Design, Construction, and Performance of New-generation Open-graded Friction Courses
DOT National Transportation Integrated Search
2000-04-01
Open-graded friction course (OGFC) has been used by several state departments of transportation (DOT) since 1950. While many DOTs report good performance, many other states stopped using OGFC due to unacceptable performance and/or lack of adequate du...
Design of New-Generation Open-Graded Friction Courses (Revised)
DOT National Transportation Integrated Search
1999-12-01
Open-graded friction course (OGFC) has been used by several state departments of transportation (DOT) since 1950. While many DOTs report good performance, many other states stopped using OGFC due to unacceptable performance and/or lack of adequate du...
Anxiety and Academic Reading Performance among Malay ESL Learners
ERIC Educational Resources Information Center
Mohd. Zin, Zuhana; Rafik-Galea, Shameem
2010-01-01
Research into the factors that contribute to reading performance decrement in L2 reading among ESL university students is still being extensively researched in the context of ELT. This is because successful academic performance is highly dependent on good reading ability. While it is widely accepted that poor reading performance is due to lack of…
Fate of iprovalicarb, indoxacarb, and boscalid residues in grapes and wine by GC-ITMS analysis.
Angioni, Alberto; Dedola, Fabrizio; Garau, Vincenzo Luigi; Schirra, Mario; Caboni, Pierluigi
2011-06-22
The behavior in field and the transfer from grapes to wine during winemaking of iprovalicarb, indoxacarb, and boscalid was studied. The residue levels found in grapes were far below the MRLs set for grapes in EU, accounting at harvest time 0.81, 0.43, and 4.23 mg/kg for iprovalicarb, indoxacarb, and boscalid, respectively. The residue levels in the samples treated with boscalid may have residual problems (due to an accumulation effect) if repeated field treatments will be performed. Winemaking experiments showed a complete transfer of all pesticide from grapes to the must, while in wine the residues were low or negligible due to the adsorbing effect of lees and pomace. The clarification experiments showed a good removal of pesticide residues from the wine media, for all pesticides. The GC-ITMS method showed good performance with adequate recoveries ranging from 75 to 115%, and good method limits of quantitation (LOQs) and of determination (LODs) far below MRLs.
Optical Fiber Grating Hydrogen Sensors: A Review
Dai, Jixiang; Zhu, Li; Wang, Gaopeng; Xiang, Feng; Qin, Yuhuan; Wang, Min; Yang, Minghong
2017-01-01
In terms of hydrogen sensing and detection, optical fiber hydrogen sensors have been a research issue due to their intrinsic safety and good anti-electromagnetic interference. Among these sensors, hydrogen sensors consisting of fiber grating coated with sensitive materials have attracted intensive research interests due to their good reliability and distributed measurements. This review paper mainly focuses on optical fiber hydrogen sensors associated with fiber gratings and various materials. Their configurations and sensing performances proposed by different groups worldwide are reviewed, compared and discussed in this paper. Meanwhile, the challenges for fiber grating hydrogen sensors are also addressed. PMID:28287499
Optical Fiber Grating Hydrogen Sensors: A Review.
Dai, Jixiang; Zhu, Li; Wang, Gaopeng; Xiang, Feng; Qin, Yuhuan; Wang, Min; Yang, Minghong
2017-03-12
In terms of hydrogen sensing and detection, optical fiber hydrogen sensors have been a research issue due to their intrinsic safety and good anti-electromagnetic interference. Among these sensors, hydrogen sensors consisting of fiber grating coated with sensitive materials have attracted intensive research interests due to their good reliability and distributed measurements. This review paper mainly focuses on optical fiber hydrogen sensors associated with fiber gratings and various materials. Their configurations and sensing performances proposed by different groups worldwide are reviewed, compared and discussed in this paper. Meanwhile, the challenges for fiber grating hydrogen sensors are also addressed.
Bounds on Block Error Probability for Multilevel Concatenated Codes
NASA Technical Reports Server (NTRS)
Lin, Shu; Moorthy, Hari T.; Stojanovic, Diana
1996-01-01
Maximum likelihood decoding of long block codes is not feasable due to large complexity. Some classes of codes are shown to be decomposable into multilevel concatenated codes (MLCC). For these codes, multistage decoding provides good trade-off between performance and complexity. In this paper, we derive an upper bound on the probability of block error for MLCC. We use this bound to evaluate difference in performance for different decompositions of some codes. Examples given show that a significant reduction in complexity can be achieved when increasing number of stages of decoding. Resulting performance degradation varies for different decompositions. A guideline is given for finding good m-level decompositions.
[Good governance of publicly-produced health services: ideas for moving forward].
Freire, José Manuel; Repullo, Jose Ramon
2011-06-01
The good performance of publicly-produced health services is of vital importance, well beyond the health sector. Taking into account the great complexity of the health services in the public sector due both to their public and professional nature, we identify seven Gordian Knots as being responsible for the most frequent problems of publicly produced health services in Spain and Latin America. From the concept of good governance we take its character as a normative and ethical benchmark and its potential to renew and invigorate the government of the public sector. From comparative analysis of publicly-produced health services in the best performing countries, we extract eight characteristics which contribute significantly to good performance. A final reflection is on the relevance of the importance of offsetting the potential hostility to a reformist impulse of the status-quo with alliances that strengthen public trust and the social contract between health professionals and citizens based on the values of public health systems.
Novel Nanofiber-based Membrane Separators for Lithium-Ion Batteries
NASA Astrophysics Data System (ADS)
Yanilmaz, Meltem
Lithium-ion batteries have been widely used in electronic devices including mobile phones, laptop computers, and cameras due to their high specific energy, high energy density, long cycling lifetime, and low self-discharge rate. Nowadays, lithium-ion batteries are finding new applications in electric/hybrid vehicles and energy storage for smart grids. To be used in these new applications, novel battery components are needed so that lithiumion batteries with higher cell performance, better safety, and lower cost can be developed. A separator is an important component to obtain safe batteries and its primary function is to prevent electronic contact between electrodes while regulating cell kinetics and ionic flow. Currently, microporous membranes are the most commonly used separator type and they have good mechanical properties and chemical stability. However, their wettability and thermal stabilities are not sufficient for applications that require high operating temperature and high performance. Due to the superior properties such as large specific surface area, small pore size and high porosity, electrospun nanofiber membranes can be good separator candidate for highperformance lithium-ion batteries. In this work, we focus our research on fabricating nanofiber-based membranes to design new high-performance separators with good thermal stability, as well as superior electrochemical performance compared to microporous polyolefin membranes. To combine the good mechanical strength of PP nonwovens with the excellent electrochemical properties of SiO2/polyvinylidene fluoride (PVDF) composite nanofibers, SiO 2/PVDF composite nanofiber-coated PP nonwoven membranes were prepared. It was found that the addition of SiO2 nanoparticles played an important role in improving the overall performance of these nanofiber-coated nonwoven membranes. Although ceramic/polymer composites can be prepared by encapsulating ceramic particles directly into polymer nanofibers, the performance of the resultant composite membranes is restricted because these nanoparticles are not exposed to liquid electrolytes and have limited effect on improving the cell performance. Hence, we introduced new nanoparticle-on-nanofiber hybrid membrane separators by combining electrospraying with electrospinning techniques. Electrochemical properties were enhanced due to the increased surface area caused by the unique hybrid structure of SiO2 nanoparticles and PVDF nanofibers. To design a high-performance separator with enhanced mechanical properties and good thermal stability, electrospun SiO2/nylon 6,6 nanofiber membranes were fabricated. It was found that SiO2/nylon 6,6 nanofiber membranes had superior thermal stability and mechanical strength. Electrospinning has serious drawbacks such as low spinning rate and high production cost. Centrifugal spinning is a fast, cost-effective and safe alternative to the electrospinning. SiO2/polyacrylonitrile (PAN) membranes were produced by using centrifugal spinning. Compared with commercial microporous polyolefin membranes, SiO2/PAN membranes had larger liquid electrolyte uptake, higher electrochemical oxidation limit, and lower interfacial resistance with lithium. SiO2/PAN membrane separators were assembled into lithium/lithium iron phosphate cells and these cells exhibited good cycling and C-rate performance.
Li, Zhenzhen; Xin, Yanmei; Zhang, Zhonghai; Wu, Hongjun; Wang, Peng
2015-01-01
One-dimensional nanocomposites of metal-oxide and noble metal were expected to present superior performance for nonenzymatic glucose detection due to its good conductivity and high catalytic activity inherited from noble metal and metal oxide respectively. As a proof of concept, we synthesized gold and copper oxide (Au/CuO) composite with unique one-dimensional nanocauliflowers structure. Due to the nature of the synthesis method, no any foreign binder was needed in keeping either Au or CuO in place. To the best of our knowledge, this is the first attempt in combining metal oxide and noble metal in a binder-free style for fabricating nonenzymatic glucose sensor. The Au/CuO nanocauliflowers with large electrochemical active surface and high electrolyte contact area would promise a wide linear range and high sensitive detection of glucose with good stability and reproducibility due to its good electrical conductivity of Au and high electrocatalytic activity of CuO. PMID:26068705
Enabling aqueous processing for crack-free thick electrodes
Du, Zhijia; Rollag, K. M.; Li, J.; ...
2017-04-14
Aqueous processing of thick electrodes for Li-ion cells promises to increase energy density due to increased volume fraction of active materials, and to reduce cost due to the elimination of the toxic solvents. Here in this paper this work reports the processing and characterization of aqueous processed electrodes with high areal loading and associated full pouch cell performance. Cracking of the electrode coatings becomes a critical issue for aqueous processing of the positive electrode as areal loading increases above 20–25 mg/cm 2 (~4 mAh/cm 2). Crack initiation and propagation, which was observed during drying via optical microscopy, is related tomore » the build-up of capillary pressure during the drying process. The surface tension of water was reduced by the addition of isopropyl alcohol (IPA), which led to improved wettability and decreased capillary pressure during drying. The critical thickness (areal loading) without cracking increased gradually with increasing IPA content. The electrochemical performance was evaluated in pouch cells. Electrodes processed with water/IPA (80/20 wt%) mixture exhibited good structural integrity with good rate performance and cycling performance.« less
NASA Astrophysics Data System (ADS)
Endrawati, Titin; Siregar, M. Tirtana
2018-03-01
PT Mentari Trans Nusantara is a company engaged in the distribution of goods from the manufacture of the product to the distributor branch of the customer so that the product distribution must be controlled directly from the PT Mentari Trans Nusantara Center for faster delivery process. Problems often occur on the expedition company which in charge in sending the goods although it has quite extensive networking. The company is less control over logistics management. Meanwhile, logistics distribution management control policy will affect the company's performance in distributing products to customer distributor branches and managing product inventory in distribution center. PT Mentari Trans Nusantara is an expedition company which engaged in good delivery, including in Jakarta. Logistics management performance is very important due to its related to the supply of goods from the central activities to the branches based oncustomer demand. Supply chain management performance is obviously depends on the location of both the distribution center and branches, the smoothness of transportation in the distribution and the availability of the product in the distribution center to meet the demand in order to avoid losing sales. This study concluded that the company could be more efficient and effective in minimizing the risks of loses by improve its logistic management.
Performance evaluation of subgrade stabilization with recycled materials.
DOT National Transportation Integrated Search
2016-02-29
Due to rising costs of good quality acceptable materials for remove/replace options and traditional : subgrade stabilization materials, MDOT is in need to identify potential recycled materials to treat : unacceptable subgrade soils. Use of recycled m...
External fixation of "intertrochanteric" fractures.
Gani, Naseem Ul; Kangoo, Khursheed Ahmed; Bashir, Arshad; Muzaffer, Rahil; Bhat, Mohammad Farooq; Farooq, Munir; Badoo, Abdul Rashid; Dar, Imtiyaz Hussian; Wani, Mudassir Maqbool
2009-10-10
In developing countries, due to limited availability of modern anesthesia and overcrowding of the hospitals with patients who need surgery, high-risk patients with "intertrochanteric" fractures remain unsuita ble for open reduction and internal fixation.The aim of this study was to analyze the results of external fixation of "intertrochanteric" fractures in high-risk geriatric patients in a developing country.The results of 62 ambulatory high-risk geriatric patients with a mean age of 70 years (range 58-90 years) with "intertrochanteric" fractures, in whom external fixation was performed, are reported.Eight patients died during follow-up due to medical causes unrelated to the surgical procedure. So only 54 patients were available for final assessment. Procedure is simple, performed under local anesthesia, requires less time for surgery and is associated with less blood loss. Good fixation and early ambulation was achieved in most of the patients. Average time to union was 14 weeks. Thirty-one patients developed superficial pin tract infection and 28 patients had average shortening of 15 mm due to impaction and varus angulation. Functional outcome was assessed using Judet's point system. Good to excellent results were achieved in 44 patients.This study demonstrated that external fixation of "intertrochantric" fractures performed under local anesthesia offers significant advantage in ambulatory high-risk geriatric patients especially in a developing country.
DOT National Transportation Integrated Search
2010-10-01
Louisiana has been using polymer modified asphalt cement (PMAC) increasingly for : better pavement performance. More often than not, elastomers became the : asphalt modifiers of choice due to their excellent elasticity and good compatibility : with a...
NASA Astrophysics Data System (ADS)
Miyakita, Takeshi; Hatakenaka, Ryuta; Sugita, Hiroyuki; Saitoh, Masanori; Hirai, Tomoyuki
2014-11-01
For conventional Multi-Layer Insulation (MLI) blankets, it is difficult to control the layer density and the thermal insulation performance degrades due to the increase in conductive heat leak through interlayer contacts. At low temperatures, the proportion of conductive heat transfer through MLI blankets is large compared to that of radiative heat transfer, hence the decline in thermal insulation performance is significant. A new type of MLI blanket using new spacers; the Non-Interlayer-Contact Spacer MLI (NICS MLI) has been developed. This new MLI blanket uses small discrete spacers and can exclude uncertain interlayer contact between films. It is made of polyetheretherketone (PEEK) making it suitable for space use. The cross-sectional area to length ratio of the spacer is 1.0 × 10-5 m with a 10 mm diameter and 4 mm height. The insulation performance is measured with a boil-off calorimeter. Because the NICS MLI blanket can exclude uncertain interlayer contact, the test results showed good agreement with estimations. Furthermore, the NICS MLI blanket shows significantly good insulation performance (effective emissivity is 0.0046 at ordinary temperature), particularly at low temperatures, due to the high thermal resistance of this spacer.
Symmetric supercapacitor: Sulphurized graphene and ionic liquid.
Shaikh, Jasmin S; Shaikh, Navajsharif S; Kharade, Rohini; Beknalkar, Sonali A; Patil, Jyoti V; Suryawanshi, Mahesh P; Kanjanaboos, Pongsakorn; Hong, Chang Kook; Kim, Jin Hyeok; Patil, Pramod S
2018-10-01
Symmetric supercapacitor is advanced over simple supercapacitor device due to their stability over a large potential window and high energy density. Graphene is a desired candidate for supercapacitor application since it has a high surface area, good electronic conductivity and high electro chemical stability. There is a pragmatic use of ionic liquid electrolyte for supercapacitor due to its stability over a large potential window, good ionic conductivity and eco-friendly nature. For high performance supercapacitor, the interaction between ionic liquid electrolyte and graphene are crucial for better charge transportation. In respect of this, a three-dimensional (3D) nanoporous honeycomb shaped sulfur embedded graphene (S-graphene) has been synthesized by simple chemical method. Here, the fabrication of high performance symmetric supercapacitor is done by using S-graphene as an electrode and [BMIM-PF 6 ] as an electrolyte. The particular architecture of S-graphene benefited to reduce the ion diffusion resistance, providing the large surface area for charge transportation and efficient charge storage. The S-graphene and ionic liquid-based symmetric supercapacitor device showed the large potential window of 3.2 V with high energy density 124 Wh kg -1 at 0.2 A g -1 constant applied current density. Furthermore, this device shows good cycling performance (stability) with a capacitive retention of 95% over 20,000 cycles at a higher current density of 2 A g -1 . Copyright © 2018 Elsevier Inc. All rights reserved.
Optimal design of a main driving mechanism for servo punch press based on performance atlases
NASA Astrophysics Data System (ADS)
Zhou, Yanhua; Xie, Fugui; Liu, Xinjun
2013-09-01
The servomotor drive turret punch press is attracting more attentions and being developed more intensively due to the advantages of high speed, high accuracy, high flexibility, high productivity, low noise, cleaning and energy saving. To effectively improve the performance and lower the cost, it is necessary to develop new mechanisms and establish corresponding optimal design method with uniform performance indices. A new patented main driving mechanism and a new optimal design method are proposed. In the optimal design, the performance indices, i.e., the local motion/force transmission indices ITI, OTI, good transmission workspace good transmission workspace(GTW) and the global transmission indices GTIs are defined. The non-dimensional normalization method is used to get all feasible solutions in dimensional synthesis. Thereafter, the performance atlases, which can present all possible design solutions, are depicted. As a result, the feasible solution of the mechanism with good motion/force transmission performance is obtained. And the solution can be flexibly adjusted by designer according to the practical design requirements. The proposed mechanism is original, and the presented design method provides a feasible solution to the optimal design of the main driving mechanism for servo punch press.
Wang, Yaoguang; Zhang, Yong; Wu, Dan; Ma, Hongmin; Pang, Xuehui; Fan, Dawei; Wei, Qin; Du, Bin
2017-01-01
In this work, a novel label-free electrochemical immunosensor was developed for the quantitative detection of alpha fetoprotein (AFP). Multifunctionalized graphene nanocomposites (TB-Au-Fe3O4-rGO) were applied to modify the electrode to achieve the amplification of electrochemical signal. TB-Au-Fe3O4-rGO includes the advantages of graphene, ferroferric oxide nanoparticles (Fe3O4 NPs), gold nanoparticles (Au NPs) and toluidine blue (TB). As a kind of redox probe, TB can produce the electrochemical signal. Graphene owns large specific surface area, high electrical conductivity and good adsorption property to load a large number of TB. Fe3O4 NPs have good electrocatalytic performance towards the redox of TB. Au NPs have good biocompatibility to capture the antibodies. Due to the good electrochemical performance of TB-Au-Fe3O4-rGO, the effective and sensitive detection of AFP was achieved by the designed electrochemical immunosensor. Under optimal conditions, the designed immunosensor exhibited a wide linear range from 1.0 × 10−5 ng/mL to 10.0 ng/mL with a low detection limit of 2.7 fg/mL for AFP. It also displayed good electrochemical performance including good reproducibility, selectivity and stability, which would provide potential applications in the clinical diagnosis of other tumor markers. PMID:28186128
Schäfer, Ulrich; Schirmer, Johannes; Niklas, Schofer; Harmel, Eva; Deuschl, Florian; Conradi, Lenard
2017-12-20
Here we will describe the first case of a novel JenaValve design (JenaValve Technology, Irvine, CA, USA) using the transfemoral approach in a 78-year-old female patient with pure aortic regurgitation. The implantation was successfully performed with good haemodynamics and good clinical outcome at six-month follow- up. The technology is especially appealing in non-calcified anatomies due to the clipping mechanism which was previously utilised in the transapical design.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Alexova, J.; Sirova, M.; Rais, J.
2008-07-01
Within the framework of the ARTIST project of total fuel retreatment with ecological mixtures of solvents and extractants containing only C, H, O, and N atoms, a process segment of extraction of {sup 137}Cs from acidic stream was developed. The process with 25,27-Bis(1-octyloxy)calix[4]arene-crown- 6, DOC[4]C6, dissolved at its 0.01 M concentration in a mixture of 90 vol % 1-octanol and 10% dihexyl octanamide, DHOA was proposed as a viable variant due to its good multicycle performance, even with irradiated solvent, and due to the good chemical stability of the chosen combination of solvent mixture. (authors)
Comparing spatial regression to random forests for large environmental data sets
Environmental data may be “large” due to number of records, number of covariates, or both. Random forests has a reputation for good predictive performance when using many covariates, whereas spatial regression, when using reduced rank methods, has a reputatio...
Ultrafast detection in particle physics and positron emission tomography using SiPMs
NASA Astrophysics Data System (ADS)
Dolenec, R.; Korpar, S.; Križan, P.; Pestotnik, R.
2017-12-01
Silicon photomultiplier (SiPM) photodetectors perform well in many particle and medical physics applications, especially where good efficiency, insensitivity to magnetic field and precise timing are required. In Cherenkov time-of-flight positron emission tomography the requirements for photodetector performance are especially high. On average only a couple of photons are available for detection and the best possible timing resolution is needed. Using SiPMs as photodetectors enables good detection efficiency, but the large sensitive area devices needed have somewhat limited time resolution for single photons. We have observed an additional degradation of the timing at very low light intensities due to delayed events in distribution of signals resulting from multiple fired micro cells. In this work we present the timing properties of AdvanSiD ASD-NUV3S-P-40 SiPM at single photon level picosecond laser illumination and a simple modification of the time-walk correction algorithm, that resulted in reduced degradation of timing resolution due to the delayed events.
Fabrication of high-performance supercapacitors based on transversely oriented carbon nanotubes
NASA Astrophysics Data System (ADS)
Markoulidis, F.; Lei, C.; Lekakou, C.
2013-04-01
High-performance supercapacitors with organic electrolyte 1 M TEABF4 (tetraethyl ammonium tetrafluoroborate) in PC (propylene carbonate) were fabricated and tested, based on multiwall carbon nanotubes (MWNTs) deposited by electrophoresis on three types of alternative substrates: aluminium foil, ITO (indium tin oxide) coated PET (polyethylene terephthalate) film and PET film. In all cases, SEM (scanning electron microscopy) and STEM (scanning transmission electron microscopy) micrographs demonstrated that protruding, transversely oriented MWNT structures were formed, which should increase the transverse conductivity of these MWNT electrodes. The best supercapacitor cell of MWNT electrodes deposited on aluminium foil displayed good transverse orientation of the MWNT structures as well as an in-plane MWNT network at the feet of the protruding structures, which ensured good in-plane conductivity. Capacitor cells with MWNT electrodes deposited either on ITO-coated PET film or on PET film demonstrated lower but still very good performance due to the high density of transversely oriented MWNT structures (good transverse conductivity) but some in-plane inhomogeneities. Capacitor cells with drop-printed MWNTs on aluminium foil, without any transverse orientation, had 16-30 times lower specific capacitance and 5-40 times lower power density than the capacitor cells with the electrophoretically deposited MWNT electrodes.
Postflight analysis of the EVCS-LM communications link for the Apollo 15 mission
NASA Technical Reports Server (NTRS)
Royston, C. L., Jr.; Eggers, D. S.
1972-01-01
Data from the Apollo 15 mission were used to compare the actual performance of the EVCS to LM communications link with the preflight performance predictions. Based on the results of the analysis, the following conclusions were made: (1) The radio transmission loss data show good correlation with predictions during periods when the radio line of sight was obscured. (2) The technique of predicting shadow losses due to obstacles in the radio line of sight provides a good estimate of the actual shadowing loss. (3) When the transmitter was on an upslope, the radio transmission loss approached the free space loss values as the line of sight to the LM was regained.
External fixation of “intertrochanteric” fractures
Gani, Naseem ul; Kangoo, Khursheed Ahmed; Bashir, Arshad; Muzaffer, Rahil; Bhat, Mohammad Farooq; Farooq, Munir; Badoo, Abdul Rashid; Dar, Imtiyaz Hussian; Wani, Mudassir Maqbool
2009-01-01
In developing countries, due to limited availability of modern anesthesia and overcrowding of the hospitals with patients who need surgery, high-risk patients with “intertrochanteric” fractures remain unsuita ble for open reduction and internal fixation. The aim of this study was to analyze the results of external fixation of “intertrochanteric” fractures in high-risk geriatric patients in a developing country. The results of 62 ambulatory high-risk geriatric patients with a mean age of 70 years (range 58–90 years) with “intertrochanteric” fractures, in whom external fixation was performed, are reported. Eight patients died during follow-up due to medical causes unrelated to the surgical procedure. So only 54 patients were available for final assessment. Procedure is simple, performed under local anesthesia, requires less time for surgery and is associated with less blood loss. Good fixation and early ambulation was achieved in most of the patients. Average time to union was 14 weeks. Thirty-one patients developed superficial pin tract infection and 28 patients had average shortening of 15 mm due to impaction and varus angulation. Functional outcome was assessed using Judet's point system. Good to excellent results were achieved in 44 patients. This study demonstrated that external fixation of “intertrochantric” fractures performed under local anesthesia offers significant advantage in ambulatory high-risk geriatric patients especially in a developing country. PMID:21808680
Human Resource Development, Ethics, and the Social Good
ERIC Educational Resources Information Center
Quinn, Floyd F.
2018-01-01
Businesses can achieve competitive advantage and better productivity and performance by attracting and developing exceptional employees, by caring for and listening to stakeholders, and by avoiding financial and reputational damage due to unethical and illegal behaviors. As a profession, human resource development (HRD) engages in practices that…
NASA Astrophysics Data System (ADS)
Ángel Prósper Fernández, Miguel; Casal, Carlos Otero; Canoura Fernández, Felipe; Miguez-Macho, Gonzalo
2017-04-01
Regional meteorological models are becoming a generalized tool for forecasting wind resource, due to their capacity to simulate local flow dynamics impacting wind farm production. This study focuses on the production forecast and validation of a real onshore wind farm using high horizontal and vertical resolution WRF (Weather Research and Forecasting) model simulations. The wind farm is located in Galicia, in the northwest of Spain, in a complex terrain region with high wind resource. Utilizing the Fitch scheme, specific for wind farms, a period of one year is simulated with a daily operational forecasting set-up. Power and wind predictions are obtained and compared with real data provided by the management company. Results show that WRF is able to yield good wind power operational predictions for this kind of wind farms, due to a good representation of the planetary boundary layer behaviour of the region and the good performance of the Fitch scheme under these conditions.
NASA Astrophysics Data System (ADS)
Zuhudi, Nurul Zuhairah Mahmud; Minhat, Mulia; Shamsuddin, Mohd Hafizi; Isa, Mohd Dali; Nur, Nurhayati Mohd
2017-12-01
In recent years, natural fabric thermoplastic composites such as flax have received much attention due to its attractive capabilities for structural applications. It is crucial to study the processing of flax fabric materials in order to achieve good quality and cost-effectiveness in fibre reinforced composites. Though flax fabric has been widely utilized for several years in composite applications due to its high strength and abundance in nature, much work has been concentrated on short flax fibre and very little work focused on using flax fabric. The effectiveness of the flax fabric is expected to give higher strength performance due to its structure but the processing needs to be optimised. Flax fabric composites were fabricated using compression moulding due to its simplicity, gives good surface finish and relatively low cost in terms of labour and production. Further, the impregnation of the polymer into the fabric is easier in this process. As the fabric weave structure contributes to the impregnation quality which leads to the overall performance, the processing parameters of consolidation i.e. pressure, time, and weight fraction of fabric were optimized using the Taguchi method. This optimization enhances the consolidation quality of the composite by improving the composite mechanical properties, three main tests were conducted i.e. tensile, flexural and impact test. It is observed that the processing parameter significantly affected the consolidation and quality of composite.
Team research at the biology-mathematics interface: project management perspectives.
Milton, John G; Radunskaya, Ami E; Lee, Arthur H; de Pillis, Lisette G; Bartlett, Diana F
2010-01-01
The success of interdisciplinary research teams depends largely upon skills related to team performance. We evaluated student and team performance for undergraduate biology and mathematics students who participated in summer research projects conducted in off-campus laboratories. The student teams were composed of a student with a mathematics background and an experimentally oriented biology student. The team mentors typically ranked the students' performance very good to excellent over a range of attributes that included creativity and ability to conduct independent research. However, the research teams experienced problems meeting prespecified deadlines due to poor time and project management skills. Because time and project management skills can be readily taught and moreover typically reflect good research practices, simple modifications should be made to undergraduate curricula so that the promise of initiatives, such as MATH-BIO 2010, can be implemented.
An experimental investigation of hingeless helicopter rotor-body stability in hover
NASA Technical Reports Server (NTRS)
Bousman, W. G.
1978-01-01
Model tests of a 1.62 m diameter rotor were performed to investigate the aeromechanical stability of coupled rotor-body systems in hover. Experimental measurements were made of modal frequencies and damping over a wide range of rotor speeds. Good data were obtained for the frequencies of the rotor lead-lag regressing mode. The quality of the damping measurements of the body modes was poor due to nonlinear damping in the gimbal ball bearings. Simulated vacuum testing was performed using substitute blades of tantalum that reduced the effective lock number to 0.2% of the model scale value while keeping the blade inertia constant. The experimental data were compared with theoretical predictions, and the correlation was in general very good.
High Temperature Stable Separator for Lithium Batteries Based on SiO2 and Hydroxypropyl Guar Gum
Carvalho, Diogo Vieira; Loeffler, Nicholas; Kim, Guk-Tae; Passerini, Stefano
2015-01-01
A novel membrane based on silicon dioxide (SiO2) and hydroxypropyl guar gum (HPG) as binder is presented and tested as a separator for lithium-ion batteries. The separator is made with renewable and low cost materials and an environmentally friendly manufacturing processing using only water as solvent. The separator offers superior wettability and high electrolyte uptake due to the optimized porosity and the good affinity of SiO2 and guar gum microstructure towards organic liquid electrolytes. Additionally, the separator shows high thermal stability and no dimensional-shrinkage at high temperatures due to the use of the ceramic filler and the thermally stable natural polymer. The electrochemical tests show the good electrochemical stability of the separator in a wide range of potential, as well as its outstanding cycle performance. PMID:26512701
Robust Temperature Control of a Thermoelectric Cooler via μ -Synthesis
NASA Astrophysics Data System (ADS)
Kürkçü, Burak; Kasnakoğlu, Coşku
2018-02-01
In this work robust temperature control of a thermoelectric cooler (TEC) via μ -synthesis is studied. An uncertain dynamical model for the TEC that is suitable for robust control methods is derived. The model captures variations in operating point due to current, load and temperature changes. A temperature controller is designed utilizing μ -synthesis, a powerful method guaranteeing robust stability and performance. For comparison two well-known control methods, namely proportional-integral-derivative (PID) and internal model control (IMC), are also realized to benchmark the proposed approach. It is observed that the stability and performance on the nominal model are satisfactory for all cases. On the other hand, under perturbations the responses of PID and IMC deteriorate and even become unstable. In contrast, the μ -synthesis controller succeeds in keeping system stability and achieving good performance under all perturbations within the operating range, while at the same time providing good disturbance rejection.
Automatic Generation of Directive-Based Parallel Programs for Shared Memory Parallel Systems
NASA Technical Reports Server (NTRS)
Jin, Hao-Qiang; Yan, Jerry; Frumkin, Michael
2000-01-01
The shared-memory programming model is a very effective way to achieve parallelism on shared memory parallel computers. As great progress was made in hardware and software technologies, performance of parallel programs with compiler directives has demonstrated large improvement. The introduction of OpenMP directives, the industrial standard for shared-memory programming, has minimized the issue of portability. Due to its ease of programming and its good performance, the technique has become very popular. In this study, we have extended CAPTools, a computer-aided parallelization toolkit, to automatically generate directive-based, OpenMP, parallel programs. We outline techniques used in the implementation of the tool and present test results on the NAS parallel benchmarks and ARC3D, a CFD application. This work demonstrates the great potential of using computer-aided tools to quickly port parallel programs and also achieve good performance.
Inventory Control System by Using Vendor Managed Inventory (VMI)
NASA Astrophysics Data System (ADS)
Sabila, Alzena Dona; Mustafid; Suryono
2018-02-01
The inventory control system has a strategic role for the business in managing inventory operations. Management of conventional inventory creates problems in the stock of goods that often runs into vacancies and excess goods at the retail level. This study aims to build inventory control system that can maintain the stability of goods availability at the retail level. The implementation of Vendor Managed Inventory (VMI) method on inventory control system provides transparency of sales data and inventory of goods at retailer level to supplier. Inventory control is performed by calculating safety stock and reorder point of goods based on sales data received by the system. Rule-based reasoning is provided on the system to facilitate the monitoring of inventory status information, thereby helping the process of inventory updates appropriately. Utilization of SMS technology is also considered as a medium of collecting sales data in real-time due to the ease of use. The results of this study indicate that inventory control using VMI ensures the availability of goods ± 70% and can reduce the accumulation of goods ± 30% at the retail level.
NASA Astrophysics Data System (ADS)
Munusami, Ravindiran; Yakkala, Bhaskar Rao; Prabhakar, Shankar
2013-12-01
Magnetic tunnel junction were made by inserting the magnetic materials between the source, channel and the drain of the High Electron Mobility Transistor (HEMT) to enhance the performance. Material studio software package was used to design the superlattice layers. Different cases were analyzed to optimize the performance of the device by placing the magnetic material at different positions of the device. Simulation results based on conductivity reveals that the device has a very good electron transport due to the magnetic materials and will amplify very low frequency signals.
Kong, Xiangjin; Liu, Junhai
2014-01-01
The influence of the amount of alumina binders on the catalytic performance of Ni/HZSM-5 for hydrodeoxygenation of cyclohexanone was investigated in a fixed-bed reactor. N2 sorption, X-ray diffraction, H2-chemisorption and temperature-programmed desorption of ammonia were used to characterize the catalysts. It can be observed that the Ni/HZSM-5 catalyst bound with 30 wt.% alumina binder exhibited the best catalytic performance. The high catalytic performance may be due to relatively good Ni metal dispersion, moderate mesoporosity, and proper acidity of the catalyst. PMID:25009974
Kong, Xiangjin; Liu, Junhai
2014-01-01
The influence of the amount of alumina binders on the catalytic performance of Ni/HZSM-5 for hydrodeoxygenation of cyclohexanone was investigated in a fixed-bed reactor. N2 sorption, X-ray diffraction, H2-chemisorption and temperature-programmed desorption of ammonia were used to characterize the catalysts. It can be observed that the Ni/HZSM-5 catalyst bound with 30 wt.% alumina binder exhibited the best catalytic performance. The high catalytic performance may be due to relatively good Ni metal dispersion, moderate mesoporosity, and proper acidity of the catalyst.
MEMS-based wide-bandwidth electromagnetic energy harvester with electroplated nickel structure
NASA Astrophysics Data System (ADS)
Sun, Shi; Dai, Xuhan; Sun, Yunna; Xiang, Xiaojian; Ding, Guifu; Zhao, Xiaolin
2017-11-01
A novel nickel-based nonlinear electromagnetic energy harvester has been designed, fabricated, and characterized in this work. Electroplated nickel is very suitable for a stretching-based mechanism to broaden the bandwidth due to its good process and mechanical properties. A strong hardening nonlinearity is induced due to the large deformation of the thin nickel based guided-beam structure. Combining the merits of both the mechanical properties and guided-beam structure, the energy harvester shows good bandwidth performance. It is found that increasing the thickness of the central platform could guarantee nonlinearity. Static and dynamic models of the energy harvester are simulated and validated. Test results show that the energy harvester has good repeatability without any destruction under a large deformation condition. At the acceleration of 0.5 g, comparative large bandwidths of 129 and 59 Hz are obtained for displacement and RMS output voltage, respectively. Power output of 3.4 µW and normalized power density of 125.92 µW cm-3 g-2 are achieved with the load resistance of 38 Ω.
Limakrisna, Nandan; Yoserizal, Syahril
2016-01-01
Indonesian banking industry has experienced up and down as can be seen after Pakto '88, in which the number of new banks grew rapidly, but after the 1997-1998 financial crisis, a lot of banks were liquidated due to the deteriorating financial condition and violation of the precautionary principles by bank management. The purpose of this research is to determine and analyze the effects of good corporate governance, information technology, HR competencies on competitive advantage and its implication on marketing performance. The method used in this research was a descriptive survey and explanatory survey with a sample size of 320 respondents, and the data analysis methods used are structural equation modeling. Based on the results of the research, the findings obtained from good corporate governance, information technology, HR competencies have a significant effect on competitive advantage on the performance of marketing. However, when seen in part, competitive advantage has a dominant effect on marketing performance.
Novel Observer Scheme of Fuzzy-MRAS Sensorless Speed Control of Induction Motor Drive
NASA Astrophysics Data System (ADS)
Chekroun, S.; Zerikat, M.; Mechernene, A.; Benharir, N.
2017-01-01
This paper presents a novel approach Fuzzy-MRAS conception for robust accurate tracking of induction motor drive operating in a high-performance drives environment. Of the different methods for sensorless control of induction motor drive the model reference adaptive system (MRAS) finds lot of attention due to its good performance. The analysis of the sensorless vector control system using MRAS is presented and the resistance parameters variations and speed observer using new Fuzzy Self-Tuning adaptive IP Controller is proposed. In fact, fuzzy logic is reminiscent of human thinking processes and natural language enabling decisions to be made based on vague information. The present approach helps to achieve a good dynamic response, disturbance rejection and low to plant parameter variations of the induction motor. In order to verify the performances of the proposed observer and control algorithms and to test behaviour of the controlled system, numerical simulation is achieved. Simulation results are presented and discussed to shown the validity and the performance of the proposed observer.
An ANSERLIN array for mobile satellite applications
NASA Technical Reports Server (NTRS)
Colomb, F. Y.; Kunkee, D. B.; Mayes, P. E.; Smith, D. W.; Jamnejad, V.
1990-01-01
Design, analysis, construction, and test of linear arrays of ANSERLIN (annular sector, radiating line) elements are reported and discussed. Due to feeding simplicity and easy construction as well as good CP performance, a planar array composed of a number of such linear arrays each producing a shaped beam tilted in elevation, is a good candidate as a vehicle-mounted mechanically steered antenna for mobile satellite applications. A single level construction technique was developed that makes this type of array very cost competitive with other low-profile arrays. An asymmetric 19.5 inch long four-element array was fabricated and tested with reasonable performance. A smaller five-element symmetric array (16 inch long) was also designed and tested capable of operating in either sense of circular polarization. Efforts were made to successfully reduce this effect.
Linear quadratic Gaussian and feedforward controllers for the DSS-13 antenna
NASA Technical Reports Server (NTRS)
Gawronski, W. K.; Racho, C. S.; Mellstrom, J. A.
1994-01-01
The controller development and the tracking performance evaluation for the DSS-13 antenna are presented. A trajectory preprocessor, linear quadratic Gaussian (LQG) controller, feedforward controller, and their combination were designed, built, analyzed, and tested. The antenna exhibits nonlinear behavior when the input to the antenna and/or the derivative of this input exceeds the imposed limits; for slewing and acquisition commands, these limits are typically violated. A trajectory preprocessor was designed to ensure that the antenna behaves linearly, just to prevent nonlinear limit cycling. The estimator model for the LQG controller was identified from the data obtained from the field test. Based on an LQG balanced representation, a reduced-order LQG controller was obtained. The feedforward controller and the combination of the LQG and feedforward controller were also investigated. The performance of the controllers was evaluated with the tracking errors (due to following a trajectory) and the disturbance errors (due to the disturbances acting on the antenna). The LQG controller has good disturbance rejection properties and satisfactory tracking errors. The feedforward controller has small tracking errors but poor disturbance rejection properties. The combined LQG and feedforward controller exhibits small tracking errors as well as good disturbance rejection properties. However, the cost for this performance is the complexity of the controller.
Evaluation of Force Transfer Around Openings - Experimental and Analytical Studies
Borjen Yeh; Tom Skaggs; Frank Lam; Minghao Li; Douglas Rammer; James Wacker
2011-01-01
Wood structural panel (WSP) sheathed shear walls and diaphragms are the primary lateral-load-resistingelements in wood-frame construction. The historical performance of light-frame structures in North America is very good due, in part, to model building codes that are designed to safeguard life safety. These model building codes have spawned continual improvement and...
Modelling Force Transfer Around Openings of Full-Scale Shear Walls
Tom Skaggs; Borjen Yeh; Frank Lam; Minghao Li; Doug Rammer; James Wacker
2011-01-01
Wood structural panel (WSP) sheathed shear walls and diaphragms are the primary lateralload-resisting elements in wood-frame construction. The historical performance of lightframe structures in North America has been very good due, in part, to model building codes that are designed to preserve life safety. These model building codes have spawned continual improvement...
Li, Yuqi; Zhang, Hui; Fan, Mizi; Zhuang, Jiandong; Chen, Lihui
2016-09-14
Oil-water separation has recently become an important subject due to the increasing incidence of oil spills. Materials with underwater superoleophobic properties have aroused considerable interest due to their cost-effectiveness, environmental friendliness and anti-fouling properties. This paper presents a robust salt-tolerant superoleophobic aerogel inspired by seaweed used without any further chemical modification for oil-seawater separation. The green aerogel is prepared by freeze-drying of sodium alginate (SA)-nanofibrillated cellulose (NFC) using Ca 2+ ions as the crosslinking agent. The three-dimensional (3D) interconnected network structure of the developed aerogel ensures its high mechanical strength and good flexibility. The natural hydrophilicity of the polysaccharides contained in the aerogel ensures its excellent underwater superoleophobicity, antifouling and salt-tolerance properties. More impressively, the as-prepared aerogel can even keep its underwater superoleophobicity and high hydrophilicity after being immersed in seawater for 30 days, indicating its good stability in marine environments. Furthermore, the aerogel could separate oil-seawater mixtures with a high separation efficiency (of up to 99.65%) and good reusability (at least 40 cycles). The facile and green fabrication process combined with the excellent separation performance and good reusability makes it possible to develop engineering materials for oil-water separation in marine environments.
Yu, Peng; Cao, Gejin; Yi, Sha; Zhang, Xiong; Li, Chen; Sun, Xianzhong; Wang, Kai; Ma, Yanwei
2018-03-29
Two-dimensional (2D) MXenes have a very good application prospect in the field of electrochemical energy storage due to their metallic conductivity, high volumetric capacity, mechanical and thermal stability. Herein, we report the preparation of titanium carbide (Ti3C2Tx)/carbon nanotube (CNT) flexible self-supporting composite films by vacuum filtration. The CNTs can effectively prevent Ti3C2Tx from stacking and improve the electrochemical performance. The as-fabricated Ti3C2Tx/CNT film shows a high reversible capacity of 489 mA h g-1 at a current density of 50 mA g-1 together with good cycling performance. The full-cell lithium-ion capacitor (LIC) is assembled using the Ti3C2Tx/CNT film as the anode and activated carbon as the cathode. The LIC exhibits a high energy density of 67 Wh kg-1 (based on the total weight of the anode and the cathode), and a good capacity retention of 81.3% after 5000 cycles. These results suggest that Ti3C2Tx-CNT films are promising as anode materials for lithium ion capacitors.
Analyzing patient's waiting time in emergency & trauma department in public hospital - A case study
NASA Astrophysics Data System (ADS)
Roslan, Shazwa; Tahir, Herniza Md; Nordin, Noraimi Azlin Mohd; Zaharudin, Zati Aqmar
2014-09-01
Emergency and Trauma Department (ETD) is an important element for a hospital. It provides medical service, which operates 24 hours a day in most hospitals. However overcrowding is not exclusion for ETD. Overflowing occurs due to affordable services provided by public hospitals, since it is funded by the government. It is reported that a patient attending ETD must be treated within 90 minutes, in accordance to achieve the Key Performance Indicator (KPI). However, due to overcrowd situations, most patients have to wait longer than the KPI standard. In this paper, patient's average waiting time is analyzed. Using Chi-Square Test of Goodness, patient's inter arrival per hour is also investigated. As conclusion, Monday until Wednesday was identified as the days that exceed the KPI standard while Chi-Square Test of Goodness showed that the patient's inter arrival is independent and random.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Ogawa, Makoto, E-mail: waseda.ogawa@gmail.com; Department of Earth Sciences, Waseda University, 1-6-1 Nishiwaseda, Shinjuku-ku, Tokyo 169-8050; Morita, Masashi, E-mail: m-masashi@y.akane.waseda.jp
2013-10-15
A layered titanate, potassium lithium titanate, with the size range from 0.1 to 30 µm was prepared to show the effects of the particle size on the materials performance. The potassium lithium titanate was prepared by solid-state reaction as reported previously, where the reaction temperature was varied. The reported temperature for the titanate preparation was higher than 800 °C, though 600 °C is good enough to obtain single-phase potassium lithium titanate. The lower temperature synthesis is cost effective and the product exhibit better performance as photocatalysts due to surface reactivity. - Graphical abstract: Finite particle of a layered titanate, potassiummore » lithium titanate, was prepared by solid-state reaction at lower temperature to show modified materials performance. Display Omitted - Highlights: • Potassium lithium titanate was prepared by solid-state reaction. • Lower temperature reaction resulted in smaller sized particles of titanate. • 600 °C was good enough to obtain single phased potassium lithium titanate. • The product exhibited better performance as photocatalyst.« less
Determination of properties of PVE lubricants with HFC refrigerants[PolyVinylEther
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kaneko, Masato; Sakanoue, Shuichi; Tazaki, Toshihiro
1999-07-01
Polyalkyleneglycol (PAG) and polyol ester (POE) have been developed as refrigeration lubricants, used with HFC134a. PAG is used for automotive air conditioning systems and POE is used for domestic reciprocating refrigerators and for A/C systems. Although PAG exhibits good lubricity performance, it is difficult to use for domestic reciprocating refrigerators due to its low dielectric property. POE is difficult to use for automotive A/C systems, due to hydrolysis and poor lubricity performance. Polyvinylether (PVE) can be used in place of PAG and POE with HFC refrigerants. PVE is used for A/C systems as well as refrigerator and freezer applications. PVEmore » is an ideal lubricant for use with HFCs.« less
Full-scale shear wall tests for force transfer around openings
Tom Skaggs; Borjen Yeh; Frank Lam; Douglas Rammer; James Wacker
2010-01-01
Wood structural panel sheathed shear walls and diaphragms are the primary lateral-load resisting elements in wood-frame construction. The historical performance of light-frame structures in North America are very good due, in part, to model building codes that are designed to preserve life safety, as well as the inherent redundancy of wood-frame construction using wood...
Magnesium-enriched hydroxyapatite as bone filler in an ameloblastoma mandibular defect
Grigolato, Roberto; Pizzi, Natalia; Brotto, Maria C; Corrocher, Giovanni; Desando, Giovanna; Grigolo, Brunella
2015-01-01
The aim of this study was to evaluate the clinical performance of a magnesium-enriched hydroxyapatite biomaterial used as bone substitute in a case of mandibular ameloblastoma treated with conservative surgery. A 63 year old male patient was treated for an ameloblastoma in the anterior mandibular profile. After tissue excision, the bone defect was filled with a synthetic hydroxyapatite biomaterial enriched with magnesium ions, in order to promote bone tissue regeneration and obtain a good aesthetic result. Twenty-five months after surgery, due to ameloblastoma recurrence in an area adjacent to the previously treated one, the patient underwent to a further surgery. In that occasion the surgeon performed a biopsy in the initially treated area, in order to investigate the nature of the newly-formed tissue and to evaluate the bone regenerative potential of this biomaterial by clinical, radiographic and histological analyses. The clinical, radiographic and histological evaluations showed various characteristics of bone remodeling stage with an ongoing osteogenic formation and a good osteo-integration. In conclusion, magnesium-enriched hydroxyapatite used as bone substitute in a mandibular defect due to ameloblastoma excision showed an effective bone regeneration at 25 months follow-up, demonstrating an excellent biocompatibility and a high osteo-integration property. PMID:25784998
Gao, Xiang; Liu, Shaojun; Zhang, Yang; Luo, Zhongyang; Cen, Kefa
2011-04-15
Several metal-doped activated carbons (Fe, Co, Ni, V, Mn, Cu and Ce) were prepared and characterized. The results of N(2) adsorption-desorption, X-ray diffraction, and X-ray photoelectron spectroscopy indicated that some metals (Cu and Fe) were partly reduced by carbon during preparation. Activity tests for the removal of SO(2) and the selective catalytic reduction of NO with ammonia were carried out. Due to different physicochemical properties, different pathways for the SO(2) removal had been put out, i.e., catalytic oxidation, direct reaction and adsorption. This classification depended on the standard reduction potentials of metal redox pairs. Samples impregnated with V, Ce and Cu showed good activity for NO reduction by NH(3), which was also ascribed to the reduction potential values of metal redox pairs. Ce seemed to be a promising alternative to V due to the higher activity in NO reduction and the nontoxic property. A metal cation which could easily convert between the two valences seemed to be crucial to the good performance of both SO(2) and NO removal, just like V and Cu. Copyright © 2011 Elsevier B.V. All rights reserved.
Fritsch, Julia; Rose, Marcus; Wollmann, Philipp; Böhlmann, Winfried; Kaskel, Stefan
2010-01-01
We present new element organic frameworks based on Sn, Sb and Bi atoms connected via organic linkers by element-carbon bonds. The open frameworks are characterized by specific surface areas (BET) of up to 445 m2 g-1 and a good stability under ambient conditions resulting from a highly hydrophobic inner surface. They show good performance as heterogeneous catalysts in the cyanosylilation of benzaldehyde as a test reaction. Due to their catalytic activity, this class of materials might be able to replace common homogeneous element-organic and often highly toxic catalysts especially in the food industry.
NASA Astrophysics Data System (ADS)
Li, Jing; Xie, Huaqing; Li, Yang; Liu, Jie; Li, Zhuxin
Graphene nanosheets/polyaniline nanofibers (GNS/PANI) composites are synthesized via in situ polymerization of aniline monomer in HClO 4 solution. The PANI nanofibers homogeneously coating on the surface of GNS greatly improve the charge transfer reaction. The GNS/PANI composites exhibit better electrochemical performances than the pure individual components. A remarkable specific capacitance of 1130 F g -1 (based on GNS/PANI composites) is obtained at a scan rate of 5 mV s -1 in 1 M H 2SO 4 solution compared to 402 F g -1 for pure PANI and 270 F g -1 for GNS. The excellent performance is not only due to the GNS which can provide good electrical conductivity and high specific surface area, but also associate with a good redox activity of ordered PANI nanofibers. Moreover, the GNS/PANI composites present excellent long cycle life with 87% specific capacitance retained after 1000 charge/discharge processes. The resulting composites are promising electrode materials for high-performance electrical energy storage devices.
Shape control of Co3O4 micro-structures for high-performance gas sensor
NASA Astrophysics Data System (ADS)
Zhou, Qu; Zeng, Wen
2018-01-01
Recently, spinel cobalt oxide (Co3O4) structure has been widely investigated due to its excellent sensitivity towards various noxious gases and good response/recovery speed at low concentration. In this work, we designed and synthesized two kinds of different Co3O4 micro-structure (cube and octahedron) with a similar size. After fabricating them into gas sensors, we found that the crystal plane structure of Co3O4 has an important effect on its gas sensing performance. Furthermore, the {111} planes of Co3O4may be more sensitive than {100} planes to various testing gases. Co3O4 octahedrons micro-structure exhibits an excellent sensitivity (about 12.6), good response/recovery speed and cycling stability (no decline even after 2 days) under 50 ppm ethanol gases at working temperature of 200 °C. As such, thisCo3O4 octahedrons micro-structure is a promising candidate for a high-performance gas sensing material.
NASA Astrophysics Data System (ADS)
Lee, Byung-Gwan; Lee, Seung-Hwan
2017-03-01
We report the electrochemical performance of asymmetric hybrid supercapacitors composed of granule Li4Ti5O12 as an anode and activated carbon as a cathode with different current densities. It is demonstrated that the hybrid supercapacitors show good initial discharge capacities were ranged from 39.8 to 46.4 F g-1 in the current densities range of 0.3-1 A g-1. The performance degradation is proportional to the current density due to quick gassing, resulting from H2O and HF formation. In particular, the hybrid supercapacitors show the pretty good cycling stability of 97.4%, even at the high current density of 0.8 A g-1, which are among most important performance in the real application for energy storage devices. Therefore, we believe that hybrid supercapacitors using granule Li4Ti5O12/activated carbon are eligible for the promising next generation energy devices.
DeWall, C Nathan; Baumeister, Roy F; Vohs, Kathleen D
2008-12-01
Seven experiments showed that the effects of social acceptance and social exclusion on self-regulatory performance depend on the prospect of future acceptance. Excluded participants showed decrements in self-regulation, but these decrements were eliminated if the self-regulation task was ostensibly a diagnostic indicator of the ability to get along with others. No such improvement was found when the task was presented as diagnostic of good health. Accepted participants, in contrast, performed relatively poorly when the task was framed as a diagnostic indicator of interpersonally attractive traits. Furthermore, poor performance among accepted participants was not due to self-handicapping or overconfidence. Offering accepted participants a cash incentive for self-regulating eliminated the self-regulation deficits. These findings provide evidence that the need to belong fits standard motivational patterns: Thwarting the drive intensifies it, whereas satiating it leads to temporary reduction in drive. Accepted people are normally good at self-regulation but are unwilling to exert the effort to self-regulate if self-regulation means gaining the social acceptance they have already obtained.
Whang, Liang-Ming; Wu, Yi-Ju; Lee, Ya-Chin; Chen, Hong-Wei; Fukushima, Toshikazu; Chang, Ming-Yu; Cheng, Sheng-Shung; Hsu, Shu-Fu; Chang, Cheng-Huey; Shen, Wason; Huang, Chung Kai; Fu, Ryan; Chang, Barkley
2012-10-01
This study investigated nitrification performance and nitrifying community in one full-scale membrane bioreactor (MBR) treating TFT-LCD wastewater. For the A/O MBR system treating monoethanolamine (MEA) and dimethyl sulfoxide (DMSO), no nitrification was observed, due presumably to high organic loading, high colloidal COD, low DO, and low hydraulic retention time (HRT) conditions. By including additional A/O or O/A tanks, the A/O/A/O MBR and the O/A/O MBR were able to perform successful nitrification. The real-time PCR results for quantification of nitrifying populations showed a high correlation to nitrification performance, and can be a good indicator of stable nitrification. Terminal restriction fragment length polymorphism (T-RFLP) results of functional gene, amoA, suggest that Nitrosomonas oligotropha-like AOB seemed to be important to a good nitrification in the MBR system. In the MBR system, Nitrobacter- and Nitrospira-like NOB were both abundant, but the low nitrite environment is likely to promote the growth of Nitrospira-like NOB. Copyright © 2012 Elsevier Ltd. All rights reserved.
DeWall, C. Nathan; Baumeister, Roy F.; Vohs, Kathleen D.
2008-01-01
Seven experiments showed that the effects of social acceptance and social exclusion on self-regulatory performance depend on the prospect of future acceptance. Excluded participants showed decrements in self-regulation, but these decrements were eliminated if the self-regulation task was ostensibly a diagnostic indicator of the ability to get along with others. No such improvement was found when the task was presented as diagnostic of good health. Accepted participants, in contrast, performed relatively poorly when the task was framed as a diagnostic indicator of interpersonally attractive traits. Furthermore, poor performance among accepted participants was not due to self-handicapping or overconfidence. Offering accepted participants a cash incentive for self-regulating eliminated the self-regulation deficits. These findings provide evidence that the need to belong fits standard motivational patterns: thwarting the drive intensifies it, whereas satiating it leads to temporary reduction in drive. Accepted people are normally good at self-regulation but are unwilling to exert the effort to self-regulate if self-regulation means gaining the social acceptance they have already obtained. PMID:19025289
Serban, D; Branescu, C; Savlovschi, C; Simion, G; Mihai, A; El-Khatib, A; Tudor, C; Nica, A; Vancea, G; Ghelase, M; Dascalu, A M
2016-01-01
The paper presents the case of a male patient, hospitalized for acute abdomen due to perforated callous ulcer. Though the clinical appearance suggested a benign pathology, the histopathological exam of the resection piece showed multicentric early gastric carcinoma, signet ring cell type. At the patient's request, total gastrectomy was not performed, a conservative solution being chosen instead. Superior digestive endoscopy with biopsy and oncological dispensarization was performed one month after surgery, then at every 6 months. After 2 years of benign results, the histopathological exam revealed the presence of malign singlet ring cells in the bioptic specimen. Respecting the patient's option of preserving a good quality of life, subtotal gastrectomy with Pean type gastroenteroanastomosis was performed followed by postoperatory chemotherapy. Endoscopic and oncological follow-up were performed at every six months for another 3 years (up to present), and the evolution was favorable with no local or metastatic recurrence. Histopathological examination was of great help in the surgical management of this case, allowing a fortunate early diagnosis, a conservative surgical approach, and the preserving of a good quality of life.
Improved MIMO radar GMTI via cyclic-shift transmission of orthogonal frequency division signals
NASA Astrophysics Data System (ADS)
Li, Fuyou; He, Feng; Dong, Zhen; Wu, Manqing
2018-05-01
Minimum detectable velocity (MDV) and maximum detectable velocity are both important in ground moving target indication (GMTI) systems. Smaller MDV can be achieved by longer baseline via multiple-input multiple-output (MIMO) radar. Maximum detectable velocity is decided by blind velocities associated with carrier frequencies, and blind velocities can be mitigated by orthogonal frequency division signals. However, the scattering echoes from different carrier frequencies are independent, which is not good for improving MDV performance. An improved cyclic-shift transmission is applied in MIMO GMTI system in this paper. MDV performance is improved due to the longer baseline, and maximum detectable velocity performance is improved due to the mitigation of blind velocities via multiple carrier frequencies. The signal model for this mode is established, the principle of mitigating blind velocities with orthogonal frequency division signals is presented; the performance of different MIMO GMTI waveforms is analysed; and the performance of different array configurations is analysed. Simulation results by space-time-frequency adaptive processing proves that our proposed method is a valid way to improve GMTI performance.
Analytical determination of propeller performance degradation due to ice accretion
NASA Technical Reports Server (NTRS)
Miller, T. L.
1986-01-01
A computer code has been developed which is capable of computing propeller performance for clean, glaze, or rime iced propeller configurations, thereby providing a mechanism for determining the degree of performance degradation which results from a given icing encounter. The inviscid, incompressible flow field at each specified propeller radial location is first computed using the Theodorsen transformation method of conformal mapping. A droplet trajectory computation then calculates droplet impingement points and airfoil collection efficiency for each radial location, at which point several user-selectable empirical correlations are available for determining the aerodynamic penalities which arise due to the ice accretion. Propeller performance is finally computed using strip analysis for either the clean or iced propeller. In the iced mode, the differential thrust and torque coefficient equations are modified by the drag and lift coefficient increments due to ice to obtain the appropriate iced values. Comparison with available experimental propeller icing data shows good agreement in several cases. The code's capability to properly predict iced thrust coefficient, power coefficient, and propeller efficiency is shown to be dependent on the choice of empirical correlation employed as well as proper specification of radial icing extent.
Comparing spatial regression to random forests for large ...
Environmental data may be “large” due to number of records, number of covariates, or both. Random forests has a reputation for good predictive performance when using many covariates, whereas spatial regression, when using reduced rank methods, has a reputation for good predictive performance when using many records. In this study, we compare these two techniques using a data set containing the macroinvertebrate multimetric index (MMI) at 1859 stream sites with over 200 landscape covariates. Our primary goal is predicting MMI at over 1.1 million perennial stream reaches across the USA. For spatial regression modeling, we develop two new methods to accommodate large data: (1) a procedure that estimates optimal Box-Cox transformations to linearize covariate relationships; and (2) a computationally efficient covariate selection routine that takes into account spatial autocorrelation. We show that our new methods lead to cross-validated performance similar to random forests, but that there is an advantage for spatial regression when quantifying the uncertainty of the predictions. Simulations are used to clarify advantages for each method. This research investigates different approaches for modeling and mapping national stream condition. We use MMI data from the EPA's National Rivers and Streams Assessment and predictors from StreamCat (Hill et al., 2015). Previous studies have focused on modeling the MMI condition classes (i.e., good, fair, and po
Semi-Supervised Recurrent Neural Network for Adverse Drug Reaction mention extraction.
Gupta, Shashank; Pawar, Sachin; Ramrakhiyani, Nitin; Palshikar, Girish Keshav; Varma, Vasudeva
2018-06-13
Social media is a useful platform to share health-related information due to its vast reach. This makes it a good candidate for public-health monitoring tasks, specifically for pharmacovigilance. We study the problem of extraction of Adverse-Drug-Reaction (ADR) mentions from social media, particularly from Twitter. Medical information extraction from social media is challenging, mainly due to short and highly informal nature of text, as compared to more technical and formal medical reports. Current methods in ADR mention extraction rely on supervised learning methods, which suffer from labeled data scarcity problem. The state-of-the-art method uses deep neural networks, specifically a class of Recurrent Neural Network (RNN) which is Long-Short-Term-Memory network (LSTM). Deep neural networks, due to their large number of free parameters rely heavily on large annotated corpora for learning the end task. But in the real-world, it is hard to get large labeled data, mainly due to the heavy cost associated with the manual annotation. To this end, we propose a novel semi-supervised learning based RNN model, which can leverage unlabeled data also present in abundance on social media. Through experiments we demonstrate the effectiveness of our method, achieving state-of-the-art performance in ADR mention extraction. In this study, we tackle the problem of labeled data scarcity for Adverse Drug Reaction mention extraction from social media and propose a novel semi-supervised learning based method which can leverage large unlabeled corpus available in abundance on the web. Through empirical study, we demonstrate that our proposed method outperforms fully supervised learning based baseline which relies on large manually annotated corpus for a good performance.
Quantum phase transition modulation in an atomtronic Mott switch
NASA Astrophysics Data System (ADS)
McLain, Marie A.; Carr, Lincoln D.
2018-07-01
Mott insulators provide stable quantum states and long coherence times due to small number fluctuations, making them good candidates for quantum memory and atomic circuits. We propose a proof-of-principle for a 1D Mott switch using an ultracold Bose gas and optical lattice. With time-evolving block decimation simulations—efficient matrix product state methods—we design a means for transient parameter characterization via a local excitation for ease of engineering into more complex atomtronics. We perform the switch operation by tuning the intensity of the optical lattice, and thus the interaction strength through a conductance transition due to the confined modifications of the ‘wedding cake’ Mott structure. We demonstrate the time-dependence of Fock state transmission and fidelity of the excitation as a means of tuning up the device in a double well and as a measure of noise performance. Two-point correlations via the g (2) measure provide additional information regarding superfluid fragments on the Mott insulating background due to the confinement of the potential.
2014-09-01
reasonable yield within this decade. Similarly, the permanent magnet motors , which are desirable for traction due to their high efficiency, must also be...degrees C and 180 degrees C (RDECOM Public Affairs 2014). Current electric drive vehicles, using permanent magnet motors , have thermal limitations well...performance and their good efficiency, benefits particularly applicable to permanent magnet motors . Synchronous motors with permanent magnets, in
Surgical Treatment of Snapping Scapula Syndrome Due to Malunion of Rib Fractures.
Ten Duis, Kaj; IJpma, Frank F A
2017-02-01
This report describes a case of snapping scapula syndrome (SSS) caused by malunited rib fractures. Abrasion of the deformed ribs was performed with good results. SSS as a cause of shoulder pain after thoracic trauma has to be considered and can be treated by a surgical abrasion technique. Copyright © 2017 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.
[Clinical studies on flomoxef in neonates].
Tabuki, K; Nishimura, T
1993-07-01
Clinical studies on flomoxef (FMOX) were performed in neonates and the results obtained are summarized as follows. Treatment with FMOX was made in 4 cases of neonatal bacterial infections; 2 cases of sepsis (suspected) and 1 case each of infection of umbilicus and staphylococcal scalded skin syndrome. Results obtained were excellent in 1 case, good in 3 cases. No significant side effects due to the drug were observed in any cases.
Implementation of 5S Method for Ergonomic Laboratory
NASA Astrophysics Data System (ADS)
Dila Sari, Amarria; Ilma Rahmillah, Fety; Prabowo Aji, Bagus
2017-06-01
This article discusses 5S implementation in Work System Design and Ergonomic Laboratory, Department of Industrial Engineering, Islamic University of Indonesia. There are some problems related to equipment settings for activity involving students such as files which is accumulated over the previous year practicum, as well as the movement of waste in the form of time due to the placement of goods that do not fit. Therefore, this study aims to apply the 5S method in DSK & E laboratory to facilitate the work processes and reduce waste. The project is performed by laboratory management using 5S methods in response to continuous improvement (Kaizen). Moreover, some strategy and suggestions are promoted to impose 5S system within the laboratory. As a result, the tidiness and cleanliness can be achieved that lead to the great performance of laboratory users. Score assessment before implementing 5S DSKE laboratory is at 64 (2.56) while the score after implementation is 32 (1.28) and shows an improvement of 50%. This has implications for better use in the laboratory area, save time when looking for tools and materials due to its location and good visual control, as well as improving the culture and spirit of ‘5S’ on staff regarding better working environment
NASA Astrophysics Data System (ADS)
Kong, Changduk; Lim, Semyeong; Kim, Keunwoo
2013-03-01
The Neural Networks is mostly used to engine fault diagnostic system due to its good learning performance, but it has a drawback due to low accuracy and long learning time to build learning data base. This work builds inversely a base performance model of a turboprop engine to be used for a high altitude operation UAV using measuring performance data, and proposes a fault diagnostic system using the base performance model and artificial intelligent methods such as Fuzzy and Neural Networks. Each real engine performance model, which is named as the base performance model that can simulate a new engine performance, is inversely made using its performance test data. Therefore the condition monitoring of each engine can be more precisely carried out through comparison with measuring performance data. The proposed diagnostic system identifies firstly the faulted components using Fuzzy Logic, and then quantifies faults of the identified components using Neural Networks leaned by fault learning data base obtained from the developed base performance model. In leaning the measuring performance data of the faulted components, the FFBP (Feed Forward Back Propagation) is used. In order to user's friendly purpose, the proposed diagnostic program is coded by the GUI type using MATLAB.
Verification of directed self-assembly (DSA) guide patterns through machine learning
NASA Astrophysics Data System (ADS)
Shim, Seongbo; Cai, Sibo; Yang, Jaewon; Yang, Seunghune; Choi, Byungil; Shin, Youngsoo
2015-03-01
Verification of full-chip DSA guide patterns (GPs) through simulations is not practical due to long runtime. We develop a decision function (or functions), which receives n geometry parameters of a GP as inputs and predicts whether the GP faithfully produces desired contacts (good) or not (bad). We take a few sample GPs to construct the function; DSA simulations are performed for each GP to decide whether it is good or bad, and the decision is marked in n-dimensional space. The hyper-plane that separates good marks and bad marks in that space is determined through machine learning process, and corresponds to our decision function. We try a single global function that can be applied to any GP types, and a series of functions in which each function is customized for different GP type; they are then compared and assessed in 10nm technology.
Nakao, Shigetomi; Hori, Takeshi; Miura, Kotaro; Tendo, Masashige; Nakata, Bunzo; Ishikawa, Tetsuro; Hirakawa, Kosei
2013-11-01
We report a case of a 60-year-old woman with abdominal distension who was treated with self-expandable metal stent (SEMS) placement in the proximal transverse colon. She was found to have severe bowel obstruction due to advanced transverse colon cancer on plain computed tomography (CT) and colonoscopy. We performed colonic stenting safely, and the symptom promptly improved. Defecation and flatus were observed on the same day of stenting, and the patient was able to start drinking and eating on the next day. Enhanced abdominal CT revealed multiple liver metastasis, peritoneal dissemination, ascites, and cystic ovarian tumor. After treatment with 1 course of 5-fluorouracil, Leucovorin, and oxaliplatin (mFOLFOX6), the patient was discharged on day 14 after admission. The rapidly enlarging ovarian tumors and primary colonic lesion with SEMS were surgically removed after treatment with mFOLFOX6 for 4 months in an outpatient basis. The patient has been alive with a good quality of life (QOL) and being treated with bevacizumab plus mFOLFOX6/Leucovorin, 5-fluorouracil, and irinotecan( FOLFIRI) for 6 months. SEMS placement could be safe and effective for the treatment of obstruction of the right colon, and could maintain a good QOL in patients.
Kazoora, H B; Majalija, S; Kiwanuka, N; Kaneene, J B
2016-12-01
A cross-sectional study involving multistage cluster sampling was undertaken in Kashari county, Mbarara district, western Uganda, in which quantitative and qualitative approaches were utilized to determine the knowledge, attitudes and practices regarding risk of human infection with zoonotic tuberculosis due to Mycobacterium bovis among cattle farmers. Of 496 respondents, 50% were farm owners and 50% herdsmen. Males were 70.9% of all the study participants. Among these, 37.5% had good knowledge, 41.4% had positive attitudes and 75.2% good practices regarding zoonotic tuberculosis. In the multivariable model, good knowledge was associated with having ever received health education, spending more than 5 years keeping cattle, having heard of cattle condemned at the abattoir due to tuberculosis and marital status. Positive attitudes were associated with having ever received health education, having heard of cattle condemned at the abattoir due to tuberculosis and being a farm owner versus being a herdsman. Good practices were associated with health education and good knowledge of the disease. Overall, knowledge and attitudes towards zoonotic tuberculosis due to M. bovis in humans was found to be low. While the majority of the respondents reported good practices, there were some still consuming raw milk and its products, which may predispose them to infection and indicates the need for greater outreach for zoonotic tuberculosis education. © 2016 Blackwell Verlag GmbH.
Electrospun Nanofiber-Coated Membrane Separators for Lithium-Ion Batteries
NASA Astrophysics Data System (ADS)
Lee, Hun
Lithium-ion batteries are widely used as a power source for portable electronic devices and hybrid electric vehicles due to their excellent energy and power densities, long cycle life, and enhanced safety. A separator is considered to be the critical component in lithium-ion rechargeable batteries. The separator is placed between the positive and negative electrodes in order to prevent the physical contact of electrodes while allowing the transportation of ions. In most commercial lithium-ion batteries, polyolefin microporous membranes are commonly used as the separator due to their good chemical stability and high mechanical strength. However, some of their intrinsic natures, such as low electrolyte uptake, poor adhesion property to the electrodes, and low ionic conductivity, can still be improved to achieve higher performance of lithium-ion batteries. In order to improve these intrinsic properties, polyolefin microporous membranes can be coated with nanofibers by using electrospinning technique. Electrospinning is a simple and efficient method to prepare nanofibers which can absorb a significant amount of liquid electrolyte to achieve low internal resistance and battery performance. This research presents the preparation and investigation of composite membrane separators prepared by coating nanofibers onto polyolefin microporous membranes via electrospinning technique. Polyvinylidene fluoride polymers and copolymers were used for the preparation of electrospun nanofiber coatings because they have excellent electrochemical stability, good adhesion property, and high temperature resistance. The nanofiber coatings prepared by electrospinning form an interconnected and randomly orientated structure on the surface of the polyolefin microporous membranes. The size of the nanofibers is on a scale that does not interfere with the micropores in the membrane substrates. The resultant nanofiber-coated membranes have the potential to combine advantages of both the polyolefin separator membranes and the nanoscale fibrous polymer coatings. The polyolefin microporous membranes serve as the supporting substrate which provides the required mechanical strength for the assembling process of lithium-ion batteries. The electrospun nanofiber coatings improve the wettability of the composite membrane separators to the liquid electrolyte, which is desirable for the lithium-ion batteries with high kinetics and good cycling performance. The results show that the nanofiber-coated membranes have enhanced adhesion properties to the battery electrode which can help prevent the formation of undesirable gaps between the separators and electrodes during prolonged charge-discharge cycles, especially in large-format batteries. The improvement on adhesive properties of nanofiber-coated membranes was evaluated by peel test. Nanofiber coatings applied to polyolefin membrane substrates improve the adhesion of separator membranes to battery electrodes. Electrolyte uptakes, ionic conductivities and interfacial resistances of the nanofiber-coated membrane separators were studied by soaking the membrane separators with a liquid electrolyte solution of 1 M lithium hexafluorophosphate dissolved in ethylene carbonate/dimethylcarbonate/ethylmethyl carbonate (1:1:1 vol). The nanofiber coatings on the surface of the membrane substrates increase the electrolyte uptake capacity due to the high surface area and capillary effect of nanofibers. The nanofiber-coated membranes soaked in the liquid electrolyte solution exhibit high ionic conductivities and low interfacial resistances to the lithium electrode. The cells containing LiFePO 4 cathode and the nanofiber-coated membranes as the separator show high discharge specific capacities and good cycling stability at room temperature. The nanofiber coatings on the membrane substrates contribute to high ionic conductivity and good electrochemical performance in lithium-ion batteries. Therefore, these nanofiber-coated composite membranes can be directly used as novel battery separators for high performance of lithium-ion batteries. Coating polyolefin microporous membranes with electrospun nanofibers is a promising approach to obtain highperformance separators for advanced lithium-ion batteries.
New Vectorial Propulsion System and Trajectory Control Designs for Improved AUV Mission Autonomy.
Masmitja, Ivan; Gonzalez, Julian; Galarza, Cesar; Gomariz, Spartacus; Aguzzi, Jacopo; Del Rio, Joaquin
2018-04-17
Autonomous Underwater Vehicles (AUV) are proving to be a promising platform design for multidisciplinary autonomous operability with a wide range of applications in marine ecology and geoscience. Here, two novel contributions towards increasing the autonomous navigation capability of a new AUV prototype (the Guanay II) as a mix between a propelled vehicle and a glider are presented. Firstly, a vectorial propulsion system has been designed to provide full vehicle maneuverability in both horizontal and vertical planes. Furthermore, two controllers have been designed, based on fuzzy controls, to provide the vehicle with autonomous navigation capabilities. Due to the decoupled system propriety, the controllers in the horizontal plane have been designed separately from the vertical plane. This class of non-linear controllers has been used to interpret linguistic laws into different zones of functionality. This method provided good performance, used as interpolation between different rules or linear controls. Both improvements have been validated through simulations and field tests, displaying good performance results. Finally, the conclusion of this work is that the Guanay II AUV has a solid controller to perform autonomous navigation and carry out vertical immersions.
NASA Technical Reports Server (NTRS)
August, Richard; Kaza, Krishna Rao V.
1988-01-01
An investigation of the vibration, performance, flutter, and forced response of the large-scale propfan, SR7L, and its aeroelastic model, SR7A, has been performed by applying available structural and aeroelastic analytical codes and then correlating measured and calculated results. Finite element models of the blades were used to obtain modal frequencies, displacements, stresses and strains. These values were then used in conjunction with a 3-D, unsteady, lifting surface aerodynamic theory for the subsequent aeroelastic analyses of the blades. The agreement between measured and calculated frequencies and mode shapes for both models is very good. Calculated power coefficients correlate well with those measured for low advance ratios. Flutter results show that both propfans are stable at their respective design points. There is also good agreement between calculated and measured blade vibratory strains due to excitation resulting from yawed flow for the SR7A propfan. The similarity of structural and aeroelastic results show that the SR7A propfan simulates the SR7L characteristics.
Intelligence related upper alpha desynchronization in a semantic memory task.
Doppelmayr, M; Klimesch, W; Hödlmoser, K; Sauseng, P; Gruber, W
2005-07-30
Recent evidence shows that event-related (upper) alpha desynchronization (ERD) is related to cognitive performance. Several studies observed a positive, some a negative relationship. The latter finding, interpreted in terms of the neural efficiency hypothesis, suggests that good performance is associated with a more 'efficient', smaller extent of cortical activation. Other studies found that ERD increases with semantic processing demands and that this increase is larger for good performers. Studies supporting the neural efficiency hypothesis used tasks that do not specifically require semantic processing. Thus, we assume that the lack of semantic processing demands may at least in part be responsible for the reduced ERD. In the present study we measured ERD during a difficult verbal-semantic task. The findings demonstrate that during semantic processing, more intelligent (as compared to less intelligent) subjects exhibited a significantly larger upper alpha ERD over the left hemisphere. We conclude that more intelligent subjects exhibit a more extensive activation in a semantic processing system and suggest that divergent findings regarding the neural efficiency hypotheses are due to task specific differences in semantic processing demands.
Saleem, Muhammad; Yu, Haojie; Wang, Li; Zain-ul-Abdin; Khalid, Hamad; Akram, M; Abbasi, Nasir M; Huang, Jin
2015-05-30
The interest in glucose biosensors persisted over many years and persistent efforts have been made to develop long term stable glucose biosensors with precision, smart analytical performance, good linearity and resistance to communal interferences. In this regard, ferrocene-based polymers and derivatives (FBPDs) for the development of glucose biosensor (GBs) as redox mediators have acquired utmost attention of the scientists, especially in the second generation biosensors, as a large number of innovative molecules have been synthesized. Most of the FBPDs are considered as active components in the development of GBs, due to their ease of modification, biocompatibility, stability, large surface area, good electrical conductivity and especially excellent redox properties. This review provides a brief description of synthesis, analytical performance and glucose sensing application of ferrocene-based dendrimers, polythiophenes, polypyrroles, polyethylenimine, chitosan and carbon nano tubes (CNTs). Moreover, the analytical performance of ferrocene-based glucose biosensors (FBGBs) is summarized and the problems associated with the construction of GBs and the future trends are discussed. Copyright © 2015 Elsevier B.V. All rights reserved.
The ATLAS tile calorimeter performance at the LHC
DOE Office of Scientific and Technical Information (OSTI.GOV)
Calkins, R.
The Tile Calorimeter (TileCal), the central section of the hadronic calorimeter of the ATLAS experiment, is a key detector component to detect hadrons, jets and taus and to measure the missing transverse energy. Due to the very good muon signal to noise ratio it assists the spectrometer in the identification and reconstruction of muons. TileCal is built of steel and scintillating tiles coupled to optical fibers and read out by photomultipliers. The calorimeter is equipped with systems that allow to monitor and to calibrate each stage of the read out system exploiting different signal sources: laser light, charge injection andmore » a radioactive source. The performance of the calorimeter has been measured and monitored using calibration data, random triggered data, cosmic muons and more importantly LHC collision events. The results presented here assess the absolute energy scale calibration precision, the energy and timing uniformity and the synchronization precision. The ensemble of the results demonstrates a very good understanding of the performance of the Tile Calorimeter that is proved to be well within the design expectations. (authors)« less
Development of Pelton turbine using numerical simulation
NASA Astrophysics Data System (ADS)
Patel, K.; Patel, B.; Yadav, M.; Foggia, T.
2010-08-01
This paper describes recent research and development activities in the field of Pelton turbine design. Flow inside Pelton turbine is most complex due to multiphase (mixture of air and water) and free surface in nature. Numerical calculation is useful to understand flow physics as well as effect of geometry on flow. The optimized design is obtained using in-house special optimization loop. Either single phase or two phase unsteady numerical calculation could be performed. Numerical results are used to visualize the flow pattern in the water passage and to predict performance of Pelton turbine at full load as well as at part load. Model tests are conducted to determine performance of turbine and it shows good agreement with numerically predicted performance.
[Series: Medical Applications of the PHITS Code (2): Acceleration by Parallel Computing].
Furuta, Takuya; Sato, Tatsuhiko
2015-01-01
Time-consuming Monte Carlo dose calculation becomes feasible owing to the development of computer technology. However, the recent development is due to emergence of the multi-core high performance computers. Therefore, parallel computing becomes a key to achieve good performance of software programs. A Monte Carlo simulation code PHITS contains two parallel computing functions, the distributed-memory parallelization using protocols of message passing interface (MPI) and the shared-memory parallelization using open multi-processing (OpenMP) directives. Users can choose the two functions according to their needs. This paper gives the explanation of the two functions with their advantages and disadvantages. Some test applications are also provided to show their performance using a typical multi-core high performance workstation.
Imaging through strong turbulence with a light field approach.
Wu, Chensheng; Ko, Jonathan; Davis, Christopher C
2016-05-30
Under strong turbulence conditions, object's images can be severely distorted and become unrecognizable throughout the observing time. Conventional image restoring algorithms do not perform effectively in these circumstances due to the loss of good references on the object. We propose the use a plenoptic sensor as a light field camera to map a conventional camera image onto a cell image array in the image's sub-angular spaces. Accordingly, each cell image on the plenoptic sensor is equivalent to the image acquired by a sub-aperture of the imaging lens. The wavefront distortion over the lens aperture can be analyzed by comparing cell images in the plenoptic sensor. By using a modified "Laplacian" metric, we can identify a good cell image in a plenoptic image sequence. The good cell image corresponds with the time and sub-aperture area on the imaging lens where wavefront distortion becomes relatively and momentarily "flat". As a result, it will reveal the fundamental truths of the object that would be severely distorted on normal cameras. In this paper, we will introduce the underlying physics principles and mechanisms of our approach and experimentally demonstrate its effectiveness under strong turbulence conditions. In application, our approach can be used to provide a good reference for conventional image restoring approaches under strong turbulence conditions. This approach can also be used as an independent device to perform object recognition tasks through severe turbulence distortions.
Performance of Several Density Functional Theory Methods on Describing Hydrogen-Bond Interactions.
Rao, Li; Ke, Hongwei; Fu, Gang; Xu, Xin; Yan, Yijing
2009-01-13
We have investigated eleven density functionals, including LDA, PBE, mPWPW91, TPSS, B3LYP, X3LYP, PBE0, O3LYP, B97-1, MPW1K, and TPSSh, for their performances on describing hydrogen bond (HB) interactions. The emphasis has been laid not only on their abilities to calculate the intermolecular hydrogen bonding energies but also on their performances in predicting the relative energies of intermolecular H-bonded complexes and the conformer stabilities due to intramolecular hydrogen bondings. As compared to the best theoretical values, we found that although PBE and PBE0 gave the best estimation of HB strengths, they might fail to predict the correct order of relative HB energies, which might lead to a wrong prediction of the global minimum for different conformers. TPSS and TPSSh did not always improve over PBE and PBE0. B3LYP was found to underestimate the intermolecular HB strengths but was among the best performers in calculating the relative HB energies. We showed here that X3LYP and B97-1 were able to give good values for both absolute HB strengths and relative HB energies, making these functionals good candidates for HB description.
Antegrade Ureteral Stenting is a Good Alternative for the Retrograde Approach.
van der Meer, Rutger W; Weltings, Saskia; van Erkel, Arian R; Roshani, Hossain; Elzevier, Henk W; van Dijk, Lukas C; van Overhagen, Hans
2017-07-01
Double J (JJ) stents for treating obstructive ureteral pathology are generally inserted through a retrograde route with cystoscopic guidance. Antegrade percutaneous insertion using fluoroscopy can be performed alternatively but is less known. Indications, success rate and complications of antegrade ureteral stenting were evaluated. Data of consecutive patients in which antegrade ureteral stenting was performed were retrospectively analysed using the radiology information system and patient records. Patient characteristics, details of the antegrade JJ stent insertion procedure and registered complications were collected. Furthermore, it was investigated if prior to the antegrade procedure a retrograde attempt for JJ stent insertion was performed. Total 130 attempts for antegrade JJ stent insertion were performed in 100 patients. A percutaneous nephrostomy catheter had already been placed in the majority of kidneys (n = 109) for initial treatment of hydronephrosis. Most prevelant indication for a JJ stent was obstructive ureteral pathology due to malignancy (n = 63). A JJ stent was successfully inserted in 125 of 130 procedures. In 21 cases, previous retrograde ureteral stenting had failed but, subsequent antegrade ureteral stenting was successful. There were 8 procedure related complications; 6 infections, 1 false tract and 1 malposition. Antegrade percutaneous insertion of a JJ stent is a good alternative for retrograde insertion.
End-of-life of starch-polyvinyl alcohol biopolymers.
Guo, M; Stuckey, D C; Murphy, R J
2013-01-01
This study presents a life cycle assessment (LCA) model comparing the waste management options for starch-polyvinyl alcohol (PVOH) biopolymers including landfill, anaerobic digestion (AD), industrial composting and home composting. The ranking of biological treatment routes for starch-PVOH biopolymer wastes depended on their chemical compositions. AD represents the optimum choice for starch-PVOH biopolymer containing N and S elements in global warming potential (GWP(100)), acidification and eutrophication but not on the remaining impact categories, where home composting was shown to be a better option due to its low energy and resource inputs. For those starch-PVOH biopolymers with zero N and S contents home composting delivered the best environmental performance amongst biological treatment routes in most impact categories (except for GWP(100)). The landfill scenario performed generally well due largely to the 100-year time horizon and efficient energy recovery system modeled but this good performance is highly sensitive to assumptions adopted in landfill model. Copyright © 2012 Elsevier Ltd. All rights reserved.
Radar HRRP Target Recognition Based on Stacked Autoencoder and Extreme Learning Machine
Liu, Yongxiang; Huo, Kai; Zhang, Zhongshuai
2018-01-01
A novel radar high-resolution range profile (HRRP) target recognition method based on a stacked autoencoder (SAE) and extreme learning machine (ELM) is presented in this paper. As a key component of deep structure, the SAE does not only learn features by making use of data, it also obtains feature expressions at different levels of data. However, with the deep structure, it is hard to achieve good generalization performance with a fast learning speed. ELM, as a new learning algorithm for single hidden layer feedforward neural networks (SLFNs), has attracted great interest from various fields for its fast learning speed and good generalization performance. However, ELM needs more hidden nodes than conventional tuning-based learning algorithms due to the random set of input weights and hidden biases. In addition, the existing ELM methods cannot utilize the class information of targets well. To solve this problem, a regularized ELM method based on the class information of the target is proposed. In this paper, SAE and the regularized ELM are combined to make full use of their advantages and make up for each of their shortcomings. The effectiveness of the proposed method is demonstrated by experiments with measured radar HRRP data. The experimental results show that the proposed method can achieve good performance in the two aspects of real-time and accuracy, especially when only a few training samples are available. PMID:29320453
Radar HRRP Target Recognition Based on Stacked Autoencoder and Extreme Learning Machine.
Zhao, Feixiang; Liu, Yongxiang; Huo, Kai; Zhang, Shuanghui; Zhang, Zhongshuai
2018-01-10
A novel radar high-resolution range profile (HRRP) target recognition method based on a stacked autoencoder (SAE) and extreme learning machine (ELM) is presented in this paper. As a key component of deep structure, the SAE does not only learn features by making use of data, it also obtains feature expressions at different levels of data. However, with the deep structure, it is hard to achieve good generalization performance with a fast learning speed. ELM, as a new learning algorithm for single hidden layer feedforward neural networks (SLFNs), has attracted great interest from various fields for its fast learning speed and good generalization performance. However, ELM needs more hidden nodes than conventional tuning-based learning algorithms due to the random set of input weights and hidden biases. In addition, the existing ELM methods cannot utilize the class information of targets well. To solve this problem, a regularized ELM method based on the class information of the target is proposed. In this paper, SAE and the regularized ELM are combined to make full use of their advantages and make up for each of their shortcomings. The effectiveness of the proposed method is demonstrated by experiments with measured radar HRRP data. The experimental results show that the proposed method can achieve good performance in the two aspects of real-time and accuracy, especially when only a few training samples are available.
Performance Evaluation System Update: Choosing the Right Force for an Austere Future
2013-04-23
decided to grow from 192,000 active duty Marines to 202,000 due to increased operational demands of the wars.1 Then last year, the Marine Corps...involved with off duty activities as long as it helps them get promoted. Ideally, encouraging more positive interactions between Marines and civilians...situations. However, the Marine Corps has not traditionally done as good a job encouraging its Marines to pursue relevant extracurricular education. Like
Low-Cost High-Precision PIAA Optics for High Contrast Imaging with Exo-Planet Coronagraphs
NASA Technical Reports Server (NTRS)
Balasubramanian, Kunjithapatham; Shaklan, Stuart B.; Pueyo, Laurent; Wilson, Daniel W.; Guyon, Olivier
2010-01-01
PIAA optics for high contrast imaging present challenges in manufacturing and testing due to their large surface departures from aspheric profiles at the aperture edges. With smaller form factors and consequent smaller surface deformations (<50 microns), fabrication of these mirrors with diamond turning followed by electron beam lithographic techniques becomes feasible. Though such a design reduces the system throughput to approx.50%, it still provides good performance down to 2 lambda/D inner working angle. With new achromatic focal plane mask designs, the system performance can be further improved. We report on the design, expected performance, fabrication challenges, and initial assessment of such novel PIAA optics.
Application of an efficient hybrid scheme for aeroelastic analysis of advanced propellers
NASA Technical Reports Server (NTRS)
Srivastava, R.; Sankar, N. L.; Reddy, T. S. R.; Huff, D. L.
1989-01-01
An efficient 3-D hybrid scheme is applied for solving Euler equations to analyze advanced propellers. The scheme treats the spanwise direction semi-explicitly and the other two directions implicitly, without affecting the accuracy, as compared to a fully implicit scheme. This leads to a reduction in computer time and memory requirement. The calculated power coefficients for two advanced propellers, SR3 and SR7L, and various advanced ratios showed good correlation with experiment. Spanwise distribution of elemental power coefficient and steady pressure coefficient differences also showed good agreement with experiment. A study of the effect of structural flexibility on the performance of the advanced propellers showed that structural deformation due to centrifugal and aero loading should be included for better correlation.
Character context: a shape descriptor for Arabic handwriting recognition
NASA Astrophysics Data System (ADS)
Mudhsh, Mohammed; Almodfer, Rolla; Duan, Pengfei; Xiong, Shengwu
2017-11-01
In the handwriting recognition field, designing good descriptors are substantial to obtain rich information of the data. However, the handwriting recognition research of a good descriptor is still an open issue due to unlimited variation in human handwriting. We introduce a "character context descriptor" that efficiently dealt with the structural characteristics of Arabic handwritten characters. First, the character image is smoothed and normalized, then the character context descriptor of 32 feature bins is built based on the proposed "distance function." Finally, a multilayer perceptron with regularization is used as a classifier. On experimentation with a handwritten Arabic characters database, the proposed method achieved a state-of-the-art performance with recognition rate equal to 98.93% and 99.06% for the 66 and 24 classes, respectively.
Wiszniewska, Marta; Tymoszuk, Diana; Lipińska-Ojrzanowska, Agnieszka; Wagrowska-Koski, Ewa; Walusiak-Skorupa, Jolanta
2013-01-01
Respiratory diseases are a cause of long-term sickness absence, and even of partial or complete inability to work. This paper presents the first in Poland description of principles of good practice in occupational health service provided for people with respiratory diseases. The issues concerning the certification of the ability to work in this group of patients are discussed. The key-principles of preventive care of workers with obstructive and interstitial lung diseases with particular attention paid to the control of major risk factors are also presented. The importance of possible contraindications for job performance by workers affected by these diseases, as well as the responsibilities of occupational health physicians were highlighted. M
Local dynamic subgrid-scale models in channel flow
NASA Technical Reports Server (NTRS)
Cabot, William H.
1994-01-01
The dynamic subgrid-scale (SGS) model has given good results in the large-eddy simulation (LES) of homogeneous isotropic or shear flow, and in the LES of channel flow, using averaging in two or three homogeneous directions (the DA model). In order to simulate flows in general, complex geometries (with few or no homogeneous directions), the dynamic SGS model needs to be applied at a local level in a numerically stable way. Channel flow, which is inhomogeneous and wall-bounded flow in only one direction, provides a good initial test for local SGS models. Tests of the dynamic localization model were performed previously in channel flow using a pseudospectral code and good results were obtained. Numerical instability due to persistently negative eddy viscosity was avoided by either constraining the eddy viscosity to be positive or by limiting the time that eddy viscosities could remain negative by co-evolving the SGS kinetic energy (the DLk model). The DLk model, however, was too expensive to run in the pseudospectral code due to a large near-wall term in the auxiliary SGS kinetic energy (k) equation. One objective was then to implement the DLk model in a second-order central finite difference channel code, in which the auxiliary k equation could be integrated implicitly in time at great reduction in cost, and to assess its performance in comparison with the plane-averaged dynamic model or with no model at all, and with direct numerical simulation (DNS) and/or experimental data. Other local dynamic SGS models have been proposed recently, e.g., constrained dynamic models with random backscatter, and with eddy viscosity terms that are averaged in time over material path lines rather than in space. Another objective was to incorporate and test these models in channel flow.
Discriminative segmentation of microscopic cellular images.
Cheng, Li; Ye, Ning; Yu, Weimiao; Cheah, Andre
2011-01-01
Microscopic cellular images segmentation has become an important routine procedure in modern biological research, due to the rapid advancement of fluorescence probes and robotic microscopes in recent years. In this paper we advocate a discriminative learning approach for cellular image segmentation. In particular, three new features are proposed to capture the appearance, shape and context information, respectively. Experiments are conducted on three different cellular image datasets. Despite the significant disparity among these datasets, the proposed approach is demonstrated to perform reasonably well. As expected, for a particular dataset, some features turn out to be more suitable than others. Interestingly, we observe that a further gain can often be obtained on top of using the "good" features, by also retaining those features that perform poorly. This might be due to the complementary nature of these features, as well as the capacity of our approach to better integrate and exploit different sources of information.
[Replantation at lower leg level].
Daigeler, A; Fansa, H; Westphal, T; Schneider, W
2003-11-01
Replantation in reconstructive surgery is an established procedure due to microsurgical techniques. It can be routinely performed in unilateral lower leg amputation. In some cases of bilateral amputation, in which orthotopic replantation is not possible due to the complex trauma, heterotopic replantation is a therapeutic option. This avoids prosthetic fitting. We report five cases of orthotopic and two of heterotopic lower limb replantations. Functional outcome concerning sensibility, mobility, pain, and aesthetic result were assessed clinically and using a questionnaire. Functional outcome and patient satisfaction were good. The psychological situation of the patients as well as mobility and stability of the replanted limbs were satisfying. Heterotopically replanted patients found the replanted legs superior to the prostheses. We conclude that, in lower leg amputation, attempts should be made to replant the extremity. In bilateral lower leg amputations, at least one limb should be reconstructed, even if "only" a heterotopic replantation can be performed.
Aerodynamic Performance of an Active Flow Control Configuration Using Unstructured-Grid RANS
NASA Technical Reports Server (NTRS)
Joslin, Ronald D.; Viken, Sally A.
2001-01-01
This research is focused on assessing the value of the Reynolds-Averaged Navier-Stokes (RANS) methodology for active flow control applications. An experimental flow control database exists for a TAU0015 airfoil, which is a modification of a NACA0015 airfoil. The airfoil has discontinuities at the leading edge due to the implementation of a fluidic actuator and aft of mid chord on the upper surface. This paper documents two- and three-dimensional computational results for the baseline wing configuration (no control) with tile experimental results. The two-dimensional results suggest that the mid-chord discontinuity does not effect the aerodynamics of the wing and can be ignored for more efficient computations. The leading-edge discontinuity significantly affects tile lift and drag; hence, the integrity of the leading-edge notch discontinuity must be maintained in the computations to achieve a good match with the experimental data. The three-dimensional integrated performance results are in good agreement with the experiments inspite of some convergence and grid resolution issues.
Improved performance of graphene transistors by strain engineering.
Nguyen, V Hung; Nguyen, Huy-Viet; Dollfus, P
2014-04-25
By means of numerical simulation, in this work we study the effects of uniaxial strain on the transport properties of strained graphene heterojunctions and explore the possibility of achieving good performance of graphene transistors using these hetero-channels. It is shown that a finite conduction gap can open in the strain junctions due to strain-induced deformation of the graphene bandstructure. These hetero-channels are then demonstrated to significantly improve the operation of graphene field-effect transistors (FETs). In particular, the ON/OFF current ratio can reach a value of over 10(5). In graphene normal FETs, the transconductance, although reduced compared to the case of unstrained devices, is still high, while good saturation of current can be obtained. This results in a high voltage gain and a high transition frequency of a few hundreds of GHz for a gate length of 80 nm. In graphene tunneling FETs, subthreshold swings lower than 30 mV /dec, strong nonlinear effects such as gate-controllable negative differential conductance, and current rectification are observed.
Sisco, Howard; Leventhal, Gloria
2007-12-01
The importance of accurate performance appraisals is central to many aspects of personnel activities in organizations. This study examined threats due to past performance to accuracy of evaluation of subsequent performance by raters differing in scores on field dependence. 162 college students were classified as Field-dependent (n = 81) or Field-independent (n = 81), using a median split on the Group Embedded Figures Test. Past performance (a lecture) was good or poor, presented directly via a videotape or indirectly via a written evaluation to the Field-independent or Field-dependent groups. Analysis indicated the hypothesized contrast effect (ratings in the opposite direction from that of prior ratings) in the Direct condition and an unexpected, albeit smaller, contrast effect in the Indirect condition. There were also differential effects of performance, presentation, and field dependency on rating of lecturer's style and ability.
NASA Astrophysics Data System (ADS)
Chye, Matthew B.
2011-12-01
Batteries and asymmetric electrochemical capacitors using nickel-based positive electrodes can provide high currents due to their defect structure and low internal resistance. Nickel-based positive electrodes, therefore, are ideal for high current applications such as power tools and electric vehicles (EVs). The positive electrodes prepared in this research are monolithic graphitic foams electrochemically impregnated with nickel oxyhydroxide active mass and select additives that enhance electrode performance. Carbon foam is a good current collector due to its light-weight, porous, and graphitic nature, which give its good electrical properties and the ability to be used as a current collector. Replacing sintered nickel current collectors in nickel-based batteries with a low cost, readily available material, carbon foam, can reduce the mass of a rechargeable battery. The goal of this research has been to contribute to fundamental science through better understanding of optimizing the deposition and formation processes of the active mass onto carbon foams as well as investigating the active mass behavior under deposition, formation, and cycling conditions. Flooded cells and a PFA sealed asymmetric capacitor have been used. The effects of carbon foam surface pretreatments and how they affect the active material/carbon foam performance are demonstrated. Also the feasibility of this positive electrode as a component in nickel-based batteries, a Ni-Zn cells and an asymmetric capacitor pouch cell, is demonstrated.
A Capacity Forecast Model for Volatile Data in Maintenance Logistics
NASA Astrophysics Data System (ADS)
Berkholz, Daniel
2009-05-01
Maintenance, repair and overhaul processes (MRO processes) are elaborate and complex. Rising demands on these after sales services require reliable production planning and control methods particularly for maintaining valuable capital goods. Downtimes lead to high costs and an inability to meet delivery due dates results in severe contract penalties. Predicting the required capacities for maintenance orders in advance is often difficult due to unknown part conditions unless the goods are actually inspected. This planning uncertainty results in extensive capital tie-up by rising stock levels within the whole MRO network. The article outlines an approach to planning capacities when maintenance data forecasting is volatile. It focuses on the development of prerequisites for a reliable capacity planning model. This enables a quick response to maintenance orders by employing appropriate measures. The information gained through the model is then systematically applied to forecast both personnel capacities and the demand for spare parts. The improved planning reliability can support MRO service providers in shortening delivery times and reducing stock levels in order to enhance the performance of their maintenance logistics.
Preliminary Experiments for the Assessment of V/W-band Links for Space-Earth Communications
NASA Technical Reports Server (NTRS)
Nessel, James A.; Acosta, Roberto J.; Miranda, Felix A.
2013-01-01
Since September 2012, NASA Glenn Research Center has deployed a microwave profiling radiometer at White Sands, NM, to estimate atmospheric propagation effects on communications links in the V and W bands (71-86GHz). Estimates of attenuation statistics in the millimeter wave due to gaseous and cloud components of the atmosphere show good agreement with current ITU-R models, but fail to predict link performance in the presence of moderate to heavy rain rates, due to the inherent limitations of passive radiometry. Herein, we discuss the preliminary results of these measurements and describe a design for a terrestrial link experiment to validate/refine existing rain attenuation models in the V/Wbands.
Preliminary Experiments for the Assessment of VW-Band Links for Space-Earth Communications
NASA Technical Reports Server (NTRS)
Nessel, James A.; Acosta, Roberto J.; Miranda, Felix A.
2013-01-01
Since September 2012, NASA Glenn Research Center has deployed a microwave profiling radiometer at White Sands, NM, to estimate atmospheric propagation effects on communications links in the V and W bands (71-86GHz). Estimates of attenuation statistics in the millimeter wave due to gaseous and cloud components of the atmosphere show good agreement with current ITU-R models, but fail to predict link performance in the presence of moderate to heavy rain rates, due to the inherent limitations of passive radiometry. Herein, we discuss the preliminary results of these measurements and describe a design for a terrestrial link experiment to validaterefine existing rain attenuation models in the VW-bands.
A side-by-side comparison of CPV module and system performance
DOE Office of Scientific and Technical Information (OSTI.GOV)
Muller, Matthew; Marion, Bill; Kurtz, Sarah
A side-by-side comparison is made between concentrator photovoltaic module and system direct current aperture efficiency data with a focus on quantifying system performance losses. The individual losses measured/calculated, when combined, are in good agreement with the total loss seen between the module and the system. Results indicate that for the given test period, the largest individual loss of 3.7% relative is due to the baseline performance difference between the individual module and the average for the 200 modules in the system. A basic empirical model is derived based on module spectral performance data and the tabulated losses between the modulemore » and the system. The model predicts instantaneous system direct current aperture efficiency with a root mean square error of 2.3% relative.« less
Sharma, Greeshma; Gramann, Klaus; Chandra, Sushil; Singh, Vijander; Mittal, Alok Prakash
2017-09-01
Emerging evidence suggests that the variations in the ability to navigate through any real or virtual environment are accompanied by distinct underlying cortical activations in multiple regions of the brain. These activations may appear due to the use of different frame of reference (FOR) for representing an environment. The present study investigated the brain dynamics in the good and bad navigators using Graph Theoretical analysis applied to low-density electroencephalography (EEG) data. Individual navigation skills were rated according to the performance in a virtual reality (VR)-based navigation task and the effect of navigator's proclivity towards a particular FOR on the navigation performance was explored. Participants were introduced to a novel virtual environment that they learned from a first-person or an aerial perspective and were subsequently assessed on the basis of efficiency with which they learnt and recalled. The graph theoretical parameters, path length (PL), global efficiency (GE), and clustering coefficient (CC) were computed for the functional connectivity network in the theta and alpha frequency bands. During acquisition of the spatial information, good navigators were distinguished by a lower degree of dispersion in the functional connectivity compared to the bad navigators. Within the groups of good and bad navigators, better performers were characterised by the formation of multiple hubs at various sites and the percentage of connectivity or small world index. The proclivity towards a specific FOR during exploration of a new environment was not found to have any bearing on the spatial learning. These findings may have wider implications for how the functional connectivity in the good and bad navigators differs during spatial information acquisition and retrieval in the domains of rescue operations and defence systems.
Enhancement of SPES source performances.
Fagotti, E; Palmieri, A; Ren, X
2008-02-01
Installation of SPES source at LNL was finished in July 2006 and the first beam was extracted in September 2006. Commissioning results confirmed very good performance of the extracted current density. Conversely, source reliability was very poor due to glow-discharge phenomena, which were caused by the ion source axial magnetic field protruding in the high-voltage column. This problem was fixed by changing the stainless steel plasma electrode support with a ferromagnetic one. This new configuration required us to recalculate ion source solenoids positions and fields in order to recover the correct resonance pattern. Details on magnetic simulations and experimental results of high voltage column shielding are presented.
Scalable nuclear density functional theory with Sky3D
NASA Astrophysics Data System (ADS)
Afibuzzaman, Md; Schuetrumpf, Bastian; Aktulga, Hasan Metin
2018-02-01
In nuclear astrophysics, quantum simulations of large inhomogeneous dense systems as they appear in the crusts of neutron stars present big challenges. The number of particles in a simulation with periodic boundary conditions is strongly limited due to the immense computational cost of the quantum methods. In this paper, we describe techniques for an efficient and scalable parallel implementation of Sky3D, a nuclear density functional theory solver that operates on an equidistant grid. Presented techniques allow Sky3D to achieve good scaling and high performance on a large number of cores, as demonstrated through detailed performance analysis on a Cray XC40 supercomputer.
Study of the performance of the infrasound Station IS48TN during the period 2011 -2017
NASA Astrophysics Data System (ADS)
Mejri, Chourouk
2017-04-01
The Infrasound Station IS48, in Kesra, Tunisia is part of the verification regime for the Comprehensive Nuclear-Test-Ban Treaty. IS48 is managed and maintained by the Tunisian NDC. Its good location in the middle of the Mediterranean Sea allows to have various and interesting detections. Several events were recorded and identified. But since 2010, the performance of the station has began to be noisy , due to a leakage in the pipe array, despite efforts to solve the issue through the pressure test and maintenance . To this issues, PTS decided to upgrade the WNRS at IS48TN.
Constraints on Smoke Injection Height, Source Strength, and Transports from MISR and MODIS
NASA Technical Reports Server (NTRS)
Kahn, Ralph A.; Petrenko, Mariya; Val Martin, Maria; Chin, Mian
2014-01-01
The AeroCom BB (Biomass Burning) Experiment AOD (Aerosol Optical Depth) motivation: We have a substantial set of satellite wildfire plume AOD snapshots and injection heights to help calibrate model/inventory performance; We are 1) adding more fire source-strength cases 2) using MISR to improve the AOD constrains and 3) adding 2008 global injection heights; We selected GFED3-daily due to good overall source strength performance, but any inventory can be tested; Joint effort to test multiple, global models, to draw robust BB injection height and emission strength conclusions. We provide satellite-based injection height and smoke plume AOD climatologies.
Effectiveness and biological compatibility of different generations of dentin adhesives.
da Silva, João M F; Rodrigues, José R; Camargo, Carlos H R; Fernandes, Virgilio Vilas Boas; Hiller, Karl-Anton; Schweikl, Helmut; Schmalz, Gottfried
2014-01-01
Besides possessing good mechanical properties, dental materials should present a good biological behavior and should not injure the involved tissues. Bond strength and biocompatibility are both highly significant properties of dentin adhesives. For that matter, these properties of four generations of adhesive systems (Multi-Purpose/Single Bond/SE Plus/Easy Bond) were evaluated. Eighty bovine teeth had their dentin exposed (500- and 200-μm thickness). Adhesive was applied on the dentin layer of each specimen. Following that, the microshearing test was performed for all samples. A dentin barrier test was used for the cytotoxicity evaluation. Cell cultures (SV3NeoB) were collected from testing materials by means of 200- or 500-μm-thick dentin slices and placed in a cell culture perfusion chamber. Cell viability was measured 24 h post-exposition by means of a photometrical test (MTT test). The best bonding performance was shown by the single-step adhesive Easy Bond (21 MPa, 200 μm; 27 MPa, 500 μm) followed by Single Bond (15.6 MPa, 200 μm; 23.4 MPa, 500 μm), SE Plus (18.2 MPa, 200 μm; 20 MPa, 500 μm), and Multi-Purpose (15.2 MPa, 200 μm; 17.9 MPa, 500 μm). Regarding the cytotoxicity, Multi-Purpose slightly reduced the cell viability to 92% (200 μm)/93% (500 μm). Single Bond was reasonably cytotoxic, reducing cell viability to 71% (200 μm)/64% (500 μm). The self-etching adhesive Scotchbond SE decreased cell viability to 85% (200 μm)/71% (500 μm). Conversely, Easy Bond did not reduce cell viability in this test, regardless of the dentin thickness. Results showed that the one-step system had the best bond strength performance and was the least toxic to pulp cells. In multiple-step systems, a correct bonding technique must be done, and a pulp capping strategy is necessary for achieving good performance in both properties. The study showed a promising system (one-step self-etching), referring to it as a good alternative for specific cases, mainly due to its technical simplicity and good biological responses.
A case of Sotos syndrome treated with distraction osteogenesis in maxilla and mandible.
Takano, Masayuki; Kasahara, Kiyohiro; Ogawa, Chiharu; Katada, Hidenori; Sueishi, Kenji
2012-01-01
Sotos syndrome is inherited in an autosomal-dominant manner and is characterized by increased birth weight, excessive growth, advanced bone age, and distinctive facial features, including dolichocephaly, hypertelorism, and a prominent mandible. We treated a jaw deformity due to Sotos syndrome consisting of malocclusion due to a narrow maxillary dental arch and mandibular retrusion from hypoplasia of the rami. The patient was a 17-year-old man. Malocclusion due to a narrow maxillary dental arch and mandibular retrusion was diagnosed. Rapid maxillary expansion with Lines corticotomy and mandibular advancement with distraction osteogenesis were performed. The maxilla was expanded laterally a total of 3 mm and the mandible prolonged 12 mm in the posterior area of the mandibular body. Subsequently, orthodontic treatment was continued. At present, 5 years after surgery, occlusion remains good and stable.
Determining team cognition from delay analysis using cross recurrence plot.
Hajari, Nasim; Cheng, Irene; Bin Zheng; Basu, Anup
2016-08-01
Team cognition is an important factor in evaluating and determining team performance. Forming a team with good shared cognition is even more crucial for laparoscopic surgery applications. In this study, we analyzed the eye tracking data of two surgeons during a laparoscopic simulation operation, then performed Cross Recurrence Analysis (CRA) on the recorded data to study the delay behaviour for good performer and poor performer teams. Dual eye tracking data for twenty two dyad teams were recorded during a laparoscopic task and then the teams were divided into good performer and poor performer teams based on the task times. Eventually we studied the delay between two team members for good and poor performer teams. The results indicated that the good performer teams show a smaller delay comparing to poor performer teams. This study is compatible with gaze overlap analysis between team members and therefore it is a good evidence of shared cognition between team members.
ERIC Educational Resources Information Center
Uerling, Donald F.; Strope, John L., Jr.
The purpose of this paper is to explore the due-process rights of public employees. These particular rights are grounded in the constitutionally protected liberty interest in one's good name and reputation. Both employers and employees should be aware of what parameters case law provides with regard to the dimensions of this due-process right and…
Dynamic Performance of a Back-to-Back HVDC Station Based on Voltage Source Converters
NASA Astrophysics Data System (ADS)
Khatir, Mohamed; Zidi, Sid-Ahmed; Hadjeri, Samir; Fellah, Mohammed-Karim
2010-01-01
The recent developments in semiconductors and control equipment have made the voltage source converter based high voltage direct current (VSC-HVDC) feasible. This new DC transmission is known as "HVDC Light or "HVDC Plus by leading vendors. Due to the use of VSC technology and pulse width modulation (PWM) the VSC-HVDC has a number of potential advantages as compared with classic HVDC. In this paper, the scenario of back-to-back VSC-HVDC link connecting two adjacent asynchronous AC networks is studied. Control strategy is implemented and its dynamic performances during disturbances are investigated in MATLAB/Simulink program. The simulation results have shown good performance of the proposed system under balanced and unbalanced fault conditions.
Secure positioning technique based on the encrypted visible light map
NASA Astrophysics Data System (ADS)
Lee, Y. U.; Jung, G.
2017-01-01
For overcoming the performance degradation problems of the conventional visible light (VL) positioning system, which are due to the co-channel interference by adjacent light and the irregularity of the VL reception position in the three dimensional (3-D) VL channel, the secure positioning technique based on the two dimensional (2-D) encrypted VL map is proposed, implemented as the prototype for the specific embedded positioning system, and verified by performance tests in this paper. It is shown from the test results that the proposed technique achieves the performance enhancement over 21.7% value better than the conventional one in the real positioning environment, and the well known PN code is the optimal stream encryption key for the good VL positioning.
Feng, Songfu; Chen, Han; Liu, Yaqin; Huang, Zhen; Sun, Xuyuan; Zhou, Lian; Lu, Xiaohe; Gao, Qianying
2013-01-01
Hydrogels may be the ideal vitreous substitutes due to their wonderful physical features and biocompatibility. However, their drawbacks, short residence time, and biodegradation in vivo, have led to the fact that none of them have been approved for clinical use. In this study, we developed a novel approach of using a foldable capsular vitreous body (FCVB) injected with polyvinylalcohol (PVA) hydrogel as a vitreous substitute for long-term tamponade. The 3% PVA hydrogel that was cross-linked by gamma irradiation showed good rheological and physical properties and had no toxicity in vitro. After 180 days retention, the 3% PVA hydrogel inside FCVB remained transparent and showed good viscoelasticity without biodegradation and showed good biocompatibility and retina support. This new approach may develop into a valuable tool to improve the stability performance of PVA hydrogel as a vitreous substitute and to extend the application function of FCVB for long-term implantation in vitreous cavity. PMID:23670585
Feng, Songfu; Chen, Han; Liu, Yaqin; Huang, Zhen; Sun, Xuyuan; Zhou, Lian; Lu, Xiaohe; Gao, Qianying
2013-01-01
Hydrogels may be the ideal vitreous substitutes due to their wonderful physical features and biocompatibility. However, their drawbacks, short residence time, and biodegradation in vivo, have led to the fact that none of them have been approved for clinical use. In this study, we developed a novel approach of using a foldable capsular vitreous body (FCVB) injected with polyvinylalcohol (PVA) hydrogel as a vitreous substitute for long-term tamponade. The 3% PVA hydrogel that was cross-linked by gamma irradiation showed good rheological and physical properties and had no toxicity in vitro. After 180 days retention, the 3% PVA hydrogel inside FCVB remained transparent and showed good viscoelasticity without biodegradation and showed good biocompatibility and retina support. This new approach may develop into a valuable tool to improve the stability performance of PVA hydrogel as a vitreous substitute and to extend the application function of FCVB for long-term implantation in vitreous cavity.
Guarneri, Paolo; Rocca, Gianpiero; Gobbi, Massimiliano
2008-09-01
This paper deals with the simulation of the tire/suspension dynamics by using recurrent neural networks (RNNs). RNNs are derived from the multilayer feedforward neural networks, by adding feedback connections between output and input layers. The optimal network architecture derives from a parametric analysis based on the optimal tradeoff between network accuracy and size. The neural network can be trained with experimental data obtained in the laboratory from simulated road profiles (cleats). The results obtained from the neural network demonstrate good agreement with the experimental results over a wide range of operation conditions. The NN model can be effectively applied as a part of vehicle system model to accurately predict elastic bushings and tire dynamics behavior. Although the neural network model, as a black-box model, does not provide a good insight of the physical behavior of the tire/suspension system, it is a useful tool for assessing vehicle ride and noise, vibration, harshness (NVH) performance due to its good computational efficiency and accuracy.
Low cost microfluidic device based on cotton threads for electroanalytical application.
Agustini, Deonir; Bergamini, Márcio F; Marcolino-Junior, Luiz Humberto
2016-01-21
Microfluidic devices are an interesting alternative for performing analytical assays, due to the speed of analyses, reduced sample, reagent and solvent consumption and less waste generation. However, the high manufacturing costs still prevent the massive use of these devices worldwide. Here, we present the construction of a low cost microfluidic thread-based electroanalytical device (μTED), employing extremely cheap materials and a manufacturing process free of equipment. The microfluidic channels were built with cotton threads and the estimated cost per device was only $0.39. The flow of solutions (1.12 μL s(-1)) is generated spontaneously due to the capillary forces, eliminating the use of any pumping system. To demonstrate the analytical performance of the μTED, a simultaneous determination of acetaminophen (ACT) and diclofenac (DCF) was performed by multiple pulse amperometry (MPA). A linear dynamic range (LDR) of 10 to 320 μmol L(-1) for both species, a limit of detection (LOD) and a limit of quantitation (LOQ) of 1.4 and 4.7 μmol L(-1) and 2.5 and 8.3 μmol L(-1) for ACT and DCF, respectively, as well as an analytical frequency of 45 injections per hour were reached. Thus, the proposed device has shown potential to extend the use of microfluidic analytical devices, due to its simplicity, low cost and good analytical performance.
Relationship between time management in construction industry and project management performance
NASA Astrophysics Data System (ADS)
Nasir, Najuwa; Nawi, Mohd Nasrun Mohd; Radzuan, Kamaruddin
2016-08-01
Nowadays, construction industry particularly in Malaysia struggle in achieving status of eminent time management for construction project. Project managers have a great responsibility to keep the project success under time of project completion. However, studies shows that delays especially in Malaysian construction industry still unresolved due to weakness in managing the project. In addition, quality of time management on construction projects is generally poor. Due to the progressively extended delays issue, time performance becomes an important subject to be explored to investigate delay factors. The method of this study is review of literature towards issues in construction industry which affecting time performance of project in general by focusing towards process involved for project management. Based on study, it was found that knowledge, commitment, cooperation are the main criteria as an overall to manage the project into a smooth process during project execution until completion. It can be concluded that, the strength between project manager and team members in these main criteria while conducting the project towards good time performance is highly needed. However, there is lack of establishment towards factors of poor time performance which strongly related with project management. Hence, this study has been conducted to establish factors of poor time performance and its relations with project management.
Peng, Yuyang; Choi, Jaeho
2014-01-01
Improving the energy efficiency in wireless sensor networks (WSN) has attracted considerable attention nowadays. The multiple-input multiple-output (MIMO) technique has been proved as a good candidate for improving the energy efficiency, but it may not be feasible in WSN which is due to the size limitation of the sensor node. As a solution, the cooperative multiple-input multiple-output (CMIMO) technique overcomes this constraint and shows a dramatically good performance. In this paper, a new CMIMO scheme based on the spatial modulation (SM) technique named CMIMO-SM is proposed for energy-efficiency improvement. We first establish the system model of CMIMO-SM. Based on this model, the transmission approach is introduced graphically. In order to evaluate the performance of the proposed scheme, a detailed analysis in terms of energy consumption per bit of the proposed scheme compared with the conventional CMIMO is presented. Later, under the guide of this new scheme we extend our proposed CMIMO-SM to a multihop clustered WSN for further achieving energy efficiency by finding an optimal hop-length. Equidistant hop as the traditional scheme will be compared in this paper. Results from the simulations and numerical experiments indicate that by the use of the proposed scheme, significant savings in terms of total energy consumption can be achieved. Combining the proposed scheme with monitoring sensor node will provide a good performance in arbitrary deployed WSN such as forest fire detection system.
Lobacheva, Tatiana; Asikainen, Tommi; Giesecke, Johan
2007-01-01
Detainees have a substantial risk to develop tuberculosis (TB) due to a higher incidence of TB in remand prison compared to the civil community. They develop TB during incarceration not only due to poor living conditions in remand prison, but also due to some factors affecting their life before imprisonment. Prevention measures against TB spread from penitentiary institutions to society include study of factors, which contribute to TB development. Current study aims at identification of important risk factors of TB development in remand prison in St. Petersburg, Russia. A retrospective matched case-control study was performed from May 2002 to May 2003 in two remand prisons in St. Petersburg. One hundred and fourteen prisoners (57 cases, 57 controls) were interviewed by using standardised questionnaire. Logistic regression analysis was performed to identify risk factors. Six factors were significantly linked to the risk of developing TB: narcotic drug use (odds ratio (OR): 2.6, 95% confidence interval (CI): 1.0-6.9), low income (OR: 3.2, CI: 1.2-8.6), high ratio of prisoners per available bed (OR: 4.0, CI: 1.1-15.0), not having own bed clothes (OR: 13.0, CI: 2.7-61.6), and little time outdoors (OR: 3.3, CI: 1.3-8.5). However, good housing before imprisonment (OR: 4.2, CI: 1.1-15.7) was a separate risk factor for TB. Three of the risk factors (high number of prisoners per bed, not having own bed clothes, and little time outdoors) are certainly possible to approach by improvement of conditions in remand prisons. The remaining three factors (narcotic drug use, good housing before imprisonment, and low income) provide knowledge about study population, but cannot be intervened by prison's medical staff.
Antegrade Ureteral Stenting is a Good Alternative for the Retrograde Approach
van der Meer, Rutger W.; Weltings, Saskia; van Erkel, Arian R.; Roshani, Hossain; Elzevier, Henk W.; van Dijk, Lukas C.; van Overhagen, Hans
2017-01-01
Background/Aims Double J (JJ) stents for treating obstructive ureteral pathology are generally inserted through a retrograde route with cystoscopic guidance. Antegrade percutaneous insertion using fluoroscopy can be performed alternatively but is less known. Indications, success rate and complications of antegrade ureteral stenting were evaluated. Methods Data of consecutive patients in which antegrade ureteral stenting was performed were retrospectively analysed using the radiology information system and patient records. Patient characteristics, details of the antegrade JJ stent insertion procedure and registered complications were collected. Furthermore, it was investigated if prior to the antegrade procedure a retrograde attempt for JJ stent insertion was performed. Results Total 130 attempts for antegrade JJ stent insertion were performed in 100 patients. A percutaneous nephrostomy catheter had already been placed in the majority of kidneys (n = 109) for initial treatment of hydronephrosis. Most prevelant indication for a JJ stent was obstructive ureteral pathology due to malignancy (n = 63). A JJ stent was successfully inserted in 125 of 130 procedures. In 21 cases, previous retrograde ureteral stenting had failed but, subsequent antegrade ureteral stenting was successful. There were 8 procedure related complications; 6 infections, 1 false tract and 1 malposition. Conclusion Antegrade percutaneous insertion of a JJ stent is a good alternative for retrograde insertion. PMID:28785193
Modeling study of air pollution due to the manufacture of export goods in China's Pearl River Delta.
Streets, David G; Yu, Carolyne; Bergin, Michael H; Wang, Xuemei; Carmichael, Gregory R
2006-04-01
The Pearl River Delta is a major manufacturing region on the south coast of China that produces more than dollar 100 billion of goods annually for export to North America, Europe, and other parts of Asia. Considerable air pollution is caused by the manufacturing industries themselves and by the power plants, trucks, and ships that support them. We estimate that 10-40% of emissions of primary SO2, NO(x), RSP, and VOC in the region are caused by export-related activities. Using the STEM-2K1 atmospheric transport model, we estimate that these emissions contribute 5-30% of the ambient concentrations of SO2, NO(x), NO(z), and VOC in the region. One reason that the exported goods are cheap and therefore attractive to consumers in developed countries is that emission controls are lacking or of low performance. We estimate that state-of-the-art controls could be installed at an annualized cost of dollar 0.3-3 billion, representing 0.3-3% of the value of the goods produced. We conclude that mitigation measures could be adopted without seriously affecting the prices of exported goods and would achieve considerable human health and other benefits in the form of reduced air pollutant concentrations in densely populated urban areas.
New Vectorial Propulsion System and Trajectory Control Designs for Improved AUV Mission Autonomy
Gonzalez, Julian; Galarza, Cesar; Aguzzi, Jacopo; del Rio, Joaquin
2018-01-01
Autonomous Underwater Vehicles (AUV) are proving to be a promising platform design for multidisciplinary autonomous operability with a wide range of applications in marine ecology and geoscience. Here, two novel contributions towards increasing the autonomous navigation capability of a new AUV prototype (the Guanay II) as a mix between a propelled vehicle and a glider are presented. Firstly, a vectorial propulsion system has been designed to provide full vehicle maneuverability in both horizontal and vertical planes. Furthermore, two controllers have been designed, based on fuzzy controls, to provide the vehicle with autonomous navigation capabilities. Due to the decoupled system propriety, the controllers in the horizontal plane have been designed separately from the vertical plane. This class of non-linear controllers has been used to interpret linguistic laws into different zones of functionality. This method provided good performance, used as interpolation between different rules or linear controls. Both improvements have been validated through simulations and field tests, displaying good performance results. Finally, the conclusion of this work is that the Guanay II AUV has a solid controller to perform autonomous navigation and carry out vertical immersions. PMID:29673224
A knittable fiber-shaped supercapacitor based on natural cotton thread for wearable electronics
NASA Astrophysics Data System (ADS)
Zhou, Qianlong; Jia, Chunyang; Ye, Xingke; Tang, Zhonghua; Wan, Zhongquan
2016-09-01
At present, the topic of building high-performance, miniaturized and mechanically flexible energy storage modules which can be directly integrated into textile based wearable electronics is a hotspot in the wearable technology field. In this paper, we reported a highly flexible fiber-shaped electrode fabricated through a one-step convenient hydrothermal process. The prepared graphene hydrogels/multi-walled carbon nanotubes-cotton thread derived from natural cotton thread is electrochemically active and mechanically strong. Fiber-shaped supercapacitor based on the prepared fiber electrodes and polyvinyl alcohol-H3PO4 gel electrolyte exhibits good capacitive performance (97.73 μF cm-1 at scan rate of 2 mV s-1), long cycle life (95.51% capacitance retention after 8000 charge-discharge cycles) and considerable stability (90.75% capacitance retention after 500 continuous bending cycles). Due to its good mechanical and electrochemical properties, the graphene hydrogels/multi-walled carbon nanotubes-cotton thread based all-solid fiber-shaped supercapacitor can be directly knitted into fabrics and maintain its original capacitive performance. Such a low-cost textile thread based versatile energy storage device may hold great potential for future wearable electronics applications.
NASA Astrophysics Data System (ADS)
Insulander Björk, Klara; Kekkonen, Laura
2015-12-01
Thorium-plutonium Mixed OXide (Th-MOX) fuel is considered for use in light water reactors fuel due to some inherent benefits over conventional fuel types in terms of neutronic properties. The good material properties of ThO2 also suggest benefits in terms of thermal-mechanical fuel performance, but the use of Th-MOX fuel for commercial power production demands that its thermal-mechanical behavior can be accurately predicted using a well validated fuel performance code. Given the scant operational experience with Th-MOX fuel, no such code is available today. This article describes the first phase of the development of such a code, based on the well-established code FRAPCON 3.4, and in particular the correlations reviewed and chosen for the fuel material properties. The results of fuel temperature calculations with the code in its current state of development are shown and compared with data from a Th-MOX test irradiation campaign which is underway in the Halden research reactor. The results are good for fresh fuel, whereas experimental complications make it difficult to judge the adequacy of the code for simulations of irradiated fuel.
A 6DOF passive vibration isolator using X-shape supporting structures
NASA Astrophysics Data System (ADS)
Wu, Zhijing; Jing, Xingjian; Sun, Bo; Li, Fengming
2016-10-01
A novel 6 degree of freedom (6-DOF) passive vibration isolator is studied theoretically and validated with experiments. Based on the Stewart platform configuration, the 6-DOF isolator is constructed by 6 X-shape structures as legs, which can realize very good and tunable vibration isolation performance in all 6 directions with a passive manner. The mechanic model is established for static analysis of the working range, static stiffness and loading capacity. Thereafter, the equation of motion of the isolator is derived with the Hamilton principle. The equivalent stiffness and the displacement transmissibility in the six decoupled DOFs direction are then discussed with experimental results for validation. The results reveal that (a) by designing the structure parameters, the system can possess flexible stiffness such as negative, quasi-zero and positive stiffness, (b) due to the combination of the Stewart platform and the X-shape structure, the system can have very good vibration isolation performance in all the 6 directions and in a passive manner, and (c) compared with the simplified linear-stiffness legs, the nonlinearity of the X-shape structures enhance the passive isolator to have much better vibration isolation performance.
Powdery Emulsion Explosive: A New Excellent Industrial Explosive
NASA Astrophysics Data System (ADS)
Ni, Ouqi; Zhang, Kaiming; Yu, Zhengquan; Tang, Shujuan
2012-07-01
Powdery emulsion explosive (PEE), a new powdery industrial explosive with perfect properties, has been made using an emulsification-spray drying technique. PEE is composed of 91-92.5 wt% ammonium nitrate (AN), 4.5-6 wt% organic fuels, and 1.5-1.8 wt% water. Due to its microstructure as a water-in-oil (W/O) emulsion and low water content, it has excellent detonation performance, outstanding water resistance, reliable safety, and good application compared with other industrial explosives, such as ammonite, emulsion explosives, and ANFO.
Design and characterization of very high frequency pulse tube prototypes
NASA Astrophysics Data System (ADS)
Lopes, Diogo; Duval, Jean-Marc; Charles, Ivan; Butterworth, James; Trollier, Thierry; Tanchon, Julien; Ravex, Alain; Daniel, Christophe
2012-06-01
Weight and size are important features of a cryocooler when it comes to space applications. Given their reliability and low level of exported vibrations (due to the absence of moving cold parts), pulse tubes are good candidates for spatial purposes and their miniaturization has been the focus of many studies. We report on the design and performance of a small-scale very high frequency pulse tube prototype, modeled after two previous prototypes which were optimized with a numerical code.
Work Loop and Ashby Charts of Active Materials
2013-10-17
constructed to show performance metrics (e.g., actuation stress, actuation strain, self - healing ) of iron-loaded compositions compared to other active...24,000 cycles at 80 Hz without change in strain characteristics. Self - healing of Magpol prepared using ferrite nanoparticles of different Curie...silicone) was selected as the polymer matrix due to its good flexibility and reasonable environmental stability. Self healing Magpol was synthesized by
Fixation of operating point and measurement of turn on characteristics of IGBT F4-75R06W1E3
NASA Astrophysics Data System (ADS)
Haseena, A.; Subhash Joshi T., G.; George, Saly
2018-05-01
For the proficient operation of the Power electronic circuit, signal level performance of power electronic devices are very important. For getting good signal level characteristics, fixing operating point is very critical. Device deviates from the typical characteristics given in the datasheet due to the presence of stray components in the circuit lay out. Fixation of operating point of typical silicon IGBT and its turn on characteristics is discussed in this paper.
Tchernev, Georgi; Lozev, Ilia; Lotti, Torello; Wollina, Uwe; Gianfaldoni, Serena; Guarneri, Claudio; Lotti, Jacopo; França, Katlein; Batashki, Atanas; Chokoeva, Anastasiya
2017-07-25
Dermatosurgery and dermatooncology are an integral part of dermatology as a speciality, and this postulate is strictly respected in a high percentage of European dermatological units. Due to the fact that a number of other specialties interweave with the subject of therapy - the surgical treatment of the patient with skin tumors, the positioning of dermatosurgery as part of dermatology is generally controversial (according to some), and at the same time is often the subject of a number of debates and conflicts. These include maxillofacial surgeons, plastic surgeons, regenerative and reconstructive surgeons, surgical and medical oncologist, etc. The advantages of these specialities are mainly based on good medical practice and good surgical techniques that are applied. In contrast, their disadvantages are based on the lack of good awareness of the initial surgical approach as well as the need for time-adjusted and accurately performed additional surgical interventions which should befurthermore careful scheduled with the relevant oncology units. Losing this thread, in practice, it turns out that we are losing the patients themselves or, looking laconically, we are working with reduced efficiency and effectiveness. Although for the last 15 years the positions of these sub-sectors in Bulgaria had been underdeveloped, a certain ascent has been observed nowadays or from a couple of years ago. This advance is undoubtedly due to the influence of the German Dermatological School, presented by Prof. Dr. Uwe Wollina, Head of Department of Dermatology, Venereology and Allergology in Dresden, Germany, as well as due to other respected representative of the Italian Dermatological School - in the face of Prof. Dr. Torello Lotti, Head of the Dermatology Unit at G Marconi University of Rome, Italy.
Multiple scales in metapopulations of public goods producers
NASA Astrophysics Data System (ADS)
Bauer, Marianne; Frey, Erwin
2018-04-01
Multiple scales in metapopulations can give rise to paradoxical behavior: in a conceptual model for a public goods game, the species associated with a fitness cost due to the public good production can be stabilized in the well-mixed limit due to the mere existence of these scales. The scales in this model involve a length scale corresponding to separate patches, coupled by mobility, and separate time scales for reproduction and interaction with a local environment. Contrary to the well-mixed high mobility limit, we find that for low mobilities, the interaction rate progressively stabilizes this species due to stochastic effects, and that the formation of spatial patterns is not crucial for this stabilization.
Teacher performance and work environment in the instructional process in vocational school
NASA Astrophysics Data System (ADS)
Kuncoro, Tri; Dardiri, Ahmad
2017-09-01
Teachers should have pedagogical, personality, social, and professional competency. stated that performance appraisal has several benefits, namely for the implementation of reward and punishment system, provision of feedback for teachers to develop their competencies, identification of training needs, and diagnosis of problems. According to performance is one's work result or success rate as a whole over a certain period of time in performing tasks compared to various possibilities, such as work standards, targets or criteria which have been predetermined and agreed. One's performance is based on daily tasks and responsibilities assigned to him/her. The racial differences in personality are largely due to different environmental influences, where people of different races have progressed for generations. Vocational high school teachers have a low pedagogic and professional performance. The factors that influence performance, according to the partner-lawyer model proposed, are expectations about rewards, encouragements, abilities, needs and traits, perceptions of tasks, internal and external rewards, perceptions of reward levels and job satisfaction. This study used a survey method to collect data or information about a large population using relatively small samples. The population of this research was vocational high school teachers. Data analysis techniques used the Regression Analysis with the assistance of SPSS. The results of teacher performance are as follows: 1) the pedagogic performance was relatively good; 2) professional performance was relatively good, and the overall performance of vocational high school teachers was still less effective and efficient; 3) the teachers' work environment was 42.5234%; and 4) there was no correlation between work environment and teacher performance, meaning that the work environment (conditions of physical work environment, psychological work environment, and non-physical work environment) does not positively support the pedagogical and professional performance of teachers.
Garcia, Santiago; Drexel, Todd; Bekwelem, Wobo; Raveendran, Ganesh; Caldwell, Emily; Hodgson, Lucinda; Wang, Qi; Adabag, Selcuk; Mahoney, Brian; Frascone, Ralph; Helmer, Gregory; Lick, Charles; Conterato, Marc; Baran, Kenneth; Bart, Bradley; Bachour, Fouad; Roh, Steven; Panetta, Carmelo; Stark, Randall; Haugland, Mark; Mooney, Michael; Wesley, Keith; Yannopoulos, Demetris
2016-01-07
In 2013 the Minnesota Resuscitation Consortium developed an organized approach for the management of patients resuscitated from shockable rhythms to gain early access to the cardiac catheterization laboratory (CCL) in the metro area of Minneapolis-St. Paul. Eleven hospitals with 24/7 percutaneous coronary intervention capabilities agreed to provide early (within 6 hours of arrival at the Emergency Department) access to the CCL with the intention to perform coronary revascularization for outpatients who were successfully resuscitated from ventricular fibrillation/ventricular tachycardia arrest. Other inclusion criteria were age >18 and <76 and presumed cardiac etiology. Patients with other rhythms, known do not resuscitate/do not intubate, noncardiac etiology, significant bleeding, and terminal disease were excluded. The primary outcome was survival to hospital discharge with favorable neurological outcome. Patients (315 out of 331) who were resuscitated from VT/VF and transferred alive to the Emergency Department had complete medical records. Of those, 231 (73.3%) were taken to the CCL per the Minnesota Resuscitation Consortium protocol while 84 (26.6%) were not taken to the CCL (protocol deviations). Overall, 197 (63%) patients survived to hospital discharge with good neurological outcome (cerebral performance category of 1 or 2). Of the patients who followed the Minnesota Resuscitation Consortium protocol, 121 (52%) underwent percutaneous coronary intervention, and 15 (7%) underwent coronary artery bypass graft. In this group, 151 (65%) survived with good neurological outcome, whereas in the group that did not follow the Minnesota Resuscitation Consortium protocol, 46 (55%) survived with good neurological outcome (adjusted odds ratio: 1.99; [1.07-3.72], P=0.03). Early access to the CCL after cardiac arrest due to a shockable rhythm in a selected group of patients is feasible in a large metropolitan area in the United States and is associated with a 65% survival rate to hospital discharge with a good neurological outcome. © 2016 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.
Cai, Rui; Tao, Gang; He, Huawei; Song, Kai; Zuo, Hua; Jiang, Wenchao; Wang, Yejing
2017-04-30
Silk sericin has great potential as a biomaterial for biomedical applications due to its good hydrophilicity, reactivity, and biodegradability. To develop multifunctional sericin materials for potential antibacterial application, a one-step synthesis method for preparing silver nanoparticles (AgNPs) modified on polydopamine-coated sericin/polyvinyl alcohol (PVA) composite films was developed. Polydopamine (PDA) acted as both metal ion chelating and reducing agent to synthesize AgNPs in situ on the sericin/PVA composite film. Scanning electron microscopy and energy dispersive spectroscopy analysis revealed that polydopamine could effectively facilitate the high-density growth of AgNPs as a 3-D matrix. X-ray diffractometry studies suggested the synthesized AgNPs formed good face-centered cubic crystalline structures. Contact angle measurement and mechanical test indicated AgNPs modified PDA-sericin/PVA composite film had good hydrophilicity and mechanical property. The bacterial growth curve and inhibition zone assays showed the AgNPs modified PDA-sericin/PVA composite film had long-term antibacterial activities. This work develops a new method for the preparation of AgNPs modified PDA-sericin/PVA film with good hydrophilicity, mechanical performance and antibacterial activities for the potential antimicrobial application in biomedicine.
Advanced analytical modeling of double-gate Tunnel-FETs - A performance evaluation
NASA Astrophysics Data System (ADS)
Graef, Michael; Hosenfeld, Fabian; Horst, Fabian; Farokhnejad, Atieh; Hain, Franziska; Iñíguez, Benjamín; Kloes, Alexander
2018-03-01
The Tunnel-FET is one of the most promising devices to be the successor of the standard MOSFET due to its alternative current transport mechanism, which allows a smaller subthreshold slope than the physically limited 60 mV/dec of the MOSFET. Recently fabricated devices show smaller slopes already but mostly not over multiple decades of the current transfer characteristics. In this paper the performance limiting effects, occurring during the fabrication process of the device, such as doping profiles and midgap traps are analyzed by physics-based analytical models and their performance limiting abilities are determined. Additionally, performance enhancing possibilities, such as hetero-structures and ambipolarity improvements are introduced and discussed. An extensive double-gate n-Tunnel-FET model is presented, which meets the versatile device requirements and shows a good fit with TCAD simulations and measurement data.
NASA Astrophysics Data System (ADS)
Yadav, Priya; Nautiyal, Shashank; Verma, U. P.
2018-04-01
Ternary skutterudites materials exhibit good electronic properties due to the unpaired d- and f- electrons of the transition and rare-earth metals, respectively. In this communication, we have performed the structural optimization of Pr-based filled skutterudite (PrCo4P12) for the first time and obtained the electronic band structure, density of states and magnetic moments by using the full-potential linearized augmented plane wave (FP-LAPW) method based on density functional theory (DFT). Our obtained magnetic moment of PrCo4P12 is ˜ 1.8 µB in which main contribution is due to Pr atom. Behavior of this material is metallic and it is most stable in body centered cubic (BCC) structure.
Temperature coefficients and radiation induced DLTS spectra of MOCVD grown n(+)p InP solar cells
NASA Technical Reports Server (NTRS)
Walters, Robert J.; Statler, Richard L.; Summers, Geoffrey P.
1991-01-01
The effects of temperature and radiation on n(+)p InP solar cells and mesa diodes grown by metallorganic chemical vapor deposition (MOCVD) were studied. It was shown that MOCVD is capable of consistently producing good quality InP solar cells with Eff greater than 19 percent which display excellent radiation resistance due to minority carrier injection and thermal annealing. It was also shown that universal predictions of InP device performance based on measurements of a small group of test samples can be expected to be quite accurate, and that the degradation of an InP device due to any incident particle spectrum should be predictable from a measurement following a single low energy proton irradiation.
CFD Assessment of Aerodynamic Degradation of a Subsonic Transport Due to Airframe Damage
NASA Technical Reports Server (NTRS)
Frink, Neal T.; Pirzadeh, Shahyar Z.; Atkins, Harold L.; Viken, Sally A.; Morrison, Joseph H.
2010-01-01
A computational study is presented to assess the utility of two NASA unstructured Navier-Stokes flow solvers for capturing the degradation in static stability and aerodynamic performance of a NASA General Transport Model (GTM) due to airframe damage. The approach is to correlate computational results with a substantial subset of experimental data for the GTM undergoing progressive losses to the wing, vertical tail, and horizontal tail components. The ultimate goal is to advance the probability of inserting computational data into the creation of advanced flight simulation models of damaged subsonic aircraft in order to improve pilot training. Results presented in this paper demonstrate good correlations with slope-derived quantities, such as pitch static margin and static directional stability, and incremental rolling moment due to wing damage. This study further demonstrates that high fidelity Navier-Stokes flow solvers could augment flight simulation models with additional aerodynamic data for various airframe damage scenarios.
Zhang, Zinxin; Mwadini, Mwadini Ahmada; Chen, Zilin
2016-10-01
Steel stirrers jacketed with polytetrafluoroethylene can be regarded as an ideal substrate for stirrer bar sorptive extraction. However, it is still a great challenge to immobilize graphene onto a polytetrafluoroethylene stirrer due to the high chemical resistance of the surface of a polytetrafluoroethylene stirrer. We describe here a method to modify the surface of polytetrafluoroethylene stirrers with graphene. In this work, graphene was used as the sorbent due to its excellent adsorption capability for aromatic compounds, such as polycyclic aromatic compounds. Graphene was successfully immobilized onto polytetrafluoroethylene-stirrer by a bio-inspired polydopamine functionalization method. The graphene-modified polytetrafluoroethylene-stirrer shows good stability and tolerance to stirring, ultrasonication, strong acidic and basic solutions, and to organic solvents. The multilayer coating was characterized by scanning electronic microscopy and Fourier transform infrared spectroscopy. After the optimization of some experimental conditions, the graphene-modified polytetrafluoroethylene stirrer was used for the stirrer bar sorptive extraction of polycyclic aromatic hydrocarbons, in which the binding between the polycyclic aromatic hydrocarbons and the graphene layer was mainly based on π-π stacking and hydrophobic interactions. The graphene-modified polytetrafluoroethylene-stirrer-based stirrer bar sorptive extraction and high-performance liquid chromatography method was developed for the determination of polycyclic aromatic hydrocarbons with great extraction efficiency, with enrichment factors from 18 to 62. The method has low limits of detection of 1-5 pg/mL, wide linear range (5-100 and 10-200 pg/mL), good linearity (R ≥ 0.9957) and good reproducibility (RSD ≤ 6.45%). The proposed method has been applied to determine polycyclic aromatic hydrocarbons in real dust samples. Good recoveries were obtained, ranging from 88.53 to 109.43%. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Optimization of a miniature Maglev ventricular assist device for pediatric circulatory support.
Zhang, Juntao; Koert, Andrew; Gellman, Barry; Gempp, Thomas M; Dasse, Kurt A; Gilbert, Richard J; Griffith, Bartley P; Wu, Zhongjun J
2007-01-01
A miniature Maglev blood pump based on magnetically levitated bearingless technology is being developed and optimized for pediatric patients. We performed impeller optimization by characterizing the hemodynamic and hemocompatibility performances using a combined computational and experimental approach. Both three-dimensional flow features and hemolytic characteristics were analyzed using computational fluid dynamics (CFD) modeling. Hydraulic pump performances and hemolysis levels of three different impeller designs were quantified and compared numerically. Two pump prototypes were constructed from the two impeller designs and experimentally tested. Comparison of CFD predictions with experimental results showed good agreement. The optimized impeller remarkably increased overall pump hydraulic output by more than 50% over the initial design. The CFD simulation demonstrated a clean and streamlined flow field in the main flow path. The numerical results by hemolysis model indicated no significant high shear stress regions. Through the use of CFD analysis and bench-top testing, the small pediatric pump was optimized to achieve a low level of blood damage and improved hydraulic performance and efficiency. The Maglev pediatric blood pump is innovative due to its small size, very low priming volume, excellent hemodynamic and hematologic performance, and elimination of seal-related and bearing-related failures due to adoption of magnetically levitated bearingless motor technology, making it ideal for pediatric applications.
Leufkens, T R M; Ramaekers, J G; de Weerd, A W; Riedel, W J; Vermeeren, A
2014-07-01
Residual effects of hypnotics on driving performance have been mainly determined in studies using a standardized driving test with healthy good sleepers. Responses to effects may differ, however, between insomniacs and healthy volunteers due to the underlying sleep disorder. In addition, a majority of insomniacs uses hypnotics chronically resulting in the development of tolerance to impairing effects. Impaired driving performance in healthy volunteers may then be an overestimation of the actual effects in insomniacs. The present study aims to compare the residual effects of zopiclone 7.5 mg on on-the-road driving performance of 16 middle-aged insomniacs chronically using hypnotics (chronic users), 16 middle-aged insomniacs not or infrequently using hypnotics (infrequent users), and 16 healthy, age matched, good sleepers (controls). The study was conducted according to a 3 × 2 double-blind, placebo controlled crossover design, with three groups and two treatment conditions. Treatments were single oral doses of zopiclone 7.5 mg and placebo administered at bedtime (2330 hours). Between 10 and 11 h after administration subjects performed a standardized highway driving test. Zopiclone 7.5 mg significantly impaired on-the-road driving performance in both insomnia groups and healthy controls. The magnitude of impairment was significantly less in the chronic users group as compared with the controls. The smaller magnitude of effects suggests that investigating residual effects of hypnotics in healthy volunteers may yield a minor overestimation of the actual effects in insomnia patients.
CO2 Separation Using Thermally Optimized Membranes: A Comprehensive Project Report (2000 - 2007)
DOE Office of Scientific and Technical Information (OSTI.GOV)
J.R. Klaehn; C.J. Orme; E.S. Peterson
2008-03-01
This is a complete (Fiscal Years 2000–2006) collection of the Idaho National Laboratory’s (INL) research and development contributions to the project, “CO2 Separation Using Thermally Optimized Membranes.” The INL scientific contribution to the project has varied due to the fluctuations in funding from year to year. The focus of the project was polybenzimidazole (PBI) membranes and developing PBI compounds (both substitution and blends) that provide good film formation and gas separation membranes. The underlying problem with PBI is its poor solubility in common solvents. Typically, PBI is dissolved in “aggressive” solvents, like N,N-dimethylacetamide (DMAc) and N methylpyrrolidone (NMP). The INLmore » FY-03 research was directed toward making soluble N-substituted PBI polymers, where INL was very successful. Many different types of modified PBI polymers were synthesized; however, film formation proved to be a big problem with both unsubstituted and N-substituted PBIs. Therefore, INL researchers directed their attention to using plasticizers or additives to make the membranes more stable and workable. During the course of these studies, other high-performance polymers (like polyamides and polyimides) were found to be better materials, which could be used either by themselves or blends with PBI. These alternative high-performance polymers provided the best pathway forward for soluble high-temperature polymers with good stable film formation properties. At present, the VTEC polyimides (product of RBI, Inc.) are the best film formers that exhibit high-temperature resistance. INL’s gas testing results show VTEC polyimides have very good gas selectivities for both H2/CO2 and CO2/CH4. Overall, these high-performance polymers pointed towards new research areas where INL has gained a greater understanding of polymer film formation and gas separation. These studies are making possible a direct approach to stable polymer-based high-temperature gas separation membranes. This report is separated into several sections due to the complexity of the research and the variation with the development of better high-temperature, gas separation membranes. Several fiscal years are combined because the research and development efforts within those areas crossed fiscal year boundaries.« less
CO2 Separation Using Thermally Optimized Membranes: A Comprehensive Project Report (2000 - 2007)
DOE Office of Scientific and Technical Information (OSTI.GOV)
N /A
2008-03-04
This is a complete (Fiscal Years 2000–2006) collection of the Idaho National Laboratory’s (INL) research and development contributions to the project, “CO2 Separation Using Thermally Optimized Membranes.” The INL scientific contribution to the project has varied due to the fluctuations in funding from year to year. The focus of the project was polybenzimidazole (PBI) membranes and developing PBI compounds (both substitution and blends) that provide good film formation and gas separation membranes. The underlying problem with PBI is its poor solubility in common solvents. Typically, PBI is dissolved in “aggressive” solvents, like N,N-dimethylacetamide (DMAc) and N methylpyrrolidone (NMP). The INLmore » FY-03 research was directed toward making soluble N-substituted PBI polymers, where INL was very successful. Many different types of modified PBI polymers were synthesized; however, film formation proved to be a big problem with both unsubstituted and N-substituted PBIs. Therefore, INL researchers directed their attention to using plasticizers or additives to make the membranes more stable and workable. During the course of these studies, other high-performance polymers (like polyamides and polyimides) were found to be better materials, which could be used either by themselves or blends with PBI. These alternative high-performance polymers provided the best pathway forward for soluble high-temperature polymers with good stable film formation properties. At present, the VTEC polyimides (product of RBI, Inc.) are the best film formers that exhibit high-temperature resistance. INL’s gas testing results show VTEC polyimides have very good gas selectivities for both H2/CO2 and CO2/CH4. Overall, these high-performance polymers pointed towards new research areas where INL has gained a greater understanding of polymer film formation and gas separation. These studies are making possible a direct approach to stable polymer-based high-temperature gas separation membranes. This report is separated into several sections due to the complexity of the research and the variation with the development of better high-temperature, gas separation membranes. Several fiscal years are combined because the research and development efforts within those areas crossed fiscal year boundaries.« less
NASA Astrophysics Data System (ADS)
Ghani, N. H. A.; Mohamed, N. S.; Zull, N.; Shoid, S.; Rivaie, M.; Mamat, M.
2017-09-01
Conjugate gradient (CG) method is one of iterative techniques prominently used in solving unconstrained optimization problems due to its simplicity, low memory storage, and good convergence analysis. This paper presents a new hybrid conjugate gradient method, named NRM1 method. The method is analyzed under the exact and inexact line searches in given conditions. Theoretically, proofs show that the NRM1 method satisfies the sufficient descent condition with both line searches. The computational result indicates that NRM1 method is capable in solving the standard unconstrained optimization problems used. On the other hand, the NRM1 method performs better under inexact line search compared with exact line search.
[Manual material handling risk assessment and ergonomic improvement in foodstuff retailing company].
Maso, S; Maccà, I; Simonetti, A; Scopa, P; Paruzzolo, P; Bonacci, A; Murgolo, I; Bartolucci, G B
2011-01-01
The aim of this study is to assess and reduce the risk due to manual material handling in a company involved in the foodstuff retailing. The risk assessment was performed by NIOSH Variable Lifing Index in 13 different occupational conditions. As result the risk was present in any case, with VLI values ranging from 2.12 to 2.81. A good risk reduction has been accomplished correcting properly the most important multiplier involved in the computation of the revised NIOSH Lifting equation (lifting frequency and weight of heavier products). Even if the performed risk reduction has been significant, the residual risk is still higher than the level of acceptability.
Cao, Xuan; Lau, Christian; Liu, Yihang; Wu, Fanqi; Gui, Hui; Liu, Qingzhou; Ma, Yuqiang; Wan, Haochuan; Amer, Moh R; Zhou, Chongwu
2016-11-22
Semiconducting single-wall carbon nanotubes are ideal semiconductors for printed electronics due to their advantageous electrical and mechanical properties, intrinsic printability in solution, and desirable stability in air. However, fully printed, large-area, high-performance, and flexible carbon nanotube active-matrix backplanes are still difficult to realize for future displays and sensing applications. Here, we report fully screen-printed active-matrix electrochromic displays employing carbon nanotube thin-film transistors. Our fully printed backplane shows high electrical performance with mobility of 3.92 ± 1.08 cm 2 V -1 s -1 , on-off current ratio I on /I off ∼ 10 4 , and good uniformity. The printed backplane was then monolithically integrated with an array of printed electrochromic pixels, resulting in an entirely screen-printed active-matrix electrochromic display (AMECD) with good switching characteristics, facile manufacturing, and long-term stability. Overall, our fully screen-printed AMECD is promising for the mass production of large-area and low-cost flexible displays for applications such as disposable tags, medical electronics, and smart home appliances.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Fu, Shaofang; Zhu, Chengzhou; Su, Dong
As one of the alternatives to replace precious metal catalysts, transition-metal–nitrogen–carbon (M–N–C) electrocatalysts have attracted great research interest due to their low cost and good catalytic activities. Despite nanostructured M–N–C catalysts can achieve good electrochemical perfor-mances, they are vulnerable to aggregation and insufficient catalytic sites upon continuous catalytic reaction. In this work, metal–organic frameworks derived porous single-atom electrocatalysts (SAEs) were successfully prepared by simple pyrolysis procedure without any further posttreatment. Combining the X-ray absorption near-edge spectroscopy and electrochemical measure-ments, the SAEs have been identified with superior oxygen reduction reaction (ORR) activity and stability compared with Pt/C catalysts in alkaline condition.more » More impressively, the SAEs also show excellent ORR electrocatalytic perfor-mance in both acid and neutral media. This study of nonprecious catalysts provides new insights on nanoengineering catalytically active sites and porous structures for nonprecious metal ORR catalysis in a wide range of pH.« less
Lucas Martínez, Néstor; Martínez Ortega, José-Fernán; Hernández Díaz, Vicente; Del Toro Matamoros, Raúl M
2016-05-12
The deployment of the nodes in a Wireless Sensor and Actuator Network (WSAN) is typically restricted by the sensing and acting coverage. This implies that the locations of the nodes may be, and usually are, not optimal from the point of view of the radio communication. Additionally, when the transmission power is tuned for those locations, there are other unpredictable factors that can cause connectivity failures, like interferences, signal fading due to passing objects and, of course, radio irregularities. A control-based self-adaptive system is a typical solution to improve the energy consumption while keeping good connectivity. In this paper, we explore how the communication range for each node evolves along the iterations of an energy saving self-adaptive transmission power controller when using different parameter sets in an outdoor scenario, providing a WSAN that automatically adapts to surrounding changes keeping good connectivity. The results obtained in this paper show how the parameters with the best performance keep a k-connected network, where k is in the range of the desired node degree plus or minus a specified tolerance value.
Li, Xueqin; Hao, Changlong; Tang, Bochong; Wang, Yue; Liu, Mei; Wang, Yuanwei; Zhu, Yihua; Lu, Chenguang; Tang, Zhiyong
2017-02-09
Due to their high specific surface area and good electric conductivity, nitrogen-doped porous carbons (NPCs) and carbon nanotubes (CNTs) have attracted much attention for electrochemical energy storage applications. In the present work, we firstly prepared MWCNT/ZIF-8 composites by decoration of zeolitic imidazolate frameworks (ZIF-8) onto the surface of multi-walled CNTs (MWCNTs), then obtained MWCNT/NPCs by the direct carbonization of MWCNT/ZIF-8. By controlling the reaction conditions, MWCNT/ZIF-8 with three different particle sizes were synthesized. The effect of NPCs size on capacitance performance has been evaluated in detail. The MWCNT/NPC with large-sized NPC (MWCNT/NPC-L) displayed the highest specific capacitance of 293.4 F g -1 at the scan rate of 5 mV s -1 and only lost 4.2% of capacitance after 10 000 cyclic voltammetry cycles, which was attributed to the hierarchically structured pores, N-doping and high electrical conductivity. The studies of symmetric two-electrode supercapacitor cells also confirmed MWCNT/NPC-L as efficient electrode materials that have good electrochemical performance, especially for high-rate applications.
Lucas Martínez, Néstor; Martínez Ortega, José-Fernán; Hernández Díaz, Vicente; del Toro Matamoros, Raúl M.
2016-01-01
The deployment of the nodes in a Wireless Sensor and Actuator Network (WSAN) is typically restricted by the sensing and acting coverage. This implies that the locations of the nodes may be, and usually are, not optimal from the point of view of the radio communication. Additionally, when the transmission power is tuned for those locations, there are other unpredictable factors that can cause connectivity failures, like interferences, signal fading due to passing objects and, of course, radio irregularities. A control-based self-adaptive system is a typical solution to improve the energy consumption while keeping good connectivity. In this paper, we explore how the communication range for each node evolves along the iterations of an energy saving self-adaptive transmission power controller when using different parameter sets in an outdoor scenario, providing a WSAN that automatically adapts to surrounding changes keeping good connectivity. The results obtained in this paper show how the parameters with the best performance keep a k-connected network, where k is in the range of the desired node degree plus or minus a specified tolerance value. PMID:27187397
DOE Office of Scientific and Technical Information (OSTI.GOV)
Fu, Shaofang; Zhu, Chengzhou; Su, Dong
2018-02-01
As one of the alternatives to replace precious metal catalysts, transition-metal–nitrogen–carbon (M–N–C) electrocatalysts have attracted great research interest due to their low cost and good catalytic activities. Despite nanostructured M–N–C catalysts can achieve good electrochemical perfor-mances, they are vulnerable to aggregation and insufficient catalytic sites upon continuous catalytic reaction. In this work, metal–organic frameworks derived porous single-atom electrocatalysts (SAEs) were successfully prepared by simple pyrolysis procedure without any further posttreatment. Combining the X-ray absorption near-edge spectroscopy and electrochemical measure-ments, the SAEs have been identified with superior oxygen reduction reaction (ORR) activity and stability compared with Pt/C catalysts in alkaline condition.more » More impressively, the SAEs also show excellent ORR electrocatalytic perfor-mance in both acid and neutral media. This study of nonprecious catalysts provides new insights on nanoengineering catalytically active sites and porous structures for nonprecious metal ORR catalysis in a wide range of pH.« less
Storage element performance optimization for CMS analysis jobs
NASA Astrophysics Data System (ADS)
Behrmann, G.; Dahlblom, J.; Guldmyr, J.; Happonen, K.; Lindén, T.
2012-12-01
Tier-2 computing sites in the Worldwide Large Hadron Collider Computing Grid (WLCG) host CPU-resources (Compute Element, CE) and storage resources (Storage Element, SE). The vast amount of data that needs to processed from the Large Hadron Collider (LHC) experiments requires good and efficient use of the available resources. Having a good CPU efficiency for the end users analysis jobs requires that the performance of the storage system is able to scale with I/O requests from hundreds or even thousands of simultaneous jobs. In this presentation we report on the work on improving the SE performance at the Helsinki Institute of Physics (HIP) Tier-2 used for the Compact Muon Experiment (CMS) at the LHC. Statistics from CMS grid jobs are collected and stored in the CMS Dashboard for further analysis, which allows for easy performance monitoring by the sites and by the CMS collaboration. As part of the monitoring framework CMS uses the JobRobot which sends every four hours 100 analysis jobs to each site. CMS also uses the HammerCloud tool for site monitoring and stress testing and it has replaced the JobRobot. The performance of the analysis workflow submitted with JobRobot or HammerCloud can be used to track the performance due to site configuration changes, since the analysis workflow is kept the same for all sites and for months in time. The CPU efficiency of the JobRobot jobs at HIP was increased approximately by 50 % to more than 90 %, by tuning the SE and by improvements in the CMSSW and dCache software. The performance of the CMS analysis jobs improved significantly too. Similar work has been done on other CMS Tier-sites, since on average the CPU efficiency for CMSSW jobs has increased during 2011. Better monitoring of the SE allows faster detection of problems, so that the performance level can be kept high. The next storage upgrade at HIP consists of SAS disk enclosures which can be stress tested on demand with HammerCloud workflows, to make sure that the I/O-performance is good.
A Numerical Analysis of Heat Transfer and Effectiveness on Film Cooled Turbine Blade Tip Models
NASA Technical Reports Server (NTRS)
Ameri, A. A.; Rigby, D. L.
1999-01-01
A computational study has been performed to predict the distribution of convective heat transfer coefficient on a simulated blade tip with cooling holes. The purpose of the examination was to assess the ability of a three-dimensional Reynolds-averaged Navier-Stokes solver to predict the rate of tip heat transfer and the distribution of cooling effectiveness. To this end, the simulation of tip clearance flow with blowing of Kim and Metzger was used. The agreement of the computed effectiveness with the data was quite good. The agreement with the heat transfer coefficient was not as good but improved away from the cooling holes. Numerical flow visualization showed that the uniformity of wetting of the surface by the film cooling jet is helped by the reverse flow due to edge separation of the main flow.
Predictive Surface Roughness Model for End Milling of Machinable Glass Ceramic
NASA Astrophysics Data System (ADS)
Mohan Reddy, M.; Gorin, Alexander; Abou-El-Hossein, K. A.
2011-02-01
Advanced ceramics of Machinable glass ceramic is attractive material to produce high accuracy miniaturized components for many applications in various industries such as aerospace, electronics, biomedical, automotive and environmental communications due to their wear resistance, high hardness, high compressive strength, good corrosion resistance and excellent high temperature properties. Many research works have been conducted in the last few years to investigate the performance of different machining operations when processing various advanced ceramics. Micro end-milling is one of the machining methods to meet the demand of micro parts. Selecting proper machining parameters are important to obtain good surface finish during machining of Machinable glass ceramic. Therefore, this paper describes the development of predictive model for the surface roughness of Machinable glass ceramic in terms of speed, feed rate by using micro end-milling operation.
Gille, Laure-Anne; Marquis-Favre, Catherine; Morel, Julien
2016-09-01
An in situ survey was performed in 8 French cities in 2012 to study the annoyance due to combined transportation noises. As the European Commission recommends to use the exposure-response relationships suggested by Miedema and Oudshoorn [Environmental Health Perspective, 2001] to predict annoyance due to single transportation noise, these exposure-response relationships were tested using the annoyance due to each transportation noise measured during the French survey. These relationships only enabled a good prediction in terms of the percentages of people highly annoyed by road traffic noise. For the percentages of people annoyed and a little annoyed by road traffic noise, the quality of prediction is weak. For aircraft and railway noises, prediction of annoyance is not satisfactory either. As a consequence, the annoyance equivalents model of Miedema [The Journal of the Acoustical Society of America, 2004], based on these exposure-response relationships did not enable a good prediction of annoyance due to combined transportation noises. Local exposure-response relationships were derived, following the whole computation suggested by Miedema and Oudshoorn [Environmental Health Perspective, 2001]. They led to a better calculation of annoyance due to each transportation noise in the French cities. A new version of the annoyance equivalents model was proposed using these new exposure-response relationships. This model enabled a better prediction of the total annoyance due to the combined transportation noises. These results encourage therefore to improve the annoyance prediction for noise in isolation with local or revised exposure-response relationships, which will also contribute to improve annoyance modeling for combined noises. With this aim in mind, a methodology is proposed to consider noise sensitivity in exposure-response relationships and in the annoyance equivalents model. The results showed that taking into account such variable did not enable to enhance both exposure-response relationships and the annoyance equivalents model. Copyright © 2016 Elsevier Ltd. All rights reserved.
Cogging Torque Reduction Techniques for Spoke-type IPMSM
NASA Astrophysics Data System (ADS)
Bahrim, F. S.; Sulaiman, E.; Kumar, R.; Jusoh, L. I.
2017-08-01
A spoke-type interior permanent magnet synchronous motor (IPMSM) is extending its tentacles in industrial arena due to good flux-weakening capability and high power density. In many of the application, high strength of permanent magnet causes the undesirable effects of high cogging torque that can aggravate performance of the motor. High cogging torque is significantly produced by IPMSM due to the similar length and the effectiveness of the magnetic air-gap. The address of this study is to analyze and compare the cogging torque effect and performance of four common techniques for cogging torque reduction such as skewing, notching, pole pairing and rotor pole pairing. With the aid of 3-D finite element analysis (FEA) by JMAG software, a 6S-4P Spoke-type IPMSM with various rotor-PM configurations has been designed. As a result, the cogging torque effect reduced up to 69.5% for skewing technique, followed by 31.96%, 29.6%, and 17.53% by pole pairing, axial pole pairing and notching techniques respectively.
NASA Astrophysics Data System (ADS)
Manisekaran, T.; Kamaraj, M.; Sharrif, S. M.; Joshi, S. V.
2007-10-01
Hydroturbine steels, such as 13Cr-4Ni martensitic steels, are generally subjected to heavy-erosive wear and loss of efficiency due to solid particulate entrainment in the water. Surface-modified steels have proven to give better performance in terms of erosive wear resistance. In the present study, an attempt is made to investigate the effect of angle of impingement and particle size on slurry-jet erosion behavior of pulsed plasma nitrided and laser hardened 13Cr-4Ni steels. Laser hardening process has shown good performance at all angles of impingement due to martensitic transformation of retained austenite. Plastic deformation mode of material removal was also an evident feature of all laser-hardened surface damage locations. However, pulsed-plasma nitrided steels have exhibited chip formation and micro-cutting mode of erosive wear. Erosion with 150-300 μm size was twice compared to 150 μm size slurry particulates.
He, Jinsong; Chen, J Paul
2014-05-01
Heavy metals contamination has become a global issue of concern due to their higher toxicities, nature of non-biodegradability, high capabilities in bioaccumulation in human body and food chain, and carcinogenicities to humans. A series of researches demonstrate that biosorption is a promising technology for removal of heavy metals from aqueous solutions. Algae serve as good biosorbents due to their abundance in seawater and fresh water, cost-effectiveness, reusability and high metal sorption capacities. This article provides a comprehensive review of recent findings on performances, applications and chemistry of algae (e.g., brown, green and red algae, modified algae and the derivatives) for sequestration of heavy metals. Biosorption kinetics and equilibrium models are reviewed. The mechanisms for biosorption are presented. Biosorption is a complicated process involving ion-exchange, complexation and coordination. Finally the theoretical simulation tools for biosorption equilibrium and kinetics are presented so that the readers can use them for further studies. Copyright © 2014 Elsevier Ltd. All rights reserved.
Electrical characterization of vertically stacked p-FET SOI nanowires
NASA Astrophysics Data System (ADS)
Cardoso Paz, Bruna; Cassé, Mikaël; Barraud, Sylvain; Reimbold, Gilles; Vinet, Maud; Faynot, Olivier; Antonio Pavanello, Marcelo
2018-03-01
This work presents the performance and transport characteristics of vertically stacked p-type MOSFET SOI nanowires (NWs) with inner spacers and epitaxial growth of SiGe raised source/drain. The conventional procedure to extract the effective oxide thickness (EOT) and Shift and Ratio Method (S&R) have been adapted and validated through tridimensional numerical simulations. Electrical characterization is performed for NWs with [1 1 0]- and [1 0 0]-oriented channels, as a function of both fin width (WFIN) and channel length (L). Results show a good electrostatic control and reduced short channel effects (SCE) down to 15 nm gate length, for both orientations. Effective mobility is found around two times higher for [1 1 0]- in comparison to [1 0 0]-oriented NWs due to higher holes mobility contribution in (1 1 0) plan. Improvements obtained on ION/IOFF by reducing WFIN are mainly due to subthreshold slope decrease, once small and none mobility increase is obtained for [1 1 0]- and [1 0 0]-oriented NWs, respectively.
Lubricant reflow after laser heating in heat assisted magnetic recording
NASA Astrophysics Data System (ADS)
Wu, Haoyu; Mendez, Alejandro Rodriguez; Xiong, Shaomin; Bogy, David B.
2015-05-01
In heat assisted magnetic recording (HAMR) technology for hard disk drives, the media will be heated to about 500 °C during the writing process in order to reduce its magnetic coercivity and thus allow data writing with the magnetic head transducers. The traditional lubricants such as Z-dol and Z-tetraol may not be able to perform in such harsh heating conditions due to evaporation, decomposition and thermal depletion. However, some of the lubricant depletion can be recovered due to reflow after a period of time, which can help to reduce the chance of head disk interface failure. In this study, experiments of lubricant thermal depletion and reflow were performed using a HAMR test stage for a Z-tetraol type lubricant. Various lubricant depletion profiles were generated using different laser heating conditions. The lubricant reflow process after thermal depletion was monitored by use of an optical surface analyzer. In addition, a continuum based lubrication model was developed to simulate the lubricant reflow process. Reasonably good agreement between simulations and experiments was achieved.
Scalise, Alessandro; Tartaglione, Caterina; Bolletta, Elisa; Pierangeli, Marina; Di Benedetto, Giovanni
2015-08-01
We report the case of a 50-year-old paraplegic man with a complicated grade III/IV ischiatic pressure sore treated with a propeller flap based on the first perforator of the profunda femoris artery. Our aim was to surgically reconstruct an ischiatic pressure sore in a patient with ankylosis using a fasciocutaneous perforator propeller flap obtained from the posterior region of the thigh. Our decision to perform a profunda femoris artery perforator propeller flap reconstruction was mainly due to the anatomical contiguity of the flap with the site of the lesion and the good quality of the skin harvested from the posterior region of the thigh. The use of the perforator fasciocutaneous flap represents a muscle-sparing technique, providing a better long-term result in surgical reconstruction. The choice of the 180-degree propeller flap was due to its ability to provide a good repair of the pressure ulcer and to pass over the ischiatic prominence in the patient in the forced decubitus position. The operatory course did not present any kind of complication. Using this reconstructive treatment, we have obtained complete coverage of the ischiatic pressure sore.
A tight upper bound for quadratic knapsack problems in grid-based wind farm layout optimization
NASA Astrophysics Data System (ADS)
Quan, Ning; Kim, Harrison M.
2018-03-01
The 0-1 quadratic knapsack problem (QKP) in wind farm layout optimization models possible turbine locations as nodes, and power loss due to wake effects between pairs of turbines as edges in a complete graph. The goal is to select up to a certain number of turbine locations such that the sum of selected node and edge coefficients is maximized. Finding the optimal solution to the QKP is difficult in general, but it is possible to obtain a tight upper bound on the QKP's optimal value which facilitates the use of heuristics to solve QKPs by giving a good estimate of the optimality gap of any feasible solution. This article applies an upper bound method that is especially well-suited to QKPs in wind farm layout optimization due to certain features of the formulation that reduce the computational complexity of calculating the upper bound. The usefulness of the upper bound was demonstrated by assessing the performance of the greedy algorithm for solving QKPs in wind farm layout optimization. The results show that the greedy algorithm produces good solutions within 4% of the optimal value for small to medium sized problems considered in this article.
NASA Technical Reports Server (NTRS)
Komarevskiy,Nikolay; Shklover, Valery; Braginsky, Leonid; Hafner, Christian; Lawson, John W.
2012-01-01
During high-velocity atmospheric entries, space vehicles can be exposed to strong electromagnetic radiation from ionized gas in the shock layer. Glassy carbon (GC) and silicon carbide (SiC) are candidate thermal protection materials due to their high melting point and also their good thermal and mechanical properties. Based on data from shock tube experiments, a significant fraction of radiation at hypersonic entry conditions is in the frequency range from 215 to 415 THz. We propose and analyze SiC and GC photonic structures to increase the reflection of radiation in that range. For this purpose, we performed numerical optimizations of various structures using an evolutionary strategy. Among the considered structures are layered, porous, woodpile, inverse opal and guided-mode resonance structures. In order to estimate the impact of fabrication inaccuracies, the sensitivity of the reflectivity to structural imperfections is analyzed. We estimate that the reflectivity of GC photonic structures is limited to 38% in the aforementioned range, due to material absorption. However, GC material can be effective for photonic reflection of individual, strong spectral line. SiC on the other hand can be used to design a good reflector for the entire frequency range.
Komarevskiy, Nikolay; Shklover, Valery; Braginsky, Leonid; Hafner, Christian; Lawson, John
2012-06-18
During high-velocity atmospheric entries, space vehicles can be exposed to strong electromagnetic radiation from ionized gas in the shock layer. Glassy carbon (GC) and silicon carbide (SiC) are candidate thermal protection materials due to their high melting point and also their good thermal and mechanical properties. Based on data from shock tube experiments, a significant fraction of radiation at hypersonic entry conditions is in the frequency range from 215 to 415 THz. We propose and analyze SiC and GC photonic structures to increase the reflection of radiation in that range. For this purpose, we performed numerical optimizations of various structures using an evolutionary strategy. Among the considered structures are layered, porous, woodpile, inverse opal and guided-mode resonance structures. In order to estimate the impact of fabrication inaccuracies, the sensitivity of the reflectivity to structural imperfections is analyzed. We estimate that the reflectivity of GC photonic structures is limited to 38% in the aforementioned range, due to material absorption. However, GC material can be effective for photonic reflection of individual, strong spectral line. SiC on the other hand can be used to design a good reflector for the entire frequency range.
2014-01-01
In this study, Co/Cu-decorated carbon nanofibers are introduced as novel electrocatalyst for methanol oxidation. The introduced nanofibers have been prepared based on graphitization of poly(vinyl alcohol) which has high carbon content compared to many polymer precursors for carbon nanofiber synthesis. Typically, calcination in argon atmosphere of electrospun nanofibers composed of cobalt acetate tetrahydrate, copper acetate monohydrate, and poly(vinyl alcohol) leads to form carbon nanofibers decorated by CoCu nanoparticles. The graphitization of the poly(vinyl alcohol) has been enhanced due to presence of cobalt which acts as effective catalyst. The physicochemical characterization affirmed that the metallic nanoparticles are sheathed by thin crystalline graphite layer. Investigation of the electrocatalytic activity of the introduced nanofibers toward methanol oxidation indicates good performance, as the corresponding onset potential was small compared to many reported materials; 310 mV (vs. Ag/AgCl electrode) and a current density of 12 mA/cm2 was obtained. Moreover, due to the graphite shield, good stability was observed. Overall, the introduced study opens new avenue for cheap and stable transition metals-based nanostructures as non-precious catalysts for fuel cell applications. PMID:24387682
NASA Technical Reports Server (NTRS)
Komerath, Narayanan M.; Schreiber, Olivier A.
1987-01-01
The wake model was implemented using a VAX 750 and a Microvax II workstation. Online graphics capability using a DISSPLA graphics package. The rotor model used by Beddoes was significantly extended to include azimuthal variations due to forward flight and a simplified scheme for locating critical points where vortex elements are placed. A test case was obtained for validation of the predictions of induced velocity. Comparison of the results indicates that the code requires some more features before satisfactory predictions can be made over the whole rotor disk. Specifically, shed vorticity due to the azimuthal variation of blade loading must be incorporated into the model. Interactions between vortices shed from the four blades of the model rotor must be included. The Scully code for calculating the velocity field is being modified in parallel with these efforts to enable comparison with experimental data. To date, some comparisons with flow visualization data obtained at Georgia Tech were performed and show good agreement for the isolated rotor case. Comparison of time-resolved velocity data obtained at Georgia Tech also shows good agreement. Modifications are being implemented to enable generation of time-averaged results for comparison with NASA data.
Guzel, Tomasz; Mech, Katarzyna; Mazurkiewicz, Michał; Dąbrowski, Bohdan; Lech, Gustaw; Chaber, Andrzej; Słodkowski, Maciej
2016-02-24
Small bowel tumours are rare and comprise less than 2% of all primary gastrointestinal neoplasms. Among these tumours, a leiomyosarcoma belonging to soft tissue sarcomas is extremely rare and accounts for about 1 % of malignant mesenchymal lesions in the gastrointestinal tract. Due to its aggressive nature and slow growth, it is often diagnosed at the late stage when curative treatment is impossible. Authors report a first case of leiomyosarcoma with chronic recurrent ileocaecal intussusception and literature review to analyse diagnosis and treatment features of the ileum mesenchymal tumours. We present a case of an 87-year-old Caucasian man suffering from cramp-like abdominal pain for months. Due to lack of clinical signs and unspecific complaints, a diagnosis was delayed. Despite a detailed in-hospital examination, a proper diagnosis was established as late as during an operation. The patient was treated by surgery with good results. An uncommon laparoscopic resection of the small bowel with a tumour was performed. A histopathological investigation confirmed a very rare mesenchymal lesion of the distal ileum. The patient is under control with no recurrence for 1 year of the follow-up period. Reported case indicates that a usually asymptomatic tumour can cause uncommon chronic recurrent ileus signs. CT and MRI scans are investigation of choice in such cases, but they are sometimes inconclusive. It might be worth highlighting the good results of laparoscopic leiomyosarcoma lesion resection with a very good outcome.
Gel polymer electrolytes based on nanofibrous polyacrylonitrile–acrylate for lithium batteries
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kim, Dul-Sun; Woo, Jang Chang; Youk, Ji Ho, E-mail: youk@inha.ac.kr
2014-10-15
Graphical abstract: - Highlights: • Nanofibrous polyacrylonitrile–acrylate membranes were prepared by electrospinning. • Trimethylolpropane triacrylate was used as a crosslinking agent of fibers. • The GPE based on PAN–acrylate (1/0.5) showed good electrochemical properties. - Abstract: Nanofibrous membranes for gel polymer electrolytes (GPEs) were prepared by electrospinning a mixture of polyacrylonitrile (PAN) and trimethylolpropane triacrylate (TMPTA) at weight ratios of 1/0.5 and 1/1. TMPTA is used to achieve crosslinking of fibers thereby improving mechanical strength. The average fiber diameters increased with increasing TMPTA concentration and the mechanical strength was also improved due to the enhanced crosslinking of fibers. GPEs basedmore » on electrospun membranes were prepared by soaking them in a liquid electrolyte of 1 M LiPF{sub 6} in ethylene carbonate (EC)/dimethyl carbonate (DMC) (1:1, v/v). The electrolyte uptake and ionic conductivity of GPEs based on PAN and PAN–acrylate (weight ratio; 1/1 and 1/0.5) were investigated. Ionic conductivity of GPEs based on PAN–acrylate was the highest for PAN/acrylate (1/0.5) due to the proper swelling of fibers and good affinity with liquid electrolyte. Both GPEs based on PAN and PAN–acrylate membranes show good oxidation stability, >5.0 V vs. Li/Li{sup +}. Cells with GPEs based on PAN–acrylate (1/0.5) showed remarkable cycle performance with high initial discharge capacity and low capacity fading.« less
Goodness-of-Fit Tests for Generalized Normal Distribution for Use in Hydrological Frequency Analysis
NASA Astrophysics Data System (ADS)
Das, Samiran
2018-04-01
The use of three-parameter generalized normal (GNO) as a hydrological frequency distribution is well recognized, but its application is limited due to unavailability of popular goodness-of-fit (GOF) test statistics. This study develops popular empirical distribution function (EDF)-based test statistics to investigate the goodness-of-fit of the GNO distribution. The focus is on the case most relevant to the hydrologist, namely, that in which the parameter values are unidentified and estimated from a sample using the method of L-moments. The widely used EDF tests such as Kolmogorov-Smirnov, Cramer von Mises, and Anderson-Darling (AD) are considered in this study. A modified version of AD, namely, the Modified Anderson-Darling (MAD) test, is also considered and its performance is assessed against other EDF tests using a power study that incorporates six specific Wakeby distributions (WA-1, WA-2, WA-3, WA-4, WA-5, and WA-6) as the alternative distributions. The critical values of the proposed test statistics are approximated using Monte Carlo techniques and are summarized in chart and regression equation form to show the dependence of shape parameter and sample size. The performance results obtained from the power study suggest that the AD and a variant of the MAD (MAD-L) are the most powerful tests. Finally, the study performs case studies involving annual maximum flow data of selected gauged sites from Irish and US catchments to show the application of the derived critical values and recommends further assessments to be carried out on flow data sets of rivers with various hydrological regimes.
Li, Hongjia; Le, Qiqi; Liu, Shanshan; Zong, Shaoqi; Zheng, Leizhen; Hou, Fenggang
2016-01-01
A variety of triple antiemetic regimens are being used to prevent cisplatin-based chemotherapy induced delayed emesis and nausea in cancer patients. We performed a network meta-analysis to compare the efficacies of the different regimens. Electronic searches of the PubMed, Cochrane Library and MEDLINE databases were performed to identify randomized controlled trials, and data were analyzed using JAGS, Stata 14.0 and R project. The primary outcome was a complete response (CR). The secondary outcomes were no vomiting (NV) and no nausea (NN). Among the 398 studies identified, 10 were eligible and included, providing data on nine regimens. In the CR analysis, the absolute rank of netupitant + palonosetron + dexamethasone (NEPA) was 0.8579. In the NV and NN analyses, NEPA's absolute ranks were 0.8631 and 0.7902, respectively. The compliance of patients treated with rolapitant + granisetron + dexamethasone (RGD) was the best due to a low incidence of adverse events, and good compliance was also observed with NEPA. It was difficult to achieve good compliance with aprepitant + granisetron + dexamethasone (AGD). Overall, NEPA was the best regimen, and aprepitant + ondansetron + dexamethasone (AOD) is also worthy of recommendation because of its low cost and good effect. For patients with severe constipation, hiccups, asthenia and/or delayed nausea, RGD is worthy of consideration. PMID:27015550
A correlation between micro- and nano-indentation on materials irradiated by high-energy heavy ions
NASA Astrophysics Data System (ADS)
Yang, Yitao; Zhang, Chonghong; Ding, Zhaonan; Su, Changhao; Yan, Tingxing; Song, Yin; Cheng, Yuguang
2018-01-01
Hardness testing is an efficient means of assessing the mechanical properties of materials due to the small sampling volume requirement. Previous studies have established the correlation between flow stress and Vickers hardness. However, the damage layer produced by ions irradiation with low energy is too thin to perform Vickers hardness test, which is usually measured by nano-indentation. Therefore, it is necessary to correlate the Vickers hardness and nano-hardness for the convenience of assessing mechanical properties of materials under irradiation. In this study, various materials (pure nickel, nickel base alloys and oxide dispersion strengthened steel) were irradiated with high-energy heavy ions to different damage levels. After irradiation, micro- and nano-indentation were performed to characterize the change in hardness. Due to indentation size effect (ISE), the hardness was dependent of load or depth. Therefore, Nix-Gao model was used to obtain the hardness without ISE (Hv0 and Hnano_0). The determined Hv0 was plotted as a function of the corresponding Hnano_0, then a good linear relation was found between Vickers hardness and nano-hardness, and a coefficient was determined to be 81.0 ± 10.5, namely, Hv 0 = 81.0Hnano _ 0 (Hv0 with unit of kgf/mm2, Hnano_0 with unit of GPa). This correlation was based on the data from various materials, therefore it was independent of materials. Based on the established correlation and nano-indentation results, the change fraction in yield stress of Inconel 718 and pure Ni with ion irradiation was compared with that with neutron irradiation. The data of Inconel 718 with heavy ion irradiation was in good agreement with the data with neutron irradiation, which was a good demonstration for the validation of the established correlation. However, a distinctive difference in change fraction of yield stress was seen for pure Ni under heavy ion irradiation and neutron irradiation, which was attributed to the difference in samples (single crystal and polycrystalline).
Concurrent changes in aggregation and swelling of coal particles in solvents
DOE Office of Scientific and Technical Information (OSTI.GOV)
Nishioka, M.
1995-12-31
A new method of coal swelling has been developed tinder the condition of low coal concentrations with continuous mixing of coal and solvent. The change in particle size distributions by a laser scattering procedure was used for the evaluation of coal swelling. Particle size distributions in good and poor solvents were nearly equal, but reversibly changed in good solvents from time to time. The effects of solubles and coal concentrations on the distributions were small. It was concluded that aggregate d coal particles disaggregate in good solvents, and that an increase in the particle size distribution due to swelling inmore » good solvents are compensated by a decrease in the particle size due to disaggregation. Therefore, the behavior of coal particles in solvents is controlled by aggregation in addition to coal swelling. This implies that an increase in the particle size due to coal swelling in actual processes is not so large as expected by the results obtained from the conventional coal swelling methods.« less
Contractive tension force stack actuator based on soft dielectric EAP
NASA Astrophysics Data System (ADS)
Kovacs, Gabor; Düring, Lukas
2009-03-01
Among the electronic polymers EAPs especially the dielectric elastomers are functional materials that have promising potential as muscle-like actuators due to their inherent compliancy and good overall performance. The combination of huge active deformations, high energy densities, good efficiencies and fast response is unique to dielectric elastomers. Furthermore, they are lightweight, have a simple structure and can be easily tailored to various applications. Up to now most scientific research work has been focused on the planar expanding actuation mode due to the fact that the commercially available acrylic material VHB 4910 (3M) can easily be processed to planar actuators and has demonstrated very high actuation performance when pre-strained. Many different actuator designs have been developed and tested which expands in plane when voltage is applied and shrinks back as soon as the applied charges are removed from the electrodes. Obviously the contractive operation mode at activation is required for a wide range of application. Due to the principle of operation of soft DE EAP, mainly two directions to performed work against external loads are possible. Beside of the commonly used expanding actuation in planar direction the contractile actuation in thickness direction of the DE film represents a very promising option in the multilayer configuration. First approaches have been presented by the folded actuator design and by the multilayer tactile display device. In this study a novel approach for active structures driven by soft dielectric EAP is presented, which can perform contractive displacements at external tensile load. The device is composed of an array of equal segments, where the dielectric films are arranged in a pile-up configuration. In order to maintain satisfying structural integrity when external tension load is applied special attention was paid to the compliant electrode design which takes a central importance concerning the force transmission capability between each layer of the actuator. Due to the stack configuration of the actuator the commonly used and pre-strained acrylic film was replaced by the stress-free IPN modified acrylic film in order to eliminate the need for external pre-strain-supporting structures. Introductorily, the specific problems on conventional expanding actuators are discussed and the aims for contractive tension force actuators are specified. Then some structural design parameters are addressed in order to achieve a high rate of yield and reliable working principle. In the main part of the study the manufacturing process of the actuators and some measurement results and experiences are discussed in detail.
Forecasting electricity usage using univariate time series models
NASA Astrophysics Data System (ADS)
Hock-Eam, Lim; Chee-Yin, Yip
2014-12-01
Electricity is one of the important energy sources. A sufficient supply of electricity is vital to support a country's development and growth. Due to the changing of socio-economic characteristics, increasing competition and deregulation of electricity supply industry, the electricity demand forecasting is even more important than before. It is imperative to evaluate and compare the predictive performance of various forecasting methods. This will provide further insights on the weakness and strengths of each method. In literature, there are mixed evidences on the best forecasting methods of electricity demand. This paper aims to compare the predictive performance of univariate time series models for forecasting the electricity demand using a monthly data of maximum electricity load in Malaysia from January 2003 to December 2013. Results reveal that the Box-Jenkins method produces the best out-of-sample predictive performance. On the other hand, Holt-Winters exponential smoothing method is a good forecasting method for in-sample predictive performance.
Simulation-based performance analysis of EC-Earth 3.2.0 using Dimemas
NASA Astrophysics Data System (ADS)
Yepes Arbós, Xavier; César Acosta Cobos, Mario; Serradell Maronda, Kim; Sanchez Lorente, Alicia; Doblas Reyes, Francisco Javier
2017-04-01
Earth System Models (ESMs) are complex applications executed in supercomputing facilities due to their high demand on computing resources. However, not all these models perform a good resources usage and the energy efficiency can be well below a minimum acceptable. One example is EC-Earth, a global coupled climate model which integrates different component models to simulate the Earth system. The two main components used in this analysis are IFS as atmospheric model and NEMO as ocean model, both coupled via the OASIS3-MCT coupler. Preliminary results proved that EC-Earth does not have a good computational performance. For example, the scalability of this model using the T255L91 grid with 512 MPI processes for IFS and the ORCA1L75 grid with 128 MPI processes for NEMO achieves 40.3 of speedup. This means that the 81.2% of the resources are wasted. Therefore, it is necessary a performance analysis to find the bottlenecks of the model and thus, determine the most appropriate optimization techniques. Using traces of the model collected with profiling tools such as Extrae, Paraver and Dimemas, allow us to simulate the model behaviour on a configurable parallel platform and extrapolate the impact of hardware changes in the performance of EC-Earth. In this document we propose a state-of-art procedure which makes possible to evaluate the different characteristics of climate models in a very efficient way. Accordingly, the performance of EC-Earth in different scenarios, namely assuming an ideal machine, model sensitivity and limiting model due to coupling has been shown. By simulating these scenarios, we realized that each model has different characteristics. With the ideal machine, we have seen that there are some sources of inefficiency: about a 20.59% of the execution time is communication; and there are workload imbalances produced by data dependences both between IFS and NEMO and within each model. In addition, in the model sensitivity simulations, we have described the types of messages and detected data dependencies. In IFS, we have observed that latency affects the coupling between models due to a large amount of small communications, whereas bandwidth affects another region of the code with a few big messages. In NEMO, results show that the simulated latencies and bandwidths only affect slightly to its execution time. However, it has data dependencies solved inefficiently and workload imbalances. The last simulation performed to detect the slowest model due to coupling has revealed that IFS is slower than NEMO. Moreover, there is not enough bandwidth to transfer all the data in IFS, whereas in NEMO there is almost no contention. This study is useful to improve the computational efficiency of the model, adapt it to support ultra-high resolution (UHR) experiments and future exascale supercomputers, and help code developers to design new algorithms more machine-independent.
Zhang, Yunlu; Gao, Qiuming; Lin, Zhi; Zhang, Tao; Xu, Jiandong; Tan, Yanli; Tian, Weiqian; Jiang, Lei
2014-01-01
Metal organic framework (MOF) materials have attracted great attention due to their well-ordered and controllable pores possessing of prominent potentials for gas molecule sorption and separation performances. Organizing the MOF crystals to a continuous membrane with a certain scale will better exhibit their prominent potentials. Reports in recent years concentrate on well grown MOF membranes on specific substrates. Free standing MOF membranes could have more important applications since they are independent from the substrates. However, the method to prepare such a membrane has been a great challenge because good mechanical properties and stabilities are highly required. Here, we demonstrate a novel and facile technique for preparing the free standing membrane with a size as large as centimeter scale. The substrate we use proved itself not only a good skeleton but also an excellent precursor to fulfill the reaction. This kind of membrane owns a strong mechanical strength, based on the fact that it is much thinner than the composite membranes grown on substrates and it could exhibit good property of gas separation. PMID:24821299
Fujiwara, Shinichi; Hasuike, Yasunori; Fukuchi, Nariaki; Hayashi, Nobuyasu; Kida, Hiroyuki; Tsujie, Masaki; Yoshida, Tetsuya; Ebisui, Chikara; Sakita, Isao; Fujimoto, Takayoshi
2005-10-01
We report a case of cholangio celluler carcinoma (CCC) with a good quality of life, in spite of the recurrence of peritoneum and portal hepatic lymph nodes (PHLN), due to the combination therapy that consisted of hepatic arterial infusion, systemic chemotherapy, radiation therapy and an insertion of a metallic stent into the bile duct. The patient was a 61-year-old man. Left hepatectomy was done due to multiple CCC. For the purpose of preventing the recurrence of CCC in residual liver, we performed an arterial infusion therapy. Ten months later, metastases to peritoneum and portal hepatic lymph nodes were found, so the resection of the peritoneum was performed, and cells in ascites were defined to be positive with cytology. After 2 years from the first operation, the size of portal hepatic lymph nodes had grown and both the billilbin and tumor marker levels had increased, so we started systemic chemotherapy, radiation therapy and insertion of a metallic stent into the bile duct. The tumor marker level decreased in a short time. Consequently, we inserted a metallic stent into the bile duct and radiation therapy was performed. Until the patient's death due to peritonitis carcinomatosa, the recurrence in residual liver occurred only once in three years after the first operation, and portal hepatic lymph nodes did not grow for two years after the recurrence.
Long-Wavelength 640 x 486 GaAs/AlGaAs Quantum Well Infrared Photodetector Snap-Shot Camera
NASA Technical Reports Server (NTRS)
Gunapala, Sarath D.; Bandara, Sumith V.; Liu, John K.; Hong, Winn; Sundaram, Mani; Maker, Paul D.; Muller, Richard E.; Shott, Craig A.; Carralejo, Ronald
1998-01-01
A 9-micrometer cutoff 640 x 486 snap-shot quantum well infrared photodetector (QWIP) camera has been demonstrated. The performance of this QWIP camera is reported including indoor and outdoor imaging. The noise equivalent differential temperature (NE.deltaT) of 36 mK has been achieved at 300 K background with f/2 optics. This is in good agreement with expected focal plane array sensitivity due to the practical limitations on charge handling capacity of the multiplexer, read noise, bias voltage, and operating temperature.
Vortex algebra by multiply cascaded four-wave mixing of femtosecond optical beams.
Hansinger, Peter; Maleshkov, Georgi; Garanovich, Ivan L; Skryabin, Dmitry V; Neshev, Dragomir N; Dreischuh, Alexander; Paulus, Gerhard G
2014-05-05
Experiments performed with different vortex pump beams show for the first time the algebra of the vortex topological charge cascade, that evolves in the process of nonlinear wave mixing of optical vortex beams in Kerr media due to competition of four-wave mixing with self-and cross-phase modulation. This leads to the coherent generation of complex singular beams within a spectral bandwidth larger than 200nm. Our experimental results are in good agreement with frequency-domain numerical calculations that describe the newly generated spectral satellites.
GO-induced assembly of gelatin toward stacked layer-like porous carbon for advanced supercapacitors
NASA Astrophysics Data System (ADS)
Zhang, Xiaomeng; Jiao, Yanqing; Sun, Li; Wang, Lei; Wu, Aiping; Yan, Haijing; Meng, Meichen; Tian, Chungui; Jiang, Baojiang; Fu, Honggang
2016-01-01
Layer-like nanocarbons with high surface area and good conductivity are promising materials for supercapacitors due to their good ability for effective charge-transfer and mass-transfer. In this paper, stacked layer-like porous carbon containing RGO (reduced graphene oxides) (LPCG) was constructed via the GO-induced assembly of gelatin followed by carbonization and activation processes. Under suitable conditions, LPCG-based materials with a thickness of about 100 nm and a high specific surface area (up to 1476 m2 g-1) could be obtained. In the materials, the closed combination of RGO and porous carbon can be observed, which is favourable for the development of the synergistic effects of both components. The presence of GO can not only enhance the conductivity of LPCG-based materials, but also is essential for the formation of a thin carbon sheet with a stacked structure. Otherwise, the plate-like, non-stacked carbon with a thickness of about 500 nm could be formed in the absence of RGO. The porous structure along with the presence of RGO allows rapid charge-transfer and easy access and diffusion of electrolyte ions. As a result, the materials exhibited a high discharge specific capacitance (455 F g-1 at 0.5 A g-1, 366 F g-1 at 1 A g-1), good rate capability (221 F g-1 at density 30 A g-1) and good cycling stability. In aqueous electrolytes, the energy density could be up to 9.32 W h kg-1 at a relatively low power density of 500 W kg-1 with a good cycling stability (>96% over 5000 cycles). It was found that (1) the rational combination of RGO and porous carbon is essential for enhancing the capacitance performance and improving the cycling stability and (2) the high conductivity is favorable for improving the rate performance of the materials. The LPCG-based materials have extensive potential for practical applications in energy storage and conversion devices.Layer-like nanocarbons with high surface area and good conductivity are promising materials for supercapacitors due to their good ability for effective charge-transfer and mass-transfer. In this paper, stacked layer-like porous carbon containing RGO (reduced graphene oxides) (LPCG) was constructed via the GO-induced assembly of gelatin followed by carbonization and activation processes. Under suitable conditions, LPCG-based materials with a thickness of about 100 nm and a high specific surface area (up to 1476 m2 g-1) could be obtained. In the materials, the closed combination of RGO and porous carbon can be observed, which is favourable for the development of the synergistic effects of both components. The presence of GO can not only enhance the conductivity of LPCG-based materials, but also is essential for the formation of a thin carbon sheet with a stacked structure. Otherwise, the plate-like, non-stacked carbon with a thickness of about 500 nm could be formed in the absence of RGO. The porous structure along with the presence of RGO allows rapid charge-transfer and easy access and diffusion of electrolyte ions. As a result, the materials exhibited a high discharge specific capacitance (455 F g-1 at 0.5 A g-1, 366 F g-1 at 1 A g-1), good rate capability (221 F g-1 at density 30 A g-1) and good cycling stability. In aqueous electrolytes, the energy density could be up to 9.32 W h kg-1 at a relatively low power density of 500 W kg-1 with a good cycling stability (>96% over 5000 cycles). It was found that (1) the rational combination of RGO and porous carbon is essential for enhancing the capacitance performance and improving the cycling stability and (2) the high conductivity is favorable for improving the rate performance of the materials. The LPCG-based materials have extensive potential for practical applications in energy storage and conversion devices. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr07857a
The rewarding value of good motor performance in the context of monetary incentives.
Lutz, Kai; Pedroni, Andreas; Nadig, Karin; Luechinger, Roger; Jäncke, Lutz
2012-07-01
Whether an agent receives positive task feedback or a monetary reward, neural activity in their striatum increases. In the latter case striatal activity reflects extrinsic reward processing, while in the former, striatal activity reflects the intrinsically rewarding effects of performing well. There can be a "hidden cost of reward", which is a detrimental effect of extrinsic on intrinsic reward value. This raises the question how these two types of reward interact. To address this, we applied a monetary incentive delay task: in all trials participants received feedback depending on their performance. In half of the trials they could additionally receive monetary reward if they performed well. This resulted in high performance trials, which were monetarily rewarded and high performance trials that were not. This made it possible to dissociate the neural correlates of performance feedback from the neural correlates of monetary reward that comes with high performance. Performance feedback alone elicits activation increases in the ventral striatum. This activation increases due to additional monetary reward. Neural response in the dorsal striatum on the other hand is only significantly increased by feedback when a monetary incentive is present. The quality of performance does not significantly influence dorsal striatum activity. In conclusion, our results indicate that the dorsal striatum is primarily sensitive to optional or actually received external rewards, whereas the ventral striatum may be coding intrinsic reward due to positive performance feedback. Thus the ventral striatum is suggested to be involved in the processing of intrinsically motivated behavior. Copyright © 2012 Elsevier Ltd. All rights reserved.
Mane, Sandeep B; Sutanto, Albertus Adrian; Cheng, Chih-Fu; Xie, Meng-Yu; Chen, Chieh-I; Leonardus, Mario; Yeh, Shih-Chieh; Beyene, Belete Bedemo; Diau, Eric Wei-Guang; Chen, Chin-Ti; Hung, Chen-Hsiung
2017-09-20
The high performance of the perovskite solar cells (PSCs) cannot be achieved without a layer of efficient hole-transporting materials (HTMs) to retard the charge recombination and transport the photogenerated hole to the counterelectrode. Herein, we report the use of boryl oxasmaragdyrins (SM01, SM09, and SM13), a family of aromatic core-modified expanded porphyrins, as efficient hole-transporting materials (HTMs) for perovskite solar cells (PSCs). These oxasmaragdyrins demonstrated complementary absorption spectra in the low-energy region, good redox reversibility, good thermal stability, suitable energy levels with CH 3 NH 3 PbI 3 perovskite, and high hole mobility. A remarkable power conversion efficiency of 16.5% (V oc = 1.09 V, J sc = 20.9 mA cm -2 , fill factor (FF) = 72%) is achieved using SM09 on the optimized PSCs device employing a planar structure, which is close to that of the state-of-the-art hole-transporting materials (HTMs), spiro-OMeTAD of 18.2% (V oc = 1.07 V, J sc = 22.9 mA cm -2 , FF = 74%). In contrast, a poor photovoltaic performance of PSCs using SM01 is observed due to the interactions of terminal carboxylic acid functional group with CH 3 NH 3 PbI 3 .
NASA Astrophysics Data System (ADS)
Deng, Yuanfu; Xu, Hui; Bai, Zhaowen; Huang, Baoling; Su, Jingyang; Chen, Guohua
2015-12-01
Lithium-sulfur batteries show fascinating potential for advanced energy system due to their high specific capacity, low-cost, and environmental benignity. However, their wide applications have been plagued by low coulombic efficiency, fast capacity fading and poor rate performance. Herein, a facile method for preparation of S@PDA (PDA = polydopamine) composites with core-shell structure and good electrochemical performance as well as the First-Principles calculations on the interactions of PDA and polysulfides are reported. Taking the advantages of the core-shell structure with porous sulfur core, the high mechanical flexibility of PDA for accommodating the volumetric variation during the discharge/charge processes, the good lithium ion conductivity and the strong chemical interactions between the nitrogen/oxygen atoms with lone electron pair and lithium polysulfides for alleviating their dissolution, the S@PDA composites exhibit high discharge capacities at different current densities (1048 and 869 mAh g-1 at 0.2 and 0.8 A g-1, respectively) and excellent capacity retention capability. A capacity decay as low as 0.021% per cycle and an average coulombic efficiency of 98.5% is observed over a long-term cycling of 890 cycles at 0.8 A g-1. The S@PDA electrode has great potential as a low-cost cathode in high energy Li-S batteries.
Xiong, Wei; Gao, Yongsheng; Wu, Xu; Hu, Xuan; Lan, Danni; Chen, Yangyang; Pu, Xuli; Zeng, Yan; Su, Jun; Zhu, Zhihong
2014-01-01
Novel biological carbon materials with highly ordered microstructure and large pore volume have caused great interest due to their multifunctional properties. Herein, we report the preparation of an interconnected porous carbon material by carbonizing the organic matrix of mollusc shell. The obtained three-dimensional carbon skeleton consists of hexangular and tightly arranged channels, which endow it with efficient electrolyte penetration and fast electron transfer, enable the mollusc shell based macroporous carbon material (MSBPC) to be an excellent conductive scaffold for supercapacitor electrodes. By growing NiCo2O4 nanowires on the obtained MSBPC, NiCo2O4/MSBPC composites were synthesized. When used on supercapacitor electrode, it exhibited anomalously high specific capacitance (∼1696 F/g), excellent rate performance (with the capacity retention of 58.6% at 15 A/g) and outstanding cycling stability (88% retention after 2000 cycles). Furthermore, an all-solid-state symmetric supercapacitor was also assembled based on this NiCo2O4/MSBPC electrode and showed good electrochemical performance with an energy density of 8.47 Wh/kg at 1 A/g, good stability over 10000 cycles. And we believe that more potential applications beyond energy storage can be developed based on this MSBPC.
Development of a multicomponent force and moment balance for water tunnel applications, volume 2
NASA Technical Reports Server (NTRS)
Suarez, Carlos J.; Malcolm, Gerald N.; Kramer, Brian R.; Smith, Brooke C.; Ayers, Bert F.
1994-01-01
The principal objective of this research effort was to develop a multicomponent strain gauge balance to measure forces and moments on models tested in flow visualization water tunnels. Static experiments (which are discussed in Volume 1 of this report) were conducted, and the results showed good agreement with wind tunnel data on similar configurations. Dynamic experiments, which are the main topic of this Volume, were also performed using the balance. Delta wing models and two F/A-18 models were utilized in a variety of dynamic tests. This investigation showed that, as expected, the values of the inertial tares are very small due to the low rotating rates required in a low-speed water tunnel and can, therefore, be ignored. Oscillations in pitch, yaw and roll showed hysteresis loops that compared favorably to data from dynamic wind tunnel experiments. Pitch-up and hold maneuvers revealed the long persistence, or time-lags, of some of the force components in response to the motion. Rotary-balance experiments were also successfully performed. The good results obtained in these dynamic experiments bring a whole new dimension to water tunnel testing and emphasize the importance of having the capability to perform simultaneous flow visualization and force/moment measurements during dynamic situations.
NASA Astrophysics Data System (ADS)
Lacava, C.; Liu, Z.; Thomson, D.; Ke, Li; Fedeli, J. M.; Richardson, D. J.; Reed, G. T.; Petropoulos, P.
2016-02-01
Communication traffic grows relentlessly in today's networks, and with ever more machines connected to the network, this trend is set to continue for the foreseeable future. It is widely accepted that increasingly faster communications are required at the point of the end users, and consequently optical transmission plays a progressively greater role even in short- and medium-reach networks. Silicon photonic technologies are becoming increasingly attractive for such networks, due to their potential for low cost, energetically efficient, high-speed optical components. A representative example is the silicon-based optical modulator, which has been actively studied. Researchers have demonstrated silicon modulators in different types of structures, such as ring resonators or slow light based devices. These approaches have shown remarkably good performance in terms of modulation efficiency, however their operation could be severely affected by temperature drifts or fabrication errors. Mach-Zehnder modulators (MZM), on the other hand, show good performance and resilience to different environmental conditions. In this paper we present a CMOS-compatible compact silicon MZM. We study the application of the modulator to short-reach interconnects by realizing data modulation using some relevant advanced modulation formats, such as 4-level Pulse Amplitude Modulation (PAM-4) and Discrete Multi-Tone (DMT) modulation and compare the performance of the different systems in transmission.
Ma, Lin; Xu, Yubin
2015-01-01
Green WLAN is a promising technique for accessing future indoor Internet services. It is designed not only for high-speed data communication purposes but also for energy efficiency. The basic strategy of green WLAN is that all the access points are not always powered on, but rather work on-demand. Though powering off idle access points does not affect data communication, a serious asymmetric matching problem will arise in a WLAN indoor positioning system due to the fact the received signal strength (RSS) readings from the available access points are different in their offline and online phases. This asymmetry problem will no doubt invalidate the fingerprint algorithm used to estimate the mobile device location. Therefore, in this paper we propose a green WLAN indoor positioning system, which can recover RSS readings and achieve good localization performance based on singular value thresholding (SVT) theory. By solving the nuclear norm minimization problem, SVT recovers not only the radio map, but also online RSS readings from a sparse matrix by sensing only a fraction of the RSS readings. We have implemented the method in our lab and evaluated its performances. The experimental results indicate the proposed system could recover the RSS readings and achieve good localization performance. PMID:25587977
Numerical Study of Aeroacoustic Sound on Performance of Bladeless Fan
NASA Astrophysics Data System (ADS)
Jafari, Mohammad; Sojoudi, Atta; Hafezisefat, Parinaz
2017-03-01
Aeroacoustic performance of fans is essential due to their widespread application. Therefore, the original aim of this paper is to evaluate the generated noise owing to different geometric parameters. In current study, effect of five geometric parameters was investigated on well performance of a Bladeless fan. Airflow through this fan was analyzed simulating a Bladeless fan within a 2 m×2 m×4 m room. Analysis of the flow field inside the fan and evaluating its performance were obtained by solving conservations of mass and momentum equations for aerodynamic investigations and FW-H noise equations for aeroacoustic analysis. In order to design Bladeless fan Eppler 473 airfoil profile was used as the cross section of this fan. Five distinct parameters, namely height of cross section of the fan, outlet angle of the flow relative to the fan axis, thickness of airflow outlet slit, hydraulic diameter and aspect ratio for circular and quadratic cross sections were considered. Validating acoustic code results, we compared numerical solution of FW-H noise equations for NACA0012 with experimental results. FW-H model was selected to predict the noise generated by the Bladeless fan as the numerical results indicated a good agreement with experimental ones for NACA0012. To validate 3-D numerical results, the experimental results of a round jet showed good agreement with those simulation data. In order to indicate the effect of each mentioned parameter on the fan performance, SPL and OASPL diagrams were illustrated.
Sader, John E; Yousefi, Morteza; Friend, James R
2014-02-01
Thermal noise spectra of nanomechanical resonators are used widely to characterize their physical properties. These spectra typically exhibit a Lorentzian response, with additional white noise due to extraneous processes. Least-squares fits of these measurements enable extraction of key parameters of the resonator, including its resonant frequency, quality factor, and stiffness. Here, we present general formulas for the uncertainties in these fit parameters due to sampling noise inherent in all thermal noise spectra. Good agreement with Monte Carlo simulation of synthetic data and measurements of an Atomic Force Microscope (AFM) cantilever is demonstrated. These formulas enable robust interpretation of thermal noise spectra measurements commonly performed in the AFM and adaptive control of fitting procedures with specified tolerances.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Sader, John E., E-mail: jsader@unimelb.edu.au; Yousefi, Morteza; Friend, James R.
2014-02-15
Thermal noise spectra of nanomechanical resonators are used widely to characterize their physical properties. These spectra typically exhibit a Lorentzian response, with additional white noise due to extraneous processes. Least-squares fits of these measurements enable extraction of key parameters of the resonator, including its resonant frequency, quality factor, and stiffness. Here, we present general formulas for the uncertainties in these fit parameters due to sampling noise inherent in all thermal noise spectra. Good agreement with Monte Carlo simulation of synthetic data and measurements of an Atomic Force Microscope (AFM) cantilever is demonstrated. These formulas enable robust interpretation of thermal noisemore » spectra measurements commonly performed in the AFM and adaptive control of fitting procedures with specified tolerances.« less
Mitsukawa, Nobuyuki; Saiga, Atsuomi; Morishita, Tadashi; Satoh, Kaneshige
2014-07-01
Patients with bilateral cleft lips and palates have premaxillary protrusion and characteristic jaw deformities involving three-dimensional malposition of the premaxilla and bilateral maxillary bone segments. This study examined patients with bilateral cleft lips and palates who had deviation and hypoplasia of the premaxillas and bilateral maxillary segments. Before bone grafting, the patients were treated with special distraction performed separately for each bone segment using a halo-type external device. This report describes this novel treatment method which produced good results. The subjects were five patients with severe jaw deformities due to bilateral cleft lip and palate. They were treated with maxillary Le Fort I osteotomy and subsequent distraction performed separately for each bone segment using a halo device. In three of five patients, premaxillary osteotomy was not performed, and osteotomy and distraction were performed only for the right and left lateral segments with severe hypoplasia. All patients achieved distraction close to the desired amount. The widths of the alveolar clefts were narrowed, and satisfactory occlusion and maxillary arch form were achieved. After the surgery, three of five patients underwent bone grafting for bilateral alveolar cleft defects and the bone graft survival was satisfactory. This method had many benefits, including narrowing of alveolar clefts, improvement of maxillary hypoplasia, and achievement of a good maxillary arch form. In addition, subsequent bone grafting for alveolar cleft defects was beneficial, dental prostheses were unnecessary, and frequency of surgery and surgical invasiveness were reduced. This method is a good surgical procedure that should be considered for patients with bilateral cleft lips and palates who have premaxillary protrusion and hypoplasia of the right and left lateral segments. Copyright © 2013 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.
He, Penghui; Jiang, Congbiao; Lan, Linfeng; Sun, Sheng; Li, Yizhi; Gao, Peixiong; Zhang, Peng; Dai, Xingqiang; Wang, Jian; Peng, Junbiao; Cao, Yong
2018-05-22
Light-emitting field-effect transistors (LEFETs) have attained great attention due to their special characteristics of both the switching capacity and the electroluminescence capacity. However, high-performance LEFETs with high mobility, high brightness, and high efficiency have not been realized due to the difficulty in developing high electron and hole mobility materials with suitable band structures. In this paper, quantum dot hybrid LEFETs (QD-HLEFETs) combining high-luminous-efficiency quantum dots (QDs) and a solution-processed scandium-incorporated indium oxide (Sc:In 2 O 3 ) semiconductor were demonstrated. The red QD-HLEFET showed high electrical and optical performance with an electron mobility of 0.8 cm 2 V -1 s -1 , a maximum brightness of 13 400 cd/m 2 , and a maximum external quantum efficiency of 8.7%. The high performance of the QD-HLEFET is attributed to the good energy band matching between Sc:In 2 O 3 and QDs and the balanced hole and electron injection (less exciton nonradiative recombination). In addition, incorporation of Sc into In 2 O 3 can suppress the oxygen vacancy and free carrier generation and brings about excellent current and optical modulation (the on/off current ratio is 10 5 and the on/off brightness ratio is 10 6 ).
High Temperature Carbonized Grass as a High Performance Sodium Ion Battery Anode.
Zhang, Fang; Yao, Yonggang; Wan, Jiayu; Henderson, Doug; Zhang, Xiaogang; Hu, Liangbing
2017-01-11
Hard carbon is currently considered the most promising anode candidate for room temperature sodium ion batteries because of its relatively high capacity, low cost, and good scalability. In this work, switchgrass as a biomass example was carbonized under an ultrahigh temperature, 2050 °C, induced by Joule heating to create hard carbon anodes for sodium ion batteries. Switchgrass derived carbon materials intrinsically inherit its three-dimensional porous hierarchical architecture, with an average interlayer spacing of 0.376 nm. The larger interlayer spacing than that of graphite allows for the significant Na ion storage performance. Compared to the sample carbonized under 1000 °C, switchgrass derived carbon at 2050 °C induced an improved initial Coulombic efficiency. Additionally, excellent rate capability and superior cycling performance are demonstrated for the switchgrass derived carbon due to the unique high temperature treatment.
[Pedal bypass using venous allograft].
Pluháčková, H; Staffa, R; Konečný, Z; Kříž, Z; Vlachovský, R
Pedal or distal crural bypass surgery for limb salvage is a method with very good long-term results. For patients in whom a suitable autologous venous graft is not available, the use of a venous allograft is an alternative procedure. A 68 years old man with ischaemic disease of lower extremities and gangrene of the left foot was admitted to our Centre in August 2014. He underwent percutaneous transluminal angioplasty of crural arteries of his left lower extremity. This, however, failed to improve peripheral circulation. The patient was then indicated for pedal or distal crural vascular reconstruction. Since no suitable autologous vein was available, distal bypass surgery using a donor graft remained the only option for limb salvage. Amputation of the toes on the left foot due to gangrene was necessary. Subsequently, femoro-pedal bypass to the left common plantar artery was performed using a great saphenous vein allograft. The post-operative course was without complications, the pedal bypass was patent and toe amputation was with good healing. The patient remained in follow-up care. A good outcome of vascular reconstruction with an allograft depends on the availability of a suitable allograft and good patient compliance with post-operative care. In the case presented here, the pedal bypass grafting by means of an allograft helped to save the patients limb. pedal bypass venous allograft limb salvage.
Performance improvement of long-range surface plasmon structure for use in an all-optical switch
NASA Astrophysics Data System (ADS)
Jandaghian, Ali; Lotfalian, Ali; Kouhkan, Mohsen; Mohajerani, Ezeddin
2017-12-01
This paper presents important parameters in performance of long-range surface plasmon (LRSP) structure (SF4/PVA/silver/PMMA-DR1) that are improved. We select poly(vinyl alcohol) (PVA) as the first dielectric layer due to its water solubility and good optical properties. The thickness of PVA and silver layers is optimized by transfer matrix method based on Fresnel equations. Surface morphologies of PVA and silver surfaces are analyzed by AFM imaging due to their important role in the performance of an LRSP structure. Furthermore, the sensitivity of an all-optical switch based on plasmon is investigated. In order to compare the sensitivity of LRSP and conventional surface plasmon (SP) structures in switching mode, full wide of half maximum, resonance angles, and pump powers of both structures are measured by a custom-made optical setup based on angular interrogation with a precision of 0.01 deg. Finally, we conclude that for creating equal signal levels in both samples, the required pump power for LRSP structure was about three times less than that for conventional SP; thus, these results led to power savings in optical switches.
Saifullah, Bullo; El Zowalaty, Mohamed E; Arulselvan, Palanisamy; Fakurazi, Sharida; Webster, Thomas J; Geilich, Benjamin M; Hussein, Mohd Zobir
2014-01-01
The treatment of tuberculosis by chemotherapy is complicated due to multiple drug prescriptions, long treatment duration, and adverse side effects. We report here for the first time an in vitro therapeutic effect of nanocomposites based on para-aminosalicylic acid with zinc layered hydroxide (PAS-ZLH) and zinc-aluminum layered double hydroxides (PAS-Zn/Al LDH), against mycobacteria, Gram-positive bacteria, and Gram-negative bacteria. The nanocomposites demonstrated good antimycobacterial activity and were found to be effective in killing Gram-positive and Gram-negative bacteria. A biocompatibility study revealed good biocompatibility of the PAS-ZLH nanocomposites against normal human MRC-5 lung cells. The para-aminosalicylic acid loading was quantified with high-performance liquid chromatography analysis. In summary, the present preliminary in vitro studies are highly encouraging for further in vivo studies of PAS-ZLH and PAS-Zn/Al LDH nanocomposites to treat tuberculosis. PMID:25114509
Kueseng, Pamornrat; Pawliszyn, Janusz
2013-11-22
A new thin-film, carboxylated multiwalled carbon nanotubes/polydimethylsiloxane (MWCNTs-COOH/PDMS) coating was developed for 96-blade solid-phase microextraction (SPME) system followed by high performance liquid chromatography with ultraviolet detection (HPLC-UV). The method provided good extraction efficiency (64-90%) for three spiked levels, with relative standard deviations (RSD)≤6%, and detection limits between 1 and 2 μg/L for three phenolic compounds. The MWCNTs-COOH/PDMS 96-blade SPME system presents advantages over traditional methods due to its simplicity of use, easy coating preparation, low cost and high sample throughput (2.1 min per sample). The developed coating is reusable for a minimum of 110 extractions with good extraction efficiency. The coating provided higher extraction efficiency (3-8 times greater) than pure PDMS coatings. Copyright © 2013 Elsevier B.V. All rights reserved.
1-Ethyl-1-methyl piperidinium bis(trifluoromethanesulfonyl)imide as a co-solvent in Li-ion batteries
NASA Astrophysics Data System (ADS)
Kim, Ketack; Cho, Young-Hyun; Shin, Heon-Cheol
2013-03-01
1-Ethyl-1-methyl piperidinium bis(trifluoromethanesulfonyl)imide (EMP-TFSI) is an ionic liquid with a melting temperature of 85 °C. Although it is a solid salt, it shows good miscibility with carbonate solvents, which allows EMP-TFSI to be used as a co-solvent in these systems. Ethylene carbonate is another solid co-solvent used in Li-ion batteries. Due to its smaller cationic size, EMP-TFSI provides better conductivity as a co-solvent than 1-methyl-1-propyl piperidinium bis(trifluoromethanesulfonyl)imide (MPP-TFSI), which is the smallest room-temperature piperidinium liquid salt known. In cells with 50 wt% IL and 50 wt% carbonate electrolyte, an EMP-TFSI mixed electrolyte performs better than an MPP-TFSI mixed electrolyte. Additionally, the discharge capacity values obtained from rate capability tests carried out with mixed EMP-TFSI are as good as those conducted with a pure carbonate electrolyte.
Shakirov, Babur M; Tagaev, Komil R; Tursunov, Bachron S; Achtamov, Dgamshed A
2009-03-01
The burn trauma of the posterior surface of calcaneus region and ankle joint followed by cicatrix formation in the Achilles tendon zone is often complicated by unhealing trophic ulcers. Eleven patients (seven men and four women, aged 9-54 years) have been operated on under our observation for prolonged unhealing ulcers and cicatrices located in the Achilles tendon zone. After cicatrices dissection, L-form plastic surgery was performed. The postoperative period was smooth; a skin graft was appropriately fixed to the proper tissues and the wound margins. Good results were achieved in 10 cases, and no complications were noted. However, in only one patient a marginal necrosis of the external talus part adjoining the ulcer due to tissue changes has been noted, but that had no influence on the good results of the operation.
Pigment dispersion syndrome associated with intraocular lens implantation: a new surgical technique.
Canut Jordana, M Isabel; Pérez Formigó, Daniel; Abreu González, Rodrigo; Nadal Reus, Jeroni
2010-11-11
We report the case of a myopic patient who, after intraocular lens transplant in the posterior chamber, suffered elevated intraocular pressure due to pigment dispersion, with recurrent episodes of blurred vision. The patient was treated with a new surgical technique that can avoid potential iridolenticular contact. Complete ophthalmologic examination and optical coherence tomography (OCT) of the anterior segment were performed. Contact between the pigmentary epithelium and the iris with an intraocular lens was revealed by utrasound biomicroscopy and OCT. In this case, Nd:YAG laser iridotomy and laser iridoplasty were not effective for iridolenticular separation and control of the pigment dispersion. We propose a new technique: stitches on the surface of the iris to obtain good iridolenticular separation and good intraocular pressure control. Stitches on the iris surface should be considered as optional therapy in pigmentary glaucoma secondary to intraocular lens implantation. This surgical technique can avoid potential iridolenticular contacts more definitively.
NASA Astrophysics Data System (ADS)
Cho, Young Jun; Jang, Hanmin; Lee, Kwan-Soo; Kim, Dong Rip
2015-06-01
Superhydrophobic surfaces with anti-corrosion properties have attracted great interest in many industrial fields, particularly to enhance the thermal performance of offshore applications such as heat exchangers, pipelines, power plants, and platform structures. Nanostructures with hydrophobic materials have been widely utilized to realize superhydrophobicity of surfaces, and cerium oxide has been highlighted due to its good corrosion resistive and intrinsically hydrophobic properties. However, few studies of direct growth of cerium oxide nanostructures on diverse substrates have been reported. Herein we report a facile hydrothermal method to directly grow cerium oxide nanorods on diverse substrates, such as aluminum alloy, stainless steel, titanium, and silicon. Diverse substrates with cerium oxide nanorods exhibited superhydrophobicity with no hydrophobic modifiers on their surfaces, and showed good corrosion resistive properties in corrosive medium. We believe our method could pave the way for realization of scalable and sustainable corrosion resistive superhydrophobic surfaces in many industrial fields.
Wang, Shuli; Yu, Nianzuo; Wang, Tieqiang; Ge, Peng; Ye, Shunsheng; Xue, Peihong; Liu, Wendong; Shen, Huaizhong; Zhang, Junhu; Yang, Bai
2016-05-25
This article shows morphology-patterned stripes as a new platform for directing flow guidance of the fluid in microfluidic devices. Anisotropic (even unidirectional) spreading behavior due to anisotropic wetting of the underlying surface is observed after integrating morphology-patterned stripes with a Y-shaped microchannel. The anisotropic wetting flow of the fluid is influenced by the applied pressure, dimensions of the patterns, including the period and depth of the structure, and size of the channels. Fluids with different surface tensions show different flowing anisotropy in our microdevice. Moreover, the morphology-patterned surfaces could be used as a microvalve, and gas-water separation in the microchannel was realized using the unidirectional flow of water. Therefore, benefiting from their good performance and simple fabrication process, morphology-patterned surfaces are good candidates to be applied in controlling the fluid behavior in microfluidics.
NASA Astrophysics Data System (ADS)
Jamil, N. H.; Ibrahim, W. M. A. W.; Abdullah, M. M. A. B.; Sandu, A. V.; Tahir, M. F. M.
2017-06-01
Porous ceramic nowadays has been investigated for a variety of its application such as filters, lightweight structural component and others due to their specific properties such as high surface area, stability and permeability. Besides, it has the properties of low thermal conductivity. Various formation techniques making these porous ceramic properties can be tailored or further fine-tuned to obtain the optimum characteristic. Porous materials also one of the good candidate for absorption properties. Conventional construction materials are not design to have good water absorption and retention that lead to the poor performance on these criteria. Temperature is a major driving force for moisture movement and influences sorption characteristics of many constructions materials. The effect of elevated temperatures on the water absorption coefficient and retention remain as critical issue that need to be investigated. Therefore, this paper will review the process parameters in fabricating porous ceramic for absorption properties.
Normally-off AlGaN/GaN-based MOS-HEMT with self-terminating TMAH wet recess etching
NASA Astrophysics Data System (ADS)
Son, Dong-Hyeok; Jo, Young-Woo; Won, Chul-Ho; Lee, Jun-Hyeok; Seo, Jae Hwa; Lee, Sang-Heung; Lim, Jong-Won; Kim, Ji Heon; Kang, In Man; Cristoloveanu, Sorin; Lee, Jung-Hee
2018-03-01
Normally-off AlGaN/GaN-based MOS-HEMT has been fabricated by utilizing damage-free self-terminating tetramethyl ammonium hydroxide (TMAH) recess etching. The device exhibited a threshold voltage of +2.0 V with good uniformity, extremely small hysteresis of ∼20 mV, and maximum drain current of 210 mA/mm. The device also exhibited excellent off-state performances, such as breakdown voltage of ∼800 V with off-state leakage current as low as ∼10-12 A and high on/off current ratio (Ion/Ioff) of 1010. These excellent device performances are believed to be due to the high quality recessed surface, provided by the simple self-terminating TMAH etching.
Protective Performance of Polyaniline-Sulfosalicylic Acid/Epoxy Coating for 5083 Aluminum
Liu, Suyun; Liu, Li; Meng, Fandi; Li, Ying; Wang, Fuhui
2018-01-01
Epoxy coatings incorporating different content of sulfosalicylic acid doped polyaniline (PANI-SSA) have been investigated for corrosion protection of 5083 aluminum alloy in 3.5% NaCl solution. The performance of the coatings is studied using a combination of electrochemical impedance spectroscopy (EIS), open circuit potential (OCP), gravimetric tests, adhesion tests, scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The results demonstrate that the content of PANI-SSA not only affects the coating compactness and the transportation of aggressive medium, but also has a significant influence on the-based aluminum. The coating with 2 wt. % PANI-SSA exhibits the best corrosion inhibition due to its good protective properties and the formation of a complete PANI-SSA induced oxide layer. PMID:29438304
28 CFR 523.10 - Purpose and scope.
Code of Federal Regulations, 2010 CFR
2010-07-01
... TRANSFER COMPUTATION OF SENTENCE Extra Good Time § 523.10 Purpose and scope. (a) The Bureau of Prisons awards extra good time credit for performing exceptionally meritorious service, or for performing duties... of extra good time award at a time (e.g., an inmate earning industrial or camp good time is not...
28 CFR 523.10 - Purpose and scope.
Code of Federal Regulations, 2014 CFR
2014-07-01
... TRANSFER COMPUTATION OF SENTENCE Extra Good Time § 523.10 Purpose and scope. (a) The Bureau of Prisons awards extra good time credit for performing exceptionally meritorious service, or for performing duties... of extra good time award at a time (e.g., an inmate earning industrial or camp good time is not...
28 CFR 523.10 - Purpose and scope.
Code of Federal Regulations, 2011 CFR
2011-07-01
... TRANSFER COMPUTATION OF SENTENCE Extra Good Time § 523.10 Purpose and scope. (a) The Bureau of Prisons awards extra good time credit for performing exceptionally meritorious service, or for performing duties... of extra good time award at a time (e.g., an inmate earning industrial or camp good time is not...
28 CFR 523.10 - Purpose and scope.
Code of Federal Regulations, 2013 CFR
2013-07-01
... TRANSFER COMPUTATION OF SENTENCE Extra Good Time § 523.10 Purpose and scope. (a) The Bureau of Prisons awards extra good time credit for performing exceptionally meritorious service, or for performing duties... of extra good time award at a time (e.g., an inmate earning industrial or camp good time is not...
28 CFR 523.10 - Purpose and scope.
Code of Federal Regulations, 2012 CFR
2012-07-01
... TRANSFER COMPUTATION OF SENTENCE Extra Good Time § 523.10 Purpose and scope. (a) The Bureau of Prisons awards extra good time credit for performing exceptionally meritorious service, or for performing duties... of extra good time award at a time (e.g., an inmate earning industrial or camp good time is not...
Harmonisation and diagnostics of MIPAS ESA CH4 and N2O profiles using data assimilation
NASA Astrophysics Data System (ADS)
Errera, Quentin; Ceccherini, Simone; Christophe, Yves; Chabrillat, Simon; Hegglin, Michaela I.; Lambert, Alyn; Ménard, Richard; Raspollini, Piera; Skachko, Sergey; van Weele, Michiel; Walker, Kaley A.
2016-12-01
This paper discusses assimilation experiments of methane (CH4) and nitrous oxide (N2O) profiles retrieved from the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS). Here we focus on data versions 6 and 7 provided by the ESA processor. These data sets have been assimilated by the Belgian Assimilation System for Chemical ObsErvations (BASCOE). The CH4 and N2O retrieved profiles can oscillate, especially in the tropical lower stratosphere. Using the averaging kernels of the observations and a background error covariance matrix, which has previously been calibrated, allows the system to partly remedy this issue and provide assimilated fields that are more regular vertically. In general, there is a good agreement between the BASCOE analyses and independent observations from ACE-FTS (CH4 and N2O) and MLS (N2O), demonstrating the general good quality of CH4 and N2O retrievals provided by MIPAS ESA. Nevertheless, this study also identifies two issues in these data sets. First, time series of the observations show unexpected discontinuities due to an abrupt change in the gain of MIPAS band B, generally occurring after the instrument decontamination. Since the calibration is performed weekly, the abrupt change in the gain affects the measurements until the subsequent calibration is performed. Second, the correlations between BASCOE analyses and independent observations are poor in the lower stratosphere, especially in the tropics, probably due to the presence of outliers in the assimilated data. In this region, we recommend using MIPAS CH4 and N2O retrievals with caution.
Quantitative evaluation of patient-specific quality assurance using online dosimetry system
NASA Astrophysics Data System (ADS)
Jung, Jae-Yong; Shin, Young-Ju; Sohn, Seung-Chang; Min, Jung-Whan; Kim, Yon-Lae; Kim, Dong-Su; Choe, Bo-Young; Suh, Tae-Suk
2018-01-01
In this study, we investigated the clinical performance of an online dosimetry system (Mobius FX system, MFX) by 1) dosimetric plan verification using gamma passing rates and dose volume metrics and 2) error-detection capability evaluation by deliberately introduced machine error. Eighteen volumetric modulated arc therapy (VMAT) plans were studied. To evaluate the clinical performance of the MFX, we used gamma analysis and dose volume histogram (DVH) analysis. In addition, to evaluate the error-detection capability, we used gamma analysis and DVH analysis utilizing three types of deliberately introduced errors (Type 1: gantry angle-independent multi-leaf collimator (MLC) error, Type 2: gantry angle-dependent MLC error, and Type 3: gantry angle error). A dosimetric verification comparison of physical dosimetry system (Delt4PT) and online dosimetry system (MFX), gamma passing rates of the two dosimetry systems showed very good agreement with treatment planning system (TPS) calculation. For the average dose difference between the TPS calculation and the MFX measurement, most of the dose metrics showed good agreement within a tolerance of 3%. For the error-detection comparison of Delta4PT and MFX, the gamma passing rates of the two dosimetry systems did not meet the 90% acceptance criterion with the magnitude of error exceeding 2 mm and 1.5 ◦, respectively, for error plans of Types 1, 2, and 3. For delivery with all error types, the average dose difference of PTV due to error magnitude showed good agreement between calculated TPS and measured MFX within 1%. Overall, the results of the online dosimetry system showed very good agreement with those of the physical dosimetry system. Our results suggest that a log file-based online dosimetry system is a very suitable verification tool for accurate and efficient clinical routines for patient-specific quality assurance (QA).
Spein, Anna Rita; Pedersen, Cecilia Petrine; Silviken, Anne Cathrine; Melhus, Marita; Kvernmo, Siv Eli; Bjerregaard, Peter
2013-01-01
Self-rated health (SRH) and associated risk and protective correlates were investigated among two indigenous adolescent populations, Greenlandic Inuit and Norwegian Sami. Cross-sectional data were collected from "Well-being among Youth in Greenland" (WBYG) and "The Norwegian Arctic Adolescent Health Study" (NAAHS), conducted during 2003-2005 and comprising 10th and 11th graders, 378 Inuit and 350 Sami. SRH was assessed by one single item, using a 4-point and 5-point scale for NAAHS and WBYG, respectively. Logistic regressions were performed separately for each indigenous group using a dichotomous measure with "very good" (NAAHS) and "very good/good" (WBYG) as reference categories. We simultaneously controlled for various socio-demographics, risk correlates (drinking, smoking, violence and suicidal behaviour) and protective correlates (physical activity, well-being in school, number of close friends and adolescent-parent relationship). A majority of both Inuit (62%) and Sami (89%) youth reported "good" or "very good" SRH. The proportion of "poor/fair/not so good" SRH was three times higher among Inuit than Sami (38% vs. 11%, p≤0.001). Significantly more Inuit females than males reported "poor/fair" SRH (44% vs. 29%, p≤0.05), while no gender differences occurred among Sami (12% vs. 9%, p≤0.08). In both indigenous groups, suicidal thoughts (risk) and physical activity (protective) were associated with poor and good SRH, respectively. In accordance with other studies of indigenous adolescents, suicidal thoughts were strongly associated with poorer SRH among Sami and Inuit. The Inuit-Sami differences in SRH could partly be due to higher "risk" and lower "protective" correlates among Inuit than Sami. The positive impact of physical activity on SRH needs to be targeted in future intervention programs.
Student perceptions of a good teacher: the gender perspective.
Jules, V; Kutnick, P
1997-12-01
A large-scale survey of pupils' perceptions of a good teacher in the Caribbean republic of Trinidad and Tobago is reported. An essay-based, interpretative mode of research was used to elicit and identify constructs used by boys and girls. The study explores similarities and differences between boys and girls in their perceptions of a good teacher, in a society where girls achieve superior academic performance (than boys). A total of 1756 pupils and students aged between 8 and 16 provided the sample, which was proportional, stratified, clustered. Within these constraints classrooms were randomly selected to be representative of primary and secondary schools across the two islands. Altogether 1539 essays and 217 interviews were content analysed, coded for age development and compared between boys and girls. Content items identified by the pupils were logically grouped into: physical and personal characteristics of the teacher, quality of the relationship between the teacher and pupil, control of behaviour by the teacher, descriptions of the teaching process, and educational and other outcomes obtained by pupils due to teacher efforts. Female pupils identified more good teacher concepts at all age levels than males. There was some commonality between the sexes in concepts regarding interpersonal relationships and inclusiveness in the good teachers' teaching practices and boys showed significantly greater concerns regarding teacher control and use of punishment. Males as young as 8 years stated that good teachers should be sensitive to their needs. Only among the 16-year-old males were males noted as good teachers. Consideration is given to the roles of male and female teachers, how their classroom actions may set the basis for future success (or failure) of their pupils, and the needs of pupils with regard to teacher support within developing and developed countries.
Meng, X H; Zeng, S X; Shi, Jonathan J; Qi, G Y; Zhang, Z B
2014-12-01
Based on a content analysis of 533 Chinese listed companies, this study examines how corporate environmental performance affects not only the level of detail of a company's environmental disclosures, but also what information is disclosed. The results show that (1) both poor and good performers have more disclosure than the median (i.e., "mixed") performers, which provides empirical evidence to support a nonlinear relationship between corporate environmental performance and environmental disclosure; (2) poor performers disclose more soft information on environmental performance than good performers, and good performers disclose more solid information; and (3) although poor performers increase disclosure after being exposed as environmental violators, they avoid disclosing negative environmental information, such as the violation and the associated penalties. This study provides additional evidence for a nonlinear relationship between environmental performance and disclosure in emerging markets, and suggests environmental disclosure may not be a valid signal to differentiate good performers from poor performers in contemporary China. Copyright © 2014 Elsevier Ltd. All rights reserved.
Gao, Yanyan; Xu, Jianping; Shi, Shaobo; Dong, Hong; Cheng, Yahui; Wei, Chengtai; Zhang, Xiaosong; Yin, Shougen; Li, Lan
2018-04-04
The self-powered ultraviolet photodetectors (UV PDs) have attracted increasing attention due to their potential applications without consuming any external power. It is important to obtain the high-performance self-powered UV PDs by a simple method for the practical application. Herein, TiO 2 nanorod arrays (NRs) were synthesized by hydrothermal method, which were integrated with p-type NiO nanoflakes to realize a high performance pn heterojunction for the efficient UV photodetection. TiO x thin film can improve the morphological and carrier transport properties of TiO 2 NRs and decrease the surface and defect states, resulting in the enhanced photocurrent of the devices. NiO/TiO 2 nanostructural heterojunctions show excellent rectifying characteristics (rectification ratio of 2.52 × 10 4 and 1.45 × 10 5 for NiO/TiO 2 NRs and NiO/TiO 2 NRs/TiO x , respectively) with a very low reverse saturation current. The PDs based on the heterojunctions exhibit good spectral selectivity, high photoresponsivity, and fast response and recovery speeds without external applied bias under the weak light radiation. The devices demonstrate good stability and repeatability under UV light radiation. The self-powered performance could be attributed to the proper built-in electric field of the heterojunction. TiO 2 NRs and NiO nanoflakes construct the well-aligned energy-band structure. The enhanced responsivity and detectivity for the devices with TiO x thin films is related to the increased interfacial charge separation efficiency, reduced carrier recombination, and relatively good electron transport of TiO 2 NRs.
Pozzi, Matteo; Koffel, Catherine; Djaref, Camelia; Grinberg, Daniel; Fellahi, Jean Luc; Hugon-Vallet, Elisabeth; Prieur, Cyril; Robin, Jacques; Obadia, Jean François
2017-07-01
Cardiac failure is still a leading cause of death in drug intoxication. Extracorporeal life support (ECLS) could be used as a rescue therapeutic option in patients developing refractory cardiogenic shock or cardiac arrest. The aim of this report is to present our results of ECLS in the setting of poisoning from cardiotoxic drugs. We included in this analysis consecutive patients who received an ECLS for refractory cardiogenic shock or in-hospital cardiac arrest due to drug intoxication. The primary endpoint of our study was survival to hospital discharge with good neurological recovery after ECLS support. Between January 2010 and December 2015, we performed 12 ECLS. Mean age was 44.2±17.8 years and there was a predominance of females (66.7%). Drug intoxication was mainly due to beta-blockers and/or calcium channel inhibitors (83.3%) and 5 (41.7%) patients had multiple drugs overdose. Weaning rate and survival to hospital discharge with good neurological recovery were 75% (9 patients). Among patients weaned from ECLS, mean duration of support was 2.4±1.1 days. Three (25%) patients underwent ECLS implantation during cardiopulmonary resuscitation, 2 (66.6%) of them died while on mechanical circulatory support (MCS). Six (50%) patients developed lower limb ischemia. Each patient was managed with ECLS decannulation: 2 (16.7%) patients underwent a concomitant iliofemoral thrombectomy, 3 (25%) needed further fasciotomy and the remaining patient (8.3%) required an amputation. Refractory cardiogenic shock due to drug intoxication is still one of the best indications for ECLS owing to the satisfactory survival with good neurological outcome in such a critically ill population. Further data are however necessary in order to best understand the possible relation between drug intoxication and lower limb ischemia, which was quite superior to the reported rates.
Habitat Evaluation Procedures (HEP) Report : Oxbow Conservation Area, 2002-2005 Technical Report.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Cochran, Brian
2005-02-01
This Habitat Evaluation Procedure (HEP) study was performed to determine baseline habitat units on the Oxbow Conservation Area in Grant County, Oregon. The evaluation is a required part of the Memorandum of Agreement between the Confederated Tribes of the Warm Springs and Bonneville Power Administration (BPA) relating to the acquisition and management of the Oxbow Conservation Area. The HEP team was comprised of individuals from the Washington Department of Fish and Wildlife and the Confederated Tribes of the Warm Springs Reservation of Oregon. The survey was conducted using the following HEP evaluation models for key species: black-capped chickadee (Poecile atricapilla),more » mallard (Anas platyrhynchos), mink (Mustela vison), western meadowlark (Sturnella neglecta), white-tailed deer (Odocoileus virginiana), and yellow warbler (Dendroica petechia). Cover types used in this survey were conifer forest, irrigated meadow, riparian meadow, upland meadow, riparian shrub, upland shrub, and mine tailings. The project generated 701.3 habitat units for mitigation crediting purposes. Results for each HEP species are: (1) Black-capped chickadee habitat was good, with only isolated areas lacking snags or having low tree canopy cover. (2) Mallard habitat was poor in upland meadows and marginal elsewhere due to a lack of herbaceous/shrub cover and low herbaceous height. (3) Mink habitat was good, limited only by the lack of the shrub component. (4) Western meadowlark habitat was marginal in upland meadow and mine tailing cover types and good in irrigated meadow. Percent cover of grass and height of herbaceous variables were limiting factors. (5) White-tailed deer habitat was marginal due to relatively low tree canopy cover, reduced shrub cover, and limited browse diversity. (6) Yellow Warbler habitat was marginal due to less than optimum shrub height and the lack of hydrophytic shrubs. General ratings (poor, marginal, etc.) are described in the introduction section.« less
Giers, Bert C; Khoramnia, Ramin; Weber, Lea F; Tandogan, Tamer; Auffarth, Gerd U
2016-03-01
We present the case of a 56-year-old woman with moderate myopia and bilateral cataract who had cataract extraction and intraocular lens (IOL) implantation. Due to the patient's desire for spectacle independence, a trifocal IOL with toric correction for astigmatism was implanted. During the follow-up, it became obvious that the implanted IOL had rotated and tilted due to insufficient fixation in the large capsular bag of the myopic eye. An IOL explantation was therefore performed, and the original IOL was exchanged for a bifocal toric IOL with a larger overall diameter. Stable fixation of the IOL in the capsular bag was achieved, and after surgery in the second eye, the patient recovered good bilateral vision. This case illustrates the need for careful selection of IOL diameter and sizing even in patients with moderate myopia due to the potentially larger ocular dimensions in these patients. Copyright © 2016 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Fu, Shaofang; Zhu, Chengzhou; Su, Dong
As one of the alternatives to replace precious metal catalysts, transition metal-nitrogen-carbon (M-N-C) electrocatalysts have attracted great research interest due to their low cost and good catalytic activities. Despite nanostructured M-N-C catalysts can achieve good electrochemical performances, they are vulnerable to aggregation and insufficient catalytic sites upon continuous catalytic reaction. Thus, M-N-C’s stability and selectivity have not been comparable to their noble metal counterparts. In this work, metal-organic frameworks (MOFs)-derived porous single-atom electrocatalysts (SAEs) were successfully prepared by simple pyrolysis procedure without any further post-treatment. Combining the X-ray absorption near-edge spectroscopy (XANES) and electrochemical measurements, the SAEs have been identifiedmore » with superior ORR activity and stability compared with Pt/C catalysts in alkaline condition. More impressively, the SAEs also show excellent ORR electrocatalytic performance in both acid and neutral media. Furthermore, this study of nonprecious catalysts provides new insights on nano-engineering catalytically active sites and porous structures for nonprecious metal ORR catalysis in a wide range of pH.« less
Fu, Shaofang; Zhu, Chengzhou; Su, Dong; ...
2018-02-12
As one of the alternatives to replace precious metal catalysts, transition metal-nitrogen-carbon (M-N-C) electrocatalysts have attracted great research interest due to their low cost and good catalytic activities. Despite nanostructured M-N-C catalysts can achieve good electrochemical performances, they are vulnerable to aggregation and insufficient catalytic sites upon continuous catalytic reaction. Thus, M-N-C’s stability and selectivity have not been comparable to their noble metal counterparts. In this work, metal-organic frameworks (MOFs)-derived porous single-atom electrocatalysts (SAEs) were successfully prepared by simple pyrolysis procedure without any further post-treatment. Combining the X-ray absorption near-edge spectroscopy (XANES) and electrochemical measurements, the SAEs have been identifiedmore » with superior ORR activity and stability compared with Pt/C catalysts in alkaline condition. More impressively, the SAEs also show excellent ORR electrocatalytic performance in both acid and neutral media. Furthermore, this study of nonprecious catalysts provides new insights on nano-engineering catalytically active sites and porous structures for nonprecious metal ORR catalysis in a wide range of pH.« less
Pandey, Preeti; Pandey, S.; Dubey, Shaifali
2013-01-01
Etodolac, a nonsteroidal antiinflammatory drug, widely used in arthritis is associated with gastric ulceration and irritation due to presence of free carboxylic group. The current investigation reports synthesis of mutual amide prodrug of etodolac by masking free carboxylic group with glucosamine, a nutritional supplement for treatment of arthritis. Confirmation and characterization of the structure of the synthesized prodrug done by elemental and spectroscopy analysis, melting point, determination of migration parameters (Rf, RM, and Rt) by using thin layer chromatography and high performance liquid chromatography, respectively. Partition coefficient and solubility study confirms its lipophilic character so can be suitable candidate for controlled release delivery. In vitro hydrolytic studies of prodrug confirms good rate of hydrolysis in blood plasma, fecal matter, and simulated intestinal fluid while stable in gastric simulated fluid. In vivo pharmacological screening performed on animals. Prodrug with respect to etodolac shows good analgesic, antiinflammatory, and antiarthritic activity. The prodrug was assessed for their probable damaging effects by ulcerogeniticity and histopathological analysis. The histopathological studies showed less ulceration in the gastric region when treated with prodrug, thereby proving the prodrug to be better in action as compared to etodolac and are advantageous in having less gastrointestinal side effects. PMID:24302794
Mohan, S Venkata; Chandrasekhar, K
2011-07-01
Solid phase microbial fuel cells (SMFC; graphite electrodes; open-air cathode) were designed to evaluate the potential of bioelectricity production by stabilizing composite canteen based food waste. The performance was evaluated with three variable electrode-membrane assemblies. Experimental data depicted feasibility of bioelectricity generation from solid state fermentation of food waste. Distance between the electrodes and presence of proton exchange membrane (PEM) showed significant influence on the power yields. SMFC-B (anode placed 5 cm from cathode-PEM) depicted good power output (463 mV; 170.81 mW/m(2)) followed by SMFC-C (anode placed 5 cm from cathode; without PEM; 398 mV; 53.41 mW/m(2)). SMFC-A (PEM sandwiched between electrodes) recorded lowest performance (258 mV; 41.8 mW/m(2)). Sodium carbonate amendment documented marked improvement in power yields due to improvement in the system buffering capacity. SMFCs operation also documented good substrate degradation (COD, 76%) along with bio-ethanol production. The operation of SMFC mimicked solid-sate fermentation which might lead to sustainable solid waste management practices. Copyright © 2011 Elsevier Ltd. All rights reserved.
Measurement of discharge using tracers
Kilpatrick, Frederick A.; Cobb, Ernest D.
1984-01-01
The development of fluorescent dyes and fluorometers that can measure these dyes at very low concentrations has made dye-dilution methods practical for measuring discharge. These methods are particularly useful for determining discharge under certain flow conditions that are unfavorable for current meter measurements. These include small streams, canals, and pipes where:Turbulence is excessive for current meter measurement but conducive to good mixing.Moving rocks and debris are damaging to any instruments placed in the flow.Cross-sectional areas or velocities are indeterminant or changing.There are some unsteady flows such as exist with storm-runoff events on small streams.The flow is physically inaccessible or unsafe.From a practical standpoint, such measurements are limited primarily to small streams due to excessively long channel mixing lengths required of larger streams. Very good accuracy can be obtained provided:Adequate mixing length and time are allowed.Careful field and laboratory techniques are employed.Dye losses are not significant.This manual describes the slug-injection and constant-rate injection methods of performing tracer-dilution measurements. Emphasis is on the use of fluorescent dyes as tracers and the equipment, field methods, and Laboratory procedures for performing such measurements. The tracer-velocity method is also briefly discussed.
[Bacillus cereus endocarditis and a probable cutaneous gateway].
Soudet, S; Becquart, C; Dezoteux, F; Faure, K; Staumont-Salle, D; Delaporte, E
2017-01-01
Bacillus cereus is a ubiquitous telluric organism. B. cereus endocarditis is a rare condition seen mostly in prosthetic heart valves and among intravenous drug users. We report a new case of a patient without risk factors and with a good clinical outcome not requiring valve replacement. In October 2014, a 50-year-old woman was referred to the dermatology department of Lille University Hospital for lower-limb wounds developing 6 months earlier. She presented fever without clinical signs of infection, except for the lower-limbs wounds. Blood cultures revealed the presence of B. cereus. Transesophageal echocardiography was performed and revealed two foci of aortic valve vegetation with a diameter of 5mm. After bacterial sensitivity testing, rifampicin and levofloxacin treatment was given for six weeks, with complete remission. A skin graft was performed and good improvement was seen. Nineteen cases of B. cereus endocarditis have been described previously, only one of which was without risk factors. We described a case of complete remission after a 6-week course of antibiotics. Our case demonstrates that BC should not be considered as a blood culture contamination, and that treatment may be complex due to antibiotic resistance. Copyright © 2016 Elsevier Masson SAS. All rights reserved.
Psychometric properties of the Nurses Work Functioning Questionnaire (NWFQ).
Gärtner, Fania R; Nieuwenhuijsen, Karen; van Dijk, Frank J H; Sluiter, Judith K
2011-01-01
The Nurses Work Functioning Questionnaire (NWFQ) is a 50-item self-report questionnaire specifically developed for nurses and allied health professionals. Its seven subscales measure impairments in the work functioning due to common mental disorders. Aim of this study is to evaluate the psychometric properties of the NWFQ, by assessing reproducibility and construct validity. The questionnaire was administered to 314 nurses and allied health professionals with a re-test in 112 subjects. Reproducibility was assessed by the intraclass correlations coefficients (ICC) and the standard error of measurement (SEM). For construct validity, correlations were calculated with a general work functioning scale, the Endicott Work Productivity Scale (EWPS) (convergent validity) and with a physical functioning scale (divergent validity). For discriminative validity, a Mann Whitney U test was performed testing for significant differences between subjects with mental health complaints and without. All subscales showed good reliability (ICC: 0.72-0.86), except for one (ICC = 0.16). Convergent validity was good in six subscales, correlations ranged from 0.38-0.62. However, in one subscale the correlation with the EWPS was too low (0.22). Divergent validity was good in all subscales based on correlations ranged from (-0.06)-(-0.23). Discriminative validity was good in all subscales, based on significant differences between subjects with and without mental health complaints (p<0.001-p = 0.003). The NWFQ demonstrates good psychometric properties, for six of the seven subscales. Subscale "impaired decision making" needs improvement before further use.
Kujawa-Roeleveld, K; Elmitwalli, T; Gaillard, A; van Leeuwen, M; Zeeman, G
2003-01-01
Co-digestion of concentrated black water and kitchen refuse within the DESAR concept was the objective of this pilot research. The digestion took place in two, non-mixed accumulation reactors (AC1 and AC2) inoculated with digested primary sludge from a WWTP at a temperature of 20 degrees C for a period of around 150 days. Reactor AC1 was fed with a mixture of faeces, urine and kitchen refuse in the equivalent amount that one individual generates per day. The AC2 was fed with a mixture of faeces and kitchen refuse in the equivalent amount that two individuals produce per day. Some contribution of urine to AC2 was not to be avoided. Detailed characterisation of waste(water) was performed. The performance of the stratified reactor was followed by monitoring the reactor content for several reactors' heights as well as being based on the biogas production. In general the system exposed good process stability. The methanisation of 34 and 61% was obtained for AC1 and AC2 respectively. The biogas yield was 26.5 and 50.8 L/p/d for the respective reactors. Proper choice of inoculum as well as good buffering capacity did not lead to accumulation of VFA and an inhibitive effect due to relatively high ammonium concentration. The chosen process is a promising technology showing good process stability especially for high strength influent.
Giannoni, S; Benassai, C; Allori, O; Valeri, E; Ferri, L; Dragotto, A
2004-09-01
Tracheomalacia is a process characterized by softness of the supporting tracheal cartilages, by the extension of the posterior membranous wall and by reduction of the tracheal antero-posterior diameter. Exceptionally, tracheomalacia can be associated with tracheobronchomegaly or Mounier-Kuhn syndrome. Fibro-bronchoscopy represents the ''gold standard'' for diagnosis. The case of a 79-year-old male observed after hospitalization in a medical ward for chronic pulmonary obstructive disease (COPD) decompensation, and with basal left bronchopulmonary focus, is described. During this period, a progressive worsening of clinical conditions occurred, despite cortisone and antibiotic therapy, and the patient was transferred to the ICU for dyspnea, hypoxia, hypocapnia and with a diagnosis of pulmonary fibrosis. Bronchoscopy, performed during spontaneous breathing, revealed tracheomalacia which was responsible for tracheal dynamic complete stenosis during expiration and dynamic subtotal stenosis of the left primary bronchus in the first tract, together with sputum retention. Moreover, this investigation confirmed the diagnosis of tracheobronchomegaly already seen on CT. It was suggested to place a Freitag stent, since the insertion of another model would not have had enough chance of stability, due to the enormous extension of the tracheal lumen and could not have guaranteed good clearance of the secretions. Seven days after this intervention, performed in an outpatients' setting, the patient was dismissed from the ICU, without the help of O2, with good ventilation, saturation in line with his age and good expectoration.
Bramesfeld, A; Stegbauer, C
2016-10-01
The World Health Organisation has defined health service responsiveness as one of the key-objectives of health systems. Health service responsiveness relates to the ability to respond to service users' legitimate expectations on non-medical issues when coming into contact with the services of a healthcare system. It is defined by the areas showing respect for persons and patient orientation. Health service responsiveness is particularly relevant to mental health services, due to the specific vulnerability of mental health patients but also because it matches what mental health patients consider as good quality of care as well as their priorities when seeking healthcare. As (mental) health service responsiveness applies equally to all concerned services it would be suitable as a universal indicator for the quality of services' performance. However, performance monitoring programs in mental healthcare rarely assess health service performance with respect to meeting patient priorities. This is in part due of patient priorities as an outcome being underrepresented in studies that evaluate service provision. The lack of studies using patient priorities as outcomes transmits into evidence based guidelines and subsequently, into underrepresentation of patient priorities in performance monitoring. Possible ways out of this situation include more intervention studies using patient priorities as outcome, considering evidence from qualitative studies in guideline development and developing performance monitoring programs along the patient pathway and on key-points of relevance for service quality from a patient perspective.
NASA Astrophysics Data System (ADS)
Ferhati, H.; Djeffal, F.
2017-12-01
In this paper, a new junctionless optical controlled field effect transistor (JL-OCFET) and its comprehensive theoretical model is proposed to achieve high optical performance and low cost fabrication process. Exhaustive study of the device characteristics and comparison between the proposed junctionless design and the conventional inversion mode structure (IM-OCFET) for similar dimensions are performed. Our investigation reveals that the proposed design exhibits an outstanding capability to be an alternative to the IM-OCFET due to the high performance and the weak signal detection benefit offered by this design. Moreover, the developed analytical expressions are exploited to formulate the objective functions to optimize the device performance using Genetic Algorithms (GAs) approach. The optimized JL-OCFET not only demonstrates good performance in terms of derived drain current and responsivity, but also exhibits superior signal to noise ratio, low power consumption, high-sensitivity, high ION/IOFF ratio and high-detectivity as compared to the conventional IM-OCFET counterpart. These characteristics make the optimized JL-OCFET potentially suitable for developing low cost and ultrasensitive photodetectors for high-performance and low cost inter-chips data communication applications.
NASA Astrophysics Data System (ADS)
Fouache, S.; Douady, J. P.; Fossati, G.; Pascon, C.
Valve-regulated lead/acid (VRLA) batteries have been available since the beginning of the 1970s for stationary applications. Nevertheless, the development and the commercialization of VRLA starter batteries have been very slow and mainlyrestricted to certain niche markets. This is due to the difficulty in designing products that comply with the technical specificationsrequired by the operating conditions of modern cars, and that have both a high level of reliability and a cost in accordance with the needs ofthe automotive market. The STR (sealed technology with gas recombination) battery has been developed in order to place on the automotiveoriginal equipment and replacement markets a battery with the benefits of the VRLA technology, namely: absolutely no maintenance; cleanand safe; good open-circuit storage; good cycling ability; performance comparable with that of flooded batteries (i.e., cranking powerand reserve capacity, charge acceptance, rechargeability, and life). Due to the technical choices made for the components and forthe manufacturing process, the STR battery is today manufactured on a production line very similar to that for a flooded battery, with agood level of productivity and the same reliability as the best flooded batteries. For all these reasons, the STR battery is producedat a cost that is acceptable for automotive applications.
NASA Astrophysics Data System (ADS)
Pang, Huan; Zhang, Yizhou; Cheng, Tao; Lai, Wen-Yong; Huang, Wei
2015-09-01
Uniform manganese hexacyanoferrate hydrate nanocubes are prepared via a simple chemical precipitation method at room temperature. Due to both micro/mesopores of the Prussian blue analogue and nanocubic structures, the manganese hexacyanoferrate hydrate nanocubes allow the efficient charge transfer and mass transport for electrolyte solution and chemical species. Thus, the manganese hexacyanoferrate hydrate nanocube electrode shows a good rate capability and cycling stability for electrochemical capacitors. Furthermore, electrodes modified with manganese hexacyanoferrate hydrate nanocubes demonstrate a sensitive electrochemical response to hydrogen peroxide (H2O2) in buffer solutions with a high selectivity.Uniform manganese hexacyanoferrate hydrate nanocubes are prepared via a simple chemical precipitation method at room temperature. Due to both micro/mesopores of the Prussian blue analogue and nanocubic structures, the manganese hexacyanoferrate hydrate nanocubes allow the efficient charge transfer and mass transport for electrolyte solution and chemical species. Thus, the manganese hexacyanoferrate hydrate nanocube electrode shows a good rate capability and cycling stability for electrochemical capacitors. Furthermore, electrodes modified with manganese hexacyanoferrate hydrate nanocubes demonstrate a sensitive electrochemical response to hydrogen peroxide (H2O2) in buffer solutions with a high selectivity. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr04322k
Determination of polarimetric parameters of honey by near-infrared transflectance spectroscopy.
García-Alvarez, M; Ceresuela, S; Huidobro, J F; Hermida, M; Rodríguez-Otero, J L
2002-01-30
NIR transflectance spectroscopy was used to determine polarimetric parameters (direct polarization, polarization after inversion, specific rotation in dry matter, and polarization due to nonmonosaccharides) and sucrose in honey. In total, 156 honey samples were collected during 1992 (45 samples), 1995 (56 samples), and 1996 (55 samples). Samples were analyzed by NIR spectroscopy and polarimetric methods. Calibration (118 samples) and validation (38 samples) sets were made up; honeys from the three years were included in both sets. Calibrations were performed by modified partial least-squares regression and scatter correction by standard normal variation and detrend methods. For direct polarization, polarization after inversion, specific rotation in dry matter, and polarization due to nonmonosaccharides, good statistics (bias, SEV, and R(2)) were obtained for the validation set, and no statistically (p = 0.05) significant differences were found between instrumental and polarimetric methods for these parameters. Statistical data for sucrose were not as good as those of the other parameters. Therefore, NIR spectroscopy is not an effective method for quantitative analysis of sucrose in these honey samples. However, NIR spectroscopy may be an acceptable method for semiquantitative evaluation of sucrose for honeys, such as those in our study, containing up to 3% of sucrose. Further work is necessary to validate the uncertainty at higher levels.
Low-pass interference filters for submillimeter astronomy
NASA Technical Reports Server (NTRS)
Whitcomb, S. E.; Keene, J.
1980-01-01
Low-pass (long-wave transmitting) interference filters, suitable for broadband photometric observations, previously have been constructed from series of capacitive grids stretched on thin Mylar. These filters have the desired optical properties of high transmission, sharp cut-ons, and good blocking at short wavelengths. Their designs, however, do not scale from one wavelength to another and their performance can deteriorate at low temperatures due to differential contraction of the dielectric backing and the supporting structure. The deviation of these early filters from the predicted scaling was due primarily to the difference in refractive index between the backing material and the medium between the grids. In the present paper, filters are described in which dielectric spacers are used, instead of air, as the medium between the grids. This technique has improved the scaling and has reduced the distortion from differential contraction.
A hybrid LBG/lattice vector quantizer for high quality image coding
NASA Technical Reports Server (NTRS)
Ramamoorthy, V.; Sayood, K.; Arikan, E. (Editor)
1991-01-01
It is well known that a vector quantizer is an efficient coder offering a good trade-off between quantization distortion and bit rate. The performance of a vector quantizer asymptotically approaches the optimum bound with increasing dimensionality. A vector quantized image suffers from the following types of degradations: (1) edge regions in the coded image contain staircase effects, (2) quasi-constant or slowly varying regions suffer from contouring effects, and (3) textured regions lose details and suffer from granular noise. All three of these degradations are due to the finite size of the code book, the distortion measures used in the design, and due to the finite training procedure involved in the construction of the code book. In this paper, we present an adaptive technique which attempts to ameliorate the edge distortion and contouring effects.
Li, Zhixun; Zhang, Yingtao; Gong, Huiling; Li, Weimin; Tang, Xianglong
2016-12-01
Coronary artery disease has become the most dangerous diseases to human life. And coronary artery segmentation is the basis of computer aided diagnosis and analysis. Existing segmentation methods are difficult to handle the complex vascular texture due to the projective nature in conventional coronary angiography. Due to large amount of data and complex vascular shapes, any manual annotation has become increasingly unrealistic. A fully automatic segmentation method is necessary in clinic practice. In this work, we study a method based on reliable boundaries via multi-domains remapping and robust discrepancy correction via distance balance and quantile regression for automatic coronary artery segmentation of angiography images. The proposed method can not only segment overlapping vascular structures robustly, but also achieve good performance in low contrast regions. The effectiveness of our approach is demonstrated on a variety of coronary blood vessels compared with the existing methods. The overall segmentation performances si, fnvf, fvpf and tpvf were 95.135%, 3.733%, 6.113%, 96.268%, respectively. Copyright © 2016 Elsevier Ltd. All rights reserved.
Development and performance of self-sealed MRPC
NASA Astrophysics Data System (ADS)
Lyu, P.; Wang, Y.; Guo, B.; Han, D.; Li, Y.; Herrmann, N.; Deppner, I.; Simon, C.; Weidenkaff, P.; Jochen, F.; Loizeau, P.-A.; Laden Kis, M.
2017-03-01
The MRPC has been widely applied in the high-energy physics experiments in recent decades for its excellent timing performance and good efficiency. The Compressed Baryonic Matter (CBM) experiment at FAIR plans to build its TOF system based on the MRPCs, aiming at a good hadron identification. The CBM-TOF will work at a very high particle flux rate (~ 30 kHz/cm2) condition, and the long-time exposure to such high-rate ionizing radiation will lead to severe gas aging problem on the MRPC. In order to improve the gas interchange inside the MRPC, we designed a new structure of self-sealed MRPC. It has a much smaller gas volume, which may accelerate the exchange process between the fresh and the polluted gas. The preparation time before the MRPC could work is also largely shortened. A prototype of self-sealed MRPC was produced in Tsinghua University, and it was tested in the CERN SPS Nov 2015 beam test organized by the CBM-TOF group. It showed around 98% efficiency and 60 ps time resolution. Due to the rate limit of 10 kHz/cm2 in this beam test, we cannot make judgement on its performance under extremely high rate. Therefore further studies have to be performed under higher rate in order to study the capability of improving the gas exchange speed of this more flexible and operable sealed MRPC. This will allow that MRPC to be better suited for the high rate environment of TOF system while operating in the experiment.
Vertically-aligned BCN Nanotube Arrays with Superior Performance in Electrochemical capacitors
Zhou, Junshuang; Li, Na; Gao, Faming; Zhao, Yufeng; Hou, Li; Xu, Ziming
2014-01-01
Electrochemical capacitors (EC) have received tremendous interest due to their high potential to satisfy the urgent demand in many advanced applications. The development of new electrode materials is considered to be the most promising approach to enhance the EC performance substantially. Herein, we present a high-capacity capacitor material based on vertically-aligned BC2N nanotube arrays (VA-BC2NNTAs) synthesized by low temperature solvothermal route. The obtained VA-BC2NNTAs display the good aligned nonbuckled tubular structure, which could indeed advantageously enhance capacitor performance. VA-BC2NNTAs exhibit an extremely high specific capacitance, 547 Fg−1, which is about 2–6 times larger than that of the presently available carbon-based materials. Meanwhile, VA-BC2NNTAs maintain an excellent rate capability and high durability. All these characteristics endow VA-BC2NNTAs an alternative promising candidate for an efficient electrode material for electrochemical capacitors (EC). PMID:25124300
Tan, Rui; Gao, Rongtan; Zhao, Yan; Zhang, Mingjian; Xu, Junyi; Yang, Jinlong; Pan, Feng
2016-11-16
A novel type of organic-inorganic hybrid polymer electrolytes with high electrochemical performances around room temperature is formed by hybrid of nanofillers, Y-type oligomer, polyoxyethylene and Li-salt (PBA-Li), of which the T g and T m are significantly lowered by blended heterogeneous polyethers and embedded nanofillers with benefit of the dipole modification to achieve the high Li-ion migration due to more free-volume space. The quasi-solid-state Li-ion batteries based on the LiFePO 4 /15PBA-Li/Li-metal cells present remarkable reversible capacities (133 and 165 mAh g -1 @0.2 C at 30 and 45 °C, respectively), good rate ability and stable cycle performance (141.9 mAh g -1 @0.2 C at 30 °C after 150 cycles).
Hierarchical TiO2/C micro-nano spheres as high-performance anode materials for sodium ion batteries
NASA Astrophysics Data System (ADS)
Ma, Xiao; Zhang, Zhihui; Tian, Jianliya; Xu, Beibei; Ping, Qiushi; Wang, Baofeng
The hierarchical TiO2/C microspheres were obtained via a facile method of in-situ hydrolysis and spray drying. Antase TiO2 nanoparticles were coherent to microspheres TiO2/C due to the pyrolysis of carbon source (PVP). Besides, the favorable electron transfer from carbon to TiO2 improves the electronic conductivity of TiO2 via the presence of Ti-C bond within TiO2/C composite. Charge-discharge tests show that TiO2/C microspheres delivered a good rate capability of 106.1mAhg‑1 at the high current density of 5Ag‑1 and an enhanced cyclic capacity. The superior electrochemical performance could be ascribed to the porous micro-nano structure, smaller crystal size and increased conductivity. The synthesis of TiO2/C microspheres is easy to scale up for satisfying high-performance sodium storage.
APS-U LATTICE DESIGN FOR OFF-AXIS ACCUMULATION
DOE Office of Scientific and Technical Information (OSTI.GOV)
Sun, Yipeng; Borland, M.; Lindberg, R.
2017-06-25
A 67-pm hybrid-seven-bend achromat (H7BA) lattice is being proposed for a future Advanced Photon Source (APS) multi-bend-achromat (MBA) upgrade project. This lattice design pushes for smaller emittance and requires use of a swap-out (on-axis) injection scheme due to limited dynamic acceptance. Alternate lattice design work has also been performed for the APS upgrade to achieve better beam dynamics performance than the nominal APS MBA lattice, in order to allow off-axis accumulation. Two such alternate H7BA lattice designs, which target a still-low emittance of 90 pm, are discussed in detail in this paper. Although the single-particle-dynamics performance is good, simulations ofmore » collective effects indicate that surprising difficulty would be expected accumulating high single-bunch charge in this lattice. The brightness of the 90-pm lattice is also a factor of two lower than the 67-pm H7BA lattice.« less
Transmission loss characteristics of aircraft sidewall systems to control cabin interior noise
NASA Astrophysics Data System (ADS)
Yesil, Oktay; Serati, Paul M.; Hofbeck, Eric V.; Glover, Billy M.
We have explored the possibility of using new, light weight, and acoustically effective materials on aircraft interiors to control noise. The sidewall system elements were evaluated for increased TL in the laboratory. Measured TL for a given configuration, relative to a baseline, was used as an indication of the TL change to be expected for modifications. Test data were in good agreement with the predicted levels. The TL contributions due to all sidewall components were important for interior cabin noise control. Polyimide foam insulation was inferior to fiberglass in the mid-frequency range; however, foam was a better performer at high frequencies. Fiberglass/polyimide foam composite blankets, with less weight, provided noise reductions similar to fiberglass. 'Premium' fiberglass was slightly better performer than the standard fiberglass. Solid fiberglass interior trim panel provided adequate noise performance. Production-type trim attachment design could be improved to control flanking path for sound transmission.
R&D of the CEPC scintillator-tungsten ECAL
NASA Astrophysics Data System (ADS)
Dong, M. Y.
2018-03-01
The circular electron and positron collider (CEPC) was proposed as a future Higgs factory. To meet the physics requirements, a particle flow algorithm-oriented calorimeter system with high energy resolution and precise reconstruction is considered. A sampling calorimeter with scintillator-tungsten sandwich structure is selected as one of the electromagnetic calorimeter (ECAL) options due to its good performance and relatively low cost. We present the design, the test and the optimization of the scintillator module read out by silicon photomultiplier (SiPM), including the design and the development of the electronics. To estimate the performance of the scintillator and SiPM module for particles with different energy, the beam test of a mini detector prototype without tungsten shower material was performed at the E3 beams in Institute of High Energy Physics (IHEP). The results are consistent with the expectation. These studies provide a reference and promote the development of particle flow electromagnetic calorimeter for the CEPC.
Investigation of automated task learning, decomposition and scheduling
NASA Technical Reports Server (NTRS)
Livingston, David L.; Serpen, Gursel; Masti, Chandrashekar L.
1990-01-01
The details and results of research conducted in the application of neural networks to task planning and decomposition are presented. Task planning and decomposition are operations that humans perform in a reasonably efficient manner. Without the use of good heuristics and usually much human interaction, automatic planners and decomposers generally do not perform well due to the intractable nature of the problems under consideration. The human-like performance of neural networks has shown promise for generating acceptable solutions to intractable problems such as planning and decomposition. This was the primary reasoning behind attempting the study. The basis for the work is the use of state machines to model tasks. State machine models provide a useful means for examining the structure of tasks since many formal techniques have been developed for their analysis and synthesis. It is the approach to integrate the strong algebraic foundations of state machines with the heretofore trial-and-error approach to neural network synthesis.
Further weight reduction of applications in long glass reinforced polymers
NASA Astrophysics Data System (ADS)
Yanev, A.; Schijve, W.; Martin, C.; Brands, D.
2014-05-01
Long glass reinforced materials are broadly used in the automotive industry due to their good mechanical performance, competitive price and options for functional integration in order to reduce weight. With rapidly changing environmental requirements, a demand for further weight reduction is growing constantly. Designs in LGF-PP can bring light weight solutions in combination with system cost improvement. There are quite some possibilities for applying weight reduction technologies nowadays. These technologies have to be evaluated based on weight reduction potential, but also on mechanical performance of the end application, where the latter is often the key to success. Different weight reduction technologies are applied to SABIC®STAMAX{trade mark, serif} material, a long glass fiber reinforced polypropylene (LGF-PP), in order to investigate and define best application performance. These techniques include: chemical foaming, physical foaming and thin wall applications. Results from this research will be presented, giving a guideline for your development.
NASA Astrophysics Data System (ADS)
Zhang, Lifeng; Song, Jiajia; Liu, Yi; Yuan, Xiaoyan; Guo, Shouwu
2018-03-01
Developing high energy storage lithium ion batteries (LIBs) using manganese oxides as anodes is an attractive challenge due to their high theoretical capacity and abundant resources. However, the manganese oxides anodes still suffer from the low initial Coulombic efficiency and poor rate performance. Herein, we demonstrate that nano-sized morphological engineering is a facile and effective strategy to improve the electrochemical performance of the manganese dioxide (MnO2) for LIBs. The tailored MnO2 nanoparticles (NPs) exhibit high reversible capacity (1095 mAh g-1 at 100 mA g-1), high initial Coulombic efficiency (94.5%) and good rate capability (464 mAh g-1 at 2000 mA g-1). The enhanced electrochemical performance of MnO2 NPs can be attributed to the presences of numerous electrochemically active sites and interspaces among the NPs.
On analyzing colour constancy approach for improving SURF detector performance
NASA Astrophysics Data System (ADS)
Zulkiey, Mohd Asyraf; Zaki, Wan Mimi Diyana Wan; Hussain, Aini; Mustafa, Mohd. Marzuki
2012-04-01
Robust key point detector plays a crucial role in obtaining a good tracking feature. The main challenge in outdoor tracking is the illumination change due to various reasons such as weather fluctuation and occlusion. This paper approaches the illumination change problem by transforming the input image through colour constancy algorithm before applying the SURF detector. Masked grey world approach is chosen because of its ability to perform well under local as well as global illumination change. Every image is transformed to imitate the canonical illuminant and Gaussian distribution is used to model the global change. The simulation results show that the average number of detected key points have increased by 69.92%. Moreover, the average of improved performance cases far out weight the degradation case where the former is improved by 215.23%. The approach is suitable for tracking implementation where sudden illumination occurs frequently and robust key point detection is needed.
Finite element analysis of composite beam-to-column connection with cold-formed steel section
NASA Astrophysics Data System (ADS)
Firdaus, Muhammad; Saggaff, Anis; Tahir, Mahmood Md
2017-11-01
Cold-formed steel (CFS) sections are well known due to its lightweight and high structural performance which is very popular for building construction. Conventionally, they are used as purlins and side rails in the building envelopes of the industrial buildings. Recent research development on cold-formed steel has shown that the usage is expanded to the use in composite construction. This paper presents the modelling of the proposed composite connection of beam-to-column connection where cold-formed steel of lipped steel section is positioned back-to-back to perform as beam. Reinforcement bars is used to perform the composite action anchoring to the column and part of it is embedded into a slab. The results of the finite element and numerical analysis has showed good agreement. The results show that the proposed composite connection contributes to significant increase to the moment capacity.
Healthcare in Canada's North: Are We Getting Value for Money?
Young, T Kue; Chatwood, Susan; Marchildon, Gregory P
2016-08-01
To determine if Canadians are getting value for money in providing health services to our northern residents. Secondary analyses of data from Statistics Canada, the Canadian Institute of Health Information and territorial government agencies on health status, health expenditures and health system performance indicators. Per capita health expenditures in Canada's northern territories are double that of Canada as a whole and are among the highest in the world. The North lags behind the rest of the country in preventable mortality, hospitalization for ambulatory care sensitive conditions and other performance indicators. The higher health expenditure in the North is to be expected from its unique geography and demography. If the North is not performing as well as Canada, it is not due to lack of money, and policy makers should be concerned about whether healthcare can be as good as it could be. Copyright © 2016 Longwoods Publishing.
Fusion PIC code performance analysis on the Cori KNL system
DOE Office of Scientific and Technical Information (OSTI.GOV)
Koskela, Tuomas S.; Deslippe, Jack; Friesen, Brian
We study the attainable performance of Particle-In-Cell codes on the Cori KNL system by analyzing a miniature particle push application based on the fusion PIC code XGC1. We start from the most basic building blocks of a PIC code and build up the complexity to identify the kernels that cost the most in performance and focus optimization efforts there. Particle push kernels operate at high AI and are not likely to be memory bandwidth or even cache bandwidth bound on KNL. Therefore, we see only minor benefits from the high bandwidth memory available on KNL, and achieving good vectorization ismore » shown to be the most beneficial optimization path with theoretical yield of up to 8x speedup on KNL. In practice we are able to obtain up to a 4x gain from vectorization due to limitations set by the data layout and memory latency.« less
Iterative tailoring of optical quantum states with homodyne measurements.
Etesse, Jean; Kanseri, Bhaskar; Tualle-Brouri, Rosa
2014-12-01
As they can travel long distances, free space optical quantum states are good candidates for carrying information in quantum information technology protocols. These states, however, are often complex to produce and require protocols whose success probability drops quickly with an increase of the mean photon number. Here we propose a new protocol for the generation and growth of arbitrary states, based on one by one coherent adjunctions of the simple state superposition α|0〉 + β|1〉. Due to the nature of the protocol, which allows for the use of quantum memories, it can lead to high performances.
Pang, Huan; Zhang, Yizhou; Cheng, Tao; Lai, Wen-Yong; Huang, Wei
2015-10-14
Uniform manganese hexacyanoferrate hydrate nanocubes are prepared via a simple chemical precipitation method at room temperature. Due to both micro/mesopores of the Prussian blue analogue and nanocubic structures, the manganese hexacyanoferrate hydrate nanocubes allow the efficient charge transfer and mass transport for electrolyte solution and chemical species. Thus, the manganese hexacyanoferrate hydrate nanocube electrode shows a good rate capability and cycling stability for electrochemical capacitors. Furthermore, electrodes modified with manganese hexacyanoferrate hydrate nanocubes demonstrate a sensitive electrochemical response to hydrogen peroxide (H2O2) in buffer solutions with a high selectivity.
Supercapacitor Operating At 200 Degrees Celsius
Borges, Raquel S.; Reddy, Arava Leela Mohana; Rodrigues, Marco-Tulio F.; Gullapalli, Hemtej; Balakrishnan, Kaushik; Silva, Glaura G.; Ajayan, Pulickel M.
2013-01-01
The operating temperatures of current electrochemical energy storage devices are limited due to electrolyte degradation and separator instability at higher temperatures. Here we demonstrate that a tailored mixture of materials can facilitate operation of supercapacitors at record temperatures, as high as 200°C. Composite electrolyte/separator structures made from naturally occurring clay and room temperature ionic liquids, with graphitic carbon electrodes, show stable supercapacitor performance at 200°C with good cyclic stability. Free standing films of such high temperature composite electrolyte systems can become versatile functional membranes in several high temperature energy conversion and storage applications. PMID:23999206
Dynamic surface acoustic response to a thermal expansion source on an anisotropic half space.
Zhao, Peng; Zhao, Ji-Cheng; Weaver, Richard
2013-05-01
The surface displacement response to a distributed thermal expansion source is solved using the reciprocity principle. By convolving the strain Green's function with the thermal stress field created by an ultrafast laser illumination, the complete surface displacement on an anisotropic half space induced by laser absorption is calculated in the time domain. This solution applies to the near field surface displacement due to pulse laser absorption. The solution is validated by performing ultrafast laser pump-probe measurements and showing very good agreement between the measured time-dependent probe beam deflection and the computed surface displacement.
Residential Indoor Temperature Study
DOE Office of Scientific and Technical Information (OSTI.GOV)
Booten, Chuck; Robertson, Joseph; Christensen, Dane
2017-04-07
In this study, we are adding to the body of knowledge around answering the question: What are good assumptions for HVAC set points in U.S. homes? We collected and analyzed indoor temperature data from US homes using funding from the U.S. Department of Energy's Building America (BA) program, due to the program's reliance on accurate energy simulation of homes. Simulations are used to set Building America goals, predict the impact of new building techniques and technologies, inform research objectives, evaluate home performance, optimize efficiency packages to meet savings goals, customize savings approaches to specific climate zones, and myriad other uses.
Calculation with MCNP of capture photon flux in VVER-1000 experimental reactor.
Töre, Candan; Ortego, Pedro
2005-01-01
The aim of this study is to obtain by Monte Carlo method the high energy photon flux due to neutron capture in the internals and vessel layers of the experimental reactor LR-0 located in REZ, Czech Republic, and loaded with VVER-1000 fuel. The calclated neutron, photon and photon to neutron flux ratio are compared with experimental measurements performed with a multi-parameter stilbene detector. The results show clear underestimation of photon flux in downcomer and some overestimation at vessel surface and 1/4 thickness but a good fitting for deeper points in vessel.
Development and application of free pretreatment container steel
NASA Astrophysics Data System (ADS)
Yang, Y.; Liu, Y.; Han, B.; Wei, B.; Wang, S. Z.
2017-12-01
Due to economic and environmental advantages pre-treatment containers have good big development prospects, which can avoid shot blasting processes, and decrease the noise and dust pollution. By analyzing requirements of the container steel surface quality, target oxide scale structure of free pretreatment container steel has been determined. Trial process was carried out, and test results showed that the oxide scale achieved the desired objects, oxide scale with outer thin Fe3O4 layer and inner eutectoid α-Fe+Fe3O4. Salt spray test, second adhesion test, and modeling performance basically corroborated the container feasibility.
Improved epoxy thermosets by the use of poly(ethyleneimine) derivatives
NASA Astrophysics Data System (ADS)
Acebo, Cristina; Ramis, Xavier; Serra, Angels
2017-07-01
Epoxy resins are commonly used as thermosetting materials due to their excellent mechanical properties, high adhesion to many substrates and good heat and chemical resistances. This type of thermosets is intensively used in a wide range of fields, where they act as fiber-reinforced materials, general-purpose adhesives, high-performance coatings and encapsulating materials. These materials are formed by the chemical reaction of multifunctional epoxy monomers forming a polymer network produced through an irreversible way. In this article the improvement of the characteristics of epoxy thermosets using different hyperbranched poly(ethyleneimine) (PEI) derivatives will be explained.
A new type of magnetic gimballed momentum wheel and its application to attitude control in space
NASA Astrophysics Data System (ADS)
Murakami, C.; Ohkami, Y.; Okamoto, O.; Nakajima, A.; Inoue, M.; Tsuchiya, J.; Yabu-uchi, K.; Akishita, S.; Kida, T.
A new type of magnetically suspended gimbal momentum wheel utilizing permanent magnets is described. The bearing was composed of four independent thrust actuators which control the rotor thrust position and gimbal angles cooperatively, so that the bearing comes to have a simple mechanism with high reliability and light weight. The high speed instability problem due to the internal damping was easily overcome by introducing anisotropic radial stiffness. A momentum flywheel with the 3-axis controlled magnetic bearing displays good performance for attitude control of satellite with biased momentum.
How to assess good candidate molecules for self-activated optical power limiting
NASA Astrophysics Data System (ADS)
Lundén, Hampus; Glimsdal, Eirik; Lindgren, Mikael; Lopes, Cesar
2018-03-01
Reverse saturable absorbers have shown great potential to attenuate laser radiation. Good candidate molecules and various particles have successfully been incorporated into different glass matrices, enabling the creation of self-activated filters against damaging laser radiation. Although the performance of such filters has been impressive, work is still ongoing to improve the performance in a wider range of wavelengths and pulse widths. The purpose of this tutorial is, from an optical engineering perspective, to give an understanding of the strengths and weaknesses of this class of smart materials, how relevant photophysical parameters are measured and influence system performance and comment on the pitfalls in experimental evaluation of materials. A numerical population model in combination with simple physical formulas is used to demonstrate system behavior from a performance standpoint. Geometrical reasoning shows the advantage of reverse saturable absorption over nonlinear scattering due to a fraction of scattered light being recollected by imaging system optics. The numerical population model illustrates the importance of the optical power limiting performance during the leading edge of a nanosecond pulse, which is most strongly influenced by changes in the two-photon absorption cross section and the triplet linear absorption cross section for a modeled Pt-acetylide. This tutorial not only targets optical engineers evaluating reverse saturable absorbing materials but also aims to assist researchers with a chemistry background working on optical power limiting materials. We also present photophysical data for a series of coumarins that can be useful for the determination of quantum yields and two-photon cross sections and show examples of characterization of molecules with excited triplet states.
Ankle surgery: focus on arthroscopy.
Cavallo, M; Natali, S; Ruffilli, A; Buda, R; Vannini, F; Castagnini, F; Ferranti, E; Giannini, S
2013-12-01
The ankle joint can be affected by several diseases, with clinical presentation varying from mild pain or swelling to inability, becoming in some cases a serious problem in daily life activities. Arthroscopy is a widely performed procedure in orthopedic surgery, due to the low invasivity compared to the more traditional open field surgery. The ankle joint presents anatomical specificities, like small space and tangential view that make arthroscopy more difficult. From 2000 more than 600 ankle arthroscopies were performed at our institution. The treated pathologies were mostly impingement syndrome and osteochondral lesions, and in lower percentage instabilities and ankle fractures. In the impingement, the AOFAS scores at FU showed an increase compared to scores collected preoperatively, with improvement of symptoms in most of the cases, good or excellent results in 80 % of cases. In ligament injuries, AOFAS score significatively improved at the maximum follow-up. In fractures all patients had an excellent AOFAS score at maximum follow-up, with complete return to their pre-injury activities. In osteochondral injuries, the clinical results showed a progressive improvement over time with the different performed procedures. Control MRI and bioptic samples showed a good regeneration of the cartilage and bone tissue in the lesion site. The encouraging obtained clinical results, in line with the literature, show how the arthroscopic technique, after an adequate learning curve, may represent a precious aid for the orthopedic surgeon and for the patient's outcome. Case series, Level IV.
Fusion of multi-tracer PET images for dose painting.
Lelandais, Benoît; Ruan, Su; Denœux, Thierry; Vera, Pierre; Gardin, Isabelle
2014-10-01
PET imaging with FluoroDesoxyGlucose (FDG) tracer is clinically used for the definition of Biological Target Volumes (BTVs) for radiotherapy. Recently, new tracers, such as FLuoroThymidine (FLT) or FluoroMisonidazol (FMiso), have been proposed. They provide complementary information for the definition of BTVs. Our work is to fuse multi-tracer PET images to obtain a good BTV definition and to help the radiation oncologist in dose painting. Due to the noise and the partial volume effect leading, respectively, to the presence of uncertainty and imprecision in PET images, the segmentation and the fusion of PET images is difficult. In this paper, a framework based on Belief Function Theory (BFT) is proposed for the segmentation of BTV from multi-tracer PET images. The first step is based on an extension of the Evidential C-Means (ECM) algorithm, taking advantage of neighboring voxels for dealing with uncertainty and imprecision in each mono-tracer PET image. Then, imprecision and uncertainty are, respectively, reduced using prior knowledge related to defects in the acquisition system and neighborhood information. Finally, a multi-tracer PET image fusion is performed. The results are represented by a set of parametric maps that provide important information for dose painting. The performances are evaluated on PET phantoms and patient data with lung cancer. Quantitative results show good performance of our method compared with other methods. Copyright © 2014 Elsevier B.V. All rights reserved.
Air-Coupled Low Frequency Ultrasonic Transducers and Arrays with PMN-32%PT Piezoelectric Crystals
Kazys, Rymantas J.; Sliteris, Reimondas; Sestoke, Justina
2017-01-01
Air-coupled ultrasonic techniques are being increasingly used for material characterization, non-destructive evaluation of composite materials using guided waves as well as for distance measurements. Application of those techniques is mainly limited by the big losses of ultrasonic signals due to attenuation and mismatch of the acoustic impedances of ultrasonic transducers and air. One of the ways to solve this problem is by application of novel more efficient piezoelectric materials like lead magnesium niobate-lead titanate (PMN-PT) type crystals. The objective of this research was the development and investigation of low frequency (<50 kHz) wide band air-coupled ultrasonic transducers and arrays with an improved performance using PMN-32%PT crystals. Results of finite element modelling and experimental investigations of the developed transducers and arrays are presented. For improvement of the performance strip-like matching elements made of low acoustic impedance, materials such as polystyrene foams were applied. It allowed to achieve transduction losses for one single element transducer −11.4 dB, what is better than of commercially available air-coupled ultrasonic transducers. Theoretical and experimental investigations of the acoustic fields radiated by the eight element ultrasonic array demonstrated not only a good performance of the array in a pulse mode, but also very good possibilities to electronically focus and steer the ultrasonic beam in space. PMID:28067807
Fast-forward Langevin dynamics with momentum flips
NASA Astrophysics Data System (ADS)
Hijazi, Mahdi; Wilkins, David M.; Ceriotti, Michele
2018-05-01
Stochastic thermostats based on the Langevin equation, in which a system is coupled to an external heat bath, are popular methods for temperature control in molecular dynamics simulations due to their ergodicity and their ease of implementation. Traditionally, these thermostats suffer from sluggish behavior in the limit of high friction, unlike thermostats of the Nosé-Hoover family whose performance degrades more gently in the strong coupling regime. We propose a simple and easy-to-implement modification to the integration scheme of the Langevin algorithm that addresses the fundamental source of the overdamped behavior of high-friction Langevin dynamics: if the action of the thermostat causes the momentum of a particle to change direction, it is flipped back. This fast-forward Langevin equation preserves the momentum distribution and so guarantees the correct equilibrium sampling. It mimics the quadratic behavior of Nosé-Hoover thermostats and displays similarly good performance in the strong coupling limit. We test the efficiency of this scheme by applying it to a 1-dimensional harmonic oscillator, as well as to water and Lennard-Jones polymers. The sampling efficiency of the fast-forward Langevin equation thermostat, measured by the correlation time of relevant system variables, is at least as good as the traditional Langevin thermostat, and in the overdamped regime, the fast-forward thermostat performs much better, improving the efficiency by an order of magnitude at the highest frictions we considered.
Facile synthesis of high strength hot-water wood extract films with oxygen-barrier performance
NASA Astrophysics Data System (ADS)
Chen, Ge-Gu; Fu, Gen-Que; Wang, Xiao-Jun; Gong, Xiao-Dong; Niu, Ya-Shuai; Peng, Feng; Yao, Chun-Li; Sun, Run-Cang
2017-01-01
Biobased nanocomposite films for food packaging with high mechanical strength and good oxygen-barrier performance were developed using a hot-water wood extract (HWE). In this work, a facile approach to produce HWE/montmorillonite (MMT) based nanocomposite films with excellent physical properties is described. The focus of this study was to determine the effects of the MMT content on the structure and mechanical properties of nanocomposites and the effects of carboxymethyl cellulose (CMC) on the physical properties of the HWE-MMT films. The experimental results suggested that the intercalation of HWE and CMC in montmorillonite could produce compact, robust films with a nacre-like structure and multifunctional characteristics. This results of this study showed that the mechanical properties of the film designated FCMC0.05 (91.5 MPa) were dramatically enhanced because the proportion of HWE, MMT and CMC was 1:1.5:0.05. In addition, the optimized films exhibited an oxygen permeability below 2.0 cm3 μm/day·m2·kPa, as well as good thermal stability due to the small amount of CMC. These results provide a comprehensive understanding for further development of high-performance nanocomposites which are based on natural polymers (HWE) and assembled layered clays (MMT). These films offer great potential in the field of sustainable packaging.
Facile synthesis of high strength hot-water wood extract films with oxygen-barrier performance
Chen, Ge-Gu; Fu, Gen-Que; Wang, Xiao-Jun; Gong, Xiao-Dong; Niu, Ya-Shuai; Peng, Feng; Yao, Chun-Li; Sun, Run-Cang
2017-01-01
Biobased nanocomposite films for food packaging with high mechanical strength and good oxygen-barrier performance were developed using a hot-water wood extract (HWE). In this work, a facile approach to produce HWE/montmorillonite (MMT) based nanocomposite films with excellent physical properties is described. The focus of this study was to determine the effects of the MMT content on the structure and mechanical properties of nanocomposites and the effects of carboxymethyl cellulose (CMC) on the physical properties of the HWE-MMT films. The experimental results suggested that the intercalation of HWE and CMC in montmorillonite could produce compact, robust films with a nacre-like structure and multifunctional characteristics. This results of this study showed that the mechanical properties of the film designated FCMC0.05 (91.5 MPa) were dramatically enhanced because the proportion of HWE, MMT and CMC was 1:1.5:0.05. In addition, the optimized films exhibited an oxygen permeability below 2.0 cm3 μm/day·m2·kPa, as well as good thermal stability due to the small amount of CMC. These results provide a comprehensive understanding for further development of high-performance nanocomposites which are based on natural polymers (HWE) and assembled layered clays (MMT). These films offer great potential in the field of sustainable packaging. PMID:28112259
Jiang, Mengjin; Zhu, Jiadeng; Chen, Chen; Lu, Yao; Ge, Yeqian; Zhang, Xiangwu
2016-02-10
Gel polymer electrolytes (GPEs) have been studied for preparing flexible and compact electrochemical energy storage devices. However, the preparation and use of GPEs are complex, and most GPEs prepared through traditional methods do not have good wettability with the electrodes, which retard them from achieving their performance potential. In this study, these problems are addressed by conceiving and implementing a simple, but effective, method of electrodepositing poly(vinyl alcohol) potassium borate (PVAPB) GPEs directly onto the surfaces of active carbon electrodes for electrochemical supercapacitors. PVAPB GPEs serve as both the electrolyte and the separator in the assembled supercapacitors, and their scale and shape are determined solely by the geometry of the electrodes. PVAPB GPEs have good bonding to the active electrode materials, leading to excellent and stable electrochemical performance of the supercapacitors. The electrochemical performance of PVAPB GPEs and supercapacitors can be manipulated simply by adjusting the concentration of KCl salt used during the electrodeposition process. With a 0.9 M KCl concentration, the as-prepared supercapacitors deliver a specific capacitance of 65.9 F g(-1) at a current density of 0.1 A g(-1) and retain more than 95% capacitance after 2000 charge/discharge cycles at a current density of 1 A g(-1). These supercapacitors also exhibit intelligent high voltage self-protection function due to the electrolysis-induced cross-linking effect of PVAPB GPEs.
Panda, Samiran; Das, Aritra; Samanta, Saheli
2014-08-11
The debate on the relevance of rotavirus vaccine to immunization program in India, where 27 million children are born every year, rages on. We synthesized the issues raised during these debates and reviewed the current literature to identify themes that could inform public health policy decision. The paradigm we used integrated disease burden data, host and environmental factors, vaccine efficacy, immunization program issues, and economic considerations. Our synthesis reveals that substantive country specific information on disease burden and economic impact of rotavirus illness in India is constrained by lack of public discussion and qualitative studies on mothers' perceptions of the vaccine in concern. The need to improve the performance of current immunization program against six major vaccine preventable diseases (tuberculosis, diphtheria, tetanus, pertussis, polio, and measles) is often cited as a priority over introduction of rotavirus vaccine. Health in India being a state subject, we emphasize that the states which are in a position to reap the benefit of rotavirus vaccine, due to their good immunization program performance, should not be restrained from doing so. Meanwhile, the poorly performing states should step up their vaccination program and increase immunization coverage. Scientific, ethical and societal concerns captured through multiple sources indicate that the introduction of rotavirus vaccine would be a good investment for India. Copyright © 2014. Published by Elsevier Ltd.
Fretting wear study of surface modified Ni-Ti shape memory alloy.
Tan, L; Crone, W C; Sridharan, K
2002-05-01
A combination of shape memory characteristics, pseudoelasticity, and good damping properties make near-equiatomic nickel-titanium (Ni-Ti) alloy a desirable candidate material for certain biomedical device applications. The alloy has moderately good wear resistance, however, further improvements in this regard would be beneficial from the perspective of reducing wear debris generation, improving biocompatibility, and preventing failure during service. Fretting wear tests of Ni-Ti in both austenitic and martensitic microstructural conditions were performed with the goal of simulating wear which medical devices such as stents may experience during surgical implantation or service. The tests were performed using a stainless steel stylus counter-wearing surface under dry conditions and also with artificial plasma containing 80 g/L albumen protein as lubricant. Additionally, the research explores the feasibility of surface modification by sequential ion implantation with argon and oxygen to enhance the wear characteristics of the Ni-Ti alloy. Each of these implantations was performed to a dose of 3 x 10(17) atom/cm(2) and an energy of 50 kV, using the plasma source ion implantation process. Improvements in wear resistance were observed for the austenitic samples implanted with argon and oxygen. Ion implantation with argon also reduced the surface Ni content with respect to Ti due to differential sputtering rates of the two elements, an effect that points toward improved biocompatibility.
Do quality indicators for general practice teaching practices predict good outcomes for students?
Bartlett, Maggie; Potts, Jessica; McKinley, Bob
2016-07-01
Keele medical students spend 113 days in general practices over our five-year programme. We collect practice data thought to indicate good quality teaching. We explored the relationships between these data and two outcomes for students; Objective Structured Clinical Examination (OSCE) scores and feedback regarding the placements. Though both are surrogate markers of good teaching, they are widely used. We collated practice and outcome data for one academic year. Two separate statistical analyses were carried out: (1) to determine how much of the variation seen in the OSCE scores was due to the effect of the practice and how much to the individual student. (2) to identify practice characteristics with a relationship to student feedback scores. (1) OSCE performance: 268 students in 90 practices: six quality indicators independently influenced the OSCE score, though without linear relationships and not to statistical significance. (2) Student satisfaction: 144 students in 69 practices: student feedback scores are not influenced by practice characteristics. The relationships between the quality indicators we collect for practices and outcomes for students are not clear. It may be that neither the quality indicators nor the outcome measures are reliable enough to inform decisions about practices' suitability for teaching.
Key composition optimization of meat processed protein source by vacuum freeze-drying technology.
Ma, Yan; Wu, Xingzhuang; Zhang, Qi; Giovanni, Vigna; Meng, Xianjun
2018-05-01
Vacuum freeze-drying technology is a high technology content, a wide range of knowledge of technology in the field of drying technology is involved, it is also a method of the most complex drying equipment, the largest energy consumption, the highest cost of drying method, but due to the particularity of its dry goods: the freeze-drying food has the advantages of complex water performance is good, cooler and luster of freezing and drying food to maintain good products, less nutrient loss, light weight, easy to carry transportation, easy to long-term preservation, and on the quality is far superior to the obvious advantages of other dried food, making it become the forefront of drying technology research and development. The freeze-drying process of Chinese style ham and western Germany fruit tree tenderloin is studied in this paper, their eutectic point, melting point and collapse temperature, freeze-drying curve and its heat and mass transfer characteristics are got, then the precool temperature and the highest limiting temperature of sublimation interface are determined. The effect of system pressure on freeze-dried rate in freeze-drying process is discussed, and the method of regulating pressure circularly is determined.
Cywinski, Adam; Piwonska-Lobermajer, Anna; Penter, Sandra
2016-08-01
A retrospective analysis of visual function and postoperative complaints in patients after posterior vitrectomy and multifocal Mplus or MplusX intraocular lens implantation. 14 patients (14 eyes) were enrolled in the study. All patients underwent posterior vitrectomy due to underlying retinal pathologies. A combined procedure of phacovitrectomy was performed in some patients, whereas others underwent a separate cataract extraction as a second stage of treatment. The Mplus or MplusX intraocular lenses were implanted in all cases and the postoperative visual function and patient complaints were analysed. Multifocal lens explantation was not necessary in any case. Good uncorrected distance and near visual acuity was achieved in most cases. When implanted prior to vitrectomy, the intraocular lenses did not limit the view into the posterior segment, so precise manipulations within the macula and peripheral retina were feasible. The right choice between Mplus and MplusX minimises the rate of postoperative complaints. Conslusions: The multifocal Mplus and MplusX intraocular lenses offer a good alternative for patients who need posterior vitrectomy and still want to achieve good uncorrected distance and near visual acuity.
Cesaretti, Manuela; Trotta, Manuela; Leale, Irene; Minetti, Giuseppe Antonio; Cittadini, Giuseppe; Montecucco, Fabrizio; Camerini, Giovanni Bruno; Borgonovo, Giacomo
2018-01-01
The mobile cecum syndrome includes a spectrum of conditions. The cecal volvulus represents the acute form, with typical feature of a bowel obstruction that needs immediate operative treatment. On the other hand, a chronic form of mobile cecum syndrome which is the most common form reported a history of intermittent crampy abdominal pain, distension, and constipation. In this study, five patients came to our attention during the last ten years, presenting different symptoms due to a mobile cecum. All patients were investigated by several diagnostic techniques according to the specific clinical setting. All patients were found to have the cecum and ascending colon unattached to the posterior peritoneum. Surgery was the treatment of choice. In our experience, the best diagnostic technique was computed tomography scan, especially if performed in the Trendelenburg position. We also propose virtual colonoscopy as a good option for diagnosis (in patients with chronic syndrome) and follow-up after surgery. In conclusion, laparoscopic approach guaranteed a good result, with no symptoms of recurrence, in both acute and elective treatments. The diagnosis of mobile cecum needs a high index of suspicion and a targeted radiological investigation. Surgery, especially laparoscopic cecopexy and appendectomy, is the recommended treatment.
Extreme hydronephrosis due to uretropelvic junction obstruction in infant (case report).
Krzemień, Grażyna; Szmigielska, Agnieszka; Bombiński, Przemysław; Barczuk, Marzena; Biejat, Agnieszka; Warchoł, Stanisław; Dudek-Warchoł, Teresa
2016-01-01
Hydronephrosis is the one of the most common congenital abnormalities of urinary tract. The left kidney is more commonly affected than the right side and is more common in males. To determine the role of ultrasonography, renal dynamic scintigraphy and lowerdose computed tomography urography in preoperative diagnostic workup of infant with extreme hydronephrosis. We presented the boy with antenatally diagnosed hydronephrosis. In serial, postnatal ultrasonography, renal scintigraphy and computed tomography urography we observed slightly declining function in the dilated kidney and increasing pelvic dilatation. Pyeloplasty was performed at the age of four months with good result. Results of ultrasonography and renal dynamic scintigraphy in child with extreme hydronephrosis can be difficult to asses, therefore before the surgical procedure a lower-dose computed tomography urography should be performed.
Learning moment-based fast local binary descriptor
NASA Astrophysics Data System (ADS)
Bellarbi, Abdelkader; Zenati, Nadia; Otmane, Samir; Belghit, Hayet
2017-03-01
Recently, binary descriptors have attracted significant attention due to their speed and low memory consumption; however, using intensity differences to calculate the binary descriptive vector is not efficient enough. We propose an approach to binary description called POLAR_MOBIL, in which we perform binary tests between geometrical and statistical information using moments in the patch instead of the classical intensity binary test. In addition, we introduce a learning technique used to select an optimized set of binary tests with low correlation and high variance. This approach offers high distinctiveness against affine transformations and appearance changes. An extensive evaluation on well-known benchmark datasets reveals the robustness and the effectiveness of the proposed descriptor, as well as its good performance in terms of low computation complexity when compared with state-of-the-art real-time local descriptors.
Performance and Mix Measurements of Indirect Drive Cu-Doped Be Implosions
DOE Office of Scientific and Technical Information (OSTI.GOV)
Casey, D. T.; Woods, D. T.; Smalyuk, V. A.
2015-05-19
The ablator couples energy between the driver and fusion fuel in inertial confinement fusion (ICF). Because of its low opacity, high solid density, and material properties, beryllium has long been considered an ideal ablator for ICF ignition experiments at the National Ignition Facility. We report here the first indirect drive Be implosions driven with shaped laser pulses and diagnosed with fusion yield at the OMEGA laser. The results show good performance with an average DD neutron yield of ~2 × 10⁹ at a convergence ratio of R₀/R ~ 10 and little impact due to the growth of hydrodynamic instabilities andmore » mix. In addition, the effect of adding an inner liner of W between the Be and DD is demonstrated.« less
Verification testing of the PKI collector at Sandia National Laboratories, Albuquerque, New Mexico
NASA Technical Reports Server (NTRS)
Hauger, J. S.; Pond, S. L.
1982-01-01
Verification testing of a solar collector was undertaken prior to its operation as part of an industrial process heat plant at Capitol Concrete Products in Topeka, Kansas. Testing was performed at a control plant installed at Sandia National Laboratory, Albuquerque, New Mexico (SNLA). Early results show that plant performance is even better than anticipated and far in excess of test criteria. Overall plant efficiencies of 65 to 80 percent were typical during hours of good insolation. A number of flaws and imperfections were detected during operability testing, the most important being a problem in elevation drive alignment due to a manufacturing error. All problems were corrected as they occurred and the plant, with over 40 hours of operation, is currently continuing operability testing in a wholly-automatic mode.
Verification testing of the PKI collector at Sandia National Laboratories, Albuquerque, New Mexico
NASA Astrophysics Data System (ADS)
Hauger, J. S.; Pond, S. L.
1982-07-01
Verification testing of a solar collector was undertaken prior to its operation as part of an industrial process heat plant at Capitol Concrete Products in Topeka, Kansas. Testing was performed at a control plant installed at Sandia National Laboratory, Albuquerque, New Mexico (SNLA). Early results show that plant performance is even better than anticipated and far in excess of test criteria. Overall plant efficiencies of 65 to 80 percent were typical during hours of good insolation. A number of flaws and imperfections were detected during operability testing, the most important being a problem in elevation drive alignment due to a manufacturing error. All problems were corrected as they occurred and the plant, with over 40 hours of operation, is currently continuing operability testing in a wholly-automatic mode.
A robust low-rate coding scheme for packet video
NASA Technical Reports Server (NTRS)
Chen, Y. C.; Sayood, Khalid; Nelson, D. J.; Arikan, E. (Editor)
1991-01-01
Due to the rapidly evolving field of image processing and networking, video information promises to be an important part of telecommunication systems. Although up to now video transmission has been transported mainly over circuit-switched networks, it is likely that packet-switched networks will dominate the communication world in the near future. Asynchronous transfer mode (ATM) techniques in broadband-ISDN can provide a flexible, independent and high performance environment for video communication. For this paper, the network simulator was used only as a channel in this simulation. Mixture blocking coding with progressive transmission (MBCPT) has been investigated for use over packet networks and has been found to provide high compression rate with good visual performance, robustness to packet loss, tractable integration with network mechanics and simplicity in parallel implementation.
29 CFR 452.88 - Resumption of good standing.
Code of Federal Regulations, 2010 CFR
2010-07-01
... DISCLOSURE ACT OF 1959 Right To Vote § 452.88 Resumption of good standing. While it is permissible for a labor organization to deny the right to vote to those delinquent in paying their dues (with the... 29 Labor 2 2010-07-01 2010-07-01 false Resumption of good standing. 452.88 Section 452.88 Labor...
An alternative to traditional goodness-of-fit tests for discretely measured continuous data
KaDonna C. Randolph; Bill Seaver
2007-01-01
Traditional goodness-of-fit tests such as the Kolmogorov-Smirnov and x2 tests are easily applied to data of the continuous or discrete type, respectively. Occasionally, however, the case arises when continuous data are recorded into discrete categories due to an imprecise measurement system. In this instance, the traditional goodness-of-fit...
Perceptual and Acoustic Analyses of Good Voice Quality in Male Radio Performers.
Warhurst, Samantha; Madill, Catherine; McCabe, Patricia; Ternström, Sten; Yiu, Edwin; Heard, Robert
2017-03-01
Good voice quality is an asset to professional voice users, including radio performers. We examined whether (1) voices could be reliably categorized as good for the radio and (2) these categories could be predicted using acoustic measures. Male radio performers (n = 24) and age-matched male controls performed "The Rainbow Passage" as if presenting on the radio. Voice samples were rated using a three-stage paired-comparison paradigm by 51 naive listeners and perceptual categories were identified (Study 1), and then analyzed for fundamental frequency, long-term average spectrum, cepstral peak prominence, and pause or spoken-phrase duration (Study 2). Study 1: Good inter-judge reliability was found for perceptual judgments of the best 15 voices (good for radio category, 14/15 = radio performers), but agreement on the remaining 33 voices (unranked category) was poor. Study 2: Discriminant function analyses showed that the SD standard deviation of sounded portion duration, equivalent sound level, and smoothed cepstral peak prominence predicted membership of categories with moderate accuracy (R 2 = 0.328). Radio performers are heterogeneous for voice quality; good voice quality was judged reliably in only 14 out of 24 radio performers. Current acoustic analyses detected some of the relevant signal properties that were salient in these judgments. More refined perceptual analysis and the use of other perceptual methods might provide more information on the complex nature of judging good voices. Copyright © 2017 The Voice Foundation. Published by Elsevier Inc. All rights reserved.
NASA Astrophysics Data System (ADS)
Zhang, Yongyong; Gao, Yang; Yu, Qiang
2017-09-01
Agricultural nitrogen loss becomes an increasingly important source of water quality deterioration and eutrophication, even threatens water safety for humanity. Nitrogen dynamic mechanism is still too complicated to be well captured at watershed scale due to its multiple existence forms and instability, disturbance of agricultural management practices. Stereoscopic agriculture is a novel agricultural planting pattern to efficiently use local natural resources (e.g., water, land, sunshine, heat and fertilizer). It is widely promoted as a high yield system and can obtain considerable economic benefits, particularly in China. However, its environmental quality implication is not clear. In our study, Qianyanzhou station is famous for its stereoscopic agriculture pattern of Southern China, and an experimental watershed was selected as our study area. Regional characteristics of runoff and nitrogen losses were simulated by an integrated water system model (HEQM) with multi-objective calibration, and multiple agriculture practices were assessed to find the effective approach for the reduction of diffuse nitrogen losses. Results showed that daily variations of runoff and nitrogen forms were well reproduced throughout watershed, i.e., satisfactory performances for ammonium and nitrate nitrogen (NH4-N and NO3-N) loads, good performances for runoff and organic nitrogen (ON) load, and very good performance for total nitrogen (TN) load. The average loss coefficient was 62.74 kg/ha for NH4-N, 0.98 kg/ha for NO3-N, 0.0004 kg/ha for ON and 63.80 kg/ha for TN. The dominating form of nitrogen losses was NH4-N due to the applied fertilizers, and the most dramatic zones aggregated in the middle and downstream regions covered by paddy and orange orchard. In order to control diffuse nitrogen losses, the most effective practices for Qianyanzhou stereoscopic agriculture pattern were to reduce farmland planting scale in the valley by afforestation, particularly for orchard in the downstream regions, followed by fertilizer application optimization.
Du, Jun; Zhou, Gang; Zhang, Haiming; Cheng, Chao; Ma, Jianmin; Wei, Weifeng; Chen, Libao; Wang, Taihong
2013-08-14
NiCo2O4 with higher specific capacitance is an excellent pseudocapacitive material. However, the bulk NiCo2O4 material prevents the achievement of high energy desity and great rate performance due to the limited electroactive surface area. In this work, NiCo2O4 nanosheet arrays were deposited on flexible carbon fabric (CF) as a high-performance electrode for supercapacitors. The NiCo2O4 arrays were constructed by interconnected ultrathin nanosheets (10 nm) with many interparticle pores. The porous feature of NiCo2O4 nanosheets increases the amount of electroactive sites and facilitates the electrolyte penetration. Hence, the NiCo2O4/CF composites exhibited a high specific capacitance of 2658 F g(-1) (2 A g(-1)), good rate performance, and superior cycling life, suggesting the NiCo2O4/CF is a promising electrode material for flexible electrochemical capacitors.
NASA Astrophysics Data System (ADS)
Sun, Xiuting; Jing, Xingjian
2016-12-01
This study investigates theoretically and experimentally a vibration isolator constructed by an n-layer Scissor-Like Structure (SLS), focusing on the analysis and design of nonlinear stiffness and damping characteristics for advantageous isolation performance in both orthogonal directions. With the mathematical modeling, the influence incurred by different structural parameters on system isolation performance is studied. It is shown that, (a) nonlinear high-static-low-dynamic stiffness and damping characteristics can be seen such that the system can achieve good isolation performance in both directions, (b) an anti-resonance frequency band exists due to the coupling effect between the linear and nonlinear stiffness in the two orthogonal directions within the structure, and (c) all these performances are designable with several structural parameters. The advantages of the proposed system are shown through comparisons with an existing quasi-zero-stiffness vibration isolator (QZS-VI) and a traditional mass-spring-damper vibration isolator (MSD-VI), and further validated by experimental results.
Monitoring of computing resource utilization of the ATLAS experiment
NASA Astrophysics Data System (ADS)
Rousseau, David; Dimitrov, Gancho; Vukotic, Ilija; Aidel, Osman; Schaffer, Rd; Albrand, Solveig
2012-12-01
Due to the good performance of the LHC accelerator, the ATLAS experiment has seen higher than anticipated levels for both the event rate and the average number of interactions per bunch crossing. In order to respond to these changing requirements, the current and future usage of CPU, memory and disk resources has to be monitored, understood and acted upon. This requires data collection at a fairly fine level of granularity: the performance of each object written and each algorithm run, as well as a dozen per-job variables, are gathered for the different processing steps of Monte Carlo generation and simulation and the reconstruction of both data and Monte Carlo. We present a system to collect and visualize the data from both the online Tier-0 system and distributed grid production jobs. Around 40 GB of performance data are expected from up to 200k jobs per day, thus making performance optimization of the underlying Oracle database of utmost importance.
Wu, Yadong; Wang, Fang; Huang, Yudong
2018-05-01
Hemorrhage remains a leading cause of death after trauma, and developing a hemostat with excellent performance and good biosecurity is an extremely active area of research and commercial product development. Although oxidized regenerated cellulose (ORC) has been developed to address these problems, it is not always efficient and its biosecurity is not perfect. We aimed to refine ORC via a simple and mild neutralization method. The prepared neutralized oxidized regenerated cellulose (NORC) showed a superior gel property due to its chemical structure. The biological performance of both ORC and NORC was systematically evaluated; the results showed that ORC would induce erythema and edema in the irritation test, whereas NORC did not cause any adverse inflammation, indicating NORC had desirable biocompatibility. We further demonstrated that NORC confirmed to the toxicity requirements of International Organization for Standardization (ISO) standards; however, ORC showed an unacceptable cytotoxicity. The rabbit hepatic defect model stated that NORC exhibited better ability of hemostasis, which was attributed to its significant gel performance in physiological environment.
NASA Astrophysics Data System (ADS)
Kannan, Aravindaraj G.; Samuthirapandian, Amaresh; Kim, Dong-Won
2017-01-01
Hierarchically porous graphene nanosheets co-doped with nitrogen and sulfur are synthesized via a simple hydrothermal method, followed by a pore activation step. Pore architectures are controlled by varying the ratio of chemical activation agents to graphene, and its influence on the capacitive performance is evaluated. The electric double layer capacitor (EDLC) assembled with optimized dual-doped graphene delivers a high specific capacitance of 146.6 F g-1 at a current density of 0.8 A g-1, which is higher than that of cells with un-doped and single-heteroatom doped graphene. The EDLC with dual-doped graphene electrodes exhibits stable cycling performance with a capacitance retention of 94.5% after 25,000 cycles at a current density of 3.2 A g-1. Such a good performance can be attributed to synergistic effects due to co-doping of the graphene nanosheets and the presence of hierarchical porous structures.
NASA Astrophysics Data System (ADS)
Takei, Satoshi; Sakaida, Yasushi; Shinjo, Tetsuya; Hashimoto, Keisuke; Nakajima, Yasuyuki
2008-03-01
The present paper describes a novel class of bottom antireflective coating (BARC) and gap fill materials using dextrin derivatives. The general trend of interconnect fabrication for such a high performance LSI is to apply cupper (Cu)/ low-dielectric-constant (low-k) interconnect to reduce RC delay. A via-first dual damascene process is one of the most promising processes to fabricate Cu/ low-k interconnect due to its wide miss-alignment margin. The sacrificial materials containing dextrin derivatives under resist for lithography were developed in via-first dual damascene process. The dextrin derivatives in this study was obtained by the esterification of the hydroxyl groups of dextrin resulting in improved solubility in the resist solvents such as propylene glycol monomethylether, propylene glycol monomethylether acetate, and ethyl lactate due to avoid the issue of defects that were caused by incompatability. The etch rate of our developed BARC and gap fill materials using dextrin derivatives was more than two times faster than one of the ArF resists evaluated in a CF4 gas condition using reactive ion etching. The improved etch performance was also verified by comparison with poly(hydroxystyrene), acrylate-type materials and latest low-k materials as a reference. In addition to superior etch performance, these materials showed good resist profiles and via filling performance without voids in via holes.
NASA Astrophysics Data System (ADS)
Zhang, Chuan; Luo, Wenjun; Wen, Xin; Guan, Zhongjie; Zou, Zhigang
2017-11-01
P-type Cu(In,Ga)S2 semiconductors are promising candidates to be used as photocathodes for solar water splitting. Porous structures have been widely used to improve the performances of photoelectrodes due to good minority carrier transport. However, a porous photoelectrode has longer transport distance of majority carriers, which limits its performance. Controlling pore volume of a photoelectrode can balance minority and majority carrier transport and improve the performance. Here, a porous Cu(In,Ga)S2 film is prepared by facile spin-coating method. The pore volume of Cu(In,Ga)S2 film is controlled by adjusting relative humidity (RH) of air during spin-coating process. Further studies suggest that polyvinyl acetate (PVAc) in precursor solution is a humidity sensitive polymer and plays a key role to form different pore volume. The 40% RH sample has the best performance due to its optimum pore volume. After further coated with CdS surface passivation layer and Pt electrocatalyst on the surface, a 40% RH Cu(In,Ga)S2 photocathode indicates a photocurrent density of 8.6 mA cm-2 at 0 V RHE, which is one of the highest photocurrents of Cu(In,Ga)S2 photocathodes. This new strategy for adjusting pore volume is also suitable to prepare other solution-processed inorganic materials.
McTwo: a two-step feature selection algorithm based on maximal information coefficient.
Ge, Ruiquan; Zhou, Manli; Luo, Youxi; Meng, Qinghan; Mai, Guoqin; Ma, Dongli; Wang, Guoqing; Zhou, Fengfeng
2016-03-23
High-throughput bio-OMIC technologies are producing high-dimension data from bio-samples at an ever increasing rate, whereas the training sample number in a traditional experiment remains small due to various difficulties. This "large p, small n" paradigm in the area of biomedical "big data" may be at least partly solved by feature selection algorithms, which select only features significantly associated with phenotypes. Feature selection is an NP-hard problem. Due to the exponentially increased time requirement for finding the globally optimal solution, all the existing feature selection algorithms employ heuristic rules to find locally optimal solutions, and their solutions achieve different performances on different datasets. This work describes a feature selection algorithm based on a recently published correlation measurement, Maximal Information Coefficient (MIC). The proposed algorithm, McTwo, aims to select features associated with phenotypes, independently of each other, and achieving high classification performance of the nearest neighbor algorithm. Based on the comparative study of 17 datasets, McTwo performs about as well as or better than existing algorithms, with significantly reduced numbers of selected features. The features selected by McTwo also appear to have particular biomedical relevance to the phenotypes from the literature. McTwo selects a feature subset with very good classification performance, as well as a small feature number. So McTwo may represent a complementary feature selection algorithm for the high-dimensional biomedical datasets.
Norms and the Perception of Events
1992-01-31
Experimental Psychology: Human Perception and Performance. 12, 1986, 445-454. Brickman, P., and D.T. Campbell. Hedonic relativism and planning the good ...interesting problem, which we plan to explore in further work. Table 1-3 presents results for conditions involving objects, actions and changes. We...following stem completion appeared: Alfred’s performance on the fourth afternoon was [] Very Good [I Good [] Fairly Good [I Nothing Special [] Rather Bad
45 CFR 95.28 - What a waiver request for good cause must include.
Code of Federal Regulations, 2010 CFR
2010-10-01
... GENERAL ADMINISTRATION-GRANT PROGRAMS (PUBLIC ASSISTANCE, MEDICAL ASSISTANCE AND STATE CHILDREN'S HEALTH... claim is for good cause as defined in § 95.22 and not due to neglect or administrative inadequacy. If...
Bayesian spatiotemporal crash frequency models with mixture components for space-time interactions.
Cheng, Wen; Gill, Gurdiljot Singh; Zhang, Yongping; Cao, Zhong
2018-03-01
The traffic safety research has developed spatiotemporal models to explore the variations in the spatial pattern of crash risk over time. Many studies observed notable benefits associated with the inclusion of spatial and temporal correlation and their interactions. However, the safety literature lacks sufficient research for the comparison of different temporal treatments and their interaction with spatial component. This study developed four spatiotemporal models with varying complexity due to the different temporal treatments such as (I) linear time trend; (II) quadratic time trend; (III) Autoregressive-1 (AR-1); and (IV) time adjacency. Moreover, the study introduced a flexible two-component mixture for the space-time interaction which allows greater flexibility compared to the traditional linear space-time interaction. The mixture component allows the accommodation of global space-time interaction as well as the departures from the overall spatial and temporal risk patterns. This study performed a comprehensive assessment of mixture models based on the diverse criteria pertaining to goodness-of-fit, cross-validation and evaluation based on in-sample data for predictive accuracy of crash estimates. The assessment of model performance in terms of goodness-of-fit clearly established the superiority of the time-adjacency specification which was evidently more complex due to the addition of information borrowed from neighboring years, but this addition of parameters allowed significant advantage at posterior deviance which subsequently benefited overall fit to crash data. The Base models were also developed to study the comparison between the proposed mixture and traditional space-time components for each temporal model. The mixture models consistently outperformed the corresponding Base models due to the advantages of much lower deviance. For cross-validation comparison of predictive accuracy, linear time trend model was adjudged the best as it recorded the highest value of log pseudo marginal likelihood (LPML). Four other evaluation criteria were considered for typical validation using the same data for model development. Under each criterion, observed crash counts were compared with three types of data containing Bayesian estimated, normal predicted, and model replicated ones. The linear model again performed the best in most scenarios except one case of using model replicated data and two cases involving prediction without including random effects. These phenomena indicated the mediocre performance of linear trend when random effects were excluded for evaluation. This might be due to the flexible mixture space-time interaction which can efficiently absorb the residual variability escaping from the predictable part of the model. The comparison of Base and mixture models in terms of prediction accuracy further bolstered the superiority of the mixture models as the mixture ones generated more precise estimated crash counts across all four models, suggesting that the advantages associated with mixture component at model fit were transferable to prediction accuracy. Finally, the residual analysis demonstrated the consistently superior performance of random effect models which validates the importance of incorporating the correlation structures to account for unobserved heterogeneity. Copyright © 2017 Elsevier Ltd. All rights reserved.
Cochlear implantation in patients with bilateral cochlear trauma.
Serin, Gediz Murat; Derinsu, Ufuk; Sari, Murat; Gergin, Ozgül; Ciprut, Ayça; Akdaş, Ferda; Batman, Cağlar
2010-01-01
Temporal bone fracture, which involves the otic capsule, can lead to complete loss of auditory and vestibular functions, whereas the patients without fractures may experience profound sensorineural hearing loss due to cochlear concussion. Cochlear implant is indicated in profound sensorineural hearing loss due to cochlear trauma but who still have an intact auditory nerve. This is a retrospective review study. We report 5 cases of postlingually deafened patients caused by cochlear trauma, who underwent cochlear implantation. Preoperative and postoperative hearing performance will be presented. These patients are cochlear implanted after the cochlear trauma in our department between 2001 and 2006. All patients performed very well with their implants, obtained open-set speech understanding. They all became good telephone users after implantation. Their performance in speech understanding was comparable to standard postlingual adult patients implanted. Cochlear implantation is an effective aural rehabilitation in profound sensorineural hearing loss caused by temporal bone trauma. Preoperative temporal bone computed tomography, magnetic resonance imaging, and promontorium stimulation testing are necessary to make decision for the surgery and to determine the side to be implanted. Surgery could be challenging and complicated because of anatomical irregularity. Moreover, fibrosis and partial or total ossification within the cochlea must be expected. Copyright 2010. Published by Elsevier Inc.
Shi, Peipei; Li, Li; Hua, Li; Qian, Qianqian; Wang, Pengfei; Zhou, Jinyuan; Sun, Gengzhi; Huang, Wei
2017-01-24
Solid-state fiber-based supercapacitors have been considered promising energy storage devices for wearable electronics due to their lightweight and amenability to be woven into textiles. Efforts have been made to fabricate a high performance fiber electrode by depositing pseudocapacitive materials on the outer surface of carbonaceous fiber, for example, crystalline manganese oxide/multiwalled carbon nanotubes (MnO 2 /MWCNTs). However, a key challenge remaining is to achieve high specific capacitance and energy density without compromising the high rate capability and cycling stability. In addition, amorphous MnO 2 is actually preferred due to its disordered structure and has been proven to exhibit superior electrochemical performance over the crystalline one. Herein, by incorporating amorphous MnO 2 onto a well-aligned MWCNT sheet followed by twisting, we design an amorphous MnO 2 @MWCNT fiber, in which amorphous MnO 2 nanoparticles are distributed in MWCNT fiber uniformly. The proposed structure gives the amorphous MnO 2 @MWCNT fiber good mechanical reliability, high electrical conductivity, and fast ion-diffusion. Solid-state supercapacitor based on amorphous MnO 2 @MWCNT fibers exhibits improved energy density, superior rate capability, exceptional cycling stability, and excellent flexibility. This study provides a strategy to design a high performance fiber electrode with microstructure control for wearable energy storage devices.
Percutaneous treatment of transplant renal artery stenosis in children.
Repetto, Horacio A; Rodríguez-Rilo, Laila; Mendaro, Esteban; Basso, Laura; Galvez, Hugo; Morrone, Gabriela; Vazquez, Luis A
2004-12-01
Percutaneous treatment of renal artery stenosis (RAS) is an accepted procedure and numerous reports have been published. However, experience with its use in RAS in the transplanted kidney in children is scarce. Since 1994 we have diagnosed RAS in seven children with the use of Doppler ultrasonography (US), confirming it with percutaneous angiography (PAG). In six of the seven patients percutaneous transluminal angioplasty (PTA) was performed. In one patient a metallic stent was placed due to the extension of the arterial lesion, and a second stent was placed in another child when a re-stenosis was diagnosed 1 month after the PTA. All patients presented with hypertension (de novo or 30% increase over previous values). After ruling out acute rejection, calcineurin inhibitor toxicity, and urinary obstruction, US was performed and, when an increase in arterial flux velocity was registered, PAG was also performed. Six children showed an increase in serum creatinine (Cr) and proteinuria. Blood pressure decreased after the procedure and Cr returned to previous levels in all children. One of the grafts was lost due to chronic transplant rejection 7 years later. The other children have a functioning kidney. Although this is a small group of patients, the consistently good results and the lack of reported experience prompted us to communicate our preliminary observation.
NASA Astrophysics Data System (ADS)
Li, Bo; Cheng, Jianli; Wang, Zhuanpei; Li, Yinchuan; Ni, Wei; Wang, Bin
2018-02-01
Flexible supercapacitors have attracted great interest due to outstanding flexibility and light weight. Poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) fibers have the great potential in using as electrodes for flexible supercapacitors due to the good flexibility. However, the reported conductivity and specific capacitance of these PEDOT: PSS fibers are not very high, which limit their electrochemical performances. In this work, composite fibers of reduced graphene oxide(rGO)-PEDOT: PSS with a highly-wrinkled structure on the surface and pores inside are prepared by wet spinning. The fibers with different ratios of graphene to PEDOT:PSS show a distinctly enhanced conductivity up to ca. 590 S·cm-1 and high strength up to ca. 18.4 MPa. Meanwhile, the composite fibers show an improved electrochemical performances, including a high specific areal capacitance of 131 mF cm-2 and high specific areal energy density of 4.55 μWh·cm-2. The flexible supercapacitors including fiber-shaped supercapacitors and interdigital designed supercapacitors not only could work in different bending states without obvious capacitance decay, but also have small leakage current. The interdigital design can further improve the performances of composite fibers with high capacitance and high utilization compared with traditional parallel connected structure.
Modelling the photochemical pollution over the metropolitan area of Porto Alegre, Brazil
NASA Astrophysics Data System (ADS)
Borrego, C.; Monteiro, A.; Ferreira, J.; Moraes, M. R.; Carvalho, A.; Ribeiro, I.; Miranda, A. I.; Moreira, D. M.
2010-01-01
The main purpose of this study is to evaluate the photochemical pollution over the Metropolitan Area of Porto Alegre (MAPA), Brazil, where high concentrations of ozone have been registered during the past years. Due to the restricted spatial coverage of the monitoring air quality network, a numerical modelling technique was selected and applied to this assessment exercise. Two different chemistry-transport models - CAMx and CALGRID - were applied for a summer period, driven by the MM5 meteorological model. The meteorological model performance was evaluated comparing its results to available monitoring data measured at the Porto Alegre airport. Validation results point out a good model performance. It was not possible to evaluate the chemistry models performance due to the lack of adequate monitoring data. Nevertheless, the model intercomparison between CAMx and CALGRID shows a similar behaviour in what concerns the simulation of nitrogen dioxide, but some discrepancies concerning ozone. Regarding the fulfilment of the Brazilian air quality targets, the simulated ozone concentrations surpass the legislated value in specific periods, mainly outside the urban area of Porto Alegre. The ozone formation is influenced by the emission of pollutants that act as precursors (like the nitrogen oxides emitted at Porto Alegre urban area and coming from a large refinery complex) and by the meteorological conditions.
NASA Astrophysics Data System (ADS)
Rahim, Ahmad Nabil Bin Ab; Mohamed, Faizal; Farid, Mohd Fairus Abdul; Fazli Zakaria, Mohd; Sangau Ligam, Alfred; Ramli, Nurhayati Binti
2018-01-01
Human factor can be affected by prevalence stress measured using Depression, Anxiety and Stress Scale (DASS). From the respondents feedback can be summarized that the main factor causes the highest prevalence stress is due to the working conditions that require operators to handle critical situation and make a prompt critical decisions. The relationship between the prevalence stress and performance shaping factors found that PSFFitness and PSFWork Process showed positive Pearson’s Correlation with the score of .763 and .826 while the level of significance, p = .028 and p = .012. These positive correlations with good significant values between prevalence stress and human performance shaping factor (PSF) related to fitness, work processes and procedures. The higher the stress level of the respondents, the higher the score of selected for the PSFs. This is due to the higher levels of stress lead to deteriorating physical health and cognitive also worsened. In addition, the lack of understanding in the work procedures can also be a factor that causes a growing stress. The higher these values will lead to the higher the probabilities of human error occur. Thus, monitoring the level of stress among operators RTP is important to ensure the safety of RTP.
Hepatic inflammatory pseudotumor: A case series
Calomeni, Guilherme D.; Ataíde, Elaine B.; Machado, Ricardo R.; Escanhoela, Cecília A.F.; Costa, Larissa B.E.; Boin, Ilka F.F.
2013-01-01
INTRODUCTION Inflammatory pseudotumor (IPT) is a rare lesion consisted of inflammatory and myofibroblastic cells. These lesions may be found in different organs. There are less than 300 described cases. PRESENTATION OF CASE Case 1. 64-year-old cirrhotic male with a palpable epigastric mass. CT showed a lesion in liver segments 2 and 3 and left hepatic artery aneurism. Percutaneous embolization and wide spectrum antibiotics were tried, however the lesion grew. Left lateral hepatectomy was performed, and HIPT diagnosed. The patient died due to multiple organ dysfunction. Case 2. 30-year-old male with abdominal pain and fever. CT showed a hepatic hilar lesion. Surgical resection was performed after an ineffectual antibiotic trial, and HIPT was confirmed. The patient is doing well. Case 3. 73-year-old female with abdominal pain and fever. CT showed a 7 cm lesion in the left liver lobe. Unrewarding cancerous screening was performed, and unsuccessful antibiotic course was tried. Resection was performed, and HIPT diagnosed. The patient is doing well. Case 4. 50-year-old cirrhotic male with abdominal pain. CT showed a segment 6 lesion and portal vein thrombosis. Considering cancer as the first hypothesis and the MELD score of 9, segmentectomy was performed. HIPT was the final diagnosis. The patient died due to abdominal sepsis. DISCUSSION HIPT is a lesion with a vast list of differential diagnosis. Antibiotics are the first line of therapy, although surgery is often necessary. Overall prognosis is good, although comorbidities may worsen it. CONCLUSION HIPT is a rare and misleading entity. PMID:23399515
Gallego-Delgado, María; Villacorta, Eduardo; Valenzuela-Vicente, M Carmen; Walias-Sánchez, Ángela; Ávila, Carmen; Velasco-Cañedo, M Jesús; Cano-Mozo, M Teresa; Martín-García, Agustín; García-Sánchez, María Jesús; Sánchez, Argelina; Cascón, Manuel; Sánchez, Pedro L
2018-05-21
The cardiology day hospital (CDH) is an alternative to hospitalization for scheduled cardiological procedures. The aims of this study were to analyze the activity, quality of care and the cost-effectiveness of a CDH. An observational descriptive study was conducted of the health care activity during the first year of operation of DHHA. The quality of care was analyzed through the substitution rate (outpatient procedures), cancellation rates, complications, and a satisfaction survey. For cost-effectiveness, we calculated the economic savings of avoided hospital stays. A total of 1646 patients were attended (mean age 69 ± 15 years, 60% men); 2550 procedures were scheduled with a cancellation rate of 4%. The most frequently cancelled procedure was electrical cardioversion. The substitution rate for scheduled invasive procedures was 66%. Only 1 patient required readmission after discharge from the CDH due to heart failure. Most surveyed patients (95%) considered the care received in the CDH to be good or very good. The saving due to outpatient-converted procedures made possible by the CDH was € 219 199.55, higher than the cost of the first year of operation. In our center, the CDH allowed more than two thirds of the invasive procedures to be performed on an outpatient basis, while maintaining the quality of care. In the first year of operation, the expenses due to its implementation were offset by a significant reduction in hospital admissions. Copyright © 2018 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.
A U.S. perspective on the adverse reactions from traditional Chinese medicines.
Ko, Richard J
2004-03-01
Traditional Chinese medicines (TCM) are popular in the United States and Asian and non-Asian consumers are using the product for disease treatment and health prevention. As more people are using TCM products, there are increased reports on adverse reactions. This review will focus on adverse reactions due to TCM as reported in the literature. The review is based on MedLine search of literatures using keywords including: herbs, herbal, traditional Chinese medicines with toxicity, adverse effects, death, drug interaction and pharmacokinetic. In addition, specific searches were performed using the above keywords with the common name and the scientific name of the plant product. The causes of adverse reactions associated with TCM are diverse. They include variability in active/toxic ingredients due to growing conditions, use of inherent toxic herbs causing toxicity, overdose of herbs, drug-herb interactions especially with pharmaceuticals that have narrow therapeutic index, coexisting diseases, and idiosyncratic reactions like allergy, hepatitis and anaphylaxis. Other adverse reactions can be due to manufacturing and quality problems causing adulteration, misidentification, substitution of one herb with another, variability in the amount of active ingredients, use of pharmaceuticals without identifying on the labels, improper processing and preparation, and contamination. To minimize the adverse reactions from TCM and protect the public, there must be adequate laws and regulations to ensure that products are manufactured with the highest standards. Manufacturers should be licensed by regulatory agency and manufactured under good manufacturing practice. TCM products must be evaluated for their safety before marketing. Proper labeling and good surveillance systems shall ensure the protection of the consumers.
Musicians' Ratings of Good versus Bad Vocal and String Performances.
ERIC Educational Resources Information Center
Geringer, John M.; Madsen, Clifford K.
1998-01-01
Continues a line of research attempting to ascertain the focus of musicians' attention when listening to music, particularly whether musicians demonstrate consistent listening patterns across excerpts designed to be perceived as good and bad performances. Indicates that musician-listeners consistently discriminated between good and bad…
Sun, Zhoumin; Fu, Haiying; Deng, Liu; Wang, Jianxiu
2013-01-25
In this paper, we fabricate a sensitive and stable amperometric UA amperometric biosensor using nanobiocomposite derived from thionine modified graphene oxide in this study. A simple wet-chemical strategy for synthesis of thionine-graphene oxide hybrid nanosheets (T-GOs) through π-π stacking has been demonstrated. Various techniques, such as UV-vis absorption spectroscopy, X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), atomic force microscopy (AFM) and electrochemistry have been utilized to characterize the formation of the T-GOs. Due to the synergistic effect between thionine and graphene oxide, the nanosheets exhibited excellent performance toward H(2)O(2) reduction. The incorporation of thionine onto graphene oxide surface resulted in more than a twice increase in the amperometric response to H(2)O(2) of the thionine modified electrode. The as-formed T-GOs also served as a biocompatible matrix for enzyme assembly and a mediator to facilitate the electron transfer between the enzyme and the electrode. Using UOx as a model system, we have developed a simple and effective sensing platform for assay of uric acid at physiological levels. UA has been successfully detected at -0.1 V without any interference due to other electroactive compounds at physiological levels of glucose (5 mM), ascorbic acid (0.1 mM), noradrenalin (0.1 mM), and dopamine (0.1 mM). The response displays a good linear range from 0.02 to 4.5 mM with detection limit 7 μM. The application of this modified electrode in blood and urine UA exhibited a good performance. The robust and advanced hybrid materials might hold great promise in biosensing, energy conversion, and biomedical and electronic systems. Copyright © 2012 Elsevier B.V. All rights reserved.
NASA Astrophysics Data System (ADS)
Jahangir, M. M. R.; Richards, K. G.; Healy, M. G.; Gill, L.; Müller, C.; Johnston, P.; Fenton, O.
2016-01-01
The removal efficiency of carbon (C) and nitrogen (N) in constructed wetlands (CWs) is very inconsistent and frequently does not reveal whether the removal processes are due to physical attenuation or whether the different species have been transformed to other reactive forms. Previous research on nutrient removal in CWs did not consider the dynamics of pollution swapping (the increase of one pollutant as a result of a measure introduced to reduce a different pollutant) driven by transformational processes within and around the system. This paper aims to address this knowledge gap by reviewing the biogeochemical dynamics and fate of C and N in CWs and their potential impact on the environment, and by presenting novel ways in which these knowledge gaps may be eliminated. Nutrient removal in CWs varies with the type of CW, vegetation, climate, season, geographical region, and management practices. Horizontal flow CWs tend to have good nitrate (NO3-) removal, as they provide good conditions for denitrification, but cannot remove ammonium (NH4+) due to limited ability to nitrify NH4+. Vertical flow CWs have good NH4+ removal, but their denitrification ability is low. Surface flow CWs decrease nitrous oxide (N2O) emissions but increase methane (CH4) emissions; subsurface flow CWs increase N2O and carbon dioxide (CO2) emissions, but decrease CH4 emissions. Mixed species of vegetation perform better than monocultures in increasing C and N removal and decreasing greenhouse gas (GHG) emissions, but empirical evidence is still scarce. Lower hydraulic loadings with higher hydraulic retention times enhance nutrient removal, but more empirical evidence is required to determine an optimum design. A conceptual model highlighting the current state of knowledge is presented and experimental work that should be undertaken to address knowledge gaps across CWs, vegetation and wastewater types, hydraulic loading rates and regimes, and retention times, is suggested. We recommend that further research on process-based C and N removal and on the balancing of end products into reactive and benign forms is critical to the assessment of the environmental performance of CWs.
20 CFR 404.454 - Good cause for failure to make required reports.
Code of Federal Regulations, 2013 CFR
2013-04-01
... timely report under the provisions described in §§ 404.450 and 404.452 will not result in a penalty... timely report was due to good cause. Before making any penalty determination as described in §§ 404.451 and 404.453, the individual shall be advised of the penalty and good cause provisions and afforded an...
20 CFR 404.454 - Good cause for failure to make required reports.
Code of Federal Regulations, 2014 CFR
2014-04-01
... timely report under the provisions described in §§ 404.450 and 404.452 will not result in a penalty... timely report was due to good cause. Before making any penalty determination as described in §§ 404.451 and 404.453, the individual shall be advised of the penalty and good cause provisions and afforded an...
20 CFR 404.454 - Good cause for failure to make required reports.
Code of Federal Regulations, 2012 CFR
2012-04-01
... timely report under the provisions described in §§ 404.450 and 404.452 will not result in a penalty... timely report was due to good cause. Before making any penalty determination as described in §§ 404.451 and 404.453, the individual shall be advised of the penalty and good cause provisions and afforded an...
20 CFR 404.454 - Good cause for failure to make required reports.
Code of Federal Regulations, 2011 CFR
2011-04-01
... timely report under the provisions described in §§ 404.450 and 404.452 will not result in a penalty... timely report was due to good cause. Before making any penalty determination as described in §§ 404.451 and 404.453, the individual shall be advised of the penalty and good cause provisions and afforded an...
20 CFR 404.454 - Good cause for failure to make required reports.
Code of Federal Regulations, 2010 CFR
2010-04-01
... timely report under the provisions described in §§ 404.450 and 404.452 will not result in a penalty... timely report was due to good cause. Before making any penalty determination as described in §§ 404.451 and 404.453, the individual shall be advised of the penalty and good cause provisions and afforded an...
NASA Astrophysics Data System (ADS)
Mustapa, S. A. S.; Ramli Sulong, N. H.
2017-06-01
This research deals with contribution of hybrid fillers with palm oil clinker (POC) as a novel bio-filler in solvent-borne intumescent fire protective coating for steel. The hybrid fillers with POC were mixed in appropriate amount of additives and acrylic binder to produce the intumescent coatings. The intumescent coatings were characterized by using Bunsen burner test, surface spread of flame, thermogravimetric analysis, field emission scanning electron microscopy, static immersion and Instron micro tester equipment. Specimen with POC as a single filler has significantly enhanced the fire protection performances of the intumescent coating due to the high thermal stability of POC, where less than 10% of temperature different when compared to specimens with hybrid fillers. From the flame spread classification, class 1 is the best classification while Class 4 is the worst and considered high risk. All specimens was classified as class 1 since the final spread of flame was less than 165 mm. For hybrid fillers composition, specimen consist of POC/Al(OH)3/TiO2 has significantly improved the water resistance of the coating due to the low solubility of Al(OH)3 in water, while specimen contain of Mg(OH)2 had higher mechanical strength due to the strong bonding between the metal surface and acrylic binder/Mg(OH)2 filler. It was found that coating with the incorporation of all hybrid fillers gives excellent fire protection performance with good thermal stability, water resistance and mechanical properties. It can be concluded that, the selection of appropriate composition of fillers and binder in intumescent coating was highly influence the intumescent coating performance.
Broad-band BOS (BBYB) development and calibration in Taiwan
NASA Astrophysics Data System (ADS)
Lin, C. R.; Wang, C. C.; Kuo, B. Y.; Chen, P.; Jang, J. P.; Chang, H.; Laio, Y. C.; Chang, K. H.; Lin, F. S.
2016-12-01
Since 2009, combine with Academia Sinica, National Applied Research Laboratories and National Sun Yat-sen University formed ocean bottom seismograph (OBS) development team to develop sub-broadband OBS (called Yardbird OBS). Through a series deploy experiment at seafloor offshore Taiwan that got a lot of data can be used to study plate tectonics, seismic activity, source characteristics. Nowadays they have pretty good results already. Due to bandwidth limitations of the Yardbird OBS that inadequate to use for analyze global-scale earthquake. Therefor developing broadband ocean bottom seismograph is an important goal for the development team. Currently the broadband OBS (called BBYB) design and construction have completed the initial experiment phase. Due to underwater instruments always got high risk. Something accidentally making equipment sank in the sea cannot be recovery. Even recovery of equipment may also be causing poor performance because there is no data record. It cannot be to accomplish the experiment mission. In order to improve the OBS performance, avoid OBS dis-recovery or data collection is incomplete, must be sure all OBS's each component (such as seismic data recording device, balanced body, sonar dashboard, instruments and internal wiring ...) with well-done quality before assembly. Each component could go through very rigorous testing, strict and pick out the good components in the assembly process. Be sure all of produce the OBS under the water after a long deployment could successful recovery and got valuable data. In this presentation we will show a serial testing procedure and results for quality each BBYB component. Such as: Data logger: digitizer sensitivity, sampling rate, clock timing. Acoustic controller: function of Enable, Disable, Range, Release 1, Release 2, Option 1(Release disable). Air pressure gauge for glass ball: accuracy. A check lists of connector wiring check for assembling instrument. Design deploy and recovery procedure for operation on deck. We hope through repeated testing to ensure perfect performance of BBYB and apply the testing concept to another equipment for improve instruments performance. Keywords: ocean bottom seismograph (OBS); Data logger; Acoustic controller; Air pressure gauge.
Is the 'Cox effect' good for us?
NASA Astrophysics Data System (ADS)
Mellor, Felicity
2012-10-01
Some claim that recent increases in the number of students studying physics in the UK are due to the TV appearances of physicist Brian Cox. But as Felicity Mellor warns, the "Cox effect" may not be all good news.
Thermal stability and adhesion of low-emissivity electroplated Au coatings.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Jorenby, Jeff W.; Hachman, John T., Jr.; Yang, Nancy Y. C.
We are developing a low-emissivity thermal management coating system to minimize radiative heat losses under a high-vacuum environment. Good adhesion, low outgassing, and good thermal stability of the coating material are essential elements for a long-life, reliable thermal management device. The system of electroplated Au coating on the adhesion-enhancing Wood's Ni strike and 304L substrate was selected due to its low emissivity and low surface chemical reactivity. The physical and chemical properties, interface bonding, thermal aging, and compatibility of the above Au/Ni/304L system were examined extensively. The study shows that the as-plated electroplated Au and Ni samples contain submicron columnarmore » grains, stringers of nanopores, and/or H{sub 2} gas bubbles, as expected. The grain structure of Au and Ni are thermally stable up to 250 C for 63 days. The interface bonding is strong, which can be attributed to good mechanical locking among the Au, the 304L, and the porous Ni strike. However, thermal instability of the nanopore structure (i.e., pore coalescence and coarsening due to vacancy and/or entrapped gaseous phase diffusion) and Ni diffusion were observed. In addition, the study also found that prebaking 304L in the furnace at {ge} 1 x 10{sup -4} Torr promotes surface Cr-oxides on the 304L surface, which reduces the effectiveness of the intended H-removal. The extent of the pore coalescence and coarsening and their effect on the long-term system integrity and outgassing are yet to be understood. Mitigating system outgassing and improving Au adhesion require a further understanding of the process-structure-system performance relationships within the electroplated Au/Ni/304L system.« less
NASA Astrophysics Data System (ADS)
Quéno, Louis; Vionnet, Vincent; Cabot, Frédéric; Vrécourt, Dominique; Dombrowski-Etchevers, Ingrid
2017-04-01
In the Pyrenees, freezing precipitations in altitude occur at least once per winter, leading to the formation of a pure ice layer on the surface of the snowpack. It may lead to accidents and fatalities among mountaineers and skiers, with sometimes a higher human toll than avalanches. Such events are not predicted by the current operational systems for snow and avalanche hazard forecasting. A crowd-sourced database of surface ice layer occurrences is first built up, using reports from Internet mountaineering and ski-touring communities, to mitigate the lack of observations from conventional observation networks. A simple diagnostic of freezing precipitation is then developed, based on the cloud water content and screen temperature forecast by the Numerical Weather Prediction model AROME, operating at 2.5-km resolution. The performance of this diagnostic is assessed for the event of 5-6 January 2012, with a good representation of altitudinal and spatial distributions of the ice layer. An evaluation of the diagnostic for major events over five winters gives good skills of detection compared to the occurrences reported in the observation database. A new modelling of ice formation on the surface of the snowpack due to impinging supercooled water is added to the detailed snowpack model Crocus. It is combined to the atmospheric diagnostic of freezing precipitations and resulting snowpack simulations over a winter season capture well the formation of the main ice layers. Their influence on the snowpack stratigraphy is also realistically simulated. These simple methods enable to forecast the occurrence of surface ice layer formations with good confidence and to simulate their evolution within the snowpack, even if an accurate estimation of freezing precipitation amounts remains the main challenge.
48 CFR 1816.405-275 - Award fee evaluation scoring.
Code of Federal Regulations, 2010 CFR
2010-10-01
...; exemplary performance in a timely, efficient, and economical manner; very minor (if any) deficiencies with no adverse effect on overall performance. (2) Very good (90-81): Very effective performance, fully... economical manner for the most part; only minor deficiencies. (3) Good (80-71): Effective performance; fully...
Performance testing of asphalt concrete containing crumb rubber modifier and warm mix additives
NASA Astrophysics Data System (ADS)
Ikpugha, Omo John
Utilisation of scrap tire has been achieved through the production of crumb rubber modified binders and rubberised asphalt concrete. Terminal and field blended asphalt rubbers have been developed through the wet process to incorporate crumb rubber into the asphalt binder. Warm mix asphalt technologies have been developed to curb the problem associated with the processing and production of such crumb rubber modified binders. Also the lowered production and compaction temperatures associated with warm mix additives suggests the possibility of moisture retention in the mix, which can lead to moisture damage. Conventional moisture sensitivity tests have not effectively discriminated good and poor mixes, due to the difficulty of simulating field moisture damage mechanisms. This study was carried out to investigate performance properties of crumb rubber modified asphalt concrete, using commercial warm mix asphalt technology. Commonly utilised asphalt mixtures in North America such as dense graded and stone mastic asphalt were used in this study. Uniaxial Cyclic Compression Testing (UCCT) was used to measure permanent deformation at high temperatures. Indirect Tensile Testing (IDT) was used to investigate low temperature performance. Moisture Induced Sensitivity Testing (MiST) was proposed to be an effective method for detecting the susceptibility of asphalt mixtures to moisture damage, as it incorporates major field stripping mechanisms. Sonnewarm(TM), Sasobit(TM) and Evotherm(TM) additives improved the resistance to permanent deformation of dense graded mixes at a loading rate of 0.5 percent by weight of the binder. Polymer modified mixtures showed superior resistance to permanent deformation compared to asphalt rubber in all mix types. Rediset(TM) WMX improves low temperature properties of dense graded mixes at 0.5 percent loading on the asphalt cement. Rediset LQ and Rediset WMX showed good anti stripping properties at 0.5 percent loading on the asphalt cement. The American Association of State Highway and Transportation Official's Mechanistic-Empirical Pavement Design Guide (AASHTO MEPDG) software was used to predict long term low temperature performance of the mixtures in various areas of Ontario. Sasobit, Rediset LQ and Rediset WMX gave good 15 years prediction with stone mastic asphalt mixtures but the performance of dense graded mixtures was less satisfactory.
NASA Astrophysics Data System (ADS)
D' Amora, Marta; Rodio, Marina; Bartelmess, Juergen; Sancataldo, Giuseppe; Brescia, Rosaria; Cella Zanacchi, Francesca; Diaspro, Alberto; Giordani, Silvia
2016-09-01
Functionalized carbon nano-onions (f-CNOs) are of great interest as platforms for imaging, diagnostic and therapeutic applications due to their high cellular uptake and low cytotoxicity. To date, the toxicological effects of f-CNOs on vertebrates have not been reported. In this study, the possible biological impact of f-CNOs on zebrafish during development is investigated, evaluating different toxicity end-points such as the survival rate, hatching rate, and heart beat rate. Furthermore, a bio-distribution study of boron dipyrromethene (BODIPY) functionalized CNOs in zebrafish larvae is performed by utilizing inverted selective plane illumination microscopy (iSPIM), due to its intrinsic capability of allowing for fast 3D imaging. Our in vivo findings indicate that f-CNOs exhibit no toxicity, good biocompatibility (in the concentration range of 5-100 μg mL-1) and a homogenous biodistribution in zebrafish larvae.
[Primary hyperaldosteronism due to unilateral adrenal hyperplasia with surgical resolution].
Rubio-Puchol, O; Garzón-Pastor, S; Salom-Vendrell, C; Hernández-Mijares, A
Unilateral adrenal hyperplasia is a rare cause of primary hyperaldosteronism (around a 3%) that has surgical treatment. A case of a patient with hypertension resistant to conventional therapy in treatment with 7 drugs who presented with primary hyperaldosteronism due to unilateral adrenal hyperplasia is presented. A left adrenalectomy was performed, and the patient had a good clinical response, with no need of any drug after 2 years of surgery. Unilateral adrenal hyperplasia is a different entity and it is not an asymmetric variant of the bilateral adrenal hyperplasia. In the study of patients with primary hyperaldosteronism and imaging tests with absence of adenoma is a diagnosis that must be considered before cataloguing patients with bilateral adrenal hyperplasia and start a medical treatment, because unilateral adrenal hyperplasia would have a surgical resolution. Copyright © 2016 SEH-LELHA. Publicado por Elsevier España, S.L.U. All rights reserved.
Severe bioprosthetic mitral valve stenosis in pregnancy.
Munoz-Mendoza, Jerson; Pinto Miranda, Veronica; Tanawuttiwat, Tanyanan; Badiye, Amit; Chaparro, Sandra V
2016-01-01
A 21-year-old woman in the 16th week of pregnancy was admitted due to acute presentation of severe exertional dyspnea. She had undergone mitral valve replacement (MVR) with bioprosthetic valve for infective endocarditis 2 years ago. She developed congestive heart failure from mitral bioprosthetic valve stenosis due to early structural valve deterioration. She also had severe pulmonary hypertension and underwent a redo MVR using a mechanical valve prosthesis with good maternal outcome but fetal demise. This report brings up the debate about what type of valve should be used in women in reproductive age, and discusses the management of severe mitral stenosis and stenosis of a bioprosthetic valve during pregnancy. Surgical options can almost always be delayed until fetal maturity is achieved and a simultaneous cesarean section can be performed. However, under certain circumstances when the maternal welfare is in jeopardy the surgical intervention is mandatory even before the fetus reaches viability.
[Isolated lung transplantation--evaluation of patients and initial results].
Speich, R; Böhler, A; Zollinger, A; Stocker, R; Vogt, P; Carrel, T; Lang, T; Schmid, R; Stöhr, S; Vogt, P R
1995-04-22
Between November 1992 and May 1994 we performed 10 single and 5 double lung transplants in patients with end-stage lung diseases due to lymphangioleiomyomatosis (4), cystic fibrosis (3), pulmonary hypertension (3), pulmonary fibrosis (3) and chronic obstructive lung disease (2). In the 13 patients (87%) surviving for median 245 (19-567) days, FEV1 improved from median 640 ml to 1410 ml and the 12-minute walk distance from median 315 to 1100 meters. 10 patients (77%) enjoy a good or even excellent quality of life. 2 patients died 11 and 62 days postoperatively, due to multi-organ failure and invasive pulmonary aspergillosis respectively. The main postoperative problems are fungal and cytomegalovirus infections and chronic rejection in the form of bronchiolitis obliterans. In Switzerland as elsewhere, lung transplantation has become an established modality for the management of end-stage diseases of the lung and pulmonary circulation.
Evaluating and Optimizing Online Advertising: Forget the Click, but There Are Good Proxies.
Dalessandro, Brian; Hook, Rod; Perlich, Claudia; Provost, Foster
2015-06-01
Online systems promise to improve advertisement targeting via the massive and detailed data available. However, there often is too few data on exactly the outcome of interest, such as purchases, for accurate campaign evaluation and optimization (due to low conversion rates, cold start periods, lack of instrumentation of offline purchases, and long purchase cycles). This paper presents a detailed treatment of proxy modeling, which is based on the identification of a suitable alternative (proxy) target variable when data on the true objective is in short supply (or even completely nonexistent). The paper has a two-fold contribution. First, the potential of proxy modeling is demonstrated clearly, based on a massive-scale experiment across 58 real online advertising campaigns. Second, we assess the value of different specific proxies for evaluating and optimizing online display advertising, showing striking results. The results include bad news and good news. The most commonly cited and used proxy is a click on an ad. The bad news is that across a large number of campaigns, clicks are not good proxies for evaluation or for optimization: clickers do not resemble buyers. The good news is that an alternative sort of proxy performs remarkably well: observed visits to the brand's website. Specifically, predictive models built based on brand site visits-which are much more common than purchases-do a remarkably good job of predicting which browsers will make a purchase. The practical bottom line: evaluating and optimizing campaigns using clicks seems wrongheaded; however, there is an easy and attractive alternative-use a well-chosen site-visit proxy instead.
NASA Astrophysics Data System (ADS)
Ljungberg, Sven-Ake
1995-03-01
Different building constructions and craftsmanship give rise to different thermal performance and damage conditions. The building stock of most industrial countries consists of buildings of various age, and constructions, from old historic buildings with heavy stone or wooden construction, to new buildings with heavy or light concrete construction, or modern steel or wooden construction. In this paper the result from a detailed infrared survey of 50 buildings from six Swedish military camps is presented. The presentation is limited to a comparison of thermal performance and damage conditions of buildings of various ages, functions, and constructions, of a building period of more than 100 years. The result is expected to be relevant even to civilian buildings. Infrared surveys were performed during 1992-1993, with airborne, and mobile short- and longwave infrared systems, out- and indoor thermography. Interpretation and analysis of infrared data was performed with interactive image and analyzing systems. Field inspections were carried out with fiber optics system, and by ocular inspections. Air-exchange rate was measured in order to quantify air leakages through the building envelope, indicated in thermograms. The objects studied were single-family houses, barracks, office-, service-, school- and exercise buildings, military hotels and restaurants, aircraft hangars, and ship factory buildings. The main conclusions from this study are that most buildings from 1880 - 1940 have a solid construction with a high quality of craftsmanship, relatively good thermal performance, due to extremely thick walls, and adding insulation at the attic floor. From about 1940 - 1960 the quality of construction, thermal performance and craftsmanship seem to vary a lot. Buildings constructed during the period of 1960 - 1990 have in general the best thermal performance due to a better insulation capacity, however, also one finds here the greatest variety of problems. The result from this study is to be incorporated in planning of short- and long term maintenance programs of the Swedish Defence. In general the military buildings are expected to have better status than civilian buildings, due to the more rigorous control during the building process, performed by military building authorities.
Liquid crystal polyester-carbon fiber composites
NASA Technical Reports Server (NTRS)
Chung, T. S.
1984-01-01
Liquid crystal polymers (LCP) have been developed as a thermoplastic matrix for high performance composites. A successful melt impregnation method has been developed which results in the production of continuous carbon fiber (CF) reinforced LCP prepreg tape. Subsequent layup and molding of prepreg into laminates has yielded composites of good quality. Tensile and flexural properties of LCP/CF composites are comparable to those of epoxy/CF composites. The LCP/CF composites have better impact resistance than the latter, although epoxy/CF composites possess superior compression and shear strength. The LCP/CF composites have good property retention until 200 F (67 % of room temperature value). Above 200 F, mechanical properties decrease significantly. Experimental results indicate that the poor compression and shear strength may be due to the poor interfacial adhesion between the matrix and carbon fiber as adequate toughness of the LCP matrix. Low mechanical property retention at high temperatures may be attributable to the low beta-transition temperature (around 80 C) of the LCP matrix material.
[Current alternatives in the surgical treatment of chronic pancreatitis--a review article].
Kat'uchová, Jana; Radonak, Jozef
2011-01-01
Chronic pancreatitis is characterized as an inflammatory process affecting the pancreas that causes progressive destruction of the gland and fibrosis, with subsequent endocrine and exocrine insufficiency. The most common cause of chronic pancreatitis is alcohol use in combination with nicotine. Manifestations are persistent or recurrent painful attacks. The only parameter of successful treatment of chronic pancreatitis is a relieve from long-lasting pain and improvement of the quality of life. Surgical treatment options include drainage operations on the pancreas, pancreatic resection or a combination of both. With optimal surgical treatment performed and good patient's compliance, operations for chronic pancreatitis have low number of post-operative complications and relatively good long-term results. The continued consumption of alcohol and drugs bring about worse outcomes, sometimes even a complete failure of therapy. Chronic pancreatitis also has considerable socio-economic consequences. Due to the persisting pain and frequent hospitalization it can lead to long-term disability and early retirement predominantly in young patients.
[External rhinoplasty: a useful approach for a young plastic surgeon].
Adant, J P; Bluth, F; Fissette, J
1998-12-01
Among the frequently performed plastic surgery operations, rhinoplasty is the most difficult to obtain consistently good results. It is very challenging for young plastic surgeons to modify the external appearance of the nose and restore or maintain a good airway. The external approach has alleviated some of the problems due to understanding and learning of the rhinoplasty operation. Actually, open rhinoplasty allows better visualization of anatomical deformities and better manipulation of tissues allowing better integration of nasal anatomy and physiology. This paper reviews a personal series of 82 patients operated via an open approach between October 94 and October 97. During the same period, 24 patients were operated via an endonasal or percutaneous approach (osteotomies). Indications, advantages and disadvantages of the open approach are discussed. The various techniques used in this series are described and then critically analyzed. In open rhinoplasty, our present revision rate is 8.5%. In conclusion, the open approach seems to be useful for young rhinoplastic surgeons.
Computational Modelling of Patella Femoral Kinematics During Gait Cycle and Experimental Validation
NASA Astrophysics Data System (ADS)
Maiti, Raman
2016-06-01
The effect of loading and boundary conditions on patellar mechanics is significant due to the complications arising in patella femoral joints during total knee replacements. To understand the patellar mechanics with respect to loading and motion, a computational model representing the patella femoral joint was developed and validated against experimental results. The computational model was created in IDEAS NX and simulated in MSC ADAMS/VIEW software. The results obtained in the form of internal external rotations and anterior posterior displacements for a new and experimentally simulated specimen for patella femoral joint under standard gait condition were compared with experimental measurements performed on the Leeds ProSim knee simulator. A good overall agreement between the computational prediction and the experimental data was obtained for patella femoral kinematics. Good agreement between the model and the past studies was observed when the ligament load was removed and the medial lateral displacement was constrained. The model is sensitive to ±5 % change in kinematics, frictional, force and stiffness coefficients and insensitive to time step.
Tramadol Extended-Release for the Management of Pain due to Osteoarthritis
Guetti, Cristiana; Paladini, Antonella; Varrassi, Giustino
2013-01-01
Current knowledge on pathogenesis of osteoarticular pain, as well as the consequent several, especially on the gastrointestinal, renal, and cardiovascular systems, side effects of NSAIDs, makes it difficult to perform an optimal management of this mixed typology of pain. This is especially observable in elderly patients, the most frequently affected by osteoarthritis (OA). Tramadol is an analgesic drug, the action of which has a twofold action. It has a weak affinity to mu opioid receptors and, at the same time, can result in inhibition of the reuptake of noradrenaline and serotonin in nociceptorial descending inhibitory control system. These two mechanisms, “opioidergic” and “nonopioidergic,” are the grounds for contrasting certain types of pain that are generally less responsive to opioids, such as neuropathic pain or mixed OA pain. The extended-release formulation of tramadol has good efficacy and tolerability and acts through a dosing schedule that allows a high level of patients compliance to therapies with a good recovery outcome for the patients' functional status. PMID:27335872
Mao, Hui; Liang, Jiachen; Zhang, Haifeng; Pei, Qi; Liu, Daliang; Wu, Shuyao; Zhang, Yu; Song, Xi-Ming
2015-08-15
Novel poly(ionic liquids) functionalized polypyrrole/graphene oxide nanosheets (PILs/PPy/GO) were prepared by the polymerization of 1-vinyl-3-ethylimidazole bromide (VEIB) on the surface of N-vinyl imidazolium modified PPy/GO nanosheets. Due to the synergistic effects of GO with well-defined lamellar structures, conductive PPy and biocompatible PILs, PILs/PPy/GO modified glassy carbon electrode (GCE) presented the excellent electrochemical catalytic activity towards dopamine (DA) with good stability, high sensitivity and wide linear range in the present of ascorbic acid (AA) with high concentration. PILs played an essential role for the simultaneous determination of DA and AA in a mixture, whose existence effectively improved the transmission mode of electrons and resulted in the different electrocatalytic performance towards the oxidation of DA and AA. It is indicated that PILs/PPy/GO nanosheets can act as a good steady and sensitive electrode material for the development of improved DA sensors. Copyright © 2015 Elsevier B.V. All rights reserved.
Nanostructured mesoporous silica: new perspectives for fighting antimicrobial resistance
NASA Astrophysics Data System (ADS)
Voicu, Georgeta; Dogaru, Ionuţ; Meliţă, Daniela; Meştercă, Raluca; Spirescu, Vera; Stan, Eliza; Tote, Eliza; Mogoantă, Laurenţiu; Mogoşanu, George Dan; Grumezescu, Alexandru Mihai; Truşcă, Roxana; Vasile, Eugeniu; Iordache, Florin; Chifiriuc, Mariana-Carmen; Holban, Alina Maria
2015-05-01
This paper investigates the antimicrobial potential of nanostructured mesoporous silica (NMS) functionalized with essential oils (EOs) and antibiotics (ATBs). The NMS networks were obtained by the basic procedure from cetyltrimethylammonium bromide and tetraethyl orthosilicate in the form of granules with diameters ranging from 100 to 300 nm with an average pore diameter of 2.2 nm, as confirmed by the BET-TEM analyses. The Salvia officinalis (SO) and Coriandrum sativum (CS) EOs and the streptomycin and neomycin ATBs were loaded in the NMS pores. TG analysis was performed in order to estimate the amount of the entrapped volatile EOs. The results of the biological analyses revealed that NMS/SO and NMS/CS exhibited a very good antimicrobial activity to an extent comparable or even superior to the one triggered by ATB, and a good in vitro and in vivo biocompatibility. Due to their regular pores, high biocompatibility, antimicrobial activity, and capacity to stabilize the volatile EOs, the obtained NMS can be used as an efficient drug delivery system for further biomedical applications.
Computational Modelling of Patella Femoral Kinematics During Gait Cycle and Experimental Validation
NASA Astrophysics Data System (ADS)
Maiti, Raman
2018-06-01
The effect of loading and boundary conditions on patellar mechanics is significant due to the complications arising in patella femoral joints during total knee replacements. To understand the patellar mechanics with respect to loading and motion, a computational model representing the patella femoral joint was developed and validated against experimental results. The computational model was created in IDEAS NX and simulated in MSC ADAMS/VIEW software. The results obtained in the form of internal external rotations and anterior posterior displacements for a new and experimentally simulated specimen for patella femoral joint under standard gait condition were compared with experimental measurements performed on the Leeds ProSim knee simulator. A good overall agreement between the computational prediction and the experimental data was obtained for patella femoral kinematics. Good agreement between the model and the past studies was observed when the ligament load was removed and the medial lateral displacement was constrained. The model is sensitive to ±5 % change in kinematics, frictional, force and stiffness coefficients and insensitive to time step.
Zhang, Weidong; Li, Guoping; Xu, Letian; Zhuo, Yue; Wan, Wenming; Yan, Ni; He, Gang
2018-05-21
The introduction of main group elements into conjugated scaffolds is emerging as a key route to novel optoelectronic materials. Herein, an efficient and versatile way to synthesize polymerizable 9,10-azaboraphenanthrene ( BNP )-containing monomers by aromaticity-driven ring expansion reactions between highly antiaromatic borafluorene and azides is reported, and the corresponding conjugated small molecules and polymers are developed as well. The BNP -containing small molecules and conjugated polymers showed good air/moisture stability and notable fluorescence properties. Addition of fluoride ions to the BNP -based small molecules and polymers induced a rapid change in the emission color from blue to green/yellow, respectively, accompanied by strong intensity changes. The conjugated polymers showed better ratiometric sensing performance than small molecules due to the exciton migration along the conjugated chains. Further experiments showed that the sensing process is fully reversible. The films prepared by solution-deposition of BNP -based compounds in the presence of polycaprolactone also showed good ratiometric sensing for fluoride ions.
Sulfur-based autotrophic denitrification from the micro-polluted water.
Zhou, Weili; Liu, Xu; Dong, Xiaojing; Wang, Zheng; Yuan, Ying; Wang, Hui; He, Shengbing
2016-06-01
Eutrophication caused by high concentrations of nutrients is a huge problem for many natural lakes and reservoirs. Removing the nitrogen contamination from the low C/N water body has become an urgent need. Autotrophic denitrification with the sulfur compound as electron donor was investigated in the biofilter reactors. Through the lab-scale experiment, it was found that different sulfur compounds and different carriers caused very different treatment performances. Thiosulfate was selected to be the best electron donor and ceramsite was chosen as the suitable carrier due to the good denitrification efficiency, low cost and the good resistibility against the high hydraulic loads. Later the optimum running parameters of the process were determined. Then the pilot-scale experiment was carried out with the real micro-polluted water from the West Lake, China. The results indicated that the autotrophic denitrification with thiosulfate as electron donor was feasible and applicable for the micro-polluted lake water. Copyright © 2016. Published by Elsevier B.V.
NASA Astrophysics Data System (ADS)
Nelea, Valentin D.; Ristoscu, Carmen; Colis, Silviu; Arens, Simona; Pelletier, Herve; Mihailescu, Ion N.; Mille, Pierre
2001-04-01
Crystalline hydroxyapatite (HA) thin films grown on metallic substrates is the best choice for bone restoration. This is due to the good biological compatibility of the hydroxyapatite material combined with the good mechanical characteristics of the substrates. We deposit HA thin films by Pulsed Laser Deposition (PLD) in vacuum at room temperature using a KrF* excimer laser ((lambda) equals 248 nm, (tau) FWHM >= 20 ns). The depositions were performed directly on Ti-5Al-2.5Fe or on substrates previously coated with a TiN buffer layer. The HA deposited structures were characterized by complementary techniques: GIXRD, SEM, TEM, SAED, EDS and nanoindentation. Properties of the HA films grown with and without the TiN buffer were discussed in term of microstructure and mechanical behavior. The films with interlayer preserve the stoichiometry, are completely recrystallized and present better mechanical characteristics as compared with those without buffer.
Kim, Seong-Hoon; Ryu, Hye Guk; Lee, Juhyun; Shin, Joon; Harikishore, Amaravadhi; Jung, Hoe-Yune; Jung, Hoe-Youn; Kim, Ye Seul; Lyu, Ha-Na; Oh, Eunji; Baek, Nam-In; Choi, Kwan-Yong; Yoon, Ho Sup; Kim, Kyong-Tai
2015-09-28
Many mitotic kinases have been targeted for the development of anti-cancer drugs, and inhibitors of these kinases have been expected to perform well for cancer therapy. Efforts focused on selecting good targets and finding specific drugs to target are especially needed, largely due to the increased frequency of anti-cancer drugs used in the treatment of lung cancer. Vaccinia-related kinase 1 (VRK1) is a master regulator in lung adenocarcinoma and is considered a key molecule in the adaptive pathway, which mainly controls cell survival. We found that ursolic acid (UA) inhibits the catalytic activity of VRK1 via direct binding to the catalytic domain of VRK1. UA weakens surveillance mechanisms by blocking 53BP1 foci formation induced by VRK1 in lung cancer cells, and possesses synergistic anti-cancer effects with DNA damaging drugs. Taken together, UA can be a good anti-cancer agent for targeted therapy or combination therapy with DNA damaging drugs for lung cancer patients.
Liu, Pei; Zhu, Yisi; Lee, Seung Hee; Yun, Minhee
2016-12-01
In this work, we report a flexible field-effect-transistor (FET) biosensor design based on two-dimensional (2-D) polyaniline (PANI) nanostructure. The flexible biosensor devices were fabricated through a facile and inexpensive method that combines top-down and bottom-up processes. The chemically synthesized PANI nanostructure showed excellent p-type semiconductor properties as well as good compatibility with flexible design. With the 2-D PANI nanostructure being as thin as 80 nm and its extremely large surface-area-to-volume (SA/V) ratio due to the intrinsic properties of PANI chemical synthesis, the developed flexible biosensor exhibited outstanding sensing performance in detecting B-type natriuretic peptide (BNP) biomarkers, and was able to achieve high specificity (averagely 112 folds) with the limit of detection as low as 100 pg/mL. PANI nanostructure under bending condition was also investigated and showed controllable conductance changes being less than 20% with good restorability which may open up the possibility for wearable applications.
Tri-state delta modulation system for Space Shuttle digital TV downlink
NASA Technical Reports Server (NTRS)
Udalov, S.; Huth, G. K.; Roberts, D.; Batson, B. H.
1981-01-01
Future requirements for Shuttle Orbiter downlink communication may include transmission of digital video which, in addition to black and white, may also be either field-sequential or NTSC color format. The use of digitized video could provide for picture privacy at the expense of additional onboard hardware, together with an increased bandwidth due to the digitization process. A general objective for the Space Shuttle application is to develop a digitization technique that is compatible with data rates in the 20-30 Mbps range but still provides good quality pictures. This paper describes a tri-state delta modulation/demodulation (TSDM) technique which is a good compromise between implementation complexity and performance. The unique feature of TSDM is that it provides for efficient run-length encoding of constant-intensity segments of a TV picture. Axiomatix has developed a hardware implementation of a high-speed TSDM transmitter and receiver for black-and-white TV and field-sequential color. The hardware complexity of this TSDM implementation is summarized in the paper.
High-performance silicon nanowire field-effect transistor with silicided contacts
NASA Astrophysics Data System (ADS)
Rosaz, G.; Salem, B.; Pauc, N.; Gentile, P.; Potié, A.; Solanki, A.; Baron, T.
2011-08-01
Undoped silicon nanowire (Si NW) field-effect transistors (FETs) with a back-gate configuration have been fabricated and characterized. A thick (200 nm) Si3N4 layer was used as a gate insulator and a p++ silicon substrate as a back gate. Si NWs have been grown by the chemical vapour deposition method using the vapour-liquid-solid mechanism and gold as a catalyst. Metallic contacts have been deposited using Ni/Al (80 nm/120 nm) and characterized before and after an optimized annealing step at 400 °C, which resulted in a great decrease in the contact resistance due to the newly formed nickel silicide/Si interface at source and drain. These optimized devices show a good hole mobility of around 200 cm2 V-1 s-1, in the same range as the bulk material, with a good ON current density of about 28 kA cm-2. Finally, hysteretic behaviour of NW channel conductance is discussed to explain the importance of NW surface passivation.
Weighted Components of i-Government Enterprise Architecture
NASA Astrophysics Data System (ADS)
Budiardjo, E. K.; Firmansyah, G.; Hasibuan, Z. A.
2017-01-01
Lack of government performance, among others due to the lack of coordination and communication among government agencies. Whilst, Enterprise Architecture (EA) in the government can be use as a strategic planning tool to improve productivity, efficiency, and effectivity. However, the existence components of Government Enterprise Architecture (GEA) do not show level of importance, that cause difficulty in implementing good e-government for good governance. This study is to explore the weight of GEA components using Principal Component Analysis (PCA) in order to discovered an inherent structure of e-government. The results show that IT governance component of GEA play a major role in the GEA. The rest of components that consist of e-government system, e-government regulation, e-government management, and application key operational, contributed more or less the same. Beside that GEA from other countries analyzes using comparative base on comon enterprise architecture component. These weighted components use to construct i-Government enterprise architecture. and show the relative importance of component in order to established priorities in developing e-government.
Breech presentation: an audit project as means of pursuing clinical excellence.
Siassakos, D; Anderson, H; Panter, K
2005-10-01
Clinical audit is an effective quality improvement process to evaluate important clinical issues. Breech presentation is such an issue due to its contribution to the rising caesarean section (CS) rate. We set out to assess the management of breech presentation using, as standards, the delivery suite protocol and national guidelines. Our first audit revealed a low success rate of external cephalic version (ECV) and deficient documentation of written consent for ECV, other aspects of care being satisfactory. The results were presented to a multidisciplinary meeting and disseminated to relevant stakeholders. A re-audit was then performed. It confirmed significant improvement in the documentation of consent for ECV. It also revealed a good detection rate of breech, optimal offer rate of ECV and good neonatal outcome. However, uptake of ECV as well as the success rate could both be improved so as to reduce the CS rate for breech presentation. We discuss options for improving the uptake and success rate for ECV.
Qi, Chao; Zhu, Ying-Jie; Wu, Cheng-Tie; Sun, Tuan-Wei; Chen, Feng; Wu, Jin
2016-01-15
Magnesium phosphate materials have aroused interest of researchers in recent years and are promising for biomedical applications due to their good biocompatibility and biodegradability. In this work, we report the microwave-hydrothermal rapid synthesis of magnesium phosphate pentahydrate nanosheets (MPHSs) using biocompatible creatine phosphate as an organic phosphorus source. This method is facile, rapid, surfactant-free and environmentally friendly. The as-prepared MPHSs have an obvious pH-dependent dissolution performance which can be used as an ideal pH-responsive nanocarrier for drug and gene delivery. Moreover, the MPHSs have a good cytocompatibility and a high ability to promote osteoblast MC-3T3 adhesion and spreading, as well as a relatively high protein adsorption ability using hemoglobin (Hb) as a model protein. Thus, the MPHSs are promising for the applications in biomedical fields such as protein adsorption and bone regeneration. Copyright © 2015 Elsevier Inc. All rights reserved.
First spaceborne phase altimetry over sea ice using TechDemoSat-1 GNSS-R signals
NASA Astrophysics Data System (ADS)
Li, Weiqiang; Cardellach, Estel; Fabra, Fran; Rius, Antonio; Ribó, Serni; Martín-Neira, Manuel
2017-08-01
A track of sea ice reflected Global Navigation Satellite System (GNSS) signal collected by the TechDemoSat-1 mission is processed to perform phase altimetry over sea ice. High-precision carrier phase measurements are extracted from coherent GNSS reflections at a high angle of elevation (>57°). The altimetric results show good consistency with a mean sea surface (MSS) model, and the root-mean-square difference is 4.7 cm with an along-track sampling distance of ˜140 m and a spatial resolution of ˜400 m. The difference observed between the altimetric results and the MSS shows good correlation with the colocated sea ice thickness data from Soil Moisture and Ocean Salinity. This is consistent with the reflecting surface aligned with the bottom of the ice-water interface, due to the penetration of the GNSS signal into the sea ice. Therefore, these high-precision altimetric results have potential to be used for determination of sea ice thickness.
Enhancing reproducibility of SALDI MS detection by concentrating analytes within laser spot.
Teng, Fei; Zhu, Qunyan; Wang, Yalei; Du, Juan; Lu, Nan
2018-03-01
Surface-assisted laser desorption/ionization time-of-flight mass spectrometry (SALDI TOF MS) has become one of the most important analytical methods due to its less interference at low molecular weight range. However, it is still a challenge to obtain a good reproducibility of SALDI TOF MS because of the inhomogeneous distribution of analyte molecules induced by coffee ring effect. We propose a universal and reliable method to eliminate the coffee ring effect by concentrating all the analyte molecules within the laser spot. This method exhibits an excellent reproducibility of spot-to-spot and substrate-to-substrate, and the relative standard deviations (RSDs) for different concentrations are lower than 12.6%. It also performs good linear dependency (R 2 > 0.98) in the log-log plot with the concentration range of 1nM to 1μM, and the limit of detection for R6G is down to 1fmol. Copyright © 2017 Elsevier B.V. All rights reserved.
Good outcome after delayed surgery for orbitocranial non-missile penetrating brain injury.
Caporlingua, Alessandro; Caporlingua, Federico; Lenzi, Jacopo
2016-01-01
Nonmissile orbitocranial penetrating brain injuries are uncommonly dealt with in a civilian context. Surgical management is controversial, due to the lack of widely accepted guidelines. A 52-year-old man was hit in his left eye by a metallic foreign body (FB). Head computed tomography (CT) scan showed a left subcortical parietal FB with a considerable hemorrhagic trail originating from the left orbital roof. Surgical treatment was staged; an exenteratio oculi and a left parietal craniotomy to extract the FB under intraoperative CT guidance were performed at post trauma day third and sixth, respectively. A postoperative infectious complication was treated conservatively. The patient retained a right hemiparesis (3/5) and was transferred to rehabilitation in good clinical conditions at day 49(th). He had suspended antiepilectic therapy at that time. A case-by-case tailored approach is mandatory to achieve the best outcome in such a heterogeneous nosological entity. Case reporting is crucial to further understand its mechanism and dynamics.
van Dievoet, M A; Louagie, H; Ghys, T
2016-10-01
The Sysmex XP-300(®) (XP-300) is a new, fully automated hematology analyzer, designed to generate complete blood counts (CBC) with 3-part differential. In our study, the XP-300 was evaluated as a point-of-care (POC) analyzer in an oncology setting. In which blood samples from patients with different pathologies and treatments, affecting hematopoiesis, were analyzed. Performance was evaluated according to the International Council for Standardization in Haematology (ICSH) guidelines and CLSI protocol H20-A2 . Beside precision, linearity and carry-over, a comparison study with the Sysmex(®) XN-3000 (XN-3000) and a manual reference leukocyte differential was performed. Flagging performance was also evaluated. XP-300 showed excellent precision and linearity results. For within- and between-run precision, the criteria, according to Ricos et al. , were met for all parameters tested, except for platelets in the low level. Less than or equal to 0.5% carry-over was seen for all parameters tested. Comparison studies showed an acceptable correlation with both XN-3000 and the manual reference leukocyte count. A suboptimal flagging performance was demonstrated. In the context of diagnosing cytopenia due to myelosuppressing agents or leukocytosis due to infection, the XP-300 showed good analytical performance. However, in the thrombocytopenic range, precision was suboptimal. In follow-up of hematological malignancies with the occurrence of abnormal cells, we advise verification with a more advanced analyzer or with microscopic review, although further studies with a higher prevalence of abnormal cells are needed. © 2016 John Wiley & Sons Ltd.
NASA Astrophysics Data System (ADS)
Ju, Yaping; Zhang, Chuhua
2016-03-01
Blade fouling has been proved to be a great threat to compressor performance in operating stage. The current researches on fouling-induced performance degradations of centrifugal compressors are based mainly on simplified roughness models without taking into account the realistic factors such as spatial non-uniformity and randomness of the fouling-induced surface roughness. Moreover, little attention has been paid to the robust design optimization of centrifugal compressor impellers with considerations of blade fouling. In this paper, a multi-objective robust design optimization method is developed for centrifugal impellers under surface roughness uncertainties due to blade fouling. A three-dimensional surface roughness map is proposed to describe the nonuniformity and randomness of realistic fouling accumulations on blades. To lower computational cost in robust design optimization, the support vector regression (SVR) metamodel is combined with the Monte Carlo simulation (MCS) method to conduct the uncertainty analysis of fouled impeller performance. The analyzed results show that the critical fouled region associated with impeller performance degradations lies at the leading edge of blade tip. The SVR metamodel has been proved to be an efficient and accurate means in the detection of impeller performance variations caused by roughness uncertainties. After design optimization, the robust optimal design is found to be more efficient and less sensitive to fouling uncertainties while maintaining good impeller performance in the clean condition. This research proposes a systematic design optimization method for centrifugal compressors with considerations of blade fouling, providing a practical guidance to the design of advanced centrifugal compressors.
Giannakaki, Venetia; Triantafyllou, Triantafyllos; Drossos, Dimitrios; Papapetrou, Konstantinos
2016-09-01
To present, to our knowledge, the first case of a single bilateral extradural hematoma due to superior sagittal sinus detachment that was treated conservatively with an excellent outcome. Bilateral extradural hematomas are a rare condition, accounting for only 2%-5% of all extradural hematomas. They can be either 2 distinct hematomas on either side or 1 single bilateral hematoma mostly due to sagittal sinus injury, with the latter being the most rare owing to the firm attachment of the sinus to its subperiosteal loggia. These hematomas usually require immediate surgical evacuation, as patients present with decreased level of consciousness, and have good postoperative outcomes. We present a bilateral extradural hematoma due to superior sagittal sinus injury, which was treated conservatively. The patient had an excellent recovery, with no residual neurological deficits and a Glasgow outcome scale of 5 on discharge. Bilateral extradural hematomas due to superior sagittal sinus injury almost always require surgical intervention. We present a patient who was treated conservatively with an excellent outcome and we also perform a review of the current literature. Copyright © 2016 Elsevier Inc. All rights reserved.
Extrapolation From Wind Tunnel to Flight: Shuttle Orbiter Aerodynamics
NASA Technical Reports Server (NTRS)
Muylaert, J.; Walpot, L.; Rostand, P.; Rapuc, M.; Brauckmann, G.; Paulson, J.; Trockmorton, D.; Weilmuenster, K.
1998-01-01
The paper reviews a combined numerical and experimental activity on the Shuttle Orbiter, first performed at NASA Langley within the Orbiter Experiment (OEX) and subsequently at ESA, as part of the AGARD FDP WG 18 activities. The study at Langley was undertaken to resolve the pitch up anomaly observed during the entry of the first flight of the Shuttle Orbiter. The present paper will focus on real gas effects on aerodynamics and not on heating. The facilities used at NASA Langley were the 15-in. Mach 6, the 20-in, Mach 6, the 31-in. Mach 10 and the 20-in. Mach 6 CF4 facility. The paper focuses on the high Mach, high altitude portion of the first entry of the Shuttle where the vehicle exhibited a nose-up pitching moment relative to pre-flight prediction of (Delta C(sub m)) = 0.03. In order to study the relative contribution of compressibility, viscous interaction and real gas effects on basic body pitching moment and flap efficiency, an experimental study was undertaken to examine the effects of Mach, Reynolds and ratio of specific heats at NASA. At high Mach, a decrease of gamma occurs in the shock layer due to high temperature effects. The primary effect of this lower specific heat ratio is a decrease of the pressure on the aft windward expansion surface of the Orbiter causing the nose-up pitching moment. Testing in the heavy gas, Mach 6 CF4 tunnel, gave a good simulation of high temperature effects. The facilities used at ESA were the lm Mach 10 at ONERA Modane, the 0.7 m hot shot F4 at ONERA Le Fauga and the 0.88 m piston driven shock tube HEG at DLR Goettingen. Encouraging good force measurements were obtained in the F4 facility on the Orbiter configuration. Testing of the same model in the perfect gas Mach 10 S4 Modane facility was performed so as to have "reference" conditions. When one compares the F4 and S4 test results, the data suggests that the Orbiter "pitch up" is due to real gas effects. In addition, pressure measurements, performed on the aft portion of the windward side of the Halis configuration in HEG and F4, confirm that the pitch up is mainly attributed to a reduction of pressure due to a local decrease in gamma.
Johnson, Benjamin K; Tierney, David M; Rosborough, Terry K; Harris, Kevin M; Newell, Marc C
2016-02-01
Although focused cardiac ultrasonographic (FoCUS) examination has been evaluated in emergency departments and intensive care units with good correlation to formal echocardiography, accuracy for the assessment of left ventricular systolic function (LVSF) when performed by internal medicine physicians still needs independent evaluation. This prospective observational study in a 640-bed, academic, quaternary care center, included 178 inpatients examined by 10 internal medicine physicians who had completed our internal medicine bedside ultrasound training program. The ability to estimate LVSF with FoCUS as "normal," "mild to moderately decreased," or "severely decreased" was compared with left ventricular ejection fraction (>50%, 31-49%, and <31%, respectively) from formal echocardiography interpreted by a cardiologist. Sensitivity and specificity of FoCUS for any degree of LVSF impairment were 0.91 (95% confidence interval [CI] 0.80, 0.97) and 0.88 (95% CI 0.81, 0.93), respectively. The interrater agreement between internal medicine physician-performed FoCUS and formal echocardiography for any LVSF impairment was "good/substantial" with κ = 0.77 (p < 0.001), 95% CI (0.67, 0.87). Formal echocardiography was classified as "technically limited due to patient factors" in 20% of patients; however, echogenicity was sufficient in 100% of FoCUS exams to classify LVSF. Internal medicine physicians using FoCUS identify normal versus decreased LVSF with high sensitivity, specificity, and "good/substantial" interrater agreement when compared with formal echocardiography. These results support the role of cardiac FoCUS by properly trained internal medicine physicians for discriminating normal from reduced LVSF. © 2015 Wiley Periodicals, Inc.
Practical Framework: Implementing OEE Method in Manufacturing Process Environment
NASA Astrophysics Data System (ADS)
Maideen, N. C.; Sahudin, S.; Mohd Yahya, N. H.; Norliawati, A. O.
2016-02-01
Manufacturing process environment requires reliable machineries in order to be able to satisfy the market demand. Ideally, a reliable machine is expected to be operated and produce a quality product at its maximum designed capability. However, due to some reason, the machine usually unable to achieved the desired performance. Since the performance will affect the productivity of the system, a measurement technique should be applied. Overall Equipment Effectiveness (OEE) is a good method to measure the performance of the machine. The reliable result produced from OEE can then be used to propose a suitable corrective action. There are a lot of published paper mentioned about the purpose and benefit of OEE that covers what and why factors. However, the how factor not yet been revealed especially the implementation of OEE in manufacturing process environment. Thus, this paper presents a practical framework to implement OEE and a case study has been discussed to explain in detail each steps proposed. The proposed framework is beneficial to the engineer especially the beginner to start measure their machine performance and later improve the performance of the machine.
High-performance, polymer-based direct cellular interfaces for electrical stimulation and recording
NASA Astrophysics Data System (ADS)
Kim, Seong-Min; Kim, Nara; Kim, Youngseok; Baik, Min-Seo; Yoo, Minsu; Kim, Dongyoon; Lee, Won-June; Kang, Dong-Hee; Kim, Sohee; Lee, Kwanghee; Yoon, Myung-Han
2018-04-01
Due to the trade-off between their electrical/electrochemical performance and underwater stability, realizing polymer-based, high-performance direct cellular interfaces for electrical stimulation and recording has been very challenging. Herein, we developed transparent and conductive direct cellular interfaces based on a water-stable, high-performance poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) film via solvent-assisted crystallization. The crystallized PEDOT:PSS on a polyethylene terephthalate (PET) substrate exhibited excellent electrical/electrochemical/optical characteristics, long-term underwater stability without film dissolution/delamination, and good viability for primarily cultured cardiomyocytes and neurons over several weeks. Furthermore, the highly crystallized, nanofibrillar PEDOT:PSS networks enabled dramatically enlarged surface areas and electrochemical activities, which were successfully employed to modulate cardiomyocyte beating via direct electrical stimulation. Finally, the high-performance PEDOT:PSS layer was seamlessly incorporated into transparent microelectrode arrays for efficient, real-time recording of cardiomyocyte action potentials with a high signal fidelity. All these results demonstrate the strong potential of crystallized PEDOT:PSS as a crucial component for a variety of versatile bioelectronic interfaces.
Meaningful use and good catches: More appropriate metrics for checklist effectiveness.
Putnam, Luke R; Anderson, Kathryn T; Diffley, Michael B; Hildebrandt, Aubrey A; Caldwell, Kelly M; Minzenmayer, Andrew N; Covey, Sarah E; Kawaguchi, Akemi L; Lally, Kevin P; Tsao, KuoJen
2016-12-01
The benefit of utilizing surgical safety checklists has been recently questioned. We evaluated our checklist performance after implementing a program that includes checklist-related good catches. Multifaceted interventions aimed at the preincision checklist and 5 prospective audits were conducted from 2011-2015. We documented adherence to the checklist (verbalization of each checkpoint), fidelity (meaningful performance of each checkpoint), and good catches (events with the potential to cause the patient harm but that were prevented from occurring). Good catches were divided into quality improvement-based categories (processes, medication, safety, communication, and equipment). A total of 1,346 checklist performances were observed (range, 144-373/yr). Adherence to the preincision checklist improved from 30% to 95% (P < .001), while adherence to the preinduction and debriefing checklists decreased (71% to 56%, P = .002) and remained unchanged (76%), respectively. Preincision fidelity decreased from 86% to 76% (P = .012). Good catches were identified during 16% of preincision checklist performances; process issues were most common (32%) followed by issues of medication administration (30%) and safety (22%). Implementation of a systematic checklist program resulted in significant and sustainable improvement in performance. Meaningful use and associated good catches may be more appropriate metric than actual patient harm for measuring checklist effectiveness. Although not previously described, checklist-related good catches represent an unknown benefit of checklists. Copyright © 2016 Elsevier Inc. All rights reserved.
ERIC Educational Resources Information Center
Fox Garrity, Bonnie
2015-01-01
Postsecondary education in the United States is provided by public, not-for-profit and for-profit institutions. Public and not-for-profit institutions are expected to serve the public good due to state control or chartering requirements; for-profit institutions are not. Therefore, the decision to serve the public good is vested in the board. The…
Can You Show You Are a Good Lecturer?
ERIC Educational Resources Information Center
Wood, Leigh N.; Harding, Ansie
2007-01-01
Measurement of the quality of teaching activities is becoming increasingly important since universities are rewarding performance in terms of promotion, awards and bonuses and research is no longer the only key performance indicator. Good teaching is not easy to identify and measure. This paper specifically deals with the issue of good teaching in…
The Empower project - a new way of assessing and monitoring test comparability and stability.
De Grande, Linde A C; Goossens, Kenneth; Van Uytfanghe, Katleen; Stöckl, Dietmar; Thienpont, Linda M
2015-07-01
Manufacturers and laboratories might benefit from using a modern integrated tool for quality management/assurance. The tool should not be confounded by commutability issues and focus on the intrinsic analytical quality and comparability of assays as performed in routine laboratories. In addition, it should enable monitoring of long-term stability of performance, with the possibility to quasi "real-time" remedial action. Therefore, we developed the "Empower" project. The project comprises four pillars: (i) master comparisons with panels of frozen single-donation samples, (ii) monitoring of patient percentiles and (iii) internal quality control data, and (iv) conceptual and statistical education about analytical quality. In the pillars described here (i and ii), state-of-the-art as well as biologically derived specifications are used. In the 2014 master comparisons survey, 125 laboratories forming 8 peer groups participated. It showed not only good intrinsic analytical quality of assays but also assay biases/non-comparability. Although laboratory performance was mostly satisfactory, sometimes huge between-laboratory differences were observed. In patient percentile monitoring, currently, 100 laboratories participate with 182 devices. Particularly, laboratories with a high daily throughput and low patient population variation show a stable moving median in time with good between-instrument concordance. Shifts/drifts due to lot changes are sometimes revealed. There is evidence that outpatient medians mirror the calibration set-points shown in the master comparisons. The Empower project gives manufacturers and laboratories a realistic view on assay quality/comparability as well as stability of performance and/or the reasons for increased variation. Therefore, it is a modern tool for quality management/assurance toward improved patient care.
Common Characteristics of Good and Poorly Performing PCC Pavements
DOT National Transportation Integrated Search
1998-01-01
This report documents the analysis and findings of a study to identify the site conditions and design/construction features of concrete pavements (JPCP, JRCP, CRCP) that lead to good performance and those that lead to poor performance. Data from Long...
Common Characteristics of Good and Poorly Performing AC Pavements
DOT National Transportation Integrated Search
1999-12-01
This report documents the analysis and findings of a study to identify the site conditions and design/construction features of : flexible pavements that lead to good performance and those that lead to poor performance. Data from the Long Term Pavemen...
Rapid tomographic reconstruction based on machine learning for time-resolved combustion diagnostics
NASA Astrophysics Data System (ADS)
Yu, Tao; Cai, Weiwei; Liu, Yingzheng
2018-04-01
Optical tomography has attracted surged research efforts recently due to the progress in both the imaging concepts and the sensor and laser technologies. The high spatial and temporal resolutions achievable by these methods provide unprecedented opportunity for diagnosis of complicated turbulent combustion. However, due to the high data throughput and the inefficiency of the prevailing iterative methods, the tomographic reconstructions which are typically conducted off-line are computationally formidable. In this work, we propose an efficient inversion method based on a machine learning algorithm, which can extract useful information from the previous reconstructions and build efficient neural networks to serve as a surrogate model to rapidly predict the reconstructions. Extreme learning machine is cited here as an example for demonstrative purpose simply due to its ease of implementation, fast learning speed, and good generalization performance. Extensive numerical studies were performed, and the results show that the new method can dramatically reduce the computational time compared with the classical iterative methods. This technique is expected to be an alternative to existing methods when sufficient training data are available. Although this work is discussed under the context of tomographic absorption spectroscopy, we expect it to be useful also to other high speed tomographic modalities such as volumetric laser-induced fluorescence and tomographic laser-induced incandescence which have been demonstrated for combustion diagnostics.
Rapid tomographic reconstruction based on machine learning for time-resolved combustion diagnostics.
Yu, Tao; Cai, Weiwei; Liu, Yingzheng
2018-04-01
Optical tomography has attracted surged research efforts recently due to the progress in both the imaging concepts and the sensor and laser technologies. The high spatial and temporal resolutions achievable by these methods provide unprecedented opportunity for diagnosis of complicated turbulent combustion. However, due to the high data throughput and the inefficiency of the prevailing iterative methods, the tomographic reconstructions which are typically conducted off-line are computationally formidable. In this work, we propose an efficient inversion method based on a machine learning algorithm, which can extract useful information from the previous reconstructions and build efficient neural networks to serve as a surrogate model to rapidly predict the reconstructions. Extreme learning machine is cited here as an example for demonstrative purpose simply due to its ease of implementation, fast learning speed, and good generalization performance. Extensive numerical studies were performed, and the results show that the new method can dramatically reduce the computational time compared with the classical iterative methods. This technique is expected to be an alternative to existing methods when sufficient training data are available. Although this work is discussed under the context of tomographic absorption spectroscopy, we expect it to be useful also to other high speed tomographic modalities such as volumetric laser-induced fluorescence and tomographic laser-induced incandescence which have been demonstrated for combustion diagnostics.
Experimental verification of Space Platform battery discharger design optimization
NASA Astrophysics Data System (ADS)
Sable, Dan M.; Deuty, Scott; Lee, Fred C.; Cho, Bo H.
The detailed design of two candidate topologies for the Space Platform battery discharger, a four module boost converter (FMBC) and a voltage-fed push-pull autotransformer (VFPPAT), is presented. Each has unique problems. The FMBC requires careful design and analysis in order to obtain good dynamic performance. This is due to the presence of a right-half-plane (RHP) zero in the control-to-output transfer function. The VFPPAT presents a challenging power stage design in order to yield high efficiency and light component weight. The authors describe the design of each of these converters and compare their efficiency, weight, and dynamic characteristics.
Graphene rectenna for efficient energy harvesting at terahertz frequencies
NASA Astrophysics Data System (ADS)
Dragoman, Mircea; Aldrigo, Martino
2016-09-01
In this paper, we propose a graphene rectenna that encompasses two distinct functions in a single device, namely, antenna and rectifier, which till now were two separate components. In this way, the rectenna realizes an efficient energy harvesting technique due to the absence of impedance mismatch between antenna and diode. In particular, we have obtained a maximum conversion efficiency of 58.43% at 897 GHz for the graphene rectenna on n-doped GaAs, which is a very good value, close to the performance of an RF harvesting system. A comparison with a classical metallic antenna with an HfO2-based metal-insulator-metal diode is also provided.
Optical and electrical studies of cerium mixed oxides
NASA Astrophysics Data System (ADS)
Sherly, T. R.; Raveendran, R.
2014-10-01
The fast development in nanotechnology makes enthusiastic interest in developing nanomaterials having tailor made properties. Cerium mixed oxide materials have received great attention due to their UV absorption property, high reactivity, stability at high temperature, good electrical property etc and these materials find wide applications in solid oxide fuel cells, solar control films, cosmetics, display units, gas sensors etc. In this study cerium mixed oxide compounds were prepared by co-precipitation method. All the samples were doped with Zn (II) and Fe (II). Preliminary characterizations such as XRD, SEM / EDS, TEM were done. UV - Vis, Diffuse reflectance, PL, FT-IR, Raman and ac conductivity studies of the samples were performed.
Electrodeposited highly-ordered manganese oxide nanowire arrays for supercapacitors
NASA Astrophysics Data System (ADS)
Liu, Haifeng; Lu, Bingqiang; Wei, Shuiqiang; Bao, Mi; Wen, Yanxuan; Wang, Fan
2012-07-01
Large arrays of well-aligned Mn oxide nanowires were prepared by electrodeposition using anodic aluminum oxide templates. The sizes of nanowires were tuned by varying the electrotype solution involved and the MnO2 nanowires with 10 μm in length were obtained in a neutral KMnO4 bath for 1 h. MnO2 nanowire arrays grown on conductor substance save the tedious electrode-making process, and electrochemical characterization demonstrates that the MnO2 nanowire arrays electrode has good capacitive behavior. Due to the limited mass transportation in narrow spacing, the spacing effects between the neighbor nanowires have show great influence to the electrochemical performance.
A Polymer Optical Fiber Fuel Level Sensor: Application to Paramotoring and Powered Paragliding
Montero, David Sánchez; Lallana, Pedro Contreras; Vázquez, Carmen
2012-01-01
A low-cost intensity-based polymer optical fiber (POF) sensor for fuel level measurements in paramotoring and powered paragliding is presented, exploiting the advantages of the optical fiber sensing technology. Experimental results demonstrate that the best option can be performed by stripping the fiber at the desired discrete points to measure the fuel level as well as with a gauge-shape fiber bending. The prototype has a good linearity, better than 4% full scale (F.S.), and sensitivity around 0.5 V per bend are obtained. Hysteresis due to residual fluid at the sensing points is found to be less than 9% F.S. PMID:22778637
Polypyrrole based nanocomposites for supercapacitor applications: A review
NASA Astrophysics Data System (ADS)
Sardar, A.; Gupta, P. S.
2018-05-01
Recently conducting polymers have attracted great interest for supercapacitor applications. Among conducting polymers polypyrrole is most popular due to its unique electrical conductivity, optoelectrical properties, redox property and excellent environmental stability. In this article, we present a comprehensive review of polypyrrole and polypyrrole based nanocomposites for supercapacitor applications. We have included study of various parameters like power density, energy density, specific-capacitance by various authors for different kinds of nanocomposites where fillers are metal oxides, metal sulphides, graphene etc. Some polypyrrole nanocomposits show good electrochemical performances. The extremely stable supercapacitors with excellent flexibility and scalability hold considerable promise for the commerical application of flexible and wearable electronics.
Development of PLA hybrid yarns for biobased self-reinforced polymer composites
NASA Astrophysics Data System (ADS)
Köhler, T.; Gries, T.; Seide, G.
2017-10-01
Lightweight materials are a necessity in various industries. Lightweight design is in the key interest of the mobility sector, e.g. the automotive and aerospace industry. This trend applies also for the consumer industries, e.g. sporting goods. In addition, the worldwide demand for replacing fossil-based materials has led to a significant growth of bioplastics. Due to their low mechanical performance and durability, their use is still limited. Therefore, it is necessary to develop biobased, sustainable polymeric materials with high stiffness, high impact and high durability without impairing recyclability at a similar price level of non-biobased solutions. Biobased self-reinforced polymer composites offer these unique properties.
Homogenization kinetics of a nickel-based superalloy produced by powder bed fusion laser sintering
DOE Office of Scientific and Technical Information (OSTI.GOV)
Zhang, Fan; Levine, Lyle E.; Allen, Andrew J.
2017-04-01
Additively manufactured (AM) metal components often exhibit fine dendritic microstructures and elemental segregation due to the initial rapid solidification and subsequent melting and cooling during the build process, which without homogenization would adversely affect materials performance. In this letter, we report in situ observation of the homogenization kinetics of an AM nickel-based superalloy using synchrotron small angle X-ray scattering. The identified kinetic time scale is in good agreement with thermodynamic diffusion simulation predictions using microstructural dimensions acquired by ex situ scanning electron microscopy. These findings could serve as a recipe for predicting, observing, and validating homogenization treatments in AM materials.
Homogenization Kinetics of a Nickel-based Superalloy Produced by Powder Bed Fusion Laser Sintering.
Zhang, Fan; Levine, Lyle E; Allen, Andrew J; Campbell, Carelyn E; Lass, Eric A; Cheruvathur, Sudha; Stoudt, Mark R; Williams, Maureen E; Idell, Yaakov
2017-04-01
Additively manufactured (AM) metal components often exhibit fine dendritic microstructures and elemental segregation due to the initial rapid solidification and subsequent melting and cooling during the build process, which without homogenization would adversely affect materials performance. In this letter, we report in situ observation of the homogenization kinetics of an AM nickel-based superalloy using synchrotron small angle X-ray scattering. The identified kinetic time scale is in good agreement with thermodynamic diffusion simulation predictions using microstructural dimensions acquired by ex situ scanning electron microscopy. These findings could serve as a recipe for predicting, observing, and validating homogenization treatments in AM materials.
Experimental verification of Space Platform battery discharger design optimization
NASA Technical Reports Server (NTRS)
Sable, Dan M.; Deuty, Scott; Lee, Fred C.; Cho, Bo H.
1991-01-01
The detailed design of two candidate topologies for the Space Platform battery discharger, a four module boost converter (FMBC) and a voltage-fed push-pull autotransformer (VFPPAT), is presented. Each has unique problems. The FMBC requires careful design and analysis in order to obtain good dynamic performance. This is due to the presence of a right-half-plane (RHP) zero in the control-to-output transfer function. The VFPPAT presents a challenging power stage design in order to yield high efficiency and light component weight. The authors describe the design of each of these converters and compare their efficiency, weight, and dynamic characteristics.
FEM Analysis of Glass/Epoxy Composite Based Industrial Safety Helmet
NASA Astrophysics Data System (ADS)
Ram, Khushi; Bajpai, Pramendra Kumar
2017-08-01
Recently, the use of fiber reinforced polymer in every field of engineering (automobile, industry and aerospace) and medical has increased due to its distinctive mechanical properties. The fiber based polymer composites are more popular because these have high strength, light in weight, low cost and easily available. In the present work, the finite element analysis (FEA) of glass/epoxy composite based industrial safety helmet has been performed using solid-works simulation software. The modeling results show that glass fiber reinforced epoxy composite can be used as a material for fabrication of industrial safety helmet which has good mechanical properties than the existing helmet material.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Li Shun; School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing, 100083; Lin Yuanhua
Nanostructured BiFeO{sub 3} particles have been synthesized by a hydrothermal method, and the effects of particle size on photocatalytic activity and magnetic property of BiFeO{sub 3} were investigated. The optical absorption spectra indicate that the band-gap energy increases with decreasing crystalline size due to the quantum-size effect. The enhancement of room-temperature weak ferromagnetism can be observed in nanoscale BiFeO{sub 3} particles, which should be attributed to the size-confinement effect on the magnetic ordering. In addition, BiFeO{sub 3} nanoparticles with diameter about 5 nm show good photocatalytic performance by photodegradation of Congo red under visible-light ({lambda}>400 nm) irradiation.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Wang, Lizhong; Ouyang, Shuxin; Ren, Bofan
2015-10-01
Macroporous GaN/ZnO solid solution photocatalyst is synthesized through a novel sol-gel method under mild conditions. The performance of as-synthesized solid solution photocatalyst is evaluated for decomposition of gaseous 2-propanol (IPA). It is found that due to enhancement in both the adsorption to gaseous IPA and the absorbance to visible light, the porous GaN/ZnO solid solution exhibits a good photocatalytic performance for IPA decomposition. Moreover, the mechanism for photocatalytic degradation IPA over porous GaN/ZnO solid solution is also investigated in comparison with those for the two end materials ZnO and GaN. The trapping effects with different scavengers prove that both themore » photoexcited electrons and holes affect the IPA photodegradation process, simultaneously.« less
Prediction on carbon dioxide emissions based on fuzzy rules
NASA Astrophysics Data System (ADS)
Pauzi, Herrini; Abdullah, Lazim
2014-06-01
There are several ways to predict air quality, varying from simple regression to models based on artificial intelligence. Most of the conventional methods are not sufficiently able to provide good forecasting performances due to the problems with non-linearity uncertainty and complexity of the data. Artificial intelligence techniques are successfully used in modeling air quality in order to cope with the problems. This paper describes fuzzy inference system (FIS) to predict CO2 emissions in Malaysia. Furthermore, adaptive neuro-fuzzy inference system (ANFIS) is used to compare the prediction performance. Data of five variables: energy use, gross domestic product per capita, population density, combustible renewable and waste and CO2 intensity are employed in this comparative study. The results from the two model proposed are compared and it is clearly shown that the ANFIS outperforms FIS in CO2 prediction.
A new biomechanical hand prosthesis controlled by surface electromyographic signals.
Andrade, Nei A; Borges, Geovany A; de O Nascimento, Francisco A; Romariz, Alexandre R S; da Rocha, Adson F
2007-01-01
This paper describes the development of a low-cost hand prosthesis for use in patients with an amputated hand due to congenital problems or to trauma wound, who possess a part or the forearm endowed with muscular activity. The paper covers the constructive aspects of both mechanical and electronic designs. The prototype is controlled by electromyographic signals measured at the remaining part of the injured limb of the patient. The EMG signals are measured at the surface of the skin, at a point that is close to a working muscle of the amputated arm. The prosthesis allows the patient to hold objects by means of a three finger clamp. The prosthesis presented an excellent performance in preliminary tests with an amputated patient. These tests showed that the prosthesis had a very good performance regarding force and speed.
Guidez, Emilie B; Gordon, Mark S
2015-03-12
The modeling of dispersion interactions in density functional theory (DFT) is commonly performed using an energy correction that involves empirically fitted parameters for all atom pairs of the system investigated. In this study, the first-principles-derived dispersion energy from the effective fragment potential (EFP) method is implemented for the density functional theory (DFT-D(EFP)) and Hartree-Fock (HF-D(EFP)) energies. Overall, DFT-D(EFP) performs similarly to the semiempirical DFT-D corrections for the test cases investigated in this work. HF-D(EFP) tends to underestimate binding energies and overestimate intermolecular equilibrium distances, relative to coupled cluster theory, most likely due to incomplete accounting for electron correlation. Overall, this first-principles dispersion correction yields results that are in good agreement with coupled-cluster calculations at a low computational cost.
Camboulives, A-R; Velluet, M-T; Poulenard, S; Saint-Antonin, L; Michau, V
2018-02-01
An optical communication link performance between the ground and a geostationary satellite can be impaired by scintillation, beam wandering, and beam spreading due to its propagation through atmospheric turbulence. These effects on the link performance can be mitigated by tracking and error correction codes coupled with interleaving. Precise numerical tools capable of describing the irradiance fluctuations statistically and of creating an irradiance time series are needed to characterize the benefits of these techniques and optimize them. The wave optics propagation methods have proven their capability of modeling the effects of atmospheric turbulence on a beam, but these are known to be computationally intensive. We present an analytical-numerical model which provides good results on the probability density functions of irradiance fluctuations as well as a time series with an important saving of time and computational resources.
Dhakal, Ajay; Chen, Hongbin; Dexter, Elisabeth U
2017-12-01
A 51-year-old woman was found to have a new 14 × 6 mm soft tissue mass under the right serratus muscle on a CT scan of the chest performed for routine surveillance due to her history of stage I lung cancer. A follow-up CT scan performed 4 months later showed that the mass had increased in size to 22 × 8 mm. The patient presents to the oncology clinic to discuss the results of the CT scan. She has no pain or swelling on the right lateral chest and no cough, fever, or shortness of breath. She is at her baseline health with good appetite and functional status. Copyright © 2017 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.
Neroladaki, Angeliki; Breguet, Romain; Botsikas, Diomidis; Terraz, Sylvain; Becker, Christoph D; Montet, Xavier
2012-07-23
Computed tomography colonography, or virtual colonoscopy, is a good alternative to optical colonoscopy. However, suboptimal patient preparation or colon distension may reduce the diagnostic accuracy of this imaging technique. We report the case of an 83-year-old Caucasian woman who presented with a five-month history of pneumaturia and fecaluria and an acute episode of macrohematuria, leading to a high clinical suspicion of a colovesical fistula. The fistula was confirmed by standard contrast-enhanced computed tomography. Optical colonoscopy was performed to exclude the presence of an underlying colonic neoplasm. Since optical colonoscopy was incomplete, computed tomography colonography was performed, but also failed due to inadequate colon distension. The insufflated air directly accumulated within the bladder via the large fistula. Clinicians should consider colovesical fistula as a potential reason for computed tomography colonography failure.
Finite element modelling for mode-I fracture behaviour of CFRP
NASA Astrophysics Data System (ADS)
Chetan, H. C.; Kattimani, Subhaschandra; Murigendrappa, S. M.
2018-04-01
Debonding is a major failure mechanism in Carbon Fiber Reinforced Polymer (CFRP) due to presence of many adhesion joins, in between many layers. In the current study a finite element simulation is carried out using Virtual Crack Closure Technique (VCCT) and Cohesive Zone Modelling (CZM) using Abaqus as analysis tool. A comparative study is performed in to order analyze convergence of results from CZM and VCCT. It was noted that CZM results matched well with published literature. The results from VCCT were also in good comparison with experimental data of published literature, but were seen to be overestimated. Parametric study is performed to evaluate the variation of input parameters like initial stiffness, element size, peak stress and energy release rate `G'. From the numerical evaluation, it was noted that CZM simulation relies largely on element size and peak stress.
[Study on the traditional lime mortar from the memorial archway in the southern Anhui province].
Wei, Guo-Feng; Sun, Sheng; Wang, Cheng-Xing; Zhang, Bing-Jian; Chen, Xi-Min
2013-07-01
The traditional lime mortar was investigated by means of scanning electron microscope (SEM), X-ray diffractometry and Fourier transform infrared spectrometry (FTIR). The results show that the mortar from the memorial archway in the southern Anhui province was the organic-inorganic composite materials composed of lime with tung oil or sticky rice. It was found that the excellent performance of the tung oil-lime mortar can be explained by the compact lamellar organic-inorganic composite structure that was produced by carbonization reaction of lime, cross-linking reactions of tung oil and oxygen and complexing reaction of Ca2+ and -COO-. The compact micro-structure of sticky rice-lime mortar, which was produced due to carbonation process of lime controlled by amylopectin, should be the cause of the good performance of this kind of organic-inorganic mortar.
Komori, Shuji; Kawai, Masahiko; Nitta, Toyoo; Murase, Yusuke; Matsumoto, Keita; Shinoda, Chika; Kuno, Masashi; Sasaguri, Yuki; Fukada, Masahiro; Asano, Yoshimi; Kiyama, Shigeru; Tanaka, Chihiro; Nagao, Yasuko; Nagao, Narutoshi; Kunieda, Katsuyuki
2016-02-24
Carcinoma and adenoma of the duodenum, including the papilla of Vater, are problematic diseases in patients with familial adenomatous polyposis (FAP). A 36-year-old man underwent a periodic medical examination for early colon cancer originating from FAP for which laparoscopic-assisted subtotal colectomy with a J-shaped ileal pouch-rectal anastomosis was performed 3 years earlier. A tumor was detected at the papilla of Vater along with elevation of total bilirubin and hepatobiliary enzymes. Although cytology did not determine the tumor to be an adenocarcinoma, we suspected adenocarcinoma due to its hypervascularity shown by contrast-enhanced computed tomography. Pylorus-preserving pancreaticoduodenectomy with modified Imanaga reconstruction and regional lymph node dissection (D2) was performed. The pathological study showed that the tumor was a papillary and moderately differentiated tubular adenocarcinoma. The patient is currently in good health without recurrence, weight loss, or severe diarrhea at 12 months after surgery. Awareness of biliary-pancreatic symptoms and periodic gastroduodenoscopy might contribute both to the early detection of duodenal or periampullary polyps and cancer and to the radical treatment of FAP. Modified Imanaga reconstruction has the potential to become one of the more effective procedures for providing good quality of life to FAP patients with duodenal or periampullary cancer.
NASA Astrophysics Data System (ADS)
Kong, Dewang; Yuan, Wenjing; Li, Cun; Song, Jiming; Xie, Anjian; Shen, Yuhua
2017-01-01
Developing efficient and economical catalysts for the oxygen reduction reaction (ORR) is important to promote the commercialization of fuel cells. Here, we report a simple and environmentally friendly method to prepare nitrogen (N) -doped hierarchical porous carbon (HPC)/reduced graphene oxide (RGO) composites by reusing waste biomass (pomelo peel) coupled with graphene oxide (GO). This method is green, low-cost and without using any acid or alkali activator. The typical sample (N-HPC/RGO-1) contains 5.96 at.% nitrogen and larger BET surface area (1194 m2/g). Electrochemical measurements show that N-HPC/RGO-1 exhibits not only a relatively positive onset potential and high current density, but also considerable methanol tolerance and long-term durability in alkaline media as well as in acidic media. The electron transfer number is close to 4, which means that it is mostly via a four-electron pathway toward ORR. The excellent catalytic performance of N-HPC/RGO-1 is due to the synergistic effect of the inherent interwoven network structure of HPC, the good electrical conductivity of RGO, and the heteroatom doping for the composite. More importantly, this work demonstrates a good example for turning discarded rubbish into valuable functional products and addresses the disposal issue of waste biomass simultaneously for environment clean.
NASA Astrophysics Data System (ADS)
Musa, Y.; Hashim, S.; Karim, M. K. A.; Bakar, K. A.; Ang, W. C.; Salehhon, N.
2017-05-01
The use of optically stimulated luminescence (OSL) for dosimetry applications has recently increased considerably due to availability of commercial OSL dosimeters (nanoDots) for clinical use. The OSL dosimeter has a great potential to be used in clinical dosimetry because of its prevailing advantages in both handling and application. However, utilising nanoDot OSLDs for dose measurement in diagnostic radiology can only be guaranteed when the performance and characteristics of the dosimeters are apposite. In the present work, we examined the response of commercially available nanoDot OSLD (Al2O3:C) subjected to X-rays in general radiography. The nanoDots response with respect to reproducibility, dose linearity and signal depletion were analysed using microStar reader (Landauer, Inc., Glenwood, IL). Irradiations were performed free-in-air using 70, 80 and 120 kV tube voltages and tube currents ranging from 10 - 100 mAs. The results showed that the nanoDots exhibit good linearity and reproducibility when subjected to diagnostic X-rays, with coefficient of variations (CV) ranging between 2.3% to 3.5% representing a good reproducibility. The results also indicated average of 1% signal reduction per readout. Hence, the nanoDots showed a promising potential for dose measurement in general X-ray procedure.
New in-situ neutron diffraction cell for electrode materials
NASA Astrophysics Data System (ADS)
Biendicho, Jordi Jacas; Roberts, Matthew; Offer, Colin; Noréus, Dag; Widenkvist, Erika; Smith, Ronald I.; Svensson, Gunnar; Edström, Kristina; Norberg, Stefan T.; Eriksson, Sten G.; Hull, Stephen
2014-02-01
A novel neutron diffraction cell has been constructed to allow in-situ studies of the structural changes in materials of relevance to battery applications during charge/discharge cycling. The new design is based on the coin cell geometry, but has larger dimensions compared to typical commercial batteries in order to maximize the amount of electrode material and thus, collect diffraction data of good statistical quality within the shortest possible time. An important aspect of the design is its modular nature, allowing flexibility in both the materials studied and the battery configuration. This paper reports electrochemical tests using a Nickel-metal-hydride battery (Ni-MH), which show that the cell is able to deliver 90% of its theoretical capacity when using deuterated components. Neutron diffraction studies performed on the Polaris diffractometer using nickel metal and a hydrogen-absorbing alloy (MH) clearly show observable changes in the neutron diffraction patterns as a function of the discharge state. Due to the high quality of the diffraction patterns collected in-situ (i.e. good peak-to-background ratio), phase analysis and peak indexing can be performed successfully using data collected in around 30 min. In addition to this, structural parameters for the β-phase (charged) MH electrode obtained by Rietveld refinement are presented.
Non-enzymatic glucose sensor based on electrodeposited copper on carbon paste electrode (Cu/CPE)
DOE Office of Scientific and Technical Information (OSTI.GOV)
Nurani, Dita Arifa, E-mail: d.arifa@sci.ui.ac.id; Wibowo, Rahmat; Fajri, Iqbal Farhan El
The development of non-enzymatic glucose sensor has much attention due to their applications in glucose monitoring. In this research, copper oxide is used as a non-enzymatic glucose sensor by oxidizing glucose to gluconolactone. Copper was electrodeposited on Carbon paste electrode (CPE) at constant potential. The experimental condition was varied in electrodeposition of Cu with the following parameters: Electrodeposition time 60 s, 120 s and 180 s and potential reduction -0.166 V, -0.266 V and -0.366 V. The effective performance of these working electrodes in sensing glucose was investigated. The Cu/CPE which used -0.366 V potential reduction and 120 s electrodeposition time shows the bestmore » performance. The amperometric response current in concentration range 1.6-62.5 mM of glucose gives the good linearity R{sup 2} = 0.9988, low detection limit 0.6728 mM and high sensitivity 1183.59 µA mM{sup −1}cm{sup −2}. Furthermore this sensor exhibited a good repeatability with %RSD = 1.31% (n=10) and high stability with %RSD = 1.51% (n=5 days). The homogeneity of Cu particles on CPE was investigated by Scanning Electron Microscope (SEM).« less
Observational tests for Λ(t)CDM cosmology
DOE Office of Scientific and Technical Information (OSTI.GOV)
Pigozzo, C.; Carneiro, S.; Dantas, M.A.
2011-08-01
We investigate the observational viability of a class of cosmological models in which the vacuum energy density decays linearly with the Hubble parameter, resulting in a production of cold dark matter particles at late times. Similarly to the flat ΛCDM case, there is only one free parameter to be adjusted by the data in this class of Λ(t)CDM scenarios, namely, the matter density parameter. To perform our analysis we use three of the most recent SNe Ia compilation sets (Union2, SDSS and Constitution) along with the current measurements of distance to the BAO peaks at z = 0.2 and zmore » = 0.35 and the position of the first acoustic peak of the CMB power spectrum. We show that in terms of χ{sup 2} statistics both models provide good fits to the data and similar results. A quantitative analysis discussing the differences in parameter estimation due to SNe light-curve fitting methods (SALT2 and MLCS2k2) is studied using the current SDSS and Constitution SNe Ia compilations. A matter power spectrum analysis using the 2dFGRS is also performed, providing a very good concordance with the constraints from the SDSS and Constitution MLCS2k2 data.« less
Perceptions of health and risk management among home care workers in Sweden.
Larsson, A; Karlqvist, L; Westerberg, M; Gard, G
2013-10-01
Municipal home care workers provide high-quality services to an increasing proportion of elderly people living in private homes. The work environments and working conditions of these workers vary to a great extent, implying rapid priority-making among both employers and employees to ensure that the work can be performed in a safe way. This study aims to examine home care workers' perceptions of health, risks, working conditions, and risk management within their organization. The study was based on cross-sectional data collected from home care service staff in a municipality in the north of Sweden. Nursing assistants and care aides ( n = 133) replied to a self-administered questionnaire. Descriptive statistics and between-group differences were analysed. Home care work was perceived to require high levels of professional skill and ingenuity, a good psychosocial work situation, but required a high physical workload. The general health, the capacity and self-efficacy of the staff in relation to work were good. Difficulty in performing risk assessments and following safety regulations due to lack of time, equipment, and information were identified. There is a need to increase participation in risk assessments among the staff, improve management support, structures, and cooperation with other divisions of the social services and the medical care organizations.
Germine, Laura; Nakayama, Ken; Duchaine, Bradley C; Chabris, Christopher F; Chatterjee, Garga; Wilmer, Jeremy B
2012-10-01
With the increasing sophistication and ubiquity of the Internet, behavioral research is on the cusp of a revolution that will do for population sampling what the computer did for stimulus control and measurement. It remains a common assumption, however, that data from self-selected Web samples must involve a trade-off between participant numbers and data quality. Concerns about data quality are heightened for performance-based cognitive and perceptual measures, particularly those that are timed or that involve complex stimuli. In experiments run with uncompensated, anonymous participants whose motivation for participation is unknown, reduced conscientiousness or lack of focus could produce results that would be difficult to interpret due to decreased overall performance, increased variability of performance, or increased measurement noise. Here, we addressed the question of data quality across a range of cognitive and perceptual tests. For three key performance metrics-mean performance, performance variance, and internal reliability-the results from self-selected Web samples did not differ systematically from those obtained from traditionally recruited and/or lab-tested samples. These findings demonstrate that collecting data from uncompensated, anonymous, unsupervised, self-selected participants need not reduce data quality, even for demanding cognitive and perceptual experiments.
Shahzadi, Kiran; Zhang, Xueming; Mohsin, Imran; Ge, Xuesong; Jiang, Yijun; Peng, Hui; Liu, Huizhou; Li, Hui; Mu, Xindong
2017-06-27
In this article, a simple strategy was employed to fabricate bioinspired hybrid composite with carboxymethyl cellulose (CMC), graphene oxide, and reduced graphene oxide/alumina (rGO/Al) by a facile solution casting method. The tensile strength and toughness of rGO/Al-CMC-GO can reach 586.6 ± 12 MPa, 12.1 ± 0.44 MJm -3 , respectively, due to the interface strengthening of alumina, which is 1.43 and 12 times higher than steel and about 4.3 and 6.7 times that of nature nacre. The artificial nacre hybrid composite is conductive due to the introduction of rGO/Al on the surface. Interestingly this structure can also be coated on the surface of cotton thread to give the thread good mechanical performance and conductivity. Additionally, the artificial nacre has better fire shielding and gas barrier properties. The oxygen permeability (OP) for 1% rGO/Al-CMC decreased from 0.0265 to 0.003 mLμm m -2 day -1 kpa -1 , the water vapor permeability (WVP) decreased from 0.363 to 0.205 gmmm -2 day -1 kpa -1 when the concentration increased from 1% rGO/Al to 6% rGO/Al. It is believed this work provided a simple and feasible strategy to fabricate ultrastrong and ultratough graphene-based artificial nacre multifunctional materials.
Regularized minimum I-divergence methods for the inverse blackbody radiation problem
NASA Astrophysics Data System (ADS)
Choi, Kerkil; Lanterman, Aaron D.; Shin, Jaemin
2006-08-01
This paper proposes iterative methods for estimating the area temperature distribution of a blackbody from its total radiated power spectrum measurements. This is called the inverse blackbody radiation problem. This problem is inherently ill-posed due to the characteristics of the kernel in the underlying integral equation given by Planck's law. The functions involved in the problem are all non-negative. Csiszár's I-divergence is an information-theoretic discrepancy measure between two non-negative functions. We derive iterative methods for minimizing Csiszár's I-divergence between the measured power spectrum and the power spectrum arising from the estimate according to the integral equation. Due to the ill-posedness of the problem, unconstrained algorithms often produce poor estimates, especially when the measurements are corrupted by noise. To alleviate this difficulty, we apply regularization methods to our algorithms. Penalties based on Shannon's entropy, the L1-norm and Good's roughness are chosen to suppress the undesirable artefacts. When a penalty is applied, the pertinent optimization that needs to be performed at each iteration is no longer trivial. In particular, Good's roughness causes couplings between estimate components. To handle this issue, we adapt Green's one-step-late method. This choice is based on the important fact that our minimum I-divergence algorithms can be interpreted as asymptotic forms of certain expectation-maximization algorithms. The effectiveness of our methods is illustrated via various numerical experiments.
[Oral morphine in the treatment of patients with terminal disease].
Manzini, J L; Somoza, E J; Fridlender, H I
1990-01-01
From May 1986 until July 1987, oral morphine hydrochloride in water solution was used in terminal patients, under a strict protocol of administration, and complying with the basic principles of Palliative Care. A retrospective study was carried out on the 40 patients who had received the drug for more than three consecutive days. As shown in Table 1, the average age of the treated patients was 70 years. The ambulatory patients represented 27.5% of the sample. The average initial dose was 60 mg, and the average maintenance dose was 120 mg. The median treatment time was 45 days. "Good" results were achieved in 85% of the patients, and "fairly good" in the remainder ("good" results were defined as "satisfactory symptom control, good life quality"--in this group there were some patients who obtained total suppression of the symptoms and optimal life-quality, i.e. "excellent" results; "bad" results were defined as "total absence of therapeutic effect"; and "fairly good" results, the intermediate cases). The more frequently treated symptoms were: 67.5%, pain due to tumor mass; and 20%, pain due to nerve compression-invasion, bone pain, and dyspnoea due to pulmonary metastases or primary lung cancer: total symptoms was more than a hundred per cent, because a number of patients had more than one symptom. Whenever necessary, adjuvant drugs were employed. Side effects were seen in 37% of the patients (specially nausea, vomiting, constipation, and somnolence for more than four days).(ABSTRACT TRUNCATED AT 250 WORDS)
Reading comprehension and expressive writing: a comparison between good and poor comprehenders.
Carretti, Barbara; Re, Anna Maria; Arfè, Barbara
2013-01-01
This study investigated expressive writing in 8- to 10-year-old children with different levels of reading comprehension. Poor and good comprehenders were presented with three expressive writing tasks where the modality (pictorial vs. verbal) and the text genre (narrative vs. descriptive) varied. Results showed that poor comprehenders' performance was minimally influenced by the modality of the prompt. In fact, their performance was generally worse than that of good comprehenders and affected by the text genre, as the quality of their narratives was generally lower than that of good comprehenders. However, in the descriptive text condition, their performance was comparable to that of good comprehenders. One can conclude that their problems depend on the characteristics of the narrative text where coherence and causality are important elements.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Clark, Williams; Zhao, Ji-Cheng
Cost effective and high performance alloys that are capable of operating at 760 °C or higher for extended periods of time under a very aggressive environment are critically required for the design and development of advanced ultrasupercritical (AUSC) boilers and steam turbines. Finely dispersed Laves phase precipitates have been shown by Takeyama and co-workers to be a viable strengthening mechanism in high temperature austenitic steels. There is currently no straightforward theory that can predict what other intermetallic phases can serve as potent precipitation-strengthening phases for steels; thus we employed a highly effective dual-anneal diffusion multiple (DADM) approach to screen formore » viable strengthening precipitates over a wide range of compositions. From the Fe-Co-Cr-Ni-Mo DADMs, the Fe-Cr-Mo based Chi phase was identified as a new strengthening phase for high temperature ferritic steels; and from the Fe-Mn-Cr-Nb-Ni-Mo-FeAl DADMs, the Laves phase was identified as a viable strengthening precipitate in Fe-Mn and Fe-Ni based austenitic steels. After identification of viable strengthening phases from the DADMs that covered compositions in the basic ternary and quaternary systems, we employed computation thermodynamics to perform multicomponent alloy design and optimization. For the new the Chi-phase strengthened steels, we performed thermodynamic calculations to vary the volume fraction of the Chi phase and introduced Nb and carbon to promote the formation of stable carbides for grain size control during solution heat treatment. For the Fe-Ni-Mn based austenitic steels, we performed extensive parametric optimization of compositions in order to reduce the expensive Ni content, add Cr and Al for oxidation resistance, and balance the alloying contents (Ni, Mn, Cr, Al, Mo) to suppress the ferritic phase and promote the austenitic matrix phase. Four steels (two ferritic + two austenitic) were designed and tested. The two Chi-phase strengthened ferritic steels exhibited excellent oxidation resistance and good creep-rupture strength at moderate temperatures, considering their ferritic matrix that usually results in lower creep resistance than austenitic steels. These steels showed brittleness and sample-to-sample variability in ductility. The low ductility might be due to the macro segregation during solidification or the significant grain growth during the solution heat treatments. We believe there is no inherent brittleness based on the chemistry of the steels. The creep-rupture performance of the steels is comparable to the 9Cr steels. Due to their ferritic matrix, the new Chi-phase strengthened ferritic steels may not be suited for the 760 °C AUSC applications, but they are very good candidates for intermediate temperature applications due to their outstanding oxidation resistance and high strength. Further study is required to find the source of low and highly variable ductility. We believe the compositions of the Chi-phase strengthened steels are not inherently brittle. The Chi-phase strengthened ferritic steels may also be excellent candidates for intermediate-temperature and room-temperature cast stainless steels, thus we highly recommend further investigations. The two Mn-containing austenitic steels based on the Laves phase showed good ductility, excellent oxidation resistance (slightly inferior to the two ferritic steels) at high temperatures and moderate creep strength. The creep-strength of the two austenitic steels based on the Larson-Miller parameters is higher than that of the traditional 316 stainless steels, but lower than the alumina-forming alloys (AFAs) developed at Oak Ridge National Laboratories. We do not recommend high priority in further studying these compositions unless higher Cr alloys are required for hot-corrosion resistance.« less
Endo, Shunji; Nakagawa, Tomo; Konishi, Ken; Ikenaga, Masakazu; Ohta, Katsuya; Nakashima, Shinsuke; Matsumoto, Kenichi; Nishikawa, Kazuhiro; Ohmori, Takeshi; Yamada, Terumasa
2017-01-01
Endoscopic placement of self-expandable metallic stents is reportedly effective for gastric outlet obstructions due to advanced gastric cancer, and is less invasive than gastrojejunostomy. For patients who have good performance status, we administer chemotherapy after stent placement, although the safety and feasibility of this chemotherapy have not yet been discussed in full. Between 2011 and 2015, 15 patients at our institution underwent endoscopic gastroduodenal stent placement for gastric outlet obstruction due to gastric cancer. Eleven of these patients were administered chemotherapy after stent placement. In our case series, we did not observe any specific adverse event caused by stent placement plus chemotherapy. Adverse events after chemotherapy included anemia of CTCAE Grade 3 in 7 patients. Stent-in-stent placement was needed in 2 patients. Neither stent migration nor perforation was observed. Therefore, chemotherapy after stent placement for gastric outlet obstruction due to gastric cancer was considered safe and feasible. Stent placement is useful not only as palliative care for patients with terminal-stage disease, but also as one of the multimodal therapeutic strategies for gastric cancer.
NASA Astrophysics Data System (ADS)
Penasa, Mauro; Colombo, Enrico; Giolfo, Mauro
1994-09-01
Due to the good performance shown by laser welded joints, to the quality and repeatability achievable by this welding technique and to its high process productivity, a feature inherent to the laser technology which, together with its high flexibility, allows different operations to be performed by a single source, consistent savings in a production line may be obtained. Therefore laser welding techniques may be of high relevance for industrial applications, provided that a sufficient attention is paid to avoiding a low utilization time to the operating laser source. The paper describes a feasibility study for the integration of a laser source as an automatic unit for circumferential butt welding of tubes in production lines of pipe coils, just before the cold bending station. Using a 6 kW CO2 source, thickness ranging from 3.5 to 11.2 mm in carbon, low alloyed Cr-Mo and austenitic stainless steels, have been successfully welded. Cr-Mo steels require on line preheating treatment, which however can be achieved by laser defocused passes just before welding. The results of the preliminary qualification performed on laser welded joints of the involved topologies of product (materials, diameters and thicknesses) are described together with technological tests required for approval: laser circumferential butt welding of tubes has proven to be effective, with satisfactory and repeatable results and good joint performances. An exhaustive comparison with current welding techniques (TIG, MIG) is then carried out, along with a detailed analysis of the potential advantages and benefits which may be expected by using the laser welding technique, as well as with a first estimation of the investments and running costs. Since laser productivity is saturated only at a rough 35% during the year, an accurate analysis of other possible applications and of a possible lay out of a laser working cell integrated in the factory production lines is performed. Usually little attention is given to this problem and this is one of the causes of uncertainty when investments in a laser are planned. In most cases a source is devoted to a single application, even if effective working time is really low due to laser fast processing. Therefore potential benefits are substantially reduced to a minimum amount of what can be expected by this flexible technology.
Yeates, Peter; O'Neill, Paul; Mann, Karen; Eva, Kevin W
2012-12-05
Competency-based models of education require assessments to be based on individuals' capacity to perform, yet the nature of human judgment may fundamentally limit the extent to which such assessment is accurately possible. To determine whether recent observations of the Mini Clinical Evaluation Exercise (Mini-CEX) performance of postgraduate year 1 physicians influence raters' scores of subsequent performances, consistent with either anchoring bias (scores biased similar to previous experience) or contrast bias (scores biased away from previous experience). Internet-based randomized, blinded experiment using videos of Mini-CEX assessments of postgraduate year 1 trainees interviewing new internal medicine patients. Participants were 41 attending physicians from England and Wales experienced with the Mini-CEX, with 20 watching and scoring 3 good trainee performances and 21 watching and scoring 3 poor performances. All then watched and scored the same 3 borderline video performances. The study was completed between July and November 2011. The primary outcome was scores assigned to the borderline videos, using a 6-point Likert scale (anchors included: 1, well below expectations; 3, borderline; 6, well above expectations). Associations were tested in a multivariable analysis that included participants' sex, years of practice, and the stringency index (within-group z score of initial 3 ratings). The mean rating scores assigned by physicians who viewed borderline video performances following exposure to good performances was 2.7 (95% CI, 2.4-3.0) vs 3.4 (95% CI, 3.1-3.7) following exposure to poor performances (difference of 0.67 [95% CI, 0.28-1.07]; P = .001). Borderline videos were categorized as consistent with failing scores in 33 of 60 assessments (55%) in those exposed to good performances and in 15 of 63 assessments (24%) in those exposed to poor performances (P < .001). They were categorized as consistent with passing scores in 5 of 60 assessments (8.3%) in those exposed to good performances compared with 25 of 63 assessments (39.5%) in those exposed to poor performances (P < .001). Sex and years of attending practice were not associated with scores. The priming condition (good vs poor performances) and the stringency index jointly accounted for 45% of the observed variation in raters' scores for the borderline videos (P < .001). In an experimental setting, attending physicians exposed to videos of good medical trainee performances rated subsequent borderline performances lower than those who had been exposed to poor performances, consistent with a contrast bias.
NASA Astrophysics Data System (ADS)
Durgalakshmi, D.; Ajay Rakkesh, R.; Bhargavi Ram, T.; Balakumar, S.
2017-07-01
Diabetes mellitus is the most common endocrine disorder due to carbohydrate metabolism. Also, zinc and its supplements have been used in Indian traditional medicines for treating urinary tract infections. In this work, an attempt has been made to compare the properties of ‘Yashadha Bhasma’ a traditional ayurvedic ZnO supplement for diabetic treatment with the laboratory-synthesized ZnO nanoparticles. The nano-sized ZnO particles are synthesized using co-precipitation method and calcined at 400 °C for further purification. Confirmation of ZnO and presence of Ca and K elements additional to Zn in Yashadha Bhasma is confirmed from XPS. The morphology of ZnO is found to be spherical with average diameter of 15 nm. TEM results show that ZnO rods of Yashadha Bhasma are porous and non-uniform. Glucose degradation studies revealed good performance with ZnO nanoparticles with 80% degradation occurring within 15 min itself. Antibacterial studies also performed well establishing efficacy of ZnO nanoparticles against both gram-positive and gram-negative bacterial strains, thereby establishing suitable material for treating diabetes mellitus and also curing bacterial wound infections arising due to diabetes mellitus.
Shock timing measurements and analysis in deuterium-tritium-ice layered capsule implosions on NIF
NASA Astrophysics Data System (ADS)
Robey, H. F.; Celliers, P. M.; Moody, J. D.; Sater, J.; Parham, T.; Kozioziemski, B.; Dylla-Spears, R.; Ross, J. S.; LePape, S.; Ralph, J. E.; Hohenberger, M.; Dewald, E. L.; Berzak Hopkins, L.; Kroll, J. J.; Yoxall, B. E.; Hamza, A. V.; Boehly, T. R.; Nikroo, A.; Landen, O. L.; Edwards, M. J.
2014-02-01
Recent advances in shock timing experiments and analysis techniques now enable shock measurements to be performed in cryogenic deuterium-tritium (DT) ice layered capsule implosions on the National Ignition Facility (NIF). Previous measurements of shock timing in inertial confinement fusion implosions [Boehly et al., Phys. Rev. Lett. 106, 195005 (2011); Robey et al., Phys. Rev. Lett. 108, 215004 (2012)] were performed in surrogate targets, where the solid DT ice shell and central DT gas were replaced with a continuous liquid deuterium (D2) fill. These previous experiments pose two surrogacy issues: a material surrogacy due to the difference of species (D2 vs. DT) and densities of the materials used and a geometric surrogacy due to presence of an additional interface (ice/gas) previously absent in the liquid-filled targets. This report presents experimental data and a new analysis method for validating the assumptions underlying this surrogate technique. Comparison of the data with simulation shows good agreement for the timing of the first three shocks, but reveals a considerable discrepancy in the timing of the 4th shock in DT ice layered implosions. Electron preheat is examined as a potential cause of the observed discrepancy in the 4th shock timing.
Schnerr, Roald S; Jansen, Jacobus F A; Uludag, Kamil; Hofman, Paul A M; Wildberger, Joachim E; van Oostenbrugge, Robert J; Backes, Walter H
2017-01-01
Characterization of flow properties in cerebral arteries with 1.5 and 3 Tesla MRI is usually limited to large cerebral arteries and difficult to evaluate in the small perforating arteries due to insufficient spatial resolution. In this study, we assessed the feasibility to measure blood flow waveforms in the small lenticulostriate arteries with 7 Tesla velocity-sensitive MRI. The middle cerebral artery was included as reference. Imaging was performed in five young and five old healthy volunteers. Flow was calculated by integrating time-varying velocity values over the vascular cross-section. MRI acquisitions were performed twice in each subject to determine reproducibility. From the flow waveforms, the pulsatility index and damping factor were deduced. Reproducibility values, in terms of the intraclass correlation coefficients, were found to be good to excellent. Measured pulsatility index of the lenticulostriate arteries significantly increased and damping factor significantly decreased with age. In conclusion, we demonstrate that blood flow through the lenticostriate arteries can be precisely measured using 7 Tesla MRI and reveal effects of arterial stiffness due to aging. These findings hold promise to provide relevant insights into the pathologies involving perforating cerebral arteries.
NASA Technical Reports Server (NTRS)
Stone, Bradley M.
1998-01-01
The Astrochemistry Group at NASA Ames Research Center is interested in the identification of large organic molecules in the interstellar medium Many smaller organic species (e.g. hydrocarbons, alcohols, etc.) have been previously identified by their radiofrequency signature due to molecular rotations. However, this becomes increasingly difficult to observe as the size of the molecule increases. Our group in interested in the identification of the carriers of the Diffuse Interstellar Bands (absorption features observed throughout the visible and near-infrared in the spectra of stars, due to species in the interstellar medium). Polycyclic Aromatic Hydrocarbons (PAHs) and related molecules are thought to be good candidates for these carriers. Laboratory experiments am performed at Ames to simulate the interstellar environment, and to compare spectra obtained from molecules in the laboratory to those derived astronomically. We are also interested in PAHs with respect to their possible connection to the UIR (Unidentified infrared) and ERE (Extended Red Emission) bands - emission features found to emanate from particular regions of our galaxy (e.g. Orion nebula, Red Rectangle, etc.). An old, "tried and proven spectroscopic technique, matrix isolation spectroscopy creates molecular conditions ideal for performing laboratory astrophysics.
Theoretical studies on lattice-oriented growth of single-walled carbon nanotubes on sapphire
NASA Astrophysics Data System (ADS)
Li, Zhengwei; Meng, Xianhong; Xiao, Jianliang
2017-09-01
Due to their excellent mechanical and electrical properties, single-walled carbon nanotubes (SWNTs) can find broad applications in many areas, such as field-effect transistors, logic circuits, sensors and flexible electronics. High-density, horizontally aligned arrays of SWNTs are essential for high performance electronics. Many experimental studies have demonstrated that chemical vapor deposition growth of nanotubes on crystalline substrates such as sapphire offers a promising route to achieve such dense, perfectly aligned arrays. In this work, a theoretical study is performed to quantitatively understand the van der Waals interactions between SWNTs and sapphire substrates. The energetically preferred alignment directions of SWNTs on A-, R- and M-planes and the random alignment on the C-plane predicted by this study are all in good agreement with experiments. It is also shown that smaller SWNTs have better alignment than larger SWNTs due to their stronger interaction with sapphire substrate. The strong vdW interactions along preferred alignment directions can be intuitively explained by the nanoscale ‘grooves’ formed by atomic lattice structures on the surface of sapphire. This study provides important insights to the controlled growth of nanotubes and potentially other nanomaterials.
Melillo, Paolo; Jovic, Alan; De Luca, Nicola; Pecchia, Leandro
2015-08-01
Accidental falls are a major problem of later life. Different technologies to predict falls have been investigated, but with limited success, mainly because of low specificity due to a high false positive rate. This Letter presents an automatic classifier based on heart rate variability (HRV) analysis with the goal to identify fallers automatically. HRV was used in this study as it is considered a good estimator of autonomic nervous system (ANS) states, which are responsible, among other things, for human balance control. Nominal 24 h electrocardiogram recordings from 168 cardiac patients (age 72 ± 8 years, 60 female), of which 47 were fallers, were investigated. Linear and nonlinear HRV properties were analysed in 30 min excerpts. Different data mining approaches were adopted and their performances were compared with a subject-based receiver operating characteristic analysis. The best performance was achieved by a hybrid algorithm, RUSBoost, integrated with feature selection method based on principal component analysis, which achieved satisfactory specificity and accuracy (80 and 72%, respectively), but low sensitivity (51%). These results suggested that ANS states causing falls could be reliably detected, but also that not all the falls were due to ANS states.
Li, Zhenglong; Choi, Jae-Soon; Wang, Huamin; ...
2017-08-18
Low-temperature hydrogenation of carbonyl fractions can greatly improve the thermal stability of fast pyrolysis bio-oil which is crucial to achieve long-term operation of high-temperature upgrading reactors. The current state of the art, precious metals such as ruthenium, although highly effective in carbonyl hydrogenation, rapidly loses performance due to sulfur sensitivity. The present work showed that molybdenum carbides were active and sulfur-tolerant in low-temperature conversion carbonyl compounds. Furthermore, due to surface bifunctionality (presence of both metallic and acid sites), carbides catalyzed both C=O bond hydrogenation and C-C coupling reactions retaining most of carbon atoms in liquid products as more stable andmore » higher molecular weight oligomeric compounds while consuming less hydrogen than ruthenium. The carbides proved to be resistant to other deactivation mechanisms including hydrothermal aging, oxidation, coking and leaching. These properties enabled carbides to achieve and maintain good catalytic performance in both aqueous-phase furfural conversion and real bio-oil stabilization with sulfur present. This finding strongly suggests that molybdenum carbides can provide a catalyst solution necessary for the development of commercially viable bio-oil stabilization technology.« less
NASA Astrophysics Data System (ADS)
Park, Byung Hyun; Choi, Gyeong Man
2015-10-01
Perovskite oxides have potential for use as alternative anode materials in solid oxide fuel cells (SOFCs) due to stability in anode atmosphere; donor-doped SrTiO3 (e.g., La0.2Sr0.8TiO3-δ) is a good candidate for this purpose. Electro-catalytic nanoparticles can be produced in oxide anodes by the ex-solution method, e.g., by incorporating Ni into a perovskite oxide in air, then reducing the oxide in H2 atmosphere. In this study, we varied the temperature (1100, 1250 °C) and atmosphere (air, H2) of La0.2Sr0.8Ti0.9Ni0.1O3-δ (LSTN) anode firing to control the degree of Ni ex-solution and microstructure. LSTN fired at 1250 °C in H2 showed the best anodic performance for scandia-stabilized zirconia (ScSZ) electrolyte-supported cells in H2 and CH4 fuels due to the favorable microstructure and Ni ex-solution.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Li, Zhenglong; Choi, Jae-Soon; Wang, Huamin
Low-temperature hydrogenation of carbonyl fractions can greatly improve the thermal stability of fast pyrolysis bio-oil which is crucial to achieve long-term operation of high-temperature upgrading reactors. The current state of the art, precious metals such as ruthenium, although highly effective in carbonyl hydrogenation, rapidly loses performance due to sulfur sensitivity. The present work showed that molybdenum carbides were active and sulfur-tolerant in low-temperature conversion carbonyl compounds. Furthermore, due to surface bifunctionality (presence of both metallic and acid sites), carbides catalyzed both C=O bond hydrogenation and C-C coupling reactions retaining most of carbon atoms in liquid products as more stable andmore » higher molecular weight oligomeric compounds while consuming less hydrogen than ruthenium. The carbides proved to be resistant to other deactivation mechanisms including hydrothermal aging, oxidation, coking and leaching. These properties enabled carbides to achieve and maintain good catalytic performance in both aqueous-phase furfural conversion and real bio-oil stabilization with sulfur present. This finding strongly suggests that molybdenum carbides can provide a catalyst solution necessary for the development of commercially viable bio-oil stabilization technology.« less
The Future of HPT Depends on Whether Practitioners Focus on Foundations or Fads
ERIC Educational Resources Information Center
Brethower, Dale M.
2012-01-01
The future of human performance technology (HPT) will be bright or dismal depending on how well HPT practitioners focus on careful and practical answers to three pivotal questions: What is good practice in human performance technology? What are the differences between good practice and bad? What are the connections between good research and…
Acting, Accidents and Performativity: Challenging the Hegemonic Good Student in Secondary Schools
ERIC Educational Resources Information Center
Thompson, Greg
2010-01-01
Current educational practice tends to ascribe a limiting vision of the good student as one who is well behaved, performs well in assessments and demonstrates values in keeping with dominant expectations. This paper argues that this vision of the good student is antithetical to the lived experience of students as they negotiate their positionality…
High-Performance Java Codes for Computational Fluid Dynamics
NASA Technical Reports Server (NTRS)
Riley, Christopher; Chatterjee, Siddhartha; Biswas, Rupak; Biegel, Bryan (Technical Monitor)
2001-01-01
The computational science community is reluctant to write large-scale computationally -intensive applications in Java due to concerns over Java's poor performance, despite the claimed software engineering advantages of its object-oriented features. Naive Java implementations of numerical algorithms can perform poorly compared to corresponding Fortran or C implementations. To achieve high performance, Java applications must be designed with good performance as a primary goal. This paper presents the object-oriented design and implementation of two real-world applications from the field of Computational Fluid Dynamics (CFD): a finite-volume fluid flow solver (LAURA, from NASA Langley Research Center), and an unstructured mesh adaptation algorithm (2D_TAG, from NASA Ames Research Center). This work builds on our previous experience with the design of high-performance numerical libraries in Java. We examine the performance of the applications using the currently available Java infrastructure and show that the Java version of the flow solver LAURA performs almost within a factor of 2 of the original procedural version. Our Java version of the mesh adaptation algorithm 2D_TAG performs within a factor of 1.5 of its original procedural version on certain platforms. Our results demonstrate that object-oriented software design principles are not necessarily inimical to high performance.
Brain structure correlates of component reading processes: implications for reading disability.
Phinney, Erin; Pennington, Bruce F; Olson, Richard; Filley, Christopher M; Filipek, Pauline A
2007-08-01
Brain structures implicated in developmental dyslexia (reading disability - RD) vary greatly across structural magnetic resonance imaging (MRI) studies due to methodological differences regarding the definition of RD and the exact measurements of a specific brain structure. The current study attempts to resolve some of those methodological concerns by examining brain volume as it relates to components of proposed RD subtypes. We performed individual regression analyses on total cerebral volume, neocortical volume, subcortical volume, 9 neo-cortical structures and 2 sub-cortical structures. These analyses used three dimensions of reading, phonemic ability (PA), orthographic ability, and rapid naming (RN) ability, while accounting for total cerebral volume, age, and performance IQ (PIQ). Primary analyses included membership to a group (poor reader vs. good reader) in the analysis. The result was a significant interaction between PA and reading ability as it predicts total cerebral volume. Analyses revealed that poor readers lacked a relationship between PA and brain size, but that good readers had a significant positive relationship. This pattern of interaction was not present for the other two reading component factors. These findings bring into question the general belief that individuals with RD are at the low end of a reading ability distribution and do not have a unique disorder. Additional analyses revealed only a few significant relationships between brain size and task performance, most notably a positive correlation between orthographic ability and the angular gyrus (AG), as well as a negative correlation between RN ability and the parietal operculum (PO).
Salden, O A E; van Everdingen, W M; Spee, R; Doevendans, P A; Cramer, M J
2018-03-27
Stress echocardiography (SE) has recently regained momentum as an important diagnostic tool for the assessment of both ischemic and non-ischemic heart disease. Performing SE during physical exercise is challenging due to a suboptimal patient position and vigorous movements of the patient's chest. This hampers a stable ultrasound position and reduces the diagnostic performance of SE. A stable ultrasound probe position would facilitate producing high quality images during continuous measurements. With Probefix (Usono, Eindhoven, The Netherlands), a newly developed tool to fixate the ultrasound probe to the patient's chest, stabilization of the probe during physical exercise is possible. The technique of SE with the Probefix and its' feasibility are evaluated in a small pilot study. Probefix fixates the ultrasound probe to the patient's chest, using two chest straps and a fixation device. The ultrasound probe position and angle may be altered with a relative high degree of freedom. We tested the Probefix for continuous echocardiographic imaging in 12 study subjects during supine and upright ergometer stress tests. One patient was unable to perform exercise and in two study subjects good quality images were not achieved. In the other patients (82%) a stable probe position was obtained, with subsequent good quality echocardiographic images during SE. We have demonstrated the feasibility of the Probefix support during ergometer tests in supine and upright positions and conclude that this external fixator may facilitate continuous monitoring of cardiac function in a group of patients.
Garcia-Ruiz, Andres; Pastor-Graells, Juan; Martins, Hugo F; Tow, Kenny Hey; Thévenaz, Luc; Martin-Lopez, Sonia; Gonzalez-Herraez, Miguel
2017-02-06
Chemical sensing using optical fibers is often challenging, as it is generally difficult to achieve strong interaction between the guided light and the analyte at the wavelength of interest for performing the detection. Despite this difficulty, many schemes exist (and can be found in the literature) for point chemical fiber sensors. However, the challenge increases even further when it comes to performing fully distributed chemical sensing. In this case, the optical signal which interacts with the analyte is typically also the signal that has to travel to and from the interrogator: for a good sensitivity, the light should interact strongly with the analyte, leading inevitably to an increased loss and a reduced range. Few works in the literature actually provide demonstrations of truly distributed chemical sensing and, although there have been several attempts to realize these sensors (e.g. based on special fiber coatings), the vast majority of these attempts has failed to reach widespread use due to several reasons, among them: lack of sensitivity or selectivity, lack of range or resolution, cross sensitivity to temperature or strain, or need to work at specific wavelengths where fiber instrumentation becomes extremely expensive or unavailable. In this work we provide a preliminary demonstration of the possibility of achieving distributed detection of gas presence with spectroscopic selectivity, high spatial resolution, potential for long range measurements and feasibility of having most of the interrogator system working at conventional telecom wavelengths. For a full exploitation of this concept, new fibers (or more likely, fiber bundles) should be developed capable of guiding specific wavelengths in the IR (corresponding to gas absorption wavelengths) with good overlap with the analyte while also having a solid core with good transmission behavior at 1.55 μm, and good thermal coupling between the two guiding structures.
Boretzki, Johanna; Wolf, Eva; Wiese, Carmen; Noe, Sebastian; Balogh, Annamaria; Meurer, Anja; Krznaric, Ivanka; Zink, Alexander; Lersch, Christian; Spinner, Christoph D
2017-01-01
Reasons for and frequency of nonadherence to antiretroviral therapy (ART) may have changed due to pharmacological improvements. In addition, the importance of known non-pharmacologic reasons for nonadherence is unclear. We performed a cross-sectional, noninterventional, multicenter study to identify current reasons for nonadherence. Patients were categorized by physicians into the following adherence groups: good, unstable, or poor adherence. Co-variables of interest included age, sex, time since HIV diagnosis, ART duration, current ART regimen, HIV transmission route, comorbidity, HIV-1 RNA viral load (VL), and CD4 cell count. Patients self-reported the number of missed doses and provided their specific reasons for nonadherent behavior. Statistical analyses were performed using Fisher's extended exact test, Kruskal-Wallis test, and logistic regression models. Our study assessed 215 participants with good (n=162), unstable (n=36), and poor adherence (n=17). Compared to patients with good adherence, patients with unstable and poor adherence reported more often to have missed at least one dose during the last week (good 11% vs unstable 47% vs poor 63%, p <0.001). Physicians' adherence assessment was concordant with patients' self-reports of missed doses during the last week (no vs one or more) in 81% cases. Similarly, we found a strong association of physicians' assessment with viral suppression. Logistic regression analysis showed that "reduced adherence" - defined as unstable or poor - was significantly associated with patients <30 years old, intravenous drug use, history of acquired immune deficiency syndrome (AIDS), and psychiatric disorders ( p <0.05). Univariate analyses showed that specific reasons, such as questioning the efficacy/dosing of ART, HIV stigma, interactive toxicity beliefs regarding alcohol and/or party drugs, and dissatisfaction with regimen complexity, correlated with unstable or poor adherence ( p <0.05). Identification of factors associated with poor adherence helps in identifying patients with a higher risk for nonadherence. Reasons for nonadherence should be directly addressed in every patient, because they are common and constitute possible adherence intervention points.
Sleep-related attentional bias in poor versus good sleepers is independent of affective valence.
Barclay, Nicola L; Ellis, Jason G
2013-08-01
Contradictory evidence exists relating to the presence of an attention bias to sleep-related stimuli in poor sleepers/insomnia using the emotional Stroop task (EST). These inconsistencies may be due to methodological issues related to the affective valence of the sleep-related stimuli. Thus, individuals may attend differentially to sleep-related stimuli not because of their 'sleep' properties, but their negativity. The current study addresses this by controlling the affective valence of sleep-related words. A total of 107 participants [mean age = 33.22 years, standard deviation (SD) = 12.31 years; 61.7% female] were recruited during an evening event at the Newcastle Science Festival. Participants completed the Pittsburgh Sleep Quality Index (PSQI) and a computerized EST containing 20 non-affective sleep-related, 20 neutral and 20 negatively valenced threat words. Good and poor sleepers were categorized using the PSQI. There were no significant differences between groups on response latency to sleep-related words (t(105) = -0.30, P = 0.76). However, the interaction between good versus poor sleepers and word-type on response latency was significant (F(2,210) = 3.06, P < 0.05). Poor sleepers took longer to respond to sleep-related words (mean = 723.35, SD = 172.55) compared to threat words (mean = 694.63, SD = 162.17) than good sleepers (mean = 713.20, SD = 166.32; and mean = 716.65, SD = 181.14). The results demonstrate the presence of an attention bias towards sleep-related stimuli compared to threat stimuli in poor sleepers. Accordingly, poor sleepers may be consumed by stimuli relevant to their specific difficulties, as well as being more highly attuned to negative cues that signal anxious states. Thus, the present research suggests that there are two opposing forces at play: one which facilitates performance (non-specific threats) and one which hinders performance (personally relevant threats). © 2013 European Sleep Research Society.
Runaway sexual selection leads to good genes.
Chandler, Christopher H; Ofria, Charles; Dworkin, Ian
2013-01-01
Mate choice and sexual displays are widespread in nature, but their evolutionary benefits remain controversial. Theory predicts these traits can be favored by runaway sexual selection, in which preference and display reinforce one another due to genetic correlation; or by good genes benefits, in which mate choice is advantageous because extreme displays indicate a well-adapted genotype. However, these hypotheses are not mutually exclusive, and the adaptive benefits underlying mate choice can themselves evolve. In particular, examining how and why sexual displays become indicators of good genes is challenging in natural systems. Here, we use experimental evolution in "digital organisms" to demonstrate the origins of condition-dependent indicator displays following their spread due to a runaway process. Surprisingly, handicap-like costs are not necessary for displays to become indicators of male viability. Instead, a pleiotropic genetic architecture underlies both displays and viability. Runaway sexual selection and good genes benefits should thus be viewed as interacting mechanisms that reinforce one another. © 2012 The Author(s). Evolution© 2012 The Society for the Study of Evolution.
Stimulating Contributions to Public Goods through Information Feedback: Some Experimental Results
Janssen, Marco A.; Lee, Allen; Sundaram, Hari
2016-01-01
In traditional public good experiments participants receive an endowment from the experimenter that can be invested in a public good or kept in a private account. In this paper we present an experimental environment where participants can invest time during five days to contribute to a public good. Participants can make contributions to a linear public good by logging into a web application and performing virtual actions. We compared four treatments, with different group sizes and information of (relative) performance of other groups. We find that information feedback about performance of other groups has a small positive effect if we control for various attributes of the groups. Moreover, we find a significant effect of the contributions of others in the group in the previous day on the number of points earned in the current day. Our results confirm that people participate more when participants in their group participate more, and are influenced by information about the relative performance of other groups. PMID:27459070
Wang, Jiamian; Song, Jie; Wang, Xiuyun; Wu, Shuo; Zhao, Yanqiu; Luo, Pinchen; Meng, Changgong
2016-12-01
A label-free ratiometric fluorescence aptasensor has been developed for the rapid and sensitive detection of cocaine in complex biofluids. The fluorescent aptasensor is composed of a non-labeled GC-38 cocaine aptamer which serves as a basic sensing unit and two fluorophores, 2-amino-5,6,7-trimethyl-1,8-naphthyridine (ATMND) and SYBR Green I (SGI) which serves as a signal reporter and a build-in reference, respectively. The detection principle is based on a specific cocaine mediated ATMND displacement reaction and the corresponding change in the fluorescence ratio of ATMND to SGI. Due to the high affinity of the non-labeled aptamer, the good precision originated from the ratiometric method, and the good fluorescence quantum yield of the fluorophore, the aptasensor shows good analytical performance with respect to cocaine detection. Under optimal conditions, the aptasensor shows a linear range of 0.10-10μM and a low limit of detection of 56nM, with a fast response of 20s. The low limit of detection is comparable to most of the fluorescent aptasensors with signal amplification strategies and much lower than all of the unamplified cocaine aptasensors. Practical sample analysis in a series of complex biofluids, including urine, saliva and serum, also indicates the good precision, stability, and high sensitivity of the aptasensor, which may have great potential for the point-of-care screening of cocaine in complex biofluids. Copyright © 2016 Elsevier B.V. All rights reserved.
Haddad, B; Konan, S; Haddad, F S
2014-01-01
We have reviewed the current literature to compare the results of surgery aimed to repair or debride a damaged acetabular labrum. We identified 28 studies to be included in the review containing a total of 1631 hips in 1609 patients. Of these studies 12 reported a mean rate of good results of 82% (from 67% to 100%) for labral debridement. Of the 16 studies that reported a combination of debridement and re-attachment, five reported a comparative outcome for the two methods, four reported better results with re-attachment and one study did not find any significant difference in outcomes. Due to the heterogeneity of the studies it was not possible to perform a meta-analysis or draw accurate conclusions. Confounding factors in the studies include selection bias, use of historical controls and high rates of loss of follow-up. It seems logical to repair an unstable tear in a good quality labrum with good potential to heal in order potentially to preserve its physiological function. A degenerative labrum on the other hand may be the source of discomfort and its preservation may result in persistent pain and the added risk of failure of re-attachment. The results of the present study do not support routine refixation for all labral tears.
Stroebe, Wolfgang
2016-11-01
In this article, I address the paradox that university grade point averages have increased for decades, whereas the time students invest in their studies has decreased. I argue that one major contributor to this paradox is grading leniency, encouraged by the practice of university administrators to base important personnel decisions on student evaluations of teaching. Grading leniency creates strong incentives for instructors to teach in ways that would result in good student evaluations. Because many instructors believe that the average student prefers courses that are entertaining, require little work, and result in high grades, they feel under pressure to conform to those expectations. Evidence is presented that the positive association between student grades and their evaluation of teaching reflects a bias rather than teaching effectiveness. If good teaching evaluations reflected improved student learning due to effective teaching, they should be positively related to the grades received in subsequent courses that build on knowledge gained in the previous course. Findings that teaching evaluations of concurrent courses, though positively correlated with concurrent grades, are negatively related to student performance in subsequent courses are more consistent with the assumption that concurrent evaluations are the result of lenient grading rather than effective teaching. Policy implications are discussed. © The Author(s) 2016.
NASA Astrophysics Data System (ADS)
Rodríguez, L.; Ferrer, M.; Vargas, F.; Peña, G.
2017-12-01
A numerical simulation was performed with the software Jets et Poudres, the results let choose the parameters to deposit zirconia-alumina-ceria coatings of different composition on substrates of red clay, by thermal spraying with the oxyacetylene flame to obtain homogeneous coatings with good adhesion to the substrate. The effect of the projection distance (7, 10 and 12cm) between the substrate and the torch, the fusion percentage of particles and the K-Sommerfeld number was determined. This number is dimensionless and is affected by the projection distance and by the chemical composition of the particles. For a projection distance of 9cm, the fusion percentage of the particles varies between 83.8% and 100%, and the K-Sommerfeld number between 47.3 and 50 for the different compounds. This makes possible to obtain uniform coatings with good wettability, therefore, good adhesion to the substrate, while for the distance of 7cm the fusion percentage varies between 22% and 38%, due to the short time of the particles in the flame which causes low adhesion, when the projection distance is 12cm the particles do not have sufficient kinetic energy to reach the substrate and therefore the coating is not deposited.
Li, Xin; Zhang, Qiang; Zhao, Changsong; Sun, Sheng; Cai, Juan
2014-09-09
To observe the healing status of surgical incisions in human immunodeficiency virus (HIV)-positive patients with fractures and explore the factors related with poor wound healing, treatment and preventive measures. Retrospective analyses were performed for the clinical data of 61 HIV-positive patients with fractures. And the influencing factors, treatment and outcomes of poor wound healing were analyzed. Among them, the healing status was good (n = 50) and poor (n = 11). And the outcomes included redness (n = 10), oozing (n = 8), split (n = 3), infection (n = 2), hematoma (n = 1), fat liquefaction (n = 2) and delayed healing (n = 2). All healed well after treatment. There was no infection or death during the follow-up period. Compared with HIV-negative patients, it was not statistically significant in wound infection. However, poor healing rates were significantly different (P < 0.05). The risk factors included advanced age, low body mass index, low albumin, low hemoglobin, low total lymphocyte count, low CD4⁺ T lymphocyte count, high HIV infection clinical stage, long operative duration, emergency surgery and incision contamination. In HIV-positive patients with fractures, the healing of surgical incision is generally good. However few have poor wound healing due to multiple factors. If poor healing is identified early and handled timely and correctly, good healing ensues.
Schilcher, Jörg
2015-12-01
Healing of complete, atypical femoral fractures is thought to be impaired, but the evidence is weak and appears to be based on the delayed healing observed in patients with incomplete atypical fractures. Time until fracture healing is difficult to assess, therefore we compared the reoperation rates between women with complete atypical femoral fractures and common femoral shaft fractures. We searched the orthopaedic surgical registry in Östergötland County for patients with subtrochanteric and femoral shaft fractures (ICD-10 diagnosis codes S72.2, S72.3 and M84.3F) between January 1st 2007 and December 31st 2013. Out of 895 patients with surgically treated femoral shaft fractures, 511 were women 50 years of age or older. Among these we identified 24 women with atypical femoral shaft fractures, and 71 with common shaft fractures. Reoperations were performed in 6 and 5 patients, respectively, odds ratio 4.4 (95% CI 1.2 to 16.1). However, 5 reoperations in the atypical fracture group could not be ascribed to poor healing. In 3 patients the reoperation was due to a new fracture proximal to a standard intramedullary nail. In 2 patients the distal locking screws were removed due to callus formation that was deemed incomplete 5 months post-operatively. The one patient with poor healing showed faint callus formation at 5 months when the fracture was dynamised and callus remained sparse at 11 months. Among patients with common shaft fractures, 2 reoperations were performed to remove loose screws, 2 because of peri-implant fractures and 1 reoperation due to infection. Reoperation rates in patients with complete atypical femoral fractures are higher than in patients with common shaft fractures. The main reason for failure was peri-implant fragility fractures which might be prevented with the use of cephalomedullary nails at the index surgery. Fracture healing however, seems generally good. A watchful waiting approach is advocated in patients with fractures that appear to heal slowly. Copyright © 2015 Elsevier Ltd. All rights reserved.
The use of vision-based image quality metrics to predict low-light performance of camera phones
NASA Astrophysics Data System (ADS)
Hultgren, B.; Hertel, D.
2010-01-01
Small digital camera modules such as those in mobile phones have become ubiquitous. Their low-light performance is of utmost importance since a high percentage of images are made under low lighting conditions where image quality failure may occur due to blur, noise, and/or underexposure. These modes of image degradation are not mutually exclusive: they share common roots in the physics of the imager, the constraints of image processing, and the general trade-off situations in camera design. A comprehensive analysis of failure modes is needed in order to understand how their interactions affect overall image quality. Low-light performance is reported for DSLR, point-and-shoot, and mobile phone cameras. The measurements target blur, noise, and exposure error. Image sharpness is evaluated from three different physical measurements: static spatial frequency response, handheld motion blur, and statistical information loss due to image processing. Visual metrics for sharpness, graininess, and brightness are calculated from the physical measurements, and displayed as orthogonal image quality metrics to illustrate the relative magnitude of image quality degradation as a function of subject illumination. The impact of each of the three sharpness measurements on overall sharpness quality is displayed for different light levels. The power spectrum of the statistical information target is a good representation of natural scenes, thus providing a defined input signal for the measurement of power-spectrum based signal-to-noise ratio to characterize overall imaging performance.
Tu, Zhiming; Yang, Gongzheng; Song, Huawei; Wang, Chengxin
2017-01-11
Due to its high theoretical capacity (978 mA h g -1 ), natural abundance, environmental friendliness, and low cost, zinc oxide is regarded as one of the most promising anode materials for lithium-ion batteries (LIBs). A lot of research has been done in the past few years on this topic. However, hardly any research on amorphous ZnO for LIB anodes has been reported despite the fact that the amorphous type could have superior electrochemical performance due to its isotropic nature, abundant active sites, better buffer effect, and different electrochemical reaction details. In this work, we develop a simple route to prepare an amorphous ZnO quantum dot (QDs)/mesoporous carbon bubble composite. The composite consists of two parts: mesoporous carbon bubbles as a flexible skeleton and monodisperse amorphous zinc oxide QDs (smaller than 3 nm) encapsulated in an amorphous carbon matrix as a continuous coating tightly anchored on the surface of mesoporous carbon bubbles. With the benefits of abundant active sites, amorphous nature, high specific surface area, buffer effect, hierarchical pores, stable interconnected conductive network, and multidimensional electron transport pathways, the amorphous ZnO QD/mesoporous carbon bubble composite delivers a high reversible capacity of nearly 930 mA h g -1 (at current density of 100 mA g -1 ) with almost 90% retention for 85 cycles and possesses a good rate performance. This work opens the possibility to fabricate high-performance electrode materials for LIBs, especially for amorphous metal oxide-based materials.
Experimental and analytical study of close-coupled ventral nozzles for ASTOVL aircraft
NASA Technical Reports Server (NTRS)
Mcardle, Jack G.; Smith, C. Frederic
1990-01-01
Flow in a generic ventral nozzle system was studied experimentally and analytically with a block version of the PARC3D computational fluid dynamics program (a full Navier-Stokes equation solver) in order to evaluate the program's ability to predict system performance and internal flow patterns. For the experimental work a one-third-size model tailpipe with a single large rectangular ventral nozzle mounted normal to the tailpipe axis was tested with unheated air at steady-state pressure ratios up to 4.0. The end of the tailpipe was closed to simulate a blocked exhaust nozzle. Measurements showed about 5 1/2 percent flow-turning loss, reasonable nozzle performance coefficients, and a significant aftward axial component of thrust due to flow turning loss, reasonable nozzle performance coefficients, and a significant aftward axial component of thrust due to flow turning more than 90 deg. Flow behavior into and through the ventral duct is discussed and illustrated with paint streak flow visualization photographs. For the analytical work the same ventral system configuration was modeled with two computational grids to evaluate the effect of grid density. Both grids gave good results. The finer-grid solution produced more detailed flow patterns and predicted performance parameters, such as thrust and discharge coefficient, within 1 percent of the measured values. PARC3D flow visualization images are shown for comparison with the paint streak photographs. Modeling and computational issues encountered in the analytical work are discussed.
Efficient Computing Budget Allocation for Finding Simplest Good Designs
Jia, Qing-Shan; Zhou, Enlu; Chen, Chun-Hung
2012-01-01
In many applications some designs are easier to implement, require less training data and shorter training time, and consume less storage than the others. Such designs are called simple designs, and are usually preferred over complex ones when they all have good performance. Despite the abundant existing studies on how to find good designs in simulation-based optimization (SBO), there exist few studies on finding simplest good designs. We consider this important problem in this paper, and make the following contributions. First, we provide lower bounds for the probabilities of correctly selecting the m simplest designs with top performance, and selecting the best m such simplest good designs, respectively. Second, we develop two efficient computing budget allocation methods to find m simplest good designs and to find the best m such designs, respectively; and show their asymptotic optimalities. Third, we compare the performance of the two methods with equal allocations over 6 academic examples and a smoke detection problem in wireless sensor networks. We hope that this work brings insight to finding the simplest good designs in general. PMID:23687404
2014-04-01
successes against the Roman army, Plutarch focused on Sertorius’ ability to bring good order and discipline to the seemingly barbaric tribes of the...Roman frontier.161 Plutarch noted that after the campaigns against Rome, Sertorius was “highly honored for his introducing discipline and good order...Sertorius’ ability to achieve good order and discipline within his troops, Plutarch did not mention discipline or fear; instead, he noted that Sertorius
Leufkens, T R M; Ramaekers, J G; de Weerd, A W; Riedel, W J; Vermeeren, A
2014-07-01
Many older adults report sleep problems and use of hypnotics. Several studies have shown that hypnotics can have acute adverse effects on driving the next morning. It is unclear however whether driving of chronic hypnotic users is impaired. Therapeutic effects on insomnia and development of tolerance may reduce the residual effects on driving. The present study aimed to compare actual driving performance and driving-related skills of chronic hypnotic users to good sleepers. To determine whether insomnia itself affects driving performance, driving and driving-related skills were compared between insomnia patients who do not or infrequently use hypnotics and good sleepers. Twenty-two frequent users of hypnotics (using hypnotics ≥ 4 nights per week for more than 3 months), 20 infrequent users (using hypnotics ≤ 3 nights per week), and 21 healthy, age-matched controls participated in this study. On the night before testing, all subjects were hospitalized for an 8-h sleep recorded by polysomnography. Frequent hypnotic users used their regular medication at bedtime (2330 hours), while infrequent users and controls received no medication. Cognitive performance (word learning, digit span, tracking, divided attention, vigilance, and inhibitory control) was assessed 8.5 h and driving performance between 10 and 11 h after bedtime and dosing. Polysomnographic recordings did not significantly differ between the groups, but the insomnia patients, treated or untreated, still reported subjective sleep complaints. Results show no differences in driving performance and driving-related skills between both groups of insomnia patients and controls. Driving performance in chronic users of hypnotics and untreated insomnia patients is not impaired. For chronic users, this may be due to prescription of relatively safe drugs and low doses. For untreated insomniacs, this corroborates previous findings showing an absence of neuropsychological deficits in this group of patients.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Liang, Kun; Marcus, Kyle; Yang, Zhenzhong
In this work, a freestanding NiFe oxyfluoride (NiFeOF) holey film was prepared by electrochemical deposition and anodic treatments. With the combination of good electrical conductivity and holey structure, the NiFeOF holey film offers superior electrochemical performance, due to the following reasons: (i) The residual metal alloy framework can be used as the current collector to improve electrode conductivity. Moreover, the as-prepared freestanding NiFeOF holey film can be used as a supercapacitor electrode without reliance on binders and other additives. The residual metal alloy framework and binder-free electrode effectively reduces electrode resistance, thus improving electron transport. (ii) The highly interconnected holeymore » structure and hierarchical pore distribution provides a high specific surface area to improve electron transport, enhancing rapid ion transport and mitigating diffusion limitations throughout the holey film. (iii) The excellent mechanical characteristics facilitate flexibility and cyclability related performance. Additionally, the NiFeOF holey film presents exceptional electrochemical performance, showing that it is a promising alternative for small/micro-size electronic devices.« less
Leone, Alessia; Ferrari, Pier Francesco; Palagi, Elisabetta
2014-01-01
Here, we tested hypotheses about the potential functions of yawning based on its intensity and social contexts. Due to their spectrum intensity of yawns (covered teeth/YW1; uncovered teeth/YW2; uncovered gums/YW3), geladas are a good model species for this purpose. We suggest that yawns of different intensity can bear different information according to the performer, the context and the behavioural pattern temporally associated to the yawn event. YW3, mainly performed by high ranking males during periods of high social tension, was frequently associated with an auditory component and often accompanied by scratching (a measure of anxiety). YW1 and YW2, preferentially performed by females, were frequently associated to lip smacking, an affiliative display. In conclusion, even though a clear-cut functional distinction of geladas' yawn intensity is difficult, YW1 and YW2 seem to be more linked to affiliative social interactions; whereas, YW3 seems to be more linked to agonistic and tension situations. PMID:24500137
Li, Weimin; Wang, Xiaobo
2015-01-01
Waste cooking oil (WCO) was chemically modified via epoxidation using H2O2 followed by transesterification with methanol and branched alcohols (isooctanol, isotridecanol and isooctadecanol) to produce bio-lubricants with improved oxidative stability and low temperature properties. Physicochemical properties of synthesized bio-lubricants such as pour point (PP), cloud point (CP), viscosity, viscosity index (VI), oxidative stability, and corrosion resistant property were determined according to standard methods. The synthesized bio-lubricants showed improved low temperature flow performances compared with WCO, which can be attributing to the introduction of branched chains in their molecular structures. What's more, the oxidation stability of the WCO showed more than 10 folds improvement due to the elimination of -C=C-bonds in the WCO molecule. Tribological performances of these bio-lubricants were also investigated using four-ball friction and wear tester. Experimental results showed that derivatives of WCO exhibited favorable physicochemical properties and tribological performances which making them good candidates in formulating eco-friendly lubricants.
NASA Astrophysics Data System (ADS)
Kurzeck, Bernhard; Heckmann, Andreas; Wesseler, Christoph; Rapp, Matthias
2014-05-01
Future high-speed trains are the main focus of the DLR research project Next Generation Train. One central point of the research activities is the development of mechatronic track guidance for the two-axle intermediate wagons with steerable, individually powered, independently rotating wheels. The traction motors hereby fulfil two functions; they concurrently are traction drives and steering actuators. In this paper, the influence of the track properties - line layout and track irregularities - on the performance requirements for the guidance actuator is investigated using multi-body models in SIMPACK®. In order to compromise on the design conflict between low wheel wear and low steering torque, the control parameters of the mechatronic track guidance are optimised using the DLR in-house software MOPS. Besides the track irregularities especially the increasing inclination at transition curves defines high actuator requirements due to gyroscopic effects at high speed. After introducing a limiter for the actuating variables into the control system, a good performance is achieved.
Evanoff, Kara; Benson, Jim; Schauer, Mark; Kovalenko, Igor; Lashmore, David; Ready, W Jud; Yushin, Gleb
2012-11-27
Materials that can perform simultaneous functions allow for reductions in the total system mass and volume. Developing technologies to produce flexible batteries with good performance in combination with high specific strength is strongly desired for weight- and power-sensitive applications such as unmanned or aerospace vehicles, high-performance ground vehicles, robotics, and smart textiles. State of the art battery electrode fabrication techniques are not conducive to the development of multifunctional materials due to their inherently low strength and conductivities. Here, we present a scalable method utilizing carbon nanotube (CNT) nonwoven fabric-based technology to develop flexible, electrochemically stable (∼494 mAh·g(-1) for 150 cycles) battery anodes that can be produced on an industrial scale and demonstrate specific strength higher than that of titanium, copper, and even a structural steel. Similar methods can be utilized for the formation of various cathode and anode composites with tunable strength and energy and power densities.
Beyond the Required LISA Free-Fall Performance: New LISA Pathfinder Results down to 20 μ Hz
NASA Astrophysics Data System (ADS)
Armano, M.; Audley, H.; Baird, J.; Binetruy, P.; Born, M.; Bortoluzzi, D.; Castelli, E.; Cavalleri, A.; Cesarini, A.; Cruise, A. M.; Danzmann, K.; de Deus Silva, M.; Diepholz, I.; Dixon, G.; Dolesi, R.; Ferraioli, L.; Ferroni, V.; Fitzsimons, E. D.; Freschi, M.; Gesa, L.; Gibert, F.; Giardini, D.; Giusteri, R.; Grimani, C.; Grzymisch, J.; Harrison, I.; Heinzel, G.; Hewitson, M.; Hollington, D.; Hoyland, D.; Hueller, M.; Inchauspé, H.; Jennrich, O.; Jetzer, P.; Karnesis, N.; Kaune, B.; Korsakova, N.; Killow, C. J.; Lobo, J. A.; Lloro, I.; Liu, L.; López-Zaragoza, J. P.; Maarschalkerweerd, R.; Mance, D.; Meshksar, N.; Martín, V.; Martin-Polo, L.; Martino, J.; Martin-Porqueras, F.; Mateos, I.; McNamara, P. W.; Mendes, J.; Mendes, L.; Nofrarias, M.; Paczkowski, S.; Perreur-Lloyd, M.; Petiteau, A.; Pivato, P.; Plagnol, E.; Ramos-Castro, J.; Reiche, J.; Robertson, D. I.; Rivas, F.; Russano, G.; Slutsky, J.; Sopuerta, C. F.; Sumner, T.; Texier, D.; Thorpe, J. I.; Vetrugno, D.; Vitale, S.; Wanner, G.; Ward, H.; Wass, P. J.; Weber, W. J.; Wissel, L.; Wittchen, A.; Zweifel, P.
2018-02-01
In the months since the publication of the first results, the noise performance of LISA Pathfinder has improved because of reduced Brownian noise due to the continued decrease in pressure around the test masses, from a better correction of noninertial effects, and from a better calibration of the electrostatic force actuation. In addition, the availability of numerous long noise measurement runs, during which no perturbation is purposely applied to the test masses, has allowed the measurement of noise with good statistics down to 20 μ Hz . The Letter presents the measured differential acceleration noise figure, which is at (1.74 ±0.01 ) fm s-2/√{Hz } above 2 mHz and (6 ±1 ) ×10 fm s-2/√{Hz } at 20 μ Hz , and discusses the physical sources for the measured noise. This performance provides an experimental benchmark demonstrating the ability to realize the low-frequency science potential of the LISA mission, recently selected by the European Space Agency.
Wan, Fang; Zhang, Linlin; Dai, Xi; Wang, Xinyu; Niu, Zhiqiang; Chen, Jun
2018-04-25
Rechargeable aqueous zinc-ion batteries are promising energy storage devices due to their high safety and low cost. However, they remain in their infancy because of the limited choice of positive electrodes with high capacity and satisfactory cycling performance. Furthermore, their energy storage mechanisms are not well established yet. Here we report a highly reversible zinc/sodium vanadate system, where sodium vanadate hydrate nanobelts serve as positive electrode and zinc sulfate aqueous solution with sodium sulfate additive is used as electrolyte. Different from conventional energy release/storage in zinc-ion batteries with only zinc-ion insertion/extraction, zinc/sodium vanadate hydrate batteries possess a simultaneous proton, and zinc-ion insertion/extraction process that is mainly responsible for their excellent performance, such as a high reversible capacity of 380 mAh g -1 and capacity retention of 82% over 1000 cycles. Moreover, the quasi-solid-state zinc/sodium vanadate hydrate battery is also a good candidate for flexible energy storage device.
Obstacle Detection Algorithms for Rotorcraft Navigation
NASA Technical Reports Server (NTRS)
Kasturi, Rangachar; Camps, Octavia I.; Huang, Ying; Narasimhamurthy, Anand; Pande, Nitin; Ahumada, Albert (Technical Monitor)
2001-01-01
In this research we addressed the problem of obstacle detection for low altitude rotorcraft flight. In particular, the problem of detecting thin wires in the presence of image clutter and noise was studied. Wires present a serious hazard to rotorcrafts. Since they are very thin, their detection early enough so that the pilot has enough time to take evasive action is difficult, as their images can be less than one or two pixels wide. After reviewing the line detection literature, an algorithm for sub-pixel edge detection proposed by Steger was identified as having good potential to solve the considered task. The algorithm was tested using a set of images synthetically generated by combining real outdoor images with computer generated wire images. The performance of the algorithm was evaluated both, at the pixel and the wire levels. It was observed that the algorithm performs well, provided that the wires are not too thin (or distant) and that some post processing is performed to remove false alarms due to clutter.
Fukushima, Toshikazu; Whang, Liang-Ming; Chen, Po-Chun; Putri, Dyah Wulandari; Chang, Ming-Yu; Wu, Yi-Ju; Lee, Ya-Ching
2013-08-01
This study investigated the linkage between performance of two full-scale membrane bioreactor (MBR) systems treating thin-film transistor liquid crystal display (TFT-LCD) wastewater and the population dynamics of dimethylsulfoxide (DMSO)/dimethylsulfide (DMS) degrading bacteria. High DMSO degradation efficiencies were achieved in both MBRs, while the levels of nitrification inhibition due to DMS production from DMSO degradation were different in the two MBRs. The results of real-time PCR targeting on DMSO/DMS degrading populations, including Hyphomicrobium and Thiobacillus spp., indicated that a higher DMSO oxidation efficiency occurred at a higher Hyphomicrobium spp. abundance in the systems, suggesting that Hyphomicrobium spp. may be more important for complete DMSO oxidation to sulfate compared with Thiobacillus spp. Furthermore, Thiobacillus spp. was more abundant during poor nitrification, while Hyphomicrobium spp. was more abundant during good nitrification. It is suggested that microbial population of DMSO/DMS degrading bacteria is closely linking to both DMSO/DMS degradation efficiency and nitrification performance. Copyright © 2013 Elsevier Ltd. All rights reserved.
Independent component analysis for onset detection in piano trills
NASA Astrophysics Data System (ADS)
Brown, Judith C.; Todd, Jeremy G.; Smaragdis, Paris
2002-05-01
The detection of onsets in piano music is difficult due to the presence of many notes simultaneously and their long decay times from pedaling. This is even more difficult for trills where the rapid note changes make it difficult to observe a decrease in amplitude for individual notes in either the temporal wave form or the time dependent Fourier components. Occasionally one note of the trill has a much lower amplitude than the other making an unambiguous determination of its onset virtually impossible. We have analyzed a number of trills from CD's of performances by Horowitz, Ashkenazy, and Goode, choosing the same trill and different performances where possible. The Fourier transform was calculated as a function of time, and the magnitude coefficients served as input for a calculation using the method of independent component analysis. In most cases this gave a more definitive determination of the onset times, as can be demonstrated graphically. For comparison identical calculations have been carried out on recordings of midi generated performances on a Yamaha Disclavier piano.
A visual tracking method based on improved online multiple instance learning
NASA Astrophysics Data System (ADS)
He, Xianhui; Wei, Yuxing
2016-09-01
Visual tracking is an active research topic in the field of computer vision and has been well studied in the last decades. The method based on multiple instance learning (MIL) was recently introduced into the tracking task, which can solve the problem that template drift well. However, MIL method has relatively poor performance in running efficiency and accuracy, due to its strong classifiers updating strategy is complicated, and the speed of the classifiers update is not always same with the change of the targets' appearance. In this paper, we present a novel online effective MIL (EMIL) tracker. A new update strategy for strong classifier was proposed to improve the running efficiency of MIL method. In addition, to improve the t racking accuracy and stability of the MIL method, a new dynamic mechanism for learning rate renewal of the classifier and variable search window were proposed. Experimental results show that our method performs good performance under the complex scenes, with strong stability and high efficiency.
NASA Astrophysics Data System (ADS)
Wang, Minhuan; Feng, Yulin; Bian, Jiming; Liu, Hongzhu; Shi, Yantao
2018-01-01
The mesoscopic perovskite solar cells (M-PSCs) were synthesized with MAPbI3 perovskite layers as light harvesters, which were grown with one-step and two-step solution process, respectively. A comparative study was performed through the quantitative correlation of resulting device performance and the crystalline quality of perovskite layers. Comparing with the one-step counterpart, a pronounced improvement in the steady-state power conversion efficiencies (PCEs) by 56.86% was achieved with two-step process, which was mainly resulted from the significant enhancement in fill factor (FF) from 48% to 77% without sacrificing the open circuit voltage (Voc) and short circuit current (Jsc). The enhanced FF was attributed to the reduced non-radiative recombination channels due to the better crystalline quality and larger grain size with the two-step processed perovskite layer. Moreover, the superiority of two-step over one-step process was demonstrated with rather good reproducibility.
Performance investigations on modified vertical axis water turbine: Combination of lift and drag
NASA Astrophysics Data System (ADS)
Baumatary, Mithinga; Biswas, Angimitra; Misra, Rahul Dev
2018-04-01
Extracting energy from the water has been followed since decades due to environmental friendly. Now a days everyone is running after clean energy, therefore extracting energy from the water turbine is a good approach. The main idea of this study is to investigate the performance of a new design turbine which is a combination of the concepts of lift and drag turbine. The main purpose of the study is to accumulate maximum energy by considering advantages of two different types of turbine. The maximum coefficient of power is 0.141 at free stream velocity of 0.5 m/s. The modified new design turbine consist of straight section and the curve section. The length of the straight section influences the performance of the turbine. Investigation on the optimization of straight section has been carried out in this paper. As this type of turbine have opted the advantages of both lift and drag it has turned out to be fruitful.
28 CFR 523.11 - Meritorious good time.
Code of Federal Regulations, 2010 CFR
2010-07-01
..., AND TRANSFER COMPUTATION OF SENTENCE Extra Good Time § 523.11 Meritorious good time. (a) Staff are responsible for recommending meritorious good time based upon work performance. Each recommendation must... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Meritorious good time. 523.11 Section 523...
28 CFR 523.11 - Meritorious good time.
Code of Federal Regulations, 2012 CFR
2012-07-01
..., AND TRANSFER COMPUTATION OF SENTENCE Extra Good Time § 523.11 Meritorious good time. (a) Staff are responsible for recommending meritorious good time based upon work performance. Each recommendation must... 28 Judicial Administration 2 2012-07-01 2012-07-01 false Meritorious good time. 523.11 Section 523...
28 CFR 523.11 - Meritorious good time.
Code of Federal Regulations, 2013 CFR
2013-07-01
..., AND TRANSFER COMPUTATION OF SENTENCE Extra Good Time § 523.11 Meritorious good time. (a) Staff are responsible for recommending meritorious good time based upon work performance. Each recommendation must... 28 Judicial Administration 2 2013-07-01 2013-07-01 false Meritorious good time. 523.11 Section 523...
28 CFR 523.11 - Meritorious good time.
Code of Federal Regulations, 2014 CFR
2014-07-01
..., AND TRANSFER COMPUTATION OF SENTENCE Extra Good Time § 523.11 Meritorious good time. (a) Staff are responsible for recommending meritorious good time based upon work performance. Each recommendation must... 28 Judicial Administration 2 2014-07-01 2014-07-01 false Meritorious good time. 523.11 Section 523...
28 CFR 523.11 - Meritorious good time.
Code of Federal Regulations, 2011 CFR
2011-07-01
..., AND TRANSFER COMPUTATION OF SENTENCE Extra Good Time § 523.11 Meritorious good time. (a) Staff are responsible for recommending meritorious good time based upon work performance. Each recommendation must... 28 Judicial Administration 2 2011-07-01 2011-07-01 false Meritorious good time. 523.11 Section 523...
NASA Astrophysics Data System (ADS)
Wang, Zhan-zhi; Xiong, Ying
2013-04-01
A growing interest has been devoted to the contra-rotating propellers (CRPs) due to their high propulsive efficiency, torque balance, low fuel consumption, low cavitations, low noise performance and low hull vibration. Compared with the single-screw system, it is more difficult for the open water performance prediction because forward and aft propellers interact with each other and generate a more complicated flow field around the CRPs system. The current work focuses on the open water performance prediction of contra-rotating propellers by RANS and sliding mesh method considering the effect of computational time step size and turbulence model. The validation study has been performed on two sets of contra-rotating propellers developed by David W Taylor Naval Ship R & D center. Compared with the experimental data, it shows that RANS with sliding mesh method and SST k-ω turbulence model has a good precision in the open water performance prediction of contra-rotating propellers, and small time step size can improve the level of accuracy for CRPs with the same blade number of forward and aft propellers, while a relatively large time step size is a better choice for CRPs with different blade numbers.
Reggiori, Giacomo; Mancosu, Pietro; Suchowerska, Natalka; Lobefalo, Francesca; Stravato, Antonella; Tomatis, Stefano; Scorsetti, Marta
2016-02-01
To characterize the performance of a new unshielded silicon diode (Razor-IBA) for dose measurements in small flattening filter free beams. The Razor has an active volume of 0.6 mm in diameter and 20 µm in length. The detector response stability in measured dose, dose rate, dose per pulse, and dark current were evaluated. The detector response in square fields (0.6-5.0 cm) was determined using PDD curves, axial beam profiles and output ratios. The performances were compared to that of the previously available SFD-IBA and PFD-IBA diodes. The Razor short term stability relative to the SFD was much improved (<±0.1% after 1.2 kGy). The linearity was <±1% (0.05-30 Gy range) and the dose rate dependence was <±0.5% (4-24 Gy/min range). The dose per pulse dependence was <±0.7% (0.08-0.21 cGy/pulse range). The PDDs measured with Razor and PFD differed <1%. A larger dark current was observed with increase in dose (0.0025 pA/Gy) compared to the SFD (0.0002 pA/Gy). This characteristic is attributed to an increased concentration of recombination centers. The beam profile showed good agreement with the SFD. Penumbra differences were <±0.3 mm relative to PFD, with a slight overestimation of the tails (<1%), due to the absence of diode shielding. Output ratios were in good agreement for fields up to 5 × 5 cm(2) (<1%). The Razor diode has the same spatial resolution and performance reliability as its predecessor (SFD), but exhibits the additional advantage of improved stability. These features make the Razor diode detector a good candidate for small field dosimetry. Copyright © 2016 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.
Low Income Life-Styles and the Consumption of Durable Goods: Implications for Consumer Educators
ERIC Educational Resources Information Center
Jolly, Desmond A.
1978-01-01
Low-income consumers badly need special purchasing skills, due to merchandising practices and greater markups for durable goods in low-income communities. The author discusses some of the ways in which these people are victimized, with implications for consumer education. (MF)
Discounting of Delayed Rewards Is Not Hyperbolic
ERIC Educational Resources Information Center
Luhmann, Christian C.
2013-01-01
Delay discounting refers to decision-makers' tendency to value immediately available goods more than identical goods available only after some delay. In violation of standard economic theory, decision-makers frequently exhibit dynamic inconsistency; their preferences change simply due to the passage of time. The standard explanation for this…
NASA Astrophysics Data System (ADS)
Tuyls, Pim; Guajardo, Jorge; Batina, Lejla; Kerins, Tim
Counterfeiting of goods is becoming a very huge problem for our society. It not only has a global economic impact, but it also poses a serious threat to our global safety and health. Currently, global economic damage across all industries due to the counterfeiting of goods is estimated at over 600 billion annually [2]. In the United States, seizure of counterfeit goods has tripled in the last 5 years, and in Europe, over 100 million pirated and counterfeit goods were seized in 2004. Fake products cost businesses in the United Kingdom approximately 17 billion [2]. In India, 15% of fast-moving consumer goods and 38% of auto parts are counterfeit. Other industries in which many goods are being counterfeit are the toy industry, content and software, cosmetics, publishing, food and beverages, tobacco, apparel, sports goods, cards, and so forth.
Perceptions of good medical practice in the NHS: a survey of senior health professionals.
Hutchinson, A; Williams, M; Meadows, K; Barbour, R S; Jones, R
1999-12-01
To categorize senior health professionals' experience with poor medical practice in hospitals and in general practice, to describe perceptions which senior NHS staff have of good medical practice, and to describe how problems of poor medical practice are currently managed. A postal questionnaire survey. The questionnaire sought perceptions of good medical practice, asked participants to characterise deviations from good practice, and to describe experience with managing poor performance at the time of the introduction of the General Medical Council (GMC) performance procedures. A range of NHS settings in the UK: hospital trusts, health authorities/boards, local medical committees, community health councils. Senior health professionals involved in the management of medical professional performance. Perceptions of what constitutes good medical practice. Most respondents considered that persistent problems related to clinical practice (diagnosis, management, and outcome and prescribing) would require local management and, possibly, referral to the GMC performance procedures. Informal mechanisms, including informal discussion, education, training, and work shifting, were the most usual means of handling a doctor whose performance was poor. Many took a less serious view of deficiencies in performance on manner and attitude and communication, although consultation skills rather than technical skills comprised the greatest number of complaints about doctors. Senior NHS professionals seem reluctant to consider persistently poor consultation skills in the same critical light as they do persistently poor technical practice. These attitudes may need to change with the implementation of clinical governance and updated guidance from the GMC on what constitutes good medical practice.
NASA Astrophysics Data System (ADS)
Putri, D. O.; Triatmanto, B.; Setiyadi, S.
2018-04-01
Employee performance can be the supporting factor of company performance. However, employee performance can be affected by several factors. Employees can have optimal performance if they feel safe, have good working environment and have discipline. The purposes of this research are to analyze the effect of occupational health and safety, work environment and discipline on the employee performance in PPIC Thermo section in a consumer goods company and to find the dominant variable which primarily affects employee performance. This research was conducted by taking data from 47 respondents. The data were collected using questionnaire. The techniques in data analysis is multiple linear regression with SPSS software. The result shows that occupational health and safety, work environment and discipline are simultaneously significant to the employee performance. Discipline holds the dominant factor which affects employee performance.
Trindade, Mirta; Nording, Malin; Nichkova, Mikaela; Spinnel, Erik; Haglund, Peter; Last, Michael S.; Gee, Shirley; Hammock, Bruce; Last, Jerold A.; González-Sapienza, Gualberto; Brena, Beatriz M.
2010-01-01
Uncontrolled combustion due to garbage recycling is a widespread activity among slum dwellers in distressed economy countries and has been indicated as a major source of dioxin contamination. However, because of the high cost and complexity of gas chromatography/high-resolution mass spectrometry (GC-HRMS) analysis, the magnitude of the problem remains largely unknown. The present study describes a first approach toward the use of a dioxin antibody-based enzyme-linked immunosorbent assay (ELISA) as the basis for a sustainable, simple, and low-cost monitoring program to assess the toxicological impact of uncontrolled combustion in slums. A panel of 16 samples was analyzed by GC-HRMS and ELISA on split extracts. Close to 20% of the analyzed samples showed dioxin concentrations up to almost twice the guidance level for residential soil in several countries, pointing out the need for performing a large-scale monitoring program. Despite the potential for variations in dioxin congener distribution due to the mixed nature of the incinerated material, there was a good correlation between the toxic equivalents as determined by GC-HRMS and ELISA. Furthermore, an interlaboratory ELISA validation showed that the capacity to perform the dioxin ELISA was successfully transferred between laboratories. It was concluded that the ELISA method performed very well as a screening tool to prioritize samples for instrumental analysis, which allows cutting down costs significantly. PMID:18522475
Videothoracoscopy in the treatment of mediastinal cysts
Brzeziński, Daniel; Kozak, Józef
2014-01-01
Introduction Progress in the development of surgical techniques has led to the growing use of video-assisted thoracoscopic surgery (VATS) techniques in mediastinal cyst treatment. Aim To present our experience of treating mediastinal cysts with the minimally invasive technique. Material and methods Fifty patients with mediastinal cysts were treated from 2001 to 2011. There were 32 women and 18 men. The age of the patients ranged from 17 to 72, the mean age being 42 years. All patients underwent basic preoperative diagnostic tests of the chest: X-ray, computed tomography (CT), bronchoscopy and spirometry; 4 patients underwent endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) and 3 fine needle aspiration biopsy (FNAB) of the described lesions. Results The VATS was performed in each case. Conversion was carried out due to superior mediastinal location in 10 cases and pleural adhesions in 3 cases. The partial resection of a cyst was performed in 3 patients. One patient was treated conservatively due to heart failure. In that patient the transthoracic needle aspiration of a cyst under ultrasound guidance using alcoholisation with 76% ethanol with a good effect was performed twice. Cyst recurrence was observed in 1 case. Conclusions The surgical access depends on the location of a cyst. The VATS resection of a superior mediastinal cyst is not always feasible. Surgery of mediastinal cysts is both diagnostic and curative. PMID:25337163
NASA Astrophysics Data System (ADS)
Hu, J.; Zhang, R.; Wang, Y.; Ming, Y.; Lin, Y.; Pan, B.
2015-12-01
Aerosols can alter atmospheric radiation and cloud physics, which further exert impacts on weather and global climate. With the development and industrialization of the developing Asian countries, anthropogenic aerosols have received considerable attentions and remain to be the largest uncertainty in the climate projection. Here we assess the performance of two stat-of-art global climate models (National Center for Atmospheric Research-Community Atmosphere Model 5 (CAM5) and Geophysical Fluid Dynamics Laboratory Atmosphere Model 3 (AM3)) in simulating the impacts of anthropogenic aerosols on North Pacific storm track region. By contrasting two aerosol scenarios, i.e. present day (PD) and pre-industrial (PI), both models show aerosol optical depth (AOD) enhanced by about 22%, with CAM5 AOD 40% lower in magnitude due to the long range transport of anthropogenic aerosols. Aerosol effects on the ice water path (IWP), stratiform precipitation, convergence and convection strengths in the two models are distinctive in patterns and magnitudes. AM3 shows qualitatively good agreement with long-term satellite observations, while CAM5 overestimates convection and liquid water path resulting in an underestimation of large-scale precipitation and IWP. Due to coarse resolution and parameterization in convection schemes, both models' performance on convection needs to be improved. Aerosols performance on large-scale circulation and radiative budget are also examined in this study.
NASA Astrophysics Data System (ADS)
Sabet Bokati, Kazem; Dehghanian, Changiz; Babaei, Mahdi
2018-02-01
The effects of near-surface severe plastic deformation (NS-SPD) on the inhibition performance of sodium molybdate (SM) and 1H-benzotriazole (BTA) for mild steel were investigated using weight loss, polarization and electrochemical impedance spectroscopy measurements. The crystal grain size of NS-SPD-processed surface was analyzed by x-ray diffractometry and field emission scanning electron microscopy. A deformed layer with thickness of 20 ± 5 µm was produced on mild steel surface after NS-SPD process due to accumulated strains. The NS-SPD process caused more effective adsorption of corrosion inhibitors due to the fabrication of a surface with a high density of preferential adsorption sites. However, the stability of protective layer was predominantly influenced by the effect of NS-SPD process on inhibition efficiency. The fairly good persistence of protective layer formed on the surface by SM-containing solution and also positive effect of NS-SPD process on adsorption of molybdate ions caused higher inhibition performance for sodium molybdate. However, NS-SPD process encouraged deterioration of protective layer formed on steel surface in the presence of BTA inhibitor. It was ascribed to partial coverage of surface, low stability of adsorbed layer and thus more adsorption of aggressive ions on unprotected area which was uncovered during immersion time.
Wilson, Sacoby M.; Tarver, Siobhan L.; Svendsen, Erik; Jiang, Chengsheng; Ogunsakin, Olalekan A.; Zhang, Hongmei; Campbell, Dayna; Fraser-Rahim, Herbert
2017-01-01
Abstract As the demand for goods continues to increase, a collective network of transportation systems is required to facilitate goods movement activities. This study examines air quality near the Port of Charleston before its expansion and briefly describes the establishment and structure of a community–university partnership used to monitor existing pollution. Particulate matter (PM) concentrations (PM2.5 and PM10) were measured using the Thermo Fisher Scientific Partisol 2000i-D Dichotomous Air Sampler, Thermo Scientific Dichotomous Sequential Air Sampler Partisol-Plus 2025-D, and Rupprecht & Patashnick TEOM Series 1400 Sampler at neighborhood (Union Heights, Rosemont, and Accabee) and reference (FAA2.5 and Jenkins Street) sites. Descriptive statistics were performed and an ANOVA (analysis of variance) was calculated to find the difference in overall mean 24-hour PM average concentrations in communities impacted by environmental injustice. PM2.5 (15.2 μg/m3) and PM10 (27.2 μg/m3) maximum concentrations were highest in neighborhoods such as Union Heights neighborhoods due to more goods movement activities. Nevertheless, there was no statistically significant difference in mean concentrations of PM2.5 and PM10 across neighborhood sites. In contrast, mean PM10 neighborhood concentrations were significantly lower than mean PM10 reference concentrations for Union Heights (p = 0.00), Accabee (p ≤ 0.0001), and Rosemont (p = 0.01). Although PM concentrations were lower than current National Ambient Air Quality Standards, this study demonstrated how community–university partners can work collectively to document baseline PM concentrations that will be used to examine changes in air quality after the port expansion brings additional goods movement activities to the area. PMID:29576842
Kim, Won Young; Giberson, Tyler A; Uber, Amy; Berg, Katherine; Cocchi, Michael N; Donnino, Michael W
2014-08-01
Previous reports have shown that prolonged duration of resuscitation efforts in out-of-hospital cardiac arrest (OHCA) is associated with poor neurologic outcome. This concept has recently been questioned with advancements in post-cardiac arrest care including the use of therapeutic hypothermia (TH). The aim of this study was to determine the rate of good neurologic outcome based on the duration of resuscitation efforts in OHCA patients treated with TH. This prospective, observational, study was conducted between January 2008 and September 2012. Inclusion criteria consisted of adult non-traumatic OHCA patients who were comatose after return of spontaneous circulation (ROSC) and received TH. The primary endpoint was good neurologic outcome defined as a cerebral performance category score of 1 or 2. Downtime was calculated as the length of time between the patient being recognized as pulseless and ROSC. 105 patients were treated with TH and 19 were excluded due to unknown downtime, leaving 86 patients for analysis. The median downtime was 18.5 (10.0-32.3)min and 33 patients (38.0%) had a good neurologic outcome. When downtime was divided into four groups (≤10min, 11-20min, 21-30min, >30min), good neurologic outcomes were 62.5%, 37%, 25%, and 21.7%, respectively (p=0.02). However, even with downtime >20min, 22.9% had a good neurologic outcome, and this percentage increased to 37.5% in patients with an initial shockable rhythm. Although longer downtime is associated with worse outcome in OHCA patients, we found that comatose patients who have been successfully resuscitated and treated with TH have neurologically intact survival rates of 23% even with downtime >20min. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.
Kim, Won Young; Giberson, Tyler A.; Uber, Amy; Berg, Katherine; Cocchi, Michael N.; Donnino, Michael W.
2014-01-01
Background Previous reports have shown that prolonged duration of resuscitation efforts in out-of-hospital cardiac arrest (OHCA) is associated with poor neurologic outcome. This concept has recently been questioned with advancements in post-cardiac arrest care including the use of therapeutic hypothermia (TH). The aim of this study was to determine the rate of good neurologic outcome based on the duration of resuscitation efforts in OHCA patients treated with TH. Methods This prospective, observational, study was conducted between January 2008 and September 2012. Inclusion criteria consisted of adult non-traumatic OHCA patients who were comatose after return of spontaneous circulation (ROSC) and received TH. The primary endpoint was good neurologic outcome defined as a cerebral performance category score of 1 or 2. Downtime was calculated as the length of time between the patient being recognized as pulseless and ROSC. Results 105 patients were treated with TH and 19 were excluded due to unknown downtime, leaving 86 patients for analysis. The median downtime was 18.5 (10.0–32.3) minutes and 33 patients (38.0%) had a good neurologic outcome. When downtime was divided into four groups (≤10 min, 11-20 min, 21-30 min, > 30 min), good neurologic outcomes were 62.5%, 37%, 25%, and 21.7%, respectively (p=0.02). However, even with downtime >20 minutes, 22.9% had a good neurologic outcome, and this percentage increased to 37.5% in patients with an initial shockable rhythm. Conclusions Although longer downtime is associated with worse outcome in OHCA patients, we found that comatose patients who have been successfully resuscitated and treated with TH have neurologically intact survival rates of 23% even with downtime > 20 minutes. PMID:24746783
Transcontinental anaesthesia: a pilot study.
Hemmerling, T M; Arbeid, E; Wehbe, M; Cyr, S; Giunta, F; Zaouter, C
2013-05-01
Although telemedicine is one of the key initiatives of the World Health Organization, no study has explored the feasibility and efficacy of teleanaesthesia. This bi-centre pilot study investigates the feasibility of transcontinental anaesthesia. Twenty patients aged ≥ 18 yr undergoing elective thyroid surgery for ≥ 30 min were enrolled in this study. The remote and local set-up was composed of a master-computer (Montreal) and a slave-computer (Pisa). Standard Internet connection, remote desktop control, and video conference software were used. All patients received total i.v. anaesthesia controlled remotely (Montreal). The main outcomes were feasibility, clinical performance, and controller performance of transcontinental anaesthesia. The clinical performance of hypnosis control was the efficacy to maintain bispectral index (BIS) at 45: 'excellent', 'good', 'poor', and 'inadequate' control represented BIS values within 10, from 11 to 20, from 21 to 30, or >30% from target. The clinical performance of analgesia was the efficacy to maintain Analgoscore values at 0 (-9 to 9); -3 to +3 representing 'excellent' pain control, -3 to -6 and +3 to +6 representing 'good' pain control, and -6 to -9 and +6 to +9 representing 'insufficient' pain control. The controller performance was evaluated using Varvel parameters. Transcontinental anaesthesia was successful in all 20 consecutive patients. The clinical performance of hypnosis showed an 'excellent and good' control for 69% of maintenance time, and the controller performance showed an average global performance index of 57. The clinical performance of analgesia was 'excellent and good' for 92% of maintenance time, and the controller performance showed a global performance index of 1118. Transcontinental anaesthesia is feasible; control of anaesthesia shows good performance indexes. Clinical registration number NCT01331096.
Distinct Aging Effects on Functional Networks in Good and Poor Cognitive Performers
Lee, Annie; Tan, Mingzhen; Qiu, Anqi
2016-01-01
Brain network hubs are susceptible to normal aging processes and disruptions of their functional connectivity are detrimental to decline in cognitive functions in older adults. However, it remains unclear how the functional connectivity of network hubs cope with cognitive heterogeneity in an aging population. This study utilized cognitive and resting-state functional magnetic resonance imaging data, cluster analysis, and graph network analysis to examine age-related alterations in the network hubs’ functional connectivity of good and poor cognitive performers. Our results revealed that poor cognitive performers showed age-dependent disruptions in the functional connectivity of the right insula and posterior cingulate cortex (PCC), while good cognitive performers showed age-related disruptions in the functional connectivity of the left insula and PCC. Additionally, the left PCC had age-related declines in the functional connectivity with the left medial prefrontal cortex (mPFC) and anterior cingulate cortex (ACC). Most interestingly, good cognitive performers showed age-related declines in the functional connectivity of the left insula and PCC with their right homotopic structures. These results may provide insights of neuronal correlates for understanding individual differences in aging. In particular, our study suggests prominent protection roles of the left insula and PCC and bilateral ACC in good performers. PMID:27667972
2017-01-01
Graphitic carbon anodes have long been used in Li ion batteries due to their combination of attractive properties, such as low cost, high gravimetric energy density, and good rate capability. However, one significant challenge is controlling, and optimizing, the nature and formation of the solid electrolyte interphase (SEI). Here it is demonstrated that carbon coating via chemical vapor deposition (CVD) facilitates high electrochemical performance of carbon anodes. We examine and characterize the substrate/vertical graphene interface (multilayer graphene nanowalls coated onto carbon paper via plasma enhanced CVD), revealing that these low-tortuosity and high-selection graphene nanowalls act as fast Li ion transport channels. Moreover, we determine that the hitherto neglected parallel layer acts as a protective surface at the interface, enhancing the anode performance. In summary, these findings not only clarify the synergistic role of the parallel functional interface when combined with vertical graphene nanowalls but also have facilitated the development of design principles for future high rate, high performance batteries. PMID:29392179
NASA Technical Reports Server (NTRS)
Gamwell, W. R.; McGill, P. B.
2006-01-01
Aluminum-Beryllium metal matrix composite materials are useful due to their desirable performance characteristics for aerospace applications. Desirable characteristics of this material includes light-weight, dimensional stability, stiffness, good vibration damping characteristics, low coefficient of thermal expansion, and workability, This material is 3.5 times stiffer and 22% lighter than conventional aluminum alloys. electro-optical systems, advanced sensor and guidance components for flight and satellite systems, components for light-weight high-performance aircraft engines, and structural components for helicopters. Aluminum-beryllium materials are now available in the form of near net shape investment castings. In this materials properties characterization study, the cryogenic tensile and fracture properties of an investment casting alloy, Beralcast 363, were determined. Tensile testing was performed at 21 C (70 F), -73.3 C (-100 F), -195.5 C (-320 F) and -252.8 C (-423 F), and fracture (K(sub lc) and da/dN) testing was performed at -73.3 C (-100 F), -195.5 C (-320 F) and -252.8 C (-423 F). Their use is attractive for weight critical structural applications such as advanced
NASA Technical Reports Server (NTRS)
Revankar, Vithal; Hlavacek, Vladimir
1991-01-01
The chemical vapor deposition (CVD) synthesis of fibers capable of effectively reinforcing intermetallic matrices at elevated temperatures which can be used for potential applications in high temperature composite materials is described. This process was used due to its advantage over other fiber synthesis processes. It is extremely important to produce these fibers with good reproducible and controlled growth rates. However, the complex interplay of mass and energy transfer, blended with the fluid dynamics makes this a formidable task. The design and development of CVD reactor assembly and system to synthesize TiB2, CrB, B4C, and TiC fibers was performed. Residual thermal analysis for estimating stresses arising form thermal expansion mismatch were determined. Various techniques to improve the mechanical properties were also performed. Various techniques for improving the fiber properties were elaborated. The crystal structure and its orientation for TiB2 fiber is discussed. An overall view of the CVD process to develop CrB2, TiB2, and other high performance ceramic fibers is presented.
Encoding of speech sounds at auditory brainstem level in good and poor hearing aid performers.
Shetty, Hemanth Narayan; Puttabasappa, Manjula
Hearing aids are prescribed to alleviate loss of audibility. It has been reported that about 31% of hearing aid users reject their own hearing aid because of annoyance towards background noise. The reason for dissatisfaction can be located anywhere from the hearing aid microphone till the integrity of neurons along the auditory pathway. To measure spectra from the output of hearing aid at the ear canal level and frequency following response recorded at the auditory brainstem from individuals with hearing impairment. A total of sixty participants having moderate sensorineural hearing impairment with age range from 15 to 65 years were involved. Each participant was classified as either Good or Poor Hearing aid Performers based on acceptable noise level measure. Stimuli /da/ and /si/ were presented through loudspeaker at 65dB SPL. At the ear canal, the spectra were measured in the unaided and aided conditions. At auditory brainstem, frequency following response were recorded to the same stimuli from the participants. Spectrum measured in each condition at ear canal was same in good hearing aid performers and poor hearing aid performers. At brainstem level, better F 0 encoding; F 0 and F 1 energies were significantly higher in good hearing aid performers than in poor hearing aid performers. Though the hearing aid spectra were almost same between good hearing aid performers and poor hearing aid performers, subtle physiological variations exist at the auditory brainstem. The result of the present study suggests that neural encoding of speech sound at the brainstem level might be mediated distinctly in good hearing aid performers from that of poor hearing aid performers. Thus, it can be inferred that subtle physiological changes are evident at the auditory brainstem in a person who is willing to accept noise from those who are not willing to accept noise. Copyright © 2016 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Published by Elsevier Editora Ltda. All rights reserved.
EnviroAtlas: A Tool for Accessing, Viewing, & Analyzing Diverse Information for Better Decisions
EnviroAtlas provides interactive tools and resources for exploring the benefits people receive from nature or :ecosystem goods and services.: Ecosystem goods and services are critically important to human health and well-being, but they are often overlooked due to lack of informa...
75 FR 23637 - Injury and Illness Prevention Program
Federal Register 2010, 2011, 2012, 2013, 2014
2010-05-04
..., hand (courier) delivery, and messenger service. Send your request to: Eastern Research Group, Inc., 110... Commission (OSHRC) the authority to assess civil penalties giving due consideration to the good faith of the... employers who have violated OSHA standards but who have demonstrated a good faith effort to provide a safe...
Raaschou-Jensen, Klas; Katzenstein, Terese L.; Marquart, Hanne; Ryder, Lars; Daugaard, Gedske
2010-01-01
A case of persistent B-cell lymphocytopenia in a 40-year-old woman with lymphoid-epithelial thymoma treated with chemotherapy, surgery and irradiation is described. The possible diagnosis of Good's syndrome (hypogammaglobulinaemia and thymoma) is discussed. PMID:20740204
NASA Astrophysics Data System (ADS)
Kong, Changduk; Lim, Semyeong
2011-12-01
Recently, the health monitoring system of major gas path components of gas turbine uses mostly the model based method like the Gas Path Analysis (GPA). This method is to find quantity changes of component performance characteristic parameters such as isentropic efficiency and mass flow parameter by comparing between measured engine performance parameters such as temperatures, pressures, rotational speeds, fuel consumption, etc. and clean engine performance parameters without any engine faults which are calculated by the base engine performance model. Currently, the expert engine diagnostic systems using the artificial intelligent methods such as Neural Networks (NNs), Fuzzy Logic and Genetic Algorithms (GAs) have been studied to improve the model based method. Among them the NNs are mostly used to the engine fault diagnostic system due to its good learning performance, but it has a drawback due to low accuracy and long learning time to build learning data base if there are large amount of learning data. In addition, it has a very complex structure for finding effectively single type faults or multiple type faults of gas path components. This work builds inversely a base performance model of a turboprop engine to be used for a high altitude operation UAV using measured performance data, and proposes a fault diagnostic system using the base engine performance model and the artificial intelligent methods such as Fuzzy logic and Neural Network. The proposed diagnostic system isolates firstly the faulted components using Fuzzy Logic, then quantifies faults of the identified components using the NN leaned by fault learning data base, which are obtained from the developed base performance model. In leaning the NN, the Feed Forward Back Propagation (FFBP) method is used. Finally, it is verified through several test examples that the component faults implanted arbitrarily in the engine are well isolated and quantified by the proposed diagnostic system.
Fabric strain sensor integrated with CNPECs for repeated large deformation
NASA Astrophysics Data System (ADS)
Yi, Weijing
Flexible and soft strain sensors that can be used in smart textiles for wearable applications are much desired. They should meet the requirements of low modulus, large working range and good fatigue resistance as well as good sensing performances. However, there were no commercial products available and the objective of the thesis is to investigate fabric strain sensors based on carbon nanoparticle (CNP) filled elastomer composites (CNPECs) for potential wearing applications. Conductive CNPECs were fabricated and investigated. The introduction of silicone oil (SO) significantly decreased modulus of the composites to less than 1 MPa without affecting their deformability and they showed good stability after heat treatment. With increase of CNP concentration, a percolation appeared in electrical resistivity and the composites can be divided into three ranges. I-V curves and impedance spectra together with electro-mechanical studies demonstrated a balance between sensitivity and working range for the composites with CNP concentrations in post percolation range, and were preferred for sensing applications only if the fatigue life was improved. Due to the good elasticity and failure resist property of knitted fabric under repeated extension, it was adopted as substrate to increase the fatigue life of the conductive composites. After optimization of processing parameters, the conductive fabric with CNP concentration of 9.0CNP showed linear I-V curves when voltage is in the range of -1 V/mm and 1 V/mm and negligible capacitive behavior when frequency below 103 Hz even with strain of 60%. It showed higher sensitivity due to the combination of nonlinear resistance-strain behavior of the CNPECs and non-even strain distribution of knitted fabric under extension. The fatigue life of the conductive fabric was greatly improved. Extended on the studies of CNPECs and the coated conductive fabrics, a fabric strain sensor was designed, fabricated and packaged. The Young's modulus of the packaged fabric strain sensor was less than 1 MPa; the strain gauge factor was 4.76 within the strain range of 0-40% and the hysteresis was 5.5%; the resistance relaxation was 5.56% with a constant strain of 40%; the fatigue life of the sensor was more than 100,000 cycles.
Evaluation of Lumipulse® G1200 for the measurement of six tumor markers: Comparison with AIA® 2000.
de Rancher, Marie-Aude Robert; Oudart, Jean-Baptiste; Maquart, François-Xavier; Monboisse, Jean Claude; Ramont, Laurent
2016-11-01
Tumor marker assays are daily practiced, for screening and follow up of cancers. Interassay precision is an important parameter for the interpretation of the kinetics of the markers, in order to conclude to the efficiency or failure of treatment. The aim of this study was to compare two automated Immunoassay analyzers, Lumipulse® G1200 and AIA® 2000. Both analyzers used an immunoassay system but with different antibodies. Six tumor markers commonly used were studied: AFP, PSA, CA 19-9, CA 15-3, CA 125 and CEA. 253 samples have been collected over a period of one month and analyzed by both analyzers. Regression of Passing-Badblock and Bland-Altman diagram were used to analyze the results for AFP (n=36), PSA (n=39), CA-125 (n=40), CA 15-3 (n=40), CA 19-9 (n=46) and CEA (n=52) were performed. Analytical performances of Lumipulse® G1200 highlighted the good inter-run and intra-run precision of the analyzer. We obtained a good correlation coefficient between Lumipulse G1200® and AIA 2000®, >0.96 for most markers except CA 19-9 which provided a correlation coefficient significantly lower than that obtained with other markers. The concordance for all markers was >94% except for CA 19-9 (83.7%). This study showed a good correlation between the two analyzers and, therefore, a transfer from one analyzer to the other is possible for the different markers studied. However, we found here the classical difficulty to transfer this type of analysis, due to the absence of method standardization. This difficulty was particularly illustrated by CA19-9. Copyright © 2016 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.
Lacorte, Silvia; Guillamon, Míriam
2008-08-01
This study reports an efficient method for the determination of 40 PBDEs from mono- to hepta-brominated in human milk. Pressurized liquid extraction (PLE) was optimized to recover PBDEs in a quantitative way using 1g of freeze dried milk. Due to the great amount of coextracted compounds, the clean-up step was optimized using alumina SPE disposable cartridges of 2 and 5 g. Whereas 2g alumina SPE failed in providing good extraction yields, all PBDEs were satisfactorily recovered using 5 g alumina SPE cartridges. Detection was performed with gas chromatography coupled to mass spectrometry with negative chemical ionization and method detection limits ranged from 0.01 to 0.05 microg kg(-1) wet weight (ww) with a good intra and inter-day variation (coefficient of variation lower than 13.4%). This method was validated by participating in an interlaboratory exercise from Quasimeme (United Kingdom), where a standard solution containing seven congeners and a certified unspiked mothers' milk were analyzed. In the standard mixture, levels between 96.915 and 570.172 microg l(-1) were quantified, whereas in certified mothers' milk, BDEs 47, 99, 100 and 154 were detected at levels from 0.010 and 0.061 microg kg(-1) ww, with an error <30%. The applicability of the method was tested experimentally in five mothers' milk samples, where only BDE 47 was detected at a maximum concentration of 10.45 microg kg(-1) lipid weight (lw). PLE succeeded in extracting all PBDEs from the sample with good reproducibility although the clean-up step had to be severely performed to eliminate sample interferences such as milk lipids and proteins.
Analysis of pharmaceutical adulterants in plant food supplements by UHPLC-MS/MS.
Paíga, Paula; Rodrigues, Manuela J E; Correia, Manuela; Amaral, Joana S; Oliveira, M Beatriz P P; Delerue-Matos, Cristina
2017-03-01
A method based on the Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) extraction and ultra-high performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS) was successfully developed and validated for the analysis of 26 pharmaceutical compounds belonging to different therapeutic classes (anorexics, stimulants, anxiolytics, antidepressants and laxatives), which are all prone to be illegally added into weight-loss plant food supplements (PFS) for their pharmacological activity. Internal standard calibration with six isotopically labelled compounds rendered good linearity in the range of 5 to 1000μg/l, depending on the compound, and good sensitivity with limits of quantification in the range of 0.02-9.80μg/l. Recoveries were assessed for all the 16 samples analysed and were found between 70% and 120% for over 90% of the analytes. The average recovery value was 90.8%, for the different studied matrices (liquids, liquid ampoules, tablets and capsules), with RSD values lower than 10% for all forms. The changes introduced to the QuEChERS procedure maintained the good performance characteristics of the extraction method while preserving the chromatographic system for the introduction of unwanted matrix compounds. Synephrine was the only compound detected and quantified in one sample, but at a very low concentration (768μg/l) and its presence may be due to the plant extracts used in the formulation, as synephrine is known to be a natural constituent of Citrus aurantium amara. Despite none of the 16 evaluated samples were found to be adulterated by the illegal addition of the drugs included in this work, the developed methodology can be very useful for monitoring the adulteration of weight-loss PFS. Copyright © 2016 Elsevier B.V. All rights reserved.
Neurophysiological prediction of neurological good and poor outcome in post-anoxic coma.
Grippo, A; Carrai, R; Scarpino, M; Spalletti, M; Lanzo, G; Cossu, C; Peris, A; Valente, S; Amantini, A
2017-06-01
Investigation of the utility of association between electroencephalogram (EEG) and somatosensory-evoked potentials (SEPs) for the prediction of neurological outcome in comatose patients resuscitated after cardiac arrest (CA) treated with therapeutic hypothermia, according to different recording times after CA. Glasgow Coma Scale, EEG and SEPs performed at 12, 24 and 48-72 h after CA were assessed in 200 patients. Outcome was evaluated by Cerebral Performance Category 6 months after CA. Within 12 h after CA, grade 1 EEG predicted good outcome and bilaterally absent (BA) SEPs predicted poor outcome. Because grade 1 EEG and BA-SEPs were never found in the same patient, the recording of both EEG and SEPs allows us to correctly prognosticate a greater number of patients with respect to the use of a single test within 12 h after CA. At 48-72 h after CA, both grade 2 EEG and BA-SEPs predicted poor outcome with FPR=0.0%. When these neurophysiological patterns are both present in the same patient, they confirm and strengthen their prognostic value, but because they also occurred independently in eight patients, poor outcome is predictable in a greater number of patients. The combination of EEG/SEP findings allows prediction of good and poor outcome (within 12 h after CA) and of poor outcome (after 48-72 h). Recording of EEG and SEPs in the same patients allows always an increase in the number of cases correctly classified, and an increase of the reliability of prognostication in a single patient due to concordance of patterns. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.
Investigation of Re-X glass ceramic for acceleration insulating columns
NASA Astrophysics Data System (ADS)
Faltens, A.; Rosenblum, S.
1985-05-01
In an induction linac the accelerating voltage appears along a voltage-graded vacuum insulator column which is a performance limiting and major cost component. Re-X glass ceramic insulators have the long-sought properties of allowing cast-in gradient electrodes, good breakdown characteristics, and compatibility with high vacuum systems. Re-X is a glass ceramic developed by General Electric for use in the manufacture of electrical apparatus, such as vacuum arc interrupters. We have examined vacuum outgassing behavior and voltage breakdown in vacuum and find excellent performance. The housings are in the shape of tubes with type 430 stainless steel terminations. Due to a matched coefficient of thermal expansion between metal and insulator, no vacuum leaks have resulted from any welding operation. The components should be relatively inexpensive to manufacture in large sizes and appear to be a very attractive accelerator column. We are planning to use a standard GE housing in our MBE-4 induction linac.
Kis, Anna; Szakadát, Sára; Gácsi, Márta; Kovács, Enikő; Simor, Péter; Török, Csenge; Gombos, Ferenc; Bódizs, Róbert; Topál, József
2017-01-01
The active role of sleep in memory consolidation is still debated, and due to a large between-species variation, the investigation of a wide range of different animal species (besides humans and laboratory rodents) is necessary. The present study applied a fully non-invasive methodology to study sleep and memory in domestic dogs, a species proven to be a good model of human awake behaviours. Polysomnography recordings performed following a command learning task provide evidence that learning has an effect on dogs’ sleep EEG spectrum. Furthermore, spectral features of the EEG were related to post-sleep performance improvement. Testing an additional group of dogs in the command learning task revealed that sleep or awake activity during the retention interval has both short- and long-term effects. This is the first evidence to show that dogs’ human-analogue social learning skills might be related to sleep-dependent memory consolidation. PMID:28165489
Practical aspects of protein co-evolution.
Ochoa, David; Pazos, Florencio
2014-01-01
Co-evolution is a fundamental aspect of Evolutionary Theory. At the molecular level, co-evolutionary linkages between protein families have been used as indicators of protein interactions and functional relationships from long ago. Due to the complexity of the problem and the amount of genomic data required for these approaches to achieve good performances, it took a relatively long time from the appearance of the first ideas and concepts to the quotidian application of these approaches and their incorporation to the standard toolboxes of bioinformaticians and molecular biologists. Today, these methodologies are mature (both in terms of performance and usability/implementation), and the genomic information that feeds them large enough to allow their general application. This review tries to summarize the current landscape of co-evolution-based methodologies, with a strong emphasis on describing interesting cases where their application to important biological systems, alone or in combination with other computational and experimental approaches, allowed getting new insight into these.
Practical aspects of protein co-evolution
Ochoa, David; Pazos, Florencio
2014-01-01
Co-evolution is a fundamental aspect of Evolutionary Theory. At the molecular level, co-evolutionary linkages between protein families have been used as indicators of protein interactions and functional relationships from long ago. Due to the complexity of the problem and the amount of genomic data required for these approaches to achieve good performances, it took a relatively long time from the appearance of the first ideas and concepts to the quotidian application of these approaches and their incorporation to the standard toolboxes of bioinformaticians and molecular biologists. Today, these methodologies are mature (both in terms of performance and usability/implementation), and the genomic information that feeds them large enough to allow their general application. This review tries to summarize the current landscape of co-evolution-based methodologies, with a strong emphasis on describing interesting cases where their application to important biological systems, alone or in combination with other computational and experimental approaches, allowed getting new insight into these. PMID:25364721
A potential drop strain sensor for in-situ power station creep monitoring
NASA Astrophysics Data System (ADS)
Corcoran, Joseph; Cawley, Peter; Nagy, Peter B.
2014-02-01
Creep is a high temperature damage mechanism of interest to the power industry and at present lacks a satisfactory inspection technique. Existing material inspection techniques are extremely laborious while strain measurements rely on often infrequent off-load measurements. A quasi-DC directional potential drop technique has been suggested that is able to suppress the effects of permeability and is primarily sensitive to changes in resistivity and also the geometry that will develop through strain. The change in creep related resistivity is shown by an equivalent effective resistivity approach to be small at <2% change when compared to the >100% change in transfer resistance that occurs due to strain as observed in laboratory tests. A biaxial inversion is then presented and demonstrated on in-lab samples showing good performance. The result is a sensor that performs as a very robust high temperature strain gauge.
Optimizing piezoelectric receivers for acoustic power transfer applications
NASA Astrophysics Data System (ADS)
Gorostiaga, M.; Wapler, M. C.; Wallrabe, U.
2018-07-01
In this paper, we aim to optimize piezoelectric plate receivers for acoustic power transfer applications by analyzing the influence of the losses and of the acoustic boundary conditions. We derive the analytic expressions of the efficiency of the receiver with the optimal electric loads attached, and analyze the maximum efficiency value and its frequency with different loss and acoustic boundary conditions. To validate the analytical expressions that we have derived, we perform experiments in water with composite transducers of different filling fractions, and see that a lower acoustic impedance mismatch can compensate the influence of large dielectric and acoustic losses to achieve a good performance. Finally, we briefly compare the advantages and drawbacks of composite transducers and pure PZT (lead zirconate titanate) plates as acoustic power receivers, and conclude that 1–3 composites can achieve similar efficiency values in low power applications due to their adjustable acoustic impedance.
Preparation and application of silver nanopaste as thermal interface materials
NASA Astrophysics Data System (ADS)
Zou, Lianfeng
The power densities in electronic devices have increased dramatically; heat dissipation has become a major challenge in high performance electronics applications. We have investigated a new type of resin-free hybrid silver nanopastes, which contain silver micro-flakes with particle sizes of 1 - 10 um and silver nanoparticles with diameters of 3 - 8 nm. The assemble temperature can be as low as 150oC due to the low sintering temperature of silver nanoparticles. The fused silver micro-and nanoparticles in TIM form continuous metallic networks, resulting in good thermal, electrical and mechanical bonding. The steady-state thermal gradient measurement show the bulk thermal conductivity between 20W/ (m*K) and 100 W/ (m*K), which is higher than commercial product in the market. The application specific performance of the nanopaste has been using LED lamp on heat sinks as model test vehicle.
Bioinspired locomotion and grasping in water: the soft eight-arm OCTOPUS robot.
Cianchetti, M; Calisti, M; Margheri, L; Kuba, M; Laschi, C
2015-05-13
The octopus is an interesting model for the development of soft robotics, due to its high deformability, dexterity and rich behavioural repertoire. To investigate the principles of octopus dexterity, we designed an eight-arm soft robot and evaluated its performance with focused experiments. The OCTOPUS robot presented here is a completely soft robot, which integrates eight arms extending in radial direction and a central body which contains the main processing units. The front arms are mainly used for elongation and grasping, while the others are mainly used for locomotion. The robotic octopus works in water and its buoyancy is close to neutral. The experimental results show that the octopus-inspired robot can walk in water using the same strategy as the animal model, with good performance over different surfaces, including walking through physical constraints. It can grasp objects of different sizes and shapes, thanks to its soft arm materials and conical shape.
Safety of Lumbar Puncture Procedures in Patients with Alzheimer's Disease
Peskind, E.; Nordberg, A.; Darreh-Shori, T.; Soininen, H.
2014-01-01
Changes in cerebrospinal fluid (CSF) biomarkers are representative of biochemical changes in the brain. Collection of CSF by lumbar puncture (LP) is essential for biomarker analysis, which is important for research in neurodegenerative disorders. However, LP for research purposes has been controversial due to a reported high incidence of severe LP headache when using standard 18g or 20g Quincke needles with a beveled cutting tip. A procedural safety analysis was performed using the database of a multicenter, 13-week study of CSF cholinesterase activity. A 24g Sprotte atraumatic needle was used to collect CSF at baseline and at Week 13 from 63 older patients with mild to moderate Alzheimer's disease. There was a < 2% LP headache incidence, and a favorable safety profile was reported. In conclusion, LP performed with a 24g Sprotte atraumatic needle (blunt, “bullet” tip) was a well-tolerated procedure, with good acceptability. PMID:19519311
Leccese, Fabio; Cagnetti, Marco; Trinca, Daniele
2014-01-01
A smart city application has been realized and tested. It is a fully remote controlled isle of lamp posts based on new technologies. It has been designed and organized in different hierarchical layers, which perform local activities to physically control the lamp posts and transmit information with another for remote control. Locally, each lamp post uses an electronic card for management and a ZigBee tlc network transmits data to a central control unit, which manages the whole isle. The central unit is realized with a Raspberry-Pi control card due to its good computing performance at very low price. Finally, a WiMAX connection was tested and used to remotely control the smart grid, thus overcoming the distance limitations of commercial Wi-Fi networks. The isle has been realized and tested for some months in the field. PMID:25529206
Double-shell CuS nanocages as advanced supercapacitor electrode materials
NASA Astrophysics Data System (ADS)
Guo, Jinxue; Zhang, Xinqun; Sun, Yanfang; Zhang, Xiaohong; Tang, Lin; Zhang, Xiao
2017-07-01
Metal sulfides hollow structures are advanced materials for energy storage applications of lithium-ion batteries and supercapacitors. However, constructing hollow metal sulfides with specific features, such as multi-shell and non-spherical shape, still remains great challenge. In this work, we firstly demonstrate the synthesis of CuS double-shell hollow nanocages using Cu2O nanocubes as precursors. The synthesis processes involve the repeated anion exchange reaction with Na2S and the controllable etching using hydrochloric acid. The whole synthesis processes are well revealed and the obtained double-shell CuS is tested as pseudocapacitive electrode material for supercapacitors. As expected, the CuS double-shell hollow nanocages deliver high specific capacitance, good rate performance and excellent cycling stability due to their unique nano-architecture. The present work contributes greatly to the exploration of hollow metal sulfides with complex architecture and non-spherical shape, as well as their promising application in high-performance electrochemical supercapacitors.
Innovative scheme for high-repetition-rate imaging of CN radical.
Satija, Aman; Ruesch, Morgan D; Powell, Michael S; Son, Steven F; Lucht, Robert P
2018-02-01
We have employed, to the best of our knowledge, a novel excitation scheme to perform the first high-repetition-rate planar laser-induced fluorescence (PLIF) measurements of a CN radical in combustion. The third harmonic of a Nd:YVO 4 laser at 355 nm due to its relatively large linewidth overlaps with several R branch transitions in a CN ground electronic state. Therefore, the 355 nm beam was employed to directly excite the CN transitions with good efficiency. The CN measurements were performed in premixed CH 4 -N 2 O flames with varying equivalence ratios. A detailed characterization of the high-speed CN PLIF imaging system is presented via its ability to capture statistical and dynamical information in these premixed flames. Single-shot CN PLIF images obtained over a HMX pellet undergoing self-supported deflagration are presented as an example of the imaging system being applied towards characterizing the flame structure of energetic materials.
[Follow-up on MEWDS by fundus perimetry and multifocal ERG with the SLO].
Bültmann, S; Martin, M; Rohrschneider, K
2002-09-01
Most conventional techniques for examination such as perimetry or ERG may not be sensitive enough to detect functional alterations due to MEWDS precisely. We report on a follow-up performed by fundus perimetry and the new technique of multifocal ERG using the scanning laser ophthalmoscope. A 24-year-old female patient (VA 0.2/0.8) was followed up for 7 weeks with these techniques as well as Octopus perimetry, fluorescence angiography, Ganzfeld ERG and biomicroscopy. Multifocal ERG stimulation (mfERG, Retiscan) was performed with the SLO. Visual acuity improved from 0.2 to 0.8 and the central relative scotoma disappeared while a relevant increase of P1-wave amplitudes in mfERG could be observed. Combining objective measurements from the fundus controlled SLO-mfERG and results from fundus perimetry enable good correlation of morphology and results, even for minor alterations of the macula only accessible by few established clinical examinations.
Flexible thin-film battery based on solid-like ionic liquid-polymer electrolyte
NASA Astrophysics Data System (ADS)
Li, Qin; Ardebili, Haleh
2016-01-01
The development of high-performance flexible batteries is imperative for several contemporary applications including flexible electronics, wearable sensors and implantable medical devices. However, traditional organic liquid-based electrolytes are not ideal for flexible batteries due to their inherent safety and stability issues. In this study, a non-volatile, non-flammable and safe ionic liquid (IL)-based polymer electrolyte film with solid-like feature is fabricated and incorporated in a flexible lithium ion battery. The ionic liquid is 1-Ethyl-3-methylimidazolium dicyanamide (EMIMDCA) and the polymer is composed of poly(vinylidene fluoride-co-hexafluoropropene) (PVDF-HFP). The electrolyte exhibits good thermal stability (i.e. no weight loss up to 300 °C) and relatively high ionic conductivity (6 × 10-4 S cm-1). The flexible thin-film lithium ion battery based on solid-like electrolyte film is encapsulated using a thermal-lamination process and demonstrates excellent electrochemical performance, in both flat and bent configurations.
Phaeochromocytoma presenting as an acute coronary syndrome.
Imam, Towhid; Finny, Philip; Choo-Kang, Alan; Khan, Rehman
2016-10-26
A 44-year-old Caucasian man presented to the emergency department in acute cardiogenic shock, with pulmonary oedema, secondary to an acute myocardial infarction and in a hyperosmolar hyperglycaemic state. The previous day he had undergone a colonoscopy, which revealed features of colitis, and was started on prednisolone. He had been previously diagnosed with type 2 diabetes, migraine and anxiety attacks. While awaiting a coronary angiogram he developed abdominal pain and a CT scan was performed and found a large right adrenal mass. Plasma-free metadrenaline levels were elevated. After 4 months, a right adrenalectomy was performed successfully. He made a good recovery with normalisation of his heart function and resolution of his diabetes. The diagnosis was delayed for years due to his episodic symptoms being attributed to other more common diagnoses. Although a rare diagnosis in itself, there are case reports of phaeochromocytoma initially presenting with an acute coronary syndrome. 2016 BMJ Publishing Group Ltd.
Decoupled Ion Transport in a Protein-Based Solid Ion Conductor.
Fu, Xuewei; Jewel, Yead; Wang, Yu; Liu, Jin; Zhong, Wei-Hong
2016-11-03
Simultaneous achievement of good electrochemical and mechanical properties is crucial for practical applications of solid ion conductors. Conventional polymer conductors suffer from low conductivity, low transference number, and deteriorated mechanical properties with the enhancement of conductivity, resulting from the coupling between ion transport and polymer movement. Here we present a successful fabrication and fundamental understanding of a high performance soy protein-based solid conductor. The conductor shows ionic conductivity of ∼10 -5 S/cm, transference number of 0.94, and modulus of 1 GPa at room temperature, and still remains flexible and easily processable. Molecular simulations indicate that this is due to appropriate manipulation of the protein structures for effective exploitation of protein functional groups. A decoupled transport mechanism, which is able to explain all results, is proposed. The new insights can be utilized to provide guidelines for design, optimization, and fabrication of high performance biosolid conductors.
Leccese, Fabio; Cagnetti, Marco; Trinca, Daniele
2014-12-18
A smart city application has been realized and tested. It is a fully remote controlled isle of lamp posts based on new technologies. It has been designed and organized in different hierarchical layers, which perform local activities to physically control the lamp posts and transmit information with another for remote control. Locally, each lamp post uses an electronic card for management and a ZigBee tlc network transmits data to a central control unit, which manages the whole isle. The central unit is realized with a Raspberry-Pi control card due to its good computing performance at very low price. Finally, a WiMAX connection was tested and used to remotely control the smart grid, thus overcoming the distance limitations of commercial Wi-Fi networks. The isle has been realized and tested for some months in the field.
NASA Astrophysics Data System (ADS)
Steiner, Adam M.; Yager-Elorriaga, David A.; Patel, Sonal G.; Jordan, Nicholas M.; Gilgenbach, Ronald M.; Safronova, Alla S.; Kantsyrev, Victor L.; Shlyaptseva, Veronica V.; Shrestha, Ishor; Schmidt-Petersen, Maximillian T.
2016-10-01
Implosions of planar wire arrays were performed on the Michigan Accelerator for Inductive Z-pinch Experiments, a linear transformer driver (LTD) at the University of Michigan. These experiments were characterized by lower than expected peak currents and significantly longer risetimes compared to studies performed on higher impedance machines. A circuit analysis showed that the load inductance has a significant impact on the current output due to the comparatively low impedance of the driver; the long risetimes were also attributed to high variability in LTD switch closing times. A circuit model accounting for these effects was employed to measure changes in load inductance as a function of time to determine plasma pinch timing and calculate a minimum effective current-carrying radius. These calculations showed good agreement with available shadowgraphy and x-ray diode measurements.
Novel magnetic-fluorescent bifunctional Janus nanofiber membrane
NASA Astrophysics Data System (ADS)
Wang, Qiutong; Geng, Yuting; Li, Jianhao; Yin, Meizhen; Hu, Yiseng; Liu, Yangxiu; Pan, Kai
2018-04-01
Magnetic-fluorescent bifunctional materials have received global attention owing to their potential in many fields. Herein, we reported a novel magnetic-fluorescent bifunctional Janus nanofiber membrane (NFM) by adding the as-prepared magnetic CoFe2O4 nanoparticles into the polyacrylonitrile (PAN) side (m-PAN) and the fluorescent molecules of 1,8-naphthalene anhydride (1,8-NAD) into the polyvinylpyrrolidone (PVP) side (f-PVP) via electrospinning method. The obtained m-PAN/f-PVP Janus NFM exhibited excellent magnetic performance and high fluorescent properties due to the unique structure. Compared with the m-PAN/f-PVP composite NFM, the Janus NFM showed higher fluorescent performance because the fluorescent molecules were isolated from the magnetic nanoparticles. In addition, the Janus NFM not only maintain the good self-supporting state in water but also realize a directional movement attracted by a magnet. The unique structure of Janus nanofiber is of great importance and demonstrates great potential applications.
Fang, Teng; Zhao, Xinbing; Zhu, Tiejun
2018-05-19
Half-Heusler (HH) compounds, with a valence electron count of 8 or 18, have gained popularity as promising high-temperature thermoelectric (TE) materials due to their excellent electrical properties, robust mechanical capabilities, and good high-temperature thermal stability. With the help of first-principles calculations, great progress has been made in half-Heusler thermoelectric materials. In this review, we summarize some representative theoretical work on band structures and transport properties of HH compounds. We introduce how basic band-structure calculations are used to investigate the atomic disorder in n-type M NiSb ( M = Ti, Zr, Hf) compounds and guide the band engineering to enhance TE performance in p-type Fe R Sb ( R = V, Nb) based systems. The calculations on electrical transport properties, especially the scattering time, and lattice thermal conductivities are also demonstrated. The outlook for future research directions of first-principles calculations on HH TE materials is also discussed.
An Effective Electrical Resonance-Based Method to Detect Delamination in Thermal Barrier Coating
NASA Astrophysics Data System (ADS)
Kim, Jong Min; Park, Jae-Ha; Lee, Ho Girl; Kim, Hak-Joon; Song, Sung-Jin; Seok, Chang-Sung; Lee, Young-Ze
2017-12-01
This research proposes a simple yet highly sensitive method based on electrical resonance of an eddy-current probe to detect delamination of thermal barrier coating (TBC). This method can directly measure the mechanical characteristics of TBC compared to conventional ultrasonic testing and infrared thermography methods. The electrical resonance-based method can detect the delamination of TBC from the metallic bond coat by shifting the electrical impedance of eddy current testing (ECT) probe coupling with degraded TBC, and, due to this shift, the resonant frequencies near the peak impedance of ECT probe revealed high sensitivity to the delamination. In order to verify the performance of the proposed method, a simple experiment is performed with degraded TBC specimens by thermal cyclic exposure. Consequently, the delamination with growth of thermally grown oxide in a TBC system is experimentally identified. Additionally, the results are in good agreement with the results obtained from ultrasonic C-scanning.
An Effective Electrical Resonance-Based Method to Detect Delamination in Thermal Barrier Coating
NASA Astrophysics Data System (ADS)
Kim, Jong Min; Park, Jae-Ha; Lee, Ho Girl; Kim, Hak-Joon; Song, Sung-Jin; Seok, Chang-Sung; Lee, Young-Ze
2018-02-01
This research proposes a simple yet highly sensitive method based on electrical resonance of an eddy-current probe to detect delamination of thermal barrier coating (TBC). This method can directly measure the mechanical characteristics of TBC compared to conventional ultrasonic testing and infrared thermography methods. The electrical resonance-based method can detect the delamination of TBC from the metallic bond coat by shifting the electrical impedance of eddy current testing (ECT) probe coupling with degraded TBC, and, due to this shift, the resonant frequencies near the peak impedance of ECT probe revealed high sensitivity to the delamination. In order to verify the performance of the proposed method, a simple experiment is performed with degraded TBC specimens by thermal cyclic exposure. Consequently, the delamination with growth of thermally grown oxide in a TBC system is experimentally identified. Additionally, the results are in good agreement with the results obtained from ultrasonic C-scanning.