Burns S.P.,University of Colorado at Boulder |
Burns S.P.,U.S. National Center for Atmospheric Research |
Blanken P.D.,University of Colorado at Boulder |
Turnipseed A.A.,2B Technologies, Inc. |
And 2 more authors.
Biogeosciences | Year: 2015
Precipitation changes the physical and biological characteristics of an ecosystem. Using a precipitation-based conditional sampling technique and a 14 year data set from a 25 m micrometeorological tower in a high-elevation subalpine forest, we examined how warm-season precipitation affected the above-canopy diel cycle of wind and turbulence, net radiation Rnet, ecosystem eddy covariance fluxes (sensible heat H, latent heat LE, and CO2 net ecosystem exchange NEE) and vertical profiles of scalars (air temperature Ta, specific humidity q, and CO2 dry mole fraction χc). This analysis allowed us to examine how precipitation modified these variables from hourly (i.e., the diel cycle) to multi-day time-scales (i.e., typical of a weather-system frontal passage). During mid-day we found the following: (i) even though precipitation caused mean changes on the order of 50-70 % to Rnet, H, and LE, the surface energy balance (SEB) was relatively insensitive to precipitation with mid-day closure values ranging between 90 and 110 %, and (ii) compared to a typical dry day, a day following a rainy day was characterized by increased ecosystem uptake of CO2 (NEE increased by ≈ 10 %), enhanced evaporative cooling (mid-day LE increased by ≈ 30 W m-2), and a smaller amount of sensible heat transfer (mid-day H decreased by ≈ 70 W m-2). Based on the mean diel cycle, the evaporative contribution to total evapotranspiration was, on average, around 6 % in dry conditions and between 15 and 25 % in partially wet conditions. Furthermore, increased LE lasted at least 18 h following a rain event. At night, even though precipitation (and accompanying clouds) reduced the magnitude of Rnet, LE increased from ≈ 10 to over 20 W m-2 due to increased evaporation. Any effect of precipitation on the nocturnal SEB closure and NEE was overshadowed by atmospheric phenomena such as horizontal advection and decoupling that create measurement difficulties. Above-canopy mean χc during wet conditions was found to be about 2-3 μmol mol-1 larger than χc on dry days. This difference was fairly constant over the full diel cycle suggesting that it was due to synoptic weather patterns (different air masses and/or effects of barometric pressure). Finally, the effect of clouds on the timing and magnitude of daytime ecosystem fluxes is described. © 2015 Author(s).
Andersen P.C.,2B Technologies, Inc. |
Williford C.J.,2B Technologies, Inc. |
David D.E.,University of Colorado at Boulder |
Birks J.W.,2B Technologies, Inc.
Analytical Chemistry | Year: 2010
A new instrument for monitoring atmospheric CO2 has been developed based on the measurement of the speed of sound in air. The instrument uses a selective scrubber to yield highly precise and accurate measurements of CO2 mixing ratios at ambient concentrations. The instrument has a precision of 0.3 ppmv (1′) with a signal that is independent of pressure and requires a flow rate of only 30 mL/min. Laboratory measurements of atmospheric CO2 showed excellent agreement with values obtained by nondispersive infrared absorption. The instrument has the advantage of collecting continuous, high-precision data every 25 s and can be modified for vertical profiling studies using kites, balloons, or light aircraft for the purpose of measuring landscape-scale fluxes. © 2010 American Chemical Society.
Andersen P.C.,2B Technologies, Inc. |
Williford C.J.,2B Technologies, Inc. |
Birks J.W.,2B Technologies, Inc.
Analytical Chemistry | Year: 2010
A new portable instrument has been developed that offers rapid detection of ozone at the parts per billion (ppb) level for personal exposure monitoring. The personal ozone monitor is based on the EPA Federal Reference Method of UV absorbance and has the advantage of being small (10 cm×7.6 cm×3.8 cm), lightweight (0.3 kg), low power (2.9 W), and battery-operated. The instrument can be worn by an individual during normal daily activities because it is unaffected by humidity, physical orientation, temperature, and vibration. In order to eliminate any significant interference from water vapor, Nafion tubing was installed before the detection cell, and the optical path was lined with quartz. A precision of 1.5 parts per billion by volume (ppbv) and limit of detection of 4.5 ppbv (S/N = 3) was demonstrated with the instrument making measurements every 10 s. © 2010 American Chemical Society.
Arien Y.,2B Technologies, Inc. |
Dixon P.,Laird Technologies |
Khorrami M.,Laird Technologies |
Degraeve A.,Catholic University of Leuven |
Pissoort D.,Catholic University of Leuven
IEEE International Symposium on Electromagnetic Compatibility | Year: 2015
This paper describes a study on the effectiveness of grounding pins and high-frequency absorbers to reduce the emissions of heatsinks up to 20 GHz. The study considers four different types of excitations, namely a direct excitation, an excitation by a patch antenna, an excitation by a microstrip below the center of the heatsink, and an excitation by a microstrip that was off-set with respect to the center of the heatsink. Grounding post are positioned equidistantly along the edges of the heatsink and the number of grounding pins per side is varied. Adding grounding pins significantly reduces the emission of the heatsink below 1-2 GHz. At higher frequencies, they lose their capability to reduce the heatsink emission and even introduce extra resonance frequencies where the emission is higher compared to the ungrounded heatsink. Three different possible arrangements for the application of absorbing material were considered, namely a thin flat absorber just below the heatsink, a ring absorber between the heatsink and the PCB, and a collar absorber around the heatsink. The absorber succeeds in reducing the heatsink's emission above 1-2 GHz, but has little of no positive effect on the emissions below 1-2 GHz. Only by the combination of the grounding pins and the absorber material, a reduction of the heatsink's emission is achieved over the full frequency range. © 2015 IEEE.
2B Technologies, Inc. | Date: 2015-06-26
The present invention provides a means of measuring the concentration of ozone dissolved in water or another solvent. Small, discrete samples are sparged with air or another unreactive gas for a short period of time to measure a profile of ozone vs time in the sparge gas. The total amount of ozone in the original sample is obtained by integrating under the ozone vs time profile. A correction may be made for ozone remaining in the sample after a finite sparge time by integrating under the profile tail using a decay constant obtained from the measured ozone vs time profile. The method differs from previous methods based on sparging of the sample in that a Henrys Law equilibrium or constant ratio of ozone present in the gas and liquid phases is not assumed and the flow rates of sample and sparge gas are not continuous. Instead, discrete samples are analyzed by nearly complete sparging. The new method is applicable to dirty (impure) water because the ozone is measured in the absence of UV-absorbing and scattering impurities that may be present in the sample. The method applies to high purity water as well.
2B Technologies, Inc. | Date: 2015-07-27
The present invention provides a means of greatly reducing interferences from mercury vapor, UV-absorbing compounds and water vapor in the measurement of ozone by UV absorbance. A heated graphite scrubber destroys greater than 99% of ozone passing through it while reducing biases from typical atmospheric UV-absorbing interferents by large factors compared to conventional ozone scrubbers. Substitution of a heated graphite scrubber in place of traditional ozone scrubbers such as hopcalite, metal oxides and heated silver scrubbers, results in a more accurate measurement of ozone by reducing the responses to UV-absorbing interferences and water vapor. The heated graphite scrubber also may be used in combination with other ozone sensors, such as electrochemical and HMOS sensors, to provide a reference measurement with ozone selectively removed and thus greatly reduce contributions from interfering species in those measurement devices as well.
Agency: Department of Health and Human Services | Branch: | Program: SBIR | Phase: Phase I | Award Amount: 149.69K | Year: 2014
DESCRIPTION (provided by applicant): We propose to make air pollution personal by enabling K-12 students to act as citizen scientists using sophisticated, mobile air pollution monitors to measure their individual exposures to black carbon, a primary pollutant, and ozone, a secondary pollutant. Through their experiments and specially designed curricula, students will learn when and where they and others are exposed to these damaging air pollutants and how that exposure can affect their health. Ozone and black carbon are two of the most damaging air pollutants to human health, and it has been shown that both are asthma triggers and can lead to other health problems, including heart disease and even premature death. Heightened awareness of the way air quality impacts health is vital, and nothing is more impactful than understanding exposure at a personal level. Through our nonprofit partner the GO3 Project, ~50 schools will be loaned a 2B Tech Personal Ozone Monitor (POM) and microAeth personal black carbon
Agency: Department of Health and Human Services | Branch: National Institutes of Health | Program: SBIR | Phase: Phase II | Award Amount: 984.18K | Year: 2015
DESCRIPTION provided by applicant Personal Exposure Monitoring of Air Pollutants as an Educational Tool in the GO Treks project launched by the Phase I grant students at schools throughout the U S used personal monitors to measure the air pollutants black carbon and ozone along treks of their own design The treks were uploaded to blogs in the GO website where they were displayed on Google Earth and where students teachers GO staff and air quality scientists discussed the results The students learned about the sources transformations and sinks of air pollutants by acting as citizen scientists forming and testing their own hypotheses using real scientific instruments Highlights include comparisons of rural vs urban exposures discovery of increased pollution levels during pick up drop off traffic at schools comparisons of pollutant levels along busy and residential streets analysis of exposures during commutes to school a trek at a hydraulic fracturing site treks from urban areas into the mountains and investigation of emissions from different types of sources such as lawnmowers and buses One school explored an area that is known to have an underground coal mine fire and even launched the ozone monitor on a balloon to km ft where ozone in the stratosphere was measured We propose to improve upon and expand GO Treks in the Phase II project by implementing a quality assurance QA program for GO Treks data developing a universal Personal Air Monitoring Module PAMM that will allow any air quality sensor to upload data in real time to GO Treks via a smart phone app expanding the suite of miniaturized instruments available to GO Treks to include CO and Equivalent PM in addition to O and black carbon and revising the GO online curriculum to be smaller andquot bite sizedandquot modules each of which can be completing in an hour or less and awarding digital badges for completion of each module Individuals who earn all GO Air Quality digital badges including those awarded for participation in a trek and for achieving a prescribed level of activit on the GO network will be awarded a Mozilla Open Badge that can be included in their digital resume The commercialization plan expands GO Treks to include citizen monitoring by environmental advocates and local government agencies in addition to schools and proposes rental of instruments at a fee of only $ week A business model is proposed that provides exponential growth of the project by continuous reinvestment of all but of profit in new inventory Model results using reasonable assumptions show that in four years GO Treks could be grown to annual rentals of $ M with servicing of organizations from an inventory of instruments PUBLIC HEALTH RELEVANCE The GO Treks project allows citizen scientists including students hobbyists environmental advocates and local government officials to measure air pollutants such as ozone black carbon particulate matter PM and CO along treks in their local communities A Personal Air Monitoring Module PAMM will allow measurements made using any air quality sensor to be uploaded via a cell phone app for display on Google Earth within a public blog for data sharing and public discussion
Agency: Department of Health and Human Services | Branch: | Program: SBIR | Phase: Phase II | Award Amount: 736.23K | Year: 2010
DESCRIPTION (provided by applicant): In this proposal we respond to the call by the National Institute of Environmental Health Sciences (NIEHS) in the PHS 2009-2 Omnibus Solicitation, Exposure Biology Program, Section 1, Technologies for Generating Precise Measures of Environmental Exposures for new products/devices, tools, assays to improve our ability to precisely measure environmental exposures to individuals with high temporal and spatial resolution. According to the solicitation, the device should be of appropriate scale to be field deployable and/or wearable. Ozone, formed in photochemical air pollution, has well documented adverse effects on human health, including reduction of lung function and aggravation of preexisting respiratory disease such as asthma. Emergency department visits, daily hospital admissions and mortality increase during episodes of high ozone concentration. A Personal Ozone Monitor (POM) is required for environmental health studies of the physiological effects of ozone and for validating computer models of human exposure. In the Phase I project we successfully developed a small (4 x 3 x 1.5 inch), light weight (0.7 lb), low power (2.9 watts), low cost ( 795 in parts), battery-operated POM based on the well established method of UV absorbance (an EPA Federal Reference Method). The pocket-sized POM has a precision and accuracy of # 2 ppb, makes new measurements every 10 s and has an internal data logger for downloading data to a personal computer. During the Phase II project proposed here, we will further improve and finalize the development of the POM to include the following: 1) dedicated ground plane on the printed circuit board to further reduce noise, 2) ruggedized, easily manufactured enclosure, 3) human interface consisting of liquid crystal display and keypad, 4) docking station with battery charger, 5) GPS for co-locating measurements with geographical coordinates, and 6) wireless communication between the POM and docking station. Firmware will be developed to support the new functions, and software will be developed for data acquisition and graphing by a computer and for uploading ozone data to the web. The efficacy and accuracy of the POM will be evaluated in personal exposure monitoring studies conducted at the Environmental and Occupational Health Sciences Institute (EOHSI) of the University of Medicine and Dentistry of New Jersey. Several large markets for a pocket-sized ozone monitor have been identified in addition to personal ozone monitoring; these include rapidly growing industrial applications of ozone and the Global Ozone (GO3) Project, an international educational project in which high school students build and operate an ozone monitoring station and share their data as an overlay on the Google Earth map. PUBLIC HEALTH RELEVANCE: Development of a pocket-sized, battery powered Personal Ozone Monitor (POM) will be completed and evaluated as a means of measuring the time-resolved exposure of individuals during normal daily activities. The POM will facilitate physiological studies of the adverse effects of ozone, formed in air pollution, on human health.
PubMed | 2B Technologies, Inc., University of Piemonte Orientale and University of Milan
Type: | Journal: European journal of pharmaceutical sciences : official journal of the European Federation for Pharmaceutical Sciences | Year: 2016
Itraconazole (ITZ) nanocrystal-containing powders were prepared through the combined use of high pressure homogenization (HPH) and spray drying (SD). These powders were intended as base materials for the preparation of extemporary oral suspensions of the drug. The role and the effect of stabilizers on the size of re-dispersed particles were studied using a mixture design and a Scheff model relating the dried nanosuspension composition to the mean particle diameters. The homogenization process required a surface active agent (Tween 20) to obtain the efficient comminution of itraconazole micronized powder. SD was carried out on ITZ nanosuspensions after addition of a cellulose derivative (Methocel() E5) that allowed the prompt re-dispersion of nanoparticles under in use conditions. The powders obtained by drying of homogenized systems showed in vitro dissolution profile faster than that of the micronized drug, suggesting a potential ameliorated GI absorption of itraconazole released from the nanosuspensions.