Publications

An Oxygen-Insensitive Hydrogen Evolution Catalyst Coated by a Molybdenum-Based Layer for Overall Water Splitting

Apr 13, 2017 Angewandte Chemie

For overall water-splitting systems, it is essential to establish O2-insensitive cathodes that allow cogeneration of H2 and O2. An acid-tolerant electrocatalyst is described, which employs a Mo-coating on a metal surface to achieve selective H2 evolution in the presence of O2. In operando X-ray absorption spectroscopy identified reduced Pt covered with an amorphous molybdenum oxyhydroxide hydrate with a local structural order composed of polyanionic trimeric units of molybdenum(IV). The Mo layer likely hinders O2 gas permeation, impeding contact with active Pt. Photocatalytic overall water splitting proceeded using MoOx/Pt/SrTiO3 with inhibited water formation from H2 and O2, which is the prevailing back reaction on the bare Pt/SrTiO3 photocatalyst. The Mo coating was stable in acidic media for multiple hours of overall water splitting by membraneless electrolysis and photocatalysis.
Controlled Surface Segregation Leads to Efficient Coke-Resistant Nickel/Platinum Bimetallic Catalysts for the DryReforming of Methane

Feb 28, 2015 CHEMCATCHEM

Surface composition and structure are of vital importance for heterogeneous catalysts, especially for bimetallic catalysts, which often vary as a function of reaction conditions (known as surface segregation). The preparation of bimetallic catalysts with controlled metal surface composition and structure is very challenging. In this study, we synthesize a series of Ni/Pt bimetallic catalysts with controlled metal surface composition and structure using a method derived from surface organometallic chemistry. The evolution of the surface composition and structure of the obtained bimetallic catalysts under simulated reaction conditions is investigated by various techniques, which include CO-probe IR spectroscopy, high-angle annular dark-field scanning transmission electron microscopy, energy-dispersive X-ray spectroscopy, extended X-ray absorption fine structure analysis, X-ray absorption near-edge structure analysis, XRD, and X-ray photoelectron spectroscopy. It is demonstrated that the structure of the bimetallic catalyst is evolved from Pt monolayer island-modified Ni nanoparticles to core–shell bimetallic nanoparticles composed of a Ni-rich core and a Ni/Pt alloy shell upon thermal treatment. These catalysts are active for the dry reforming of methane, and their catalytic activities, stabilities, and carbon formation vary with their surface composition and structure.
Open Problems : Porting an Explicit Time-Domain Volume-Integral-Equation Solver on GPUs with OpenACC

Apr 2014 Antennas and Propagation Magazine, IEEE

Graphics processing units (GPUs) are gradually becoming mainstream in high-performance computing, as their capabilities for enhancing performance of a large spectrum of scientific applications to many fold when compared to multi-core CPUs have been clearly identified and proven. In this paper, implementation and performance-tuning details for porting an explicit marching-on-in-time (MOT)-based time-domain volume-integral-equation (TDVIE) solver onto GPUs are described in detail. To this end, a high-level approach, utilizing the OpenACC directive-based parallel programming model, is used to minimize two often-faced challenges in GPU programming: developer productivity and code portability. The MOT-TDVIE solver code, originally developed for CPUs, is annotated with compiler directives to port it to GPUs in a fashion similar to how OpenMP targets multi-core CPUs. In contrast to CUDA and OpenCL, where significant modifications to CPU-based codes are required, this high-level approach therefore requires minimal changes to the codes. In this work, we make use of two available OpenACC compilers, CAPS and PGI. Our experience reveals that different annotations of the code are required for each of the compilers, due to different interpretations of the fairly new standard by the compiler developers. Both versions of the OpenACC accelerated code achieved significant performance improvements, with up to 30 speedup against the sequential CPU code using recent hardware technology. Moreover, we demonstrated that the GPU-accelerated fully explicit MOT-TDVIE solver leveraged energy-consumption gains of the order of 3 against its CPU counterpart.
Scientific Computing - Linux in Scientific World

Jan 21, 2014 http://www.acadox.com/class/2485

This course is an introduction to Scientific Computing and Linux.

As Linux is the platform of choice for Scientific Computing, the course will introduce Linux from diverse aspects of Scientific Computing.

1-Science Day :

Alain Clo, Research Computing

David Keyes, Extreme Computing

Georgiy Stenchikov, Environmental Sciences

Antonio Attili, Clean Combustion Center

Ravi Samtaney, Mechanical Sciences

Luca Passone, Earth Sciences

Mousumi UpadhyayKahaly, Materials Sciences

Luigi Cavallo, Catalysis Center

2-HPC Day - Modelling Tools and High Performance Computing

Alain Clo, Research Computing

Imed Chihi, RED HAT

Santiago Ganis, ARAMCO

3-Visualization Day

Daniel Acevedo, Visualization Lab

Badr Harb, ARAMCO

4-Linux Desktop for Researchers

Edrisse Chermak, Catalysis Center

Waleed Harbi, Research Computing

Noor for Research

Jan 29, 2013 Noor for Research http://www.acadox.com/class/530

Noor for Research : Kaust Noor User Group
- What is Noor? Who is the team behind ? Alain
- The History and Future of Noor-Mohamed
- Who are the Users, Researchers and Faculty members and were their Achievements ?
-Toast
Details of the Outline :
KAUST IT Research Computing – 20 min
- Noor User Group Community
- Research Computing Team
- Noor
- Future (Expansion)
Faculty Achievements or Successes – 1 hour 30 min
- 9:50 10:10 Marie-Jean Thoraval : Von Karman Vortex Street within an Impacting Drop
- 10:10 10:30 Yan Azdoud : MultiScale Simulation of Non-Local Models
- 10:30 10:50 Roberto Incitti : High Throughput DNA Sequencing
- 10:50 11:10 Martin Mai : Earthquake Rupture Dynamics in Elastic & Plastic Media :
- 11:10 11:30 Mousumi UpadhyayKahaly : Electronic and Physical Properties of Nanostructures: NOOR for "on-computer" experiments
- 11:30 11:50 Antonio Attili : HPC for Reactive Flow and Turbulent Aerosol Simulations: a Perspective
User Group Feedback and Open Discussion
Hybrid Computing and Programming at KAUST

Jan 28, 2013 http://www.acadox.com/class/18635

This course will cover the following topics :
- Introduction the Opportunity for Kaust - Alain
- Hybrid Computing in the World, and at Kaust, the Ecosystem and the Market - Alain
- OpenACC, ManyCores - Florent
. Manycores, a technology disruption - Florent
. Hybrid Programming for Heterogeneous Platforms - Florent
- Economics -CapEX - OpEX - Florent
- Examples of Applications at KAUST:
a- Tutorial Easy to learn, implement and analyze - Saber
b- Seismic Imaging - Saber
c- ElectroMagnetic Waves Propagation - Alain
GP-GPU Acceleration of the Explicit Solution of the Time Domain Volume Integral Equation Using OpenACC

Nov 13, 2012 KAUST https://www.hpc.kaust.edu.sa/ikiwiki/sc12/presentations

A GP-GPU accelerated implementation of the explicit solution of the time domain volume integral equation (TD-VIE) using the OpenACC application program interface (API) is presented. The use of the OpenACC API allows for the ease of porting as well as the efficient computation of the TD-VIE solver onto GPUs with up to 50X speedups over a single core serial implementation on a CPU.
Multiphysics Simulations: Challenges and Opportunities

Oct 25, 2012 http://journals.sagepub.com/doi/pdf/10.1177/1094342012468181

Abstract
We consider multiphysics applications from algorithmic and architectural perspectives, where “algorithmic” includes both mathematical analysis and computational complexity and “architectural” includes both software and hardware environments. Many diverse multiphysics applications can be reduced, en route to their computational simulation, to a common algebraic coupling paradigm. Mathematical analysis of multiphysics coupling in this form is not always practical for realistic applications, but model problems representative of applications discussed herein can provide insight. A variety of software frameworks for multiphysics applications have been constructed and refined within disciplinary communities and executed on leading-edge computer systems. We examine several of these, expose some commonalities among them, and attempt to extrapolate best practices to future systems. From our study, we summarize challenges and forecast opportunities.
Keywords: multiphysics, multimodel, multirate, multiscale, implicit and explicit algorithms, strong and weak coupling, loose and tight coupling
Bonnes Pratiques et Catalogue de Solutions eGovernment, DG Information
Government Best Practices and Solution Catalog, DG Information Society, European Community Bruxelles 2005/2006 www.epractice.eu
Best Practices at Sun Microsystems, http://www.sun.com/government.xml
Internal to Sun : Many published papers to establish the Foundation of Public Sector Knowledge Management ( Market Trends and Sun Value Proposition in sub-markets such as Tax, Customs, Social Services, Healthcare, Criminal Justice, Postals, Local Government, Solutions such as Identity Management, Liberty Alliance, eGovernment Architecture, Mainframe Migration) in 2004/2005/2006

The KSR Programming Environment - A Case StudyThe KSR Programming Environment

Jan 1, 1993 Elsevier
S. Breit, A. Clo, H. Strauss, G. Vichniac
Parallel Computing: Trends and Applications, PARCO 1993, 1994
Describes one of the first environment using PThreads or Directives Driven in Fortran or C applications, on 64 bit OSF, in COMA (Cache Only Memory Architecture) Distributed Systems.
From compiling, analyzing compiler feedback and runtime, environment feedback from Presto (the KSR runtime environment based from PThreads).