Measured Transfer Efficiency Research Articles

Rotating convective turbulence in moderate to high Prandtl number fluids

Rotating convective turbulence is ubiquitously found across geophysical settings, such as surface and subsurface oceans, planetary atmospheres, molten metal planetary cores, magma chambers, magma oceans, and basal magma oceans. Depending on the thermal and material properties of the system, buoyant convection can be driven thermally or compositionally, where a Prandtl number ( Pr = ν / κ i ) defines the characteristic diffusion properties of the system, with κ i = κ T representing thermal diffusion and κ i = κ C representing chemical diffusion. These numbers vary widely for geophysical systems; for example, the liquid iron undergoing thermal-compositional convection in Earth's core is defined by P r T ≈ 0.1 and P r C ≈ 100 , while a thermally-driven liquid silicate magma ocean is defined by P r T ≈ 100 . Currently, most numerical and laboratory data for rotating convective turbulent flows exists at Pr = O ( 1 ) ; high Pr rotating convection relevant to compositionally-driven core flow and other systems is less commonly studied. Here, we address this deficit by carrying out a broad suite of rotating convection experiments made over a range of Pr values, employing water and three different silicone oils as our working fluids ( Pr = 6, 41, 206, and 993). Using measurements of flow velocities (Reynolds, Re) and heat transfer efficiency (Nusselt, Nu), a baroclinic torque balance is found to describe the turbulence regardless of Prandtl number so long as Re is sufficiently large ( Re ≳ 10 ). Estimated turbulent scales are found to remain close to onset scales in all experiments, a result that may extrapolate to planetary settings. Lastly, we use our data to build Pr-dependent predictive nondimensional and dimensional scaling relations for rotating convective velocities that can be applied across a broad range of geophysical fluid dynamical settings.

Förster resonance energy transfer efficiency measurements on vinculin tension sensors at focal adhesions using a simple and cost-effective setup.

Forces inside cells play a fundamental role in tissue growth, affecting important processes such as cancer cell migration or tissue repair after injury. Förster resonance energy transfer (FRET)-based tension sensors are a remarkable tool for studying these forces and should be made easier to use. We prove that absolute FRET efficiency can be measured on a simple setup, an order of magnitude more cost-effective than a standard FRET microscopy setup, by applying it to vinculin tension sensors (VinTS) at the focal adhesions of live CHO-K1 cells. Our setup located at Université Paris-Saclay acquires donor and acceptor fluorescence in parallel on two low-cost CMOS cameras and uses two LEDs for rapid switching of the excitation wavelength at a reduced cost. The calibration required to extract FRET efficiency was achieved using a single construct (TSMod). FRET efficiencies were measured for VinTS and the tail-less control VinTL, lacking the actin-binding domain of vinculin. Measurements were confirmed on the same cell type using a more standard intensity-based setup located at Rutgers University. The average FRET efficiency of VinTS () over more than 10,000 focal adhesions is significantly lower () than that of VinTL (), our control that is insensitive to force, in agreement with the force exerted on vinculin at focal adhesions. Attachment of the CHO-K1 cells on fibronectin decreases FRET efficiency, thus increasing the force, compared with poly-lysine. FRET efficiency for the VinTL control is consistent with all measurements currently available in the literature, confirming the validity of our measurements and hence of our simpler setup. Force measurements, resolved spatially inside a cell, can be achieved using FRET-based tension sensors with a cost effective intensity-based setup. This will facilitate combining FRET with techniques for applying controlled forces such as optical tweezers.

Equivalent Circuit Modeling and Experimental Analysis of Low Frequency Metamaterial for Efficient Wireless Power Transfer

This study proposes a low-frequency metamaterial(MM) coupled with an equivalent circuit model to emulate the behavior of an MM-based Wireless Power Transfer (WPT) system. For this purpose, the electromagnetic simulation and Finite Element Analysis (FEA) of the proposed MM-based WPT system are performed in ANSYS three-dimensional (3D) High-Frequency Structured Simulator (HFSS). In addition, numerical analysis of the circuit design of the proposed structure is performed in a MATLAB simulation environment to evaluate its transfer characteristics. While some methods, including effective medium theory and transmission line circuit model, have been exploited to explain the physical mechanism of MM-based WPT systems, some of the reactive parameters and the fundamental physical interpretation have not been clearly expounded. In contrast to existing theoretical models, the proposed approach focuses on the effect of system parameters of the MM and transfer coils on transfer characteristics, coupled with its effectiveness in analyzing complex circuits. A design prototype is fabricated for experimental measurement of power transfer efficiency and medium parameters using the KeySight ENA 5061 vector network analyzer (VNA), confirming the validity of the proposed design. The excellent efficiency enhancement and mutual coupling make the design an attractive solution for WPT applications. A close agreement of the experimental results and numerical simulation validates the accuracy of the analytical model.

Foraging behavior and pollination efficiency of generalist insects in an understory dioecious shrub Helwingia japonica

It has been hypothesized that pollination success in animal-pollinated dioecious plants relies on opportunistic pollinators with no discrimination against female flowers. However, empirical studies of pollinator foraging behavior and pollination effectiveness in dioecious species are few. To investigate potential pollinators in Helwingia japonica, a dioecious shrub with small, inconspicuous flowers, we compared floral visitors and visit frequency to female and male plants for three flowering seasons in two field populations in subtropical forests in southwest China. Pollen placement on the insect bodies of four groups (solitary bees and other bees, fungus gnats, and other flies) was compared, and insect foraging behavior was observed. Pollen removal and conspecific and heterospecific pollen deposition per visit were measured to compare pollination effectiveness among the four groups. Floral visitors usually did not discriminate between male and female flowers and did not gather pollen into collections. Our measurements of pollen transfer efficiency showed that solitary bees were the most effective pollinators with the highest conspecific pollen deposition. These insects seemed to be opportunistic visitors because pollen grains of H. japonica were distributed evenly over different regions of the visitor's body, and heterospecific pollen accounted for over 50% of total pollen loads on stigmas in the two populations. Our investigations indicated that potential pollinators were generalists and did not discriminate against female flowers, as predicted for dioecious species pollinated by insects. A perspective of pollen removal by floral visitors offers insights into the evolution of plant sexual systems.

Accuracy of 1H-1H distances measured using frequency selective recoupling and fast magic-angle spinning.

Selective recoupling of protons (SERP) is a method to selectively and quantitatively measure magnetic dipole-dipole interaction between protons and, in turn, the proton-proton distance in solid-state samples at fast magic-angle spinning. We present a bimodal operator-based Floquet approach to describe the numerically optimized SERP recoupling sequence. The description calculates the allowed terms in the first-order effective Hamiltonian, explains the origin of selectivity during recoupling, and shows how different terms are modulated as a function of the radio frequency amplitude and the phase of the sequence. Analytical and numerical simulations have been used to evaluate the effect of higher-order terms and offsets on the polarization transfer efficiency and quantitative distance measurement. The experimentally measured 1H-1H distances on a fully protonated thymol sample are ∼10%-15% shorter than those reported from diffraction studies. A semi-quantitative model combined with extensive numerical simulations is used to rationalize the effect of the third-spin and the role of different parameters in the experimentally observed shorter distances. Measurements at high magnetic fields improve the match between experimental and diffraction distances. The measurement of 1H-1H couplings at offsets different from the SERP-offset has also been explored. Experiments were also performed on a perdeuterated ubiquitin sample to demonstrate the feasibility of simultaneously measuring multiple quantitative distances and to evaluate the accuracy of the measured distance in the absence of multispin effects. The estimation of proton-proton distances provides a boost to structural characterization of small pharmaceuticals and biomolecules, given that the positions of protons are generally not well defined in x-ray structures.

Methodology for Energy Optimization in Wastewater Treatment Plants. Phase II: Reduction of Air Requirements and Redesign of the Biological Aeration Installation

Phase I of the proposed energy optimization methodology showed how the selection of best management criteria for the biological aeration process, and the guarantee of its control at the wastewater treatment plant (WWTP) in San Pedro del Pinatar (Murcia, Spain) produced reductions of around 20% in energy consumption by considerably reducing the oxygen needs of the microorganisms in the biological system. This manuscript focused on phase II of this methodology, which describes the tools that can be used to detect and correct deviations in the optimal operating points of the aeration equipment and the intrinsic deficiencies in the installation, in order to achieve optimization of the oxygen needs by the microorganisms and improve the efficiency of their transfer from the gas phase to the liquid phase. The objectives pursued were: (i) to minimize the need for aeration, (ii) to reduce the pressure losses in the installation, (iii) to optimize the air supply pressures to avoid excessive energy consumption for the same airflow, and (iv) to optimize the control strategy for the actual working conditions. The use of flow modeling and simulation techniques, the measurement and calculation of air transfer efficiency through the use of off-gas hoods, and the redesign of the aeration facility at the San Pedro del Pinatar WWTP were crucial, and allowed for reductions in energy consumption in Phase II of more than 20%.

Wide dipole antennas for wireless powering of miniaturised bioelectronic devices

Biomedical electronic implants require a power source to operate. Miniaturised implants can preclude batteries and as implant dimensions reduce further, inductive power transfer no longer becomes the optimum strategy for wireless power delivery. Wide dipole antennas are proposed as an alternative power transmitter for long and thin implants. A miniaturised bioelectronic device measuring 1 mm by 1 mm by 20 mm was fabricated, wirelessly powered and used to stimulate retinal ganglion cells to provide biological validation of its functionality. Optimised wide dipole antennas operating in the GHz range for implant depths of 5 mm to 35 mm in 5 mm steps were simulated, fabricated and measured. Saline solution was used as a biological tissue phantom for power transfer efficiency measurements. The maximum safe deliverable power to the device was 1.7 mW in simulation and 1.3 mW in measurement at power transfer efficiencies of 15% and 11% respectively. The work herein confirms that wide dipole transmitting antennas are suitable for radiative near field power transfer to long and thin implants. This power transfer technique could be used for implants that are injectable, deliverable via catheter and minimally invasive, advancing the aim to create smaller more innovative electronic implantable devices.

Systematically controlled fluorescence resonance energy transfer from cadmium telluride quantum dots to rhodamine 101 dye: steady-state versus time-resolved measurements

This article highlights the studies on precise measurements of energy transfer efficiency in a steady-state method by adopting sample preparation methods. Steady-state and time-resolved fluorescence measurements were employed to evaluate the cadmium telluride (CdTe) quantum dot (QD) photoluminescence quenching induced by the proximal rhodamine 101 dye (Rh 101) molecule via fluorescence resonance energy transfer (FRET). Further, the evaluation of steady-state measurements in comparison with time-resolved measurements was carried out. The FRET parameters, such as spectral overlap, Forster distance, and intermolecular distance for each donor–acceptor pair, were determined and variation of these parameters with respect to the size of the QD is discussed. Further, efforts to understand the optical and carrier relaxation dynamics of CdTe QDs are made using steady-state and time-resolved fluorescence data.

Toward fast, low-noise charge-coupled devices for Lynx

Lynx requires large-format x-ray imaging detectors with performance at least as good as the best current-generation devices but with much higher readout rates. We are investigating an advanced charge-coupled device (CCD) detector architecture under development at MIT Lincoln Laboratory for use in the Lynx high-definition x-ray imager and x-ray grating spectrometer instruments. This architecture features a CMOS-compatible detector integrated with parallel CMOS signal processing chains. Fast, low-noise amplifiers and highly parallel signal processing provide the high frame rates required. CMOS-compatibility of the CCD enables low-power charge transfer and signal processing. We report on the performance of CMOS-compatible test CCDs read at pixel rates up to 5.0 Mpix s − 1 (50 times faster than Chandra ACIS CCDs), with transfer clock swings as low as 1.0-V peak-to-peak (power/gate-area comparable to ACIS CCDs at 100 times the parallel transfer rate). We measure read noise of 4.6 electrons RMS at 2.5 MHz and x-ray spectral resolution better than 150-eV full-width at half maximum at 5.9 keV for single-pixel events. We report charge transfer efficiency measurements and demonstrate that buried channel trough implants as narrow as 0.8 μm are effective in improving charge transfer performance. We find that the charge transfer efficiency of these devices drops significantly as detector temperature is reduced from ∼ − 30 ° C to −60 ° C. We point out the potential of previously demonstrated curved-detector fabrication technology for simplifying the design of the Lynx high-definition imager. We discuss the expected detector radiation tolerance at these relatively high transfer rates. Finally, we note that the high pixel “aspect ratio” (depletion depth: pixel size ≈9 ∶ 1) of our test devices is similar to that expected for Lynx detectors and discuss implications of this geometry for x-ray performance and noise requirements.

Evaluation of FWD Load Transfer Efficiency Measurement

This report documents an evaluation of load transfer efficiency (LTE) of dowel jointed concrete pavements. Measurement of LTE of transverse joints in concrete pavements is universally conducted using a falling weight deflectometer (FWD) device. LTE is an important parameter affecting pavement performance. Due to the importance of the results for maintenance decisions, the accuracy of the measurement technique is investigated in this report. The availability of instrumented dowel fitted concrete slabs in West Virginia Smart Road (Corridor H, Route 33 as well as Goshen Road, West Virginia) offers a unique opportunity to examine the accuracy of determining the LTE of transverse joints using FWD. For this purpose, FWD tests were conducted on both pavement sites at different times during years 2003, 2004, and 2005. Thirty transverse joints were tested along the slab edges as well as along the wheel-path. Trend analysis was performed to evaluate the effect of design features and site conditions on LTE. Key findings from this study are: (1) LTE was found to be a complex parameter that depends on many factors that include load position, testing time, slab temperature, and load transfer device. (2) Testing time and season were found to have a significant effect on the measured LTE. (3) The slabs fitted with 32 mm (1.25 in.) diameter dowels displayed higher variability of the measured LTE than those fitted with 38 mm (1.5 in.) diameter dowels. (4) Joint opening changes daily and seasonally as the ambient temperature changes. As the amount of joint opening increases due to slab contraction during winter, the measured LTE generally decreases. (5) Poor correlation was found between the deflection-based LTE and the percentage of the load transferred through the load transferring devices mounted across the transverse joint.

Knowledge transfer efficiency measurement with application for open innovation networks

Knowledge transfer efficiency is an important indicator to evaluate the performance of open innovation (OI). However, there are few researches on the measurement of knowledge transfer efficiency in the context of OI networks. To make up this gap, this study explores the measurement of knowledge transfer efficiency based on the weighted OI network. Firstly, this paper builds the weighted OI network model with node and edge weights. On the basis of the weighted OI network model, the weighted path length and clustering coefficient are introduced and analysed. Moreover, the efficiency of knowledge transfer is further proposed as the main measure of knowledge transfer efficiency by comprehensively embodying the above factors, and then an extended application of the proposed main measure is developed to identify and locate the important members with great impact on knowledge transfer. Finally, a real case of several OI networks is provided to illustrate the applicability of the weighted OI network model and the knowledge transfer efficiency measurement method.

Printed Spiral Resonator for Displacement-Tolerant Near-Field Wireless Energy Transfer

Synthesis between the printed spiral coil and the planar interdigital capacitor for near-field wireless energy transfer (WET) is proposed. The proposed amalgamated design is intentionally positioned under several displacements, namely, planar offsets at the z-axis as well as lateral offsets at both the xand y-axes to investigate tolerance capability. This is particularly crucial in practical circumstances, whereby a perfect alignment between primary and secondary resonators is not usually achieved unless with the integration of magnet plates to aid seamless position latching, otherwise complex adaptive matching circuits are needed to compensate for displacements. At a fixed axial transfer distance of 25 mm, the corresponding maximum simulated and measured transfer efficiency is 73.01% and 71.84%, respectively, under perfect alignment. Sustainable power transfer efficiency (PTE) is demonstrated during a 360° planar clockwise rotation with the step size of 45° and the measured variation ratio is 0.02 while the feasibility of preserving PTE until 0.6 quotients of lateral displacement and axial distance is validated when up to 15-mm lateral offsets occur either from x or y reference planes. It can thus be concluded that the printed spiral resonator proposed appears to be a good candidate to rectify planar and lateral displacements featuring simplicity and space-saving robust structure that necessitates only a minimized footprint, thus paving the way for adaptation in WET applications, such as consumer electronics and implanted medical devices.

Role of IRF4 in the Protection of Metformin-Mediated Sepsis Myocarditis.

Aims:Metformin has been shown to play a protective role in diabetes. However, we found that metformin could mediate myocardial protection. Given that protein kinase C eplison (PKCε) and interferon regulatory factor 4 (IRF4) are critical for cardioprotection signaling. And measurement of fluorescence resonance energy transfer (FRET) efficiency can be used to determine whether 2 fluorophores are within a certain distance of each other. So we sought to determine whether metformin promotes PKCε/IRF4 activation by FRET.Methods and Results:The study built a mouse septic myocarditis model by intraperitoneal injection of Escherichia coli; thus, it provides valuable experimental data for the diagnosis and treatment of septic myocarditis. And cellular model of cardiomyocyte damage from adult rat cardiacmyocytes or H9c2 cells was induced by lipopolysaccharide employed to examine PKCε by molecular, biochemical, and cellular imaging analysis. Life span of septic myocarditis mouse was significantly prolonged by metformin. Metformin also decreased transforming growth factor β level and increased interleukin-10 productions. The FRET analysis in H9c2 cells suggested that there is prominent FRET signal for PKCε along in mitochondrial by metformin.Conclusion:We demonstrate that metformin promotes rapid association of PKCε with IRF4 at mitochondrial microdomain of cardiac myocytes and PKCε via direct molecular interaction with IRF4. This regulatory mechanism may play an important role in cardioprotection.

Evaluation of Dissolved Cesium Removal and Oxygen Tranfer Efficiency by Mode Change of Underwater Radial Impeller

The purpose of this study was to develop a process that can be applied to the diffusion of radioactive pollutants in the water due to radioactive fallout. We designed and fabricated an underwater radial impeller with various characteristics and measured the oxygen transfer efficiency and the mixing/diffusion efficiency of the adsorbent. The aim of this study was to develop a treatment technology that can be operated not only for emergency conditions due to diffusion of radioactive pollutants but also for normal water pollution. Experiments were carried out in a water tank for the measurement of oxygen transfer efficiency. The adsorbents used in the adsorption experiments were carried out using natural illite. We tried to derive normal and emergency operating conditions through the analysis of standard oxygen delivery and the results of the mixed diffusion efficiency of the impeller when the adsorbent is introduced. Key words: Water circulator, Adsorption, Impeller, Illite, Cesium

Microsecond resolved single-molecule FRET time series measurements based on the line confocal optical system combined with hybrid photodetectors.

Single-molecule (sm) fluorescence time series measurements based on the line confocal optical system are a powerful strategy for the investigation of the structure, dynamics, and heterogeneity of biological macromolecules. This method enables the detection of more than several thousands of fluorescence photons per millisecond from single fluorophores, implying that the potential time resolution for measurements of the fluorescence resonance energy transfer (FRET) efficiency is 10 μs. However, the necessity of using imaging photodetectors in the method limits the time resolution in the FRET efficiency measurements to approximately 100 μs. In this investigation, a new photodetector called a hybrid photodetector (HPD) was incorporated into the line confocal system to improve the time resolution without sacrificing the length of the time series detection. Among several settings examined, the system based on a slit width of 10 μm and a high-speed counting device made the best of the features of the line confocal optical system and the HPD. This method achieved a time resolution of 10 μs and an observation time of approximately 5 ms in the sm-FRET time series measurements. The developed device was used for the native state of the B domain of protein A.

Magnetic resonance wireless power transfer for laptop computer with a ground plane

ABSTRACTThis paper proposes a new method to increase the transfer efficiency of a wireless power transfer (WPT) system, having a source coil, a sprial transmitter (Tx) coil, a load coil and a ground plane, by utilizing the ground plane itself. The creation of cross slits at the ground center and employment of a lumped capacitor on the ground plane transform the ground plane into an additional resonator, which makes the original WPT system work as a 4‐coil WPT system, producing a higher efficiency. By experiment, with an optimized capacitor on the ground plane of C = 2180 pF, the measurement of transfer efficiency shows a maximum improvement of 10% at a transfer distance of 40 cm, compared to the case without the ground plane. The transfer efficiency of the proposed system at transfer distance of 15 cm is 46%. Circuit theory and electromagnetic simulations are employed to analyze the proposed WPT system, giving results consistent with the measured ones. The operating frequency of the proposed system is 6.78 MHz. © 2017 Wiley Periodicals, Inc. Microwave Opt Technol Lett 59:514–521, 2017

Precision measurement system and analysis of low core signal loss in DCF couplers

In order to achieve higher output power of double cladding fiber lasers, low signal loss has become a focus in researches on optical technology, especially double-clad fiber (DCF) couplers. According to the analysis, DCF couplers with low core signal loss (less than 1%) are produced. To obtain higher precision, we use the first-proposed method for core signal transfer efficiency measurement based on the fiber propagation field image processing. To the best of our knowledge, we report, for the first time, the results of the core signal loss less than 1% in DCF coupler measured by our measurement with high stability and relative precision. The measurement values can assess the quality of DCF couplers and be used as a signal to suggest the improvement on the processing technology of our self-made DCF couplers.

Measurement of scintillation and ionization yield with high-pressure gaseous mixtures of Xe and TMA for improved neutrinoless double beta decay and dark matter searches

The gaseous Xenon(Xe) time projection chamber (TPC) is an attractive detector technique for neutrinoless double beta decay and WIMP dark matter searches. While it is less dense compared to Liquid Xe detectors, it has intrinsic advantages in tracking capability and better energy resolution. The performance of gaseous Xe can be further improved by molecular additives such as trimethylamine(TMA), which is expected to (1) cool down the ionization electrons, (2) convert Xe excitation energy to TMA ionizations through Penning transfer, and (3) produce scintillation and electroluminescence light in a more easily detectable wavelength (300 nm). In order to test the feasibility of the performance improvements with TMA, we made the first direct measurement of Penning and fluorescence transfer efficiency with gaseous mixtures of Xe and TMA. While we observed a Penning transfer efficiency up to ∼35%, we found strong suppression of primary scintillation light with TMA. We also found that the primary scintillation light with Xe and TMA mixture can be well characterized by ∼3% fluorescence transfer from Xe to TMA, with further suppression due to TMA self-quenching. No evidence of the scintillation light produced by recombination of TMA ions was found. This strong suppression of scintillation light makes dark matter searches quite challenging, while the possibility of improved neutrinoless double beta decay searches remains open. This work has been carried out within the context of the NEXT collaboration.

Experimental estimation of migration and transfer of organic substances from consumer articles to cotton wipes: Evaluation of underlying mechanisms.

The aim of this work was to identify the key mechanisms governing transport of organic chemical substances from consumer articles to cotton wipes. The results were used to establish a mechanistic model to improve assessment of dermal contact exposure. Four types of PVC flooring, 10 types of textiles and one type of inkjet printed paper were used to establish the mechanisms and model. Kinetic extraction studies in methanol demonstrated existence of matrix diffusion and indicated the presence of a substance surface layer on some articles. Consequently, the proposed substance transfer model considers mechanical transport from a surface film and matrix diffusion in an article with a known initial total substance concentration. The estimated chemical substance transfer values to cotton wipes were comparable to the literature data (relative transfer ∼ 2%), whereas relative transfer efficiencies from spiked substrates were high (∼ 50%). For consumer articles, high correlation (r(2)=0.92) was observed between predicted and measured transfer efficiencies, but concentrations were overpredicted by a factor of 10. Adjusting the relative transfer from about 50% used in the model to about 2.5% removed overprediction. Further studies are required to confirm the model for generic use.

Quantitative Kα line spectroscopy for energytransport in fast ignition plasma driven with LFEX PW laser

Quantitative high-energy X-ray spectroscopy is applied for the laser plasma interaction in the fast ignition scheme. A double tracer layer target is designed for the absolute measurement of hot electron temperature and laser energy transfer efficiency. The hot electron temperature is determined from the ratio of the number of Kα photons from the first and second tracers. Consequently, the energy transfer efficiency from incident laser beams to hot electrons, as the energy transfer mechanism, is derived. In a cone-guide geometry, we simultaneously measured the hot electron temperature and the energy transfer efficiency from the incident LFEX, a kJ-class PW laser, which were measured to be 5.3 MeV and 37%, respectively.