Learn more about UC TechAlerts – Subscribe to categories and get notified of new UC technologies

Browse Category: Engineering > Engineering

Categories

[Search within category]

Type III CRISPR-Cas System for Robust RNA Knockdown and Imaging in Eukaryotes

Type III CRISPR-Cas systems recognize and degrade RNA molecules using an RNA-guided mechanism that occurs widely in microbes for adaptive immunity against viruses. The inventors have demonstrated that this multi-protein system can be leveraged for programmable RNA knockdown of both nuclear and cytoplasmic transcripts in mammalian cells. Using single-vector delivery of the S. thermophilus Csm complex, RNA knockdown was achieved with high efficiency (90-99%) and minimal off-targets, outperforming existing technologies of shRNA- and Cas13-mediated knockdown. Furthermore, unlike Cas13, Csm is devoid of trans-cleavage activity and thus does not induce non-specific transcriptome-wide degradation and cytotoxicity. Catalytically inactivated Csm can also be used for programmable RNA-binding, which the inventors exploit for live-cell RNA imaging. This work demonstrates the feasibility and efficacy of multi-subunit CRISPR-Cas effector complexes as RNA-targeting tools in eukaryotes.

Passive Elastomeric Valves for Microengines that Allow, Block, And Limit Fluid Flow In One Or More Directions

Millimeter scale internal combustion engines can conceivably be used to replace a battery in effectively any small portable powered system. Liquid hydrocarbon fuels hold 300 times the energy per weight unit than a NiCad battery and 100x that of a Li-ion battery. Such systems would not require charging, but changing of a fuel capsule that can occur instantaneously. Many polymer combustion micro-engines (e.g. ~1-gram combustion engines) rely on external systems to control valve function. Such systems include human control or active valves that open or close at predetermined times. These auxiliary systems can be far larger and heavier than the micro-engine itself, which limits the broader utility of the micro-engine. Current passive microfluidic valves are check valves - they allow flow in one direction, but block flow in the other and are impractical for most applications. 

Dual Capacitor Resonant Circuit

In existing converters, either a shunt-resonant capacitor or a series resonant capacitor is used.  Using only shunt-resonant capacitors results in the following challenges:A dedicated charging interval is required in every switching half-cycle, which does not contribute towards energy transfer and results in duty-cycle loss;A shunt-resonant capacitor is designed only to hold resonant energy sufficient for its rated current condition. Therefore, the resonant energy is fixed for all loading conditions;At reduced loading, a reduced resonant energy is sufficient but the shunt-configuration has no way to control  resonant energy. A converter with two additional MOSFETs can help, but this arrangement leads to increased losses and is also more expensive;At reduced loading, the duty-cycle loss increases significantly because the reduced current results in longer capacitor charging time. This severely restricts the operation range of the converter;Smooth current commutation and ZCS are lost at overload conditions since the capacitor is designed for its rated-current condition;The shunt-resonant capacitor is expected to hold its voltage/energy during the operating mode while the input inductor charges. However, a leakage path exists through the transformer winding parasitics, which can result in capacitor discharge.The capacitor energy must be overrated to compensate this loss, which further aggravates all the aforementioned issues.Using only series-resonant capacitor results in the following challenges:Precise control of resonant energy can only be achieved only by using additional switches, such as two additional reverse-blocking (RB) switches. However, this arrangement leads to increased losses and is also more expensive;To satisfy the resonant condition, the series-resonant capacitor must be charged to a voltage higher than the reflected voltage across the transformer-primary;The peak voltage-rating of primary-side components (e.g. the switches and input inductor) is increased;Series-capacitors also transfer energy to the output during the time interval when the resonant current commutation occurs. Therefore, the capacitor rating must be higherAt reduced loading, the capacitor will not have enough voltage across it to satisfy the resonant condition.One potential option uses switching frequency as an additional control parameter without using extra switches. However, a reduction in switching frequency results in increased charging time and hence, higher voltage. However, ripple content increases and requires a larger filter due to varying switching frequency.This invention achieves a balance between the benefits and drawbacks of series and shunt-resonant capacitor configurations. 

Slow Ion/Salt-Releasing Biodegradable Hydrogel for Aqueous Applications

This invention is a biodegradable hydrogel mixed with minerals/chemical substances to slowly release ions/salts into the nearby aqueous waterbody through gradual abrasion of surface gel layers performed by underwater current.

Power Transistor Light Emission For Gate Control And Reliability Monitoring

Methods for monitoring device operating conditions and current are shifting towards the use of optical measurements, which are are less susceptible to electromagnetic noise. Existing light emission techniques utilize complex components, like laser diodes and photodiodes, to measure device current, rendering such techniques expensive to implement.

Photo Rechargeable Li-Ion Battery

Brief description not available

Carbon Nanotube Infrared Detector

Brief description not available

Anticipatory Lane Change Warning Using Dsrc

Brief description not available

Systems and Methods for Scaling Electromagnetic Apertures, Single Mode Lasers, and Open Wave Systems

The inventors have developed a scalable laser aperture that emits light perpendicular to the surface. The aperture can, in principal, scale to arbitrarily large sizes, offering a universal architecture for systems in need of small, intermediate, or high power. The technology is based on photonic crystal apertures, nanostructured apertures that exhibit a quasi-linear dispersion at the center of the Brillouin zone together with a mode-dependent loss controlled by the cavity boundaries, modes, and crystal truncation. Open Dirac cavities protect the fundamental mode and couple higher order modes to lossy bands of the photonic structure. The technology was developed with an open-Dirac electromagnetic aperture, known as a Berkeley Surface Emitting Laser (BKSEL).  The inventors demonstrate a subtle cavity-mode-dependent scaling of losses. For cavities with a quadratic dispersion, detuned from the Dirac singularity, the complex frequencies converge towards each other based on cavity size. While the convergence of the real parts of cavity modes towards each other is delayed, going quickly to zero, the normalized complex free-spectral range converge towards a constant solely governed by the loss rate of Bloch bands. The inventors show that this unique scaling of the complex frequency of cavity modes in open-Dirac electromagnetic apertures guarantees single-mode operation of large cavities. The technology demonstrates scaled up single-mode lasing, and confirmed from far-field measurements. By eliminating limits on electromagnetic aperture size, the technology will enable groundbreaking applications for devices of all sizes, operating at any power level. BACKGROUND Single aperture cavities are bounded by higher order transverse modes, fundamentally limiting the power emitted by single-mode lasers, as well as the brightness of quantum light sources. Electromagnetic apertures support cavity modes that rapidly become arbitrarily close with the size of the aperture. The free-spectral range of existing electromagnetic apertures goes to zero when the size of the aperture increases. As a result, scale-invariant apertures or lasers has remained elusive until now.  Surface-emitting lasers have advantages in scalability over commercially widespread vertical-cavity surface-emitting lasers (VCSELs). When a photonic crystal is truncated to a finite cavity, the continuous bands break up into discrete cavity modes. These higher order modes compete with the fundamental lasing mode and the device becomes more susceptible to multimode lasing response as the cavity size increases. 

Modular Piezoelectric Sensor Array with Beamforming Channels for Ultrasound Imaging

Researchers at the University of California, Davis have developed a large area sensor array for ultrasound imaging systems that utilizes high-bandwidth piezoelectric sensors and modular design elements.

Multimodal Coatings For Heat And Fire Resistance

Brief description not available

(SD2020-249) Adaptive Bias Circuits For CMOS Millimeter-Wave Power Amplifiers: state-of-the-art back-off efficiency for silicon Ka-band Doherty PAs using single inputs and without digital predistortion

Power amplifier performance for emerging 5G mm-wave systems poses significant challenges for output power, efficiency and linearity. Efficiency in backoff is a key concern, given the peak-to-average power ratio of order 6-9dB for 5G signals. As a result, considerable attention has been given to composite amplifiers featuring backoff efficiency enhancement, particularly Doherty amplifiers. Adaptive bias circuits have been previously developed for use with power amplifiers at low microwave frequencies (for example, 1-2GHz as applied in 2G, 3G and 4G cellular networks).  Direct application of these techniques is not straightforward at higher frequencies, such as 28GHz as used for 5G wireless communications, because the transistors have less gain at the high frequencies. 

Workflow to Computationally Optimize Upcycling of Critical Metals from Spent Lit

This technology computationally optimizes the upcycling of critical metals in deep eutectic solvents with molecular dynamics, artificial intelligence, and experimental approaches.

Microchannel Polymer Heat Exchanger

Researchers at the University of California, Davis have developed a highly efficient microchannel polymer heat exchanger in a compact and lightweight design.

Modified Bauxite for Phosphate Recovery and Recycling

This technology shows three different forms of bauxite to be effective adsorbents for phosphate ions. 1. Mildly processed bauxite (MPB), which is essentially ball-milled raw bauxite ore, 2. Thermally activated bauxite (TAB), which is ball-milled bauxite ore subjected to 300 C roasting, and 3. Acid treated thermally activated bauxite (ATAB), which is ball-milled bauxite ore subjected to 300 C roasting and subsequent acid treatment using 5M HCl.  These three different forms of bauxite are shown to adsorb phosphate in high amounts from solutions containing a range of initial phosphate concentrations, 5 ppm to 631 ppm.  ATAB shows the highest adsorption density, demonstrating a value of 50 mg of PO4-/g ATAB at pH=6TAB shows an adsorption density of 25 mg PO4-/g TAB at pH=6  There are two industry standard materials for phosphate adsorption, activated magnesia (MgO), and activated alumina (Al2O3). For comparison, activated magnesia (MgO) demonstrates an adsorption capacity of 25 mg PO4-/g at pH=6. Activated alumina (Al2O3) shows an adsorption capacity of 11 mg PO4-/g at pH=6 (reference: Journal of Environmental Chemical Engineering 5 C(2017) 3181–31893183).  Phosphate, a finite and dwindling resource mined from phosphate rock, is a critical nutrient in modern agriculture, which is applied as fertilizer to ensure adequate plant growth. The inventors provide a cost-effective, environmentally-friendly method for recovering phosphate from agricultural runoff and other wastewater and delivering the recovered phosphate in a targeted and controlled manner to agriculture and farm sectors.

  • Go to Page: