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Comment A Si mono-layer will grow a natural oxide fast (Score 5, Interesting) 67

I would be a little concerned that the silicon mono-layer would grow a natural oxide very fast and thus consume the silicon?

The solution in a HEMT transistor is cool in this respect. It is using an un-doped IV-V semiconductor next to a highly doped layer and excess carriers will form a two-dimensional electron gas at the interface. The carriers will move along the surface of the un-doped semi-conducter that since it is un-doped have better mobility and fewer defects than doped material. It must be something along this property they try to re-create with a silicon mono-layer.

Earth

First Measurement of Magnetic Field In Earth's Core 34

An anonymous reader writes "A University of California, Berkeley, geophysicist has made the first-ever measurement of the strength of the magnetic field inside Earth's core, 1,800 miles underground. The magnetic field strength is 25 Gauss, or 50 times stronger than the magnetic field at the surface that makes compass needles align north-south. Though this number is in the middle of the range geophysicists predict, it puts constraints on the identity of the heat sources in the core that keep the internal dynamo running to maintain this magnetic field."

Comment Re:If it is the SIM card disabling the warning?? (Score 1) 109

If that is the case, it must be specified how a SIM card request this blocking from the phone. Otherwise this is not likely to work between different manufacturers of phones and SIM cards. If there is a specified way of doing this it must be within the GSM protocol to do so.

Alternatively this is a behavior specified by certain network operators who buy phones and SIM cards in bulk and mandate an in-official spec extension from both the SIM card and the phone manufacturer.

In the latter case I think the problem is with the operator. You cannot blame Nokia, Motorola, Samsung, Apple etc., from making business with AT&T, Vodafone, Hutchinson and the like. If an extra feature is a requirement for selling to these operators in the first place what are you to do? The customer is always right and in the subsidized markets the customer is the operator and not the punter using the phone.

Comment If it is the SIM card disabling the warning?? (Score 3, Insightful) 109

Although the GSM specifications say that a phone should pop up a warning when it connects to a station that does not have encryption, SIM cards disable that setting so that alerts are not displayed. Even though the GSM spec requires it, this is a deliberate choice on the cell phone makers, Paget said."

I am not sure I understand the above text. If it is the SIM card disabling the setting, why is this then labeled a deliberate choice by the cell phone makers?

Also I have seen at least on numerous Nokia mobile phones that an icon in the display notify you at least in some instances when encryption is disabled. (This happen quite frequently in e.g. China).

Comment Re:noise floor? (Score 1) 253

Could you elaborate on your claim that a reciever with ~0dB noise figure can detect a signal 15 times smaller than a reciever with ~1dB noise figure? I would expect around 1dB improvement in performance.

You are talking about the noise figure of the reciever and that will differ between handsets as will the reciever algorithms re-creating the transmitted information from the decoded signal.

For a given standard one implementation might require 3dB s/n to reach a given BER but other implementations might need 2dB or 4dB depending on the amount of signal processing and the quality of the algorithms used. For a given sensitivity you can then design your receiver with higher noise figure if your algorithms are better or you can live with lower baseband performance if you design the analogue front-end with lower noise.

You write: "the minimum detectable signal is often defined as the point where the signal power equals the input referred noise power.". This will be the case for a system and an algorithmic implementation where you can detect a signal with 0dB s/n. For systems with coding gain you will typically be able to detect signals with negative s/n and in WCDMA mode a phone is likely to be able to decode a signal with -20dB s/n.

Cellphones

Nokia Trades Symbian For MeeGo In N-Series Smartphones 184

An anonymous reader writes "Nokia announced that moving forward, MeeGo would be the default operating system in the N series of smartphones (original Reuters report). Symbian will still be used in low-end devices from Nokia, Samsung, and Sony Ericsson. The move to MeeGo is a demonstration of support for the open source mobile OS, but considering the handset user experience hasn't been rolled out and likely won't be rolled out in time for its vague June deadline outlined at MeeGo.com, could the decision be premature?"
Math

First Self-Replicating Creature Spawned In Conway's Game of Life 241

Calopteryx writes "New Scientist has a story on a self-replicating entity which inhabits the mathematical universe known as the Game of Life. 'Dubbed Gemini, [Andrew Wade's] creature is made of two sets of identical structures, which sit at either end of the instruction tape. Each is a fraction of the size of the tape's length but, made up of two constructor arms and one "destructor," play a key role. Gemini's initial state contains three of these structures, plus a fourth that is incomplete. As the simulation progresses the incomplete structure begins to grow, while the structure at the start of the tape is demolished. The original Gemini continues to disassemble as the new one emerges, until after nearly 34 million generations, new life is born.'"

Comment Re:Seems odd... (Score 1) 546

I get your point.

It might be possible to maintain a "gcc-light" compiler written fully in C and then have the gcc build scripts completing this boot-strap compiler first. The gcc-light do not need to be fast or effective since it will only be used for boot-strapping. It might even be possible to make it as a pre-processor converting c++ into C.

Earth

Aral Sea May Recover; Dead Sea Needs a Lifeline 131

An anonymous reader writes "It's a tale of two seas. The drying up of the Aral Sea is considered one of the greatest environmental catastrophes in history, but the northern sector of the sea, at least, is showing signs of life. A dam completed in 2005 has increased the North Aral's span by 20 percent, and birds, fish, and people are all returning to the area. Meanwhile, the Dead Sea is still in the midst of precipitous decline, since too much water is being drawn out of the Jordan River for thirsty populations and crops. To keep the sea from shrinking more, scientists are pushing an ambitious scheme called the 'Red-Dead conduit,' which would channel huge amounts of water from the Red Sea to the Dead Sea. However, the environmental consequences of such a project may be troubling."
Image

George Washington Racks Up 220 Years of Late Fees At Library 146

Everyone knows that George Washington couldn't tell a lie. What you probably didn't know is that he couldn't return a library book on time. From the article: "New York City's oldest library says one of its ledgers shows that the president has racked up 220 years' worth of late fees on two books he borrowed, but never returned. One of the books was the 'Law of Nations,' which deals with international relations. The other was a volume of debates from Britain's House of Commons. Both books were due on Nov. 2, 1789."

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