Drainage System And Its Importance

Drainage is the disposal of excess water on land (either used in form of storm water). It must be distinguished from flood control which is the prevention of damage as a result of overflow from river. There are two type of system adopted for waste water collection. Separate sanitary and combined system. In separate sanitary system, there is a separate sewer that collects the household, commercial and industrial waste water and dispossess them while a separate sewer collects the storm water and it separately. In the combined system, both the storm water and domestic water are delivered through the same pipe network.

Sanitary sewers should have a self cleaning velocity of (6.1
M / s). This self cleaning velocity is achieved by laying the drain on a steep slope. Manholes should be placed at interval of 100-120m for the purpose of maintaining and servicing of the sewer. It should be noted that waste water in the sewer are typically transported by gravitational force rather than mechanical means (pumping) for convenient sake. This is why in laying sewer pipes; The topography of the area should be well understood.

The storm water flow can be estimated by .278CIA where C is the coefficient of runoff, I is the rainfall intensity and A is the catchment area. C is usually got from table which is a function of factors that affect infiltration. From rainy data I can be estimated.
A can be estimated by using planimeter or superimposing scaled grid paper on the map and note the grid that fall within the boundary of the map. The waste water from industry, commercial centers and domestic uses are usually estimated by knowing the quantity of waste water the users' discharges through the use of questionnaire and personal interview. The population of people and number of industries should be noted for this estimation.

The overall steps in layout sewers include:

  • Establish comprehensive map of the area including road contour, topography and utilities
  • Drains are shown with a single line with arrows for direction
  • Manholes are shown with a dot at all its necessary locations as the junctions and its intermediate point of 100-120m interval
  • Sewers are designed to follow natural topography
  • Sewers are mostly branch network
  • Sewers or drains are usually located along the road
  • Design approach for sewers is as follows;
  • Estimate manning constant and select slope
  • Compute the section factor
  • Get the best hydraulic section either rectangle or trapezoid
  • Check the satisfaction of minimum velocity
  • Addition of adequate freeboard to avoid overflowing

The disposal of the waste water could be treated or not treated. However, the treatment is usually by biological method. The disposal of waste water is of immerse important for economic growth. The treated or untreated waste could be used as a source of irrigation, supplement stream or river flow and could be used as a source of recharge for ground water.

It is obvious in the cities of the developing countries that the most of construction industries do not take note of all the above mentioned process. As a result storm water follows drains that are not specified for them or overflows the drains there by causing erosions. On the other hand, some of the storm water are stagnant in the drains there by becoming a breeding place for mosquitoes and toads. This could result in increase of malaria and water related disease in the vicinity. All this is because; Most government in such cities have not yet understood the important of drainage systems and the role it plays in social- economic development.

Do not Buy an Expensive Personal Organizer – Create Your Own!

Do you often find yourself late for appointments? Do you feel unorganized? Have a hard time finding phone numbers, addresses or other important information when you need it? If so, then you need a personal organizer. A personal organizer system is an ideal way to help you stay organized and keep all of your information in one place. However, personal organizers – both paper-based and electronic – can be very expensive, and they usually contain categories or sections that you do not need.

Fortunately, it's not really necessary to spend a lot of money on a fancy organizer, PDA or smart phone. You can do it yourself and save a lot of money. Here's how you can create your own custom personal organizer that is inexpensive and perfectly meets your needs.

1. Materials you will need:

A. Small loose-leaf binder. You can find these at just about any statutory store, drugstore, discount, or grocery store. Make sure the binder has pockets in the front or back so you can put in a small calculator and your business cards.

B. Loose leaf lined paper. The paper needs to be the same size as the loose leaf binder.

C. Divider tabs.

D. Appointment calendar. These are small booklet-form calendars you can buy, or you may be able to get one for free from your bank or other merchants that offer these to their customers at the beginning of the year.

E. Small Calculator. Very inexpensive these days – sometimes as cheap as one dollar.

2. Create your categories:

A. Next, you will create the categories that you are going to put in your organizer. Common categories used by many people include addresses, telephone numbers, appointments, expenses, projects, to do list, notes, and so forth. You may create any category that suits your needs. Do not be afraid to be original, because this is going to be custom -made just for you.

B. Write the category names in the divider tabs. Place the tabs in the binder, and include several pieces of blank bound paper behind each divider section.

C. Put the calendar in the appointments section. Remove the outer cover first, and then punch holes along the inside crease of the calendar. Make sure the holes you punch are spaced the same as the binder rings.

D. Finally, put the calculator and your business cards in the inside pocket. The calculator will come in handy anytime you need to make calculations at work or when shopping, and your business cards will be readily accessible when you need to give them out.

3. Use it! Start using your new organizer right away. Any system, no matter how good it is, will be of no practical use if it is not used regularly. Get in the habit of writing down all of your business and personal appointments and important dates such as birthdays, anniversaries, holidays, etc. Also, write down the addresses, phone numbers, e-mail addresses, and other contact information for your family, friends and business contacts. Track your expenses, and write your to-do lists. Everything is effectively organized right there in one place to increase your efficiency and productivity.

That's basically it. You have created your own custom personal organizer for a fraction of the cost of the name brand organizer or a PDA. While it may not be as fancy-schmancy as one of the expensive organizer s, it will work just as well. In fact it will probably work better since you created this system just for you. Now, all you have to do is use it faithfully every day. You will be surprised at how well you will stay organized and keep all of your information in one place.

The Importance of Office Telephone Equipment

It may be that your office telephone equipment is, well, let's say a little past its prime!

Perhaps it:

  • Was purchased many years (or even decades!) Ago;
  • Enterprises lots of different makes of equipment that have somehow been patched together to provide your system;
  • Is not entirely reliable or able to support modern functions such as conferencing.

The harsh choice

If any of that sounds familiar, you realistically face two options:
· Do nothing and hope your business telephone system does not generate troubles for you (or sometimes – more troubles);
· Replace it with a new system.

Replacement

A modern business telephony system from a reputable supplier (for example Siemens telephone systems) can typically be installed quickly and there is a range of configurations available to support the needs of the small companies right up to the largest.

Purchasing a new system may provide you not only with a more reliable set of office telephone equipment but it may also allow you to participate in modern communications exchanges with your customers and suppliers.

That may include things such as:

  • Video;
  • Conference calls;
  • Call re-routing and following;
  • Data exchanges;

Making the right choices

Selecting a new system is something that it's easy to get wrong and that is why specialist advice from experts is typically advisable. There are a number of reasons for that, not the least of which is that it's necessary to think a little about the future and to make sure that the selected system is capable of growing and evolving in tune with your business.

Having today's very best system may not be of much use if it's incapapable of expansion in future – it just becomes tomorrow's potential technical dinosaur.

Maintenance

Of course, if your immediate problem is the frequent crises with your existing system, then you may be worried about just keeping things going while you select your new system.

By taking out a maintenance contract with a skilled supplier of telephony services, you may be able to keep the worst at bay and buy yourself a little breathing space.

That may allow you to concentrate on finding a permanent solution to your office telephone equipment predicament.

Purpose of Shaft Grounding Systems in Marine Engineering

Purpose of Shaft Grounding Systems in Marine Engineering

It’s Science 101:

Electricity and water don’t mix.

That maxim is no clearer than in marine engineering, where seawater mixed with the electrical systems of a propeller can cause corrosion, loss of efficiency and system failure.

To completely protect a ship it’s important to electrically ground the ship’s propeller to the hull. Grounding the propeller limits corrosion and damage to the propeller’s shaft, bearings, and gear box.

Every motor-powered marine vessel should have some sort of shaft grounding system installed.

Shaft is Critical

One of the most critical parts in a marine vessel’s propulsion system is the shaft. Shafts that become corroded over time lose their efficiency. An overly corroded shaft can lead to system failure.

A grounding system is important.

That’s because as electricity runs through the engine to the propeller it mixes with water. The combination of the two – called an electro-chemical reaction – causes corrosion to the shaft.

The shaft provides thrust to move the vessel forward.

Shafts that become corroded over time due to electrochemical reactions with seawater lose their efficiency. They become weaker at transferring energy from the vessel’s engine to its exterior propulsion system.

A grounding system is also necessary to protect the drive-motors bearings from electrical damage. Excessive capacitive discharge can lead to electrical bearing failure.

At the same time, corrosion left unchecked can shorten any ship’s lifespan. This may cause maintenance problems too occur sooner than otherwise.

How Does It Work?

The principle behind shaft grounding is fairly simple.

In most marine vessels, propellers driven by electric current create charges along the exposed sections of the prop. A grounding system insures that as small a charge as possible escapes. The system is designed to ground out all electricity in the ship’s hull.

The grounding prevents free-flowing electrons from doing their damage.

As a result, both the propeller and engine are able to run longer and stronger due to less damage. In most cases, each propeller shaft should hold a ground system.

One type of a grounding system uses a layer of metal outside the shaft. This way, any electrochemical potential from seawater will be attracted to the outer layer as opposed to the shaft itself.

Types of Grounding Varies

The best kind of grounding system to use depends on the vessel.

There are different choices and owner can choose.

Some factors include the type of engine, size of the ship and composition of the hull. Also, systems get more complicated depending on the amount of charge handled. At the same time, the number of propellers and engines a vessel has also affects the choice of system.

Consult a Professional

It’s not always possible to prevent 100 percent corrosion on or within a marine vessel. But the importance of shaft grounding systems in marine engineering should not be overlooked.

Talk to a professional for the most current information on the purpose of grounding systems.

How To Turn Your Useless Home PC Into IP Phone PBX?

When we are talking about setting up the IP phone PBX system in our home, the first thing that comes to our mind is where or how to begin. Here, we will discuss at an easy way to turn your home PC into a fully fledged IP phone PBX. Let us first understand what this technology really is.

Installation using the old method:

The old method of installing the asterisk was one of the most awful ways to install the IP phone. Using CLI (command line interface) based interface to do anything is no more a choice, and when we are talking about Linux, that becomes even more painful. This is the single biggest reason why people now think of installing asterisk in their homes nothing short of a nightmare. When this CLI based Linux installation was carried out, it took many dark twists and turns, at the end of the day. There were fundamentally, two teasing things. For a layman, the first one was remembering all those commands and executing them at the right time. Secondly, for installing Linux separately, you also needed to install asterisk, which was nothing short of climbing the Mount Everest.

GUI Based Asterisk:

Now, users do not have to wrestle with the text based command prompt. New packages have included everything in just one CD and you just don’t need to install different software packages in bits and pieces.

There is a GUI based Linux software which solves half the worries related to remembering all the Linux CLI commands. Now ordinary people like you and me can see as well as relate to what is happening on the screen. Secondly, asterisk’s new GUI based version further makes things easy for the users.

They can make all the changes in asterisk through graphic user interface instead of using the command line interface. There are many GUI based asterisk available and most of them are open source like AsteriskNow, Flash in a PBX, and many others.

All these changes have not only made the installation process a lot easier but also reduced the unnecessary headaches which ordinary people had to go through earlier.

We talked about a useless PC on which asterisk work. Anyhow, we will still have a look at the minimum requirements for the computer that can be used for this purpose.

– You need a PC that is x86 with Linux GUI based operating system installed on it.
– The PC should be a minimum Pentium III with 500 MHz of processor.
– There must be one PCI slot available.
– You must have Digium TDM-400P that supports 2 X FXO daughter cards and 2 X FXS daughter cards.
– Your PC must have a sound card installed and working in perfect condition.

Assuming that you already have Linux operating system installed on your PC, we will proceed with the Trixbox installation as this is one of the most common GUI based asterisk in use.

Installing asterisk on your PC using Trixbox

Once you reach the console, login using these details.

Username: root
Password: The one you provided at the time of installation

Once you have successfully been able to log into your system, your system will mention you the DHCP server received IP address. Now you need to give your system a permanent address which you can do by two ways, either through the GUI or by system-config-network.

Upon configuring the IP address you need to restart the service network.

You will need to use your web browser to continue doing the configuration task through the IP that you just assigned.

Now you will need to click on Switch next to User Mode for opening the Admin GUI. Login details provided below.

user: maint
pass: password

Select the Asterisk – PBXconfig from the GUI.

Go to tools – module admin. Here you can select from a list of modules given. Install the ones which you really think of benefit to you.

Now go to setup – extensions – generic sip device to add your first extension.

Now you can enter different phone extensions that you want to use. Many people prefer starting from 200.

What to do next?

Once you have successfully configured all the settings, now you need to have a phone to make and receive calls. But as in this case, you are using your PC. Make sure you have good quality VoIP headset pair with a mic. This will help you make and receive phone calls. Make sure you have enabled voicemail to get the extra benefits. Now you can virtually attach as many phone users as you want. Just make sure to correctly configure it in your GUI based asterisk and do not forget to assign an extension to each new phone user added. The extension would be unique which can only be assigned to one phone user.

Enjoy managing a big network of phones with secure OS like Linux run by asterisk. There does involve some hard work but at the end. You will not need to invest that much amount of money or effort.

To reduce the cost of the whole process and increase the joys, make sure that you have a reliable internet phone service like Vonage, Axvoice or Skype at the backend.

The Growing Demand For Mobile Phone Accessories

How sweet it is to be able to have your family picture as your mobile screen saver. Thanks to the new world of mobile phone accessories. They come in different forms, such as ear phone, hands-free kits, Bluetooth, cell phone cases, holsters, chargers, stickers, hand straps. These are available at all types of prices to suit everybody. A USB drive helps you attach your cell phone to computer system through which you can download your favorite songs and videos to your cell phone.

Cell phone has become one of the most used electronic items in the world today. But cell phones by themselves are not so attractive to buy, so mobile companies are trying to attract customers by providing them state of the art accessories. They actually enhance the functional capacity of the phone. This business has skyrocketed to meet the ever-growing demand of the customers. In fact, the accessories also help in the sales of the handsets. Their appearance is also enhanced by these accessories.

These accessories are really useful either for communication, videos, storing databases, music, gaming, or other purpose. It is also being used for internet browsing and even business documentation. It is even possible to be connected to the world from the very premises of your home. Day by day, the uses of a cell phone are increasing, and with it the demand for accessories is also increasing.

If you already own one, you will know how easy your life has become because of this technology. Mobile phone manufacturers are providing some high-end mobile phone with preloaded accessories as software attachment or as part of the offer with the mobile phones as hardware items to boost the sales. They are cashing in on this huge sales attraction.

The mobile phone manufacturers are also getting into the business of manufacturing accessories, and these are sold in various ranges in the open market. Not only this, the mobile phones are being manufactured in a way that it is technology-friendly and compatible to all kinds of phone accessories. Mobile phone accessories are becoming indispensable to the base product.

The main categories of accessories available are batteries, Bluetooth devices, cables, chargers, covers, hands free, MoPods and speakers.

These accessories can be bought online as well. So now you can buy mobile accessories from anywhere in the world while being in the comfort of your home. But choosing the right online store is a big challenge. Therefore, before buying any mobile phone accessories online, considering the following points can be helpful:

* Consider the prices of several online stores selling cell phones and their accessories to get the best deal.

* Check the payment options whether they have flexible payment option.

* See how fast they can deliver the product.

* Consider the safety and security of the payment options.

* See if the online store is offering great discounts on their products.

It is always a good idea to buy some accessory for your existing phone rather than replacing the phone itself. Today, cell phones and their add-on accessories are readily available everywhere but care must be taken when you buy these because the duplication has also increased manifold because of the massive demand.

Phone Systems For Small Business – 8 Criteria For Evaluating an IP Phone System

Shoretel’s CEO, John Combs, presented a keynote address recently at IT Expo West, providing very relevant advice to IT managers and others buying a voice over IP (VOIP) phone system. He used the MAC iPhone as an analogy, to illustrate how new technology can quickly dominate an industry. In the case of a VOIP business phone system, IP technology is poised to dominate correspondingly over existing analog (TDM) systems.

VOIP telephone systems can greatly increase user adaption rates, leading to improved productivity in an organization. An IP phone system allows the collaborative and reach aspects of unified messaging technology. The VOIP telephone system generally includes features such as teleconferencing, unified messaging (voicemail in email), web collaboration, mobile integration (cell phones), presence (to locate employees quickly), instant messaging, video conferencing and business process integration (customer relationship management, sales, accounting, etc.).

What differentiates one vendor’s small business phone systems from another’s? Mr. Combs suggests a a very structured selection process when choosing office telephone systems with VOIP for business. He proposed 8 evaluation criteria to be used by the evaluation team making the choice of a new VOIP business phone system:

  1. Usability. There must be an onsite demonstration including the exact hardware to be deployed. It is often advisable to have two or more vendors demonstrate side-by-side, or on the other hand to install alternative prototypes at two separate company offices and then exchange systems and locations to find out which one was best.
  2. Reliability. What is the anticipated failure rate, based on actual deployed systems using Bellcore/Telecordia standards? Mr Combs pointed out that academic failure rates are not sufficient for confidence in deploying a new system. You don’t want to the the “guinea pig” for a vendor’s prototype or Beta testing.
  3. Availability. Make certain understand the impact of downtime on the business based on the planned configuration. Count the points of failure are there in the vendor’s configuration?
  4. Scalability. What are the costs should you need to double the planned configuration?
  5. Architecture. What methodology was used to design the system? Was it well thought out or technology patched together from disparate systems and conflicting architectures?
  6. Total Cost of Ownership. Most of the time upfront costs (hardware, network and implementation) amount to only 20% of the complete system expense over the system’s lifecycle. Day-to-day costs (training, move/add/change, system management, network and utilities) can amount to 80% over the system lifetime. What is the case with the systems under consideration?
  7. Vendor Financial Status. Make sure the vendor has a solid balance sheet, or be prepared for support issues should they encounter financial difficulty.
  8. Vendor References. Your team should contact their industry associates for information relevant to the vendors being considered Did they make a wise decision with this vendor? Do they know of other references? How do actual costs compare to vendor estimates? Is it easy for IT staff to support? What about any “raving fans?”

When evaluating to upgrade small business phone systems, the usual choice is a VOIP business phone system. A careful evaluation of each vendor’s offerings and in particular the presence of “raving fans” for any VOIP business phone system are critical in getting all the benefits of VOIP for business.

Basic Components of Cellular Systems

1. Introduction

There are various cellular systems in the world, such as the GSM and CDMA. The design of these cellular systems are complicated but the architecture of most cellular systems can be broken down into six basic components.

In this article, I will illustrate the six basic components that can be found in most cellular systems.

2. Six basic components of Cellular Systems

The architecture of most cellular systems can be broken down into the following six components:

a) Mobile Station (MS)

A mobile station is basically a mobile/wireless device that contains a control unit, a transceiver and an antenna system for data and voice transmission. For example, in GSM networks, the mobile station will consist of the mobile equipment (ME) and the SIM card.

b) Air Interface Standard

There are three main air interface protocols or standards: frequency division multiple access (FDMA), time division multiple access (TDMA) and code division multiple access (CDMA). These standards are basically the medium access control (MAC) protocols that define the rules for entities to access the communication medium.

These air interface standards allow many mobile user to share simultaneously the finite amount of radio channels.

c) Base Station (BS)

A base station is a fixed station in a mobile cellular system used for radio communications with mobile units. They consist of radio channels and transmitter and receiver antenna mounted on a tower.

d) Databases

Another integral component of a cellular system is the databases. Databases are used to keep track of information like billing, caller location, subscriber data, etc. There are two main databases called the Home Location Register (HLR) and Visitor Location Register (VLR). The HLR contains the information of each subscriber who resides in the same city as the mobile switching center (MSC). The VLR temporarily stores the information for each visiting subscriber in the coverage area of a MSC. Thus, the VLR is the database that supports roaming capability.

e) Security Mechanism

The security mechanism is to confirm that a particular subscriber is allowed to access the network and also to authenticate the billing.

There are two databases used for security mechanism: Equipment Identify Register (EIR) and Authentication Center (AuC). The EIR identifies stolen or fraudulently altered phones that transmit identity data that does not match with information contained in either the HLR or VLR. The AuC, on the other hand, manages the actual encryption and verification of each subscriber.

f) Gateway

The final basic component of a cellular system is the Gateway. The gateway is the communication links between two wireless systems or between wireless and wired systems. There are two logical components inside the Gateway: mobile switching center (MSC) and interworking function (IWF).

The MSC connects the cellular base stations and the mobile stations to the public switched telephone network (PSTN) or other MSC. It contains the EIR database.

The IWF connects the cellular base stations and the mobile stations to Internet and perform protocol translation if needed.

3. Conclusion

This article aims to provide an introductory guide to the architecture of a typical cellular system and identify the six basic components found in most cellular systems. This article offers an insight towards how a cellular system is designed although different cellular systems may have variations in their own implementations.

Telephone Systems – An Overview On Operating Principle

A Telephone system is a communication instrument that transmits any voice / sound signals to far by locations by converting these sound signals in waves and receives and reconverts the same waves into sound signals/ voice. The telephone network is extended universally so if you want to talk to someone, you simply need to pick up the telephone system and dial a few digits. You are instantly connected to that person and both of you can have a 2 way conversation.

Telephone systems were first introduced by Graham Bell over one hundred years ago, but it is still works on the same operating principle. To make a call, we need to first pick up the handset. This causes the telephone system to be connected to a routing network. By pressing the numbers present on the touch tone keypad / frequency generator, signals are passed down via phone line to the routing station. Here, each digit is identified as a unique combination of tone frequencies. The specific combination of digits causes a signal to be passed to other telephone systems causing it to ring. When that telephone is picked up, connection between the two telephone systems is achieved.

The ear piece acts as speaker where as mouthpiece acts as a microphone. Sound waves from the user’s voice cause vibration to a thin plastic disc present inside the telephone system. This causes change in the distance between the plastic disk and another metal disk resulting in a varying electric current which is passed through the phone lines. The receiver on the other phone picks up this electromagnet current. These magnets cause diaphragm to vibrate which produces the sound /voice that initiated the current. An amplifier in the receiver end makes it easier to hear. When one of the phones is hung up the electric current get broken resulting in dis-connection of the telephone systems.