Results for “ABA” — Page 13

DOE OSTI2021

Detection of the Metabolic Response to Drought Stress Using Hyperspectral Reflectance

Drought is the most important limitation on crop yield. Understanding and detecting drought stress in crops is vital for improving water use efficiency through effective breeding and management. Leaf reflectance spectroscopy offers a rapid, non-destructive alternative to traditional techniques for measuring plant traits involved in a drought response. We measured drought stress in six glasshouse-grown agronomic species using physiological, biochemical and spectral data. In contrast to physiological traits, leaf metabolite concentrations revealed drought stress before it was visible to the naked eye. We used full-spectrum leaf reflectance data to predict metabolite concentrations using partial least-squares regression, with validation R2 values of 0.49 to 0.87. We show for the first time that spectroscopy may be used for the quantitative estimation of proline and abscisic acid, demonstrating the first use of hyperspectral data to detect a phytohormone. We used linear discriminant analysis and partial least squares discriminant analysis to differentiate between droughted and watered plants based on measured traits (accuracy: 71%) and raw spectral data (66%). Finally, we validated our glasshouse-developed models in an independent field trial. We demonstrate that spectroscopy can detect drought stress via underlying biochemical changes, before visual differences occur, representing a powerful advance for measuring limitations on yield.

54 ENVIRONMENTAL SCIENCES↗

DOE OSTI2020

Conjugate Heat Transfer Analysis of the Supercritical CO2 Based Counter Flow Compact 3D Heat Exchangers

Compact heat exchangers using supercritical fluids such as CO2 are preferred due to their high heat transfer capacity and smaller footprint. Three-dimensional conjugate forced convection heat transfer analysis was performed on several shell-and-tube counter-flow microchannel heat exchangers. Numerical simulations were conducted to test effect of change in mass flow rate, hydraulic diameter and various cross sections on the heat transfer. Increasing mass flow rate improved heat transfer up to a maximum value and then decreased downstream with increasing turbulence. Maximum heat transfer was obtained for the micro channel with the smallest hydraulic diameter. Amongst the cross sections analyzed (circular, square, circular with radial ribs, and square with radial ribs), the most uniform distribution of temperature and maximum heat transfer were obtained for circular cross section with radial ribs. An optimally efficient operation of such a heat exchanger can be attained by considering these factors during multi-objective constrained optimization of geometric parameters and requirements for additive manufacturing of such compact heat exchangers.

Chitale, Janhavi↗

DOE OSTI2019

US Hybrid Northeast Demonstration and Deployment of FCRxNV200 (DE-EE0007276 Final Report)

In this project, US Hybrid and other strategic project partners, collaborated to build a fuel cell range extended plug-in hybrid utility vehicle and demonstrate it in real-world operation. The base vehicle platform to be modified to the hybrid platform was the Nissan e-NV200, which is an all-electric version of the NV200 commercial cargo van. This is a Class 1 vehicle with a GVWR of approx. 4,900 lbs., wheelbase of 115 inches, and cargo capacity of approx. 122ft. The 80kW/254N-m electric powertrain is the same as Nissan’s LEAF, but with a revised final drive ratio (9.301 vs. 8.194) to accommodate higher payloads with lower top speed. US Hybrid utilized a purpose built, freeze capable, integrated fuel cell engine FCe™10 to hybridize and range-extend the existing e-NV200 vehicle with OEM drivetrain. The eNV200 has the same size battery as the LEAF with a different rear axle ratio. Fuel cell stack size and balance of plant (BOP) configuration were designed for compact under the hood vehicle packaging. Engine design took into consideration the need for high efficiency (>50% at all loads & up to 62% at partial power), optimal heat recovery for cabin heating, and low maintenance. The technology of the isolated DC-DC converter operating at >100kHz enables extremely high efficiency (ZVS and SIC power devices) and robust performance while reducing system complexity, weight, and volume. This enables an extended vehicle range of up to 250 miles and an operational life that should provide lower total cost of ownership (TCO) to the end user.

33 ADVANCED PROPULSION SYSTEMS↗

DOE OSTI2014

Plant chemical biology: are we meeting the promise?

As an early adopter of plant chemical genetics to the study of endomembrane trafficking, we have observed the growth of small molecule approaches. Within the field, we often describe the strengths of the approach in a broad, generic manner, such as the ability to address redundancy and lethality. But, we are now in a much better position to evaluate the demonstrated value of the approach based on examples. In this perspective, we offer an assessment of chemical genetics in plants and where its applications may be of particular utility from the perspective of the cell biologist. Beyond this, we suggest areas to be addressed to provide broader access and enhance the effectiveness of small molecule approaches in plant biology.

54 ENVIRONMENTAL SCIENCES↗

DOE OSTI2015

Non-permeable substrate carrier for electroplating

One embodiment relates to a substrate carrier for use in electroplating a plurality of substrates. The substrate carrier comprises a non-conductive carrier body on which the substrates are to be held. Electrically-conductive lines are embedded within the carrier body, and a plurality of contact clips are coupled to the electrically-conductive lines embedded within the carrier body. The contact clips hold the substrates in place and electrically couple the substrates to the electrically-conductive lines. The non-conductive carrier body is continuous so as to be impermeable to flow of electroplating solution through the non-conductive carrier body. Other embodiments, aspects and features are also disclosed.

36 MATERIALS SCIENCE↗

DOE OSTI2016

Maintainable substrate carrier for electroplating

One embodiment relates to a substrate carrier for use in electroplating a plurality of substrates. The carrier includes a non-conductive carrier body on which the substrates are placed and conductive lines embedded within the carrier body. A plurality of conductive clip attachment parts are attached in a permanent manner to the conductive lines embedded within the carrier body. A plurality of contact clips are attached in a removable manner to the clip attachment parts. The contact clips hold the substrates in place and conductively connecting the substrates with the conductive lines. Other embodiments, aspects and features are also disclosed.

36 MATERIALS SCIENCE↗

DOE OSTI2016

Fuel Cell-Battery Electric Hybrid for Utility or Municipal MD or HD Bucket Trucks. Fuel Cell powered Auxiliary Power Module “APM” I Final Scientific/Technical Report

Explore the source record for details and available documents.

30 DIRECT ENERGY CONVERSION↗

DOE OSTI2014

Edge coating apparatus for solar cell substrates

A non-contact edge coating apparatus applies coating material to an edge of a non-circular solar cell substrate without physical contact. The apparatus may include a rotatable substrate support configured to hold the substrate. The apparatus may further include an applicator configured to receive a coating material and apply the coating material to an edge of the substrate while the substrate is rotated without any portion of the applicator physically touching the edge of the substrate. The substrate support may be mechanically coupled to a cam, which contacts a follower mechanically coupled to the applicator. A variety of coating materials may be employed with the apparatus including hot melt ink and UV curable plating resist.

14 SOLAR ENERGY↗

DOE OSTI2020

Conjugate Heat Transfer Analysis of the Supercritical CO2 Based Counter Flow Compact 3D Heat Exchangers

Compact heat exchangers using supercritical fluids such as CO2 are preferred due to their high heat transfer capacity and smaller footprint. Three-dimensional conjugate forced convection heat transfer analysis was performed on several shell-and-tube counter-flow microchannel heat exchangers. Numerical simulations were conducted to test effect of change in mass flow rate, hydraulic diameter and various cross sections on the heat transfer. Increasing mass flow rate improved heat transfer up to a maximum value and then decreased downstream with increasing turbulence. Maximum heat transfer was obtained for the micro channel with the smallest hydraulic diameter. Amongst the cross sections analyzed (circular, square, circular with radial ribs, and square with radial ribs), the most uniform distribution of temperature and maximum heat transfer were obtained for circular cross section with radial ribs. An optimally efficient operation of such a heat exchanger can be attained by considering these factors during multi-objective constrained optimization of geometric parameters and requirements for additive manufacturing of such compact heat exchangers.

Chitale, Janhavi↗

DOE OSTI2022

Non-permeable substrate carrier for electroplating

One embodiment relates to a substrate carrier for use in electroplating a plurality of substrates. The substrate carrier comprises a non-conductive carrier body on which the substrates are to be held. Electrically-conductive lines are embedded within the carrier body, and a plurality of contact clips are coupled to the electrically-conductive lines embedded within the carrier body. The contact clips hold the substrates in place and electrically couple the substrates to the electrically-conductive lines. The non-conductive carrier body is continuous so as to be impermeable to flow of electroplating solution through the non-conductive carrier body. Other embodiments, aspects and features are also disclosed.

42 ENGINEERING↗