Sap Flow and Water Consumption of Captain Cook Tree [Cascabela thevetia (l.) Lippold].

A two-year field study documented the diurnal and nocturnal sap flow rates and water consumption of young (YCC), adult (ACC) and mature (MCC) Captain Cook trees [Cascabela thevetia (L.) Lippold] that were invading a riparian habitat in northern Queensland. For comparison, two native trees [black tea tree (Melaleuca bracteata F. Muell.) and Moreton Bay ash (Corymbia tessellaris (F.Muell.) K.D.Hill & L.A.S.Johnson)] growing in association with Captain Cook tree were also monitored. Sap flow measurements were grouped into eight timeframes per day (early morning, late morning, early afternoon, late afternoon, early night, late night, early dawn and late dawn). Significant interactions in sap flow rate occurred between plant types, timeframes, and months. The magnitude of sap flow rate was Moreton Bay ash (YCC,ACC) and black tea tree(MCC). Maximum sap flow rates tended to occur during early (1-3 pm) to mid-afternoon (4-6 pm) for all age groups of Captain Cook tree and the two native trees. Diurnal sap flow rates were significantly greater than nocturnal, and on a monthly basis sap flow rates were highest over the spring to autumn period (September-May) and lowest during winter (June–August). Significant differences in water consumption also occurred between species and months. Water consumption peak time varied between plant types with most plants peaking in January except for MCC and Moreton Bay ash trees for which peak water consumption occurred in June and July respectively. Water consumption was high across all seasons except winter. The magnitude of water consumption was Moreton Bay ash, black tea tree (YCC,ACC,MCC trees). Moreton Bay ash registered maximal monthly water consumption (4700 L) compared with minimal consumption by MCC trees (55 L). On average, Captain Cook trees used 99% and 72% less water than Moreton Bay ash and black tea trees respectively. The significantly lower water consumption by Captain Cook trees compared with Moreton Bay ash and black tea trees may be offset by high population densities. Results also suggest that knowledge of optimal sap flow timeframes may be advantageous in exploring optimal timing for application of control operations related to management of Captain Cook trees

Synthesis and Reactivity of Dihydrogen Diruthenium Complexes.

Having two open coordination sites on the diruthenium complex makes for the ability to be able to be more precise when interacting with other compound. The side-on bonding of the bis(dihydrogen) gives it unique characteristics as well as unique capabilities. The Oganotransition Metal Chemistry book says that the dihydrogen is bonded by the donation of electrons from the H-H sigma bond as well as the back donation of electron density through the transition metal.3 In the past, many groups have studies on a mononuclear Ruthenium compound similar to the one we are synthesizing (see figure one). Our goal was to find out these characteristics and capabilities of the dihydrogen diruthenium

Flying Drones Beyond Visual Line of Sight Using 4G LTE: Issues and Concerns

The purpose of this paper is to address the extent in which 4G LTE can be used for air traffic management of small Unmanned Air Vehicles (sUAVs) and the limitations and enhancements that may be necessary. We provide a brief overview of the communications aspects of the Unmanned Aerial System (UAS) Traffic Management Project followed by the evolving trends in air traffic management including beyond visual line of sight (BVLOS) operations concepts and current BVLOS operational systems. Issues and Concerns are addressed including the rapidly evolving global regulations and the resulting communications requirements as well LTE downlink and uplink interference at altitude and how that interference affects command and control reliability as well as application data capabilities and mobility performance

A ridgelet transform method for constraining tectonic models via abyssal-hill morphology

Abyssal-hill shape and orientation are related to the direction and spreading rate of paleo-spreading centers. Therefore analyzing abyssal-hill shape and trend is useful for constraining tectonic models of regions devoid of magnetic reversal anomalies. Detecting systematic changes of abyssal-hill shapes or trends, due to changes in spreading rate or direction, is not straightforward, which makes it difficult to determine appropriate regions over which to average abyssal-hill parameters. Often, however, detecting these systematic changes, where they occur, and the scale over which they occur, is of primary importance for tectonic reconstructions. We present a new method of abyssal-hill analysis that is based on the ridgelet transform, a relative of the two-dimensional wavelet transform. Our method is capable of locally estimating the width, azimuth, and root-mean-square (RMS) amplitude of abyssal-hill fabric and highlights changes in these parameters across a survey area, making it possible to identify regions created with a constant spreading rate and direction. We use three multibeam swaths, one crossing the Osbourn Trough in the southwest Pacific Basin, one crossing the East Pacific Rise, and one crossing the Mid-Atlantic Ridge, to demonstrate the utility and performance of our method

Acupuncture is a feasible treatment for post-thoracotomy pain: results of a prospective pilot trial

BACKGROUND: Thoracotomy is associated with severe pain that may persist for years. Acupuncture is a complementary therapy with a proven role in pain control. A randomized trial showed that acupuncture was effective in controlling pain after abdominal surgery, but the efficacy of this technique for the treatment of thoracotomy pain has not been established. We developed a novel technique for convenient application of acupuncture to patients undergoing thoracotomy, and in a Phase II trial evaluated the safety of this intervention and the feasibility of doing a randomized trial. METHODS: Adult patients scheduled for unilateral thoracotomy with preoperative epidural catheter placement received acupuncture immediately prior to surgery. Eighteen semi-permanent intradermal needles were inserted on either side of the spine, and four were inserted in the legs and auricles. Needles were removed after four weeks. Using a numerical rating scale, pain was measured on the first five postoperative days. After discharge, pain was assessed using the Brief Pain Inventory at 7, 30, 60 and 90 days. RESULTS: Thirty-six patients were treated with acupuncture. Of these, 25, 23, and 22 patients provided data at 30, 60, and 90 days, respectively. The intervention was well tolerated by patients with only one minor and transient adverse event of skin ulceration. CONCLUSION: The rate of data completion met our predefined criterion for determining a randomized trial to be feasible (at least 75% of patients tolerated the intervention and provided evaluable data). This novel intervention is acceptable to patients undergoing thoracotomy and does not interfere with standard preoperative care. There was no evidence of important adverse events. We are now testing the hypothesis that acupuncture significantly adds to standard perioperative pain management in a randomized trial

Phased Array Antenna for the Mitigation of UAS Interference

The growing demand for Unmanned Aerial Systems (UAS) operating beyond the line of sight (BLOS) has resulted in an increased interest in using existing commercial satellite communication capabilities for UAS command and control (C2) communications. The World Radiocommunication Conference in 2015 designated portions of Ku-Band and Ka-Band fixed satellite service (FSS) spectrum to support UAS C2 communications, provided that potential interference with existing co-allocated users in these bands is addressed. As the user base in this new spectrum allocation expands, there is an increased potential for interference with existing terrestrial communication systems operating under fixed service (FS) allocations. The portion of Ka-Band spectrum allocated for UAS C2 avoids significant interference issues, but the Ku-Band allocation contains a co-primary FS allocation, creating potential interference problems. Therefore, UAS must identify solutions to avoid interfering with these existing FS ground sites while maintaining good links with satellite constellations. UAS operating with conventional fixed feed parabolic antennas will have difficulty in meeting interference thresholds, especially at high latitudes where the antennas will operate with low elevation angles. As a means of addressing this limitation, NASA is investigating the use of a phased array antenna to enable mitigation of interference into ground-based FS receivers. In this paper, a novel lightweight conformal phased array antenna will be presented that can use null-steering and/or beam shaping to avoid ground interference while simultaneously providing strong satellite microwave links for communications. The reduced weight of this design and ability to integrate into the fuselage of smaller UAS platforms will also be discussed as a potential solution to provide BLOS operation via spectrum sharing for an expanding user base. This paper will review design aspects of the conformal phased array antenna, describe the intended benefits in reducing interference with FS ground stations, and describe phased array development and test plans

Assessing C2 Communications for UAS Traffic Management

The National Aeronautics and Space Administration's (NASA) Unmanned Aircraft Systems (UAS) Traffic Management (UTM) project works to develop tools and technologies essential for safely enabling civilian low-altitude UAS operations. Currently there is no established infrastructure to enable and safely manage the widespread use of low-altitude airspace and UAS operations, regardless of the type of UAS. The UTM technical challenge will develop comprehensive and validated airspace operations and integration requirements to safely enable large-scale persistent access to visual line of sight and autonomous beyond visual line of sight small UAS in low-altitude airspace. Within the UTM project, a number of communications technologies to support UTM command and control (C2) are under investigation. In particular, commercial networked cellular systems are being tested and assessed for their ability to meet the reliability, scalability, cybersecurity and redundancy required. NASA Glenn Research Center is studying some of the aspects of employing such networks for UTM C2 communications. This includes the development of a test platform for sensing and characterizing the airborne C2 communications environment at various altitudes and in various terrains and topologies, measuring such aspects as received signal strength and interference. System performance aspects such as latency in the link, handover performance, packet error loss rate, drop outs, coverage gaps and other aspects impacting UTM operation will also be assessed. In this paper we explore some of the C2 approaches being proposed and demonstrated in the UTM project, the reliability, availability and other general C2 performance requirements, and approaches to evaluating and analyzing UTM C2 links based on commercial cellular networks

ADS-B Mixed sUAS and NAS System Capacity Analysis and DAA Performance

Automatic Dependent Surveillance-Broadcast (ADS-B) technology was introduced more than twenty years ago to improve surveillance within the US National Airspace Space (NAS) as well as in many other countries. Via the NextGen initiative, implementation of ADS-B technology across the US is planned in stages between 2012 and 2025. ADS-B's automatic one second epoch packet transmission exploits on-board GPS-derived navigational information to provide position information, as well as other information including vehicle identification, ground speed, vertical rate and track angle. The purpose of this technology is to improve surveillance data accuracy and provide access to better situational awareness to enable operational benefits such as shorter routes, reduced flight time and fuel burn, and reduced traffic delays, and to allow air traffic controllers to manage aircraft with greater safety margins. Other than the limited amount of information bits per packet that can be sent, ADS-B's other hard-limit limitation is capacity. Small unmanned aircraft systems (sUAS) can utilize limited ADS-B transmission power, in general, thus allowing this technology to be considered for use within a combined NAS and sUAS environment, but the potential number and density of sUAS predicted for future deployment calls into question the ability of ADS-B systems to meet the resulting capacity requirement. Hence, studies to understand potential limitations of ADS-B to fulfill capacity requirements in various sUAS scenarios are of great interest. In this paper we, validate/improve on, previous work performed by the MITRE Corporation concerning sUAS power and capacity in a sUAS and General Aviation (GA) mixed environment. In addition, we implement its inherent media access control layer capacity limitations which was not shown in the MITRE paper. Finally, a simple detect and avoid (DAA) algorithm is implemented to display that ADS-B technology is a viable technology for a mixed NAS/sUAS environment even in proposed larger mixed density environments