Emissions Cause Delay in Rainfall
Rising greenhouse gases and declining aerosols have triggered an approximate four-day delay in rainfall over tropical land and the Sahel.
Human-Generated Compounds Spur Particle Formation over Southern Great Plains
Atmospheric aerosol particles modulate climate and the Earth’s energy balance by scattering and absorbing sunlight. They also seed clouds, acting as cloud condensation nuclei.
TOROIDAL MULTIPASS ABSORPTION DEVICE
U.S. Patent No. 7,876,443 and references therein discloses a method of creating a multipass cell having a toroidal configuration in which light is injected into the cavity via a hole or penetration into the wall of the reflective toroidal surface. Subsequent to this, a similar cavity is described in the scientific literature that provides additional design guidance for constructing a typical cell.[i],[ii] Both of the referenced papers also describe an absorbing mask that is placed against the cell wall to suppress unwanted reflections which the authors state contribute to coherent noise, often referred to as 'fringing" as the main laser beam interferes with stray reflections that can occur if the launch angle into the cell does not adhere to the value determined by the design equations. These interference patterns contribute noise to the desired signal and degrade the instrument's sensitivity. We disclose an alternate method of injecting light into a toroidal multipass cell using a small mirror (either plane or with optical power) affixed to the wall of the cell in place of a hole or penetration. This approach simplifies construction and offers a path to reduced construction costs and potential replication methods such as casting, injection molding, 3D printing, electroforming or metal spinning. [i] B. Tuzson, M. Mangold, H. Looser, A. Manninen, and L. Emmenegger, 'Compact multipass optical cell for laser spectroscopy", Opt. Lett., Vol 38 (3), 257-259 (2013) [ii] M. Mangold, B. Tuzson, M. Hundt, J. Jagerska, H. Looser, and L. Emmenegger, 'Circular paraboloid reflection cell for laser spectroscopic gas analysis", JOSA A, Vol. 33 (5), 913-919 (2016). U.S. Patent No. 7,876,443 and references therein discloses a method of creating a multipass cell having a toroidal configuration in which light is injected into the cavity via a hole or penetration into the wall of the reflective toroidal surface. Subsequent to this, a similar cavity is described in the scientific literature that provides additional design guidance for constructing a typical cell.[i],[ii] Both of the referenced papers also describe an absorbing mask that is placed against the cell wall to suppress unwanted reflections which the authors state contribute to coherent noise, often referred to as 'fringing" as the main laser beam interferes with stray reflections that can occur if the launch angle into the cell does not adhere to the value determined by the design equations. These interference patterns contribute noise to the desired signal and degrade the instrument's sensitivity. We disclose an alternate method of injecting light into a toroidal multipass cell using a small mirror (either plane or with optical power) affixed to the wall of the cell in place of a hole or penetration. This approach simplifies construction and offers a path to reduced construction costs and potential replication methods such as casting, injection molding, 3D printing, electroforming or metal spinning. [i] B. Tuzson, M. Mangold, H. Looser, A. Manninen, and L. Emmenegger, 'Compact multipass optical cell for laser spectroscopy", Opt. Lett., Vol 38 (3), 257-259 (2013) [ii] M. Mangold, B. Tuzson, M. Hundt, J. Jagerska, H. Looser, and L. Emmenegger, 'Circular paraboloid reflection cell for laser spectroscopic gas analysis", JOSA A, Vol. 33 (5), 913-919 (2016).
Wu Receives Outstanding Contribution Award
Earth Scientist Mingxuan Wu was recognized with an Outstanding Contribution Award for his work on nitrate aerosol modeling in the Energy Exascale Earth System Model.
Amazon Rainforest Foliage Gases Affect the Earth’s Atmosphere
PNNL researchers have uncovered a plant-derived process that leads to the formation of aerosol particles over the Amazon rainforest and potentially other forested parts of the world.
Method and Apparatus for Concentrating Vapors for Analysis
The addition of a thermally-desorbed, small-volume, solid-sorbent preconcentrator prior to real-time chemical sensor measurement of organic vapors can improve sensitivity and the initiation of the heating defines when analytes are delivered to the analytical system. Systems using preconcentrator can provide detection levels that are 10-1000 times lower than systems using direct sampling and analysis. During operation, a small volume of solid sorbent material collects chemicals from a large gas sample (e.g., at a given flow rate for a fixed period of time) and then releases the chemical(s) into a small gas volume during thermal desorption. This results in a concentrated chemical pulse that generates a rapid peak in the detector response. The signal before and after this peak is used as the baseline. Thus the process provides preconcentration, sample injection, and signal modulation functions. This signal modulation overcomes difficulties with baseline drift and sensor re-zeroing, and facilitates automated feature extraction, i.e., determining the magnitude of the response from the temporal data stream. These features are particularly useful for continuous unattended monitoring applications.
Method and Apparatus for Concentrating Vapors for Analysis
The addition of a thermally-desorbed, small-volume, solid-sorbent preconcentrator prior to real-time chemical sensor measurement of organic vapors can improve sensitivity and the initiation of the heating defines when analytes are delivered to the analytical system. Systems using preconcentrator can provide detection levels that are 10-1000 times lower than systems using direct sampling and analysis. During operation, a small volume of solid sorbent material collects chemicals from a large gas sample (e.g., at a given flow rate for a fixed period of time) and then releases the chemical(s) into a small gas volume during thermal desorption. This results in a concentrated chemical pulse that generates a rapid peak in the detector response. The signal before and after this peak is used as the baseline. Thus the process provides preconcentration, sample injection, and signal modulation functions. This signal modulation overcomes difficulties with baseline drift and sensor re-zeroing, and facilitates automated feature extraction, i.e., determining the magnitude of the response from the temporal data stream. These features are particularly useful for continuous unattended monitoring applications.
E4D (FERM3D) version 1.0
Electrical resistivity tomography ERT is a method of imaging the electrical conductivity of the subsurface. Electrical conductivity is a useful metric for understanding the subsurface because it is governed by geomechanical and geochemical properties that drive subsurface systems. ERT works by injecting current into the subsurface across a pair of electrodes, and measuring the corresponding electrical potential response across another pair of electrodes. Many such measurements are strategically taken across an array of electrodes to produce an ERT data set. These data are then processed through a computationally demanding process known as inversion to produce an image of the subsurface conductivity structure that gave rise to the measurements. Data can be inverted to provide 2D images, 3D images, or in the case of time-lapse 3D imaging, 4D images. Modern ERT data collection hardware can provide massive amounts of data in short periods of time. Owing to the computional demands of inverting ERT data to produce subsurface images, it is typically impossible to extract all of the resolution provided by these systems without the use of distributed memory parallel computing resources. FERM3D is the first (and to date only) fully parallel ERT inversion software available, and was developed specifically to address the computational demands of high resolution 3D and 4D subsurface imaging. All major computational efforts are fully parallelized in terms of both cpu effort and memory distribution, providing excellent scalability. Several new parallel algorithms were developed to address parallelization issues custom to the ERT/IPT inversion problem. The code utilizes highly flexible unstructured tetrahedral meshes, enabling advance imaging options such as the inclusion of known subsurface structures and advanced customized inversion constraints. In addition, F3D provides automonous 4D imaging capability. This capability was recently used to image a subsurface ammendment injection in 3D and in real-time, demonstrating the first real-time ERT imaging application in 2D or 3D.
Production of bio-based materials using photobioreactors with binary cultures
Solar energy is renewable, whereas all other fuels including those of fossil and nuclear origins are limited in amount and are exhaustible. One efficient method of capturing solar energy is through the use of the photosynthetic process to produce biomass (a renewable raw material resource for the production of food, fuel and chemicals) through appropriate conversions. There is currently great interest in using microalgae for the production of biofuels, mainly due to the fact that microalgae can produce biofuels at a much higher productivity than conventional plants and that they can be cultivated in aquatic environments, including seawater, and not compete for land resources with conventional agriculture. There are a number of limitations that hamper the current cultivation techniques used for algal biomass production; most important are high costs associated with increasing the mass transfer and by-product (O2) removal. The invention described here provides a cost-efficient way to eliminate problems associated with CO2 delivery and O2 removal. It is based on utilizing a consortium of microorganisms that produces large quantities of high-value biomass and/or valued metabolic byproducts by utilizing sun light, atmospheric CO2 and organic matter. As a proof of principle, we have used a binary culture of a photoautotrophic cyanobacterium and a heterotrophic bacterium and cultivated it in a non-aerated photobioreactor with only minimal addition of organic C. During this process, the binary culture produced higher amounts of microalgal biomass without air sparging (to remove O2 produced during photosynthesis) or additional CO2 injections. Utilization of binary cultures of phototrophic organisms opens new perspectives for designing efficient and cost effective production processes and means of directing carbon and nutrients from CO2 and waste towards algal production of biofuels: lipids, hydrocarbons.