Skip to content. | Skip to navigation

Personal tools
Log in
Sections
You are here: Home

jorgenmodin.net - Blog

Kompressionskläder för sport - en recension för social dans

Posted by admin |

Plagg som testats.

Användning

När jag dansar latinsk dans kan det bli väldigt varmt och svettigt, och man kan lokalt bli väldigt kall när man försöker svalka sig. Kompressionsplagg förbättrar cirkulationen nära huden och idén var att testa om kompressionskläder kan hjälpa mot lokal avkylning, samtidigt som de fortfarande håller en torr och sval.

Slutsats

Kompressionskläder fungerar, men vissa syntetmaterial såsom nylon suger åt sig vatten.

Detaljer

Jag har inte kunnat undgå att folk nu springer och går omkring i tights. Jag har motstått frestelsen av flera skäl, men insåg tidigare i veckan att kompressionskläder kan hjälpa mot lokal avkylning efter svettiga danser. Idealt sett ska de kläder man har på sig vara så fuktgenomsläppliga att man alltid håller sig torr och sval. I praktiken så blir man svettig och när man sedan kyler av sig så kan man lokalt bli väldigt kall, samtidgt som man fortfarande som helhet behöver mer avkylning.

Kanske kan kompressionskläder hålla uppe cirkulationen i dessa kalla delar? Då slipper man känna sig kall, samtidigt som man förbättrar kylningen av kroppen, genom att transportera varmt blod nära huden.

Kompressionshorts från Nike: "Cool Comp 6 Short" (90% polyester, 10% elastan). Dessa fungerar riktigt bra, och är hyfsat fuktgenomsläppliga. De kostar ungefär 200:-

Kompressions t-shirt från Under Armour "Zona" är en dyrare produkt, och jag valde att gå upp lite i pris för denna eftersom det var den kompressionströja jag såg minst löjlig ut i. Denna tröja innehåller mycket elastan (vilket jag antar drar upp priset) och har en ganska hög kompression, i alla fall jämfört med shortsen.

Efftekten under dansen  av tröjan var inte så väldigt bra: Den förhindrar visserligen lokal kyla med hjälp av kompressionen men den känns blöt och den tar tid att torka. Jag insåg varför, när jag efteråt noterade att den var gjord i nylon. Nylon är en stark och bra fiber, men den drar åt sig fukt, den är hydrofil. På Under Armour:s sida står det att det är polyester, inte nylon, men i lappen i själva tröjan står det nylon. Go figure. Jag är faktiskt inte säker på vad den är gjord av, längre.

Dagen efter var däremot effekten från tröjan bra, fast jag inte längre bar den. Det verkar som att kompression fungerar som en slags massage och ryggen kändes varm och med god blodcirkulation.

Min gissning är att ju mer elastan ett plagg innehåller, desto mer elastiskt blir det. Elastan är gissningsvis också dyrare än polyester eller nylon, så plagg med mycket elastan blir också dyrare. Vissa kompressionsplagg verkar gjorda för att användas under själva träningen och andra för att ha på sig efteråt.

Apr 30, 2017 05:40

Metalsmith - a blog site and general site generator

Posted by admin |

...that uses pipelines. I like pipelines. Metalsmith is in Node.js. But I also like Plone. And Plone has built-in commenting, that works ok.

 

Metalsmith

Apr 29, 2017 01:13

Initial ideas on how to get sshd into a Ubuntu server install

Posted by admin |

To add packages for the installation, add a %package section to the ks.cfg kickstart file, append to the end of ks.cfg file something like this.

%packages
@ ubuntu-server
openssh-server
ftp
build-essential

The above is from:

system installation - How do I create a completely unattended install of Ubuntu? - Ask Ubuntu

A skeleton kickstart file looks like this:

#
#Generic Kickstart template for Ubuntu
#Platform: x86 and x86-64
#

#System language
lang en_US

#Language modules to install
langsupport en_US

#System keyboard
keyboard us

#System mouse
mouse

#System timezone
timezone America/New_York

#Root password
rootpw --disabled

#Initial user (user with sudo capabilities) 
user ubuntu --fullname "Ubuntu User" --password root4me2

#Reboot after installation
reboot

#Use text mode install
text

#Install OS instead of upgrade
install

#Installation media
cdrom
#nfs --server=server.com --dir=/path/to/ubuntu/

#System bootloader configuration
bootloader --location=mbr 

#Clear the Master Boot Record
zerombr yes

#Partition clearing information
clearpart --all --initlabel 

#Basic disk partition
part / --fstype ext4 --size 1 --grow --asprimary 
part swap --size 1024 
part /boot --fstype ext4 --size 256 --asprimary 

#Advanced partition
#part /boot --fstype=ext4 --size=500 --asprimary
#part pv.aQcByA-UM0N-siuB-Y96L-rmd3-n6vz-NMo8Vr --grow --size=1
#volgroup vg_mygroup --pesize=4096 pv.aQcByA-UM0N-siuB-Y96L-rmd3-n6vz-NMo8Vr
#logvol / --fstype=ext4 --name=lv_root --vgname=vg_mygroup --grow --size=10240 --maxsize=20480
#logvol swap --name=lv_swap --vgname=vg_mygroup --grow --size=1024 --maxsize=8192

#System authorization infomation
auth  --useshadow  --enablemd5 

#Network information
network --bootproto=dhcp --device=eth0

#Firewall configuration
firewall --disabled --trust=eth0 --ssh 

#Do not configure the X Window System
skipx

Taken from here: 4.6. Automatic Installation

Apr 27, 2017 11:56

Enable mouse support in Emacs

Posted by admin |

Summary:

F10,  “Options” → “Customize Emacs” → “Options matching Regexp…”. Type mouse and Enter.

Go to “Xterm Mouse mode”.

Press Enter on “Show Value”. A “Toggle” button appears, press Enter on it. Then press Enter on the “State” box and choose  “1” for “Save for Future Sessions”

 

More complete info here: How can mouse support be enabled in terminal Emacs? - Unix & Linux Stack Exchange

 

 

 

Apr 26, 2017 08:18

sudo with no password on Ubuntu

Posted by admin |

In the /etc/sudoers file:

For a single user :

superuser ALL=(ALL) NOPASSWD:ALL

For a group :

%supergroup  ALL=(ALL) NOPASSWD:ALL

 

Apr 25, 2017 04:42

"File not found" on Linux could be trying to run 32 bit executable on 64 bit system or vice versa

Posted by admin |

The file is clearly there, you ls it, view it and everything. but when you try to run, it's reported as not being there. You could be on the wrong sub architecture like 64 bit when the execiutable is 32 or vice versa: perl - Getting "Not found" message when running a 32-bit binary on a 64-bit system - Unix & Linux Stack Exchange

 

In my case it seemed to be running a 64 bit executable on a system that had a bit of an identity crisis as to what it were, byte-wise.

Apr 21, 2017 05:55

Powering a 2-pole 3.5mm (1/8") connected electret microphone with a Xenyx 302USB

Posted by admin |

There is a 3,5mm (1.8") microphone jack at the top right of the Xenyx 302USB.

It seems to be wired the same as in SoundBlaster sound cards, and have a 4V voltage for driving electret condenser microphones:

        / \ 
       |   |   Tip - Audio signal
        \ / 
       +===+
       |   |   Ring - Bias voltage for microphone (+4V)
       |===|
       |   |
       |   |   Sleeve - Ground
       |   | 
     +=======+
     |       |

Schematics adapted from: Powering microphones

However my electret microphone seems to be wired like this:

        / \
       |   |   Tip - Audio and bias voltage (+3V)
        \ /
       +===+
       |   |  
       |   |
       |   |
       |   |   Sleeve - Ground
       |   |
     +=======+
     |       |

I think it runs on 3V so 4V is close enough I guess.

So I am using a wiring block to make the ground not extend to the ring, and have the signal + voltage on both the ring and the tip, going into the mixer:

        / \ 
       |   |   Tip - Audio and bias voltage (+4V)
        \ / 
       +===+
       |   |   Ring - Audio and bias voltage (+4V)
       |===|
       |   |
       |   |   Sleeve - Ground
       |   | 
     +=======+
     |       |



Source quote for the voltage:

The 302USB does not have the higher voltage phantom power used in older mixers. It does have the 14 volt on the XLR and the 4 volt on the 1/8' (3.5 ) bias for electert mics. This is not something you can turn off but is not a problem unless you are using equipment that is not isolated or balanced and then you can get noise from cable movements, inserting plugs with the volume up. Hope this helps.

Amazon.com: Questions And Answers: Can I use this preamp without phantom power? and if so, how?

Apr 14, 2017 04:30

Ubuntu Linux on Aspire V15 Nitro - first impressions

Posted by admin |

It works with Ubuntu 16.04LTS, 16.10 and 17.04 and with  Fedora Linux with the following caveat:

Furthermore, this is not a bug, but the M2 SSD does not support encryption (Opal encryption) which surprised me a bit.

Apr 12, 2017 04:50

Let's just call them superstitious

Posted by admin |

Yesterday, as I walked home from my work at Vasagatan, I saw hundreds of people walking on Västerbron bridge making their way home, after the attack at #Drottninggatan. My heart goes out to those hurt and killed by the terrorists.

In ancient Rome, before Christianity and before Islam, there was an expression for people who think they are gods or who think they could manipulate gods to do their bidding: They were not seen as religious, but superstitious (superstitio).

Imagine if we could deny the "religious" label to people who do not respect the right to life or the UN declaration of human rights. We simply deny them the protection and respect we extend to others to worship in freedom. Criminals will not longer be able to hide behind a perversion of piety.

People who preach hate are just recruiters for criminal organizations and networks and should be treated as such. Insofar as their ramblings can be interpreted as threats or incitement to violence, they should be prosecuted to the fullest extent of the law, without any regard to hurting religious feelings, since this is not religion.

We are entering an age where small groups can do a lot of damage; a sect of a couple of thousand tops were close to wiping out many many people in Japan some years ago. Three times. The freedom of communication we have now will in the future mandate a lot more physical protection. And we need to communicate more in person:

If any people are close enough to hurt you, you need to communicate with them, engage them. We must reach the people who have Internet fueled make-believe communities in their heads.

Theirs is a path of bitterness, hate and delusion, their perceived self-worth oscillating between the extremes of self-hatred and self-aggrandizement.
Our path is one of love, joy and freedom, knowing in our hearts without hesitation the true value and power of humans. We will prevail.

Apr 08, 2017 06:40

Thoughts on U2F

Posted by admin |

U2F is an authentication standard pushed by among others, Google. It is used for two factor authentication, where a USB dongle or NFC is used to cryptographically sign a response to a request from the party that requires you to authenticate. Here are my thoughts so far. I basically think it's good but I piled on more on the bad side below:

The good:

  • Cryptographically signing a response is really smart and potentially very secure. It is similar to how Bitcoin works. It is more secure, if the device signing has its own display so you can verify what it outputs. Otherwise you may just think you are signing something, and in fact your nefarious computer is in fact signing with something else.

The bad

  • It needs to communicate with a computer, and this is for obvious reasons done over a standard interface, such as USB. Which interface is a little bit over-expressive in its communication abilities. Which means that secure computers disable USB access. And now you have nowhere to stick your dongle.
  • A popular security measure now is sandboxing and virtualization, such as with Qubes OS. If you are using a dongle, you now need to route the USB port to that virtual machine.
  • Currently only Chrome supports it, but that may change. My Linux Firefox refuses, in spite of extension and udev rules. I may have done something wrong but then again, there you go.
  • Many sites and services seem happy with OTP, and are not in the process of switching over: USB Dongle Auth List
Apr 06, 2017 12:05
Ads