2,754 research outputs found
Artificial Photosynthesis Would Unify the Electricity-Carbohydrate-Hydrogen Cycle for Sustainability
Sustainable development requires balanced integration of four basic human needs – air (O2/CO2), water, food, and energy. To solve key challenges, such as CO2 fixation, electricity storage, food production, transportation fuel production, water conservation or maintaining an ecosystem for space travel, we wish to suggest the electricity-carbohydrate-hydrogen (ECHo) cycle, where electricity is a universal energy carrier, hydrogen is a clean electricity carrier, and carbohydrate is a high-energy density hydrogen (14.8 H2 mass% or 11-14 MJ electricity output/kg)carrier plus a food and feed source. Each element of this cycle can be converted to the other reversibly & efficiently depending on resource availability, needs, and costs. In order to implement such cycle, here we propose to fix carbon dioxide by electricity or hydrogen to carbohydrate (starch) plus ethanol by cell-free synthetic biology approaches. According to knowledge in the literature, the proposed artificial photosynthesis must be operative. Therefore, collaborations are urgently needed to solve several technological bottlenecks before large-scale implementation
Odd elasticity in Hamiltonian formalism
A host of elastic systems consisting of active components exhibit
path-dependent elastic behaviors not found in classical elasticity, which is
known as odd elasticity. Odd elasticity is characterized by antisymmetric (odd)
elastic modulus tensor. Here, from the perspective of geometry, we construct
the Hamiltonian formalism to show the origin of the antisymmetry of the elastic
moduli. Furthermore, both non-conservative stress and the associated nonlinear
constitutive relation naturally arise. This work also opens the promising
possibility of exploring the physics of odd elasticity in dynamical regime by
Hamiltonian formalism.Comment: 9 pages, 2 figure
Multi-Robot Object Transport Motion Planning with a Deformable Sheet
Using a deformable sheet to handle objects is convenient and found in many
practical applications. For object manipulation through a deformable sheet that
is held by multiple mobile robots, it is a challenging task to model the
object-sheet interactions. We present a computational model and algorithm to
capture the object position on the deformable sheet with changing robotic team
formations. A virtual variable cables model (VVCM) is proposed to simplify the
modeling of the robot-sheet-object system. With the VVCM, we further present a
motion planner for the robotic team to transport the object in a
three-dimensional (3D) cluttered environment. Simulation and experimental
results with different robot team sizes show the effectiveness and versatility
of the proposed VVCM. We also compare and demonstrate the planning results to
avoid the obstacle in 3D space with the other benchmark planner.Comment: 8 pages, 10 figures, accepted by RAL&CASE 2022 in June 24, 202
Quantum Cloning Machines and the Applications
No-cloning theorem is fundamental for quantum mechanics and for quantum
information science that states an unknown quantum state cannot be cloned
perfectly. However, we can try to clone a quantum state approximately with the
optimal fidelity, or instead, we can try to clone it perfectly with the largest
probability. Thus various quantum cloning machines have been designed for
different quantum information protocols. Specifically, quantum cloning machines
can be designed to analyze the security of quantum key distribution protocols
such as BB84 protocol, six-state protocol, B92 protocol and their
generalizations. Some well-known quantum cloning machines include universal
quantum cloning machine, phase-covariant cloning machine, the asymmetric
quantum cloning machine and the probabilistic quantum cloning machine etc. In
the past years, much progress has been made in studying quantum cloning
machines and their applications and implementations, both theoretically and
experimentally. In this review, we will give a complete description of those
important developments about quantum cloning and some related topics. On the
other hand, this review is self-consistent, and in particular, we try to
present some detailed formulations so that further study can be taken based on
those results.Comment: 98 pages, 12 figures, 400+ references. Physics Reports (published
online
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