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The Geological Record of Ocean Acidification

A rather worrisome paper has just been published in Science magazine. The authors conclude:

[T]he current rate of (mainly fossil fuel) CO2 release stands out as capable of driving a combination and magnitude of ocean geochemical changes potentially unparalleled in at least the last ~300 [million years] of Earth history, raising the possibility that we are entering an unknown territory of marine ecosystem change.

An excellent summary is available on Ars Technica (which is where I first read about this paper).  The paper is B. Hönisch et al, ‘The Geological Record of Ocean Acidification’, Science, vol. 335, no. 6072, pp. 1058–1063, Mar. 2012. DOI: 10.1126/science.1208277.

On the plus side, reading about this research has given me more enthusiasm to finish insulating our bedrooms this weekend!

Where to make notes whilst learning a new programming language

For the past few days I've been teaching myself JavaScript for a PhD project. I'm using the excellent book "JavaScript: The Good Parts" by Douglas Crockford.  To begin with, I took notes in my hand-written note book.  But that was slow and clunky.  So I started making notes in Google Docs.  But that doesn't have syntax highlighting.  So it finally dawned on me: the best place to make notes whilst learning a new language is in code!  This feels so blindingly obvious now that I feel dumb mentioning it but it took me a little while to figure out.  Of course, we all tinker with code snippets whilst learning a new language.  But I'm now trying to get into the habit of creating a new file for each topic, and to put lots of comments in the code to explain each new language feature that I learn.  The code will be my (runnable) notes.

For example, here's my file on the topic of function invocation:

Making graphs for websites and web apps

I've been doing a little research into creating interactive graphs on web pages.  Some quick notes from my research (this isn't meant to be an exhaustive list by any means):

Gas consumption 2007-2011

I've finally gotten round to plotting our gas consumption on a graph. I'm not expecting a measurable drop in our consumption yet. We finished insulating our living room in July 2011 and I'm only just getting round to insulating our bedrooms (Feb 2012). We installed a new condensing gas boiler and solar thermal in July 2011. But we also had a baby in August 2011 so we've had the heating on far more than normal for the last quarter of 2011!

Temperature data from the Heathrow MetOffice weather station

What does this data tell us? And why did it take a fair amount of effort to plot our gas consumption?

Smart Meter Disaggregation

This blog entry is part of a series of posts introducing the topic of smart meter disaggregation.  In previous posts we've looked at the wider reasons for wanting to reduce energy consumption and we've taken a brief look at smart meters.  In the following blog post, I want to introduce the concept of smart meter disaggregation, also known as "non-intrusive load monitoring" or NILM for short1.  The main aim of smart meter disaggregation is to infer two things from a smart meter signal: 1) which appliances are active in the signal and 2) how much energy has each device consumed.  This blog post will summarise the arguments for disaggregation and we'll look at some of the main challenges.

Dimmable LED down lights

Our kitchen is currently lit with 10 × 50 watt tungsten lamps. Yes: that's a total of 500 watts. Which is utterly obscene and I feel distinctly uncomfortable just thinking about it. We want to replace these tungstens with LEDs, hence reducing the power required to light the kitchen by a factor of 10 or so. We have several requirements:

  • Must be dimmable down to 5% or 1% (some LEDs only dim to 60%)
  • Must produce enough light to fill the kitchen
  • Must produce a warm, cosy light
  • Must produce a light with a high enough colour rendering index to mean that skin looks like skin and not like pale plastic

This post is basically a collection of notes recording my research into dimmable LEDs.

Getting the Linux 1-wire file system owfs to work

I followed the installation instructions on the Ubuntu wiki but got stuck on the line where we try to get owfs to talk to the 1-wire network.  This worked for me:

sudo /opt/owfs/bin/owfs u -m /var/lib/1wire

I have a Dallas Semiconductor DS1490F 2-in-1 Fob, 1-Wire adapter.  Also, after installing, I found that the Navitron forum has a discussion on owfs.

All I want to be able to do is log temperature data to a text file.  I think I'll write a simple C++ app to log the temperature data to a text file and then use gnuplot to plot graphs.

Why bother to reduce energy consumption

This blog entry is part of a series of posts introducing the topic of smart meter disaggregation.  This specific post looks at the wider reasons for reducing energy consumption.  In other words, this post explains some of the reasons which keep me up at night when I'm not distracted by work! The reasons for reducing energy consumption typically fall into one of two categories: financial and environmental.  We'll focus mostly on the consumption of electricity but the arguments are mostly applicable to the consumption of all sorts of energy.

Financial reasons

There's been a lot of coverage in the press recently about high energy prices.  In January 2012, for example, the Citizens' Advice Bureau stated that 43% of people are worried that they can't afford their next fuel bill.  The following plot shows average annual domestic electricity prices in the UK from 1994 to 2011 (data from DECC, 2011).

Average annual domestic electricity prices in the UK.Average annual domestic electricity prices in the UK.

Electricity prices have risen from 2004 to today; but, when compared to data from the 1990s, today's prices are not quite as earth-shatteringly high as some news papers would have us believe.

What has caused the 35% price rise (in real terms) from 2003 to 2011?  I'm no expert but let's discuss two datasets which shed some light on what's going on.

Planning to insulate bedrooms this weekend

This weekend my wife and 5-month old daughter are going up North so I'm going to take the opportunity to insulate our two bedrooms. In this post I describe in detail my plans for insulating the walls of our bedrooms and also attempt to calculate how much carbon and cash the insulation will save us.

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