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’

The talk with present the key results of the IPCC Working Group III 5th assessment report. Concluding four years of intense scientific collaboration by hundreds of authors from around the world, the report responds to the request of the world's governments for a comprehensive, objective and policy neutral assessment of the current scientific knowledge on mitigating climate change. The report has been extensively reviewed by experts and governments to ensure quality and comprehensiveness.

Climate change 2014 - Mitigation of climate change

Regardless of the specific photovoltaic (PV) technologies, PV can generate 89% of potential harmful air emission per kilowatt-hour, when compared to conventional fossil fuel. The production of PV cells involves chemical hazards related to the materials' toxicity, corrosivity, flammability, and explosiveness. This chapter discusses the materials processing in major technologies, such as silicon, thin film, and new generation solar cells, particularly about the toxicity of the materials to humans and biota.

Potential Environmental Impacts From Solar Energy Technologies

This paper compares the features and performance of two secondary optics when combined with an LED. The aim and application of the secondary optic are explained in the introduction section. Sections 2 and 3 introduce two optics: A freeform lens and a novel circular dielectric totally internally reflecting optic (CDTIRO), which can provide uniform illumination. The design process, ray tracing simulations and experimental performance of the freeform lens are described in detail in Section 2. The ray tracing simulation and experimental performance of the CDTIRO are presented in Section 3. Section 4 presents a comparison of the features of both lenses and their performance. Both optics can produce over 95% uniformity within an illuminated area. However, the uniformity produced by the freeform lens reduces abruptly compared with the CDTIRO when some parameters such as size and the position of the light source are changed.

Performance Comparison of a Freeform Lens and a CDTIRO When Combined With an LED

Solar energy is going to be a major component of global energy generation. Loss due to dust deposition has raised a great concern to the investors in this field. Pre-estimation of this reduced generation and hence the economic loss will help the operators’ readiness for efficient and enhanced economic energy management of the system. In an earlier article, a physics–based model is proposed for assessment of dust accumulation under various climatic conditions which is validated by data of a single location. In this paper, the universality of this model is established and is used to demonstrate the effect of generation loss due to dust deposition and of cleaning. Variation in the soiling pattern due to climatic covariates has also been studied. Generation loss is calculated for Solar Photovoltaic power plants of different capacities at various locations in India. Finally this model has also been extended to predict the generation accounting for the soiling loss in Photovoltaic system. All the calculated and predicted results are validated with the measured values of the above plants.

Model Based Generation Prediction of SPV Power Plant Due to Weather Stressed Soiling

The internal photoluminescence quantum yield of β-NaYF4:Er3+ is determined under broadband excitation and a photovoltaic-upconverter system with concentrating integrated optics is proposed to enhance the near-infrared response of silicon solar cells.

Enhancement of Upconversion for Photovoltaics with β-NaYF4:Er3+ and Concentrating Integrated Optics

Performance improvement of a desiccant based cooling system by mitigation of non-uniform illumination on the coupled low concentrating photovoltaic thermal units

Tapas K. Mallick

Papers

Potential Environmental Impacts From Solar Energy Technologies

Performance Comparison of a Freeform Lens and a CDTIRO When Combined With an LED

Model Based Generation Prediction of SPV Power Plant Due to Weather Stressed Soiling

Enhancement of Upconversion for Photovoltaics with β-NaYF4:Er3+ and Concentrating Integrated Optics

Performance improvement of a desiccant based cooling system by mitigation of non-uniform illumination on the coupled low concentrating photovoltaic thermal units