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    Long-distance heat transfer between molecular systems through a hybrid plasmonic-photonic nanoresonator

    , Article Journal of Optics (United Kingdom) ; Volume 23, Issue 1 , 2021 ; 20408978 (ISSN) Ashrafi, M ; Malekfar, R ; Bahrampour, A. R ; Feist, J ; Sharif University of Technology
    IOP Publishing Ltd  2021
    Abstract
    We theoretically study a hybrid plasmonic-photonic cavity setup that can be used to induce and control long-distance heat transfer between molecular systems through optomechanical interactions. The structure we propose consists of two separated plasmonic nanoantennas coupled to a dielectric cavity. The hybrid modes of this resonator can combine the large optomechanical coupling of the sub-wavelength plasmonic modes with the large quality factor and delocalized character of the cavity mode that extends over a large distance (∼µm). We show that this can lead to effective long-range heat transport between molecular vibrations that can be actively controlled through an external driving laser. ©... 

    Correlation-enabled energy exchange in quantum systems without external driving

    , Article Physical Review A ; Volume 105, Issue 2 , 2022 ; 24699926 (ISSN) Pyhäranta, T ; Alipour, S ; Rezakhani, A. T ; Ala Nissila, T ; Sharif University of Technology
    American Physical Society  2022
    Abstract
    We study the role of correlation in mechanisms of energy exchange between an interacting bipartite quantum system and its environment by decomposing the energy of the system to local and correlation-related contributions. When the system Hamiltonian is time independent, no external work is performed. In this case, energy exchange between the system and its environment occurs only due to the change in the state of the system. We investigate the possibility of a special case where the energy exchange with the environment occurs exclusively due to changes in the correlation between the constituent parts of the bipartite system, while their local energies remain constant. We find sufficient... 

    Robust control of robotic manipulators based on -synthesis

    , Article 17th International Congress on Sound and Vibration 2010, ICSV 2010, Cairo, 18 July 2010 through 22 July 2010 ; Volume 1 , 2010 , Pages 525-532 ; 9781617822551 (ISBN) Moradi, H ; Bakhtiari Nejad, F ; Sadighi, M ; Ahmadian, M. T ; Sharif University of Technology
    2010
    Abstract
    A robotic manipulator is modelled as a cantilever rotating Euler-Bernoulli beam. Two dynamic transfer functions are derived to describe beam tip motion and angular rotation in terms of the desired angular rotation. Torque disturbance, imprecision in the payload mass, unknown properties of the manipulator link are sources of uncertainty. The objective is to achieve a desired angular rotation while the vibration of manipulator tip is suppressed. The control input of the system is an external driving torque. The -synthesis control approach is used and an H optimal robust controller is developed based on the DK-iteration algorithm. Results show that the designed controller guarantees the robust... 

    Active control of robotic manipulators vibration via feedback control

    , Article 17th International Congress on Sound and Vibration 2010, ICSV 2010, 18 July 2010 through 22 July 2010 ; Volume 1 , 2010 , Pages 464-471 ; 9781617822551 (ISBN) Moradi, H ; Bakhtiari Nejad, F ; Sadighi, M ; Alasty, A ; Sharif University of Technology
    Abstract
    In this paper, a robotic manipulator modelled as a cantilever rotating Euler-Bernoulli beam is considered. Control objective is achieving a desired angular rotation of the manipulator tip while its lateral vibration is suppressed. An external driving torque is the control input of the system. Two dynamic transfer functions are derived to describe beam tip motion and angular rotation in terms of the desired angular rotation. After state-space representation of the problem, an observer is designed to estimate state variables of the system. Then, a feedback control is designed for both regulation and tracking objectives. Eigenvalues are chosen such that an appropriate response is achieved while... 

    Optomechanical heat transfer between molecules in a nanoplasmonic cavity

    , Article Physical Review A ; Volume 100, Issue 1 , 2019 ; 24699926 (ISSN) Ashrafi, S. M ; Malekfar, R ; Bahrampour, A. R ; Feist, J ; Sharif University of Technology
    American Physical Society  2019
    Abstract
    We explore whether localized surface plasmon polariton modes can transfer heat between molecules placed in the hot spot of a nanoplasmonic cavity through optomechanical interaction with the molecular vibrations. We demonstrate that external driving of the plasmon resonance indeed induces an effective molecule-molecule interaction corresponding to a heat transfer mechanism that can even be more effective in cooling the hotter molecule than its heating due to the vibrational pumping by the plasmon. This mechanism allows us to actively control the rate of heat flow between molecules through the intensity and frequency of the driving laser. © 2019 American Physical Society  

    A new detection chamber design on centrifugal microfluidic platform to measure hemoglobin of whole blood

    , Article SLAS Technology ; Volume 26, Issue 4 , 2021 , Pages 392-398 ; 24726303 (ISSN) Mahmodi Arjmand, E ; Saadatmand, M ; Eghbal, M ; Bakhtiari, M. R ; Mehraji, S ; Sharif University of Technology
    SAGE Publications Inc  2021
    Abstract
    Undoubtedly, microfluidics has been a focal point of interdisciplinary science during the last two decades, resulting in many developments in this area. Centrifugal microfluidic platforms have good potential for use in point-of-care devices because they take advantage of some intrinsic forces, most notably centrifugal force, which obviates the need to any external driving forces. Herein, we introduce a newly designed detection chamber for use on microfluidic discs that can be employed as an absorbance readout step in cases where the final solution has a very low viscosity and surface tension. In such situations, our chamber easily eliminates the air bubbles from the final solution without...