Living Dangerously with Chemicals

There are several ways to create a PCB and one of those ways is called acid etching. This PCB fabrication method works by chemically removing unwanted copper from the board. Resistances are placed on the portions of the copper board that one wants to remain after the etching process.

One chemical of choice is ferric chloride. This acid is usually a cheaper option than other chemical compounds used for etching. There are two types of this acid and one type is called hex hydrate ferric chloride. This type comes in a light yellow colored powder and is usually dissolved in water with about a tablespoon of salt for a clearer, easier inspection of the PCB when it is submerged in it. The other type is called anhydrous ferric chloride which is a green-brown colored powder. This is a more dangerous chemical and it is highly discouraged to be used but if one decides to, observe extreme caution when dissolving this in water as it creates a lot of heat. Never add water to the powder, add it to the water instead.

pcbThere is a chance that this chemical may not successfully etch the board, making it far from ideal for PCB fabrication. If this happens, one can add a small amount of hydrochloric acid and leave the board submerged in it for about two days. When using any of these etching chemicals, use a ceramic or a plastic container, be sure to use gloves and safety glasses when handling such chemicals as they can be damaging to the eyes and skin; also, avoid splashing at all costs.

Another acid of choice in PCB fabrication is sodium per sulfate. This is a white-colored powder that is a good etching solution for copper printed circuit boards. This chemical has some advantages over ferric chloride and other similar copper-etching chemicals. Unlike ferric chloride, sodium per sulfate does not stain clothes, skin, or containers. It leaves no residue in plain water and rinses quite easily. Its etching speed is faster and it maintains a good etching rate throughout its mixing life.

As to be expected though, this chemical also comes with disadvantages when compared with other etching chemicals. Sodium per sulfate has a shorter mixing life (or, in a way, durability) when used in an etch tank; it has a maximum of three weeks regardless if it is being used or not. If ferric chloride triggers a potentially dangerous reaction with metals, sodium per sulfate reacts in the same way upon coming into contact with natural fibers such as linen, cotton and wool.

In addition to those already mentioned, other chemicals can be used as etching agents for the PCB – these include hydrogen peroxide and hydrochloric acid. Same with ferric chloride, a non-metallic container is needed for this as well. Mix two parts of hydrogen peroxide with one part hydrochloric acid; by doing that you’ll create a good etching agent. While etching with these chemicals, make sure that the area is well ventilated. In addition to this, acetone is needed to remove the resist from the PCB after etching. Compared to the other methods discussed, this may be the safest for etching the PCB with chemicals. However, extreme caution should still be observed.

When using any of these PCB fabrication methods, always remember to be safe. Be cautious when handling dangerous chemicals and be sure to prepare everything that is needed to keep the etching area secure. Also, follow the instructions very carefully, including those about the proper disposal of such chemicals. Keep in mind that any mistakes can cause serious damage not only to one’s surroundings but even to oneself.

SEO : what is it ?

SEO, or Search Engine Optimization, is not just another fancy acronym from Silicon Valley. Used as early as the 1990s, it is an all-encompassing, umbrella phrase about the actual processes involved in making any content visible to any user who has inputted the right keywords in the many online search boxes available today.

seoWith the multitude of search options available to the masses, including searching for images, domestic or international businesses, job listings, attractions, events, academic articles, and even public journals or government documents, each content must be studied carefully, and must include enough selling points to find the best optimization tool for that kind of media before uploading it to the web.

Once up and online, anything can come up on a search result.

Note, however, that appearance alone does not count. A website must rank high on the results to be placed on the first page, and on the number one slot, where it is most likely to be seen, clicked, visited, and linked back on.

If the media is robust, and the public interest is high enough, the rank of the content, as it appears in search results, may move higher on its own accord. Even so, it may be just low enough that internet users may have to scroll down on a search results page, thereby cutting a huge portion of the searching public who are satisfied with the topmost listed offering.

Stability of the media content in any returned result is a great factor in pushing it higher in the page ranks. If there are many ways to use this content in many possible configurations, other webpages will simply link to it, giving traffic indirectly and with no extra cost. This is called back-linking, and its most profitable examples are online encyclopedias and marketplaces.

These transparent, orthodox methods are classified as White Hat techniques, where the webmaster complies with the guidelines of the targeted search provider, for the reason that they are offering legitimate media content, products and/or services. This is completely separate from the Black Hat techniques that include submission of web pages with irrelevant keywords and undesirable content embedded in them. These web pages may or may not be host to excessive advertisement, phishing, malware, or viruses, and the wanted result is simply huge traffic at a specific point in time.

Black hat techniquesBlack hat techniques are often like guerrilla attacks, and are easy to spot due to their blatant presentation and confusing content. These media are often only temporarily available to the searching public, before wariness and improved algorithms push these malicious websites down the page rankings, or the media creator has met his required quota and removed the content on his or her own.

Those are just some of the strategies used today. Methods are constantly being refined, updated and streamlined to exclude additional work from webmasters. Most heavy-lifting are being done by search providers themselves to avoid unwanted media from showing up in the search results, as a reaction to the myriad of spam or malware that unavoidably gets created by enterprising individuals searching for heavy traffic in a highly uncensored web.

Access to actual usable results is easy for the casual internet user who often takes for granted the thousands of hours poured by thousands of search specialists. All these efforts are just for the optimization of a single tool for a wanted outcome: traffic, which in itself, is just another tool designed for the purpose to sell. With the end goal of attracting enough internet users to a website, the best tool will be the most ubiquitous one, the Search function, which has now risen to prominence along with the world going mobile.

Lanyards: Different Uses and Styles

Lanyards can be seen everywhere and they have been indispensable items for so many people. They can be used to carry important things that have to be handy all the time. Lanyards are normally worn on the neck or wrist to prevent things from being lost and to make sure they are always visible. Perhaps the most common use of lanyards is to hold IDs, but they can also be used to hold a whistle, mobile phone, small gadgets, etc.

A Brief History

landyardLanyard came from the term “laniere,” a French word meaning thong or strap. It is said that its history dates back to the 17th century during which it was first used as a nautical word that means a line or rope that can hold something to the vessel or boat. Seafarers also used lanyards to hold important things while sailing. During the 19th century, lanyards functioned as a cord for securing weapons, making them especially useful during war. It was used to carry pistols and to indicate rank.

Modern-Day Use

These days, lanyards are usually worn around the neck by almost everyone. Depending on their functions, they can also be worn around the wrist or connected to a purse. Using a lanyard has been proven as the most effective and simplest way of keeping things secured and within reach. Lanyards have different uses, but its primary function is to hold items such as IDs and badges, keys, and small electronic gadgets. To Know More Uses Of Landyards Visit :

In camping, lanyards are used to hold camping gear, knives, or a compass. They are also useful to air-dry washed utensils hanging from tree branches. Likewise, they can be used in the kitchen to hang many objects such as bottle openers and can openers.

Scoubidou, the art of lanyard-making, has become an extremely well-known art among kids who join scouting associations as well as summer camps.

Lanyards have various styles and the primary ones are the following:

1.Cord Lanyards

These are among the most affordable lanyards. They are best used for ID cards and badges. Their string is made  from polyester, nylon, or cotton. Usually, this type of lanyard has a slide size adjuster at the top, behind the neck.

2.Flat or Ribbon Lanyards

Made from flat polyester, nylon, or cotton and most used in custom printed lanyards.

3.Tube Lanyards

These have a narrow width and often resemble a shoelace in terms of design. Only text can be printed on these lanyards, mainly due to their size.

4.Woven Lanyards

These are made from heavy-duty materials, so they are built to last longer.

5.Bead Lanyards

They can either be made from metal or plastic. Perhaps the most famous beaded lanyards are the ones with metals because they can be considered as a jewelry piece. Most of the time, they are worn by women as an accessory. To make these lanyards, they are designed with various types of beads like crystal or glass.

6.Breakaway and Non-breakaway Lanyards

These are lanyards that have adjustable cords. Breakaway lanyards have stretchable cords, which can be detached through the use of force. This is mainly for security purposes in case lanyards get stuck in moving machines. On the other hand, non-breakaway lanyards are non-elastic and firm.

Today, lanyards can be personalized according to one’s needs and preferences. Aside from holding items, lanyards can be used to promote a company by having the name and logo printed on them. Still, if you’re a seafarer or you have to keep certain weapons within reach (assuming you’re in the military), you could opt to use these accessories as well – much like your forefathers did.