Momay's Blog

by: Roberto Sedycias

A digital camera captures images in a digital format, unlike a conventional camera, which captures images using a photographic film.

History:

Using a mosaic photosensor, Eugene F. Lally of the Jet Propulsion Laboratory first showed how still photos could be produced in a digital domain. An engineer at Eastman Kodak, Steve Sasson, used solid-state CCD chips to build a prototype digital camera having a resolution of 0.01 megapixel, and recorded black and white digital images to a magnetic cassette tape. With this prototype model, Steve took the first image in December of 1975 taking 23 seconds to capture it.

In 1988, Fuji DS-1P became the first digital camera that captured images as a computerized file. However, the camera never entered the U.S. market. In 1991, Kodak DCS-100 was the first commercially available digital camera, which used a 1.3 megapixel sensor. With the advancement of technology, modern digital cameras have become multifunctional and are now capable of capturing audio/video and still photographs.

Benefits:

1 - You get superior image quality. Digital cameras can offer good to excellent image resolution.

2 - You get a fair price. A digital camera is reasonably priced and is affordable.

3 - You can transfer the pictures to your laptop. You can easily connect the digital camera to your laptop and transfer the pictures in your hard disk.

4 - You can print in large sizes. Due to its high resolution, pictures can be printed in large sizes by any plotter.

5 - You can email the pictures to your friends. You can send the pictures by email to your loved ones.

6 - You can store the images in CDs or hard disk. Once the pictures are transferred from digital camera to the computer, permanent storage on a CD or hard disk is possible.

7 - You can take the camera in your pocket while you travel. The small size of the digital camera makes traveling with it easy and a pleasure.

8 - You can move in close to your subject. Zoom lenses offer close-ups of your subject with sharp focus. You can take very good close-ups of flowers, bugs, stamps, coins, etc.

9 - You can rework the image in a computer. Any photo editing software can rework the images taken.

10 - You can take good pictures even in low-light situations. Due to flexible over sensitivity or ISO equivalents, digital cameras can easily take detailed pictures even in low-light conditions.

11 - You can take quality still photos of moving objects. Sports and fashion photography can be easily accomplished due to the fast burst rate of digital cameras.

12 - You save money. There is no need of buying photographic films, developing them into negatives and positives. Moreover, the batteries are usually rechargeable lithium-ion batteries, which last a long time.

13 - You can choose as per your needs and fancy. Many models are available like standard digital camera, underwater digital camera, waterproof digital camera, compact digital camera, and the professional digital camera.

Storage Media:

Digital cameras use memory to capture and store images. Some of the storages media used are onboard flash memory, 3.5" floppy disks, video floppy disk, PCMCIA hard drives, CD or DVD, CompactFlash memory cards, Microdrives, Memory Stick, SD/MMC, MiniSD Card, MicroSD Card, XD-Picture Card, SmartMedia, and FP Memory.

Power:

Digital cameras consume a lot of power, which is supplied by powerful, small in size batteries. Batteries are broadly divided into two groups, namely, off-the-shelf and proprietary. Off-the-shelf batteries are like AA, CR2, CR-V3, AAA, and RCR-V3. They are lithium-ion (Li-Ion) or Nickel metal hydride (NiMH) batteries. Standard AA non-rechargeable alkaline batteries either do not work or work for only a very short time in most cameras.

Proprietary batteries are built as per the manufacturer`s custom specifications and are usually available as aftermarket replacement parts. Generally, lithium ion batteries are widely used as proprietary batteries for digital cameras.

About The Author

Roberto Sedycias works as IT consultant for http://www.polomercantil.com.br

This article can also be accessed in portuguese language from page http://www.polomercantil.com.br/camera-digital.php

by: Roberto Sedycias

Cell phone (telefone celular) is a wireless, portable, long-range, electronic telephone, which during travel can seamlessly change antenna connections, from one radio reception cell to another radio reception cell, without dropping or losing the ongoing call.

Besides the standard voice function of a telephone, latest cell phones (telefone celular) have features such as SMS for text messages, MMS for multimedia messages, radio, games, internet connectivity for email, browsing, blogging, music (MP3) playback, memo recording, built-in cameras and camcorders, ringtones, personal organizers, Push-to-Talk (PTT), Bluetooth and infrared connectivity, call registers, streaming video, downloading video, video call, and also serve as wireless modems for PCs that can be connected to the Internet.

The power in a cell phone (telefone celular) is obtained from rechargeable batteries, which can be recharged from the mains, a USB port or a cigarette lighter port in an automobile. Nickel Metal Hydride were the most common types of batteries, which due to the "memory effect" (the user can recharge only when the entire battery is drained off) were replaced by Lithium-Ion batteries, which did not suffer from any memory effect.

Cell phones (telefone celular) came into existence because of the invention of hexagonal cells in 1947, for the base stations by Bell Labs engineers at AT&T. This was further developed during the 1960s by Bell Labs. During a call, the channel frequency could not be changed automatically from one cell (base station coverage area) to another cell (base station coverage area) as the person traveled from the area of one cell to the area of another cell. Amos Joel of Bell Labs invented a breakthrough invention and called it as the `call handoff` by which the channel frequency could be changed automatically from one cell to another cell, during the same call, as the mobile user traveled from one cell to another cell. Due to their heavy construction, these phones were used mainly in automobiles.

The first practical cell phone in a non-vehicle setting, and which could be handheld, was invented by Martin Cooper, the General Manager (Communications Division) of Motorola, who made the world`s first handheld cell phone (telefone celular) call on April 3, 1973.

The technology by which the cell phone (telefone celular) works depends on the mobile phone operator; however, all of them use electromagnetic radio waves, which are in touch with a cell site (base station). The base station is composed of several antennas which are mounted on a pole, tower, or building. Cell sites are spread at a distance of 5 to 8 miles (approx. 8 to 13 km) from each other. The low power transceiver from the cell phone transmits the voice and data to the nearest cell site. During movement, the cell phone will "handoff" the information to other cell site. Mobile phone operators use many technologies to maintain the smooth stream of digitized data from the cell phone to the cell site and vice versa.

The wireless telephone technologies are grouped under heads known as generations, starting from zero generation or 0G. The current generation going on is 4G; however, there are old cell phones (telefone celular) that still operate on 1G, 2G, and 3G technologies. The wireless telephone technologies used in each generation are as given below:

0G: PTT, MTS, IMTS, AMTS, OLT, MTD, Autotel/PALM, ARP

1G: NMT, AMPS/TACS/ETACS, Hicap, CDPD, Mobitex, DataTac

2G: GSM, iDEN, D-AMPS, IS-95/cdmaOne, PDC, CSD, PHS, GPRS, HSCSD, WiDEN, CDMA2000 1xRTT/IS-2000, EDGE (EGPRS)

3G: W-CDMA, UMTS (3GSM), FOMA, TD-CDMA/UMTS-TDD, 1xEV-DO/IS-856, TD-SCDMA, GAN (UMA), HSPA, HSDPA, HSUPA, HSPA+, HSOPA

4G : UMB, UMTS Revision 8 (LTE), WiMAX

Frequency bands: SMR, Cellular, PCS

The impact of cell phone (telefone celular) usage on human health has been of considerable worldwide concern. Research studies in Copenhagen, from the Danish Institute of Cancer Epidemiology, the National Cancer Institute, and the Institute of Cancer Research, do not establish any link between cancer and cell phone usage. However, an intergovernmental agency IARC (International Agency for Research on Cancer) forming part of the World Health Organization of the United Nations, undertook a study of 4,500 users and found a statistically significant link between cell phone usage and tumor frequency. Further research is going on.

Cell phone (telefone celular) usage and driving is a common worldwide phenomenon. Some jurisdictions have banned usage of hand-held phones during driving, but allowed the hands-free fashion of cell phone usage while driving. However, studies have found out that the distraction is caused by the conversation itself; hence, both hand-held and hands-free cell phones contribute towards road traffic accidents. Further studies on cell phone usage and driving are going on.

Nokia Corporation is currently the world`s largest manufacturer of cell phones (telefone celular). Other notable cell phone manufacturers, in alphabetical order, are 3G, Audiovox (now UT Starcom), Benefon, BenQ-Siemens, Fujitsu, High Tech Computer Corporation (HTC), Kyocera, LG Mobile, Motorola, NEC, Panasonic (Matsushita Electric), Pantech Curitel, Philips, Research In Motion, Sagem, Samsung, Sanyo, Sharp, Siemens, Sierra Wireless, SK Teletech, Sony Ericsson, T&A Alcatel, Toshiba, and Verizon.

About The Author

Roberto Sedycias works as IT consultant for http://www.polomercantil.com.br

This article can also be accessed in portuguese language from page http://www.polomercantil.com.br/celular.php

by: Jim Furness

Perhaps the most common application for the use of the data logger in the world today is for temperature logging. The temperature data logger is used in factories, offices, hospitals, museums, road transport, and outdoors for environmental monitoring. Here is an outline of typical temperature data logger applications:

Temperature data logger use in factories

The monitoring and logging of temperature is vital in many manufacturing processes. In the food industry a temperature data logger is often used to ensure that unprocessed food is stored at the correct temperature in cold stores. It is also used in ovens and production lines to ensure the food has been heated to the correct temperature for the required length of time

In the semi conductor industry clean rooms and production processes must be kept at a constant temperature to ensure quality control. Here the temperature data logger is indispensable.

In brick works a temperature data logger is used in the oven through process to ensure that bricks are cured to the correct temperature.

Temperature data logger us in offices

Many companies will position a temperature data logger in main working areas throughout their building to verify that a comfortable temperature is maintained during working hours. Staff will sometimes complain that a room is either too hot, or too cold. A data logger can be used to record the actual temperature so that subjective judgments can be corroborated.

Temperature data logger use in hospitals

Hospitals use many types of data logger for temperature recording. Fridges and freezers where drugs and samples are stored will have a temperature data logger permanently installed. Incubators are also generally monitored for temperature and here a data logger is often used for historical data.

Temperature data logger use in museums and art galleries

In paintings many artefacts are extremely sensitive to temperature. It is common for a temperature data logger to be placed in each room, and often within individual display cases to monitor ambient temperature. In art galleries paintings are very sensitive to temperature. As well as placing a data logger in each room, sometimes a temperature data logger is also fitted within the frame of very old paintings, particularly those painted on wood.

Temperature data logger use in environmental monitoring

In addition to general weather monitoring the temperature data logger is used widely to log temperature over large areas where scientists and researchers need to have exact ground temperature data. Typical examples are glaciers, rain forests, mountain areas, and polar regions. A temperature data logger can also be used to monitor rivers and lakes.

Temperature data logger use in road transport

Sensitive or delicate goods, in particular foodstuffs can often be in transit for many hours or days by road. A data logger can be used to check that goods in refrigerated trucks have been maintained at the correct temperature throughout a journey. In the UK it is now a requirement to use a data logger to record temperature in vehicles used for livestock transportation.

About The Author

Jim Furness is CEO of Omniinstruments Ltd, specialists in data loggers and other instrumentation solutions.

For more information visit us at: http://www.omniinstruments.co.uk

 

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