Strain-engineered artificial atom as a broad-spectrum solar energy funnel

Photosynthesis provides an example of a natural process that has been optimized during evolution to harness solar energy efficiently and safely, and finally to use it to produce a carbon-based fuel. Initially, solar energy is captured by the light harvesting pigment-protein complexes. In purple bacteria these antenna complexes are constructed on a rather simple modular basis. Light absorbed by these antenna complexes is funnelled downhill to reaction centres, where light drives a trans-membrane redox reaction. The light harvesting proteins not only provide the scaffolding that correctly positions the bacteriochlorophyll a and carotenoid pigments for optimal energy transfer but also creates an environment that can modulate the wavelength at which different bacteriochlorophyll molecules absorb light thereby creating the energy funnel. How these proteins can modulate the absorption spectra of the bacteriochlorophylls will be discussed in this review.

Download Full-text

Rendez vous with Saturn's rings

International Astronomical Union Colloquium ◽

10.1017/s0252921100101885 ◽

1984 ◽

Vol 75 ◽

pp. 743-759 ◽

Cited By ~ 2

Author(s):

Kerry T. Nock

Keyword(s):

Solar Energy ◽

Electric Propulsion ◽

Power Source ◽

Propulsion System ◽

Low Thrust ◽

Ring Plane ◽

The Earth ◽

Total Impulse ◽

Saturn's Rings

ABSTRACTA mission to rendezvous with the rings of Saturn is studied with regard to science rationale and instrumentation and engineering feasibility and design. Future detailedin situexploration of the rings of Saturn will require spacecraft systems with enormous propulsive capability. NASA is currently studying the critical technologies for just such a system, called Nuclear Electric Propulsion (NEP). Electric propulsion is the only technology which can effectively provide the required total impulse for this demanding mission. Furthermore, the power source must be nuclear because the solar energy reaching Saturn is only 1% of that at the Earth. An important aspect of this mission is the ability of the low thrust propulsion system to continuously boost the spacecraft above the ring plane as it spirals in toward Saturn, thus enabling scientific measurements of ring particles from only a few kilometers.

Download Full-text

A Strengths-Based Approach to Autism: Neurodiversity and Partnering With the Autism Community

Perspectives of the ASHA Special Interest Groups ◽

10.1044/persp2.sig1.56 ◽

2017 ◽

Vol 2 (1) ◽

pp. 56-68 ◽

Cited By ~ 8

Author(s):

Amy L. Donaldson ◽

Karen Krejcha ◽

Andy McMillin

Keyword(s):

Broad Spectrum ◽

First Language ◽

Family Members ◽

Community Identity ◽

Speech Language Pathologists

The autism community represents a broad spectrum of individuals, including those experiencing autism, their parents and/or caregivers, friends and family members, professionals serving these individuals, and other allies and advocates. Beliefs, experiences, and values across the community can be quite varied. As such, it is important for the professionals serving the autism community to be well-informed about current discussions occurring within the community related to neurodiversity, a strengths-based approach to partnering with autism community, identity-first language, and concepts such as presumed competence. Given the frequency with which speech-language pathologists (SLPs) serve the autism community, the aim of this article is to introduce and briefly discuss these topics.

Download Full-text