There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

Three parallel algorithms for classical molecular dynamics are presented. The first assigns each processor a fixed subset of atoms; the second assigns each a fixed subset of inter-atomic forces to compute; the third assigns each a fixed spatial region. The algorithms are suitable for molecular dynamics models which can be difficult to parallelize efficiently—those with short-range forces where the neighbors of each atom change rapidly. They can be implemented on any distributed-memory parallel machine which allows for message-passing of data between independently executing processors. The algorithms are tested on a standard Lennard-Jones benchmark problem for system sizes ranging from 500 to 100,000,000 atoms on several parallel supercomputers--the nCUBE 2, Intel iPSC/860 and Paragon, and Cray T3D. Comparing the results to the fastest reported vectorized Cray Y-MP and C90 algorithm shows that the current generation of parallel machines is competitive with conventional vector supercomputers even for small problems. For large problems, the spatial algorithm achieves parallel efficiencies of 90% and a 1840-node Intel Paragon performs up to 165 faster than a single Cray C9O processor. Trade-offs between the three algorithms and guidelines for adapting them to more complex molecular dynamics simulations are also discussed.

Fast parallel algorithms for short-range molecular dynamics

다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

[신간의 별자리x] 우리/미술, 그리고 ‘슬픔의 박물관’

In the last 10 years the field of molecular diagnostics has witnessed an explosion of interest in the use of nanomaterials in assays for gases, metal ions, and DNA and protein markers for many diseases. Intense research has been fueled by the need for practical, robust, and highly sensitive and selective detection agents that can address the deficiencies of conventional technologies. Chemists are playing an important role in designing and fabricating new materials for application in diagnostic assays. In certain cases assays based upon nanomaterials have offered significant advantages over conventional diagnostic systems with regard to assay sensitivity, selectivity, and practicality. Some of these new methods have recently been reviewed elsewhere with a focus on the materials themselves or as subclassifications in more generalized overviews of biological applications of nanomaterials.1-7 We intend to review some of the major advances and milestones in the field of detection systems based upon nanomaterials and their roles in biodiagnostic screening for nucleic acids, * To whom correspondence should be addressed. Phone: 847-4913907. Fax: 847-467-5123. E-mail: chadnano@northwestern.edu. Nathaniel L. Rosi earned his B.A. degree at Grinnell College (1999) and his Ph.D. degree from the University of Michigan (2003), where he studied the design, synthesis, and gas storage applications of metal−organic frameworks under the guidance of Professor Omar M. Yaghi. In 2003 he began postdoctoral studies as a member of Professor Mirkin’s group at Northwestern University. His current research focuses on the rational assembly of DNA-modified nanostructures into larger-scale materials.

/pdf/nanostructures-in-biodiagnostics-5553cs9yqw.pdf

Nanostructures in Biodiagnostics

Method and system for fabricating an electrical interconnect capable of supporting very high current densities (10 6 –10 10 Amps/cm 2 ), using an array of one or more carbon nanotubes (CNTs). The CNT array is grown in a selected spaced apart pattern, preferably with multi-wall CNTs, and a selected insulating material, such as SiO w or Si u N v , is deposited using CVD to encapsulate each CNT in the array. An exposed surface of the insulating material is planarized to provide one or more exposed electrical contacts for one or more CNTs.

Carbon nanotube interconnect

Bulk indium antimonide (InSb) is an III–V semiconductor compound that is widely used to detect infrared (IR) signal of wavelength from 1 um to 5.5 um. InSb nanowire, with huge exciton Bohr radius and small band gap, has great potential in optoelectronics applications. However, IR detector based on InSb nanowire has never been reported due to the limitation of growth technique and the ambiguity of its detection principle. In this paper, IR detector based on a single InSb nanowire will be introduced. InSb nanowires were grown by a vapor-liquid-solid (VLS) approach using InSb powder source and gold catalyst. Stoichiometric nanowires with diameters in the 10–35 nm range and tens of microns long have been obtained. The structure of the InSb nanowire detector consists of an InSb nanowire connecting an Au and a Cu electrode to form a Schottky photodiode, which can separate the photo-generated electron-hole pairs in order to generate photocurrent. An InSb nanowire IR photodetector with an individual InSb nanowire was demonstrated to detect IR signal at room temperature. High quantum efficiency and low dark current were obtained. The InSb nanowires may become significant building blocks for future nano-optoelectronics.

Infrared detection using an InSb nanowire

Synthesis of ZnTe nanostructures by vapor–liquid–solid technique

We have fabricated a sensor array consisting of 32 sensor elements with pristine, doped and metal-loaded single-wall carbon nanotubes as sensing materials. The sensor elements consist of interdigitated electrodes with varying finger widths and gaps. The chemiresistor-type sensors provide a significant response to formaldehyde at concentrations down to 10 ppb in air with rapid response and recovery times.

http://iopscience.iop.org/article/10.1088/0957-4484/22/5/055502/pdf

A carbon-nanotube-based sensor array for formaldehyde detection

A comprehensive continuum model is presented for the analysis of high-density plasma reactors widely used in semiconductor processing. The model couples plasma transport, neutral species dynamics, gas flow, heat transfer, and plasma power coupling from an external source. The governing transport equations are solved along with Maxwell's equations for a multicomponent, multi-temperature system with inductively coupled power deposition. The model and code are applied to a nitrogen discharge in an inductively coupled plasma reactor, and the predictions agree well with the experimental data. The effect of self-consistent modeling of gas flow and gas heat transfer is systematically examined and it is found to affect plasma density and uniformity at low pressures.

http://jes.ecsdl.org/content/146/7/2705.full.pdf

Meyya Meyyappan

Papers

Carbon nanotube interconnect

Infrared detection using an InSb nanowire

Synthesis of ZnTe nanostructures by vapor–liquid–solid technique

A carbon-nanotube-based sensor array for formaldehyde detection

A Continuum Model for the Inductively Coupled Plasma Reactor in Semiconductor Processing