Fabrication and test of a space power boiler feed electromagnetic pump. Part 1: Design and manufacture of pump

A three-phase helical induction electromagnetic (EM) pump has been designed and built. This pump was designed for use as the boiler-feed pump of a potassium Rankine-cycle space electric power system. The pump is constructed of high temperature materials including a T-111 duct, Hiperco 27 magnetic material, nickel clad silver conductor wire, and a completely inorganic insulation system. The pump is designed to deliver 3.25 lb/sec potassium at 1000 F with a developed head of 240 psi while being cooled by 800 F NaK. At these conditions, the overall pump efficiency is expected to be 18%

STS-99 Shuttle Radar Topography Mission Stability and Control

The Shuttle Radar Topography Mission (SRTM) flew aboard Space Shuttle Endeavor February 2000 and used interferometry to map 80% of the Earth's landmass. SRTM employed a 200-foot deployable mast structure to extend a second antenna away from the main antenna located in the Shuttle payload bay. Mapping requirements demanded precision pointing and orbital trajectories from the Shuttle on-orbit Flight Control System (PCS). Mast structural dynamics interaction with the FCS impacted stability and performance of the autopilot for attitude maneuvers and pointing during mapping operations. A damper system added to ensure that mast tip motion remained with in the limits of the outboard antenna tracking system while mapping also helped to mitigate structural dynamic interaction with the FCS autopilot. Late changes made to the payload damper system, which actually failed on-orbit, required a redesign and verification of the FCS autopilot filtering schemes necessary to ensure rotational control stability. In-flight measurements using three sensors were used to validate models and gauge the accuracy and robustness of the pre-mission notch filter design

Selection of microorganisms degrading S-Metolachlor herbicide.

The aim of this work was to study herbicide degradation through selected microorganisms from humus and soil subjected to different plantation systems. The following bacterial species were identified: Klebsiella pneumoniae pneumoniae GC s.B strain 1, Pseudomonas alcaligenes, Enterobacter aerogenes GC s.A and Klebsiella pneumoniae pneumoniae GC s.B strain 2. Growth studies yet suggested the possibility of a very long lag phase. Although, culture with the herbicide presented biofilm formation and there were color changes in the herbicide that could have interfered with the espectrophotometry readings. After 5 days of incubation at 35ºC, the difference in the concentration of herbicide was 14.42% on average and after 10 days, 35.01%

CoRiMaS—An Ontological Approach to Cooperative Risk Management in Seaports

For today’s global value chains, seaports and their operations are indispensable components. In many cases, the cargo handling takes place in close proximity to residential and/or environmentally sensitive areas. Furthermore, seaports are often not operated by a single organization, but need to be considered as communities of sometimes hundreds of internal and external stakeholders. Due to their close cooperation in the cargo handling process, risk management should be a common approach among the internal stakeholders as well in order to effectively mitigate and respond to emerging risks. However, empirical research has revealed that risk management is often limited to the organization itself, which indicates a clear lack of cooperation. Primary reasons in this regard are missing knowledge about the relations and responsibilities within the port and differing terminologies. Therefore, we propose an ontology (CoRiMaS) that implements a developed reference model for risk management that explicitly aims at seaports with a cooperative approach to risk management. CoRiMaS has been designed looking at the Semantic Web and at the Linked Data model to provide a common interoperable vocabulary in the target domain. The key concepts of our ontology comprise the hazard, stakeholder, seaport, cooperation aspect, and risk management process. We validated our ontology by applying it in a case study format to the Port of Hamburg (Germany). The CoRiMaS ontology can be widely applied to foster cooperation within and among seaports. We believe that such an ontological approach has the potential to improve current risk management practices and, thereby, to increase the resilience of operations, as well as the protection of sensitive surrounding areas.</jats:p

The Impact of New Technologies on Learning: A Literature review on Mobile Collaborative Learning

Mobile Collaborative Learning (MCL) has recently caught the attention of the research community because of its potential impact on improving learners\u27 effectiveness and performance. Nevertheless, to be really effective, the potential of MCL-based solutions is still largely unexplored, as well as further research is needed to develop improved learning environments. This literature review aims to discuss the possible impact of MCL, looking at a number of typical parameters, such as user satisfaction, perceived ease-of-use, perceived usefulness, impact on the affective and cognitive domain, and perceived enjoyment. The literature review has pointed out that, by adopting the MCL approach, learners improve their motivation, as well as their cognitive skills. It points out a positive impact also at an affective level. Additionally, we found that MCL currently targets education at any level, including university and school level. Last but not least, it seems to positively affect also learning outcomes, namely learners’ performance. On the negative side, the study found a lack of research attention on possible difficulties, constraints, and barriers. Finally, learning environments are expected to become more and more sophisticated in the next future (e.g. by using augmented reality), and mobile technology is expected to play an even more relevant rol

Implant-Prosthetic rehabilitation in bilateral agenesis of maxillary lateral incisors with a mini split crest

The reported clinical case describes the surgical procedure of ridge augmentation by using a "split crest" technique with a partial thickness flap and a subsequent implant-prosthetic rehabilitation aimed at treating a bilateral agenesis of the upper lateral incisors. In such cases with vestibule-palatal and mesial-distal scarce bone thicknesses associated with the need of a proper functional and aesthetic rehabilitation, the split crest technique is particularly suitable. In the case we reported, because of the poor bone thicknesses, we performed a minimally invasive split crest which allowed a correct insertion of the fixtures. This technique allowed us to achieve an optimal functional and aesthetic rehabilitation; moreover, we obtained a good emergency profile, ensuring the vitality of the close teeth and ensuring a good primary stability and the following osseointegration of dental implants

Minimally Invasive Stent Screw-Assisted Internal Fixation Technique Corrects Kyphosis in Osteoporotic Vertebral Fractures with Severe Collapse: A Pilot "Vertebra Plana" Series.

BACKGROUND AND PURPOSE Fractures with "vertebra plana" morphology are characterized by severe vertebral body collapse and segmental kyphosis; there is no established treatment standard for these fractures. Vertebroplasty and balloon kyphoplasty might represent an undertreatment, but surgical stabilization is challenging in an often elderly osteoporotic population. This study assessed the feasibility, clinical outcome, and radiologic outcome of the stent screw-assisted internal fixation technique using a percutaneous implant of vertebral body stents and cement-augmented pedicle screws in patients with non-neoplastic vertebra plana fractures. MATERIALS AND METHODS Thirty-seven consecutive patients with vertebra plana fractures were treated with the stent screw-assisted internal fixation technique. Vertebral body height, local and vertebral kyphotic angles, outcome scales (numeric rating scale and the Patient's Global Impression of Change), and complications were assessed. Imaging and clinical follow-up were obtained at 1 and 6 months postprocedure. RESULTS Median vertebral body height restoration was 7 mm (+74%), 9 mm (+150%), and 3 mm (+17%) at the anterior wall, middle body, and posterior wall, respectively. Median local and vertebral kyphotic angles correction was 8° and 10° and was maintained through the 6-month follow-up. The median numeric rating scale score improved from 8/10 preprocedure to 3/10 at 1 and 6 months (P < .001). No procedural complications occurred. CONCLUSIONS The stent screw-assisted internal fixation technique was effective in obtaining height restoration, kyphosis correction, and pain relief in patients with severe vertebral collapse