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.
Earth Scientist, Hailong Wang, PhD
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.
Ion focusing device
Sensitive measurements in mass spectrometer (MS) relies on the efficient ion utilization and minimizing losses at the different components of the MS. As ion trajectories depend on multiple factors such as confinement fields, gas dynamics, and physical alignment of various MS ion optics it is crucial to develop MS ion optics that transfer ions efficiently. This is specially the case where the geometries of the ion optics at the interface are different such that the electric field do not match causing to ion losses. Here, we disclose a novel device to efficiently transfer and guide ions into entrance of a planar ion guide or ion optics element. The new device has a planar geometry and consists of two surfaces held at an angle to each other. Importantly the electric field generated in this new device is synchronized and smoothly matches the electric field at downstream ion optics element. The result is ions transmit through the interface with no loss. On each surface of the new device the electrodes are arranged into a converging shape to guide ions from any position at the entrance into the end of the device. Such device also relief the engineering constraints on precise alignment of ion optics at the interface which greatly reduce the cost of building such platforms. Such device can be also used as injection mechanism to e.g. time of flight mass spectrometer pulsar region as the geometry of the ion beam exiting this new device can perfectly match the
New Joint Appointees Build Research Impact at PNNL
PNNL welcomes new joint appointments to expand the research productivity and scientific impact of both PNNL and the university partners, broadening the base of expertise at each institution and helping to build interdisciplinary teams.
Idrobo Named Microscopy Society of America Fellow
Juan Carlos Idrobo, a joint appointee with the University of Washington, was elected a fellow of the Microscopy Society of America.