Velocity of air flow around aerofoil

enter image description here

To find the velocity of the air flow at each section of the aerofoil, am I right to say that the horizonatal velocity of the air flow is constant throughout the chord while the vertical component of the velocity varies along the chord depending on the angle of chord w.r.t. horizontal?

So velocity at first plane is $frac{U}{cosbeta}$?

If that is the case, will shifting the air upwards, not push the wing down? Or am I right to say that as the airflow around the wings, there is no net upward motion of air, thus it does not push the wing downwards?

All topic

Mouse pointer bounces around when using touchpad

Hello I just installed Elementay OS and I am running into a problem when using touchpad. My mouse point is shaky when I am using touchpad. My laptop is Dell Inspiron 3000.

This does not work:
Shaky mouse pointer when using touchpad

All topic

Freon leak around dryer -Honda Accord 2000 SE

after I turned A/C, engine room started smoking and it turned out it’s coming from the leak around the receiver/dryer of A/C. There are two pipes to it. unsure which is high or low but I tried to fasten and it wouldn’t stop the leak. I can hear the hissing sound from the dryer. When I loosen abit, more coming from the pipe to the dryer. I think I found the exact spot of the leak.

To fix it,

I wonder if I need to replace the dryer or is it something I can fix by adding some seal?

All topic

Name of song in Episode 9 of No Game No Life at around 21:45?

What is the name of the song played in Episode 9 of No Game No Life at around 21:45? I can’t seem to find this song anywhere.

All topic

Can a star orbit around multiple planets or a planet with massive moons?

Note: I’m not talking about a star orbiting around a single or lonely planet 🙂

I know a star orbiting a planet is almost impossible because if a planet is more massive than a star, that “planet” would probably be a star. But how about if the planet is not lonely like:

  1. A multiple planetary system which consists of free floating planets only but the planets are so massive so that their total mass is larger than a star

  2. A planet itself is not more massive than a star but it has so many massive moons

Is it possible for a very small star to orbit around planets in such situations?

All topic

Low mass cut-off for the Dharma Planet Survey’s detection of habitable planets around 40 Eridani A?

News of the discovery of a potentially habitable planet around the star 40 Eridani A (about 16 light-years away) is interesting for reasons including a 1991 letter described below in Sky & Telescope’s recent article Super-Earth Discovered in (Fictional) Vulcan System, part of which is shown below.

Question: Is there any way to estimate a low mass cut-off for the Dharma survey for this particular star? Could there also be a 1 or 2 Earth mass planet there as well, within a habitable zone, as-yet undetected? Or does data there exclude this possibility?

The paper about the recent discovery: https://arxiv.org/abs/1807.07098

Almost three decades ago, Gene Roddenberry (producer of the Star Trek universe) wrote a letter to Sky & Telescope, along with Harvard-Smithsonian Center for Astrophysics astronomers Sallie Baliunas, Robert Donahue, and George Nassiopoulos. In their Letter to the Editor, they argued that 40 Eridani A — an orange-ish star 16 light-years away — would make the ideal home for Vulcan, the home planet of Science Officer Mr. Spock.

Now, a new discovery puts a little more science into that science fiction assertion.

A Long-ago Letter

In the July 1991 issue, the three astronomers and one movie-maker made the case for what star should be considered Vulcan’s home:

The star around which Vulcan orbits was never identified in the original series or in any of the feature films based on it and so has never been officially established. But two candidates have been suggested in related literature.

Two Star Trek books named the star 40 Eridani A as Vulcan’s sun, while another publication named Epsilon Eridani instead. However, Roddenberry and the astronomers made an argument for 40 Eridani A:

We prefer the identification of 40 Eridani as Vulcan’s Sun because of what we have learned about both stars at Mount Wilson. . . . The HK [Project] observations suggest that 40 Eridani is 4 billion years old, about the same age as the Sun. In contrast Epsilon Eridani is barely 1 billion years old.

Based on the history of life on Earth, life on any planet around Epsilon Eridani would not have had time to evolve beyond the level of bacteria. On the other hand, an intelligent civilization could have evolved over the aeons on a planet circling 40 Eridani. So the latter is the more likely Vulcan sun. . . . Presumably Vulcan orbits the primary star, an orange main-sequence dwarf of spectral type K1. . . . Two companion stars — a 9th magnitude white dwarf and an 11th magnitude red dwarf — orbit each other about 400 astronomical units from the primary. They would gleam brilliantly in the Vulcan sky.

All topic

been tampered? been filtered ? or just a network settings messing around?

I’m using qubes for some times now.

after some weeks to correctly configure my setup, I want to figure it out why sys-whonix is not working correctly with my setup.

so I closely look at the other threads with one same criteria, the message in the logs : (“server rejected connection”)

one in particular attracted my attention. So I’ve tested some advices on this same website. So I’ve connected through the wifi access point from my phone and through my LAN wired network. The differences are heavy.

first some informational point:

  • the LTE data network and my VDSL2 Line are from the same provider which is Proximus in Belgium (important point to dissipate any doubt about the fact if I’m in a restricted area or not).

  • My LAN Network is organised with VLANs through managed switches and then through a router which is connected wiredly to an ISP box/router but its my router which does the PPPOE connection not the ISP box.

  • I didn’t do a DMZ zone for this qubes client but the router/firewall rules are pretty basics

  • My work/personal life are sort of mixed with the justice department and to my knowledge there are no specific filters from ISP in belgium but I could be wrong if I am don’t hesitate to correct me.

  • I have pinged all the bridges and all except one answered.

So here are the logs through the LTE access point:

Events (TOR/ARM NOTICE - ERR):
 12:48:28 [WARN] Proxy Client: unable to connect to xxxxxxxxx:xxxxx ("server rejected connection") [2 duplicates hidden]
 12:48:28 [WARN] Proxy Client: unable to connect to xxxxxxxxx:xxxxx ("server rejected connection") [2 duplicates hidden]
 12:48:28 [WARN] Proxy Client: unable to connect to xxxxxxxxx:xxxxx ("server rejected connection") [2 duplicates hidden]
 12:28:55 [NOTICE] Tried for 120 seconds to get a connection to [scrubbed]:80. Giving up. (waiting for rendezvous desc) [1 duplicate hidden]
 12:28:35 [NOTICE] New control connection opened. [7 duplicates hidden]
 12:26:34 [NOTICE] New control connection opened from 127.0.0.1. [3 duplicates hidden]
 12:26:30 [WARN] Socks version 71 not recognized. (Tor is not an http proxy.)
 12:26:29 [NOTICE] Bootstrapped 100%: Done
 12:26:29 [NOTICE] Tor has successfully opened a circuit. Looks like client functionality is working.
 12:26:28 [NOTICE] Bootstrapped 90%: Establishing a Tor circuit
 12:26:28 [NOTICE] new bridge descriptor 'niffierlaterals' (fresh): $F68BBB77DA245790969057EE608E6B14283655EB~niffierlaterals at xxxxxxxxx:xxxxx
 12:26:27 [ARM_NOTICE] Unable to prepopulate bandwidth information (insufficient uptime)
 12:26:27 [ARM_WARN] The torrc differs from what tor's using. You can issue a sighup to reload the torrc values by pressing x.
   - configuration values are missing from the torrc: HiddenServiceStatistics, RunAsDaemon
 12:26:27 [ARM_NOTICE] Tor is preventing system utilities like netstat and lsof from working. This means that arm can't provide you with connection information. You can change this by adding 'DisableDebuggerAttachment 0' to
   your torrc and restarting tor. For more information see...
   https://trac.torproject.org/3313
 12:26:27 [ARM_NOTICE] No armrc loaded, using defaults. You can customize arm by placing a configuration file at '/home/user/.arm/armrc' (see the armrc.sample for its options).

here are from the wired network

 13:12:53 [NOTICE] Tried for 120 seconds to get a connection to [scrubbed]:0. Giving up. [60 duplicates hidden]
 13:12:53 [NOTICE] Bootstrapped 100%: Done
 13:12:53 [NOTICE] Tor has successfully opened a circuit. Looks like client functionality is working.
 13:12:53 [NOTICE] Bootstrapped 90%: Establishing a Tor circuit
 13:12:53 [NOTICE] Bootstrapped 80%: Connecting to the Tor network
 13:12:51 [NOTICE] Bootstrapped 25%: Loading networkstatus consensus
 13:12:50 [NOTICE] Tried for 120 seconds to get a connection to [scrubbed]:0. Giving up. (waiting for circuit) [69 duplicates hidden]
 13:10:39 [NOTICE] Tried for 120 seconds to get a connection to [scrubbed]:443. Giving up. [2 duplicates hidden]
 13:09:58 [WARN] Proxy Client: unable to connect to xxxxxxxxx:xxxxx ("server rejected connection")
 13:09:58 [WARN] Proxy Client: unable to connect to xxxxxxxxx:xxxxx ("server rejected connection")
 13:09:58 [WARN] Proxy Client: unable to connect to xxxxxxxxx:xxxxx ("server rejected connection")
 13:08:21 [WARN] Proxy Client: unable to connect to xxxxxxxxx:xxxxx ("TTL expired")
 13:08:21 [WARN] Proxy Client: unable to connect to xxxxxxxxx:xxxxx ("TTL expired")
 13:07:54 [ARM_WARN] The torrc differs from what tor's using. You can issue a sighup to reload the torrc values by pressing x.
   - configuration values are missing from the torrc: HiddenServiceStatistics, RunAsDaemon [2 duplicates hidden]
 13:07:54 [ARM_NOTICE] Reconnected to Tor's control port [1 duplicate hidden]
 13:07:50 [ARM_NOTICE] Tor control port closed [1 duplicate hidden]
 12:26:27 [ARM_NOTICE] Unable to prepopulate bandwidth information (insufficient uptime)
 12:26:27 [ARM_NOTICE] Tor is preventing system utilities like netstat and lsof from working. This means that arm can't provide you with connection information. You can change this by adding 'DisableDebuggerAttachment 0' to
   your torrc and restarting tor. For more information see...
   https://trac.torproject.org/3313
 12:26:27 [ARM_NOTICE] No armrc loaded, using defaults. You can customize arm by placing a configuration file at '/home/user/.arm/armrc' (see the armrc.sample for its options).

So with the LTE network I had immediately a connection. Between the two tests I’ve of course restart tor and ask it to reconnect. When I was on the wired network like always, I had some but mostly no connection. You can notice it in the logs and through the timestamp too.

So is it my ISP preventing me to go to Tor? Is it a problem with my router setup ? Is it something else in my wired networked? Does these messages of server rejected connection come from the bridge itself or is it a generic message from ARM? What should I do to have access permanently to Tor through my wired network? Which tests should I do and how to proceed? Should I add pages and pages of bridges?

Here is the configuration of tor user configuration file from sys-whonix.

DisableNetwork 0
UseBridges 1
ClientTransportPlugin obfs2,obfs3 exec /usr/bin/obfsproxy managed
ClientTransportPlugin obfs4 exec /usr/bin/obfs4proxy

bridge obfs4 xxxxxxxxx:xxxxx 4F815C00771B178C0EB06FDB7293BDB1BD353E03 cert=VaCBcwj1MO3waCsl+Yq/Vuu20dP7fKI92fsvpoMTqlkOHROk/RnX4tx1oFhP7E9YWaOZFA iat-mode=2
bridge obfs4 xxxxxxxxx:xxxxx 08077A0B1248B8FC1E7C114771D3C7A9A3954D71 cert=0jrTOIV/73tSsFwi79k4Vo5rNkmIdK39SlNgv/JUOTS/yRFzeyuSr4DrkwF+Wj+lTJnHSg iat-mode=2
bridge obfs4 xxxxxxxxx:xxxxx E58F54184935689AC7BFD983FB887AFE2D443B4D cert=S+0Tez9y9+q6LUsi658pYXzDHfS+dpSS8UHMsy3OXQvuvA8GtnoQNkWG1KmihXZqt6Yqdg iat-mode=2


bridge obfs3 xxxxxxxxx:xxxxx F4B33297F39EC5CF2EFD0E3D2F3EB87EC8428237
bridge obfs3 xxxxxxxxx:xxxxx 2C3FDA0289A5627ECB582C0A61620780473A46FD

bridge obfs4 xxxxxxxxx:xxxxx F68BBB77DA245790969057EE608E6B14283655EB cert=lxPxDTtghn56dGKbQ2vicevpXiUHNzJpSxCLMd76A8MhbKPVQqurd9Uf4sx7yOfYDA5dBw iat-mode=0
bridge obfs4 xxxxxxxxx:xxxxx F4B33297F39EC5CF2EFD0E3D2F3EB87EC8428237 cert=Ax+LafRJEU1v5BGdXV0To86Vs+gr+EPbIvOZE3iL/fAY3pxScQppxW5y8e03DSCJuqZlCA iat-mode=0
bridge obfs4 xxxxxxxxx:xxxxx D28E0345809AE4BAC903EF7FC78CAAF111A63C58 cert=DtNNYXeRG4ds+iTM7sdbJHJgH7RmxDb1lt8JR17BiT7eHnORyn+4y+RcoqAI65XGvhXKJg iat-mode=0

I’ve added some bridges of different kind based on the advices here. And all the addresses come from whonix.

All topic

What can I do to ensure I only erase the smaller details without affecting the area around it?

I don’t draw much and can’t even call myself an amateur yet. As a result I make a lot of mistakes and also many test strokes when drawing.

For small touch ups and mistakes the eraser is my best friend. However, my big white eraser does not help much when I need to only make small corrections. It can remove larger areas around where I am erasing.

Let’s say I am talking about erasing small areas less than a centimeter in diameter. What can I do to make my erasing more targeted and only affect the areas I want to remove?

All topic

How to use the “build a community around your business” new Facebook feature?

Facebook added a new feature that encourages you to create a Facebook group associated with the Facebook page of your business. Supposedly this would be better for your business. So far, after you associate a page with a group, I’ve seen these features.

  • The Facebook page becomes admin of the group
  • The Facebook page is linked in the top part of the group
  • The Facebook page is linked at the right of the group
  • The group is linked in the Facebook page
  • They encourage you to create a post in your Facebook page for promoting the associated Facebook group.

But I haven’t seen any change in activity neither in the Facebook page nor the Facebook group. Is there anything more you can do with these features? or are there more features related to this I havent seen?

All topic

Female dog suddenly timid around men, scared of everyone after moving to a new home

Two months ago I started dating my partner and his dog, a 6 year old Labrador. When I first met her she was excited, happy, and licked me all over. She was happy around everyone; we took her on trips where she met strangers and loved them.
One day at random she barked and growled at a male friend (a stranger to her), which was out of the ordinary for her personality. I thought she was just moody.
Then she’s herself again, happy and loving

The real estate came to show new tenants the house and she wouldn’t let the man into her yard

Now, a few weeks later, she’s moved to my house on some land with my partner and I.
Suddenly, she wont tolerate anyone; she growls at my parents, my sister, and my friends. She acts scared and growls and runs away.
This is totally not like her.
I’m frustrated because of her dramatic attitude change, five weeks ago she was playing with strangers. I know moving can be traumatic. Can someone please give me some advice and tips and tricks? It would help me out!

All topic