Early detection of living bacteria attracts a lot of attention in infection diseases applications, especially at low concentration. Nowadays, the detection of specific bacteria faces challenges including enhancement o...
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Early detection of living bacteria attracts a lot of attention in infection diseases applications, especially at low concentration. Nowadays, the detection of specific bacteria faces challenges including enhancement of trapping efficiency, and increase of sensor sensitivity and specificity. In this study, we improved the trapping efficiency and increased sensor sensitivity and specificity by using AC electrokinetics and selective modification of antibody on gold electrode in a new structure of gold electrode design. COMSOL simulations of AC electrokinetics include dielectrophoresis (DEP), and AC electroosmosis (ACEO) were performed on different electrode designs and bias configurations. The simulation results were consistent with the fluorescence observations showing that the bacteria were trapping selectively on gold electrodes. The impedance measurements for Vibrio parahaemolyticus (Vp) detection at 105 cfu/ml with AC elctrokinetics showed a nearly 90% change in normalized impedance change (NIC).
We report two-dimensional discrete dislocation dynamics simulations of combined dislocation glide and climb leading to “power-law” creep in a model aluminum crystal. The approach fully accounts for matter transport ...
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We report two-dimensional discrete dislocation dynamics simulations of combined dislocation glide and climb leading to “power-law” creep in a model aluminum crystal. The approach fully accounts for matter transport due to vacancy diffusion and its coupling with dislocation motion. The existence of quasiequilibrium or jammed states under the applied creep stresses enables observations of diffusion and climb over time scales relevant to power-law creep. The predictions for the creep rates and stress exponents fall within experimental ranges, indicating that the underlying physics is well captured.
Summary form only given. Continuous scaling of Si CMOS devices and circuits, increased speed and integration densities resulted in problems with thermal management of nanoscale device and computer chips. Further progr...
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Summary form only given. Continuous scaling of Si CMOS devices and circuits, increased speed and integration densities resulted in problems with thermal management of nanoscale device and computer chips. Further progress in information, communication and energy storage technologies requires more efficient heat removal methods and stimulates the search for thermal interface material (TIMs) with enhanced thermal conductivity. The commonly used TIMs are filled with the particles such as silver or silica. The conventional TIMs require high volume fractions of the filler (~70%) to achieve thermal conductivity of ~1-5 W/mK. Recently, some of us discovered that graphene has extremely high intrinsic thermal conductivity, which exceeds that of carbon nanotubes. To use this property for thermal management of nanoscale electronic devices, we utilized the inexpensive liquid-phase exfoliated graphene and multi-layer graphene (MLG) as filler materials in TIMs. The thermal properties of the obtained graphene-epoxy composites were measured using the “laser flash” technique. It was found that the thermal conductivity enhancement factor exceeded a factor of 23 at 10% of the graphene volume loading fraction. This enhancement is larger than anything that has been achieved using other fillers. We have also tested graphene flakes in the electrically-conductive hybrid graphene-metal particle TIMs. The thermal conductivity of resulting composites was increased by a factor of ~5 in a temperature range from 300 K to 400 K at a small graphene loading fraction of 5-vol.-%. The unusually strong enhancement of thermal properties was attributed to the high thermal conductivity of graphene, strong graphene coupling to matrix materials and the large range of the length-scale - from nanometers to micrometers - of the graphene and silver particle fillers. Graphene-based TIMs have a number of other advantages related to their viscosity and adhesion, which meet the industry requirements. Our results su
In this paper, a multi-functional of multi-layer planar micro-coils chip is demonstrated to play as actuators and heaters. For playing as actuators, the micro-coil generate local magnetic field with applied current of...
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In this paper, a multi-functional of multi-layer planar micro-coils chip is demonstrated to play as actuators and heaters. For playing as actuators, the micro-coil generate local magnetic field with applied current of 15 mA to quickly manipulated magnetic beads to center of micro-coil within one minute. For functioning as heaters, the micro-coil heater can be quickly heated up to denatured temperature of 95 °C with input power of 50.5 mW, and its heating and cooling rate are 19.7 and 11.8 °C/s, respectively. For the typical 25 polymerase chain reaction (PCR) cycles, it took only 770 seconds. To further shrink and optimize the multi-layer planar micro-coils chip can be possibly used to manipulate single cell with magnetic beads to specific region and analyze its gene sequence by using single cell PCR technique.
Central to most applications involving graphenes flakes is its mechanical response under various stress/ strain states. In this work, we present an experimental study on single, bi- and tri-layer graphene flakes under...
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ISBN:
(纸本)9788888785332
Central to most applications involving graphenes flakes is its mechanical response under various stress/ strain states. In this work, we present an experimental study on single, bi- and tri-layer graphene flakes under uniaxial tensile strain, for low levels of strain. Graphene layers were subjected to tensile loading by employing a polymeric cantilever beam assembly, where the graphene flakes are embedded into the polymer beam. The mechanical response of graphenes is monitored by simultaneous Raman measurements through the shift of the G and 2D optical phonons, and their strain sensitivities are determined. The results can be used to quantify the amount of uniaxial strain, providing a fundamental tool for graphene based nanocomposites.
The agro and industrial activities are currently responsible for the production of large amounts of solid wastes. The use of industrial wastes such as granite, marble, kaolin and pegmatite and agro-industrial rejects ...
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The agro and industrial activities are currently responsible for the production of large amounts of solid wastes. The use of industrial wastes such as granite, marble, kaolin and pegmatite and agro-industrial rejects into clay products has been widely developed over the last few decades. Clay materials used in the ceramic industry exhibit a large diversification of compositions that al-low the addition of different types of waste materials to the clay mixture. Sugar cane bagasse ash (SCBA), a by-product of the sugar process, is exacerbating the environmental problem. Bra-zil produces an enormous amount of sugar and the lack of adequate landfill areas available for disposal of sugar cane bagasse ash rejects poses a critical problem for the agro-industry. This work describes, for the first time, research carried out on the manufacturing of ceramic tile mate-rials with sugar cane bagasse ash additions. SCBA, consisting basically of potassium oxide, was added to the clay formulations as an alternative to feldspar. Clay with different sugar cane ba-gasse ash content was mixed and sintered. Sintered specimens were characterized by X-ray dif-fraction, density, porosity, thermal analysis and strength measurements. The results obtained showed that the sugar cane ash residue can be added to clay materials as an alternative to feld-spar, without degrading their properties.
In this paper the amount and morphology of cortical and trabecular bone porosities were estimated using optical microscopy and micro-computed tomography technique. The hierarchical structure of porosity at different s...
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In this paper the amount and morphology of cortical and trabecular bone porosities were estimated using optical microscopy and micro-computed tomography technique. The hierarchical structure of porosity at different structural scales spanning from a single lacuna (sub-microscale) to trabecular or cortical bone levels (mesoscale) was characterized and described. This study was conducted by using samples of untreated, deproteinized and demineralized bones, to obtain better insight into the bone structure and porosities. The motivation of this work is that the porosity in bone has a major effect on its mechanical response, yet it is often neglected in bone models. Investigations of the mechanical properties of bone and its main components (collagen and mineral phases), complemented by modeling, are of importance in orthopedics.
We studied cycle time （0.01-10 s with triangular input waves） and poling history （continuous versus fresh poling） dependent electric energy storage and discharge behaviors in poly（vinylidene fluoride-co-hexafluor...
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We studied cycle time （0.01-10 s with triangular input waves） and poling history （continuous versus fresh poling） dependent electric energy storage and discharge behaviors in poly（vinylidene fluoride-co-hexafluoropropylene） [P（VDF- HFP）] films using the electric displacement -- the electric field （D-E） hysteresis loop measurements. Since the permanent dipoles in PVDF are orientational in nature, it is generally considered that both charging and discharging processes should be time and poling history dependent. Intriguingly, our experimental results showed that the charging process depended heavily on the cycle time and the prior poling history, and thus the D-E hysteresis loops had different shapes accordingly. However, the discharged energy density did not change no matter how the D-E loop shape varied due to different measurements. This experimental result could be explained in terms of reversible and irreversible polarizations. The reversible polarization could be charged and discharged fairly quickly （〈 5 ms for each process）, while the irreversible polarization depended heavily on the poling time and the prior poling history. This study suggests that it is only meaningful to compare the discharged energy density for PVDF and its copolymer films when different cycle times and poling histories are used.
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