Technology Update

HDTV stands for High Definition Television, and if you live in the USA, Australia, or
Japan you may already have experienced it. There are three key differences between
HDTV and what’s become known as standard definition TV ie regular NTSC, PAL or
SECAM. The three differences are; an increase in picture resolution, 16:9 widescreen
as standard, and the ability to support multi-channel audio such as Dolby Digital.

The most important aspect of HDTV, and the one which gives it its name is the
increased resolution. Standard definition NTSC broadcasts have 525 horizontal
lines, and PAL broadcasts are slightly better at 625 lines. In both these systems
however, the actual number of lines used to display the picture, known as the active
lines, is fewer than that. In addition, both PAL and NTSC systems are interlaced, that
is, each frame is spit into two fields, one field is the odd-numbered lines and the
other is the even lines. Each frame is displayed alternately and our brain puts them
together to create a complete image of each frame. This has an adverse affect on
picture quality.

HDTV is broadcast in one of two formats; 720p and 1080i. The numbers refer to the
number of lines of vertical resolution and the letters refer to whether the signal is
progressive scan, ‘p’, or interlaced, ‘i’. Progressive scan means that each frame is
shown in its entirety, rather than being split into fields. Both systems are
significantly better quality than either PAL or NTSC broadcasts.

HDTV uses 16:9 widescreen as is its aspect ratio so widescreen pictures are
transmitted properly and not letterboxed or panned and scanned. Dolby Digital
multichannel sound can be broadcast as part of an HDTV signal, so if you have a
surround sound speaker set-up you can use it to listen to TV rather than just DVDs.

To receive an HDTV broadcast you need either a TV with a built-in HDTV tuner or a
HDTV receiver
which can pick-up off the air HDTV channels, or cable or satellite HDTV like. You
also need to live in are where HDTV channels are broadcast or distributed by cable
or satellite.

Currently HDTV is widespread in Japan and is becoming commonplace in the US,
with most major networks distributing HDTV versions of their popular content. The
2005 Superbowl led to a large increase in the demand for Fox Sports HDTV and
cable companies scrambled to add it to their offering in the run up to the game. In
Autralia, HDTV uptake was sluggish initially but has increased significantly since
2003.

The situation in Europe is not so bright. There is only one company broadcasting
HDTV in the whole of Europe, Euro1080, and it has only two HDTV channels, both in
the 1080i format. Euro1080HDe shows major cultural and sporting events to
cinemas and clubs around Europe, while HD1 broadcasts sports, opera, rock music,
and lifestyle programs via satellite to homes in Europe. UK satellite broadcaster, Sky,
which is owned by Fox proprieter Rupert Murdoch, has announced plans to
broadcast some HDTV content in 2006. The BBC has also made noises about
broadcasting HDTV programs (it already films some programs in HD format).

However, it will be a while before HDTV in Europe catches up with the rest of the
world. The controversy created by the confirmation of plans by the UK government
to start switching off analogue transmitters in 2008 showed how many people have
yet to make the switch to DVB-T. That will be used as an argument to show that
there is no appetite in the UK for another major change in TV broadcasting –
particularly as most people think they already have ‘digital TV’ in the form of DVB-T.

Given that television was invented by a Briton, and Europe led the way with PAL for
so long, this is a rather sorry state of affairs.

Kenny Hemphill is the editor and publisher of The HDTV Tuner – a guide to the kit, the technology and the
programming on HDTV.

With the surge in popularity of the Internet, Remote Access Services (RAS) have become widely popular in the IT environment. RAS let you connect to your computer from a remote location, such as your home, to the SLAC network. RAS’s primary function is to let you access files on a server from a remote location. In order to use RAS from a remote location, a RAS client program is required, which is usually built into the most versions of the Windows or PPP client software.

RAS is a built-in feature of Windows NT that enables the users to log in to an NT-based LAN environment using a modem, X.25 connection or WAN link. RAS works with almost all the major network protocols, including TCP/IP, IPX, and Netbeui.

RAS lets a user dial into any network and use any dialup connection just as if it were a network connection. Though it has its own set of disadvantages, like being slower in comparison to a regular network connection.

Once connected to the RAS, you need to follow the usual procedures to access the network. For example, of you want to connect to a drive on the network, use Windows NT 4.0’s My Computer icon from your remote computer, with the map network drive, or explore the network neighborhood, just as if you would explore it from your office PC.

In order to run a program available on the host computer, download and run the executable code on your remote computer. RAS works just like any other network connection, not as a remote control.

Remote Access provides detailed information about remote access, remote PC access, secure remote access, remote internet access and more. Remote Access is the sister site of FTP Site Hosting.

Does temperature and or humidity affect batteries?

Batteries are affected by temperature and or humidity. If batteries are too hot or too cold, then yes batteries will exhibit behaviors that would be incongruent with their normal and designed operating specifications. This is not a manufacturer defect but a consequence of using a battery in an environment that the battery was never designed to be used. Let us refer to this type of environment as a weather extreme.

If a battery is exposed to a weather extreme it may stop working, bulge, bubble, melt, damage your device, smoke, create sparks, create flames, expand, contract, and or even blow-up in very extreme cases.

Weather extremes, where the ambient temperature and the relative humidity of a specific environment are altered beyond the norm may occur almost anywhere and at anytime. Here are a few such examples (this is by no means exhaustive): a weather extreme can occur outside, in a non-temperature controlled room, in a closed bathroom with the shower on, in a closed car on a hot day, in a steam-room or a sauna to name a few places. Altitude also affects batteries, for example above 15,000 feet in non-pressurized cabin. Extreme cold also affects the battery as the internal components expand as direct result to A weather extreme can also occur even when the temperature is well within the range of the devices specification but the relative humidity increases the ambient temperature beyond the norm.

If a device including the battery is exposed to weather extremes for any length of time then there will be an affect; mostly a negative effect on your device and battery.

Why does temperature affect a battery – because batteries are a device that converts chemical energy into electrical energy? A battery is an electro-chemical device. A battery has two electrodes, an anode (the positive end) and a cathode (the negative end). In between the battery’s two electrodes runs an electrical current caused primarily from a voltage differential between the anode and cathode. The voltage runs through a chemical called an electrolyte (which can be either liquid or solid). This battery consisting of two electrodes is called a voltaic cell.

The batteries we use today are simple variations of the early battery or voltaic cell. Today’s battery’s are made up of plates of reactive chemicals separated by barriers, being polarized so all the electrons gather on one side. The side that all the electrons gather on becomes negatively charged, and the other side becomes positively charged. Connecting a device creates a current and the electrons flow through the device to the positive side. At the same time, an electrochemical reaction takes place inside the batteries to replenish the electrons. The effect is a chemical process that creates electrical energy.

When ambient temperature changes occur the electrons within the battery is affected. When an increase in temperature occurs the electrons are excited. A decrease in temperature inhibits electrons. This is a natural reaction on electrons in most systems. Furthermore, the combination of a rapid temperature change and high humidity can cause condensation to form and a potential hazard for your battery and device for that matter.

© Dan Hagopian. You have permission to publish this article electronically or in print, free of charge, as long as the bylines are included with link. Dan Hagopian of http://www.batteryship.com is a known electronics author that specializes in portable power gadgets. His work can be found on the BatteryShip blog at http://www.batteryeducation.com. He frequently writes about pda batteries, ipod batteries, general battery technology for our mobile world, new fuel cell technology and interesting power related inventions. For further information please visit http://www.batteryship.com where you can also find PDA Battery Replacement Kits, iPod battery, iPAQ battery, Clie battery, Palm Battery, Axim battery, Treos, and Blackberries.