nanoHUB

nanoHUB.org

The nanoHUB.org logo
Type of site	Scientific research support
URL	www.nanohub.org
Commercial	No
Launched	2002

nanoHUB.org is a science and engineering gateway comprising community-contributed resources and geared toward education, professional networking, and interactive simulation tools for nanotechnology.^[1] Funded by the United States National Science Foundation (NSF), it is a product of the Network for Computational Nanotechnology (NCN). NCN supports research efforts in

.

History

The Network for Computational Nanotechnology was established in 2002[2] to create a resource for nanoscience and nanotechnology via online services for research, education, and professional collaboration. Initially a multi-university initiative of eight member institutions including

, NCN now operates entirely at Purdue.

The US National Science Foundation (NSF) provided grants of approximately $14 million from 2002 through 2010, with principal investigator Mark S. Lundstrom.^[3] Continuing US NSF grants have been awarded since 2007 with principal investigator Gerhard Klimeck and co-principal investigator Alejandro Strachan, with total funding of over $20 million.^[4]

Resources

The Web portal of NCN is nanoHUB.org and is an instance of a HUBzero hub. It offers simulation tools, course materials, lectures, seminars, tutorials, user groups, and online meetings.^[5][6] Interactive simulation tools are accessible from web browsers and run via a distributed computing network at

Main resource types:[8]

• Interactive simulation tools for nanotechnology and related fields
• Course curricula for educators
• News and events for nanotechnology
• Lectures, podcasts and learning materials in multiple formats
• Online seminars
• Online workshops
• User groups
• Online group meeting rooms
• Virtual Linux workspaces that facilitate tool development within an in-browser Linux machine

Simulation tools

The nanoHUB provides in-browser simulation tools geared toward nanotechnology, electrical engineering, materials science, chemistry, and semiconductor education. nanoHUB simulations are available to users as both stand-alone tools and part of structured teaching and learning curricula comprising numerous tools. Users can develop and contribute their own tools for live deployment.

Examples of tools include:^[9]

SCHRED

calculates envelope wavefunctions and the corresponding bound-state energies in a typical Metal-Oxide-Semiconductor (MOS) or Semiconductor-Oxide-Semiconductor (SOS) structure and a typical SOI structure by solving self-consistently the one-dimensional (1D) Poisson equation and the 1D Schrödinger equation.

Quantum Dot Lab

computes the

eigenstates

of a particle in a box of various shapes including domes and pyramids.

Bulk Monte Carlo Tool

calculates the bulk values of the electron

average energy and electron mobility

for electric fields applied in arbitrary crystallographic direction in both column 4 (Si and Ge) and III-V (GaAs, SiC and GaN) materials.

Crystal Viewer

helps in visualizing various types of

Buckyball

) can be viewed using this tool.

Band Structure Lab

computes and visualizes the

nanowires for various materials, growth orientations, and strain conditions. Physical parameters such as the bandgap and effective mass

can also be obtained from the computed band structures.

nano-Materials Simulation Toolkit

uses molecular dynamics to simulate materials at the atomic scale.

DFT calculations with Quantum ESPRESSO

uses density functional theory to simulate the electronic structure of materials.

Infrastructure

Rappture Toolkit

The Rappture (Rapid APPlication infrastrucTURE) toolkit provides the basic infrastructure for the development of a large class of scientific applications, allowing scientists to focus on their core algorithm. It does so in a language-neutral fashion, so one may access Rappture in a variety of programming environments, including C/C++, Fortran and Python. To use Rappture, a developer describes all of the inputs and outputs for the simulator, and Rappture generates a

Jupyter notebooks

To complement the existing Rappture GUI tools within nanoHUB, the more recent browser based Jupyter notebooks are also available on nanoHUB, since 2017. Jupyter in nanoHUB offer new possibilities using the existing scientific software, and most notably all Rappture tools, within nanoHUB with the notebooks of interspersed code (e.g. Python, text, and multimedia.

Workspaces

A workspace is an in-browser Linux desktop that provides access to NCN's Rappture toolkit, along with computational resources available on the NCN, Open Science Grid, and TeraGrid networks. One can use these resources to conduct research, or as a development area for new simulation tools. One may upload code, compile it, test it, and debug it. Once code is tested and working properly in a workspace, it can be deployed as a live tool on nanoHUB.

A user can use normal Linux tools to transfer data into and out of a workspace. For example, sftp [email protected] will establish a connection with a nanoHUB file share. Users can also use built-in WebDAV support on Windows, Macintosh, and Linux operating systems to access their nanoHUB files on a local desktop.

Middleware

The

connections to the execution host on which an application session is running. Instead of using the port router to set up a separate channel by which a file import or export operation is conducted, it uses VNC to trigger an action on the browser which relays a file transfer through the main nanoHUB web server. The primary advantage of consolidating these capabilities into the web server is that it limits the entry point to the nanoHUB to one address: www.nanohub.org. This simplifies the security model as well as reduces on the number of independent security certificates to manage.

One disadvantage of consolidating most communication through the web server is the lack of scalability when too much data is transferred by individual users. In order to avoid a network traffic jam, the web server can be replicated and clustered into one name by means of DNS round-robin selection.

The backend execution hosts that support Maxwell can operate with conventional Unix systems, Xen virtual machines, and a form of virtualization based on OpenVZ. For each system, a VNC server is pre-started for every session. When OpenVZ is used, that VNC server is started inside of a virtual container. Processes running in that container cannot see other processes on the physical system, see the CPU load imposed by other users, dominate the resources of the physical machine, or make outbound network connections. By selectively overriding the restrictions imposed by OpenVZ, it is possible to synthesize a fully private environment for each application session that the user can use remotely.^[11]

Usage

The majority of users come from academic institutions using nanoHUB as part of their research and educational activities. Users also come from national labs and private industry. As a scientific resource, nanoHUB was cited hundreds of times in the scientific literature, peaking in 2009.^[12][13] Approximately sixty percent of the citations stem from authors not affiliated with the NCN. More than 200 of the citations refer to nanotechnology research, with more than 150 of them citing concrete resource usage. Twenty citations elaborate on nanoHUB use in education and more than 30 refer to nanoHUB as an example of national cyberinfrastructure.^[when?]

nanoHUB-U

The nanoHUB-U ^[14] online course initiative was developed to enable students to study a subject in a five-week framework roughly equivalent to a 1-credit class. No credit is given – quizzes and exams are simple and are intended to be aids to learning rather than rigorous tests for acquired skills. In the spirit of a research university, nanoHUB-U courses aim to bring new advances and understanding from research into the curriculum; in addition, simulation (often from nanoHUB) are heavily included in the courses. Every effort is made to present courses in a way that is accessible to beginning graduate students with a variety of different backgrounds with a minimum number of prerequisites. The ideal nanoHUB-U course is accessible to any students with an undergraduate degree in engineering or the physical sciences. Courses include nanoelectronics, nanoscale materials, and nanoscale characterization. nanoHUB-U courses are now a part of edX.

See also

• Materials informatics
• Integrated computational materials engineering
• Multiscale modeling

References

Further reading

• EDUCAUSE Review, vol. 42, no. 6 - nanoHUB: Community & Collaboration
• Publications related to HUBzero
• Federal Resources for Educational Excellence
• IBM.com: nanoHUB Does Remote Computing Right
• Alan Henry (August 28, 2007). "Scientists Connect at nanoHUB". Appscout. Archived from the original on July 16, 2011.

External links

• Official website