The photoelectric effect without photons

Mathematical model of photoelectric effect without photon

Build-up of laser oscillations from quantum noise

Laser oscillation build up from quantum nois

A non-destructive analytic tool for nanostructured materials : Raman and photoluminescence spectroscopy

Modern materials science requires efficient processing and characterization techniques for low dimensional systems. Raman spectroscopy is an important non-destructive tool, which provides enormous information on these materials. This understanding is not only interesting in its own right from a physicist's point of view, but can also be of considerable importance in optoelectronics and device applications of these materials in nanotechnology. The commercial Raman spectrometers are quite expensive. In this article, we have presented a relatively less expensive set-up with home-built collection optics attachment. The details of the instrumentation have been described. Studies on four classes of nanostructures - Ge nanoparticles, porous silicon (nanowire), carbon nanotubes and 2D InGaAs quantum layers, demonstrate that this unit can be of use in teaching and research on nanomaterials.Comment: 32 pages, 13 figure

Formation of Box Canyon, Idaho, by megaflood: implications for seepage erosion on Earth and Mars

Amphitheater- headed canyons have been used as diagnostic indicators of erosion by groundwater seepage, which has important implications for landscape evolution on Earth and astrobiology on Mars. Of perhaps any canyon studied, Box Canyon, Idaho, most strongly meets the proposed morphologic criteria for groundwater sapping because it is incised into a basaltic plain with no drainage network upstream, and approximately 10 cubic meters per second of seepage emanates from its vertical headwall. However, sediment transport constraints, ^4He and ^14C dates, plunge pools, and scoured rock indicate that a megaflood (greater than 220 cubic meters per second) carved the canyon about 45,000 years ago. These results add to a growing recognition of Quaternary catastrophic flooding in the American northwest, and may imply that similar features on Mars also formed by floods rather than seepage erosion

The development of parental preferences in the first two years of life

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45603/1/11199_2004_Article_BF00287413.pd

Gamma-Ray Bursts as a Probe of the Very High Redshift Universe

We show that, if many GRBs are indeed produced by the collapse of massive stars, GRBs and their afterglows provide a powerful probe of the very high redshift (z > 5) universe.Comment: To appear in Proc. of the 5th Huntsville Gamma-Ray Burst Symposium, 5 pages, LaTe

Diverse annual plantings and their contribution to forage yield and soil improvement

Non-Peer ReviewedMulti-species plantings, also known as polycultures, are expected to have several ecosystem benefits based on the varying contributions from different plants. Potential benefits include increased nutrient cycling, increased soil moisture retention, increased forage yield, decreased soil compaction, and decreased weed communities. Local Saskatchewan producers and groups have implemented multi-species plantings with great success, and this project attempts to build on this anecdotal evidence to not only quantify the impact of polycultures, but to also determine what makes a mixture more or less effective in a particular environment. Our preliminary results suggest that increased crop species richness and functional group richness have many benefits including increased biomass production and decreased weed and insect abundance

Does a monetary incentive improve the response to a postal questionnaire in a randomised controlled trial? : the MINT incentive study

Background: Sending a monetary incentive with postal questionnaires has been found to improve the proportion of responders, in research in non-healthcare settings. However, there is little research on use of incentives to improve follow-up rates in clinical trials, and existing studies are inconclusive. We conducted a randomised trial among participants in the Managing Injuries of the Neck Trial (MINT) to investigate the effects on the proportion of questionnaires returned and overall non-response of sending a £5 gift voucher with a follow-up questionnaire. Methods: Participants in MINT were randomised to receive either: (a) a £5 gift voucher (incentive group) or (b) no gift voucher (no incentive group), with their 4 month or 8 month follow-up questionnaire. We recorded, for each group, the number of questionnaires returned, the number returned without any chasing from the study office, the overall number of non-responders (after all chasing efforts by the study office), and the costs of following up each group. Results: 2144 participants were randomised, 1070 to the incentive group and 1074 to the no incentive group. The proportion of questionnaires returned (RR 1.10 (95% CI 1.05, 1.16)) and the proportion returned without chasing (RR 1.14 (95% CI 1.05, 1.24) were higher in the incentive group, and the overall non-response rate was lower (RR 0.68 (95% CI 0.53, 0.87)). Adjustment for injury severity and hospital of recruitment to MINT made no difference to these results, and there were no differences in results between the 4-month and 8-month follow up questionnaires. Analysis of costs suggested a cost of £67.29 per additional questionnaire returned. Conclusion: Monetary incentives may be an effective way to increase the proportion of postal questionnaires returned and minimise loss to follow-up in clinical trials