24 research outputs found
Would You Share? Examining How Knowledge Type and Communication Channel Influence Knowledge Sharing
Due to recent advances in computer-mediated communication technologies, individuals are able to communicate through a variety of channels to exchange knowledge. This paper extends prior research to include a comparison of knowledge exchange through face-to-face and computer-mediated communication environments (e-mail, electronic community, and electronic knowledge repository) for different knowledge types (computer program and expertise). Using social exchange theory, hypotheses are proposed based on the degree of an individualâs expectations of reciprocity and how this influences an individualâs knowledge sharing decision. Using vignettes adapted from prior empirical research, this study determines whether individuals adjust their knowledge sharing behaviors based on the different types of knowledge and the communication channel used. Results suggest that electronic knowledge repository and face-to-face are the preferred environments for sharing expertise and electronic knowledge repositories are preferred for sharing a computer program
The Impact of IT Structure and Firm Interdependency on Relational Rents in Innovation Collaboration Networks
This paper examines inter-organizational innovation collaboration networks (ICNs) using a relational view of the firm perspective. This study suggests that information technology (IT) structure and firm interdependencies can be significant predictors of relational rent generation for innovation collaboration networks. Furthermore, the authors argue that the alignment of these structural properties â IT structure and firm interdependency - will influence firm performance in terms of relational rents obtained by the innovation collaboration network. The relevant literature will be discussed and hypotheses proposed to empirically examine the relationship between IT structure and firm interdependencies on relational rent generation. Potential theoretical contributions to the relational view of the firm are identified and discussed. Limitations of the proposed study and discussion of the future research opportunities will also be provided
First direct measurements of formaldehyde flux via eddy covariance: implications for missing in-canopy formaldehyde sources
We report the first observations of formaldehyde (HCHO) flux measured via eddy covariance, as well as HCHO concentrations and gradients, as observed by the Madison Fiber Laser-Induced Fluorescence Instrument during the BEACHON-ROCS 2010 campaign in a rural, Ponderosa Pine forest northwest of Colorado Springs, CO. A median noon upward flux of ~80 &mu;g m<sup>&minus;2</sup> h<sup>&minus;1</sup> (~24 ppt<sub>v</sub> m s<sup>&minus;1</sup>) was observed with a noon range of 37 to 131 &mu;g m<sup>&minus;2</sup> h<sup>&minus;1</sup>. Enclosure experiments were performed to determine the HCHO branch (3.5 &mu;g m<sup>-2</sup> h<sup>&minus;1</sup>) and soil (7.3 &mu;g m<sup>&minus;2</sup> h<sup>&minus;1</sup>) direct emission rates in the canopy. A zero-dimensional canopy box model, used to determine the apportionment of HCHO source and sink contributions to the flux, underpredicted the observed HCHO flux by a factor of 6. Simulated increases in concentrations of species similar to monoterpenes resulted in poor agreement with measurements, while simulated increases in direct HCHO emissions and/or concentrations of species similar to 2-methyl-3-buten-2-ol best improved model/measurement agreement. Given the typical diurnal variability of these BVOC emissions and direct HCHO emissions, this suggests that the source of the missing flux is a process with both a strong temperature and radiation dependence
Missing OH reactivity in the global marine boundary layer
The hydroxyl radical (OH) reacts with thousands of chemical species in the atmosphere, initiating their removal and the chemical reaction sequences that produce ozone, secondary aerosols, and gas-phase acids. OH reactivity, which is the inverse of OH lifetime, influences the OH abundance and the ability of OH to cleanse the atmosphere. The NASA Atmospheric Tomography (ATom) campaign used instruments on the NASA DC-8 aircraft to measure OH reactivity and more than 100 trace chemical species. ATom presented a unique opportunity to test the completeness of the OH reactivity calculated from the chemical species measurements by comparing it to the measured OH reactivity over two oceans across four seasons. Although the calculated OH reactivity was below the limit of detection for the ATom instrument used to measure OH reactivity throughout much of the free troposphere, the instrument was able to measure the OH reactivity in and just above the marine boundary layer. The mean measured value of OH reactivity in the marine boundary layer across all latitudes and all ATom deployments was 1.9âsâ»Âč, which is 0.5âsâ»Âč larger than the mean calculated OH reactivity. The missing OH reactivity, the difference between the measured and calculated OH reactivity, varied between 0 and 3.5âsâ»Âč, with the highest values over the Northern Hemisphere Pacific Ocean. Correlations of missing OH reactivity with formaldehyde, dimethyl sulfide, butanal, and sea surface temperature suggest the presence of unmeasured or unknown volatile organic compounds or oxygenated volatile organic compounds associated with ocean emissions
The NASA Airborne Tropical TRopopause EXperiment (ATTREX): High-Altitude Aircraft Measurements in the Tropical Western Pacific
The February through March 2014 deployment of the NASA Airborne Tropical TRopopause EXperiment (ATTREX) provided unique in situ measurements in the western Pacific Tropical Tropopause Layer (TTL). Six flights were conducted from Guam with the long-range, high-altitude, unmanned Global Hawk aircraft. The ATTREX Global Hawk payload provided measurements of water vapor, meteorological conditions, cloud properties, tracer and chemical radical concentrations, and radiative fluxes. The campaign was partially coincident with the CONTRAST and CAST airborne campaigns based in Guam using lower-altitude aircraft (see companion articles in this issue). The ATTREX dataset is being used for investigations of TTL cloud, transport, dynamical, and chemical processes as well as for evaluation and improvement of global-model representations of TTL processes. The ATTREX data is openly available at https:espoarchive.nasa.gov
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Large hemispheric difference in nucleation mode aerosol concentrations in the lowermost stratosphere at mid- and high latitudes
The details of aerosol processes and size distributions in the stratosphere are important for both heterogeneous chemistry and aerosol–radiation interactions. Using in situ, global-scale measurements of the size distribution of particles with diameters > 3 nm from the NASA Atmospheric Tomography Mission (ATom), we identify a mode of aerosol smaller than 12 nm in the lowermost stratosphere (LMS) at mid- and high latitudes. This mode is substantial only in the Northern Hemisphere (NH) and was observed in all four seasons. We also observe elevated SO2, an important precursor for new particle formation (NPF) and growth, in the NH LMS. We use box modelling and thermodynamic calculations to show that NPF can occur in the LMS conditions observed on ATom. Aircraft emissions are shown as likely sources of this SO2, as well as a potential source of nucleation mode particles directly emitted by or formed in the plume of the engines. These nucleation mode particles have the potential to grow to larger sizes and to coagulate with larger aerosol, affecting heterogeneous chemistry and aerosol–radiation interactions. Understanding all sources and characteristics of stratospheric aerosols is important in the context of anthropogenic climate change as well as proposals for climate intervention via stratospheric sulfur injection. This analysis not only adds to the, currently sparse, observations of the global impact of aviation, but also introduces another aspect of climate influence, namely a size distribution shift of the background aerosol distribution in the LMS.
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First direct measurements of formaldehyde flux via eddy covariance: implications for missing in-canopy formaldehyde sources
We report the first observations of formaldehyde (HCHO) flux measured via eddy covariance, as well as HCHO concentrations and gradients, as observed by the Madison Fiber Laser-Induced Fluorescence Instrument during the BEACHON-ROCS 2010 campaign in a rural, Ponderosa Pine forest northwest of Colorado Springs, CO. A median noon upward flux of ~80 ÎŒg mâ2 hâ1 (~24 pptv m sâ1) was observed with a noon range of 37 to 131 ÎŒg mâ2 hâ1. Enclosure experiments were performed to determine the HCHO branch (3.5 ÎŒg m-2 hâ1) and soil (7.3 ÎŒg mâ2 hâ1) direct emission rates in the canopy. A zero-dimensional canopy box model, used to determine the apportionment of HCHO source and sink contributions to the flux, underpredicted the observed HCHO flux by a factor of 6. Simulated increases in concentrations of species similar to monoterpenes resulted in poor agreement with measurements, while simulated increases in direct HCHO emissions and/or concentrations of species similar to 2-methyl-3-buten-2-ol best improved model/measurement agreement. Given the typical diurnal variability of these BVOC emissions and direct HCHO emissions, this suggests that the source of the missing flux is a process with both a strong temperature and radiation dependence