RESUMEN
Purpose: To evaluate the visual acuity and quality of vision in bilaterally implanted ZCBOO/ZCTx monofocal (Johnson & Johnson Vision) intraocular lens (IOL) and bilaterally implanted DATx15 extended depth of focus (EDOF) IOL (Alcon Vision, LLC). Methods: A single site, non-interventional study comparing ZCBOO/ZCTx monofocal IOL patients implanted with DATx15 IOL toric or non-toric versions in both eyes. A total of 30 patients (60 eyes) completed the study in the monofocal group, 32 (64 eyes) in the EDOF group, and all were targeted for emmetropia. Binocular uncorrected distance, intermediate (66cm), and near (40cm) visual acuities and distance corrected distance, intermediate (66cm) and near (40cm) visual acuities were assessed. Binocular distance corrected defocus curve testing was from -3.5 D to +3 D. Patient reported visual disturbances (QUVID) and IOL satisfaction (IOLSAT) questionnaires were administered. Results: The DATx15 group mean uncorrected visual acuity was 0.15 ± 0.10 logMAR at 66cm and 0.36 ± 0.14 logMAR at 40cm, compared to 0.24 ± 0.15 logMAR and 0.59 ± 0.17 logMAR respectively for the ZCBOO/ZCTx group. The DATx15 group (23 respondents, 74%) also reported significantly more spectacle independence at near with the IOLSAT (p < 0.01), compared to the ZCBOO/ZCTx group (13 respondents, 43%). Glare, halos, starbursts, and blur reported on the QUVID questionnaire were similar in the two groups. Conclusion: The DATx15 group had improved near and intermediate vision and increased spectacle independence compared to the ZCBOO/ZCTx group.
RESUMEN
High performance miniaturized electronic devices require enhanced, compact and reliable thermal management system. As an efficient compact space cooling technique, flow boiling in microchannels has recently gained wide acceptance. However, weak buoyancy effects and microgravity in avionics and numerous space systems operations hinder the performance of flow boiling microchannel thermal management system due to poor bubble departure capacity and unfavorable development of flow regimes. Here we report the flow boiling silicon nanowires (SiNWs) microchannels which can favorably regulate two-phase flow regimes by enhancing explosive boiling, minimizing bubble departure diameter, and smoothing flow regime transition. Extensive experimental investigations along with high speed visualizations are performed. The experiments are performed with the dielectric fluid HFE-7100 in a forced convection loop for wide range of heat and mass fluxes. High speed flow visualizations have been employed at up to 70 k frames per second (fps) to understand the boiling mechanism in terms of bubble dynamics, flow patterns, and flow regime developments for SiNWs microchannels. These studies show that SiNWs reduce intermittent flow regimes (slug/churn), improve rewetting and maintain thin liquid film at wall. Therefore, flow boiling in SiNW microchannels is promising to thermal management owing to its high heat transfer rate with low pressure drop and negligible microgravity sensitivity.
RESUMEN
Development of smaller, faster, and more powerful electronic devices requires effective cooling strategies to efficiently remove ever-greater heat. Phase-change heat transfer such as boiling and evaporation has been widely exploited in various water-energy industries owing to its efficient heat transfer mode. Despite extensive progress, it remains challenging to achieve the physical limit of flow boiling due to highly transitional and chaotic nature of multiphase flows as well as unfavorable boundary layer structures. Herein, a new strategy that promises to approach the physical limit of flow boiling heat transfer is reported. The flow boiling device with multiple channels is characterized with the design of micropinfin fences, which fundamentally transforms the boundary layer structures and imparts significantly higher heat transfer coefficient even at high heat flux conditions, in which boiling heat transfer is usually deteriorated due to the development of dryout starting from outlet regions and severe two-phase flow instabilities. Moreover, the approaching of physical limit is achieved without elevating pressure drop.