought, I've come up with the following speculation. NORMAL...
Views: 156, Comments: 9
Last comment 07/01/2015 by Anonymous Hero
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Commercial Space

1864 threads, 3503 comments (0 Viewing)

Civil Engineers

07/02/2015 by vietnam manpower
VMST is one of leading construction recruitment agencies from Vietnam specializes in supplying high-qualified construction manpower at management leve...
Pathfinder Tags: civil engineers engineering Vietnamese engineers
Views: 22, Comments: 0

The Features and Applications of Melamine Foam

07/02/2015 by asianglorychem
Melamine foam is a new type of high opening role rate 3-D grid structure foam. As a kind of low density, flame retarding, sound-absorbing material, it...
Pathfinder Tags: Melamine Foam Melamine Foam Resin Melamine Sponge Sound Absorbing Materials
Views: 21, Comments: 1
Last comment 07/02/2015 by PWSlack

Tips for Maintaining your Roof

07/01/2015 by Marielle Holmes
Repairing a roof can be an expensive project, but if you know which signs to look for in order to keep your roof maintained you can get more life out...
Views: 23, Comments: 1
Last comment 07/01/2015 by lyn

CNC Hydrualic Die Forging Hammer

06/29/2015 by 18625862110
Introduction of CNC Hydraulic Die Forging Hammer: CNC Hydraulic Die Forging Hammer are widely applide in automobile forgings, motorcycle forgings, ha...
Pathfinder Tags: cnc hydraulic die forging hamnmer die hydraulic forging hammer
Views: 16, Comments: 0

Universal Level Sensor

06/25/2015 by Ashutosh Kumar
We have developed an innovative Universal Level Sensor that is non-contact type, digital display, unlimited depth measurement, for any medium applicat...
Views: 43, Comments: 1
Last comment 06/25/2015 by texasron
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CR4 Feedback

631 threads, 11218 comments (0 Viewing)

Who Is Online Link Not Working

06/28/2015 by IdeaSmith
The "Who is online" link not working. Hope this will be fixed soon.
Views: 62, Comments: 2
Last comment 06/29/2015 by IdeaSmith

Incorrect Score for Good Answers?

06/24/2015 by dhayanandhan
TO: CR4 ADMN This posting is NOT WITH AN INTENTION of FAULT FINDING or BLAMING ANYBODY or THE SYSTEM. I have replied a thread on 22nd June 2015 and...
Views: 671, Comments: 67
Last comment 07/01/2015 by tonyhemet

Smaller Text in CR4

06/23/2015 by dkwarner
Did the text size just get dramatically smaller in CR4, or did something happen in my computer? The text suddenly got smaller a few days ago. Now I c...
Views: 377, Comments: 35
Last comment 06/29/2015 by phoenix911


06/21/2015 by JohnDG
Yikes. All I did was click "Who's Online". What's occurring?
Views: 87, Comments: 4
Last comment 06/22/2015 by lyn

Breakfast with CR4

06/20/2015 by gringogreg
I love weekend mornings with CR4. Always a generous serving of fresh spam, YUM The CR4 administrators do a very good job of weeding this junk out, bu...
Views: 312, Comments: 37
Last comment 06/24/2015 by lyn
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Section Blogs

Roger's Equations

137 blog entries, 1567 comments (4 Viewing)

Does Pluto Have a Giant Crater?

07/01/2015 by Roger Pink
New Horizons It's an exciting time for space enthusiasts. The NASA probe, New Horizons, is just two weeks from its July 14th flyby of Pluto. Everyday...
Views: 149, Comments: 4
Last comment 07/02/2015 by Hilton

June 30th and July 1st - Venus and Jupiter Conjunction

06/30/2015 by Roger Pink
The Two Brightest "Wanderers" Meet The last several weeks, the two brightest planets in the night sky, Venus and Jupiter, have been inching closer to...
Views: 155, Comments: 1
Last comment 07/01/2015 by Roger Pink

Population III Stars

06/28/2015 by Roger Pink
Stars of the Early Universe Scientists believe that the first generation of stars that formed after the big bang were likely very large, very hot, an...
Views: 132, Comments: 2
Last comment 06/30/2015 by facilitiesmgr
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Defense & Security Technology

87 blog entries, 1395 comments (0 Viewing)

F-35 Block Buy Could Cut Costs

06/28/2015 by IHS Engineering360 eNewsletter
Buying up to 450 F-35s in a three-year block buy could yield "double-digit" cost savings, according to Frank Kendall, U.S. undersecretary of defense f...
Views: 157, Comments: 21
Last comment 07/01/2015 by phoenix911

Tonight There's Gonna Be A Jailbreak

06/17/2015 by HUSH
By now you've probably heard the truth-is-stranger-than-fiction story of the prison escape in upstate New York. Presumably like many other non-jaile...
Pathfinder Tags: design escape prison tunnel
Views: 303, Comments: 5
Last comment 06/27/2015 by Wal

Russia May Deal "Blackjack" Production Again

05/30/2015 by IHS Engineering360 eNewsletter
Russia is studying whether or not to restart Tu-160 (NATO code-named "Blackjack") strategic bomber production. In visiting the plant where the aircraf...
Views: 279, Comments: 4
Last comment 06/01/2015 by Gavilan
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What Is It?

63 blog entries, 1722 comments (0 Viewing)

What is It? for June 28

06/28/2015 What is it? Share your guess in the comments below! Thanks to CR4 member Dan A for sharing this image.
Pathfinder Tags: what is it
Views: 488, Comments: 34
Last comment 07/02/2015 by bob c

What is It? for June 21

06/21/2015 What is it? Share your guess in the comments below! Thanks to CR4 member Dan A for sharing this image.
Pathfinder Tags: what is it
Views: 569, Comments: 52
Last comment 07/02/2015 by Dan A

What is It? for March 12, 2015

03/12/2015 What is this? This image was submitted by JIMRAT. Please feel free to submit your own images for future use on this blog.
Pathfinder Tags: what is it
Views: 549, Comments: 4
Last comment 03/20/2015 by James Stewart
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Caption This!

313 blog entries, 13553 comments (2 Viewing)

Caption this for 07/03/15

07/02/2015 by LakeGrl
This weeks image: Be sure to vote for your favorite caption! Thanks to Nigh for submitting this image.
Pathfinder Tags: engineering engineering images funny images overpass Trucks ...
Views: 8, Comments: 0

Caption this for 06/26/15

06/25/2015 by LakeGrl
This weeks image: Be sure to vote for your favorite caption!
Pathfinder Tags: engineering engineering images funny images rail Tracks
Views: 712, Comments: 84
Last comment 07/02/2015 by Unredundant

Caption this for 06/19/15

06/18/2015 by LakeGrl
This weeks image: Be sure to vote for your favorite caption! Thanks to Unredundant for submitting this image.
Views: 548, Comments: 36
Last comment 06/24/2015 by James Stewart
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Notes & Lines

21 blog entries, 139 comments (0 Viewing)

Your Kitchen Table Is Now A Musical Instrument

06/25/2015 by Jonathan Fuller
Pocket-sized instruments have always appealed to musicians. Pulling out a harmonica, xaphoon, or ocarina and playing on the go seems like the pinna...
Pathfinder Tags: electronic music tonetree
Views: 218, Comments: 5
Last comment 06/30/2015 by IanR

RIP Grooveshark

05/11/2015 by Jonathan Fuller
Many people of a certain age (mine, specifically) will likely tell tales about the brief Golden Age of Napster to their children and grandchildren....
Pathfinder Tags: dcma digital copyright grooveshark P2P
Views: 194, Comments: 2
Last comment 05/13/2015 by tcmtech

Vinyl: No Longer Just for Audiophiles?

03/12/2015 by Jonathan Fuller
Music biz writers scrambled to their blogs in January 2015, when Nielsen SoundScan announced that 2014 vinyl sales had come in at 9.2 million units...
Pathfinder Tags: analog recording audio vinyl records
Views: 241, Comments: 14
Last comment 05/13/2015 by Original_Macgyver
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Animal Science

215 blog entries, 1972 comments (0 Viewing)

Analysis of a Champion: American Pharoah

06/09/2015 by SavvyExacta
American Pharoah has won the Triple Crown! This headline has been shouted at us since he became the first horse in 37 years to accomplish the feat....
Pathfinder Tags: horse racing
Views: 162, Comments: 5
Last comment 06/09/2015 by JBTardis

Brontosaurus vs Apatosaurus

04/24/2015 by Chelsey H
When I was little one of my favorite movies was "We're Back: A Dinosaur Story". It's a ridiculous cartoon about dinosaurs showing up in a big city....
Views: 233, Comments: 1
Last comment 04/24/2015 by SavvyExacta

A Fishy Mystery

03/24/2015 by Chelsey H
So admittedly I have never thought of this before, but do fish get out of breath? Fish rely on their gills to remove oxygen from the water. Gills ar...
Views: 370, Comments: 9
Last comment 03/26/2015 by truth is not a compromise
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The Engineer's Notebook

339 blog entries, 5440 comments (0 Viewing)

Speaking of Social Robots...

06/18/2015 by Jonathan Fuller
The fact that we humans have a predilection for sociable robots is pretty well mirrored in our science fiction creations. Rosie's smart-aleck commen...
Pathfinder Tags: paro pepper social robots therapy robots
Views: 166, Comments: 4
Last comment 06/27/2015 by Wal

The Hyperloop Lives

06/09/2015 by HUSH
If you ever compose a blog for CR4, prepare to be told you're wrong. It has happened to me dozens of times and it's somewhat of an 'earned stripe.'...
Pathfinder Tags: atmospheric railway Elon Musk future hyperloop
Views: 234, Comments: 6
Last comment 06/11/2015 by Rixter

Golf Courses: Less Green is Greener

06/08/2015 by BestInShow
Do golf courses eat up more than their share of scarce resources, especially water? Of the approximately 35,000 golf courses worldwide, fewer than...
Views: 170, Comments: 3
Last comment 06/10/2015 by lyn
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Challenge Questions

329 blog entries, 27624 comments (1 Viewing)

Apollo 11 Communications Log- Gimbal Lock: Newsletter Challenge (July 2015)

07/01/2015 This month's Challenge Question: Specs & Techs from IHS Engineering360: CapCom - "Columbia, Houston. We noticed you are maneuvering very close t...
Pathfinder Tags: challenge questions NASA
Views: 249, Comments: 7
Last comment 07/02/2015 by Andy Germany

Airbag Physics: Newsletter Challenge (June 2015)

06/01/2015 This month's Challenge Question: Specs & Techs from IHS Engineering360: This month we had the largest automotive recall in U.S. history: 33.8 mi...
Pathfinder Tags: challenge question
Views: 1693, Comments: 27
Last comment 06/06/2015 by WilhelmHKoen

Styrofoam Slide (May 2015)

05/01/2015 This month's Challenge Question: Specs & Techs from IHS Engineering360: Try this experiment: slide a Styrofoam cup full of water across a smooth...
Pathfinder Tags: challenge question
Views: 1970, Comments: 49
Last comment 06/27/2015 by WilhelmHKoen
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The CR4 Admin Blog

76 blog entries, 1309 comments (0 Viewing)

What Do You Want to Read About?

05/21/2015 IHS will soon be featuring sponsored blog posts from suppliers on CR4. Don't worry! CR4 won't be overrun with sponsored content. There will be a max...
Views: 201, Comments: 15
Last comment 05/25/2015 by Yahlasit

The Homework Question Debate

04/22/2015 We've all seen them... posts that are obviously homework questions copied directly from students' textbooks. It's understandable that nobody should ge...
Views: 481, Comments: 46
Last comment 05/01/2015 by James Stewart

100,000th Thread Posted to CR4

04/02/2015 CR4 has reached another milestone! About one year ago the millionth comment was posted to CR4. Just last month the 100,000^th thread was posted. Th...
Views: 244, Comments: 14
Last comment 04/07/2015 by JIMRAT
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Editor's Desk

12 blog entries, 65 comments (0 Viewing)

A Cultural Icon Turns 35

05/19/2015 by wagman262
Our infographic for the week of 18 May looks at the impact of Pac-Man on video games 35 years after its release in Japan. From an engineering design p...
Views: 107, Comments: 0

Hardening the Energy Coast

04/30/2015 by wagman262
As part of our ongoing look at risk mitigation and engineering, Engineering360 published this terrific article that examines infrastructure hardening...
Views: 116, Comments: 2
Last comment 04/30/2015 by SavvyExacta

Moore's Law at 50

04/16/2015 by wagman262
Bill Schweber, one of our contributing editors, has a terrific piece on the 50th anniversary of Moore's Law. Have a look at it here and let me know wh...
Views: 246, Comments: 10
Last comment 04/23/2015 by Wal
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Relativity and Cosmology

144 blog entries, 3757 comments (1 Viewing)

How Zeons turned into something Useful

06/30/2015 by Jorrie
In the last Blog, How Aeons turned into Zeons, we derived a very simple formula for the expansion dynamics of the cosmos: (5) H^2 = 1 + 0.443 S^3 wh...
Views: 67, Comments: 0

How Aeons turned into Zeons

05/12/2015 by Jorrie
Quite a lot has been written on this CR4 Blog about the standard Lambda-Cold-Dark Matter (LCDM) cosmological model and its equations. Arguably the...
Pathfinder Tags: cosmological constant cosmology expansion
Views: 214, Comments: 0

HTRN's Cosmology Questions

01/17/2015 by Jorrie
in HTRN's thread about the rate of bubble rise and expansion in a fluid, he also saw analogies to cosmological expansion and he speculated: "Maybe we...
Pathfinder Tags: cosmological constant cosmology expansion
Views: 346, Comments: 16
Last comment 02/10/2015 by HiTekRedNek
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62 blog entries, 523 comments (0 Viewing)

Big Bets Lost on Vegas Hotel

04/23/2015 by HUSH
If you're in Las Vegas, you're probably going to gamble. The city is well known for its attractions, from the resorts to the shopping to the shows t...
Pathfinder Tags: architecture las vegas structural engineering
Views: 285, Comments: 2
Last comment 04/25/2015 by Rixter

Safety Concerns of Oil by Rail

10/30/2014 by cheme_wordsmithy
Historically, most oil in the U.S. has been transported via pipeline. In 2008, the U.S. saw the rise of a new alternative for crude oil shipment - rai...
Views: 451, Comments: 19
Last comment 02/23/2015 by machia0705
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Rockaholic Adventures

45 blog entries, 573 comments (0 Viewing)

Independent Party on Disappointment Cleaver – Part II

02/17/2015 by Shawn
The historic ratio of independent parties to guided ascents of Mt. Rainier holds steady at roughly 45% to 55%. In search of a true sense of accompl...
Pathfinder Tags: Disappointment Cleaver Mt. Rainier
Views: 166, Comments: 0

Independent Party on Disappointment Cleaver - Part I

02/06/2015 by Shawn
Mt. Rainier via Disappointment Cleaver is a formidable expedition on glaciated terrain for novice mountaineers. It is a challenging class III climb...
Pathfinder Tags: Disappointment Cleaver Mt. Rainier
Views: 144, Comments: 2
Last comment 02/09/2015 by Shawn

Are Energized Fluids the Economic Alternative?

10/03/2014 by Shawn
Suppliers, researchers, and service companies working in unconventional oil and natural gas plays look to displace large volumes of hydraulic fract...
Pathfinder Tags: energized fluids energized foams energized fracture treatments
Views: 316, Comments: 0
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The Standard

4 blog entries, 13 comments (0 Viewing)

New ISO Energy Management Standard Released

11/18/2014 by KevinCassidy
The International Organization for Standardization (ISO) has released the new ISO 50003:2014 Energy management systems - Requirements for bodies provi...
Pathfinder Tags: ANSI audit certification Energy energy standards ...
Views: 214, Comments: 0

Follow up: Women's Lacrosse Headgear Standard Set for Second Ballot

11/13/2014 by KevinCassidy
I wrote about the debate between the Florida High School Athletic Association and US Lacrosse over the use of helmets during high school girls lacross...
Pathfinder Tags: ANSI ASTM eye protection face florida ...
Views: 137, Comments: 1
Last comment 01/28/2015 by sporteyes

Don't Forget to "Look Before You Pump"

11/05/2014 by KevinCassidy
The Outdoor Power Equipment Institute (OPEI) has been active in educating consumers about the variety of fuels available at the pump, and how to ident...
Pathfinder Tags: ANSI automotive E10 E15 equipment ...
Views: 232, Comments: 8
Last comment 11/08/2014 by tcmtech
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Physics In Film

9 blog entries, 85 comments (0 Viewing)

Medieval Physics - Siege Engines

09/03/2014 by cheme_wordsmithy
I don't think a blog series titled Medieval Physics would be complete without a discussion of siege engines. Siege engines were the machines that made...
Views: 700, Comments: 10
Last comment 09/09/2014 by SavvyExacta

Medieval Physics - Jousting

08/26/2014 by cheme_wordsmithy
In a previous blog entry I gave a short summary of the physics and history of the bow and arrow (thanks to all you CR4 users who shared your insight a...
Views: 472, Comments: 8
Last comment 08/29/2014 by phoenix911

Medieval Physics - Bows & Arrows

08/12/2014 by cheme_wordsmithy
Of the many interesting events that take place in the summer, one of my favorites are Renaissance fairs. Seeing the participants in character and cost...
Views: 622, Comments: 15
Last comment 08/13/2014 by suresh sharma
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TechnoTourist’s Engineering Expeditions

80 blog entries, 461 comments (0 Viewing)

Vacation Destinations for Engineers

07/17/2014 by SavvyExacta
What are your summer vacation plans? TechnoTourist has compiled a list of some destinations of engineering interest that have been featured on the b...
Views: 703, Comments: 11
Last comment 07/22/2014 by SavvyExacta
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Other Blog Entries of Interest

Scrap Metal Wire Stripper

12/12/2014 posted in Workbench Creations
by frankd20
I have been working on a lot of building projects, with not much time for anything else these last few years. As part of these projects, I ended up...
Pathfinder Tags: copper wire recycling wire stripper
Views: 462, Comments: 8
Last comment 12/18/2014 by C-Mac

Slo' Mo' Hat Cam

07/04/2014 posted in Workbench Creations
by Del the cat
I wanted to see how my arrows were flying from my bow, specifically flight arrows. A flight arrow presents a conundrum, you'd think you would want...
Views: 857, Comments: 67
Last comment 07/15/2014 by europium mkII

Whistling Walnut!

12/28/2013 posted in Workbench Creations
by Del the cat
What to do with the walnut shells left over from Christmas? Make a whistling arrow . I'd been toying with the idea for ages, and if you try an...
Views: 958, Comments: 33
Last comment 01/02/2014 by artsmith

Detective Work On An Exploded Warbow

07/11/2013 posted in Workbench Creations
by Del the cat
It's often impossible to actually work out how and why a bow explodes. But this time I think I know! I was building a copy of a Mary Rose Warb...
Views: 1029, Comments: 13
Last comment 07/14/2013 by lyn

Del's Lathe Refurb' pt 3

06/20/2013 posted in Workbench Creations
by Del the cat
I've done the back gears, I could have bought new gears, but I thought I'd 'make do and mend'. I replaced the small cog with a slightly larger one...
Views: 780, Comments: 16
Last comment 06/22/2013 by Del the cat

Del's Lathe Refurb' pt 2

06/10/2013 posted in Workbench Creations
by Del the cat
The lathe came without any change wheels or the bracket to attach them, and one of the odd things about the lathe is the lead screw runs back to front...
Views: 614, Comments: 11
Last comment 06/25/2015 by Del the cat