Preliminary OARE absolute acceleration measurements on STS-50

On-orbit Orbital Acceleration Research Experiment (OARE) data on STS-50 was examined in detail during a 2-day time period. Absolute acceleration levels were derived at the OARE location, the orbiter center-of-gravity, and at the STS-50 spacelab Crystal Growth Facility. The tri-axial OARE raw acceleration measurements (i.e., telemetered data) during the interval were filtered using a sliding trimmed mean filter in order to remove large acceleration spikes (e.g., thrusters) and reduce the noise. Twelve OARE measured biases in each acceleration channel during the 2-day interval were analyzed and applied to the filtered data. Similarly, the in situ measured x-axis scale factors in the sensor's most sensitive range were also analyzed and applied to the data. Due to equipment problem(s) on this flight, both y- and z- axis sensitive range scale factors were determined in a separate process (using the OARE maneuver data) and subsequently applied to the data. All known significant low-frequency corrections at the OARE location (i.e., both vertical and horizontal gravity-gradient, and rotational effects) were removed from the filtered data in order to produce the acceleration components at the orbiter's center-of-gravity, which are the aerodynamic signals along each body axes. Results indicate that there is a force of unknown origin being applied to the Orbiter in addition to the aerodynamic forces. The OARE instrument and all known gravitational and electromagnetic forces were reexamined, but none produce the observed effect. Thus, it is tentatively concluded that the Orbiter is creating the environment observed

Zones of Gelatinous Fibers in Populus Balsamifera L.

Although balsam poplar (Populus balsamifera L.) is a logical supplement to the aspen (Fopulus tremuloides Michx.) resource for the manufacture of oriented strandboard (OSB), it has not been utilized extensively because of reported machining problems. The machining difficulties usually have been attributed to fibers with thick gelatinous layers in their cell walls. This study employed scanning electron microscopy (SEM) to observe the cell-wall structure of balsam poplar grown in Minnesota. In a previous study, balsam poplar samples were identified as difficult to waferize on the basis of wood fibers plugging the waferizing knives. The balsam poplar samples that were difficult to waferize often contained areas that appeared as "white rings" to the naked eye. Observation with the scanning electron microscope revealed that the "white rings" in the wood were zones that contained very high concentrations of gelatinous fibers. In these fibers, the cell wall typically consisted of a gelatinous layer that occupied 30 to 90% of the cell wall. In most cases, the initiation and termination of zones with high concentrations of gelatinous fibers took place within one annual growth increment or slightly more. Additional observation of trees within the sample showed that the "white rings" and the accompanying high concentrations of gelatinous layers were usually restricted to one side of the tree. This observation has led us to believe that the "white ring" areas and the corresponding zones of gelatinous fibers were the result of tension wood formation in the balsam poplar trees and not a part of normal wood formation

OARE flight maneuvers and calibration measurements on STS-58

The Orbital Acceleration Research Experiment (OARE), which has flown on STS-40, STS-50, and STS-58, contains a three axis accelerometer with a single, nonpendulous, electrostatically suspended proofmass which can resolve accelerations to the nano-g level. The experiment also contains a full calibration station to permit in situ bias and scale factor calibration. This on-orbit calibration capability eliminates the large uncertainty of ground-based calibrations encountered with accelerometers flown in the past on the orbiter, thus providing absolute acceleration measurement accuracy heretofore unachievable. This is the first time accelerometer scale factor measurements have been performed on orbit. A detailed analysis of the calibration process is given along with results of the calibration factors from the on-orbit OARE flight measurements on STS-58. In addition, the analysis of OARE flight maneuver data used to validate the scale factor measurements in the sensor's most sensitive range is also presented. Estimates on calibration uncertainties are discussed. This provides bounds on the STS-58 absolute acceleration measurements for future applications

The SED Machine: a dedicated transient IFU spectrograph

The Spectral Energy Distribution (SED) Machine is an Integral Field Unit (IFU) spectrograph designed specifically to classify transients. It is comprised of two subsystems. A lenselet based IFU, with a 26" × 26" Field of View (FoV) and ∼ 0.75" spaxels feeds a constant resolution (R∼100) triple-prism. The dispersed rays are than imaged onto an off-the-shelf CCD detector. The second subsystem, the Rainbow Camera (RC), is a 4-band seeing-limited imager with a 12.5' × 12.5' FoV around the IFU that will allow real time spectrophotometric calibrations with a ∼ 5% accuracy. Data from both subsystems will be processed in real time using a dedicated reduction pipeline. The SED Machine will be mounted on the Palomar 60-inch robotic telescope (P60), covers a wavelength range of 370 − 920nm at high throughput and will classify transients from on-going and future surveys at a high rate. This will provide good statistics for common types of transients, and a better ability to discover and study rare and exotic ones. We present the science cases, optical design, and data reduction strategy of the SED Machine. The SED machine is currently being constructed at the Calofornia Institute of Technology, and will be comissioned on the spring of 2013

Oxidation of Thiols to Disulfides using an Environmentally “Green” Organocatalyst and New Mechanistic Insights

The selective oxidation of thiols to disulfides is an area of great importance in the areas of materials and medicinal chemistry research. The production of polymers, rubber, pharmaceuticals, and the folding of proteins in biological systems all rely on the formation of disulfide bonds. Herein, we introduce a stoichiometric and electrocatalytic method for the oxidation of various pharmaceutically and biologically relevant thiols into their respective disulfides in more environmentally benign solvents such as water and alcohol solvents. The scope of the transformation was evaluated and a detailed mechanistic study involving control experiments, experimental kinetic studies, and computational investigations led to new insights into how the oxidation takes place via an unusual anionic process

An empirical investigation of Network-Oriented Behaviors in Business-to-Business Markets

This study is concerned with the extent to which network-oriented behaviors directly and/or indirectly affect firm performance. It argues that a firm's interaction behaviors in relation to an embedded network structure are key mechanisms that facilitate the development of important organizational capabilities in dealing with business partners. Such network-oriented behaviors, which are aimed at affecting the position of a company in the network, are consequently important drivers of firm performance, rather than the network structure alone. We develop a conceptual model that captures network-oriented behaviors as a driving force of firm performance in relation to three other key organizational behaviors, i.e., customer-oriented, competitor-oriented and relationship-oriented behaviors. We test the hypothesized model using a dataset of 354 responses collected via an on-line questionnaire from UK managers, whose organizations operate in business-to-business markets in either the manufacturing or services sectors. This study provides four key findings. First, a firm's networkoriented behaviors positively affect the development of customer-oriented and competitor-oriented behaviors. Secondly, they also foster relationship coordination with its important business partners within the network. Thirdly, the effective management of the firm's portfolio of relationships is found to mediate the positive impact of network-oriented behaviors on firm profitability. Lastly, closeness to end-users amplifies the positive effect of network-oriented behaviors on relationship portfolio effectiveness