Sample records for technetates
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Status of Seal Development at Technetics
NASA Astrophysics Data System (ADS)
Chappel, Doug
2002-10-01
Technetics has recently reported results for blade tip seal rub characteristics. Expanding on this work, Technetics will share rub characteristics for knife edge abradable seal systems typical of those found at vane inner air seal and shaft seal locations.
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Agile Objects: Component-Based Inherent Survivability
2003-12-01
pages 37-55, February 1990. [3] Clar, David D., Van Jacobson, John Romkey, and Howard Salwen. “An analysis of TCP processing overhead”. IEEE...www.microsoft.com/technet/treeview/default.asp?url=/technet/prodtech nol/acs/Default.asp 34. Chaum , D.L., Untraceable Electronic Mail, Return
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75 FR 66411 - Data Collection Available for Public Comments and Recommendations
Federal Register 2010, 2011, 2012, 2013, 2014
2010-10-28
... INFORMATION CONTACT: George Solomon, Office of Senior Policy, 202-205-7343 [email protected] Curtis B. Rich.... Title: ``Small Business Innovation Research (SBIR) and Small Business Technology (STTR) Tech-Net...
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Talking Transition--An Interview with an Expert
ERIC Educational Resources Information Center
Greathouse, Dan; Shaughnessy, Michael F.
2010-01-01
Ginger Blalock is an educational consultant in the area of career development and transition for youth with special needs, currently serving as facilitator for the NMPED-funded Transition Outcomes Project and Statewide Transition Coordinating Council, educational consultant for Technet's administration of the NMDWS WIRED Project (Workforce…
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Ceramic TBS/porous metal compliant layer
NASA Technical Reports Server (NTRS)
Tolokan, Robert P.; Jarrabet, G. P.
1992-01-01
Technetics Corporation manufactures metal fiber materials and components used in aerospace applications. Our technology base is fiber metal porous sheet material made from sinter bonded metal fibers. Fiber metals have percent densities (metal content by volume) from 10 to 65 percent. Various topics are covered and include the following: fiber metal materials, compliant layer thermal bayer coatings (TBC's), pad properties, ceramic/pad TBC design, thermal shock rig, fabrication, and applications.
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Advancing MEMS Technology Usage through the MUMPS (Multi-User MEMS Processes) Program
NASA Technical Reports Server (NTRS)
Koester, D. A.; Markus, K. W.; Dhuler, V.; Mahadevan, R.; Cowen, A.
1995-01-01
In order to help provide access to advanced micro-electro-mechanical systems (MEMS) technologies and lower the barriers for both industry and academia, the Microelectronic Center of North Carolina (MCNC) and ARPA have developed a program which provides users with access to both MEMS processes and advanced electronic integration techniques. The four distinct aspects of this program, the multi-user MEMS processes (MUMP's), the consolidated micro-mechanical element library, smart MEMS, and the MEMS technology network are described in this paper. MUMP's is an ARPA-supported program created to provide inexpensive access to MEMS technology in a multi-user environment. It is both a proof-of-concept and educational tool that aids in the development of MEMS in the domestic community. MUMP's technologies currently include a 3-layer poly-silicon surface micromachining process and LIGA (lithography, electroforming, and injection molding) processes that provide reasonable design flexibility within set guidelines. The consolidated micromechanical element library (CaMEL) is a library of active and passive MEMS structures that can be downloaded by the MEMS community via the internet. Smart MEMS is the development of advanced electronics integration techniques for MEMS through the application of flip chip technology. The MEMS technology network (TechNet) is a menu of standard substrates and MEMS fabrication processes that can be purchased and combined to create unique process flows. TechNet provides the MEMS community greater flexibility and enhanced technology accessibility.
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Overview of NASA Glenn Seal Developments
NASA Technical Reports Server (NTRS)
Steinetz, Bruce M.; Proctor, Margaret P.; Dunlap, Patrick H., Jr.; Delgado, Irebert; DeMange, Jeffrey J.; Daniels, Christopher C.; Lattime, Scott B.
2004-01-01
Turbine engine studies have shown that reducing high pressure turbine (HPT) blade tip clearances will reduce fuel burn, lower emissions, retain exhaust gas temperature margin and increase range. Dr. Lattime presented the design and development status of a new Active Clearance Control Test rig aimed at demonstrating advanced ACC approaches and sensors. Mr. Melcher presented controls considerations for turbine active clearance control. Mr. Geisheimer of Radatech presented an overview of their microwave blade tip sensor technology. Microwave tip sensors show promise of operation in the extreme gas temperatures present in the HPT location. Mr. Justak presented an overview of non-contacting seal developments at Advanced Technologies Group. Dr. Braun presented investigations into a non-contacting finger seal under development by NASA GRC and University of Akron. Dr. Stango presented analytical assessments of the effects of flow-induced radial loads on brush seal behavior. Mr. Flaherty presented innovative seal and seal fabrication developments at FlowServ. Mr. Chappel presented abradable seal developments at Technetics. Dr. Daniels presented an overview of NASA GRC s acoustic seal developments. NASA is investigating the ability to harness high amplitude acoustic waves, possible through a new field of acoustics called Resonant Macrosonic Synthesis, to effect a non-contacting, low leakage seal. Dr. Daniels presented early results showing the ability to restrict flow via acoustic pressures. Dr. Athavale presented numerical results simulating the flow blocking capability of a pre-prototype acoustic seal.
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Brown, Elizabeth; Devereux, Sara; Fairhead, Cassandra; Holeman, Isaac
2017-01-01
Background The benefits of vaccination have been comprehensively proven; however, disparities in coverage persist because of poor health system management, limited resources, and parental knowledge and attitudes. Evidence suggests that health interventions that engage local parties in communication strategies improve vaccination uptake. As mobile technology is widely used to improve health communication, mobile health (mHealth) interventions might be used to increase coverage. Objective The aim of this study was to conduct a systematic review of the available literature on the use of mHealth to improve vaccination in low- and middle-income countries with large numbers of unvaccinated children. Methods In February 2017, MEDLINE (Medical Literature Analysis and Retrieval System Online), Scopus, and Web of Science, as well as three health organization websites—Communication Initiative Network, TechNet-21, and PATH—were searched to identify mHealth intervention studies on vaccination uptake in 21 countries. Results Ten peer-reviewed studies and 11 studies from white or gray literature were included. Nine took place in India, three in Pakistan, two each in Malawi and Nigeria, and one each in Bangladesh, Zambia, Zimbabwe, and Kenya. Ten peer-reviewed studies and 7 white or gray studies demonstrated improved vaccination uptake after interventions, including appointment reminders, mobile phone apps, and prerecorded messages. Conclusions Although the potential for mHealth interventions to improve vaccination coverage seems clear, the evidence for such interventions is not. The dearth of studies in countries facing the greatest barriers to immunization impedes the prospects for evidence-based policy and practice in these settings. PMID:28978495
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Oliver-Williams, Clare; Brown, Elizabeth; Devereux, Sara; Fairhead, Cassandra; Holeman, Isaac
2017-10-04
The benefits of vaccination have been comprehensively proven; however, disparities in coverage persist because of poor health system management, limited resources, and parental knowledge and attitudes. Evidence suggests that health interventions that engage local parties in communication strategies improve vaccination uptake. As mobile technology is widely used to improve health communication, mobile health (mHealth) interventions might be used to increase coverage. The aim of this study was to conduct a systematic review of the available literature on the use of mHealth to improve vaccination in low- and middle-income countries with large numbers of unvaccinated children. In February 2017, MEDLINE (Medical Literature Analysis and Retrieval System Online), Scopus, and Web of Science, as well as three health organization websites-Communication Initiative Network, TechNet-21, and PATH-were searched to identify mHealth intervention studies on vaccination uptake in 21 countries. Ten peer-reviewed studies and 11 studies from white or gray literature were included. Nine took place in India, three in Pakistan, two each in Malawi and Nigeria, and one each in Bangladesh, Zambia, Zimbabwe, and Kenya. Ten peer-reviewed studies and 7 white or gray studies demonstrated improved vaccination uptake after interventions, including appointment reminders, mobile phone apps, and prerecorded messages. Although the potential for mHealth interventions to improve vaccination coverage seems clear, the evidence for such interventions is not. The dearth of studies in countries facing the greatest barriers to immunization impedes the prospects for evidence-based policy and practice in these settings. ©Clare Oliver-Williams, Elizabeth Brown, Sara Devereux, Cassandra Fairhead, Isaac Holeman. Originally published in JMIR Mhealth and Uhealth (http://mhealth.jmir.org), 04.10.2017.
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Weaver, Jamie; Soderquist, Chuck; Gassman, Paul
The local chemistry of technetium-99 ( 99Tc) in oxide glasses is important for understanding the incorporation and long-term release of Tc from nuclear waste glasses, both those for legacy defense wastes and fuel reprocessing wastes. Tc preferably forms Tc(VII), Tc(IV), or Tc(0) in glass, depending on the level of reduction of the melt. Tc(VII) in oxide glasses is normally assumed to be isolated pertechnetate TcO 4 -anions surrounded by alkali, but can occasionally precipitate as alkali pertechnetate salts such as KTcO 4and NaTcO 4when Tc concentration is high. In these cases, Tc(VII) is 4-coordinated by oxygen. A reinvestigation of themore » chemistry of alkali-technetium-oxides formed under oxidizing conditions and at temperatures used to prepare nuclear waste glasses showed that higher coordinated alkali Tc(VII) oxide species had been reported, including those with the TcO 5 -and TcO 6 -anions. The chemistry of alkali Tc(VII) and other alkali-Tc-oxides is reviewed, along with relevant synthesis conditions. Additionally, we report attempts to make 5- and 6-coordinate pertechnetate compounds of K, Na, and Li, i.e. TcO 5 -and TcO 6 -. It was found that higher coordinated species are very sensitive to water, and easily decompose into their respective pertechnetates. It was difficult to obtain pure compounds, but mixtures of the pertechnetate and other phase(s) were frequently found, as evidenced by x-ray absorption spectroscopy (XAS), neutron diffraction (ND), and Raman spectroscopy. Low temperature electron paramagnetic resonance (EPR) measurements showed the possibility of Tc(IV) and Tc(VI) in Na 3TcO 5and Na 5TcO 6compounds. It was hypothesized that the smaller counter cation would result in more stable pertechnetates. To confirm the synthesis method, LiReO 4and Li 5ReO 6were prepared, and their Raman spectra match those in the literature. Subsequently, the Tc versions LiTcO 4and Li 5TcO 6were synthesized and characterized by ND, Raman spectroscopy, XANES, and EXAFS. The Li 5TcO 6was a marginally stable compound that appears to have the same structure as that known for Li 5ReO 6. Implications of the experimental work on stability of alkali technetate compounds and possible role in the volatilization of Tc are discussed.« less
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Synthesis and Characterization of 5- and 6- Coordinated Alkali Pertechnetates
DOE Office of Scientific and Technical Information (OSTI.GOV)
Weaver, Jamie; Soderquist, Chuck; Gassman, Paul
ABSTRACT The local chemistry of technetium-99 ( 99Tc) in oxide glasses is important for understanding the incorporation and long-term release of Tc from nuclear waste glasses, both those for legacy defense wastes and fuel reprocessing wastes. Tc preferably forms Tc(VII), Tc(IV), or Tc(0) in glass, depending on the level of reduction of the melt. Tc(VII) in oxide glasses is normally assumed to be isolated pertechnetate TcO 4 -anions surrounded by alkali, but can occasionally precipitate as alkali pertechnetate salts such as KTcO 4and NaTcO 4when Tc concentration is high. In these cases, Tc(VII) is 4-coordinated by oxygen. A reinvestigation ofmore » the chemistry of alkali-technetium-oxides formed under oxidizing conditions and at temperatures used to prepare nuclear waste glasses showed that higher coordinated alkali Tc(VII) oxide species had been reported, including those with the TcO 5 -and TcO 6 -anions. The chemistry of alkali Tc(VII) and other alkali-Tc-oxides is reviewed, along with relevant synthesis conditions. Additionally, we report attempts to make 5- and 6-coordinate pertechnetate compounds of K, Na, and Li, i.e. TcO 5 -and TcO 6 -. It was found that higher coordinated species are very sensitive to water, and easily decompose into their respective pertechnetates. It was difficult to obtain pure compounds, but mixtures of the pertechnetate and other phase(s) were frequently found, as evidenced by x-ray absorption spectroscopy (XAS), neutron diffraction (ND), and Raman spectroscopy. Low temperature electron paramagnetic resonance (EPR) measurements showed the possibility of Tc(IV) and Tc(VI) in Na 3TcO 5and Na 5TcO 6compounds. It was hypothesized that the smaller counter cation would result in more stable pertechnetates. To confirm the synthesis method, LiReO 4and Li 5ReO 6were prepared, and their Raman spectra match those in the literature. Subsequently, the Tc versions LiTcO 4and Li 5TcO 6were synthesized and characterized by ND, Raman spectroscopy, XANES, and EXAFS. The Li 5TcO 6was a marginally stable compound that appears to have the same structure as that known for Li 5ReO 6. Implications of the experimental work on stability of alkali technetate compounds and possible role in the volatilization of Tc are discussed.« less
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Peştean, Claudiu; Bărbuş, Elena; Piciu, Andra; Larg, Maria Iulia; Sabo, Alexandrina; Moisescu-Goia, Cristina; Piciu, Doina
2016-01-01
Melanoma is a disease that has an increasing incidence worldwide. Sentinel lymph node scintigraphy is a diagnostic tool that offers important information regarding the localization of the sentinel lymph nodes offering important input data to establish a pertinent and personalized therapeutic strategy. The golden standard in body contouring for sentinel lymph node scintigraphy is to use a planar flood source of Cobalt-57 (Co-57) placed behind the patients, against the gamma camera. The purpose of the study was to determine the performance of the procedure using a flood calibration planar phantom filled with aqueous solution of Technetion-99m (Tc-99m) in comparison with the published data in literature where the gold standard was used. The study was conducted in the Department of Nuclear Medicine of Oncology Institute "Prof. Dr. Ion Chiricuţă" Cluj-Napoca in 95 patients, 31 males and 64 females. The localization of the lesions was grouped by anatomical regions as follows: 23 on lower limbs, 17 on upper limbs, 45 on thorax and 10 on abdomen. The calibration flood phantom containing aqueous solution of Tc-99m pertechnetate was used as planar source to visualize the body contour of the patients for a proper anatomic localization of detected sentinel lymph nodes. The radiopharmaceutical uptake in sentinel lymph nodes has been recorded in serial images following peritumoral injection of 1 ml solution of Tc-99m albumin nanocolloids with an activity of 1 mCi (37 MBq). The used protocol consisted in early acquired planar images within 15 minutes post-injection and delayed images at 2-3 hours and when necessary, additional images at 6-7 hours. The acquisition matrix used was 128×128 pixels for an acquisition time of 5 - 7 minutes. The skin projection of the sentinel lymph nodes was marked on the skin and surgical removal of detected sentinel lymph nodes was performed the next day using a gamma probe for detection and measurements. The sentinel lymph nodes were detected in 92 cases and confirmed with the gamma probe during the surgical procedure. The localization of the lymph nodes was as follows: for the tumors localized on lower limb 23 lymph nodes were localized in inguinal region, for the tumors localized on upper limb, 17 lymph nodes were localized in axilla, for the tumors localized on the thorax, 40 lymph nodes were localized in axilla and 3 were localized in the inguinal region; for the tumors localized on the abdomen, 1 lymph node was localized in axilla and 8 lymph nodes was localized in inguinal region. Regarding the negative sentinel lymph node cases, 2 cases were registered for primarily lesions localized on thorax and 1 for a lesion localized on abdomen. According to histology, 26 cases revealed lymphatic metastatic invasion. Dose rates measured at 1m from the calibrator phantom had an average value of 3.46 μSv/h (SD 0.19) and at 1.4m, the value was 2.57 μSv/h (SD 0.22). Dose rates measured at the same distances from the Co-57 planar flood source had a average values of 32.5μSv/h (SD 0.11) respectively 24.1 μSv/h (SD 0.14). The planar calibration flood phantom is an effective tool for body contouring in sentinel lymph node scintigraphy and offers accurate anatomical information to efficiently localize the detected sentinel lymph nodes in melanoma, being for the first time used and mentioned as a pertinent alternative in our department.