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• An optical fiber daylighting system (OFDS) is implemented for an indoor farm, which allows addressing costly issues and achieving high efficiency. • An optimal design of the OFDS along with the various distances between the focal area and the optical fiber. • A concentration ratio of 140, optical efficiency of ∼19 % in simulation and ∼16 % in practice is demonstrated. • Energy saving can reach 54.3% on a sunny day and 38.9% on a cloudy day in an outdoor test. • Using the proposed OFDS helps the plant to grow better compared to using only LED. Optical fiber daylighting technology offers an effective path to deliver sunlight to an indoor farm that requires high energy consumption for illumination and a total visible spectrum for plant growth. However, the high cost of this technology can be seen as a drawback. In this study, the optimized daylighting system based on plastic optical fiber for indoor farm application is devised toward large-scale illumination with high efficiency and low cost. The proposed system comprises of a Fresnel lens array as a sunlight concentrator and plastic optical fiber bundles as a light transportation medium. Rather than previously common designs, we investigated the concentration properties of a non-imaging optics device – the Fresnel lens to find the optimal configuration of the system. Optimizing concentration ratio, optical efficiency, and overheating of an optical fiber daylighting system (OFDS) for the indoor farm application is carried out by simulation (LightTools software) and verified by experiments. The system design allows replacing the costly and sophisticated heat dissipation in conventional OFDS with only a UV-IR filter. The OFDS prototype is fabricated and tested in outdoor conditions. Results show that the proposed system archive concentration ratio of 140, the optical efficiency of ∼19 % by simulation, and ∼16 % by practice. Daylighting performance investigation on the installation of the prototype in the indoor farm demonstrates that energy saving can reach 54.3 % on a sunny day and 38.9 % on a cloudy day. Using proposed OFDS helps the plant to grow better than using LED only. Reliability tests and cost analyses show that our results provide an essential breakthrough for the application and commercialization of large-scale optical fiber daylighting technology for indoor agriculture. [ABSTRACT FROM AUTHOR]

• A fully new scheme of the daylighting using optical-fiber-less design and hybrid system. • Aiming to guide light deeply and efficiently for a given multi-storey building. • The optical efficiency and energy saving can reach 63.7 % and 46.5%, respectively. In this study, the fully new scheme of the daylighting system is devised and a few avenues are proposed toward large scale illumination area with the highly efficient luminous flux and modest cost. Rather than a previously common design, consisting of a sole system, we work out two subsystems for a generic daylighting system: outdoor and indoor subsystems. For the outdoor subsystem, aiming to guide light deeply and efficiently for a given multi-storey building, we first capitalize on a simple design of two mirrors to collect the sunlight and transport it in free-space, which negligibly penalizes the optical loss. To guide light to each particular area inside building, we further propose two options for the indoor subsystem taking into consideration between cost and performance: first with the Fresnel lens + circular plastic optical fiber (POF) bundle and second with the waveguide concentrator + flat POF bundle. The quantitative assessment unravels that the optical efficiency of the latter is higher than that of the former, 63.7 % vs 48.7 %. Still, the real implementation of the Fresnel lens + circular POF is more prone and we indeed demonstrate a principle-of-concept system. Such design also preferably implements with a LED panel, in an embodiment of a so-called hybrid daylighting system, to grant light in overcast and night-time situations. This proposed daylighting system also enables exceptional merit in calculated energy saving, up to roughly 46.5% in a year with sunlight condition as in Ho Chi Minh City (Vietnam), as electrical light is used properly and barely. All things taken into account, this approach indicates a likely perspective for fostering a new generation of the daylighting system that making use of sparingly optical fiber. [ABSTRACT FROM AUTHOR]

• A homogeniser inspired by the crustacean's eye using for the CPV system. • Such homogeniser can evolve a uniform version of light distribution. • The best structure displays a uniformity ~85% and an optical efficiency ~90%. • Toward relaxing a secondary mirror in the existing CPV system using a parabolic mirror. We devise an implicitly new design for boosting the light uniformity in the concentrated photovoltaics (CPV) system, whereby addressing the overheating issue of the PV cell and enhancing the electrical cell efficiency. Rather than using a well-known system of the Cassegrain concentrator design, consisting of double mirrors + a homogeniser, in this study, we mimic a structure of crustacean's eyes for a design of homogeniser, consisting of an array of a mirror channel. Such proposed design allows making use of only a primary parabolic mirror + a homogeniser to concentrate and redistribute the sunlight, representing a large departure from virtually all of the previous studies. Specifically, such homogeniser can furcate the light beam into the small channels/trenches, redirect the light ray at the reflective plate and probably mix them to evolve a uniform version of light distribution. In general, the homogeniser can affect the uniformity and optical efficiency, which are good probes to assess the light performance, in a number of ways. We found that light performance depends sizably on the structural parameters such as the size and the number of channels of the homogeniser. The best structure displays a calculated uniformity of ~85% of the flux distribution on solar cell and a calculated optical efficiency of ~90% of the entire CPV system. We also assess the light performance against some scenarios of error in installation and operation processes such as tolerance and misalignment and compare well with the current design. The compelling of this proposed design is highly efficient light performance, compactness and inexpensive, which likely address virtually existing bottlenecks in the CPV system. [ABSTRACT FROM AUTHOR]

The major challenge in photothermal therapy (PTT) is to develop nanocomposites that simultaneously exhibit bioimaging and PTT under a single near-infrared (NIR) irradiation with high therapeutic efficiency. Herein, we present a multifunctional nanocomposite synthesized by linking NaYF4:Yb3+,Er3+ upconversion nanoparticles (UCNPs) with gold nanorods (AuNR) to exhibit fluorescence labeling, local temperature sensing and photothermal functions simultaneously with a single NIR laser excitation. The AuNR-NaYF4:Yb3+,Er3+ nanocomposite particles displayed better photothermal properties compared with pure AuNRs or a blend of AuNRs and NaYF4:Yb3+,Er3+ UCNPs. The temperature-dependent upconversion luminescence (UCL) property was used to determine local temperature at the nanocomposite particles, which is useful for selecting appropriate irradiation dosage for PTT. The therapeutic performance of the nanocomposites in PTT for OML-1 oral cancer cells was determined. For cell labeling, we successfully labeled streptavidin-linked nanocomposite particles on the surface of OML-1 oral cancer using anti-human epidermal growth factor receptor 2 (anti-Her2) antibody. Finally, the nanocomposite particles caused exceptional destruction of cancer cells up to 70% dead cells under 976 nm laser irradiation for only one min at 0.3 W/cm2 which is below the maximal permissible exposure of human skin. [ABSTRACT FROM AUTHOR]