Tag Archives: Daniel Drumm

A new heuristic search strategy to accelerate imaging

7 November 2017:

CNBP researchers Dr Daniel Drumm (lead author pictured) and Prof Andrew Greentree, both at RMIT University, have analysed microscopy in the contexts of Rényi-Ulam games and half-lies, developing a new family of heuristics. Their research is reported in the journal ‘Scientific Reports.’

Journal: Scientific Reports.

Publication titleMicroscopy as a statistical, Rényi-Ulam, half-lie game: a new heuristic search strategy to accelerate imaging.

Authors: Daniel W. Drumm & Andrew D. Greentree.

Abstract: Finding a fluorescent target in a biological environment is a common and pressing microscopy problem. This task is formally analogous to the canonical search problem. In ideal (noise-free, truthful) search problems, the well-known binary search is optimal. The case of half-lies, where one of two responses to a search query may be deceptive, introduces a richer, Rényi-Ulam problem and is particularly relevant to practical microscopy. We analyse microscopy in the contexts of Rényi-Ulam games and half-lies, developing a new family of heuristics. We show the cost of insisting on verification by positive result in search algorithms; for the zero-half-lie case bisectioning with verification incurs a 50% penalty in the average number of queries required. The optimal partitioning of search spaces directly following verification in the presence of random half-lies is determined. Trisectioning with verification is shown to be the most efficient heuristic of the family in a majority of cases.

Exploring small-sized nanoflakes

29 August 2017:

Size-dependent structural and electronic properties of MoSmonolayer nanoflakes, of sizes up to 2nm, have been investigated by CNBP researchers using density-functional theory (DFT). The paper, published in Scientific Reports is accessible online.

Journal: Scientific Reports.

Publication title: A study of size-dependent properties of MoSmonolayer nanoflakes using density-functional theory.

Authors: M. Javaid (pictured), Daniel W. Drumm, Salvy P. Russo & Andrew D. Greentree.

Abstract: Novel physical phenomena emerge in ultra-small sized nanomaterials. We study the limiting small-size-dependent properties of MoS2 monolayer rhombic nanoflakes using density-functional theory on structures of size up to Mo35S70 (1.74 nm). We investigate the structural and electronic properties as functions of the lateral size of the nanoflakes, finding zigzag is the most stable edge configuration, and that increasing size is accompanied by greater stability. We also investigate passivation of the structures to explore realistic settings, finding increased HOMO-LUMO gaps and energetic stability. Understanding the size-dependent properties will inform efforts to engineer electronic structures at the nano-scale.

New Diamond and Nano Carbons conference

1 June 2017:

CNBP was well represented at the 11th International Conference on New Diamond and Nano Carbons, held in Cairns, Australia, 28th May – June 1, 2017.

CNBP Chief Investigator A/Prof Brant Gibson was Co-chair of the conference (pictured) with CNBP researcher Dr Philipp Reineck a contributing speaker, presenting on ‘Bright and photostable nitrogen‐vacancy fluorescence from unprocessed detonation nanodiamonds’.

Also providing a contributing talk was CNBP’s Dr Lindsay Parker, ‘Applications of fluorescent nanodiamonds in cellular molecular tracing.’

Additionally,  CNBP’s Andrew Greentree, Ivan Maksymov, Daniel Drumm, Ashleigh Heffernan, Marco Capelli, Nicole Cordina and Emma Wilson gave poster presentations and Brooke Bacon and Desmond Lau provided administrative and technical support respectively.

The conference spanned research topics from fundamental physical and chemical concepts to applied technologically driven applications with carbon based materials. This including single crystal diamond, nanodiamonds, carbon nanotubes, graphene and other carbon nanostructures.

Electronic transport in Si:P δ-doped wires

Daniel Drumm Low Res Edit 012211 December 2015:

‘Electronic transport in Si:P δ-doped wires’ is the latest paper by CNBP Research Fellow Dr Daniel Drumm, published in the journal Physical Review B.

Abstract – Despite the importance of Si:P δ-doped wires for modern nanoelectronics, there are currently no computational models of electron transport in these devices. In this paper we present a nonequilibrium Green’s function model for electronic transport in a δ-doped wire, which is described by a tight-binding Hamiltonian matrix within a single-band effective-mass approximation. We use this transport model to calculate the current-voltage characteristics of a number of δ-doped wires, achieving good agreement with experiment. To motivate our transport model we have performed density-functional calculations for a variety of δ-doped wires, each with different donor configurations. These calculations also allow us to accurately define the electronic extent of a δ-doped wire, which we find to be at least 4.6 nm.

Further paper information is available online.

CNBP researchers get ‘Fresh’

Fresh-Science-Vic_web29 July 2015:

Summarizing your research and why it matters in one sentence is hard enough! But when you’re in front of a camera, with a microphone and a curious channel 7 reporter looking at you intently, you really do have to be prepared to get your simple message across. This is what CNBP researchers Daniel Drumm and Philipp Reineck learnt quickly at this year’s ‘Fresh Science Victoria’ program, that took place in Melbourne, July 28-29th , 2015.

The ‘fresh’ program, encouraging public and educational outreach from early career researchers, saw two intensive days of activity (July 28-29) for the two CNBPers who:

– had a full outreach training day at Scienceworks
– workshopped their scientific activity into language clearly understandable to a lay audience
– met with people from Channels 7 and 9, The Age, 3AW and Triple M
– explored the different needs of radio vs. print vs. television media
– met Victoria’s Lead Scientist, Leonie Walsh
– worked on inverting their communication thinking to present the global results first
– presented their projects to the public with a sparkler as a timer (Bright Sparks)
– distilled their work into as few a syllables as possible via haiku and limerick
– met some amazing young scientists from around Victoria with a broad set of skills (physio, geomatics, cancer research, biomechanics, and physics)
– presented their work on stage to an audience of high-school students at Melbourne Museum

Further information on Fresh Science – Stories of discovery from early-career researchers around Australia – is available online.

CNBP researcher publishes cover article

Daniel research image2 June 2015:

A new research paper has been published by CNBP researcher Daniel W. Drumm. The article, examining models for a dye-sensitised solar cell, featured on the back cover of the journal Physical Chemistry Chemical Physics.

TITLE: Optical properties of a conjugated-polymersensitised solar cell: the effect of interfacial structure.

Dye-sensitised solar cells (DSSCs) have sparked considerable interest over two decades. Recently, a method of polymer-wire sensitisation was demonstrated; the polymer is suggested to form a hole transport pathway (wire) following initial charge separation. We predict the optical properties of this polymer in various interfacial configurations, including the effects of chain length and attachment to {100} or {101} TiO2 facets. Contrary to most DSSCs, the {100} facet model best describes the experimental spectrum, predicting a relative thickness of 5.7 0.2 mm, although {101} attachment, if implemented, may improve collection efficiency. Long chains are optimal, and stable attachment sites show minimal differences to absorbance in the major solar emission (visible) band. Combinations of {100}, {101}, and pseudo-bulk TiO2 models in threeparameter fits to experiment confirm the relative importance of the {100} facet.

Daniel W. Drumm, A. Bilic, Y. Tachibana, A. Millere and S. P. Russoa
Physical Chemistry Chemical Physics, 17:14489, 2015 DOI: 10.1039/C4CP05290K.

The full article can be downloaded: http://pubs.rsc.org/en/content/articlelanding/2015/cp/c4cp05290k#!divAbstract

Careers in STEM

Daniel Drumm Low Res Edit 012220 May 2015:

CNBP researcher from RMIT, Dr Daniel Drumm undertook a successful outreach session with Year 10 students today, as a guest speaker at a Careers in STEM session at Wheelers Hill Secondary College located in Melbourne.

His topic was ‘The World of Research’, where he discussed his current job, the pathway taken to it, and the research environments that he has experienced.

Nanoparticles, velcro, marbles and a hot glue gun

CNBPat Questacon SciComm event Dec 2014-2

16 December 2014 :Science Communication workshop.
“If you can’t explain it simply, you don’t understand it well enough.” – Albert Einstein.

On December 15-16th, 9 CNBP ECRs from University of Adelaide,  RMIT University, Macquarie University and SAHMRI attended a science communication workshop at the Questacon workshop (Canberra) and were taught the importance of translating their research into lay terms. More specifically, explaining concepts such as the use of nanoparticles for targeted drug therapy to an 8 year old. Its harder than you think and involves the art of scaffolding; i.e. simplifying a concept by using analogies.

The most interactive and fun session of the workshop involved us creating models and physical demonstrations of our research and included us all running around the Questacon workshop to explain current, throwing paper at people as a demonstration of drug delivery, different coloured glow sticks as an analogy for the use of nanoparticles/probes to diagnose pain and the use of lots and lots of velcro and hot glue guns to make “up-scaled” nanoparticles. Think Playschool for scientists.

CNBP were proud to be sponsors of this professional development workshop which was developed by The ARC Centre of Excellence for Electromaterials Science, in partnership with the ARC Centre of Excellence in Convergent Bio-Nano Science and Technology and the ARC Centre of Excellence in Nanoscale BioPhotonics.

The workshop was designed to teach participants how to put their best foot forward in media interviews, community talks and scientific presentations.