 |
| Harvest moon over the Ottawa River |
Jim Elder
Ottawa, Canada
email
Sand & Dunes
Background
Aeolian dunes and sandstone: Overview (intro, including animations)
Strata dip and thickness: True and apparent
Methods
Making pinstripe laminae visible in dry sand (a refinement of Bagnold's water seep method)
Measuring cross-sectional profiles of dune features (using the shadow of a straight-edge)
Detecting subsurface slipface shear (using a sand column of contrasting colour)
Making air flow visible (using simple streamers)
Making sand flow visible using an adapted Hele-Shaw cell
Measuring dip (eg., angle of repose)
Photographic reference scale (for scale, colour, and perspective)
Protecting photographic gear from blowing sand
Observations & Interpretations
Sand micrographs (photos of sand grains)
Air flow in the lee of a dune (recirculation cell)
Cornice deposit (grainfall lee of the brink)
Grainflow (slipface avalanche deposits)
Numerical Models
Dune field morphology (model of migrating bedforms)
| 2005 Jan | Hele-Shaw Cell: Avalanche Segregation and Stratification |
| 2004 Apr | Observations of an Active Dune (including a video of a sandstorm) |
| 2003 Mar | A Deformation Feature in Grand Gulch |
Utah
| 2010 Dec | Lizards of southeast Utah |
| 2008 May | Ravens in Aerobatic Flight |
| 2008 Jan | Bentonite (time lapse photography of drying bentonite) |
| 2005 Mar | Basque Sheepherder Inscriptions |
| 2004 Dec | Multi-angle “3D” Photographs of Some Utah Landscapes (Escalante Canyon, The Thumb) |
Photography
| 2010 Nov | Adapters for afocal optical coupling (photos through microscopes, telescopes, binoculars) |
| 2010 Nov | Measuring resolution (eg., of a microscope or camera), using Airy pattern, FFT, MTF50 |
| 2010 Nov | Review: MicroscopeNet V434B stereomicroscope |
| 2008 Jan | Review: Nikon Coolscan V slide scanner, VueScan software |
| 2007 Nov | Photographic Reference Scale |
| 2006 Oct | Comparison of some Ottawa photofinishers (4x6 prints) |
| 2004 Oct | Notes on making multi-angle '3D' photographs (including javascript for Photoshop and web display) |
| 2004 Jul | Dynamic range of photographs |
Miscellaneous
| 2011 Dec | Review: Computer USB Headsets |
| 2007 Sep | Six Steps to Survival (1955, 'How to survive nuclear war'; US Civil Defense Authority) |
| 2007 Jan | Canoeing the Rideau Canal and Trent-Severn Waterway |
| 2006 Dec | Charts & Figures from "An Inconvenient Truth" |
| 2006 Dec | Emission Spectra of Some Compact Fluorescent Lamps (CFL Bulbs) |
| 2006 Oct | Power Consumption of Some Household Appliances |
| 2006 Feb | Powering a Dell Inspiron 6000 with a Low-Cost Inverter |
| 2004 Aug | Two Mile Time Machine (climate history deduced from Greenland ice cores) |
| 2000 Oct | Varietal Features of Wine (an analysis of wine reviews) |
| 2000 Jul | Ottawa River wind conditions (open weather data) |