• About the Trash in Mac OS X: a brief overview of the Trash architecture.
• Techniques for solving Trash problems: common approaches to a variety of Trash problems, including:
  • Trash utilities for eradicating troublesome files.
  • Force the Trash to empty using the Option key.
  • Empty and recreate an account’s Trash.
• Resolving common Trash problems: solutions for the following common Trash problems:
  • Moving locked files to the Trash.
  • Locked files in the Trash.
  • Files in use by other applications.
  • Insufficient privileges needed to Trash an object.
  • Incomplete Internet downloads under Jaguar.
  • Files dragged to the Trash “will be deleted immediately” alert.
  • Immutable files.

This FAQ applies to:

• Mac OS X 10.5 Leopard®
• Mac OS X 10.4 Tiger®.
• Mac OS X 10.3 Panther®.
• Mac OS X 10.2 Jaguar.

About the Trash in Mac OS X

Mac OS X introduced a new architecture for Trash:

• Each user has their own private, hidden, and invisible Trash folder, located in their Home folder. The UNIX® directory path for this folder when logged in to your account is~/.Trash.
• Because each user’s Trash is private, viewing the contents of the Trash shows only objects which you have placed into the Trash.
• If you have secondary hard drives or other writable volumes connected to your Mac, each may contain an invisible Trash folder named .Trashes, which in turn contains an invisible Trash folder for each user.
• When you open Trash to view its contents, it appears that all of the objects you have trashed are in a single Trash folder. In reality, Trash is displaying a list that is the union of the contents of all of the individual Trash folders associated with your account, on all writable volumes.

Techniques for solving Trash problems

Trash utilities for eradicating troublesome files

You may want to download and install the freeware utility Trash It! or the shareware utilityCocktail. Using one of these utilities is often the fastest way to Trash recalcitrant files.

Note: Be sure to employ a version of the utility that is compatible with the version of Mac OS X you are using.

Force the Trash to empty using the Option key

This technique uses a hidden feature of Mac OS X to force the Trash to empty. Perform the following steps in the order specified:

1. Press and hold the mouse button on the Trash icon in the Dock. The context menu for Trash will display.
2. Press and hold the Option key.
3. Select Empty Trash from the context menu for Trash.
4. Release the Option key.

Empty the Trash of an affected account.
Create a new ~/.Trash directory, with correct ownership and permissions, for that account.

Resolving common Trash problems

Moving locked files to the Trash

Mac OS X 10.2 – 10.4 prevent you from moving locked files to the Trash; Mac OS X 10.5 permits locked files to be moved to the Trash.

Locked files display a lock badge in the lower-left corner of their icons. Under Leopard, the lock badge only appears if Show icon preview is deselected in the View Options (View > Show View Options) of the Finder window containing the locked file.

Use the following procedure to unlock a file so that it can be moved to the Trash.

1. Open the Get Info window for the file by either:
   1. Selecting the file’s icon in Finder™ and pressing the Command-I keyboard combination.
   2. Control-clicking the file’s icon in Finder and selecting Get Info from the file’s context menu.
2. In the General panel of the file’s Get Info window, deselect the Locked checkbox. The check mark will disappear, indicating the file is now unlocked.
3. Close the Get Info window for the file.
4. Trash the file.

Locked files in the Trash

Try one or more of the following methods to delete locked files in the Trash:

• Force the Trash to empty using the Option key.
• Use one of the recommended Trash utilities.
• Unlock the file using the procedure in “Moving locked files to the Trash.” Then empty the Trash.
• Empty and recreate the affected account’s Trash.

Files in use by other applications

Use one or more of the following methods if you receive a message indicating that a file can neither be moved to the Trash, nor emptied from the Trash, because it is “in use” by another application.

1. Quit the application that is using the file. This will usually permit you to then move the file to the Trash or to empty the Trash.
2. If you are unsure of the application that has the file “in use,” the Terminal commandlsof can tell you the name of the process or application that Mac OS X considers to be using the file, as follows:
   1. Click the Trash icon in the Dock. A Finder window opens showing the contents of your Trash.
   2. Open Terminal, located in the Macintosh HD > Applications > Utilities folder.
   3. Position and resize, if necessary, both the Finder window showing the Trash and the Terminal window so you can simultaneously see both windows fully.
   4. At the Terminal prompt type lsof followed by a single space, but do not press Return yet.
   5. Drag and drop the file “in use” from the Trash — the Finder window opened in step 1 — to the Terminal window opened in step 2. The path to the file will appear after the lsof command typed in step 3, i.e. you will see
      1. lsof /path_to_file
   6. Press Return.
   7. If the file is “in use” then the output from lsof will list the names of the applications or processes which claim to be using the file under the first column heading, COMMAND.
   8. If the file is “in use” by an open application, Quit (Command-Q) that application. If a background process has the file “in use,” you can use Activity Monitor (Tiger, Panther) or Process Viewer (Jaguar) to Quit that process.
   9. Note: One must be careful when quitting processes as certain background processes are needed for Mac OS X. Quitting processes like loginwindow orkernel_task could force you off your account, freeze your Mac, or cause a kernel panic. If you do not know what effect quitting a process may have, do not quit the process.
3. Force the Trash to empty using the Option key.
4. Log out, log in, and then attempt to empty the Trash.
5. Restart your Mac, log in, and then attempt to empty the Trash.
6. Use one of the recommended Trash utilities.
7. Empty and recreate the affected account’s Trash.

Insufficient privileges needed to trash an object

Warning: If Mac OS X informs you that you have insufficient privileges to delete a file, this may be because you are attempting to delete a System-related file. You should not delete System-related files unless you are absolutely sure you know what you are doing. Deleting System-related files could render your system unusable.

If you are informed that you have either insufficient privileges or insufficient permissions to trash a file or folder, you may be able to trash the object in question using the following procedure.

1. Make yourself the Owner (Tiger and eariler) of the file or add yourelf under Name (Leopard) for the file, with Access (Tiger and earlier) or Privilege (Leopard) of Read & Write, using the instructions in the Mac Help document from the following list corresponding to the version of Mac OS X you are using:
   1. “Mac OS X 10.5 Help: Setting permissions.”
   • “Mac OS X 10.4 Help: Setting permissions for disks, folders, and files.”
   • “Mac OS X 10.3 Help: Setting permissions for disks, folders, and files.”
   • “Mac OS X 10.2: How to Change Ownership & Permissions Using the Finder.”
2. Trash the file.

Incomplete Internet downloads under Jaguar

Downloads which fail to complete can sometimes leave you with files which can neither be moved to the Trash nor emptied from the Trash.

1. If the downloaded file is in the Trash, try one or more of the following procedures to empty the Trash:
   • Force the Trash to empty using the Option key.
   • Use one of the recommended Trash utilities.
   • Empty and recreate the affected account’s Trash.
2. If the downloaded file cannot be moved to the Trash, try the procedure in the AppleCare® Knowledge Base document “Mac OS X 10.2: Cannot Delete an Incomplete Copy or Download.” In particular, try the TextEdit tip.

Files dragged to the Trash “will be deleted immediately” alert

When dragging files to the Trash from removable media, such as a Zip® disk, it is common for Trash to inform you that the files will be deleted immediately. This appears to have been a design choice due to every writable volume having its own hidden Trash folder. If you ejected the Zip disk before emptying the Trash, the files you thought were deleted would still be in the Zip disk’s.Trashes folder at the root (top) level of its directory. Hence Mac OS X will immediately delete files moved to the Trash from removable media. This also depends upon the firmware of the device informing Mac OS X that it is a removable media device. Some removable storage devices identify themselves as hard drives, meaning that items remain in the .Trashes folder if the removable storage device is ejected before the Trash is emptied and will reappear in the Trash when the device is again connected to your Mac.

If you are not dragging files from removable media to the Trash and are informed that files dragged to the Trash “will be deleted immediately,” there are three possible causes:

1. You are either no longer the Owner of your Home folder, do not have Access of Read & Write to such, or both.
2. Your account’s Trash, i.e. your ~/.Trash directory, has been deleted.
3. You no longer are the owner of your account’s Trash.

To resolve this problem, proceed as follows:

1. Assure you are the Owner (Tiger and eariler) and have Access (Tiger and earlier) or Privilege (Leopard) of Read & Write on your Home folder:
   1. In Finder, press the Command-Shift-H keyboard shortcut. A Finder window opens showing the contents of your Home folder.
   2. Press the Command+I keyboard shortcut. The Get Info window for your Home folder opens.
   3. Select the Get Info window.
   4. Open the disclosure triangle for the Ownership & Permissions panel (Tiger and Earlier) or the Sharing & Permissions panel (Leopard) in the Get Info window.
   5. If using Panther or Tiger, open the disclosure triangle for the Details panel within the Ownership & Permissions panel.
   6. If you are not listed as Owner (Tiger and earlier) or under Name (Leopard) or do not have either Access (Tiger and earlier) or Privilege (Leopard) of Read & Write, then correct these issues using the instructions in the Mac Help document from the following list corresponding to the version of Mac OS X you are using:
      1. Warning: When using the instructions in the following Mac Help documents, do not use the Apply to enclosed items option, if available.
      2. “Mac OS X 10.5 Help: Setting permissions.”
      3. Leopard users can also start up from their Mac OS X Leopard Install DVDand use the Reset Home Directory Permissions and ACLs function of the Reset Password function of the Utilities menu.
      4. “Mac OS X 10.4 Help: Setting permissions for disks, folders, and files.”
      5. “Mac OS X 10.3 Help: Setting permissions for disks, folders, and files.”
      6. “Mac OS X 10.2: How to Change Ownership & Permissions Using the Finder.”
   7. Close the Get Info window.
   8. Try to place objects in the Trash. If so, the problem is solved: stop here. Otherwise, proceed to the next step.
2. Verify that your ~/.Trash directory exists:
   1. Open Terminal, located in the Macintosh HD > Applications > Utilities folder.
   2. At the Terminal prompt, type the following command exactly as written:
      1. ls ~/.Trash
   3. Press Return.
   4. If the response contains “No such file or directory” then:
      1. Either log out of your account or restart your Mac.
      2. Log in to your account. You should now be able to add objects to the Trash: stop here.
   5. Otherwise, proceed to the next step.
3. Empty and recreate your account’s Trash.

Immutable files

There are rare issues which can inhibit emptying the Trash. These include immutable files and files on which the system immutable bit has been set. If an object cannot be deleted using any of the preceding methods, you may have encountered this rare situation. Dealing with immutable files is covered in the following resources:

• The AppleCare Knowledge Base document “Unable to move, unlock, modify, or copy an item in Mac OS X.”
• The tutorial “How to Fix Stubborn Trash Problems” on OSXFAQ.

Going by the simple definition of Internet marketing, it is an underlying key to your website promotion.Standing out in today’s hyper-competitive online marketplace is not an easy task. Here is when internet online marketing techniques unveil their potential. They teach you to leverage ways by which you can provide your visitors with exactly what they are searching for, and SEO provide a particular and excat thing what they are searching for.

So that Search engine optimization plays a very important advantage in web marketing and web site promotion for boosting the business functionality and escalating the business ranking of the web site.

2. Get back links from articles, the best links come from article that links to from the article itself, this way the links are highly shown in page code

3. Bookmark this page, and try to have at least 3 bookmark accounts to bookmark your site, or find some partners to bookmark for you. Links from bookmark sites are great

4. Build profile pages and other pages with social network sites (Search for “list of websites similar to myspace) and you will find some good social networking sites to build pages there. Bookmark all your social pages and link them to each other while all of them links to your site. (its called wheel linking) if you have any automated link building tool try to build some links to those pages.

5. To reach top ranking and stay there you need to have back links from blog posts all the time. You can find some bloggers to post your articles or you can find some tool to connect you with bloggers ( see signature). And if you can have a new article every week published in at least different 20 blogs it will be great. As an extra have at least 3 blogs of your own and always post to them and link to them.

It require time but it’s very effective.

1.) Write Captivating Articles -

Article marketing is one of the best ways to attain traffic as it is almost always free and can allow a marketer to express their interests in any desired niche. If you submit articles to directories you are not only getting a steady stream of readers, but you are also building backlinks to your blog site. An example is EzineArticles.com, as it is has its own readership of people looking for topics that you may just be blogging about. Therefore, if you write an article and submit it to a directory a person will not only read your article but also be enticed to visit your blog.

2.) Reasons to Re-Visit-

Giving people a reason to go back is seen all throughout commercial businesses. For example, stores and restaurants will hold special sales, events, and offers to keep customers coming back for more of what they love; but this time with a lower price or “buy one get one free” offer. This exact formula can also be replicated in your blogging techniques. The idea to keep people coming back over and over can be lucrative and the best way to do this is to create special events and offers. For example, you can give away a new prize each week to new subscribers to your list. In addition, you can also run contests for people who leave comments on your blog posts. In short, making your blog “a place to be” will attract more people as your subscribers may even tell their friends.

3.) Doing Keyword Research-

Rather than throwing up blogs and expecting traffic it would be wiser to research the keyword data to find terms that are getting a lot of searches. In addition, attaining keywords that have low competition would be a greater choice as it will make your blog easier to rank.

4.) Link Baiting-

The idea behind creating link baits is stirring enough controversy through your post that you can produce strong emotional reactions by people in order for them to comment and link to your blog post. For example, if a hot new electronic product; like the iPad, just recently came out on the market and everyone is raving about it, you can explain why you don’t like it to your readers in a way that will give you strong emotional responses automatically.

In short, these are four ways that can be solid; if used appropriately, in bringing in more traffic and attaining a base of avid readers

schematic diagram for Infrared Flame sensor Switch

part list :

1. T1, T2 25K to 50K ohm thermistor

2. R1 33K ohm

3. R2 50K potensio

4. R3 1K ohm

5. R4 47 ohm

6. D1 1N4002

7. Q1 2n2222

8. RY-1 SPDT 6 volt relay

9. U1 LM741

10. B1 9V battery

11. S1 SPDT toggle switch

schematic diagram for Infrared Flame sensor Switch

click here for project,
1. infrared flame detector
2. freeze alarm
3. over temperature monitor
4. analog data logger

The addition of a parabolic reflector further enhances the performance of this project. because ultrasonic frequency spectrum is beyond our hearing range, they can listened to only by indirect means, such as frequency heterodyning. frequency heterodyning is a method widely used in modern radio receiver.

in an ultrasonic receiver with frequency heterodyning, a local oscillator (LO) is used to generated square wave. the output of the LO is from 20 to 100KHz. the incoming signal (FI) is first pick up by an ultrasonic transducer and then amplified by a three stage amplifier. the input signal is then mix by a the mixer section to produce a sum (LO+FI) of the frequencies and a different of frequencies(LO-FI) at the mixer output. because the sum of frequency (LO+FI) is too high to be heard, it is filtered out. the difference of frequency (LO-FI) is just within the audio range of frequencies. therefore after amplification, it can be heard from a loudspeaker or headphones. a system block diagram is shown in figur 1.

Figure 1. Ultrasonic Listening Block Diagram

a special piezoelectric ultrasonic transducer acts as a microphone and it used to detect the high frequency ultrasound waves. whenever sound pressure is applied to the transducer, it will produce a small voltage at its output terminal. the frequency response of this transducer peaks around 40KHz but will work from 20 to 100KHZ. this weak signal from the transducer is passed to input pin 9 of the CD14069 integrated circuit (IC) at U1: a, a Hex inverter IC. this digital IC operates in the linear mode by connection feedback resistor R2,R3, and R5 from the inverters’ output back to their inputs. the weak signal from the transducer goes through three stages of amplification at U1:d U2:e and U1:f the signal is then rectified and coupled to the mixer by C7. the schematic diagram of ultrasonic listener can be see at figure 2.

APPLICATION

HYDROPHONE LISTENER


The hydrophone listening system is composed of two parts, a hydrophone or microphone pre-amplifier assembly and an electronic amplifier assembly linked together by coaxial cable.