Safety in surgery: is selection the missing link?

PubMed

Paice, Alistair G; Aggarwal, Rajesh; Darzi, Ara

2010-09-01

Health care providers comprise an example of a "high risk organization." Safety failings within these organizations have the potential to cause significant public harm. Significant safety improvements in other high risk organizations such as the aviation industry have led to the concept of a high reliability organization (HRO)--a high risk organization that has enjoyed a prolonged safety record. A strong organizational culture is common to all successful HROs, encompassing powerful systems of selection and training. Aircrew selection processes provide a good example of this and are examined in detail in this article using the Royal Air Force process as an example. If the lessons of successful HROs are to be applied to health care organizations, candidate selection to specialties such as surgery must become more objective and robust. Other HROs can provide valuable lessons in how this may be approached.

Microalgal process-monitoring based on high-selectivity spectroscopy tools: status and future perspectives.

PubMed

Podevin, Michael; Fotidis, Ioannis A; Angelidaki, Irini

2018-08-01

Microalgae are well known for their ability to accumulate lipids intracellularly, which can be used for biofuels and mitigate CO 2 emissions. However, due to economic challenges, microalgae bioprocesses have maneuvered towards the simultaneous production of food, feed, fuel, and various high-value chemicals in a biorefinery concept. On-line and in-line monitoring of macromolecules such as lipids, proteins, carbohydrates, and high-value pigments will be more critical to maintain product quality and consistency for downstream processing in a biorefinery to maintain and valorize these markets. The main contribution of this review is to present current and prospective advances of on-line and in-line process analytical technology (PAT), with high-selectivity - the capability of monitoring several analytes simultaneously - in the interest of improving product quality, productivity, and process automation of a microalgal biorefinery. The high-selectivity PAT under consideration are mid-infrared (MIR), near-infrared (NIR), and Raman vibrational spectroscopies. The current review contains a critical assessment of these technologies in the context of recent advances in software and hardware in order to move microalgae production towards process automation through multivariate process control (MVPC) and software sensors trained on "big data". The paper will also include a comprehensive overview of off-line implementations of vibrational spectroscopy in microalgal research as it pertains to spectral interpretation and process automation to aid and motivate development.

Scheduler for multiprocessor system switch with selective pairing

DOEpatents

Gara, Alan; Gschwind, Michael Karl; Salapura, Valentina

2015-01-06

System, method and computer program product for scheduling threads in a multiprocessing system with selective pairing of processor cores for increased processing reliability. A selective pairing facility is provided that selectively connects, i.e., pairs, multiple microprocessor or processor cores to provide one highly reliable thread (or thread group). The method configures the selective pairing facility to use checking provide one highly reliable thread for high-reliability and allocate threads to corresponding processor cores indicating need for hardware checking. The method configures the selective pairing facility to provide multiple independent cores and allocate threads to corresponding processor cores indicating inherent resilience.

Study for identification of Beneficial Uses of Space (BUS). Volume 2: Technical report. Book 1: Sections 1 through 4. [with emphasis on space manufacturing and product development

NASA Technical Reports Server (NTRS)

1973-01-01

Consolidated information is presented for the study whose purpose was to identify products, processes, and services to be produced in future spacecraft environments for direct utilization on earth. Discussion of methodology for selecting from among potential space processing approaches, definition of requirements for experiments and tests needed to acquire sufficient knowledge for proof testing of selected processes, formulation of research and development schedules to achieve proof testing, and documentation of the decision processes involved in the programs are presented. Technology and programmatics are reported for the following select studies: (1) surface acoustic wave components; (2) transparent oxides; (3) high purity tungsten X-ray targets; and (4) high specificity isoenzymes.

Selective dry etching of silicon containing anti-reflective coating

NASA Astrophysics Data System (ADS)

Sridhar, Shyam; Nolan, Andrew; Wang, Li; Karakas, Erdinc; Voronin, Sergey; Biolsi, Peter; Ranjan, Alok

2018-03-01

Multi-layer patterning schemes involve the use of Silicon containing Anti-Reflective Coating (SiARC) films for their anti-reflective properties. Patterning transfer completion requires complete and selective removal of SiARC which is very difficult due to its high silicon content (>40%). Typically, SiARC removal is accomplished through a non-selective etch during the pattern transfer process using fluorine containing plasmas, or an ex-situ wet etch process using hydrofluoric acid is employed to remove the residual SiARC, post pattern transfer. Using a non-selective etch may result in profile distortion or wiggling, due to distortion of the underlying organic layer. The drawbacks of using wet etch process for SiARC removal are increased overall processing time and the need for additional equipment. Many applications may involve patterning of active structures in a poly-Si layer with an underlying oxide stopping layer. In such applications, SiARC removal selective to oxide using a wet process may prove futile. Removing SiARC selectively to SiO2 using a dry etch process is also challenging, due to similarity in the nature of chemical bonds (Si - O) in the two materials. In this work, we present highly selective etching of SiARC, in a plasma driven by a surface wave radial line slot antenna. The first step in the process involves an in-situ modification of the SiARC layer in O2 plasma followed by selective etching in a NF3/H2 plasma. Surface treatment in O2 plasma resulted in enhanced etching of the SiARC layer. For the right processing conditions, in-situ NF3/H2 dry etch process demonstrated selectivity values greater than 15:1 with respect to SiO2. The etching chemistry, however, was sensitive to NF3:H2 gas ratio. For dilute NF3 in H2, no SiARC etching was observed. Presumably, this is due to the deposition of ammonium fluorosilicate layer that occurs for dilute NF3/H2 plasmas. Additionally, challenges involved in selective SiARC removal (selective to SiO2, organic and Si layers) post pattern transfer, in a multi-layer structure will be discussed.

Distracted and confused?: selective attention under load.

PubMed

Lavie, Nilli

2005-02-01

The ability to remain focused on goal-relevant stimuli in the presence of potentially interfering distractors is crucial for any coherent cognitive function. However, simply instructing people to ignore goal-irrelevant stimuli is not sufficient for preventing their processing. Recent research reveals that distractor processing depends critically on the level and type of load involved in the processing of goal-relevant information. Whereas high perceptual load can eliminate distractor processing, high load on "frontal" cognitive control processes increases distractor processing. These findings provide a resolution to the long-standing early and late selection debate within a load theory of attention that accommodates behavioural and neuroimaging data within a framework that integrates attention research with executive function.

Dry-plasma-free chemical etch technique for variability reduction in multi-patterning (Conference Presentation)

NASA Astrophysics Data System (ADS)

Kal, Subhadeep; Mohanty, Nihar; Farrell, Richard A.; Franke, Elliott; Raley, Angelique; Thibaut, Sophie; Pereira, Cheryl; Pillai, Karthik; Ko, Akiteru; Mosden, Aelan; Biolsi, Peter

2017-04-01

Scaling beyond the 7nm technology node demands significant control over the variability down to a few angstroms, in order to achieve reasonable yield. For example, to meet the current scaling targets it is highly desirable to achieve sub 30nm pitch line/space features at back-end of the line (BEOL) or front end of line (FEOL); uniform and precise contact/hole patterning at middle of line (MOL). One of the quintessential requirements for such precise and possibly self-aligned patterning strategies is superior etch selectivity between the target films while other masks/films are exposed. The need to achieve high etch selectivity becomes more evident for unit process development at MOL and BEOL, as a result of low density films choices (compared to FEOL film choices) due to lower temperature budget. Low etch selectivity with conventional plasma and wet chemical etch techniques, causes significant gouging (un-intended etching of etch stop layer, as shown in Fig 1), high line edge roughness (LER)/line width roughness (LWR), non-uniformity, etc. In certain circumstances this may lead to added downstream process stochastics. Furthermore, conventional plasma etches may also have the added disadvantage of plasma VUV damage and corner rounding (Fig. 1). Finally, the above mentioned factors can potentially compromise edge placement error (EPE) and/or yield. Therefore a process flow enabled with extremely high selective etches inherent to film properties and/or etch chemistries is a significant advantage. To improve this etch selectivity for certain etch steps during a process flow, we have to implement alternate highly selective, plasma free techniques in conjunction with conventional plasma etches (Fig 2.). In this article, we will present our plasma free, chemical gas phase etch technique using chemistries that have high selectivity towards a spectrum of films owing to the reaction mechanism ( as shown Fig 1). Gas phase etches also help eliminate plasma damage to the features during the etch process. Herein we will also demonstrate a test case on how a combination or plasma assisted and plasma free etch techniques has the potential to improve process performance of a 193nm immersion based self aligned quandruple patterning (SAQP) for BEOL compliant films (an example shown in Fig 2). In addition, we will also present on the application of gas etches for (1) profile improvement, (2) selective mandrel pull (3) critical dimension trim of mandrels, with an analysis of advantages over conventional techniques in terms of LER and EPE.

Selective epitaxy using the gild process

DOEpatents

Weiner, Kurt H.

1992-01-01

The present invention comprises a method of selective epitaxy on a semiconductor substrate. The present invention provides a method of selectively forming high quality, thin GeSi layers in a silicon circuit, and a method for fabricating smaller semiconductor chips with a greater yield (more error free chips) at a lower cost. The method comprises forming an upper layer over a substrate, and depositing a reflectivity mask which is then removed over selected sections. Using a laser to melt the unmasked sections of the upper layer, the semiconductor material in the upper layer is heated and diffused into the substrate semiconductor material. By varying the amount of laser radiation, the epitaxial layer is formed to a controlled depth which may be very thin. When cooled, a single crystal epitaxial layer is formed over the patterned substrate. The present invention provides the ability to selectively grow layers of mixed semiconductors over patterned substrates such as a layer of Ge.sub.x Si.sub.1-x grown over silicon. Such a process may be used to manufacture small transistors that have a narrow base, heavy doping, and high gain. The narrowness allows a faster transistor, and the heavy doping reduces the resistance of the narrow layer. The process does not require high temperature annealing; therefore materials such as aluminum can be used. Furthermore, the process may be used to fabricate diodes that have a high reverse breakdown voltage and a low reverse leakage current.

Load theory of selective attention and cognitive control.

PubMed

Lavie, Nilli; Hirst, Aleksandra; de Fockert, Jan W; Viding, Essi

2004-09-01

A load theory of attention in which distractor rejection depends on the level and type of load involved in current processing was tested. A series of experiments demonstrates that whereas high perceptual load reduces distractor interference, working memory load or dual-task coordination load increases distractor interference. These findings suggest 2 selective attention mechanisms: a perceptual selection mechanism serving to reduce distractor perception in situations of high perceptual load that exhaust perceptual capacity in processing relevant stimuli and a cognitive control mechanism that reduces interference from perceived distractors as long as cognitive control functions are available to maintain current priorities (low cognitive load). This theory resolves the long-standing early versus late selection debate and clarifies the role of cognitive control in selective attention. ((c) 2004 APA, all rights reserved)

Dehydration processes using membranes with hydrophobic coating

DOEpatents

Huang, Yu; Baker, Richard W; Aldajani, Tiem; Ly, Jennifer

2013-07-30

Processes for removing water from organic compounds, especially polar compounds such as alcohols. The processes include a membrane-based dehydration step, using a membrane that has a dioxole-based polymer selective layer or the like and a hydrophilic selective layer, and can operate even when the stream to be treated has a high water content, such as 10 wt % or more. The processes are particularly useful for dehydrating ethanol.

Multiprocessor switch with selective pairing

DOEpatents

Gara, Alan; Gschwind, Michael K; Salapura, Valentina

2014-03-11

System, method and computer program product for a multiprocessing system to offer selective pairing of processor cores for increased processing reliability. A selective pairing facility is provided that selectively connects, i.e., pairs, multiple microprocessor or processor cores to provide one highly reliable thread (or thread group). Each paired microprocessor or processor cores that provide one highly reliable thread for high-reliability connect with a system components such as a memory "nest" (or memory hierarchy), an optional system controller, and optional interrupt controller, optional I/O or peripheral devices, etc. The memory nest is attached to a selective pairing facility via a switch or a bus

Nonequivalence of updating rules in evolutionary games under high mutation rates.

PubMed

Kaiping, G A; Jacobs, G S; Cox, S J; Sluckin, T J

2014-10-01

Moran processes are often used to model selection in evolutionary simulations. The updating rule in Moran processes is a birth-death process, i. e., selection according to fitness of an individual to give birth, followed by the death of a random individual. For well-mixed populations with only two strategies this updating rule is known to be equivalent to selecting unfit individuals for death and then selecting randomly for procreation (biased death-birth process). It is, however, known that this equivalence does not hold when considering structured populations. Here we study whether changing the updating rule can also have an effect in well-mixed populations in the presence of more than two strategies and high mutation rates. We find, using three models from different areas of evolutionary simulation, that the choice of updating rule can change model results. We show, e. g., that going from the birth-death process to the death-birth process can change a public goods game with punishment from containing mostly defectors to having a majority of cooperative strategies. From the examples given we derive guidelines indicating when the choice of the updating rule can be expected to have an impact on the results of the model.

Nonequivalence of updating rules in evolutionary games under high mutation rates

NASA Astrophysics Data System (ADS)

Kaiping, G. A.; Jacobs, G. S.; Cox, S. J.; Sluckin, T. J.

2014-10-01

Moran processes are often used to model selection in evolutionary simulations. The updating rule in Moran processes is a birth-death process, i. e., selection according to fitness of an individual to give birth, followed by the death of a random individual. For well-mixed populations with only two strategies this updating rule is known to be equivalent to selecting unfit individuals for death and then selecting randomly for procreation (biased death-birth process). It is, however, known that this equivalence does not hold when considering structured populations. Here we study whether changing the updating rule can also have an effect in well-mixed populations in the presence of more than two strategies and high mutation rates. We find, using three models from different areas of evolutionary simulation, that the choice of updating rule can change model results. We show, e. g., that going from the birth-death process to the death-birth process can change a public goods game with punishment from containing mostly defectors to having a majority of cooperative strategies. From the examples given we derive guidelines indicating when the choice of the updating rule can be expected to have an impact on the results of the model.

Attentional selection of relative SF mediates global versus local processing: evidence from EEG.

PubMed

Flevaris, Anastasia V; Bentin, Shlomo; Robertson, Lynn C

2011-06-13

Previous research on functional hemispheric differences in visual processing has associated global perception with low spatial frequency (LSF) processing biases of the right hemisphere (RH) and local perception with high spatial frequency (HSF) processing biases of the left hemisphere (LH). The Double Filtering by Frequency (DFF) theory expanded this hypothesis by proposing that visual attention selects and is directed to relatively LSFs by the RH and relatively HSFs by the LH, suggesting a direct causal relationship between SF selection and global versus local perception. We tested this idea in the current experiment by comparing activity in the EEG recorded at posterior right and posterior left hemisphere sites while participants' attention was directed to global or local levels of processing after selection of relatively LSFs versus HSFs in a previous stimulus. Hemispheric asymmetry in the alpha band (8-12 Hz) during preparation for global versus local processing was modulated by the selected SF. In contrast, preparatory activity associated with selection of SF was not modulated by the previously attended level (global/local). These results support the DFF theory that top-down attentional selection of SF mediates global and local processing.

Attention to Hierarchical Level Influences Attentional Selection of Spatial Scale

ERIC Educational Resources Information Center

Flevaris, Anastasia V.; Bentin, Shlomo; Robertson, Lynn C.

2011-01-01

Ample evidence suggests that global perception may involve low spatial frequency (LSF) processing and that local perception may involve high spatial frequency (HSF) processing (Shulman, Sullivan, Gish, & Sakoda, 1986; Shulman & Wilson, 1987; Robertson, 1996). It is debated whether SF selection is a low-level mechanism associating global…

Selective laser melting of Inconel super alloy-a review

NASA Astrophysics Data System (ADS)

Karia, M. C.; Popat, M. A.; Sangani, K. B.

2017-07-01

Additive manufacturing is a relatively young technology that uses the principle of layer by layer addition of material in solid, liquid or powder form to develop a component or product. The quality of additive manufactured part is one of the challenges to be addressed. Researchers are continuously working at various levels of additive manufacturing technologies. One of the significant powder bed processes for met als is Selective Laser Melting (SLM). Laser based processes are finding more attention of researchers and industrial world. The potential of this technique is yet to be fully explored. Due to very high strength and creep resistance Inconel is extensively used nickel based super alloy for manufacturing components for aerospace, automobile and nuclear industries. Due to law content of Aluminum and Titanium, it exhibits good fabricability too. Therefore the alloy is ideally suitable for selective laser melting to manufacture intricate components with high strength requirements. The selection of suitable process for manufacturing for a specific component depends on geometrical complexity, production quantity, and cost and required strength. There are numerous researchers working on various aspects like metallurgical and micro structural investigations and mechanical properties, geometrical accuracy, effects of process parameters and its optimization and mathematical modeling etc. The present paper represents a comprehensive overview of selective laser melting process for Inconel group of alloys.

Working memory load can both improve and impair selective attention: evidence from the Navon paradigm.

PubMed

Ahmed, Lubna; de Fockert, Jan W

2012-10-01

Selective attention to relevant targets has been shown to depend on the availability of working memory (WM). Under conditions of high WM load, processing of irrelevant distractors is enhanced. Here we showed that this detrimental effect of WM load on selective attention efficiency is reversed when the task requires global- rather than local-level processing. Participants were asked to attend to either the local or the global level of a hierarchical Navon stimulus while keeping either a low or a high load in WM. In line with previous findings, during attention to the local level, distractors at the global level produced more interference under high than under low WM load. By contrast, loading WM had the opposite effect of improving selective attention during attention to the global level. The findings demonstrate that the impact of WM load on selective attention is not invariant, but rather is dependent on the level of the to-be-attended information.

A fast, programmable hardware architecture for spaceborne SAR processing

NASA Technical Reports Server (NTRS)

Bennett, J. R.; Cumming, I. G.; Lim, J.; Wedding, R. M.

1983-01-01

The launch of spaceborne SARs during the 1980's is discussed. The satellite SARs require high quality and high throughput ground processors. Compression ratios in range and azimuth of greater than 500 and 150 respectively lead to frequency domain processing and data computation rates in excess of 2000 million real operations per second for C-band SARs under consideration. Various hardware architectures are examined and two promising candidates and proceeds to recommend a fast, programmable hardware architecture for spaceborne SAR processing are selected. Modularity and programmability are introduced as desirable attributes for the purpose of HTSP hardware selection.

Effects of high-dose ethanol intoxication and hangover on cognitive flexibility.

PubMed

Wolff, Nicole; Gussek, Philipp; Stock, Ann-Kathrin; Beste, Christian

2018-01-01

The effects of high-dose ethanol intoxication on cognitive flexibility processes are not well understood, and processes related to hangover after intoxication have remained even more elusive. Similarly, it is unknown in how far the complexity of cognitive flexibility processes is affected by intoxication and hangover effects. We performed a neurophysiological study applying high density electroencephalography (EEG) recording to analyze event-related potentials (ERPs) and perform source localization in a task switching paradigm which varied the complexity of task switching by means of memory demands. The results show that high-dose ethanol intoxication only affects task switching (i.e. cognitive flexibility processes) when memory processes are required to control task switching mechanisms, suggesting that even high doses of ethanol compromise cognitive processes when they are highly demanding. The EEG and source localization data show that these effects unfold by modulating response selection processes in the anterior cingulate cortex. Perceptual and attentional selection processes as well as working memory processes were only unspecifically modulated. In all subprocesses examined, there were no differences between the sober and hangover states, thus suggesting a fast recovery of cognitive flexibility after high-dose ethanol intoxication. We assume that the gamma-aminobutyric acid (GABAergic) system accounts for the observed effects, while they can hardly be explained by the dopaminergic system. © 2016 Society for the Study of Addiction.

Development of Advanced Nuclide Separation and Recovery Methods using Ion-Exchanhge Techniques in Nuclear Backend

NASA Astrophysics Data System (ADS)

Miura, Hitoshi

The development of compact separation and recovery methods using selective ion-exchange techniques is very important for the reprocessing and high-level liquid wastes (HLLWs) treatment in the nuclear backend field. The selective nuclide separation techniques are effective for the volume reduction of wastes and the utilization of valuable nuclides, and expected for the construction of advanced nuclear fuel cycle system and the rationalization of waste treatment. In order to accomplish the selective nuclide separation, the design and synthesis of novel adsorbents are essential for the development of compact and precise separation processes. The present paper deals with the preparation of highly functional and selective hybrid microcapsules enclosing nano-adsorbents in the alginate gel polymer matrices by sol-gel methods, their characterization and the clarification of selective adsorption properties by batch and column methods. The selective separation of Cs, Pd and Re in real HLLW was further accomplished by using novel microcapsules, and an advanced nuclide separation system was proposed by the combination of selective processes using microcapsules.

High-Performance Substrates for SERS Detection via Microphotonic Photopolymer Characterization and Coating With Functionalized Hydrogels

DTIC Science & Technology

2006-11-26

with controlled micro and nanostructure for highly selective, high sensitivity assays. The process was modeled and a procedure for fabricating SERS...small volumes with controlled micro and nanostructure for highly selective, high sensitivity assays. We proved the feasibility of the technique and...films templated by colloidal crystals. The control over the film structure allowed optimizing their performance for potential sensor applications. The

Crystallization and doping of amorphous silicon on low temperature plastic

DOEpatents

Kaschmitter, James L.; Truher, Joel B.; Weiner, Kurt H.; Sigmon, Thomas W.

1994-01-01

A method or process of crystallizing and doping amorphous silicon (a-Si) on a low-temperature plastic substrate using a short pulsed high energy source in a selected environment, without heat propagation and build-up in the substrate. The pulsed energy processing of the a-Si in a selected environment, such as BF3 and PF5, will form a doped micro-crystalline or poly-crystalline silicon (pc-Si) region or junction point with improved mobilities, lifetimes and drift and diffusion lengths and with reduced resistivity. The advantage of this method or process is that it provides for high energy materials processing on low cost, low temperature, transparent plastic substrates. Using pulsed laser processing a high (>900.degree. C.), localized processing temperature can be achieved in thin films, with little accompanying temperature rise in the substrate, since substrate temperatures do not exceed 180.degree. C. for more than a few microseconds. This method enables use of plastics incapable of withstanding sustained processing temperatures (higher than 180.degree. C.) but which are much lower cost, have high tolerance to ultraviolet light, have high strength and good transparency, compared to higher temperature plastics such as polyimide.

Crystallization and doping of amorphous silicon on low temperature plastic

DOEpatents

Kaschmitter, J.L.; Truher, J.B.; Weiner, K.H.; Sigmon, T.W.

1994-09-13

A method or process of crystallizing and doping amorphous silicon (a-Si) on a low-temperature plastic substrate using a short pulsed high energy source in a selected environment, without heat propagation and build-up in the substrate is disclosed. The pulsed energy processing of the a-Si in a selected environment, such as BF3 and PF5, will form a doped micro-crystalline or poly-crystalline silicon (pc-Si) region or junction point with improved mobilities, lifetimes and drift and diffusion lengths and with reduced resistivity. The advantage of this method or process is that it provides for high energy materials processing on low cost, low temperature, transparent plastic substrates. Using pulsed laser processing a high (>900 C), localized processing temperature can be achieved in thin films, with little accompanying temperature rise in the substrate, since substrate temperatures do not exceed 180 C for more than a few microseconds. This method enables use of plastics incapable of withstanding sustained processing temperatures (higher than 180 C) but which are much lower cost, have high tolerance to ultraviolet light, have high strength and good transparency, compared to higher temperature plastics such as polyimide. 5 figs.

Process for the conversion of lower alcohols to higher branched oxygenates

DOEpatents

Barger, Paul T.

1996-01-01

A process is provided for the production of branched C.sub.4+ oxygenates from lower alcohols such as methanol, ethanol, propanol and mixtures thereof. The process comprises contacting the lower alcohols with a solid catalyst comprising a mixed metal oxide support having components selected from the group consisting of oxides of zinc, magnesium, zirconia, titanium, manganese, chromium, and lanthanides, and an activation metal selected from the group consisting of Group VIII metal, Group IB metals, and mixtures thereof. The advantage of the process is improved yields and selectivity to isobutanol which can subsequently be employed in the production of high octane motor gasoline.

Process for the conversion of lower alcohols to higher branched oxygenates

DOEpatents

Barger, P.T.

1996-09-24

A process is provided for the production of branched C{sub x} oxygenates from lower alcohols such as methanol, ethanol, propanol and mixtures thereof. The process comprises contacting the lower alcohols with a solid catalyst comprising a mixed metal oxide support having components selected from the group consisting of oxides of zinc, magnesium, zirconia, titanium, manganese, chromium, and lanthanides, and an activation metal selected from the group consisting of Group VIII metal, Group IB metals, and mixtures thereof. The advantage of the process is improved yields and selectivity to isobutanol which can subsequently be employed in the production of high octane motor gasoline.

Selective deposition of a crystalline Si film by a chemical sputtering process in a high pressure hydrogen plasma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ohmi, Hiromasa, E-mail: ohmi@prec.eng.osaka-u.ac.jp; Yasutake, Kiyoshi; Research Center for Ultra-Precision Science and Technology, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871

2015-07-28

The selective deposition of Si films was demonstrated using a chemical sputtering process induced by a high pressure hydrogen plasma at 52.6 kPa (400 Torr). In this chemical sputtering process, the initial deposition rate (R{sub d}) is dependent upon the substrate type. At the initial stage of Si film formation, R{sub d} on glass substrates increased with elapsed time and reached to a constant value. In contrast, R{sub d} on Si substrates remained constant during the deposition. The selective deposition of Si films can be achieved by adjusting the substrate temperature (T{sub sub}) and hydrogen concentration (C{sub H2}) in the process atmosphere.more » For any given deposition time, it was found that an optimum C{sub H2} exists for a given T{sub sub} to realize the selective deposition of a Si film, and the optimum T{sub sub} value tends to increase with decreasing C{sub H2}. According to electron diffraction patterns obtained from the samples, the selectively prepared Si films showed epitaxial-like growth, although the Si films contained many defects. It was revealed by Raman scattering spectroscopy that some of the defects in the Si films were platelet defects induced by excess hydrogen incorporated during Si film formation. Raman spectrum also suggested that Si related radicals (SiH{sub 2}, SiH, Si) with high reactivity contribute to the Si film formation. Simple model was derived as the guideline for achieving the selective growth.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Disselkamp, Robert S.; Chajkowski, Sarah M.; Boyles, Kelly R.

Here we discuss results obtained as part of a three-year investigation at Pacific Northwest National Laboratory of ultrasound processing to effect selectivity and activity in the hydrogenation of water-soluble olefins on transition metal catalysts. We have shown previously that of the two regimes for ultrasound processing, high-power cavitating and high-power non-cavitating, only the former can effect product selectivity dramatically (> 1000%) whereas the selectivity of the latter was comparable with those obtained in stirred/silent control experiments [R.S. Disselkamp, Y.-H. Chin, C.H.F. Peden, J. Catal., 227, 552 (2005)]. As a means of ensuring the benefits of cavitating ultrasound processing, we introducedmore » the concept of employing inert dopants into the reacting solution. These inert dopants do not partake in solution chemistry but enable a more facile transition from high-power non-cavitating to cavitating conditions during sonication treatment. With cavitation processing conditions ensured, we discuss here results of isotopic H/D substitution for a variety of substrates and illustrate how such isotope dependent chemistries during substrate hydrogenation elucidate detailed mechanistic information about these reaction systems.« less

Selective sequential precipitation of dissolved metals in mine drainage from coal mine

NASA Astrophysics Data System (ADS)

Yim, Giljae; Bok, Songmin; Ji, Sangwoo; Oh, Chamteut; Cheong, Youngwook; Han, Youngsoo; Ahn, Joosung

2017-04-01

In abandoned mines in Korea, a large amount of mine drainage continues to flow out and spread pollution. In purification of the mine drainage a massive amount of sludge is generated as waste. Since this metal sludge contains high Fe, Al and Mn oxides, developing the treatment method to recover homogeneous individual metal with high purity may beneficial to recycle waste metals as useful resources and reduce the amount of sludge production. In this regard, we established a dissolved metals selective precipitation process to treat Waryong Industry's mine drainage. The process that selectively precipitates metals dissolved in mine drainage is a continuous Fe-buffer-Al process, and each process consists of the neutralization tank, the coagulation tank, and the settling tank. Based on this process, this study verified the operational applicability of the Fe and Al selective precipitation. Our previous study revealed that high-purity Fe and Al precipitates could be recovered at a flow rate of 1.5 ton/day, while the lower purity was achieved when the rate was increased to about 3 ton/day due to the difficulty in reagent dosage control. In the current study was conducted to increase the capacity of the system to recover Fe and Al as high-purity precipitates at a flow rate of 10 ton/day with the ensured continuous operations by introducing an automatic reagent injection system. The previous study had a difficulty in controlling the pH and operating system continuously due to the manually controlled reagent injection system. To upgrade this and ensure the optimal pH in a stable way, a continuous reagent injection system was installed. The result of operation of the 10 ton/day system confirmed that the scaled-up process could maintain the stable recovery rates and purities of precipitates on site.

Effect of enzyme activity on the starch structure and processing quality of selected rice varieties

USDA-ARS?s Scientific Manuscript database

Although most commercialized long grain rice varieties have intermediate amylose content (~22%), high amylose (>25%) varieties are important for the canning and parboiling industry. Research has shown that high amylose rice varieties that have the best processing quality have high setback and low br...

False memory and importance: can we prioritize encoding without consequence?

PubMed

Bui, Dung C; Friedman, Michael C; McDonough, Ian M; Castel, Alan D

2013-10-01

Given the large amount of information that we encounter, we often must prioritize what information we attempt to remember. Although critical for everyday functioning, relatively little research has focused on how people prioritize the encoding of information. Recent research has shown that people can and do selectively remember information assigned with higher, relative to lower, importance. However, the mechanisms underlying this prioritization process and the consequences of these processes are still not well understood. In the present study, we sought to better understand these prioritization processes and whether implementing these processes comes at the cost of memory accuracy, by increasing false memories. We used a modified form of the Deese/Roediger-McDermott (DRM) paradigm, in which participants studied DRM lists, with each list paired with low, medium, or high point values. In Experiment 1, encoding higher values led to more false memories than did encoding lower values, possibly because prioritizing information enhanced relational processing among high-value words. In Experiment 2, disrupting relational processing selectively reduced false memories for high-value words. Finally, in Experiment 3, facilitating relational processing selectively increased false memories for low-value words. These findings suggest that while prioritizing information can enhance true memory, this process concomitantly increases false memories. Furthermore, the mechanism underlying these prioritization processes depends on the ability to successfully engage in relational processing. Thus, how we prioritize the encoding of incoming information can come at a cost in terms of accurate memory.

Listeners modulate temporally selective attention during natural speech processing

PubMed Central

Astheimer, Lori B.; Sanders, Lisa D.

2009-01-01

Spatially selective attention allows for the preferential processing of relevant stimuli when more information than can be processed in detail is presented simultaneously at distinct locations. Temporally selective attention may serve a similar function during speech perception by allowing listeners to allocate attentional resources to time windows that contain highly relevant acoustic information. To test this hypothesis, event-related potentials were compared in response to attention probes presented in six conditions during a narrative: concurrently with word onsets, beginning 50 and 100 ms before and after word onsets, and at random control intervals. Times for probe presentation were selected such that the acoustic environments of the narrative were matched for all conditions. Linguistic attention probes presented at and immediately following word onsets elicited larger amplitude N1s than control probes over medial and anterior regions. These results indicate that native speakers selectively process sounds presented at specific times during normal speech perception. PMID:18395316

Molecular basis of cyclooxygenase enzymes (COXs) selective inhibition

PubMed Central

Limongelli, Vittorio; Bonomi, Massimiliano; Marinelli, Luciana; Gervasio, Francesco Luigi; Cavalli, Andrea; Novellino, Ettore; Parrinello, Michele

2010-01-01

The widely used nonsteroidal anti-inflammatory drugs block the cyclooxygenase enzymes (COXs) and are clinically used for the treatment of inflammation, pain, and cancers. A selective inhibition of the different isoforms, particularly COX-2, is desirable, and consequently a deeper understanding of the molecular basis of selective inhibition is of great demand. Using an advanced computational technique we have simulated the full dissociation process of a highly potent and selective inhibitor, SC-558, in both COX-1 and COX-2. We have found a previously unreported alternative binding mode in COX-2 explaining the time-dependent inhibition exhibited by this class of inhibitors and consequently their long residence time inside this isoform. Our metadynamics-based approach allows us to illuminate the highly dynamical character of the ligand/protein recognition process, thus explaining a wealth of experimental data and paving the way to an innovative strategy for designing new COX inhibitors with tuned selectivity. PMID:20215464

Dissociating the Influence of Response Selection and Task Anticipation on Corticospinal Suppression During Response Preparation

PubMed Central

Duque, Julie; Labruna, Ludovica; Cazares, Christian; Ivry, Richard B.

2014-01-01

Motor behavior requires selecting between potential actions. The role of inhibition in response selection has frequently been examined in tasks in which participants are engaged in some advance preparation prior to the presentation of an imperative signal. Under such conditions, inhibition could be related to processes associated with response selection, or to more general inhibitory processes that are engaged in high states of anticipation. In Experiment 1, we manipulated the degree of anticipatory preparation. Participants performed a choice reaction time task that required choosing between a movement of the left or right index finger, and used transcranial magnetic stimulation (TMS) to elicit motor evoked potentials (MEPs) in the left hand agonist. In high anticipation blocks, a non-informative cue (e.g., fixation marker) preceded the imperative; in low anticipation blocks, there was no cue and participants were required to divide their attention between two tasks to further reduce anticipation. MEPs were substantially reduced before the imperative signal in high anticipation blocks. In contrast, in low anticipation blocks, MEPs remained unchanged before the imperative signal but showed a marked suppression right after the onset of the imperative. This effect occurred regardless of whether the imperative had signaled a left or right hand response. After this initial inhibition, left MEPs increased when the left hand was selected and remained suppressed when the right hand was selected. We obtained similar results in Experiment 2 except that the persistent left MEP suppression when the left hand was not selected was attenuated when the alternative response involved a non-homologous effector (right foot). These results indicate that, even in the absence of an anticipatory period, inhibitory mechanisms are engaged during response selection, possibly to prevent the occurrence of premature and inappropriate responses during a competitive selection process. PMID:25128431

A theory of germinal center B cell selection, division, and exit.

PubMed

Meyer-Hermann, Michael; Mohr, Elodie; Pelletier, Nadége; Zhang, Yang; Victora, Gabriel D; Toellner, Kai-Michael

2012-07-26

High-affinity antibodies are generated in germinal centers in a process involving mutation and selection of B cells. Information processing in germinal center reactions has been investigated in a number of recent experiments. These have revealed cell migration patterns, asymmetric cell divisions, and cell-cell interaction characteristics, used here to develop a theory of germinal center B cell selection, division, and exit (the LEDA model). According to this model, B cells selected by T follicular helper cells on the basis of successful antigen processing always return to the dark zone for asymmetric division, and acquired antigen is inherited by one daughter cell only. Antigen-retaining B cells differentiate to plasma cells and leave the germinal center through the dark zone. This theory has implications for the functioning of germinal centers because compared to previous models, high-affinity antibodies appear one day earlier and the amount of derived plasma cells is considerably larger. Copyright © 2012 The Authors. Published by Elsevier Inc. All rights reserved.

Effects of aging on value-directed modulation of semantic network activity during verbal learning

PubMed Central

Cohen, Michael S.; Rissman, Jesse; Suthana, Nanthia A.; Castel, Alan D.; Knowlton, Barbara J.

2015-01-01

While impairments in memory recall are apparent in aging, older adults show a remarkably preserved ability to selectively remember information deemed valuable. Here, we use fMRI to compare brain activation in healthy older and younger adults during encoding of high and low value words to determine whether there are differences in how older adults achieve value-directed memory selectivity. We find that memory selectivity in older adults is associated with value-related changes in activation during word presentation in left hemisphere regions that are involved in semantic processing, similar to young adults. However, highly selective young adults show a relatively greater increase in semantic network activity during encoding of high-value items, whereas highly selective older adults show relatively diminished activity during encoding of low-value items. Additionally, only younger adults showed value-related increases in activity in semantic and reward processing regions during presentation of the value cue preceding each to-be-remembered word. Young adults therefore respond to cue value more proactively than do older adults, yet the magnitude of value-related differences in cue period brain activity did not predict individual differences in memory selectivity. Thus, our data also show that age-related reductions in prestimulus activity do not always lead to inefficient performance. PMID:26244278

Programmable optical processor chips: toward photonic RF filters with DSP-level flexibility and MHz-band selectivity

NASA Astrophysics Data System (ADS)

Xie, Yiwei; Geng, Zihan; Zhuang, Leimeng; Burla, Maurizio; Taddei, Caterina; Hoekman, Marcel; Leinse, Arne; Roeloffzen, Chris G. H.; Boller, Klaus-J.; Lowery, Arthur J.

2017-12-01

Integrated optical signal processors have been identified as a powerful engine for optical processing of microwave signals. They enable wideband and stable signal processing operations on miniaturized chips with ultimate control precision. As a promising application, such processors enables photonic implementations of reconfigurable radio frequency (RF) filters with wide design flexibility, large bandwidth, and high-frequency selectivity. This is a key technology for photonic-assisted RF front ends that opens a path to overcoming the bandwidth limitation of current digital electronics. Here, the recent progress of integrated optical signal processors for implementing such RF filters is reviewed. We highlight the use of a low-loss, high-index-contrast stoichiometric silicon nitride waveguide which promises to serve as a practical material platform for realizing high-performance optical signal processors and points toward photonic RF filters with digital signal processing (DSP)-level flexibility, hundreds-GHz bandwidth, MHz-band frequency selectivity, and full system integration on a chip scale.

Pretest Measures of the Study Outcome and the Elimination of Selection Bias: Evidence from Three Within Study Comparisons.

PubMed

Hallberg, Kelly; Cook, Thomas D; Steiner, Peter M; Clark, M H

2018-04-01

This paper examines how pretest measures of a study outcome reduce selection bias in observational studies in education. The theoretical rationale for privileging pretests in bias control is that they are often highly correlated with the outcome, and in many contexts, they are also highly correlated with the selection process. To examine the pretest's role in bias reduction, we use the data from two within study comparisons and an especially strong quasi-experiment, each with an educational intervention that seeks to improve achievement. In each study, the pretest measures are consistently highly correlated with post-intervention measures of themselves, but the studies vary the correlation between the pretest and the process of selection into treatment. Across the three datasets with two outcomes each, there are three cases where this correlation is low and three where it is high. A single wave of pretest always reduces bias across the six instances examined, and it eliminates bias in three of them. Adding a second pretest wave eliminates bias in two more instances. However, the pattern of bias elimination does not follow the predicted pattern-that more bias reduction ensues as a function of how highly the pretest is correlated with selection. The findings show that bias is more complexly related to the pretest's correlation with selection than we hypothesized, and we seek to explain why.

Harnessing the Big Data Paradigm for ICME: Shifting from Materials Selection to Materials Enabled Design

NASA Astrophysics Data System (ADS)

Broderick, Scott R.; Santhanam, Ganesh Ram; Rajan, Krishna

2016-08-01

As the size of databases has significantly increased, whether through high throughput computation or through informatics-based modeling, the challenge of selecting the optimal material for specific design requirements has also arisen. Given the multiple, and often conflicting, design requirements, this selection process is not as trivial as sorting the database for a given property value. We suggest that the materials selection process should minimize selector bias, as well as take data uncertainty into account. For this reason, we discuss and apply decision theory for identifying chemical additions to Ni-base alloys. We demonstrate and compare results for both a computational array of chemistries and standard commercial superalloys. We demonstrate how we can use decision theory to select the best chemical additions for enhancing both property and processing, which would not otherwise be easily identifiable. This work is one of the first examples of introducing the mathematical framework of set theory and decision analysis into the domain of the materials selection process.

Selective growth of titanium dioxide by low-temperature chemical vapor deposition.

PubMed

Reinke, Michael; Kuzminykh, Yury; Hoffmann, Patrik

2015-05-13

A key factor in engineering integrated optical devices such as electro-optic switches or waveguides is the patterning of thin films into specific geometries. In particular for functional oxides, etching processes are usually developed to a much lower extent than for silicon or silicon dioxide; therefore, selective area deposition techniques are of high interest for these materials. We report the selective area deposition of titanium dioxide using titanium isopropoxide and water in a high-vacuum chemical vapor deposition (HV-CVD) process at a substrate temperature of 225 °C. Here—contrary to conventional thermal CVD processes—only hydrolysis of the precursor on the surface drives the film growth as the thermal energy is not sufficient to thermally decompose the precursor. Local modification of the substrate surface energy by perfluoroalkylsilanization leads to a reduced surface residence time of the precursors and, consequently, to lower reaction rate and a prolonged incubation period before nucleation occurs, hence, enabling selective area growth. We discuss the dependence of the incubation time and the selectivity of the deposition process on the presence of the perfluoroalkylsilanization layer and on the precursor impinging rates—with selectivity, we refer to the difference of desired material deposition, before nucleation occurs in the undesired regions. The highest measured selectivity reached (99 ± 5) nm, a factor of 3 superior than previously reported in an atomic layer deposition process using the same chemistry. Furthermore, resolution of the obtained patterns will be discussed and illustrated.

Hadoop neural network for parallel and distributed feature selection.

PubMed

Hodge, Victoria J; O'Keefe, Simon; Austin, Jim

2016-06-01

In this paper, we introduce a theoretical basis for a Hadoop-based neural network for parallel and distributed feature selection in Big Data sets. It is underpinned by an associative memory (binary) neural network which is highly amenable to parallel and distributed processing and fits with the Hadoop paradigm. There are many feature selectors described in the literature which all have various strengths and weaknesses. We present the implementation details of five feature selection algorithms constructed using our artificial neural network framework embedded in Hadoop YARN. Hadoop allows parallel and distributed processing. Each feature selector can be divided into subtasks and the subtasks can then be processed in parallel. Multiple feature selectors can also be processed simultaneously (in parallel) allowing multiple feature selectors to be compared. We identify commonalities among the five features selectors. All can be processed in the framework using a single representation and the overall processing can also be greatly reduced by only processing the common aspects of the feature selectors once and propagating these aspects across all five feature selectors as necessary. This allows the best feature selector and the actual features to select to be identified for large and high dimensional data sets through exploiting the efficiency and flexibility of embedding the binary associative-memory neural network in Hadoop. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Process for restoring membrane permeation properties

DOEpatents

Pinnau, Ingo; Toy, Lora G.; Casillas, Carlos G.

1997-05-20

A process for restoring the selectivity of high-flee-volume, glassy polymer membranes for condensable components over less-condensable components or non-condensable components of a gas mixture. The process involves exposing the membrane to suitable sorbent vapor, such as propane or butane, thereby reopening the microvoids that make up the free volume. The selectivity of an aged membrane may be restored to 70-100% of its original value. The selectivity of a membrane which is known to age over time can also be maintained by keeping the membrane in a vapor environment when it is not in use.

Process for restoring membrane permeation properties

DOEpatents

Pinnau, I.; Toy, L.G.; Casillas, C.G.

1997-05-20

A process is described for restoring the selectivity of high-free-volume, glassy polymer membranes for condensable components over less-condensable components or non-condensable components of a gas mixture. The process involves exposing the membrane to suitable sorbent vapor, such as propane or butane, thereby reopening the microvoids that make up the free volume. The selectivity of an aged membrane may be restored to 70--100% of its original value. The selectivity of a membrane which is known to age over time can also be maintained by keeping the membrane in a vapor environment when it is not in use. 8 figs.

Competitive Parallel Processing For Compression Of Data

NASA Technical Reports Server (NTRS)

Diner, Daniel B.; Fender, Antony R. H.

1990-01-01

Momentarily-best compression algorithm selected. Proposed competitive-parallel-processing system compresses data for transmission in channel of limited band-width. Likely application for compression lies in high-resolution, stereoscopic color-television broadcasting. Data from information-rich source like color-television camera compressed by several processors, each operating with different algorithm. Referee processor selects momentarily-best compressed output.

Low-sensitivity, frequency-selective amplifier circuits for hybrid and bipolar fabrication.

NASA Technical Reports Server (NTRS)

Pi, C.; Dunn, W. R., Jr.

1972-01-01

A network is described which is suitable for realizing a low-sensitivity high-Q second-order frequency-selective amplifier for high-frequency operation. Circuits are obtained from this network which are well suited for realizing monolithic integrated circuits and which do not require any process steps more critical than those used for conventional monolithic operational and video amplifiers. A single chip version using compatible thin-film techniques for the frequency determination elements is then feasible. Center frequency and bandwidth can be set independently by trimming two resistors. The frequency selective circuits have a low sensitivity to the process variables, and the sensitivity of the center frequency and bandwidth to changes in temperature is very low.

A Primer on High-Throughput Computing for Genomic Selection

PubMed Central

Wu, Xiao-Lin; Beissinger, Timothy M.; Bauck, Stewart; Woodward, Brent; Rosa, Guilherme J. M.; Weigel, Kent A.; Gatti, Natalia de Leon; Gianola, Daniel

2011-01-01

High-throughput computing (HTC) uses computer clusters to solve advanced computational problems, with the goal of accomplishing high-throughput over relatively long periods of time. In genomic selection, for example, a set of markers covering the entire genome is used to train a model based on known data, and the resulting model is used to predict the genetic merit of selection candidates. Sophisticated models are very computationally demanding and, with several traits to be evaluated sequentially, computing time is long, and output is low. In this paper, we present scenarios and basic principles of how HTC can be used in genomic selection, implemented using various techniques from simple batch processing to pipelining in distributed computer clusters. Various scripting languages, such as shell scripting, Perl, and R, are also very useful to devise pipelines. By pipelining, we can reduce total computing time and consequently increase throughput. In comparison to the traditional data processing pipeline residing on the central processors, performing general-purpose computation on a graphics processing unit provide a new-generation approach to massive parallel computing in genomic selection. While the concept of HTC may still be new to many researchers in animal breeding, plant breeding, and genetics, HTC infrastructures have already been built in many institutions, such as the University of Wisconsin–Madison, which can be leveraged for genomic selection, in terms of central processing unit capacity, network connectivity, storage availability, and middleware connectivity. Exploring existing HTC infrastructures as well as general-purpose computing environments will further expand our capability to meet increasing computing demands posed by unprecedented genomic data that we have today. We anticipate that HTC will impact genomic selection via better statistical models, faster solutions, and more competitive products (e.g., from design of marker panels to realized genetic gain). Eventually, HTC may change our view of data analysis as well as decision-making in the post-genomic era of selection programs in animals and plants, or in the study of complex diseases in humans. PMID:22303303

Plastic catalytic pyrolysis to fuels as tertiary polymer recycling method: effect of process conditions.

PubMed

Gulab, Hussain; Jan, Muhammad Rasul; Shah, Jasmin; Manos, George

2010-01-01

This paper presents results regarding the effect of various process conditions on the performance of a zeolite catalyst in pyrolysis of high density polyethylene. The results show that polymer catalytic degradation can be operated at relatively low catalyst content reducing the cost of a potential industrial process. As the polymer to catalyst mass ratio increases, the system becomes less active, but high temperatures compensate for this activity loss resulting in high conversion values at usual batch times and even higher yields of liquid products due to less overcracking. The results also show that high flow rate of carrier gas causes evaporation of liquid products falsifying results, as it was obvious from liquid yield results at different reaction times as well as the corresponding boiling point distributions. Furthermore, results are presented regarding temperature effects on liquid selectivity. Similar values resulted from different final reactor temperatures, which are attributed to the batch operation of the experimental equipment. Since polymer and catalyst both undergo the same temperature profile, which is the same up to a specific time independent of the final temperature. Obviously, this common temperature step determines the selectivity to specific products. However, selectivity to specific products is affected by the temperature, as shown in the corresponding boiling point distributions, with higher temperatures showing an increased selectivity to middle boiling point components (C(8)-C(9)) and lower temperatures increased selectivity to heavy components (C(14)-C(18)).

Automated Array Assembly, Phase 2. Low-cost Solar Array Project, Task 4

NASA Technical Reports Server (NTRS)

Lopez, M.

1978-01-01

Work was done to verify the technological readiness of a select process sequence with respect to satisfying the Low Cost Solar Array Project objectives of meeting the designated goals of $.50 per peak watt in 1986 (1975 dollars). The sequence examined consisted of: (1) 3 inches diameter as-sawn Czochralski grown 1:0:0 silicon, (2) texture etching, (3) ion implanting, (4) laser annealing, (5) screen printing of ohmic contacts and (6) sprayed anti-reflective coatings. High volume production projections were made on the selected process sequence. Automated processing and movement of hardware at high rates were conceptualized to satisfy the PROJECT's 500 MW/yr capability. A production plan was formulated with flow diagrams integrating the various processes in the cell fabrication sequence.

Moving into and out of High-Performance Sport: The Cultural Learning of an Artistic Gymnast

ERIC Educational Resources Information Center

Barker-Ruchti, Natalie; Schubring, Astrid

2016-01-01

Background: High-performance sport has been described as a formative environment through which athletes learn sporting skills but also develop athletic selves. Within this process, career movements related to selection for and de-selection from representative teams constitute critical moments. Further, retirement from sport can be problematic as…

Advanced High Temperature Polymer Matrix Composites for Gas Turbine Engines Program Expansion

NASA Technical Reports Server (NTRS)

Hanley, David; Carella, John

1999-01-01

This document, submitted by AlliedSignal Engines (AE), a division of AlliedSignal Aerospace Company, presents the program final report for the Advanced High Temperature Polymer Matrix Composites for Gas Turbine Engines Program Expansion in compliance with data requirements in the statement of work, Contract No. NAS3-97003. This document includes: 1 -Technical Summary: a) Component Design, b) Manufacturing Process Selection, c) Vendor Selection, and d) Testing Validation: 2-Program Conclusion and Perspective. Also, see the Appendix at the back of this report. This report covers the program accomplishments from December 1, 1996, to August 24, 1998. The Advanced High Temperature PMC's for Gas Turbine Engines Program Expansion was a one year long, five task technical effort aimed at designing, fabricating and testing a turbine engine component using NASA's high temperature resin system AMB-21. The fiber material chosen was graphite T650-35, 3K, 8HS with UC-309 sizing. The first four tasks included component design and manufacturing, process selection, vendor selection, component fabrication and validation testing. The final task involved monthly financial and technical reports.

West Valley demonstration project: Alternative processes for solidifying the high-level wastes

NASA Astrophysics Data System (ADS)

Holton, L. K.; Larson, D. E.; Partain, W. L.; Treat, R. L.

1981-10-01

Two pretreatment approaches and several waste form processes for radioactive wastes were selected for evaluation. The two waste treatment approaches were the salt/sludge separation process and the combined waste process. Both terminal and interim waste form processes were studied.

A Developmental Assessment of Motor Performance in High M-Processing and Low M-Processing Children.

ERIC Educational Resources Information Center

Bender, Peter R.

This study was undertaken to determine whether neo-Piagetian theory might provide a functional interpretation of children's motor development, particularly linear positioning. In addition, intra-age and inter-age comparisons for both high- and low-mental-processing children were made. Pascual-Leone's Figural Intersection Test was used to select 15…

Beyond perceptual load and dilution: a review of the role of working memory in selective attention

PubMed Central

de Fockert, Jan W.

2013-01-01

The perceptual load and dilution models differ fundamentally in terms of the proposed mechanism underlying variation in distractibility during different perceptual conditions. However, both models predict that distracting information can be processed beyond perceptual processing under certain conditions, a prediction that is well-supported by the literature. Load theory proposes that in such cases, where perceptual task aspects do not allow for sufficient attentional selectivity, the maintenance of task-relevant processing depends on cognitive control mechanisms, including working memory. The key prediction is that working memory plays a role in keeping clear processing priorities in the face of potential distraction, and the evidence reviewed and evaluated in a meta-analysis here supports this claim, by showing that the processing of distracting information tends to be enhanced when load on a concurrent task of working memory is high. Low working memory capacity is similarly associated with greater distractor processing in selective attention, again suggesting that the unavailability of working memory during selective attention leads to an increase in distractibility. Together, these findings suggest that selective attention against distractors that are processed beyond perception depends on the availability of working memory. Possible mechanisms for the effects of working memory on selective attention are discussed. PMID:23734139

Beyond perceptual load and dilution: a review of the role of working memory in selective attention.

PubMed

de Fockert, Jan W

2013-01-01

The perceptual load and dilution models differ fundamentally in terms of the proposed mechanism underlying variation in distractibility during different perceptual conditions. However, both models predict that distracting information can be processed beyond perceptual processing under certain conditions, a prediction that is well-supported by the literature. Load theory proposes that in such cases, where perceptual task aspects do not allow for sufficient attentional selectivity, the maintenance of task-relevant processing depends on cognitive control mechanisms, including working memory. The key prediction is that working memory plays a role in keeping clear processing priorities in the face of potential distraction, and the evidence reviewed and evaluated in a meta-analysis here supports this claim, by showing that the processing of distracting information tends to be enhanced when load on a concurrent task of working memory is high. Low working memory capacity is similarly associated with greater distractor processing in selective attention, again suggesting that the unavailability of working memory during selective attention leads to an increase in distractibility. Together, these findings suggest that selective attention against distractors that are processed beyond perception depends on the availability of working memory. Possible mechanisms for the effects of working memory on selective attention are discussed.

Examining Mechanical Strength Characteristics of Selective Inhibition Sintered HDPE Specimens Using RSM and Desirability Approach

NASA Astrophysics Data System (ADS)

Rajamani, D.; Esakki, Balasubramanian

2017-09-01

Selective inhibition sintering (SIS) is a powder based additive manufacturing (AM) technique to produce functional parts with an inexpensive system compared with other AM processes. Mechanical properties of SIS fabricated parts are of high dependence on various process parameters importantly layer thickness, heat energy, heater feedrate, and printer feedrate. In this paper, examining the influence of these process parameters on evaluating mechanical properties such as tensile and flexural strength using Response Surface Methodology (RSM) is carried out. The test specimens are fabricated using high density polyethylene (HDPE) and mathematical models are developed to correlate the control factors to the respective experimental design response. Further, optimal SIS process parameters are determined using desirability approach to enhance the mechanical properties of HDPE specimens. Optimization studies reveal that, combination of high heat energy, low layer thickness, medium heater feedrate and printer feedrate yielded superior mechanical strength characteristics.

Gear materials for high-production light-deputy service

NASA Technical Reports Server (NTRS)

Townsend, D. P.

1973-01-01

The selection of a material for high volume, low cost gears requires careful consideration of all the requirements and the processes used to manufacture the gears. The wrong choice in material selection could very well mean the difference between success and failure. A summary of the cost that might be expected for different materials and processes is presented; it can be seen that the cost can span nearly three order of magnitudes from the molded plastic gear to the machined gear with stamped and powder metal gears falling in between these extremes.

Hypericin-mediated selective photomodification of connective tissues

NASA Astrophysics Data System (ADS)

Hovhannisyan, V.; Hovhannisyan, A.; Ghukasyan, V.; Guo, H. W.; Lin, Hung-Ming; Chen, S. J.; Chen, Yang-Fang; Dong, Chen-Yuan

2017-02-01

Hypericin (Hyp) has received attention due to its high phototoxicity against viruses and anti-tumor photoactivity. Using two-photon imaging, we demonstrated that Hyp induced photosensitized modification of collagen fibers in native tissues. Dynamics of photo-processes was monitored by time-lapse multiphoton imaging. We showed that Hyp-mediated processes in collagen tissues may be used for the selective modification of collagen fibers.

An Alternative to Adaptation by Sexual Selection: Habitat Choice.

PubMed

Porter, Cody K; Akcali, Christopher K

2018-06-09

Adaptation in mating signals and preferences has generally been explained by sexual selection. We propose that adaptation in such mating traits might also arise via a non-mutually exclusive process wherein individuals preferentially disperse to habitats where they experience high mating performance. Here we explore the evolutionary implications of this process. Copyright © 2018 Elsevier Ltd. All rights reserved.

Rapid high-throughput cloning and stable expression of antibodies in HEK293 cells.

PubMed

Spidel, Jared L; Vaessen, Benjamin; Chan, Yin Yin; Grasso, Luigi; Kline, J Bradford

2016-12-01

Single-cell based amplification of immunoglobulin variable regions is a rapid and powerful technique for cloning antigen-specific monoclonal antibodies (mAbs) for purposes ranging from general laboratory reagents to therapeutic drugs. From the initial screening process involving small quantities of hundreds or thousands of mAbs through in vitro characterization and subsequent in vivo experiments requiring large quantities of only a few, having a robust system for generating mAbs from cloning through stable cell line generation is essential. A protocol was developed to decrease the time, cost, and effort required by traditional cloning and expression methods by eliminating bottlenecks in these processes. Removing the clonal selection steps from the cloning process using a highly efficient ligation-independent protocol and from the stable cell line process by utilizing bicistronic plasmids to generate stable semi-clonal cell pools facilitated an increased throughput of the entire process from plasmid assembly through transient transfections and selection of stable semi-clonal cell pools. Furthermore, the time required by a single individual to clone, express, and select stable cell pools in a high-throughput format was reduced from 4 to 6months to only 4 to 6weeks. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Experimental evolution in Drosophila melanogaster: interaction of temperature and food quality selection regimes.

PubMed

Bochdanovits, Zoltán; de Jong, Gerdien

2003-08-01

In Drosophila, both the phenotypic and evolutionary effect of temperature on adult size involves alterations to larval resource processing and affects other life-history traits, that is, development time but most notably, larval survival. Therefore, thermal evolution of adult body size might not be independent of simultaneous adaptation of larval traits to resource availability. Using experimental evolution lines adapted to high and low temperatures at different levels of food, we show that selection pressures interact in shaping larval resource processing. Evolution on poor food invariably leads to lower resource acquisition suggesting a cost to feeding behavior. However, following low temperature selection, lower resource acquisition led to a higher adult body size, probably by more efficient allocation to growth. In contrast, following high temperature selection, low resource acquisition benefited larval survival, possibly by reducing feeding-associated costs. We show that evolved differences to larval resource processing provide a possible proximate mechanism to variation in a suite of correlated life-history traits during adaptation to different climates. The implication for natural populations is that in nature, thermal evolution drives populations to opposite ends of an adult size versus larval survival trade-off by altering resource processing, if resource availability is limited.

Individual Alpha Peak Frequency Predicts 10 Hz Flicker Effects on Selective Attention.

PubMed

Gulbinaite, Rasa; van Viegen, Tara; Wieling, Martijn; Cohen, Michael X; VanRullen, Rufin

2017-10-18

Rhythmic visual stimulation ("flicker") is primarily used to "tag" processing of low-level visual and high-level cognitive phenomena. However, preliminary evidence suggests that flicker may also entrain endogenous brain oscillations, thereby modulating cognitive processes supported by those brain rhythms. Here we tested the interaction between 10 Hz flicker and endogenous alpha-band (∼10 Hz) oscillations during a selective visuospatial attention task. We recorded EEG from human participants (both genders) while they performed a modified Eriksen flanker task in which distractors and targets flickered within (10 Hz) or outside (7.5 or 15 Hz) the alpha band. By using a combination of EEG source separation, time-frequency, and single-trial linear mixed-effects modeling, we demonstrate that 10 Hz flicker interfered with stimulus processing more on incongruent than congruent trials (high vs low selective attention demands). Crucially, the effect of 10 Hz flicker on task performance was predicted by the distance between 10 Hz and individual alpha peak frequency (estimated during the task). Finally, the flicker effect on task performance was more strongly predicted by EEG flicker responses during stimulus processing than during preparation for the upcoming stimulus, suggesting that 10 Hz flicker interfered more with reactive than proactive selective attention. These findings are consistent with our hypothesis that visual flicker entrained endogenous alpha-band networks, which in turn impaired task performance. Our findings also provide novel evidence for frequency-dependent exogenous modulation of cognition that is determined by the correspondence between the exogenous flicker frequency and the endogenous brain rhythms. SIGNIFICANCE STATEMENT Here we provide novel evidence that the interaction between exogenous rhythmic visual stimulation and endogenous brain rhythms can have frequency-specific behavioral effects. We show that alpha-band (10 Hz) flicker impairs stimulus processing in a selective attention task when the stimulus flicker rate matches individual alpha peak frequency. The effect of sensory flicker on task performance was stronger when selective attention demands were high, and was stronger during stimulus processing and response selection compared with the prestimulus anticipatory period. These findings provide novel evidence that frequency-specific sensory flicker affects online attentional processing, and also demonstrate that the correspondence between exogenous and endogenous rhythms is an overlooked prerequisite when testing for frequency-specific cognitive effects of flicker. Copyright © 2017 the authors 0270-6474/17/3710173-12$15.00/0.

Additive manufacturing of metals: a brief review of the characteristic microstructures and properties of steels, Ti-6Al-4V and high-entropy alloys.

PubMed

Gorsse, Stéphane; Hutchinson, Christopher; Gouné, Mohamed; Banerjee, Rajarshi

2017-01-01

We present a brief review of the microstructures and mechanical properties of selected metallic alloys processed by additive manufacturing (AM). Three different alloys, covering a large range of technology readiness levels, are selected to illustrate particular microstructural features developed by AM and clarify the engineering paradigm relating process-microstructure-property. With Ti-6Al-4V the emphasis is placed on the formation of metallurgical defects and microstructures induced by AM and their role on mechanical properties. The effects of the large in-built dislocation density, surface roughness and build atmosphere on mechanical and damage properties are discussed using steels. The impact of rapid solidification inherent to AM on phase selection is highlighted for high-entropy alloys. Using property maps, published mechanical properties of additive manufactured alloys are graphically summarized and compared to conventionally processed counterparts.

Additive manufacturing of metals: a brief review of the characteristic microstructures and properties of steels, Ti-6Al-4V and high-entropy alloys

NASA Astrophysics Data System (ADS)

Gorsse, Stéphane; Hutchinson, Christopher; Gouné, Mohamed; Banerjee, Rajarshi

2017-12-01

We present a brief review of the microstructures and mechanical properties of selected metallic alloys processed by additive manufacturing (AM). Three different alloys, covering a large range of technology readiness levels, are selected to illustrate particular microstructural features developed by AM and clarify the engineering paradigm relating process-microstructure-property. With Ti-6Al-4V the emphasis is placed on the formation of metallurgical defects and microstructures induced by AM and their role on mechanical properties. The effects of the large in-built dislocation density, surface roughness and build atmosphere on mechanical and damage properties are discussed using steels. The impact of rapid solidification inherent to AM on phase selection is highlighted for high-entropy alloys. Using property maps, published mechanical properties of additive manufactured alloys are graphically summarized and compared to conventionally processed counterparts.

Selective, ultrathin membrane skins prepared by deposition of novel polymer films on porous alumina supports

NASA Astrophysics Data System (ADS)

Balachandra, Anagi Manjula

Membrane-based separations are attractive in industrial processes because of their low energy costs and simple operation. However, low permeabilities often make membrane processes uneconomical. Since flux is inversely proportional to membrane thickness, composite membranes consisting of ultrathin, selective skins on highly permeable supports are required to simultaneously achieve high throughput and high selectivity. However, the synthesis of defect-free skins with thicknesses less than 50 nm is difficult, and thus flux is often limited. Layer-by-layer deposition of oppositely charged polyelectrolytes on porous supports is an attractive method to synthesize ultrathin ion-separation membranes with high flux and high selectivity. The ion-transport selectivity of multilayer polyelectrolyte membranes (MPMs) is primarily due to Donnan exclusion; therefore increase in fixed charge density should yield high selectivity. However, control over charge density in MPMs is difficult because charges on polycations are electrostatically compensated by charges on polyanions, and the net charge in the bulk of these films is small. To overcome this problem, we introduced a templating method to create ion-exchange sites in the bulk of the membrane. This strategy involves alternating deposition of a Cu2+-poly(acrylic acid) complex and poly(allylamine hydrochloride) on a porous alumina support followed by removal of Cu2+ and deprotonation to yield free -COO- ion-exchange sites. Diffusion dialysis studies showed that the Cl-/SO42-. Selectivity of Cu2+-templated membranes is 4-fold higher than that of membranes prepared in the absence of Cu2+. Post-deposition cross-linking of these membranes by heat-induced amide bond formation further increased Cl-/SO42- selectivity to values as high as 600. Room-temperature, surface-initiated atom transfer radical polymerization (ATRP) provides another convenient method for formation of ultrathin polymer skins. This process involves attachment of polymerization initiators to a porous alumina support and subsequent polymerization from these initiators. Because ATRP is a controlled polymerization technique, it yields well-defined polymer films with low polydispersity indices (narrow molecular weight distributions). Additionally, this method is attractive because film thickness can be easily controlled by adjusting polymerization time. Gas-permeability data showed that grafted poly(ethylene glycol dimethacrylate) membranes have a CO 2/CH4 selectivity of 20, whereas poly(2-hydroxyethyl methacrylate) (PHEMA) films grown from a surface have negligible selectivity. However, derivatization of PHEMA with pentadecafluorooctanoyl chloride increases the solubility of CO2 in the membrane and results in a CO2/CH4 selectivity of 9. Although composite PHEMA membranes have no significant gas-transport selectivity, diffusion dialysis studies with PHEMA membranes showed moderate ion-transport selectivities. Cross-linking of PHEMA membranes by reaction with succinyl chloride greatly enhanced anion-transport selectivities while maintaining reasonable flux. The selectivities of these systems demonstrate that alternating polyelectrolyte deposition and surface-initiated ATRP are indeed capable of forming ultrathin, defect-free membrane skins that can potentially be modified for specific separations.

Mask-less patterning of organic light emitting diodes using electrospray and selective biasing on pixel electrodes

NASA Astrophysics Data System (ADS)

Lee, Sangyeob; Koo, Hyun; Cho, Sunghwan

2015-04-01

Wet process of soluble organic light emitting diode (OLED) materials has attracted much attention due to its potential as a large-area manufacturing process with high productivity. Electrospray (ES) deposition is one of candidates of organic thin film formation process for OLED. However, to fabricate red, green, and blue emitters for color display, a fine metal mask is required during spraying emitter materials. We demonstrate a mask-less color pixel patterning process using ES of soluble OLED materials and selective biasing on pixel electrodes and a spray nozzle. We show red and green line patterns of OLED materials. It was found that selective patterning can be allowed by coulomb repulsion between nozzle and pixel. Furthermore, we fabricated blue fluorescent OLED devices by vacuum evaporation and ES processes. The device performance of ES processed OLED showed nearly identical current-voltage characteristics and slightly lower current efficiency compared to vacuum processed OLED.

What Every Public School Physical Educator Should Know about the Hiring Process

ERIC Educational Resources Information Center

Stier, William F., Jr.; Schneider, Robert C.

2007-01-01

A national survey of high school principals was conducted to determine whether they agreed or disagreed with selected practices and procedures used to hire high school physical education teachers. A survey instrument, developed with the help of experts in the field and consisting of 29 items, was sent to 400 randomly selected principals. Useable…

Enhancement of neutral lipid productivity in the microalga Isochrysis affinis Galbana (T-Iso) by a mutation-selection procedure.

PubMed

Bougaran, Gaël; Rouxel, Catherine; Dubois, Nolwenn; Kaas, Raymond; Grouas, Sophie; Lukomska, Ewa; Le Coz, Jean-René; Cadoret, Jean-Paul

2012-11-01

Microalgae offer a high potential for energetic lipid storage as well as high growth rates. They are therefore considered promising candidates for biofuel production, with the selection of high lipid-producing strains a major objective in projects on the development of this technology. We developed a mutation-selection method aimed at increasing microalgae neutral lipid productivity. A two step method, based on UVc irradiation followed by flow cytometry selection, was applied to a set of strains that had an initial high lipid content and improvement was assessed by means of Nile-red fluorescence measurements. The method was first tested on Isochrysis affinis galbana (T-Iso). Following a first round of mutation-selection, the total fatty acid content had not increased significantly, being 262 ± 21 mgTFA (gC)-1 for the wild type (WT) and 269 ± 49 mgTFA (gC)-1 for the selected population (S1M1). Conversely, fatty acid distribution among the lipid classes was affected by the process, resulting in a 20% increase for the fatty acids in the neutral lipids and a 40% decrease in the phospholipids. After a second mutation-selection step (S2M2), the total fatty acid content reached 409 ± 64 mgTFA (gC)-1 with a fatty acid distribution similar to the S1M1 population. Growth rate remained unaffected by the process, resulting in a 80% increase for neutral lipid productivity. Copyright © 2012 Wiley Periodicals, Inc.

Pulp extrusion at ultra-high consistencies : selection of water soluble polymers for process optimization

Treesearch

C. Tim Scott

2002-01-01

Pulp extrusion at ultra-high consistencies (20% to 40% solids) is a new process developed at USDA Forest Service, Forest Products Laboratory (FPL) to convert recovered papers, wastepaper, and papermill residuals into solid sheets or profiles for compression molding. This process requires adding a water-soluble polymer (WSP) to alter the rheological properties of the...

A highly manufacturable 0.2 {mu}m AlGaAs/InGaAs PHEMT fabricated using the single-layer integrated-metal FET (SLIMFET) process

DOE Office of Scientific and Technical Information (OSTI.GOV)

Havasy, C.K.; Quach, T.K.; Bozada, C.A.

1995-12-31

This work is the development of a single-layer integrated-metal field effect transistor (SLIMFET) process for a high performance 0.2 {mu}m AlGaAs/InGaAs pseudomorphic high electron mobility transistor (PHEMT). This process is compatible with MMIC fabrication and minimizes process variations, cycle time, and cost. This process uses non-alloyed ohmic contacts, a selective gate-recess etching process, and a single gate/source/drain metal deposition step to form both Schottky and ohmic contacts at the same time.

Organocatalytic asymmetric anti-selective Michael reactions of aldehydes and the sequential reduction/lactonization/Pauson-Khand reaction for the enantioselective synthesis of highly functionalized hydropentalenes.

PubMed

Hong, Bor-Cherng; Dange, Nitin S; Yen, Po-Jen; Lee, Gene-Hsiang; Liao, Ju-Hsiou

2012-10-19

A new method has been developed for the enantioselective synthesis of highly functionalized hydropentalenes bearing up to four stereogenic centers with high stereoselectivity (up to 99% ee). This process combines an enantioselective organocatalytic anti-selective Michael addition with a highly efficient one-pot reduction/lactonization/Pauson-Khand reaction sequence. The structures and absolute configurations of the products were confirmed by X-ray analysis.

Comparison of Whole-Cell SELEX Methods for the Identification of Staphylococcus Aureus-Specific DNA Aptamers

PubMed Central

Moon, Jihea; Kim, Giyoung; Park, Saet Byeol; Lim, Jongguk; Mo, Changyeun

2015-01-01

Whole-cell Systemic Evolution of Ligands by Exponential enrichment (SELEX) is the process by which aptamers specific to target cells are developed. Aptamers selected by whole-cell SELEX have high affinity and specificity for bacterial surface molecules and live bacterial targets. To identify DNA aptamers specific to Staphylococcus aureus, we applied our rapid whole-cell SELEX method to a single-stranded ssDNA library. To improve the specificity and selectivity of the aptamers, we designed, selected, and developed two categories of aptamers that were selected by two kinds of whole-cell SELEX, by mixing and combining FACS analysis and a counter-SELEX process. Using this approach, we have developed a biosensor system that employs a high affinity aptamer for detection of target bacteria. FAM-labeled aptamer sequences with high binding to S. aureus, as determined by fluorescence spectroscopic analysis, were identified, and aptamer A14, selected by the basic whole-cell SELEX using a once-off FACS analysis, and which had a high binding affinity and specificity, was chosen. The binding assay was evaluated using FACS analysis. Our study demonstrated the development of a set of whole-cell SELEX derived aptamers specific to S. aureus; this approach can be used in the identification of other bacteria. PMID:25884791

Comparison of whole-cell SELEX methods for the identification of Staphylococcus aureus-specific DNA aptamers.

PubMed

Moon, Jihea; Kim, Giyoung; Park, Saet Byeol; Lim, Jongguk; Mo, Changyeun

2015-04-15

Whole-cell Systemic Evolution of Ligands by Exponential enrichment (SELEX) is the process by which aptamers specific to target cells are developed. Aptamers selected by whole-cell SELEX have high affinity and specificity for bacterial surface molecules and live bacterial targets. To identify DNA aptamers specific to Staphylococcus aureus, we applied our rapid whole-cell SELEX method to a single-stranded ssDNA library. To improve the specificity and selectivity of the aptamers, we designed, selected, and developed two categories of aptamers that were selected by two kinds of whole-cell SELEX, by mixing and combining FACS analysis and a counter-SELEX process. Using this approach, we have developed a biosensor system that employs a high affinity aptamer for detection of target bacteria. FAM-labeled aptamer sequences with high binding to S. aureus, as determined by fluorescence spectroscopic analysis, were identified, and aptamer A14, selected by the basic whole-cell SELEX using a once-off FACS analysis, and which had a high binding affinity and specificity, was chosen. The binding assay was evaluated using FACS analysis. Our study demonstrated the development of a set of whole-cell SELEX derived aptamers specific to S. aureus; this approach can be used in the identification of other bacteria.

Behind the scenes: how visual memory load biases selective attention during processing of visual streams.

PubMed

Klaver, Peter; Talsma, Durk

2013-11-01

We recorded ERPs to investigate whether the visual memory load can bias visual selective attention. Participants memorized one or four letters and then responded to memory-matching letters presented in a relevant color while ignoring distractor letters or letters in an irrelevant color. Stimuli in the relevant color elicited larger frontal selection positivities (FSP) and occipital selection negativities (OSN) compared to irrelevant color stimuli. Only distractors elicited a larger FSP in the high than in the low memory load task. Memory load prolonged the OSN for all letters. Response mapping complexity was also modulated but did not affect the FSP and OSN. Together, the FSP data suggest that high memory load increased distractability. The OSN data suggest that memory load sustained attention to letters in a relevant color until working memory processing was completed, independently of whether the letters were in working memory or not. Copyright © 2013 Society for Psychophysiological Research.

Attention to Color Sharpens Neural Population Tuning via Feedback Processing in the Human Visual Cortex Hierarchy.

PubMed

Bartsch, Mandy V; Loewe, Kristian; Merkel, Christian; Heinze, Hans-Jochen; Schoenfeld, Mircea A; Tsotsos, John K; Hopf, Jens-Max

2017-10-25

Attention can facilitate the selection of elementary object features such as color, orientation, or motion. This is referred to as feature-based attention and it is commonly attributed to a modulation of the gain and tuning of feature-selective units in visual cortex. Although gain mechanisms are well characterized, little is known about the cortical processes underlying the sharpening of feature selectivity. Here, we show with high-resolution magnetoencephalography in human observers (men and women) that sharpened selectivity for a particular color arises from feedback processing in the human visual cortex hierarchy. To assess color selectivity, we analyze the response to a color probe that varies in color distance from an attended color target. We find that attention causes an initial gain enhancement in anterior ventral extrastriate cortex that is coarsely selective for the target color and transitions within ∼100 ms into a sharper tuned profile in more posterior ventral occipital cortex. We conclude that attention sharpens selectivity over time by attenuating the response at lower levels of the cortical hierarchy to color values neighboring the target in color space. These observations support computational models proposing that attention tunes feature selectivity in visual cortex through backward-propagating attenuation of units less tuned to the target. SIGNIFICANCE STATEMENT Whether searching for your car, a particular item of clothing, or just obeying traffic lights, in everyday life, we must select items based on color. But how does attention allow us to select a specific color? Here, we use high spatiotemporal resolution neuromagnetic recordings to examine how color selectivity emerges in the human brain. We find that color selectivity evolves as a coarse to fine process from higher to lower levels within the visual cortex hierarchy. Our observations support computational models proposing that feature selectivity increases over time by attenuating the responses of less-selective cells in lower-level brain areas. These data emphasize that color perception involves multiple areas across a hierarchy of regions, interacting with each other in a complex, recursive manner. Copyright © 2017 the authors 0270-6474/17/3710346-12$15.00/0.

Automated frame selection process for high-resolution microendoscopy

NASA Astrophysics Data System (ADS)

Ishijima, Ayumu; Schwarz, Richard A.; Shin, Dongsuk; Mondrik, Sharon; Vigneswaran, Nadarajah; Gillenwater, Ann M.; Anandasabapathy, Sharmila; Richards-Kortum, Rebecca

2015-04-01

We developed an automated frame selection algorithm for high-resolution microendoscopy video sequences. The algorithm rapidly selects a representative frame with minimal motion artifact from a short video sequence, enabling fully automated image analysis at the point-of-care. The algorithm was evaluated by quantitative comparison of diagnostically relevant image features and diagnostic classification results obtained using automated frame selection versus manual frame selection. A data set consisting of video sequences collected in vivo from 100 oral sites and 167 esophageal sites was used in the analysis. The area under the receiver operating characteristic curve was 0.78 (automated selection) versus 0.82 (manual selection) for oral sites, and 0.93 (automated selection) versus 0.92 (manual selection) for esophageal sites. The implementation of fully automated high-resolution microendoscopy at the point-of-care has the potential to reduce the number of biopsies needed for accurate diagnosis of precancer and cancer in low-resource settings where there may be limited infrastructure and personnel for standard histologic analysis.

Selecting Resident Assistants: The Relationship between Candidate Assessment and Job Performance

ERIC Educational Resources Information Center

Berg, Stephen A.; Stoner, James C.

2016-01-01

Selecting resident assistants is integral to the success of housing operations on college and university campuses. Recruiting high-performing student staff is a priority in achieving departmental goals. Despite the importance of this process and the amount of time and resources expended during selection, there is scarce research investigating the…

A Teacher's Guide to Selective Service Registration.

ERIC Educational Resources Information Center

Selective Service System, Washington, DC.

This guide is designed to assist high school teachers in their preparation of lessons covering the Selective Service System. The guide is organized into seven chapters. Chapter 1 describes Selective Service as it exists today, explains the registration process and its role in the national defense system, details who must register, and emphasizes…

High purity silica reflective heat shield development

NASA Technical Reports Server (NTRS)

Nachtscheim, P. R.; Blome, J. C.

1976-01-01

A hyperpure vitreous silica material is being developed for use as a reflective and ablative heat shield for planetary entry. Various purity grades and forms of raw materials were evaluated along with various processing methods. Slip casting of high purity grain was selected as the best processing method, resulting in a highly reflective material in the wavelength bands of interest (the visible and ultraviolet regions). The selected material was characterized with respect to optical, mechanical and physical properties using a limited number of specimens. The process has been scaled up to produce a one-half scale heat shield (18 in. dia.) (45.72 cm) for a Jupiter entry vehicle. This work is now being extended to improve the structural safety factor of the heat shield by making hyperpure silica material tougher through the addition of silica fibers.

Cryogenic Etching of High Aspect Ratio 400 nm Pitch Silicon Gratings.

PubMed

Miao, Houxun; Chen, Lei; Mirzaeimoghri, Mona; Kasica, Richard; Wen, Han

2016-10-01

The cryogenic process and Bosch process are two widely used processes for reactive ion etching of high aspect ratio silicon structures. This paper focuses on the cryogenic deep etching of 400 nm pitch silicon gratings with various etching mask materials including polymer, Cr, SiO 2 and Cr-on-polymer. The undercut is found to be the key factor limiting the achievable aspect ratio for the direct hard masks of Cr and SiO 2 , while the etch selectivity responds to the limitation of the polymer mask. The Cr-on-polymer mask provides the same high selectivity as Cr and reduces the excessive undercut introduced by direct hard masks. By optimizing the etching parameters, we etched a 400 nm pitch grating to ≈ 10.6 μ m depth, corresponding to an aspect ratio of ≈ 53.

Chiral recognition and selection during the self-assembly process of protein-mimic macroanions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yin, Panchao; Zhang, Zhi-Ming; Lv, Hongjin

The research on chiral recognition and chiral selection is not only fundamental in resolving the puzzle of homochirality, but also instructive in chiral separation and stereoselective catalysis. Here we report the chiral recognition and chiral selection during the self-assembly process of two enantiomeric wheel-shaped macroanions, [Fe28(μ3-O)8(Tart)16(HCOO)24]20- (Tart=D- or L-tartaric acid tetra-anion). The enantiomers are observed to remain self-sorted and self-assemble into their individual assemblies in their racemic mixture solution. The addition of chiral co-anions can selectively suppress the self-assembly process of the enantiomeric macroanions, which is further used to separate the two enantiomers from their mixtures on the basis ofmore » the size difference between the monomers and the assemblies. We believe that delicate long-range electrostatic interactions could be responsible for such high-level chiral recognition and selection.« less

Net shaped high performance oxide ceramic parts by selective laser melting

NASA Astrophysics Data System (ADS)

Yves-Christian, Hagedorn; Jan, Wilkes; Wilhelm, Meiners; Konrad, Wissenbach; Reinhart, Poprawe

An additive manufacturing technique (AM) for ceramics, based on Al2O3-ZrO2 powder by means of Selective Laser Melting (SLM) is presented. Pure ceramic powder is completely melted by a laser beam yielding net-shaped specimens of almost 100% densities without any post-processing. Possible crack formation during the build-up process due to thermal stresses is prevented by a high-temperature preheating of above 1600 ∘C. Specimens with fine-grained nano-sized microstructures and flexural strengths of above 500 MPa are produced. The new technology allows for rapid freeform manufacture of complex net-shaped ceramics, thus, exploiting the outstanding mechanical and thermal properties for high-end medical and engineering disciplines.

A high-performance nanoporous Si/Al2O3 foam lithium-ion battery anode fabricated by selective chemical etching of the Al-Si alloy and subsequent thermal oxidation.

PubMed

Hwang, Gaeun; Park, Hyungmin; Bok, Taesoo; Choi, Sinho; Lee, Sungjun; Hwang, Inchan; Choi, Nam-Soon; Seo, Kwanyong; Park, Soojin

2015-03-14

Nanostructured micrometer-sized Al-Si particles are synthesized via a facile selective etching process of Al-Si alloy powder. Subsequent thin Al2O3 layers are introduced on the Si foam surface via a selective thermal wet oxidation process of etched Al-Si particles. The resulting Si/Al2O3 foam anodes exhibit outstanding cycling stability (a capacity retention of 78% after 300 cycles at the C/5 rate) and excellent rate capability.

Cannabis with high δ9-THC contents affects perception and visual selective attention acutely: an event-related potential study.

PubMed

Böcker, K B E; Gerritsen, J; Hunault, C C; Kruidenier, M; Mensinga, Tj T; Kenemans, J L

2010-07-01

Cannabis intake has been reported to affect cognitive functions such as selective attention. This study addressed the effects of exposure to cannabis with up to 69.4mg Delta(9)-tetrahydrocannabinol (THC) on Event-Related Potentials (ERPs) recorded during a visual selective attention task. Twenty-four participants smoked cannabis cigarettes with four doses of THC on four test days in a randomized, double blind, placebo-controlled, crossover study. Two hours after THC exposure the participants performed a visual selective attention task and concomitant ERPs were recorded. Accuracy decreased linearly and reaction times increased linearly with THC dose. However, performance measures and most of the ERP components related specifically to selective attention did not show significant dose effects. Only in relatively light cannabis users the Occipital Selection Negativity decreased linearly with dose. Furthermore, ERP components reflecting perceptual processing, as well as the P300 component, decreased in amplitude after THC exposure. Only the former effect showed a linear dose-response relation. The decrements in performance and ERP amplitudes induced by exposure to cannabis with high THC content resulted from a non-selective decrease in attentional or processing resources. Performance requiring attentional resources, such as vehicle control, may be compromised several hours after smoking cannabis cigarettes containing high doses of THC, as presently available in Europe and Northern America. Copyright 2010 Elsevier Inc. All rights reserved.

Experimental demonstration of selective quantum process tomography on an NMR quantum information processor

NASA Astrophysics Data System (ADS)

Gaikwad, Akshay; Rehal, Diksha; Singh, Amandeep; Arvind, Dorai, Kavita

2018-02-01

We present the NMR implementation of a scheme for selective and efficient quantum process tomography without ancilla. We generalize this scheme such that it can be implemented efficiently using only a set of measurements involving product operators. The method allows us to estimate any element of the quantum process matrix to a desired precision, provided a set of quantum states can be prepared efficiently. Our modified technique requires fewer experimental resources as compared to the standard implementation of selective and efficient quantum process tomography, as it exploits the special nature of NMR measurements to allow us to compute specific elements of the process matrix by a restrictive set of subsystem measurements. To demonstrate the efficacy of our scheme, we experimentally tomograph the processes corresponding to "no operation," a controlled-NOT (CNOT), and a controlled-Hadamard gate on a two-qubit NMR quantum information processor, with high fidelities.

Dissociating the influence of response selection and task anticipation on corticospinal suppression during response preparation.

PubMed

Duque, Julie; Labruna, Ludovica; Cazares, Christian; Ivry, Richard B

2014-12-01

Motor behavior requires selecting between potential actions. The role of inhibition in response selection has frequently been examined in tasks in which participants are engaged in some advance preparation prior to the presentation of an imperative signal. Under such conditions, inhibition could be related to processes associated with response selection, or to more general inhibitory processes that are engaged in high states of anticipation. In Experiment 1, we manipulated the degree of anticipatory preparation. Participants performed a choice reaction time task that required choosing between a movement of the left or right index finger, and used transcranial magnetic stimulation (TMS) to elicit motor evoked potentials (MEPs) in the left hand agonist. In high anticipation blocks, a non-informative cue (e.g., fixation marker) preceded the imperative; in low anticipation blocks, there was no cue and participants were required to divide their attention between two tasks to further reduce anticipation. MEPs were substantially reduced before the imperative signal in high anticipation blocks. In contrast, in low anticipation blocks, MEPs remained unchanged before the imperative signal but showed a marked suppression right after the onset of the imperative. This effect occurred regardless of whether the imperative had signalled a left or right hand response. After this initial inhibition, left MEPs increased when the left hand was selected and remained suppressed when the right hand was selected. We obtained similar results in Experiment 2 except that the persistent left MEP suppression when the left hand was not selected was attenuated when the alternative response involved a non-homologous effector (right foot). These results indicate that, even in the absence of an anticipatory period, inhibitory mechanisms are engaged during response selection, possibly to prevent the occurrence of premature and inappropriate responses during a competitive selection process. Copyright © 2014 Elsevier Ltd. All rights reserved.

Synthesis and Characterization of CuO Nanodisks for High-Sensitive and Selective Ethanol Gas Sensor Applications.

PubMed

Umar, Ahmad; Lee, Jong-Heun; Kumar, Rajesh; Al-Dossary, O

2017-02-01

Herein, the fabrication and characterization of highly sensitive and selective ethanol gas sensor based on CuO nanodisks is reported. The CuO nanodisks were synthesized by facile hydrothermal process and detailed characterization revealed the well-crystallinity, high-purity and high density growth of the prepared material. To fabricate the ethanol gas sensor, the prepared nanodisks were coated on alumina substrate. The fabricated sensor exhibited high-sensitivity and the recorded gas response (resistance-ratio), response time (τ res) and recovery time (τ recov) were 6.2, 119 and 35 s, respectively for 100 ppm of C₂H₅OH at 300 °C. Further, the fabricated sensor shows high selectivity towards ethanol gas compared to H₂ and CO gases.

Distinct Effects of Lexical and Semantic Competition during Picture Naming in Younger Adults, Older Adults, and People with Aphasia

PubMed Central

Britt, Allison E.; Ferrara, Casey; Mirman, Daniel

2016-01-01

Producing a word requires selecting among a set of similar alternatives. When many semantically related items become activated, the difficulty of the selection process is increased. Experiment 1 tested naming of items with either multiple synonymous labels (“Alternate Names,” e.g., gift/present) or closely semantically related but non-equivalent responses (“Near Semantic Neighbors,” e.g., jam/jelly). Picture naming was fastest and most accurate for pictures with only one label (“High Name Agreement”), slower and less accurate in the Alternate Names condition, and slowest and least accurate in the Near Semantic Neighbors condition. These results suggest that selection mechanisms in picture naming operate at two distinct levels of processing: selecting between similar but non-equivalent names requires two selection processes (semantic and lexical), whereas selecting among equivalent names only requires one selection at the lexical level. Experiment 2 examined how these selection mechanisms are affected by normal aging and found that older adults had significantly more difficulty in the Near Semantic Neighbors condition, but not in the Alternate Names condition. This suggests that aging affects semantic processing and selection more strongly than it affects lexical selection. Experiment 3 examined the role of the left inferior frontal gyrus (LIFG) in these selection processes by testing individuals with aphasia secondary to stroke lesions that either affected the LIFG or spared it. Surprisingly, there was no interaction between condition and lesion group: the presence of LIFG damage was not associated with substantively worse naming performance for pictures with multiple acceptable labels. These results are not consistent with a simple view of LIFG as the locus of lexical selection and suggest a more nuanced view of the neural basis of lexical and semantic selection. PMID:27458393

Application of Metal Catalysts for High Selectivity of Glycerol Conversion to Alcohols

DOT National Transportation Integrated Search

2010-11-01

The objective of this project is to determine the applicability of metal-based catalysts and optimize the process conditions for thermochemically producing primary alcohols. Metal catalysts were evaluated for their selectivities for producing alcohol...

Processes for producing low cost, high efficiency silicon solar cells

DOEpatents

Rohatgi, Ajeet; Chen, Zhizhang; Doshi, Parag

1996-01-01

Processes which utilize rapid thermal processing (RTP) are provided for inexpensively producing high efficiency silicon solar cells. The RTP processes preserve minority carrier bulk lifetime .tau. and permit selective adjustment of the depth of the diffused regions, including emitter and back surface field (bsf), within the silicon substrate. Silicon solar cell efficiencies of 16.9% have been achieved. In a first RTP process, an RTP step is utilized to simultaneously diffuse phosphorus and aluminum into the front and back surfaces, respectively, of a silicon substrate. Moreover, an in situ controlled cooling procedure preserves the carrier bulk lifetime .tau. and permits selective adjustment of the depth of the diffused regions. In a second RTP process, both simultaneous diffusion of the phosphorus and aluminum as well as annealing of the front and back contacts are accomplished during the RTP step. In a third RTP process, the RTP step accomplishes simultaneous diffusion of the phosphorus and aluminum, annealing of the contacts, and annealing of a double-layer antireflection/passivation coating SiN/SiO.sub.x.

Selective Dry Etch for Defining Ohmic Contacts for High Performance ZnO TFTs

DTIC Science & Technology

2014-03-27

scale, high-frequency ZnO thin - film transistors (TFTs) could be fabricated. Molybdenum, tantalum, titanium tungsten 10-90, and tungsten metallic contact... thin - film transistor layout utilized in the thesis research . . . . . 42 3.4 Process Flow Diagram for Optical and e-Beam Devices...TFT thin - film transistor TLM transmission line model UV ultra-violet xvii SELECTIVE DRY ETCH FOR DEFINING OHMIC CONTACTS FOR HIGH PERFORMANCE ZnO TFTs

The influence of executive capacity on selective attention and subsequent processing

PubMed Central

Daffner, Kirk R.; Tarbi, Elise C.; Haring, Anna E.; Zhuravleva, Tatyana Y.; Sun, Xue; Rentz, Dorene M.; Holcomb, Phillip J.

2012-01-01

Recent investigations that suggest selective attention (SA) is dependent on top-down control mechanisms lead to the expectation that individuals with high executive capacity (EC) would exhibit more robust neural indices of SA. This prediction was tested by using event-related potentials (ERPs) to examine differences in markers of information processing across 25 subjects divided into two groups based on high vs. average EC, as defined by neuropsychological test scores. Subjects performed an experimental task requiring SA to a specified color. In contrast to expectation, individuals with high and average EC did not differ in the size of ERP indices of SA: the anterior Selection Positivity (SP) and posterior Selection Negativity (SN). However, there were substantial differences between groups in markers of subsequent processing, including the anterior N2 (a measure of attentional control) and the P3a (an index of the orienting of attention). EC predicted speed of processing at both early and late attentional stages. Individuals with lower EC exhibited prolonged SN, P3a, and P3b latencies. However, the delays in carrying out SA operations did not account for subsequent delays in decision making, or explain excessive orienting and reduced attentional control mechanisms in response to stimuli that should have been ignored. SN latency, P3 latency, and the size of the anterior N2 made independent contributions to the variance of EC. In summary, our findings suggest that current views regarding the relationship between top-down control mechanisms and SA may need refinement. PMID:22701415

Highly photoresponsive and wavelength-selective circularly-polarized-light detector based on metal-oxides hetero-chiral thin film.

PubMed

Lee, Seung Hee; Singh, Dhruv Pratap; Sung, Ji Ho; Jo, Moon-Ho; Kwon, Ki Chang; Kim, Soo Young; Jang, Ho Won; Kim, Jong Kyu

2016-01-22

A highly efficient circularly-polarized-light detector with excellent wavelength selectivity is demonstrated with an elegant and simple microelectronics-compatible way. The circularly-polarized-light detector based on a proper combination of the geometry-controlled TiO2-SnO2 hetero-chiral thin film as an effective chiroptical filter and the Si active layer shows excellent chiroptical response with external quantum efficiency as high as 30% and high helicity selectivity of ~15.8% in an intended wavelength range. Furthermore, we demonstrated the ability of manipulating both bandwidth and responsivity of the detector simultaneously in whole visible wavelength range by a precise control over the geometry and materials constituting hetero-chiral thin film. The high efficiency, wavelength selectivity and compatibility with conventional microelectronics processes enabled by the proposed device can result in remarkable developments in highly integrated photonic platforms utilizing chiroptical responses.

Highly photoresponsive and wavelength-selective circularly-polarized-light detector based on metal-oxides hetero-chiral thin film

PubMed Central

Lee, Seung Hee; Singh, Dhruv Pratap; Sung, Ji Ho; Jo, Moon-Ho; Kwon, Ki Chang; Kim, Soo Young; Jang, Ho Won; Kim, Jong Kyu

2016-01-01

A highly efficient circularly-polarized-light detector with excellent wavelength selectivity is demonstrated with an elegant and simple microelectronics-compatible way. The circularly-polarized-light detector based on a proper combination of the geometry-controlled TiO2-SnO2 hetero-chiral thin film as an effective chiroptical filter and the Si active layer shows excellent chiroptical response with external quantum efficiency as high as 30% and high helicity selectivity of ~15.8% in an intended wavelength range. Furthermore, we demonstrated the ability of manipulating both bandwidth and responsivity of the detector simultaneously in whole visible wavelength range by a precise control over the geometry and materials constituting hetero-chiral thin film. The high efficiency, wavelength selectivity and compatibility with conventional microelectronics processes enabled by the proposed device can result in remarkable developments in highly integrated photonic platforms utilizing chiroptical responses. PMID:26795601

Highly photoresponsive and wavelength-selective circularly-polarized-light detector based on metal-oxides hetero-chiral thin film

NASA Astrophysics Data System (ADS)

Lee, Seung Hee; Singh, Dhruv Pratap; Sung, Ji Ho; Jo, Moon-Ho; Kwon, Ki Chang; Kim, Soo Young; Jang, Ho Won; Kim, Jong Kyu

2016-01-01

A highly efficient circularly-polarized-light detector with excellent wavelength selectivity is demonstrated with an elegant and simple microelectronics-compatible way. The circularly-polarized-light detector based on a proper combination of the geometry-controlled TiO2-SnO2 hetero-chiral thin film as an effective chiroptical filter and the Si active layer shows excellent chiroptical response with external quantum efficiency as high as 30% and high helicity selectivity of ~15.8% in an intended wavelength range. Furthermore, we demonstrated the ability of manipulating both bandwidth and responsivity of the detector simultaneously in whole visible wavelength range by a precise control over the geometry and materials constituting hetero-chiral thin film. The high efficiency, wavelength selectivity and compatibility with conventional microelectronics processes enabled by the proposed device can result in remarkable developments in highly integrated photonic platforms utilizing chiroptical responses.

Review of selective laser melting: Materials and applications

NASA Astrophysics Data System (ADS)

Yap, C. Y.; Chua, C. K.; Dong, Z. L.; Liu, Z. H.; Zhang, D. Q.; Loh, L. E.; Sing, S. L.

2015-12-01

Selective Laser Melting (SLM) is a particular rapid prototyping, 3D printing, or Additive Manufacturing (AM) technique designed to use high power-density laser to melt and fuse metallic powders. A component is built by selectively melting and fusing powders within and between layers. The SLM technique is also commonly known as direct selective laser sintering, LaserCusing, and direct metal laser sintering, and this technique has been proven to produce near net-shape parts up to 99.9% relative density. This enables the process to build near full density functional parts and has viable economic benefits. Recent developments of fibre optics and high-power laser have also enabled SLM to process different metallic materials, such as copper, aluminium, and tungsten. Similarly, this has also opened up research opportunities in SLM of ceramic and composite materials. The review presents the SLM process and some of the common physical phenomena associated with this AM technology. It then focuses on the following areas: (a) applications of SLM materials and (b) mechanical properties of SLM parts achieved in research publications. The review is not meant to put a ceiling on the capabilities of the SLM process but to enable readers to have an overview on the material properties achieved by the SLM process so far. Trends in research of SLM are also elaborated in the last section.

Review of selective laser melting: Materials and applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yap, C. Y., E-mail: cyap001@e.ntu.edu.sg; Energy Research Institute @ NTU, Interdisciplinary Graduate School, Nanyang Technological University, 50 Nanyang Avenue, Block S2 - B3a - 01, Singapore 639798; Chua, C. K., E-mail: mckchua@ntu.edu.sg

Selective Laser Melting (SLM) is a particular rapid prototyping, 3D printing, or Additive Manufacturing (AM) technique designed to use high power-density laser to melt and fuse metallic powders. A component is built by selectively melting and fusing powders within and between layers. The SLM technique is also commonly known as direct selective laser sintering, LaserCusing, and direct metal laser sintering, and this technique has been proven to produce near net-shape parts up to 99.9% relative density. This enables the process to build near full density functional parts and has viable economic benefits. Recent developments of fibre optics and high-power lasermore » have also enabled SLM to process different metallic materials, such as copper, aluminium, and tungsten. Similarly, this has also opened up research opportunities in SLM of ceramic and composite materials. The review presents the SLM process and some of the common physical phenomena associated with this AM technology. It then focuses on the following areas: (a) applications of SLM materials and (b) mechanical properties of SLM parts achieved in research publications. The review is not meant to put a ceiling on the capabilities of the SLM process but to enable readers to have an overview on the material properties achieved by the SLM process so far. Trends in research of SLM are also elaborated in the last section.« less

Selective Epitaxial Graphene Growth on SiC via AlN Capping

NASA Astrophysics Data System (ADS)

Zaman, Farhana; Rubio-Roy, Miguel; Moseley, Michael; Lowder, Jonathan; Doolittle, William; Berger, Claire; Dong, Rui; Meindl, James; de Heer, Walt; Georgia Institute of Technology Team

2011-03-01

Electronic-quality graphene is epitaxially grown by graphitization of carbon-face silicon carbide (SiC) by the sublimation of silicon atoms from selected regions uncapped by aluminum nitride (AlN). AlN (deposited by molecular beam epitaxy) withstands high graphitization temperatures of 1420o C, hence acting as an effective capping layer preventing the growth of graphene under it. The AlN is patterned and etched to open up windows onto the SiC surface for subsequent graphitization. Such selective epitaxial growth leads to the formation of high-quality graphene in desired patterns without the need for etching and lithographic patterning of graphene itself. No detrimental contact of the graphene with external chemicals occurs throughout the fabrication-process. The impact of process-conditions on the mobility of graphene is investigated. Graphene hall-bars were fabricated and characterized by scanning Raman spectroscopy, ellipsometry, and transport measurements. This controlled growth of graphene in selected regions represents a viable approach to fabrication of high-mobility graphene as the channel material for fast-switching field-effect transistors.

The study on injection parameters of selected alternative fuels used in diesel engines

NASA Astrophysics Data System (ADS)

Balawender, K.; Kuszewski, H.; Lejda, K.; Lew, K.

2016-09-01

The paper presents selected results concerning fuel charging and spraying process for selected alternative fuels, including regular diesel fuel, rape oil, FAME, blends of these fuels in various proportions, and blends of rape oil with diesel fuel. Examination of the process included the fuel charge measurements. To this end, a set-up for examination of Common Rail-type injection systems was used constructed on the basis of Bosch EPS-815 test bench, from which the high-pressure pump drive system was adopted. For tests concerning the spraying process, a visualisation chamber with constant volume was utilised. The fuel spray development was registered with the use of VisioScope (AVL).

Performance and Selectivity of Ceramic Membranes in the Ultrafiltration of Model Emulsion in Saline

NASA Astrophysics Data System (ADS)

Ćwirko, Konrad; Kalbarczyk-Jedynak, Agnieszka

2017-06-01

Oily wastewaters from different onshore and offshore installations and from maritime transport pose a serious threat to the environment so they must be treated by multistage separation also including membrane processes. The main advantages of such membranes are high performance and selectivity, high resistance for temperature and pressure, resistance for acids, bases and solvents, long service life and for application - significant reduction of industries and transport environmental impact. This work presents the results of the process of separation of oil from the emulsion with NaCl addition. Research was performed with a use of laboratory installation with ceramic 300 kDa membrane. The analysis concerned performance and selectivity of a membrane in the function of time and test results have been subsequently compared with the requirements of the IMO.

Knowledge-Based Manufacturing and Structural Design for a High Speed Civil Transport

NASA Technical Reports Server (NTRS)

Marx, William J.; Mavris, Dimitri N.; Schrage, Daniel P.

1994-01-01

The aerospace industry is currently addressing the problem of integrating manufacturing and design. To address the difficulties associated with using many conventional procedural techniques and algorithms, one feasible way to integrate the two concepts is with the development of an appropriate Knowledge-Based System (KBS). The authors present their reasons for selecting a KBS to integrate design and manufacturing. A methodology for an aircraft producibility assessment is proposed, utilizing a KBS for manufacturing process selection, that addresses both procedural and heuristic aspects of designing and manufacturing of a High Speed Civil Transport (HSCT) wing. A cost model is discussed that would allow system level trades utilizing information describing the material characteristics as well as the manufacturing process selections. Statements of future work conclude the paper.

NbN tunnel junctions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Villegier, J.C.; Goniche, M.; Renard, P.

1985-03-01

All-niobium nitride Josephson junctions have been prepared successfully using a new processing called SNOP: Selective Niobium (Nitride) Overlap Process. Such a process involves the ''trilayer'' deposition on the whole wafer before selective patterning of the electrodes by optically controlled Dry Reactive Ion Etching. Only two photomask levels are need to define an ''overlap'' or a ''cross-type'' junction with a good accuracy. The properties of the niobium nitride films deposited by DC-Magnetron sputtering and the surface oxide growth are analysed. The most critical point to obtain high quality and high gap value junctions resides in the early stage of the NbNmore » counterelectrode growth. Some possibilities to overcome such a handicap exist even if the fabrication needs substrate temperatures below 250/sup 0/C.« less

Data mining and statistical inference in selective laser melting

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kamath, Chandrika

Selective laser melting (SLM) is an additive manufacturing process that builds a complex three-dimensional part, layer-by-layer, using a laser beam to fuse fine metal powder together. The design freedom afforded by SLM comes associated with complexity. As the physical phenomena occur over a broad range of length and time scales, the computational cost of modeling the process is high. At the same time, the large number of parameters that control the quality of a part make experiments expensive. In this paper, we describe ways in which we can use data mining and statistical inference techniques to intelligently combine simulations andmore » experiments to build parts with desired properties. We start with a brief summary of prior work in finding process parameters for high-density parts. We then expand on this work to show how we can improve the approach by using feature selection techniques to identify important variables, data-driven surrogate models to reduce computational costs, improved sampling techniques to cover the design space adequately, and uncertainty analysis for statistical inference. Here, our results indicate that techniques from data mining and statistics can complement those from physical modeling to provide greater insight into complex processes such as selective laser melting.« less

Data mining and statistical inference in selective laser melting

DOE PAGES

Kamath, Chandrika

2016-01-11

Selective laser melting (SLM) is an additive manufacturing process that builds a complex three-dimensional part, layer-by-layer, using a laser beam to fuse fine metal powder together. The design freedom afforded by SLM comes associated with complexity. As the physical phenomena occur over a broad range of length and time scales, the computational cost of modeling the process is high. At the same time, the large number of parameters that control the quality of a part make experiments expensive. In this paper, we describe ways in which we can use data mining and statistical inference techniques to intelligently combine simulations andmore » experiments to build parts with desired properties. We start with a brief summary of prior work in finding process parameters for high-density parts. We then expand on this work to show how we can improve the approach by using feature selection techniques to identify important variables, data-driven surrogate models to reduce computational costs, improved sampling techniques to cover the design space adequately, and uncertainty analysis for statistical inference. Here, our results indicate that techniques from data mining and statistics can complement those from physical modeling to provide greater insight into complex processes such as selective laser melting.« less

Response terminated displays unload selective attention

PubMed Central

Roper, Zachary J. J.; Vecera, Shaun P.

2013-01-01

Perceptual load theory successfully replaced the early vs. late selection debate by appealing to adaptive control over the efficiency of selective attention. Early selection is observed unless perceptual load (p-Load) is sufficiently low to grant attentional “spill-over” to task-irrelevant stimuli. Many studies exploring load theory have used limited display durations that perhaps impose artificial limits on encoding processes. We extended the exposure duration in a classic p-Load task to alleviate temporal encoding demands that may otherwise tax mnemonic consolidation processes. If the load effect arises from perceptual demands alone, then freeing-up available mnemonic resources by extending the exposure duration should have little effect. The results of Experiment 1 falsify this prediction. We observed a reliable flanker effect under high p-Load, response-terminated displays. Next, we orthogonally manipulated exposure duration and task-relevance. Counter-intuitively, we found that the likelihood of observing the flanker effect under high p-Load resides with the duration of the task-relevant array, not the flanker itself. We propose that stimulus and encoding demands interact to produce the load effect. Our account clarifies how task parameters differentially impinge upon cognitive processes to produce attentional “spill-over” by appealing to visual short-term memory as an additional processing bottleneck when stimuli are briefly presented. PMID:24399983

Response terminated displays unload selective attention.

PubMed

Roper, Zachary J J; Vecera, Shaun P

2013-01-01

Perceptual load theory successfully replaced the early vs. late selection debate by appealing to adaptive control over the efficiency of selective attention. Early selection is observed unless perceptual load (p-Load) is sufficiently low to grant attentional "spill-over" to task-irrelevant stimuli. Many studies exploring load theory have used limited display durations that perhaps impose artificial limits on encoding processes. We extended the exposure duration in a classic p-Load task to alleviate temporal encoding demands that may otherwise tax mnemonic consolidation processes. If the load effect arises from perceptual demands alone, then freeing-up available mnemonic resources by extending the exposure duration should have little effect. The results of Experiment 1 falsify this prediction. We observed a reliable flanker effect under high p-Load, response-terminated displays. Next, we orthogonally manipulated exposure duration and task-relevance. Counter-intuitively, we found that the likelihood of observing the flanker effect under high p-Load resides with the duration of the task-relevant array, not the flanker itself. We propose that stimulus and encoding demands interact to produce the load effect. Our account clarifies how task parameters differentially impinge upon cognitive processes to produce attentional "spill-over" by appealing to visual short-term memory as an additional processing bottleneck when stimuli are briefly presented.

Advantages offered by high average power picosecond lasers

NASA Astrophysics Data System (ADS)

Moorhouse, C.

2011-03-01

As electronic devices shrink in size to reduce material costs, device size and weight, thinner material thicknesses are also utilized. Feature sizes are also decreasing, which is pushing manufacturers towards single step laser direct write process as an attractive alternative to conventional, multiple step photolithography processes by eliminating process steps and the cost of chemicals. The fragile nature of these thin materials makes them difficult to machine either mechanically or with conventional nanosecond pulsewidth, Diode Pumped Solids State (DPSS) lasers. Picosecond laser pulses can cut materials with reduced damage regions and selectively remove thin films due to the reduced thermal effects of the shorter pulsewidth. Also, the high repetition rate allows high speed processing for industrial applications. Selective removal of thin films for OLED patterning, silicon solar cells and flat panel displays is discussed, as well as laser cutting of transparent materials with low melting point such as Polyethylene Terephthalate (PET). For many of these thin film applications, where low pulse energy and high repetition rate are required, throughput can be increased by the use of a novel technique to using multiple beams from a single laser source is outlined.

Energetic approach of biomass hydrolysis in supercritical water.

PubMed

Cantero, Danilo A; Vaquerizo, Luis; Mato, Fidel; Bermejo, M Dolores; Cocero, M José

2015-03-01

Cellulose hydrolysis can be performed in supercritical water with a high selectivity of soluble sugars. The process produces high-pressure steam that can be integrated, from an energy point of view, with the whole biomass treating process. This work investigates the integration of biomass hydrolysis reactors with commercial combined heat and power (CHP) schemes, with special attention to reactor outlet streams. The innovation developed in this work allows adequate energy integration possibilities for heating and compression by using high temperature of the flue gases and direct shaft work from the turbine. The integration of biomass hydrolysis with a CHP process allows the selective conversion of biomass into sugars with low heat requirements. Integrating these two processes, the CHP scheme yield is enhanced around 10% by injecting water in the gas turbine. Furthermore, the hydrolysis reactor can be held at 400°C and 23 MPa using only the gas turbine outlet streams. Copyright © 2014 Elsevier Ltd. All rights reserved.

Automated vector selection of SIVQ and parallel computing integration MATLAB™: Innovations supporting large-scale and high-throughput image analysis studies.

PubMed

Cheng, Jerome; Hipp, Jason; Monaco, James; Lucas, David R; Madabhushi, Anant; Balis, Ulysses J

2011-01-01

Spatially invariant vector quantization (SIVQ) is a texture and color-based image matching algorithm that queries the image space through the use of ring vectors. In prior studies, the selection of one or more optimal vectors for a particular feature of interest required a manual process, with the user initially stochastically selecting candidate vectors and subsequently testing them upon other regions of the image to verify the vector's sensitivity and specificity properties (typically by reviewing a resultant heat map). In carrying out the prior efforts, the SIVQ algorithm was noted to exhibit highly scalable computational properties, where each region of analysis can take place independently of others, making a compelling case for the exploration of its deployment on high-throughput computing platforms, with the hypothesis that such an exercise will result in performance gains that scale linearly with increasing processor count. An automated process was developed for the selection of optimal ring vectors to serve as the predicate matching operator in defining histopathological features of interest. Briefly, candidate vectors were generated from every possible coordinate origin within a user-defined vector selection area (VSA) and subsequently compared against user-identified positive and negative "ground truth" regions on the same image. Each vector from the VSA was assessed for its goodness-of-fit to both the positive and negative areas via the use of the receiver operating characteristic (ROC) transfer function, with each assessment resulting in an associated area-under-the-curve (AUC) figure of merit. Use of the above-mentioned automated vector selection process was demonstrated in two cases of use: First, to identify malignant colonic epithelium, and second, to identify soft tissue sarcoma. For both examples, a very satisfactory optimized vector was identified, as defined by the AUC metric. Finally, as an additional effort directed towards attaining high-throughput capability for the SIVQ algorithm, we demonstrated the successful incorporation of it with the MATrix LABoratory (MATLAB™) application interface. The SIVQ algorithm is suitable for automated vector selection settings and high throughput computation.

Remediation of metal-contaminated urban soil using flotation technique.

PubMed

Dermont, G; Bergeron, M; Richer-Laflèche, M; Mercier, G

2010-02-01

A soil washing process using froth flotation technique was evaluated for the removal of arsenic, cadmium, copper, lead, and zinc from a highly contaminated urban soil (brownfield) after crushing of the particle-size fractions >250microm. The metal contaminants were in particulate forms and distributed in all the particle-size fractions. The particle-by-particle study with SEM-EDS showed that Zn was mainly present as sphalerite (ZnS), whereas Cu and Pb were mainly speciated as various oxide/carbonate compounds. The influence of surfactant collector type (non-ionic and anionic), collector dosage, pulp pH, a chemical activation step (sulfidization), particle size, and process time on metal removal efficiency and flotation selectivity was studied. Satisfactory results in metal recovery (42-52%), flotation selectivity (concentration factor>2.5), and volume reduction (>80%) were obtained with anionic collector (potassium amyl xanthate). The transportation mechanisms involved in the separation process (i.e., the true flotation and the mechanical entrainment) were evaluated by the pulp chemistry, the metal speciation, the metal distribution in the particle-size fractions, and the separation selectivity indices of Zn/Ca and Zn/Fe. The investigations showed that a great proportion of metal-containing particles were recovered in the froth layer by entrainment mechanism rather than by true flotation process. The non-selective entrainment mechanism of the fine particles (<20 microm) caused a flotation selectivity drop, especially with a long flotation time (>5 min) and when a high collector dose is used. The intermediate particle-size fraction (20-125 microm) showed the best flotation selectivity. Copyright 2009 Elsevier B.V. All rights reserved.

Explicit attention interferes with selective emotion processing in human extrastriate cortex.

PubMed

Schupp, Harald T; Stockburger, Jessica; Bublatzky, Florian; Junghöfer, Markus; Weike, Almut I; Hamm, Alfons O

2007-02-22

Brain imaging and event-related potential studies provide strong evidence that emotional stimuli guide selective attention in visual processing. A reflection of the emotional attention capture is the increased Early Posterior Negativity (EPN) for pleasant and unpleasant compared to neutral images (approximately 150-300 ms poststimulus). The present study explored whether this early emotion discrimination reflects an automatic phenomenon or is subject to interference by competing processing demands. Thus, emotional processing was assessed while participants performed a concurrent feature-based attention task varying in processing demands. Participants successfully performed the primary visual attention task as revealed by behavioral performance and selected event-related potential components (Selection Negativity and P3b). Replicating previous results, emotional modulation of the EPN was observed in a task condition with low processing demands. In contrast, pleasant and unpleasant pictures failed to elicit increased EPN amplitudes compared to neutral images in more difficult explicit attention task conditions. Further analyses determined that even the processing of pleasant and unpleasant pictures high in emotional arousal is subject to interference in experimental conditions with high task demand. Taken together, performing demanding feature-based counting tasks interfered with differential emotion processing indexed by the EPN. The present findings demonstrate that taxing processing resources by a competing primary visual attention task markedly attenuated the early discrimination of emotional from neutral picture contents. Thus, these results provide further empirical support for an interference account of the emotion-attention interaction under conditions of competition. Previous studies revealed the interference of selective emotion processing when attentional resources were directed to locations of explicitly task-relevant stimuli. The present data suggest that interference of emotion processing by competing task demands is a more general phenomenon extending to the domain of feature-based attention. Furthermore, the results are inconsistent with the notion of effortlessness, i.e., early emotion discrimination despite concurrent task demands. These findings implicate to assess the presumed automatic nature of emotion processing at the level of specific aspects rather than considering automaticity as an all-or-none phenomenon.

Explicit attention interferes with selective emotion processing in human extrastriate cortex

PubMed Central

Schupp, Harald T; Stockburger, Jessica; Bublatzky, Florian; Junghöfer, Markus; Weike, Almut I; Hamm, Alfons O

2007-01-01

Background Brain imaging and event-related potential studies provide strong evidence that emotional stimuli guide selective attention in visual processing. A reflection of the emotional attention capture is the increased Early Posterior Negativity (EPN) for pleasant and unpleasant compared to neutral images (~150–300 ms poststimulus). The present study explored whether this early emotion discrimination reflects an automatic phenomenon or is subject to interference by competing processing demands. Thus, emotional processing was assessed while participants performed a concurrent feature-based attention task varying in processing demands. Results Participants successfully performed the primary visual attention task as revealed by behavioral performance and selected event-related potential components (Selection Negativity and P3b). Replicating previous results, emotional modulation of the EPN was observed in a task condition with low processing demands. In contrast, pleasant and unpleasant pictures failed to elicit increased EPN amplitudes compared to neutral images in more difficult explicit attention task conditions. Further analyses determined that even the processing of pleasant and unpleasant pictures high in emotional arousal is subject to interference in experimental conditions with high task demand. Taken together, performing demanding feature-based counting tasks interfered with differential emotion processing indexed by the EPN. Conclusion The present findings demonstrate that taxing processing resources by a competing primary visual attention task markedly attenuated the early discrimination of emotional from neutral picture contents. Thus, these results provide further empirical support for an interference account of the emotion-attention interaction under conditions of competition. Previous studies revealed the interference of selective emotion processing when attentional resources were directed to locations of explicitly task-relevant stimuli. The present data suggest that interference of emotion processing by competing task demands is a more general phenomenon extending to the domain of feature-based attention. Furthermore, the results are inconsistent with the notion of effortlessness, i.e., early emotion discrimination despite concurrent task demands. These findings implicate to assess the presumed automatic nature of emotion processing at the level of specific aspects rather than considering automaticity as an all-or-none phenomenon. PMID:17316444

Development of a Sensitive Electrochemical Enzymatic Reaction-Based Cholesterol Biosensor Using Nano-Sized Carbon Interdigitated Electrodes Decorated with Gold Nanoparticles

PubMed Central

Sharma, Deepti; Lee, Jongmin; Seo, Junyoung; Shin, Heungjoo

2017-01-01

We developed a versatile and highly sensitive biosensor platform. The platform is based on electrochemical-enzymatic redox cycling induced by selective enzyme immobilization on nano-sized carbon interdigitated electrodes (IDEs) decorated with gold nanoparticles (AuNPs). Without resorting to sophisticated nanofabrication technologies, we used batch wafer-level carbon microelectromechanical systems (C-MEMS) processes to fabricate 3D carbon IDEs reproducibly, simply, and cost effectively. In addition, AuNPs were selectively electrodeposited on specific carbon nanoelectrodes; the high surface-to-volume ratio and fast electron transfer ability of AuNPs enhanced the electrochemical signal across these carbon IDEs. Gold nanoparticle characteristics such as size and morphology were reproducibly controlled by modulating the step-potential and time period in the electrodeposition processes. To detect cholesterol selectively using AuNP/carbon IDEs, cholesterol oxidase (ChOx) was selectively immobilized via the electrochemical reduction of the diazonium cation. The sensitivity of the AuNP/carbon IDE-based biosensor was ensured by efficient amplification of the redox mediators, ferricyanide and ferrocyanide, between selectively immobilized enzyme sites and both of the combs of AuNP/carbon IDEs. The presented AuNP/carbon IDE-based cholesterol biosensor exhibited a wide sensing range (0.005–10 mM) and high sensitivity (~993.91 µA mM−1 cm−2; limit of detection (LOD) ~1.28 µM). In addition, the proposed cholesterol biosensor was found to be highly selective for the cholesterol detection. PMID:28914766

In situ process monitoring in selective laser sintering using optical coherence tomography

NASA Astrophysics Data System (ADS)

Gardner, Michael R.; Lewis, Adam; Park, Jongwan; McElroy, Austin B.; Estrada, Arnold D.; Fish, Scott; Beaman, Joseph J.; Milner, Thomas E.

2018-04-01

Selective laser sintering (SLS) is an efficient process in additive manufacturing that enables rapid part production from computer-based designs. However, SLS is limited by its notable lack of in situ process monitoring when compared with other manufacturing processes. We report the incorporation of optical coherence tomography (OCT) into an SLS system in detail and demonstrate access to surface and subsurface features. Video frame rate cross-sectional imaging reveals areas of sintering uniformity and areas of excessive heat error with high temporal resolution. We propose a set of image processing techniques for SLS process monitoring with OCT and report the limitations and obstacles for further OCT integration with SLS systems.

Stimulus-response compatibility and psychological refractory period effects: implications for response selection

NASA Technical Reports Server (NTRS)

Lien, Mei-Ching; Proctor, Robert W.

2002-01-01

The purpose of this paper was to provide insight into the nature of response selection by reviewing the literature on stimulus-response compatibility (SRC) effects and the psychological refractory period (PRP) effect individually and jointly. The empirical findings and theoretical explanations of SRC effects that have been studied within a single-task context suggest that there are two response-selection routes-automatic activation and intentional translation. In contrast, all major PRP models reviewed in this paper have treated response selection as a single processing stage. In particular, the response-selection bottleneck (RSB) model assumes that the processing of Task 1 and Task 2 comprises two separate streams and that the PRP effect is due to a bottleneck located at response selection. Yet, considerable evidence from studies of SRC in the PRP paradigm shows that the processing of the two tasks is more interactive than is suggested by the RSB model and by most other models of the PRP effect. The major implication drawn from the studies of SRC effects in the PRP context is that response activation is a distinct process from final response selection. Response activation is based on both long-term and short-term task-defined S-R associations and occurs automatically and in parallel for the two tasks. The final response selection is an intentional act required even for highly compatible and practiced tasks and is restricted to processing one task at a time. Investigations of SRC effects and response-selection variables in dual-task contexts should be conducted more systematically because they provide significant insight into the nature of response-selection mechanisms.

Mars Atmospheric Capture and Gas Separation

NASA Technical Reports Server (NTRS)

Muscatello, Anthony; Santiago-Maldonado, Edgardo; Gibson, Tracy; Devor, Robert; Captain, James

2011-01-01

The Mars atmospheric capture and gas separation project is selecting, developing, and demonstrating techniques to capture and purify Martian atmospheric gases for their utilization for the production of hydrocarbons, oxygen, and water in ISRU systems. Trace gases will be required to be separated from Martian atmospheric gases to provide pure C02 to processing elements. In addition, other Martian gases, such as nitrogen and argon, occur in concentrations high enough to be useful as buffer gas and should be captured as welL To achieve these goals, highly efficient gas separation processes will be required. These gas separation techniques are also required across various areas within the ISRU project to support various consumable production processes. The development of innovative gas separation techniques will evaluate the current state-of-the-art for the gas separation required, with the objective to demonstrate and develop light-weight, low-power methods for gas separation. Gas separation requirements include, but are not limited to the selective separation of: (1) methane and water from un-reacted carbon oxides (C02- CO) and hydrogen typical of a Sabatier-type process, (2) carbon oxides and water from unreacted hydrogen from a Reverse Water-Gas Shift process, (3) carbon oxides from oxygen from a trash/waste processing reaction, and (4) helium from hydrogen or oxygen from a propellant scavenging process. Potential technologies for the separations include freezers, selective membranes, selective solvents, polymeric sorbents, zeolites, and new technologies. This paper and presentation will summarize the results of an extensive literature review and laboratory evaluations of candidate technologies for the capture and separation of C02 and other relevant gases.

Temporally selective attention supports speech processing in 3- to 5-year-old children.

PubMed

Astheimer, Lori B; Sanders, Lisa D

2012-01-01

Recent event-related potential (ERP) evidence demonstrates that adults employ temporally selective attention to preferentially process the initial portions of words in continuous speech. Doing so is an effective listening strategy since word-initial segments are highly informative. Although the development of this process remains unexplored, directing attention to word onsets may be important for speech processing in young children who would otherwise be overwhelmed by the rapidly changing acoustic signals that constitute speech. We examined the use of temporally selective attention in 3- to 5-year-old children listening to stories by comparing ERPs elicited by attention probes presented at four acoustically matched times relative to word onsets: concurrently with a word onset, 100 ms before, 100 ms after, and at random control times. By 80 ms, probes presented at and after word onsets elicited a larger negativity than probes presented before word onsets or at control times. The latency and distribution of this effect is similar to temporally and spatially selective attention effects measured in adults and, despite differences in polarity, spatially selective attention effects measured in children. These results indicate that, like adults, preschool aged children modulate temporally selective attention to preferentially process the initial portions of words in continuous speech. Copyright © 2011 Elsevier Ltd. All rights reserved.

Digital selective growth of a ZnO nanowire array by large scale laser decomposition of zinc acetate.

PubMed

Hong, Sukjoon; Yeo, Junyeob; Manorotkul, Wanit; Kang, Hyun Wook; Lee, Jinhwan; Han, Seungyong; Rho, Yoonsoo; Suh, Young Duk; Sung, Hyung Jin; Ko, Seung Hwan

2013-05-07

We develop a digital direct writing method for ZnO NW micro-patterned growth on a large scale by selective laser decomposition of zinc acetate. For ZnO NW growth, by replacing the bulk heating with the scanning focused laser as a fully digital local heat source, zinc acetate crystallites can be selectively activated as a ZnO seed pattern to grow ZnO nanowires locally on a larger area. Together with the selective laser sintering process of metal nanoparticles, more than 10,000 UV sensors have been demonstrated on a 4 cm × 4 cm glass substrate to develop all-solution processible, all-laser mask-less digital fabrication of electronic devices including active layer and metal electrodes without any conventional vacuum deposition, photolithographic process, premade mask, high temperature and vacuum environment.

Fabrication of near-field optical apertures in aluminium by a highly selective corrosion process in the evanescent field.

PubMed

Haefliger, D; Stemmer, A

2003-03-01

A simple, one-step process to fabricate high-quality apertures for scanning near-field optical microscope probes based on aluminium-coated silicon nitride cantilevers is presented. A thin evanescent optical field at a glass-water interface was used to heat the aluminium at the tip apex due to light absorption. The heat induced a breakdown of the passivating oxide layer and local corrosion of the metal, which selectively exposed the front-most part of the probe tip from the aluminium. Apertures with a protruding silicon nitride tip up to 72 nm in height were fabricated. The height of the protrusion was controlled by the extent of the evanescent field, whereas the diameter depended on the geometry of the probe substrate. The corrosion process proved to be self-terminating, yielding highly reproducible tip heights. Near-field optical resolution in a transmission mode of 85 nm was demonstrated.

Electric power processing, distribution and control for advanced aerospace vehicles.

NASA Technical Reports Server (NTRS)

Krausz, A.; Felch, J. L.

1972-01-01

The results of a current study program to develop a rational basis for selection of power processing, distribution, and control configurations for future aerospace vehicles including the Space Station, Space Shuttle, and high-performance aircraft are presented. Within the constraints imposed by the characteristics of power generation subsystems and the load utilization equipment requirements, the power processing, distribution and control subsystem can be optimized by selection of the proper distribution voltage, frequency, and overload/fault protection method. It is shown that, for large space vehicles which rely on static energy conversion to provide electric power, high-voltage dc distribution (above 100 V dc) is preferable to conventional 28 V dc and 115 V ac distribution per MIL-STD-704A. High-voltage dc also has advantages over conventional constant frequency ac systems in many aircraft applications due to the elimination of speed control, wave shaping, and synchronization equipment.

Trait anxiety and impaired control of reflective attention in working memory.

PubMed

Hoshino, Takatoshi; Tanno, Yoshihiko

2016-01-01

The present study investigated whether the control of reflective attention in working memory (WM) is impaired in high trait anxiety individuals. We focused on the consequences of refreshing-a simple reflective process of thinking briefly about a just-activated representation in mind-on the subsequent processing of verbal stimuli. Participants performed a selective refreshing task, in which they initially refreshed or read one word from a three-word set, and then refreshed a non-selected item from the initial phrase or read aloud a new word. High trait anxiety individuals exhibited greater latencies when refreshing a word after experiencing the refreshing of a word from the same list of semantic associates. The same pattern was observed for reading a new word after prior refreshing. These findings suggest that high trait anxiety individuals have difficulty resolving interference from active distractors when directing reflective attention towards contents in WM or processing a visually presented word.

Capture and isotopic exchange method for water and hydrogen isotopes on zeolite catalysts up to technical scale for pre-study of processing highly tritiated water

DOE Office of Scientific and Technical Information (OSTI.GOV)

Michling, R.; Braun, A.; Cristescu, I.

2015-03-15

Highly tritiated water (HTW) may be generated at ITER by various processes and, due to the excessive radio toxicity, the self-radiolysis and the exceedingly corrosive property of HTW, a potential hazard is associated with its storage and process. Therefore, the capture and exchange method for HTW utilizing Molecular Sieve Beds (MSB) was investigated in view of adsorption capacity, isotopic exchange performance and process parameters. For the MSB, different types of zeolite were selected. All zeolite materials were additionally coated with platinum. The following work comprised the selection of the most efficient zeolite candidate based on detailed parametric studies during themore » H{sub 2}/D{sub 2}O laboratory scale exchange experiments (about 25 g zeolite per bed) at the Tritium Laboratory Karlsruhe (TLK). For the zeolite, characterization analytical techniques such as Infrared Spectroscopy, Thermogravimetry and online mass spectrometry were implemented. Followed by further investigation of the selected zeolite catalyst under full technical operation, a MSB (about 22 kg zeolite) was processed with hydrogen flow rates up to 60 mol*h{sup -1} and deuterated water loads up to 1.6 kg in view of later ITER processing of arising HTW. (authors)« less

Optimization of Dimensional accuracy in plasma arc cutting process employing parametric modelling approach

NASA Astrophysics Data System (ADS)

Naik, Deepak kumar; Maity, K. P.

2018-03-01

Plasma arc cutting (PAC) is a high temperature thermal cutting process employed for the cutting of extensively high strength material which are difficult to cut through any other manufacturing process. This process involves high energized plasma arc to cut any conducting material with better dimensional accuracy in lesser time. This research work presents the effect of process parameter on to the dimensional accuracy of PAC process. The input process parameters were selected as arc voltage, standoff distance and cutting speed. A rectangular plate of 304L stainless steel of 10 mm thickness was taken for the experiment as a workpiece. Stainless steel is very extensively used material in manufacturing industries. Linear dimension were measured following Taguchi’s L16 orthogonal array design approach. Three levels were selected to conduct the experiment for each of the process parameter. In all experiments, clockwise cut direction was followed. The result obtained thorough measurement is further analyzed. Analysis of variance (ANOVA) and Analysis of means (ANOM) were performed to evaluate the effect of each process parameter. ANOVA analysis reveals the effect of input process parameter upon leaner dimension in X axis. The results of the work shows that the optimal setting of process parameter values for the leaner dimension on the X axis. The result of the investigations clearly show that the specific range of input process parameter achieved the improved machinability.

Controlled catalytic and thermal sequential pyrolysis and hydrolysis of phenolic resin containing waste streams to sequentially recover monomers and chemicals

DOEpatents

Chum, H.L.; Evans, R.J.

1992-08-04

A process is described for using fast pyrolysis in a carrier gas to convert a waste phenolic resin containing feedstreams in a manner such that pyrolysis of said resins and a given high value monomeric constituent occurs prior to pyrolyses of the resins in other monomeric components therein comprising: selecting a first temperature program range to cause pyrolysis of said resin and a given high value monomeric constituent prior to a temperature range that causes pyrolysis of other monomeric components; selecting, if desired, a catalyst and a support and treating said feedstreams with said catalyst to effect acid or basic catalyzed reaction pathways to maximize yield or enhance separation of said high value monomeric constituent in said first temperature program range to utilize reactive gases such as oxygen and steam in the pyrolysis process to drive the production of specific products; differentially heating said feedstreams at a heat rate within the first temperature program range to provide differential pyrolysis for selective recovery of optimum quantity of said high value monomeric constituent prior to pyrolysis of other monomeric components therein; separating said high value monomeric constituent; selecting a second higher temperature program range to cause pyrolysis of a different high value monomeric constituent of said phenolic resins waste and differentially heating said feedstreams at said higher temperature program range to cause pyrolysis of said different high value monomeric constituent; and separating said different high value monomeric constituent. 11 figs.

Controlled catalytic and thermal sequential pyrolysis and hydrolysis of phenolic resin containing waste streams to sequentially recover monomers and chemicals

DOEpatents

Chum, Helena L.; Evans, Robert J.

1992-01-01

A process of using fast pyrolysis in a carrier gas to convert a waste phenolic resin containing feedstreams in a manner such that pyrolysis of said resins and a given high value monomeric constituent occurs prior to pyrolyses of the resins in other monomeric components therein comprising: selecting a first temperature program range to cause pyrolysis of said resin and a given high value monomeric constituent prior to a temperature range that causes pyrolysis of other monomeric components; selecting, if desired, a catalyst and a support and treating said feedstreams with said catalyst to effect acid or basic catalyzed reaction pathways to maximize yield or enhance separation of said high value monomeric constituent in said first temperature program range to utilize reactive gases such as oxygen and steam in the pyrolysis process to drive the production of specific products; differentially heating said feedstreams at a heat rate within the first temperature program range to provide differential pyrolysis for selective recovery of optimum quantity of said high value monomeric constituent prior to pyrolysis of other monomeric components therein; separating said high value monomeric constituent; selecting a second higher temperature program range to cause pyrolysis of a different high value monomeric constituent of said phenolic resins waste and differentially heating said feedstreams at said higher temperature program range to cause pyrolysis of said different high value monomeric constituent; and separating said different high value monomeric constituent.

How Teacher Selection Practices in a High-Resource, Low-Need Suburban School District Compare with Best Practice Research: A Case Study

ERIC Educational Resources Information Center

Pease, Adam Steven

2012-01-01

The purpose of this study was to develop best practice standards for hiring public school teachers. This standard was developed from the available literature on recruiting, screening, selecting, and hiring high-quality teachers. The targeted and actual hiring processes of a case study district were compared to this teacher hiring standard.…

A Comparative Study on Ni-Based Coatings Prepared by HVAF, HVOF, and APS Methods for Corrosion Protection Applications

NASA Astrophysics Data System (ADS)

Sadeghimeresht, E.; Markocsan, N.; Nylén, P.

2016-12-01

Selection of the thermal spray process is the most important step toward a proper coating solution for a given application as important coating characteristics such as adhesion and microstructure are highly dependent on it. In the present work, a process-microstructure-properties-performance correlation study was performed in order to figure out the main characteristics and corrosion performance of the coatings produced by different thermal spray techniques such as high-velocity air fuel (HVAF), high-velocity oxy fuel (HVOF), and atmospheric plasma spraying (APS). Previously optimized HVOF and APS process parameters were used to deposit Ni, NiCr, and NiAl coatings and compare with HVAF-sprayed coatings with randomly selected process parameters. As the HVAF process presented the best coating characteristics and corrosion behavior, few process parameters such as feed rate and standoff distance (SoD) were investigated to systematically optimize the HVAF coatings in terms of low porosity and high corrosion resistance. The Ni and NiAl coatings with lower porosity and better corrosion behavior were obtained at an average SoD of 300 mm and feed rate of 150 g/min. The NiCr coating sprayed at a SoD of 250 mm and feed rate of 75 g/min showed the highest corrosion resistance among all investigated samples.

Identifying critical success factors for designing selection processes into postgraduate specialty training: the case of UK general practice.

PubMed

Plint, Simon; Patterson, Fiona

2010-06-01

The UK national recruitment process into general practice training has been developed over several years, with incremental introduction of stages which have been piloted and validated. Previously independent processes, which encouraged multiple applications and produced inconsistent outcomes, have been replaced by a robust national process which has high reliability and predictive validity, and is perceived to be fair by candidates and allocates applicants equitably across the country. Best selection practice involves a job analysis which identifies required competencies, then designs reliable assessment methods to measure them, and over the long term ensures that the process has predictive validity against future performance. The general practitioner recruitment process introduced machine markable short listing assessments for the first time in the UK postgraduate recruitment context, and also adopted selection centre workplace simulations. The key success factors have been identified as corporate commitment to the goal of a national process, with gradual convergence maintaining locus of control rather than the imposition of change without perceived legitimate authority.

Selective Laser Melting Produced Ti-6Al-4V: Post-Process Heat Treatments to Achieve Superior Tensile Properties

PubMed Central

Becker, Thorsten H.

2018-01-01

Current post-process heat treatments applied to selective laser melting produced Ti-6Al-4V do not achieve the same microstructure and therefore superior tensile behaviour of thermomechanical processed wrought Ti-6Al-4V. Due to the growing demand for selective laser melting produced parts in industry, research and development towards improved mechanical properties is ongoing. This study is aimed at developing post-process annealing strategies to improve tensile behaviour of selective laser melting produced Ti-6Al-4V parts. Optical and electron microscopy was used to study α grain morphology as a function of annealing temperature, hold time and cooling rate. Quasi-static uniaxial tensile tests were used to measure tensile behaviour of different annealed parts. It was found that elongated α’/α grains can be fragmented into equiaxial grains through applying a high temperature annealing strategy. It is shown that bi-modal microstructures achieve a superior tensile ductility to current heat treated selective laser melting produced Ti-6Al-4V samples. PMID:29342079

Selection of Construction Methods: A Knowledge-Based Approach

PubMed Central

Skibniewski, Miroslaw

2013-01-01

The appropriate selection of construction methods to be used during the execution of a construction project is a major determinant of high productivity, but sometimes this selection process is performed without the care and the systematic approach that it deserves, bringing negative consequences. This paper proposes a knowledge management approach that will enable the intelligent use of corporate experience and information and help to improve the selection of construction methods for a project. Then a knowledge-based system to support this decision-making process is proposed and described. To define and design the system, semistructured interviews were conducted within three construction companies with the purpose of studying the way that the method' selection process is carried out in practice and the knowledge associated with it. A prototype of a Construction Methods Knowledge System (CMKS) was developed and then validated with construction industry professionals. As a conclusion, the CMKS was perceived as a valuable tool for construction methods' selection, by helping companies to generate a corporate memory on this issue, reducing the reliance on individual knowledge and also the subjectivity of the decision-making process. The described benefits as provided by the system favor a better performance of construction projects. PMID:24453925

Using Bayesian Inference Framework towards Identifying Gas Species and Concentration from High Temperature Resistive Sensor Array Data

DOE PAGES

Liu, Yixin; Zhou, Kai; Lei, Yu

2015-01-01

High temperature gas sensors have been highly demanded for combustion process optimization and toxic emissions control, which usually suffer from poor selectivity. In order to solve this selectivity issue and identify unknown reducing gas species (CO, CH 4 , and CH 8 ) and concentrations, a high temperature resistive sensor array data set was built in this study based on 5 reported sensors. As each sensor showed specific responses towards different types of reducing gas with certain concentrations, based on which calibration curves were fitted, providing benchmark sensor array response database, then Bayesian inference framework was utilized to process themore » sensor array data and build a sample selection program to simultaneously identify gas species and concentration, by formulating proper likelihood between input measured sensor array response pattern of an unknown gas and each sampled sensor array response pattern in benchmark database. This algorithm shows good robustness which can accurately identify gas species and predict gas concentration with a small error of less than 10% based on limited amount of experiment data. These features indicate that Bayesian probabilistic approach is a simple and efficient way to process sensor array data, which can significantly reduce the required computational overhead and training data.« less

A DFT study and micro-kinetic analysis of acetylene selective hydrogenation on Pd-doped Cu(111) surfaces

NASA Astrophysics Data System (ADS)

Ma, Ling-Ling; Lv, Cun-Qin; Wang, Gui-Chang

2017-07-01

Semi-hydrogenation of acetylene in a hydrogen-rich stream is an industrially important process. Inspired by the recent experiments that Cu(111) surface doped by a small number of Pd atoms can exhibit excellent catalytic performance toward the dissociation of H2 molecule as well as the high selective hydrogenation of acetylene as compared with pure Cu and Pd metal alone at low-temperature, here we performed systematic first-principles calculations to investigate the corresponding reaction mechanism related to the acetylene hydrogenation processes on single atom alloys (SAAs) and monolayer Pd/Cu(111) (i.e.,1.00 ML Pd/Cu(111)) model catalysts in detail, and to explore the possible factors controlling the high selectivity on SAAs. Our results clearly demonstrate that the SAA catalyst has higher selectivity for the ethylene formation than that of 1.00 ML Pd/Cu(111), and lower activity for the acetylene conversion compared with that of 1.00 ML Pd/Cu(111). The relatively high selectivity on SAA is mainly due to the facile desorption of ethylene and moderate activity in the dissociation of molecular H2. The main factor which lowers the selectivity towards the ethylene formation on 1.00 ML Pd/Cu(111) is that this system has a higher capacity to promote the breaking of Csbnd H/Csbnd C bonds, which leads to the formation of carbonaceous deposits and polymers such as benzene, and thus reduces the selectivity for the ethylene formation. Meanwhile, it was found that the desorption energy of ethylene on these two surfaces was smaller than the energy barrier of further hydrogenation, which results in the absence of ethane on these two systems. Micro-kinetic model analysis provides a further valuable insight into the evidence for the key factors controlling the catalytic activity and selectivity towards the selective hydrogenation of acetylene. Our findings may help people to design a highly selective hydrogenation catalyst by controlling the balance between the H2 dissociation and Csbnd H/Csbnd C bond broken processes, and a good catalyst should be the one with the modest catalytic activity in the activation of molecular H2. At the same time, the present work provides an extremely significant mechanism of acetylene trimerization to form benzene and carbon formation.

Selective and Catalyst-free Oxidation of D-Glucose to D-Glucuronic acid induced by High-Frequency Ultrasound

NASA Astrophysics Data System (ADS)

Amaniampong, Prince N.; Karam, Ayman; Trinh, Quang Thang; Xu, Kai; Hirao, Hajime; Jérôme, François; Chatel, Gregory

2017-01-01

This systematic experimental investigation reveals that high-frequency ultrasound irradiation (550 kHz) induced oxidation of D-glucose to glucuronic acid in excellent yield without assistance of any (bio)catalyst. Oxidation is induced thanks to the in situ production of radical species in water. Experiments show that the dissolved gases play an important role in governing the nature of generated radical species and thus the selectivity for glucuronic acid. Importantly, this process yields glucuronic acid instead of glucuronate salt typically obtained via conventional (bio)catalyst routes, which is of huge interest in respect of downstream processing. Investigations using disaccharides revealed that radicals generated by high frequency ultrasound were also capable of promoting tandem hydrolysis/oxidation reactions.

Tribological synthesis method for producing low-friction surface film coating

DOEpatents

Ajayi, Oyelayo O.; Lorenzo-Martin, Maria De La; Fenske, George R.

2016-10-25

An article of method of manufacture of a low friction tribological film on a substrate. The article includes a substrate of a steel or ceramic which has been tribologically processed with a lubricant containing selected additives and the additives, temperature, load and time of processing can be selectively controlled to bias formation of a film on the substrate where the film is an amorphous structure exhibiting highly advantageous low friction properties.

Highly Selective Membranes For The Separation Of Organic Vapors Using Super-Glassy Polymers

DOEpatents

Pinnau, Ingo; Lokhandwala, Kaaeid; Nguyen, Phuong; Segelke, Scott

1997-11-18

A process for separating hydrocarbon gases of low boiling point, particularly methane, ethane and ethylene, from nitrogen. The process is performed using a membrane made from a super-glassy material. The gases to be separated are mixed with a condensable gas, such as a C.sub.3+ hydrocarbon. In the presence of the condensable gas, improved selectivity for the low-boiling-point hydrocarbon gas over nitrogen is achieved.

Reversal of alcohol-induced effects on response control due to changes in proprioceptive information processing.

PubMed

Stock, Ann-Kathrin; Mückschel, Moritz; Beste, Christian

2017-01-01

Recent research has drawn interest to the effects of binge drinking on response selection. However, choosing an appropriate response is a complex endeavor that usually requires us to process and integrate several streams of information. One of them is proprioceptive information about the position of limbs. As to now, it has however remained elusive how binge drinking affects the processing of proprioceptive information during response selection and control in healthy individuals. We investigated this question using neurophysiological (EEG) techniques in a response selection task, where we manipulated proprioceptive information. The results show a reversal of alcohol-induced effects on response control due to changes in proprioceptive information processing. The most likely explanation for this finding is that proprioceptive information does not seem to be properly integrated in response selection processes during acute alcohol intoxication as found in binge drinking. The neurophysiological data suggest that processes related to the preparation and execution of the motor response, but not upstream processes related to conflict monitoring and spatial attentional orienting, underlie these binge drinking-dependent modulations. Taken together, the results show that even high doses of alcohol have very specific effects within the cascade of neurophysiological processes underlying response control and the integration of proprioceptive information during this process. © 2015 Society for the Study of Addiction.

[Sex differences in relationship between creativity and hemispheric information processing in global and local levels].

PubMed

Razumnikova, O M; Vol'f, N V

2012-01-01

Sex differences in creativity related global-local hemispheric selective processing were examined by hierarchical letter presenting in conditions of their perception and comparison. Fifty-six right-handed males and 68 females (aged 17-22 years) participated in the experiments. Originality-imagery was assessed by a computer-based Torrance 'Incomplete Figures' test software. Verbal creativity was valued by original sentence using of three nouns from remote semantic categories. The results show that irrespectively of the sex factor and the type of creative thinking, its originality is provided by high speed of right-hemispheric processes of information selection on the global level and delay in the interhemispheric communication. Relationships between originality of ideas and hemispheric attentional characteristics are presented mostly in men while verbal creative problem solving, and in women while figurative original thinking. Originality of verbal activity in men is more associated with success of selective processes in the left hemisphere, but in women--with selective functions of both hemispheres. Figurative thinking in men is less related to hemispheric characteristics of attention compared with women. Increase of figurative originality in women is accompanied acceleration of processes of selection of the information in the right hemisphere, and also higher efficiency of local attention as well as speeds ofglobal processing in the left hemisphere.

Selection of Yeast Strains for Tequila Fermentation Based on Growth Dynamics in Combined Fructose and Ethanol Media.

PubMed

Aldrete-Tapia, J A; Miranda-Castilleja, D E; Arvizu-Medrano, S M; Hernández-Iturriaga, M

2018-02-01

The high concentration of fructose in agave juice has been associated with reduced ethanol tolerance of commercial yeasts used for tequila production and low fermentation yields. The selection of autochthonous strains, which are better adapted to agave juice, could improve the process. In this study, a 2-step selection process of yeasts isolated from spontaneous fermentations for tequila production was carried out based on analysis of the growth dynamics in combined conditions of high fructose and ethanol. First, yeast isolates (605) were screened to identify strains tolerant to high fructose (20%) and to ethanol (10%), yielding 89 isolates able to grow in both conditions. From the 89 isolates, the growth curves under 8 treatments of combined fructose (from 20% to 5%) and ethanol (from 0% to 10%) were obtained, and the kinetic parameters were analyzed with principal component analysis and k-means clustering. The resulting yeast strain groups corresponded to the fast, medium and slow growers. A second clustering of only the fast growers led to the selection of 3 Saccharomyces strains (199, 230, 231) that were able to grow rapidly in 4 out of the 8 conditions evaluated. This methodology differentiated strains phenotypically and could be further used for strain selection in other processes. A method to select yeast strains for fermentation taking into account the natural differences of yeast isolates. This methodology is based on the cell exposition to combinations of sugar and ethanol, which are the most important stress factors in fermentation. This strategy will help to identify the most tolerant strain that could improve ethanol yield and reduce fermentation time. © 2018 Institute of Food Technologists®.

Thermodynamic analysis of the selective chlorination of electric arc furnace dust.

PubMed

Pickles, C A

2009-07-30

The remelting of automobile scrap in an electric arc furnace (EAF) results in the production of a dust, which contains high concentrations of the oxides of zinc, iron, calcium and other metals. Typically, the lead and zinc are of commercial value, while the other metals are not worth recovering. At the present time, EAF dusts are treated in high temperature Waelz rotary kiln-type processes, where the lead and zinc oxides are selectively reduced and simultaneously reoxidized and a crude zinc oxide is produced. Another alternative processing route is selective chlorination, in which the non-ferrous metals are preferentially chlorinated to their gaseous chlorides and in this manner separated from the iron. In the present research, a detailed thermodynamic analysis of this chlorination process has been performed and the following factors were investigated; temperature, amount of chlorine, lime content, silica content, presence of an inert gas and the oxygen potential. High lead and zinc recoveries as gaseous chlorides could be achieved but some of the iron oxide was also chlorinated. Additionally, the calcium oxide in the dust consumes chlorine, but this can be minimized by adding silica, which results in the formation of stable calcium silicates. The optimum conditions were determined for a typical dust composition. The selectivities achieved with chlorination were lower than those for reduction, as reported in the literature, but there are other advantages such as the potential recovery of copper.

High pressure processing with hot sauce flavoring enhances sensory quality for raw oysters (Crassostrea virginica)

USDA-ARS?s Scientific Manuscript database

This study evaluated the feasibility of flavoring raw oysters by placing them under pressure in the presence of selected flavorings. Hand-shucked raw oysters were processed at high pressure (600 MPa), in the presence or absence of (Sriracha®) flavoring, and evaluated by a trained sensory panel 3 an...

Single Step Laser Transfer and Laser Curing of Ag NanoWires: A Digital Process for the Fabrication of Flexible and Transparent Microelectrodes.

PubMed

Zacharatos, Filimon; Karvounis, Panagiotis; Theodorakos, Ioannis; Hatziapostolou, Antonios; Zergioti, Ioanna

2018-06-19

Ag nanowire (NW) networks have exquisite optical and electrical properties which make them ideal candidate materials for flexible transparent conductive electrodes. Despite the compatibility of Ag NW networks with laser processing, few demonstrations of laser fabricated Ag NW based components currently exist. In this work, we report on a novel single step laser transferring and laser curing process of micrometer sized pixels of Ag NW networks on flexible substrates. This process relies on the selective laser heating of the Ag NWs induced by the laser pulse energy and the subsequent localized melting of the polymeric substrate. We demonstrate that a single laser pulse can induce both transfer and curing of the Ag NW network. The feasibility of the process is confirmed experimentally and validated by Finite Element Analysis simulations, which indicate that selective heating is carried out within a submicron-sized heat affected zone. The resulting structures can be utilized as fully functional flexible transparent electrodes with figures of merit even higher than 100. Low sheet resistance (<50 Ohm/sq) and high visible light transparency (>90%) make the reported process highly desirable for a variety of applications, including selective heating or annealing of nanocomposite materials and laser processing of nanostructured materials on a large variety of optically transparent substrates, such as Polydimethylsiloxane (PDMS).

Forest fragmentation and selective logging have inconsistent effects on multiple animal-mediated ecosystem processes in a tropical forest.

PubMed

Schleuning, Matthias; Farwig, Nina; Peters, Marcell K; Bergsdorf, Thomas; Bleher, Bärbel; Brandl, Roland; Dalitz, Helmut; Fischer, Georg; Freund, Wolfram; Gikungu, Mary W; Hagen, Melanie; Garcia, Francisco Hita; Kagezi, Godfrey H; Kaib, Manfred; Kraemer, Manfred; Lung, Tobias; Naumann, Clas M; Schaab, Gertrud; Templin, Mathias; Uster, Dana; Wägele, J Wolfgang; Böhning-Gaese, Katrin

2011-01-01

Forest fragmentation and selective logging are two main drivers of global environmental change and modify biodiversity and environmental conditions in many tropical forests. The consequences of these changes for the functioning of tropical forest ecosystems have rarely been explored in a comprehensive approach. In a Kenyan rainforest, we studied six animal-mediated ecosystem processes and recorded species richness and community composition of all animal taxa involved in these processes. We used linear models and a formal meta-analysis to test whether forest fragmentation and selective logging affected ecosystem processes and biodiversity and used structural equation models to disentangle direct from biodiversity-related indirect effects of human disturbance on multiple ecosystem processes. Fragmentation increased decomposition and reduced antbird predation, while selective logging consistently increased pollination, seed dispersal and army-ant raiding. Fragmentation modified species richness or community composition of five taxa, whereas selective logging did not affect any component of biodiversity. Changes in the abundance of functionally important species were related to lower predation by antbirds and higher decomposition rates in small forest fragments. The positive effects of selective logging on bee pollination, bird seed dispersal and army-ant raiding were direct, i.e. not related to changes in biodiversity, and were probably due to behavioural changes of these highly mobile animal taxa. We conclude that animal-mediated ecosystem processes respond in distinct ways to different types of human disturbance in Kakamega Forest. Our findings suggest that forest fragmentation affects ecosystem processes indirectly by changes in biodiversity, whereas selective logging influences processes directly by modifying local environmental conditions and resource distributions. The positive to neutral effects of selective logging on ecosystem processes show that the functionality of tropical forests can be maintained in moderately disturbed forest fragments. Conservation concepts for tropical forests should thus include not only remaining pristine forests but also functionally viable forest remnants.

Forest Fragmentation and Selective Logging Have Inconsistent Effects on Multiple Animal-Mediated Ecosystem Processes in a Tropical Forest

PubMed Central

Schleuning, Matthias; Farwig, Nina; Peters, Marcell K.; Bergsdorf, Thomas; Bleher, Bärbel; Brandl, Roland; Dalitz, Helmut; Fischer, Georg; Freund, Wolfram; Gikungu, Mary W.; Hagen, Melanie; Garcia, Francisco Hita; Kagezi, Godfrey H.; Kaib, Manfred; Kraemer, Manfred; Lung, Tobias; Schaab, Gertrud; Templin, Mathias; Uster, Dana; Wägele, J. Wolfgang; Böhning-Gaese, Katrin

2011-01-01

Forest fragmentation and selective logging are two main drivers of global environmental change and modify biodiversity and environmental conditions in many tropical forests. The consequences of these changes for the functioning of tropical forest ecosystems have rarely been explored in a comprehensive approach. In a Kenyan rainforest, we studied six animal-mediated ecosystem processes and recorded species richness and community composition of all animal taxa involved in these processes. We used linear models and a formal meta-analysis to test whether forest fragmentation and selective logging affected ecosystem processes and biodiversity and used structural equation models to disentangle direct from biodiversity-related indirect effects of human disturbance on multiple ecosystem processes. Fragmentation increased decomposition and reduced antbird predation, while selective logging consistently increased pollination, seed dispersal and army-ant raiding. Fragmentation modified species richness or community composition of five taxa, whereas selective logging did not affect any component of biodiversity. Changes in the abundance of functionally important species were related to lower predation by antbirds and higher decomposition rates in small forest fragments. The positive effects of selective logging on bee pollination, bird seed dispersal and army-ant raiding were direct, i.e. not related to changes in biodiversity, and were probably due to behavioural changes of these highly mobile animal taxa. We conclude that animal-mediated ecosystem processes respond in distinct ways to different types of human disturbance in Kakamega Forest. Our findings suggest that forest fragmentation affects ecosystem processes indirectly by changes in biodiversity, whereas selective logging influences processes directly by modifying local environmental conditions and resource distributions. The positive to neutral effects of selective logging on ecosystem processes show that the functionality of tropical forests can be maintained in moderately disturbed forest fragments. Conservation concepts for tropical forests should thus include not only remaining pristine forests but also functionally viable forest remnants. PMID:22114695

Testing the cultural group selection hypothesis in Northern Ghana and Oaxaca.

PubMed

Acedo-Carmona, Cristina; Gomila, Antoni

2016-01-01

We examine the cultural group selection (CGS) hypothesis in light of our fieldwork in Northern Ghana and Oaxaca, highly multi-ethnic regions. Our evidence fails to corroborate two central predictions of the hypothesis: that the cultural group is the unit of evolution, and that cultural homogenization is to be expected as the outcome of a selective process.

Probe Into the Influence of Crosslinking on CO2 Permeation of Membranes

PubMed Central

Li, Jinghui; Chen, Zhuo; Umar, Ahmad; Liu, Yang; Shang, Ying; Zhang, Xiaokai; Wang, Yao

2017-01-01

Crosslinking is an effective way to fabricate high-selective CO2 separation membranes because of its unique crosslinking framework. Thus, it is essentially significant to study the influence of crosslinking degree on the permeation selectivities of CO2. Herein, we report a successful and facile synthesis of a series of polyethylene oxide (PEO)-based diblock copolymers (BCP) incorporated with an unique UV-crosslinkable chalcone unit using Reversible Addition-Fragmentation Chain Transfer Polymerization (RAFT) process. The membranes of as-prepared BCPs show superior carbon dioxide (CO2) separation properties as compared to nitrogen (N2) after UV-crosslinking. Importantly, the influence of different proportions of crosslinked chalcone on CO2 selectivities was systematically investigated, which revealed that CO2 selectivities increased obviously with the enhancement of chalcone fractions within a certain limit. Further, the CO2 selectivities of block copolymer with the best block proportion was studied by varying the crosslinking time which confirmed that the high crosslinking degree exhibited a better CO2/N2 (αCO2/N2) selectivities. A possible mechanism model revealing that the crosslinking degree played a key role in the gas separation process was also proposed. PMID:28051190

Probe Into the Influence of Crosslinking on CO2 Permeation of Membranes

NASA Astrophysics Data System (ADS)

Li, Jinghui; Chen, Zhuo; Umar, Ahmad; Liu, Yang; Shang, Ying; Zhang, Xiaokai; Wang, Yao

2017-01-01

Crosslinking is an effective way to fabricate high-selective CO2 separation membranes because of its unique crosslinking framework. Thus, it is essentially significant to study the influence of crosslinking degree on the permeation selectivities of CO2. Herein, we report a successful and facile synthesis of a series of polyethylene oxide (PEO)-based diblock copolymers (BCP) incorporated with an unique UV-crosslinkable chalcone unit using Reversible Addition-Fragmentation Chain Transfer Polymerization (RAFT) process. The membranes of as-prepared BCPs show superior carbon dioxide (CO2) separation properties as compared to nitrogen (N2) after UV-crosslinking. Importantly, the influence of different proportions of crosslinked chalcone on CO2 selectivities was systematically investigated, which revealed that CO2 selectivities increased obviously with the enhancement of chalcone fractions within a certain limit. Further, the CO2 selectivities of block copolymer with the best block proportion was studied by varying the crosslinking time which confirmed that the high crosslinking degree exhibited a better CO2/N2 (αCO2/N2) selectivities. A possible mechanism model revealing that the crosslinking degree played a key role in the gas separation process was also proposed.

A fluorescent turn-on H2S-responsive probe: design, synthesis and application.

PubMed

Zhang, Yufeng; Chen, Haiyan; Chen, Dan; Wu, Di; Chen, Xiaoqiang; Liu, Sheng Hua; Yin, Jun

2015-10-14

Hydrogen sulfide (H2S) is considered as the third signaling molecule in vivo and it plays an important role in various physiological processes and pathological processes in vivo, such as vasodilation, apoptosis, neurotransmission, ischemia/reperfusion-induced injury, insulin secretion and inflammation. Developing a highly selective and sensitive method that can detect H2S in the biological system is very important. In this work, a colorimetric and "turn-on" fluorescent probe is developed. Furthermore, this probe displays a highly selective response to H2S in aqueous solution and possesses good capability for bioimaging H2S without interference in living cells. The results suggest that a H2S-selective probe has good water-solubility, biocompatibility and cell-penetrability and can serve as an efficient tool for probing H2S in the cell level.

Highly selective dry etching of GaP in the presence of AlxGa1–xP with a SiCl4/SF6 plasma

NASA Astrophysics Data System (ADS)

Hönl, Simon; Hahn, Herwig; Baumgartner, Yannick; Czornomaz, Lukas; Seidler, Paul

2018-05-01

We present an inductively coupled-plasma reactive-ion etching process that simultaneously provides both a high etch rate and unprecedented selectivity for gallium phosphide (GaP) in the presence of aluminum gallium phosphide (AlxGa1–xP). Utilizing mixtures of silicon tetrachloride (SiCl4) and sulfur hexafluoride (SF6), selectivities exceeding 2700:1 are achieved at GaP etch rates above 3000 nm min‑1. A design of experiments has been employed to investigate the influence of the inductively coupled-plasma power, the chamber pressure, the DC bias and the ratio of SiCl4 to SF6. The process enables the use of thin AlxGa1–xP stop layers even at aluminum contents of a few percent.

Paradoxical self-esteem and selectivity in the processing of social information.

PubMed

Tafarodi, R W

1998-05-01

Paradoxical self-esteem is defined as contrasting levels of self-liking and self-competence. Consideration of the social and motivational implications of this uncommon form of self-esteem suggests that heightened selectivity in the processing of social information may be behind its persistence. Two experiments were conducted to confirm the prediction of heightened selectivity in paradoxicals. As expected, those paradoxically low in self-liking were more negatively biased in their memory for personality feedback (Study 1) and interpretation of valuatively ambiguous phrases (Study 2) than were their counterparts who shared the same low self-liking but were also low in self-competence. Symmetrical with this result, those paradoxically high in self-liking exhibited a heightened positive bias relative to those who were high in both self-liking and self-competence. The findings are discussed in relation to attitudes and motivation.

Selective electroless plating of 3D-printed plastic structures for three-dimensional microwave metamaterials

NASA Astrophysics Data System (ADS)

Ishikawa, Atsushi; Kato, Taiki; Takeyasu, Nobuyuki; Fujimori, Kazuhiro; Tsuruta, Kenji

2017-10-01

A technique of selective electroless plating onto PLA-ABS (Polylactic Acid-Acrylonitrile Butadiene Styrene) composite structures fabricated by three-dimensional (3D) printing is demonstrated to construct 3D microwave metamaterials. The reducing activity of the PLA surface is selectively enhanced by the chemical modification involving Sn2+ in a simple wet process, thereby forming a highly conductive Ag-plated membrane only onto the PLA surface. The fabricated metamaterial composed of Ag-plated PLA and non-plated ABS parts is characterized experimentally and numerically to demonstrate the important bi-anisotropic microwave responses arising from the 3D nature of metallodielectric structures. Our approach based on a simple wet chemical process allows for the creation of highly complex 3D metal-insulator structures, thus paving the way toward the sophisticated microwave applications of the 3D printing technology.

Assortative and dissortative priorities for game interaction and strategy adaptation significantly bolster network reciprocity in the prisoner’s dilemma

NASA Astrophysics Data System (ADS)

Tanimoto, Jun

2014-05-01

In 2 × 2 prisoner’s dilemma games, network reciprocity is one mechanism for adding social viscosity, which leads to cooperative equilibrium. Here we show that combining the process for selecting a gaming partner with the process for selecting an adaptation partner significantly enhances cooperation, even though such selection processes require additional costs to collect further information concerning which neighbor should be chosen. Based on elaborate investigations of the dynamics generated by our model, we find that high levels of cooperation result from two kinds of behavior: cooperators tend to interact with cooperators to prevent being exploited by defectors and defectors tend to choose cooperators to exploit despite the possibility that some defectors convert to cooperators.

Politics of Textbook Selection.

ERIC Educational Resources Information Center

Keith, Sherry

The process of determining textbook content and selecting textbooks for classroom use in public schools throughout America is highly political and raises many fundamental questions about the relationship between education as a social enterprise and other aspects of society--economic, ideological, political, and legal. This study focuses on three…

Selective synthesis of secondary amines by Pt nanowire catalyzed reductive amination of aldehydes and ketones with ammonia.

PubMed

Qi, Fenqiang; Hu, Lei; Lu, Shuanglong; Cao, Xueqin; Gu, Hongwei

2012-10-07

The process of the reductive amination of aldehydes or ketones in the presence of ammonia using unsupported ultra-thin Pt nanowires has been developed. This catalytic system shows high activity and selectivity under mild reaction conditions.

Processing Device for High-Speed Execution of an Xrisc Computer Program

NASA Technical Reports Server (NTRS)

Ng, Tak-Kwong (Inventor); Mills, Carl S. (Inventor)

2016-01-01

A processing device for high-speed execution of a computer program is provided. A memory module may store one or more computer programs. A sequencer may select one of the computer programs and controls execution of the selected program. A register module may store intermediate values associated with a current calculation set, a set of output values associated with a previous calculation set, and a set of input values associated with a subsequent calculation set. An external interface may receive the set of input values from a computing device and provides the set of output values to the computing device. A computation interface may provide a set of operands for computation during processing of the current calculation set. The set of input values are loaded into the register and the set of output values are unloaded from the register in parallel with processing of the current calculation set.

Selective catalytic two-step process for ethylene glycol from carbon monoxide

PubMed Central

Dong, Kaiwu; Elangovan, Saravanakumar; Sang, Rui; Spannenberg, Anke; Jackstell, Ralf; Junge, Kathrin; Li, Yuehui; Beller, Matthias

2016-01-01

Upgrading C1 chemicals (for example, CO, CO/H2, MeOH and CO2) with C–C bond formation is essential for the synthesis of bulk chemicals. In general, these industrially important processes (for example, Fischer Tropsch) proceed at drastic reaction conditions (>250 °C; high pressure) and suffer from low selectivity, which makes high capital investment necessary and requires additional purifications. Here, a different strategy for the preparation of ethylene glycol (EG) via initial oxidative coupling and subsequent reduction is presented. Separating coupling and reduction steps allows for a completely selective formation of EG (99%) from CO. This two-step catalytic procedure makes use of a Pd-catalysed oxycarbonylation of amines to oxamides at room temperature (RT) and subsequent Ru- or Fe-catalysed hydrogenation to EG. Notably, in the first step the required amines can be efficiently reused. The presented stepwise oxamide-mediated coupling provides the basis for a new strategy for selective upgrading of C1 chemicals. PMID:27377550

Selective visual scaling of time-scale processes facilitates broadband learning of isometric force frequency tracking.

PubMed

King, Adam C; Newell, Karl M

2015-10-01

The experiment investigated the effect of selectively augmenting faster time scales of visual feedback information on the learning and transfer of continuous isometric force tracking tasks to test the generality of the self-organization of 1/f properties of force output. Three experimental groups tracked an irregular target pattern either under a standard fixed gain condition or with selectively enhancement in the visual feedback display of intermediate (4-8 Hz) or high (8-12 Hz) frequency components of the force output. All groups reduced tracking error over practice, with the error lowest in the intermediate scaling condition followed by the high scaling and fixed gain conditions, respectively. Selective visual scaling induced persistent changes across the frequency spectrum, with the strongest effect in the intermediate scaling condition and positive transfer to novel feedback displays. The findings reveal an interdependence of the timescales in the learning and transfer of isometric force output frequency structures consistent with 1/f process models of the time scales of motor output variability.

Numerical simulation of complex part manufactured by selective laser melting process

NASA Astrophysics Data System (ADS)

Van Belle, Laurent

2017-10-01

Selective Laser Melting (SLM) process belonging to the family of the Additive Manufacturing (AM) technologies, enable to build parts layer by layer, from metallic powder and a CAD model. Physical phenomena that occur in the process have the same issues as conventional welding. Thermal gradients generate significant residual stresses and distortions in the parts. Moreover, the large and complex parts to manufacturing, accentuate the undesirable effects. Therefore, it is essential for manufacturers to offer a better understanding of the process and to ensure production reliability of parts with high added value. This paper focuses on the simulation of manufacturing turbine by SLM process in order to calculate residual stresses and distortions. Numerical results will be presented.

Mesoporous structured MIPs@CDs fluorescence sensor for highly sensitive detection of TNT.

PubMed

Xu, Shoufang; Lu, Hongzhi

2016-11-15

A facile strategy was developed to prepare mesoporous structured molecularly imprinted polymers capped carbon dots (M-MIPs@CDs) fluorescence sensor for highly sensitive and selective determination of TNT. The strategy using amino-CDs directly as "functional monomer" for imprinting simplify the imprinting process and provide well recognition sites accessibility. The as-prepared M-MIPs@CDs sensor, using periodic mesoporous silica as imprinting matrix, and amino-CDs directly as "functional monomer", exhibited excellent selectivity and sensitivity toward TNT with detection limit of 17nM. The recycling process was sustainable for 10 times without obvious efficiency decrease. The feasibility of the developed method in real samples was successfully evaluated through the analysis of TNT in soil and water samples with satisfactory recoveries of 88.6-95.7%. The method proposed in this work was proved to be a convenient and practical way to prepare high sensitive and selective fluorescence MIPs@CDs sensors. Copyright © 2016 Elsevier B.V. All rights reserved.

Selection of process parameters for producing high quality defatted sesame flour at pilot scale.

PubMed

Manikantan, M R; Sharma, Rajiv; Yadav, D N; Gupta, R K

2015-03-01

The present work was undertaken to study the effect of pearling duration, soaking time, steaming duration and drying temperature on the quality of sesame seeds and mechanically extracted partially defatted sesame cake. On the basis of quality attributes i.e. high protein, low crude fibre, low residual oil and low oxalic acid, the optimum process parameters were selected. The combination of 20 min of pearling duration, 15 min of soaking, 15 min of steaming at 100 kPa pressure and drying at 50 °C yielded high quality partially defatted protein rich sesame flour as compared to untreated defatted sesame flour. The developed high quality partially defatted protein rich sesame flour may be used in various food applications as a vital ingredient to increase the nutritional significance of the prepared foodstuffs.

Landfill site selection using combination of GIS and fuzzy AHP, a case study: Iranshahr, Iran.

PubMed

Torabi-Kaveh, M; Babazadeh, R; Mohammadi, S D; Zaresefat, M

2016-03-09

One of the most important recent challenges in solid waste management throughout the world is site selection of sanitary landfill. Commonly, because of simultaneous effects of social, environmental, and technical parameters on suitability of a landfill site, landfill site selection is a complex process and depends on several criteria and regulations. This study develops a multi-criteria decision analysis (MCDA) process, which combines geographic information system (GIS) analysis with a fuzzy analytical hierarchy process (FAHP), to determine suitable sites for landfill construction in Iranshahr County, Iran. The GIS was used to calculate and classify selected criteria and FAHP was used to assess the criteria weights based on their effectiveness on selection of potential landfill sites. Finally, a suitability map was prepared by overlay analyses and suitable areas were identified. Four suitability classes within the study area were separated, including high, medium, low, and very low suitability areas, which represented 18%, 15%, 55%, and 12% of the study area, respectively. © The Author(s) 2016.

Genetic patterns of habitat fragmentation and past climate-change effects in the Mediterranean high-mountain plant Armeria caespitosa (Plumbaginaceae).

PubMed

García-Fernández, Alfredo; Iriondo, Jose M; Escudero, Adrián; Aguilar, Javier Fuertes; Feliner, Gonzalo Nieto

2013-08-01

Mountain plants are among the species most vulnerable to global warming, because of their isolation, narrow geographic distribution, and limited geographic range shifts. Stochastic and selective processes can act on the genome, modulating genetic structure and diversity. Fragmentation and historical processes also have a great influence on current genetic patterns, but the spatial and temporal contexts of these processes are poorly known. We aimed to evaluate the microevolutionary processes that may have taken place in Mediterranean high-mountain plants in response to changing historical environmental conditions. Genetic structure, diversity, and loci under selection were analyzed using AFLP markers in 17 populations distributed over the whole geographic range of Armeria caespitosa, an endemic plant that inhabits isolated mountains (Sierra de Guadarrama, Spain). Differences in altitude, geographic location, and climate conditions were considered in the analyses, because they may play an important role in selective and stochastic processes. Bayesian clustering approaches identified nine genetic groups, although some discrepancies in assignment were found between alternative analyses. Spatially explicit analyses showed a weak relationship between genetic parameters and spatial or environmental distances. However, a large proportion of outlier loci were detected, and some outliers were related to environmental variables. A. caespitosa populations exhibit spatial patterns of genetic structure that cannot be explained by the isolation-by-distance model. Shifts along the altitude gradient in response to Pleistocene climatic oscillations and environmentally mediated selective forces might explain the resulting structure and genetic diversity values found.

Evolution of resource cycling in ecosystems and individuals.

PubMed

Crombach, Anton; Hogeweg, Paulien

2009-06-01

Resource cycling is a defining process in the maintenance of the biosphere. Microbial communities, ranging from simple to highly diverse, play a crucial role in this process. Yet the evolutionary adaptation and speciation of micro-organisms have rarely been studied in the context of resource cycling. In this study, our basic questions are how does a community evolve its resource usage and how are resource cycles partitioned? We design a computational model in which a population of individuals evolves to take up nutrients and excrete waste. The waste of one individual is another's resource. Given a fixed amount of resources, this leads to resource cycles. We find that the shortest cycle dominates the ecological dynamics, and over evolutionary time its length is minimized. Initially a single lineage processes a long cycle of resources, later crossfeeding lineages arise. The evolutionary dynamics that follow are determined by the strength of indirect selection for resource cycling. We study indirect selection by changing the spatial setting and the strength of direct selection. If individuals are fixed at lattice sites or direct selection is low, indirect selection result in lineages that structure their local environment, leading to 'smart' individuals and stable patterns of resource dynamics. The individuals are good at cycling resources themselves and do this with a short cycle. On the other hand, if individuals randomly change position each time step, or direct selection is high, individuals are more prone to crossfeeding: an ecosystem based solution with turbulent resource dynamics, and individuals that are less capable of cycling resources themselves. In a baseline model of ecosystem evolution we demonstrate different eco-evolutionary trajectories of resource cycling. By varying the strength of indirect selection through the spatial setting and direct selection, the integration of information by the evolutionary process leads to qualitatively different results from individual smartness to cooperative community structures.

Innovative Approach for High Strength, High Thermal Conductive Composite Materials: Data Base

DTIC Science & Technology

2013-11-01

pitch fiber types, from which we were able to down select K6356U pitch fiber with balanced TC and strength properties. A prepreg processing line was...Creating a robust prepreg processing line to infuse unidirectional pitch fiber tape that can be used with other fibers…Pan-based carbon or glass...pitch fiber composites • Compression molding process outperforms autoclaving in mechanical and thermal properties using the same prepreg material and

Multivariate fault isolation of batch processes via variable selection in partial least squares discriminant analysis.

PubMed

Yan, Zhengbing; Kuang, Te-Hui; Yao, Yuan

2017-09-01

In recent years, multivariate statistical monitoring of batch processes has become a popular research topic, wherein multivariate fault isolation is an important step aiming at the identification of the faulty variables contributing most to the detected process abnormality. Although contribution plots have been commonly used in statistical fault isolation, such methods suffer from the smearing effect between correlated variables. In particular, in batch process monitoring, the high autocorrelations and cross-correlations that exist in variable trajectories make the smearing effect unavoidable. To address such a problem, a variable selection-based fault isolation method is proposed in this research, which transforms the fault isolation problem into a variable selection problem in partial least squares discriminant analysis and solves it by calculating a sparse partial least squares model. As different from the traditional methods, the proposed method emphasizes the relative importance of each process variable. Such information may help process engineers in conducting root-cause diagnosis. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dafler, J.R.; Sinnott, J.; Novil, M.

The first phase of a study to identify candidate processes and products suitable for future exploitation using high-temperature solar energy is presented. This phase has been principally analytical, consisting of techno-economic studies, thermodynamic assessments of chemical reactions and processes, and the determination of market potentials for major chemical commodities that use significant amounts of fossil resources today. The objective was to identify energy-intensive processes that would be suitable for the production of chemicals and fuels using solar energy process heat. Of particular importance was the comparison of relative costs and energy requirements for the selected solar product versus costs formore » the product derived from conventional processing. The assessment methodology used a systems analytical approach to identify processes and products having the greatest potential for solar energy-thermal processing. This approach was used to establish the basis for work to be carried out in subsequent phases of development. It has been the intent of the program to divide the analysis and process identification into the following three distinct areas: (1) process selection, (2) process evaluation, and (3) ranking of processes. Four conventional processes were selected for assessment namely, methanol synthesis, styrene monomer production, vinyl chloride monomer production, and terephthalic acid production.« less

Hybrid feature selection for supporting lightweight intrusion detection systems

NASA Astrophysics Data System (ADS)

Song, Jianglong; Zhao, Wentao; Liu, Qiang; Wang, Xin

2017-08-01

Redundant and irrelevant features not only cause high resource consumption but also degrade the performance of Intrusion Detection Systems (IDS), especially when coping with big data. These features slow down the process of training and testing in network traffic classification. Therefore, a hybrid feature selection approach in combination with wrapper and filter selection is designed in this paper to build a lightweight intrusion detection system. Two main phases are involved in this method. The first phase conducts a preliminary search for an optimal subset of features, in which the chi-square feature selection is utilized. The selected set of features from the previous phase is further refined in the second phase in a wrapper manner, in which the Random Forest(RF) is used to guide the selection process and retain an optimized set of features. After that, we build an RF-based detection model and make a fair comparison with other approaches. The experimental results on NSL-KDD datasets show that our approach results are in higher detection accuracy as well as faster training and testing processes.

Getting to the point: Rapid point selection and variable density InSAR time series for urban deformation monitoring

NASA Astrophysics Data System (ADS)

Spaans, K.; Hooper, A. J.

2017-12-01

The short revisit time and high data acquisition rates of current satellites have resulted in increased interest in the development of deformation monitoring and rapid disaster response capability, using InSAR. Fast, efficient data processing methodologies are required to deliver the timely results necessary for this, and also to limit computing resources required to process the large quantities of data being acquired. Contrary to volcano or earthquake applications, urban monitoring requires high resolution processing, in order to differentiate movements between buildings, or between buildings and the surrounding land. Here we present Rapid time series InSAR (RapidSAR), a method that can efficiently update high resolution time series of interferograms, and demonstrate its effectiveness over urban areas. The RapidSAR method estimates the coherence of pixels on an interferogram-by-interferogram basis. This allows for rapid ingestion of newly acquired images without the need to reprocess the earlier acquired part of the time series. The coherence estimate is based on ensembles of neighbouring pixels with similar amplitude behaviour through time, which are identified on an initial set of interferograms, and need be re-evaluated only occasionally. By taking into account scattering properties of points during coherence estimation, a high quality coherence estimate is achieved, allowing point selection at full resolution. The individual point selection maximizes the amount of information that can be extracted from each interferogram, as no selection compromise has to be reached between high and low coherence interferograms. In other words, points do not have to be coherent throughout the time series to contribute to the deformation time series. We demonstrate the effectiveness of our method over urban areas in the UK. We show how the algorithm successfully extracts high density time series from full resolution Sentinel-1 interferograms, and distinguish clearly between buildings and surrounding vegetation or streets. The fact that new interferograms can be processed separately from the remainder of the time series helps manage the high data volumes, both in space and time, generated by current missions.

A non-volatile flip-flop based on diode-selected PCM for ultra-low power systems

NASA Astrophysics Data System (ADS)

Ye, Yong; Du, Yuan; Gao, Dan; Kang, Yong; Song, Zhitang; Chen, Bomy

2016-10-01

As the process technology is continuously shrinking, low power consumption is a major issue in VLSI Systems-on-Chip (SoCs), especially for standby-power-critical applications. Recently, the emerging CMOS-compatible non-volatile memories (NVMs), such as Phase Change Memory (PCM), have been used as on-chip storage elements, which can obtain non-volatile processing, nearly-zero standby power and instant-on capability. PCM has been considered as the best candidate for the next generation of NVMs for its low cost, high density and high resistance transformation ratio. In this paper, for the first time, we present a diode-selected PCM based non-volatile flip-flop (NVFF) which is optimized for better power consumption and process variation tolerance. With dual trench isolation process, the diode-selected PCM realizes ultra small area, which is very suitable for multi-context configuration and large scale flip-flops matrix. Since the MOS-selected PCM is hard to shrink further due to large amount of PCM write current, the proposed NVFF achieves higher power efficiency without loss of current driving capability. Using the 40nm manufacturing process, the area of the cell (1D1R) is as small as 0.016 μm2. Simulation results show that the energy consumption during the recall operation is 62 fJ with 1.1 standard supply voltage, which is reduced by 54.9% compared to the previous 2T2R based NVFF. When the supply voltage reduces to 0.7 V, the recall energy is as low as 17 fJ. With the great advantages in cell size and energy, the proposed diode-selected NVFF is very applicable and cost-effective for ULP systems.

Characterization of the Fe-Co-1.5V soft ferromagnetic alloy processed by Laser Engineered Net Shaping (LENS)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kustas, Andrew B.; Susan, Donald F.; Johnson, Kyle L.

Processing of the low workability Fe-Co-1.5V (Hiperco® equivalent) alloy is demonstrated using the Laser Engineered Net Shaping (LENS) metals additive manufacturing technique. As an innovative and highly localized solidification process, LENS is shown to overcome workability issues that arise during conventional thermomechanical processing, enabling the production of bulk, near net-shape forms of the Fe-Co alloy. Bulk LENS structures appeared to be ductile with no significant macroscopic defects. Atomic ordering was evaluated and significantly reduced in as-built LENS specimens relative to an annealed condition, tailorable through selection of processing parameters. Fine equiaxed grain structures were observed in as-built specimens following solidification,more » which then evolved toward a highly heterogeneous bimodal grain structure after annealing. The microstructure evolution in Fe-Co is discussed in the context of classical solidification theory and selective grain boundary pinning processes. In conclusion, magnetic properties were also assessed and shown to fall within the extremes of conventionally processed Hiperco® alloys.« less

Characterization of the Fe-Co-1.5V soft ferromagnetic alloy processed by Laser Engineered Net Shaping (LENS)

DOE PAGES

Kustas, Andrew B.; Susan, Donald F.; Johnson, Kyle L.; ...

2018-02-21

Processing of the low workability Fe-Co-1.5V (Hiperco® equivalent) alloy is demonstrated using the Laser Engineered Net Shaping (LENS) metals additive manufacturing technique. As an innovative and highly localized solidification process, LENS is shown to overcome workability issues that arise during conventional thermomechanical processing, enabling the production of bulk, near net-shape forms of the Fe-Co alloy. Bulk LENS structures appeared to be ductile with no significant macroscopic defects. Atomic ordering was evaluated and significantly reduced in as-built LENS specimens relative to an annealed condition, tailorable through selection of processing parameters. Fine equiaxed grain structures were observed in as-built specimens following solidification,more » which then evolved toward a highly heterogeneous bimodal grain structure after annealing. The microstructure evolution in Fe-Co is discussed in the context of classical solidification theory and selective grain boundary pinning processes. In conclusion, magnetic properties were also assessed and shown to fall within the extremes of conventionally processed Hiperco® alloys.« less

High throughput screening of ligand binding to macromolecules using high resolution powder diffraction

DOEpatents

Von Dreele, Robert B.; D'Amico, Kevin

2006-10-31

A process is provided for the high throughput screening of binding of ligands to macromolecules using high resolution powder diffraction data including producing a first sample slurry of a selected polycrystalline macromolecule material and a solvent, producing a second sample slurry of a selected polycrystalline macromolecule material, one or more ligands and the solvent, obtaining a high resolution powder diffraction pattern on each of said first sample slurry and the second sample slurry, and, comparing the high resolution powder diffraction pattern of the first sample slurry and the high resolution powder diffraction pattern of the second sample slurry whereby a difference in the high resolution powder diffraction patterns of the first sample slurry and the second sample slurry provides a positive indication for the formation of a complex between the selected polycrystalline macromolecule material and at least one of the one or more ligands.

Evaluation of Roadway Reallocation Projects: Analysis of Before-and-After Travel Speeds and Congestion Utilizing High-Resolution Bus Transit Data

DOT National Transportation Integrated Search

2017-11-01

The traditional process of identifying corridors for road diet improvements involves selecting potential corridors (mostly based on identifying fourlane roads) and conducting a traffic impact analysis of proposed changes on a selected roadway before ...

Anisotropic diamond etching through thermochemical reaction between Ni and diamond in high-temperature water vapour.

PubMed

Nagai, Masatsugu; Nakanishi, Kazuhiro; Takahashi, Hiraku; Kato, Hiromitsu; Makino, Toshiharu; Yamasaki, Satoshi; Matsumoto, Tsubasa; Inokuma, Takao; Tokuda, Norio

2018-04-27

Diamond possesses excellent physical and electronic properties, and thus various applications that use diamond are under development. Additionally, the control of diamond geometry by etching technique is essential for such applications. However, conventional wet processes used for etching other materials are ineffective for diamond. Moreover, plasma processes currently employed for diamond etching are not selective, and plasma-induced damage to diamond deteriorates the device-performances. Here, we report a non-plasma etching process for single crystal diamond using thermochemical reaction between Ni and diamond in high-temperature water vapour. Diamond under Ni films was selectively etched, with no etching at other locations. A diamond-etching rate of approximately 8.7 μm/min (1000 °C) was successfully achieved. To the best of our knowledge, this rate is considerably greater than those reported so far for other diamond-etching processes, including plasma processes. The anisotropy observed for this diamond etching was considerably similar to that observed for Si etching using KOH.

Processing on high efficiency solar collector coatings

NASA Technical Reports Server (NTRS)

Roberts, M.

1977-01-01

Wavelength selective coatings for solar collectors are considered. Substrates with good infrared reflectivity were examined along with their susceptibility to physical and environmental damage. Improvements of reflective surfaces were accomplished through buffing, chemical polishing and other surface processing methods.

Data Processing at the High School Level.

ERIC Educational Resources Information Center

Richmond, Sue

1981-01-01

The teaching of data processing in the secondary school is examined, including teachers (certification, work experience), textbooks (selection, concentration), community (advisory committees, career exploration), students (recruitment, aptitude tests), instruction methods (simulation, audiovisuals, field trips), course content (machine technology,…

Reward speeds up and increases consistency of visual selective attention: a lifespan comparison.

PubMed

Störmer, Viola; Eppinger, Ben; Li, Shu-Chen

2014-06-01

Children and older adults often show less favorable reward-based learning and decision making, relative to younger adults. It is unknown, however, whether reward-based processes that influence relatively early perceptual and attentional processes show similar lifespan differences. In this study, we investigated whether stimulus-reward associations affect selective visual attention differently across the human lifespan. Children, adolescents, younger adults, and older adults performed a visual search task in which the target colors were associated with either high or low monetary rewards. We discovered that high reward value speeded up response times across all four age groups, indicating that reward modulates attentional selection across the lifespan. This speed-up in response time was largest in younger adults, relative to the other three age groups. Furthermore, only younger adults benefited from high reward value in increasing response consistency (i.e., reduction of trial-by-trial reaction time variability). Our findings suggest that reward-based modulations of relatively early and implicit perceptual and attentional processes are operative across the lifespan, and the effects appear to be greater in adulthood. The age-specific effect of reward on reducing intraindividual response variability in younger adults likely reflects mechanisms underlying the development and aging of reward processing, such as lifespan age differences in the efficacy of dopaminergic modulation. Overall, the present results indicate that reward shapes visual perception across different age groups by biasing attention to motivationally salient events.

Patient's decision making in selecting a hospital for elective orthopaedic surgery.

PubMed

Moser, Albine; Korstjens, Irene; van der Weijden, Trudy; Tange, Huibert

2010-12-01

The admission to a hospital for elective surgery, like arthroplasty, can be planned ahead. The elective nature of arthroplasty and the increasing stimulus of the public to critically select a hospital raise the issue of how patients actually take such decisions. The aim of this paper is to describe the decision-making process of selecting a hospital as experienced by people who underwent elective joint arthroplasty and to understand what factors influenced the decision-making process. Qualitative descriptive study with 18 participants who had a hip or knee replacement within the last 5 years. Data were gathered from eight individual interviews and four focus group interviews and analysed by content analysis. Three categories that influenced the selection of a hospital were revealed: information sources, criteria in decision making and decision-making styles within the GP- patient relationship. Various contextual aspects influenced the decision-making process. Most participants gave higher priority to the selection of a medical specialist than to the selection of a hospital. Selecting a hospital for arthroplasty is extremely complex. The decision-making process is a highly individualized process because patients have to consider and assimilate a diversity of aspects, which are relevant to their specific situation. Our findings support the model of shared decision making, which indicates that general practitioners should be attuned to the distinct needs of each patient at various moments during the decision making, taking into account personal, medical and contextual factors. © 2010 Blackwell Publishing Ltd.

Evolution of Near-Surface Internal and External Oxide Morphology During High-Temperature Selective Oxidation of Steels

NASA Astrophysics Data System (ADS)

Story, Mary E.; Webler, Bryan A.

2018-05-01

In this work we examine some observations made using high-temperature confocal scanning laser microscopy (HT-CSLM) during selective oxidation experiments. A plain carbon steel and advanced high-strength steel (AHSS) were selectively oxidized at high temperature (850-900°C) in either low oxygen or water vapor atmospheres. Surface evolution, including thermal grooving along grain boundaries and oxide growth, was viewed in situ during heating. Experiments investigated the influence of the microstructure and oxidizing atmosphere on selective oxidation behavior. Sequences of CSLM still frames collected during the experiment were processed with ImageJ to obtain histograms that showed a general darkening trend indicative of oxidation over time with all samples. Additional ex situ scanning electron microscopy and energy dispersive spectroscopy analysis supported in situ observations. Distinct oxidation behavior was observed for each case. Segregation, grain orientation, and extent of internal oxidation were all found to strongly influence surface evolution.

A proposed framework on hybrid feature selection techniques for handling high dimensional educational data

NASA Astrophysics Data System (ADS)

Shahiri, Amirah Mohamed; Husain, Wahidah; Rashid, Nur'Aini Abd

2017-10-01

Huge amounts of data in educational datasets may cause the problem in producing quality data. Recently, data mining approach are increasingly used by educational data mining researchers for analyzing the data patterns. However, many research studies have concentrated on selecting suitable learning algorithms instead of performing feature selection process. As a result, these data has problem with computational complexity and spend longer computational time for classification. The main objective of this research is to provide an overview of feature selection techniques that have been used to analyze the most significant features. Then, this research will propose a framework to improve the quality of students' dataset. The proposed framework uses filter and wrapper based technique to support prediction process in future study.

Exploiting Process-Related Advantages of Selective Laser Melting for the Production of High-Manganese Steel.

PubMed

Haase, Christian; Bültmann, Jan; Hof, Jan; Ziegler, Stephan; Bremen, Sebastian; Hinke, Christian; Schwedt, Alexander; Prahl, Ulrich; Bleck, Wolfgang

2017-01-11

Metal additive manufacturing has strongly gained scientific and industrial importance during the last decades due to the geometrical flexibility and increased reliability of parts, as well as reduced equipment costs. Within the field of metal additive manufacturing methods, selective laser melting (SLM) is an eligible technique for the production of fully dense bulk material with complex geometry. In the current study, we addressed the application of SLM for processing a high-manganese TRansformation-/TWinning-Induced Plasticity (TRIP/TWIP) steel. The solidification behavior was analyzed by careful characterization of the as-built microstructure and element distribution using optical and scanning electron microscopy (SEM). In addition, the deformation behavior was studied using uniaxial tensile testing and SEM. Comparison with conventionally produced TRIP/TWIP steel revealed that elemental segregation, which is normally very pronounced in high-manganese steels and requires energy-intensive post processing, is reduced due to the high cooling rates during SLM. Also, the very fast cooling promoted ε- and α'-martensite formation prior to deformation. The superior strength and pronounced anisotropy of the SLM-produced material was correlated with the microstructure based on the process-specific characteristics.

Exploiting Process-Related Advantages of Selective Laser Melting for the Production of High-Manganese Steel

PubMed Central

Haase, Christian; Bültmann, Jan; Hof, Jan; Ziegler, Stephan; Bremen, Sebastian; Hinke, Christian; Schwedt, Alexander; Prahl, Ulrich; Bleck, Wolfgang

2017-01-01

Metal additive manufacturing has strongly gained scientific and industrial importance during the last decades due to the geometrical flexibility and increased reliability of parts, as well as reduced equipment costs. Within the field of metal additive manufacturing methods, selective laser melting (SLM) is an eligible technique for the production of fully dense bulk material with complex geometry. In the current study, we addressed the application of SLM for processing a high-manganese TRansformation-/TWinning-Induced Plasticity (TRIP/TWIP) steel. The solidification behavior was analyzed by careful characterization of the as-built microstructure and element distribution using optical and scanning electron microscopy (SEM). In addition, the deformation behavior was studied using uniaxial tensile testing and SEM. Comparison with conventionally produced TRIP/TWIP steel revealed that elemental segregation, which is normally very pronounced in high-manganese steels and requires energy-intensive post processing, is reduced due to the high cooling rates during SLM. Also, the very fast cooling promoted ε- and α’-martensite formation prior to deformation. The superior strength and pronounced anisotropy of the SLM-produced material was correlated with the microstructure based on the process-specific characteristics. PMID:28772416

Selective and Catalyst-free Oxidation of D-Glucose to D-Glucuronic acid induced by High-Frequency Ultrasound

PubMed Central

Amaniampong, Prince N.; Karam, Ayman; Trinh, Quang Thang; Xu, Kai; Hirao, Hajime; Jérôme, François; Chatel, Gregory

2017-01-01

This systematic experimental investigation reveals that high-frequency ultrasound irradiation (550 kHz) induced oxidation of D-glucose to glucuronic acid in excellent yield without assistance of any (bio)catalyst. Oxidation is induced thanks to the in situ production of radical species in water. Experiments show that the dissolved gases play an important role in governing the nature of generated radical species and thus the selectivity for glucuronic acid. Importantly, this process yields glucuronic acid instead of glucuronate salt typically obtained via conventional (bio)catalyst routes, which is of huge interest in respect of downstream processing. Investigations using disaccharides revealed that radicals generated by high frequency ultrasound were also capable of promoting tandem hydrolysis/oxidation reactions. PMID:28084448

Event-related potentials during visual selective attention in children of alcoholics.

PubMed

van der Stelt, O; Gunning, W B; Snel, J; Kok, A

1998-12-01

Event-related potentials were recorded from 7- to 18-year-old children of alcoholics (COAs, n = 50) and age- and sex-matched control children (n = 50) while they performed a visual selective attention task. The task was to attend selectively to stimuli with a specified color (red or blue) in an attempt to detect the occurrence of target stimuli. COAs manifested a smaller P3b amplitude to attended-target stimuli over the parietal and occipital scalp than did the controls. A more specific analysis indicated that both the attentional relevance and the target properties of the eliciting stimulus determined the observed P3b amplitude differences between COAs and controls. In contrast, no significant group differences were observed in attention-related earlier occurring event-related potential components, referred to as frontal selection positivity, selection negativity, and N2b. These results represent neurophysiological evidence that COAs suffer from deficits at a late (semantic) level of visual selective information processing that are unlikely a consequence of deficits at earlier (sensory) levels of selective processing. The findings support the notion that a reduced visual P3b amplitude in COAs represents a high-level processing dysfunction indicating their increased vulnerability to alcoholism.

High-performance multilayer composite membranes with mussel-inspired polydopamine as a versatile molecular bridge for CO2 separation.

PubMed

Li, Panyuan; Wang, Zhi; Li, Wen; Liu, Yanni; Wang, Jixiao; Wang, Shichang

2015-07-22

It is desirable to develop high-performance composite membranes for efficient CO2 separation in CO2 capture process. Introduction of a highly permeable polydimethylsiloxane (PDMS) intermediate layer between a selective layer and a porous support has been considered as a simple but efficient way to enhance gas permeance while maintaining high gas selectivity, because the introduced intermediate layer could benefit the formation of an ultrathin defect-free selective layer owing to the circumvention of pore penetration phenomenon. However, the selection of selective layer materials is unfavorably restricted because of the low surface energy of PDMS. Various highly hydrophilic membrane materials such as amino group-rich polyvinylamine (PVAm), a representative facilitated transport membrane material for CO2 separation, could not be facilely coated over the surface of the hydrophobic PDMS intermediate layer uniformly. Inspired by the hydrophilic nature and strong adhesive ability of polydopamine (PDA), PDA was therefore selected as a versatile molecular bridge between hydrophobic PDMS and hydrophilic PVAm. The PDA coating endows a highly compatible interface between both components with a large surface energy difference via multiple-site cooperative interactions. The resulting multilayer composite membrane with a thin facilitated transport PVAm selective layer exhibits a notably enhanced CO2 permeance (1887 GPU) combined with a slightly improved CO2/N2 selectivity (83), as well as superior structural stability. Similarly, the multilayer composite membrane with a hydrophilic CO2-philic Pebax 1657 selective layer was also developed for enhanced CO2 separation performance.

OM300 Direction Drilling Module

DOE Data Explorer

MacGugan, Doug

2013-08-22

OM300 – Geothermal Direction Drilling Navigation Tool: Design and produce a prototype directional drilling navigation tool capable of high temperature operation in geothermal drilling Accuracies of 0.1° Inclination and Tool Face, 0.5° Azimuth Environmental Ruggedness typical of existing oil/gas drilling Multiple Selectable Sensor Ranges High accuracy for navigation, low bandwidth High G-range & bandwidth for Stick-Slip and Chirp detection Selectable serial data communications Reduce cost of drilling in high temperature Geothermal reservoirs Innovative aspects of project Honeywell MEMS* Vibrating Beam Accelerometers (VBA) APS Flux-gate Magnetometers Honeywell Silicon-On-Insulator (SOI) High-temperature electronics Rugged High-temperature capable package and assembly process

State recovery and lockstep execution restart in a system with multiprocessor pairing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gara, Alan; Gschwind, Michael K; Salapura, Valentina

System, method and computer program product for a multiprocessing system to offer selective pairing of processor cores for increased processing reliability. A selective pairing facility is provided that selectively connects, i.e., pairs, multiple microprocessor or processor cores to provide one highly reliable thread (or thread group). Each paired microprocessor or processor cores that provide one highly reliable thread for high-reliability connect with a system components such as a memory "nest" (or memory hierarchy), an optional system controller, and optional interrupt controller, optional I/O or peripheral devices, etc. The memory nest is attached to a selective pairing facility via a switchmore » or a bus. Each selectively paired processor core is includes a transactional execution facility, whereing the system is configured to enable processor rollback to a previous state and reinitialize lockstep execution in order to recover from an incorrect execution when an incorrect execution has been detected by the selective pairing facility.« less

Selection Interviews of Students for Master's Programs in Counseling: An Exploratory Study.

ERIC Educational Resources Information Center

Nagpal, Smita; Ritchie, Martin H.

2002-01-01

Counselor education faculty were interviewed regarding the evaluation criteria and decision-making processes used during selection interviews. Ten characteristics were identified that participants looked for during interviews. There was a high degree of agreement among participants on the evaluation criteria they used. However, the same…

Genetic algorithm based input selection for a neural network function approximator with applications to SSME health monitoring

NASA Technical Reports Server (NTRS)

Peck, Charles C.; Dhawan, Atam P.; Meyer, Claudia M.

1991-01-01

A genetic algorithm is used to select the inputs to a neural network function approximator. In the application considered, modeling critical parameters of the space shuttle main engine (SSME), the functional relationship between measured parameters is unknown and complex. Furthermore, the number of possible input parameters is quite large. Many approaches have been used for input selection, but they are either subjective or do not consider the complex multivariate relationships between parameters. Due to the optimization and space searching capabilities of genetic algorithms they were employed to systematize the input selection process. The results suggest that the genetic algorithm can generate parameter lists of high quality without the explicit use of problem domain knowledge. Suggestions for improving the performance of the input selection process are also provided.

Hit to lead account of the discovery of bisbenzamide and related ureidobenzamide inhibitors of Rho kinase.

PubMed

Morwick, Tina; Büttner, Frank H; Cywin, Charles L; Dahmann, Georg; Hickey, Eugene; Jakes, Scott; Kaplita, Paul; Kashem, Mohammed A; Kerr, Steven; Kugler, Stanley; Mao, Wang; Marshall, Daniel; Paw, Zofia; Shih, Cheng-Kon; Wu, Frank; Young, Erick

2010-01-28

A highly selective series of bisbenzamide inhibitors of Rho-associated coiled-coil forming protein kinase (ROCK) and a related ureidobenzamide series, both identified by high throughput screening (HTS), are described. Details of the hit validation and lead generation process, including structure-activity relationship (SAR) studies, a selectivity assessment, target-independent profiling (TIP) results, and an analysis of functional activity using a rat aortic ring assay are discussed.

Additive manufacturing of metals: a brief review of the characteristic microstructures and properties of steels, Ti-6Al-4V and high-entropy alloys

PubMed Central

Gorsse, Stéphane; Hutchinson, Christopher; Gouné, Mohamed; Banerjee, Rajarshi

2017-01-01

Abstract We present a brief review of the microstructures and mechanical properties of selected metallic alloys processed by additive manufacturing (AM). Three different alloys, covering a large range of technology readiness levels, are selected to illustrate particular microstructural features developed by AM and clarify the engineering paradigm relating process–microstructure–property. With Ti-6Al-4V the emphasis is placed on the formation of metallurgical defects and microstructures induced by AM and their role on mechanical properties. The effects of the large in-built dislocation density, surface roughness and build atmosphere on mechanical and damage properties are discussed using steels. The impact of rapid solidification inherent to AM on phase selection is highlighted for high-entropy alloys. Using property maps, published mechanical properties of additive manufactured alloys are graphically summarized and compared to conventionally processed counterparts. PMID:28970868

Automated high throughput microscale antibody purification workflows for accelerating antibody discovery

PubMed Central

Luan, Peng; Lee, Sophia; Paluch, Maciej; Kansopon, Joe; Viajar, Sharon; Begum, Zahira; Chiang, Nancy; Nakamura, Gerald; Hass, Philip E.; Wong, Athena W.; Lazar, Greg A.

2018-01-01

ABSTRACT To rapidly find “best-in-class” antibody therapeutics, it has become essential to develop high throughput (HTP) processes that allow rapid assessment of antibodies for functional and molecular properties. Consequently, it is critical to have access to sufficient amounts of high quality antibody, to carry out accurate and quantitative characterization. We have developed automated workflows using liquid handling systems to conduct affinity-based purification either in batch or tip column mode. Here, we demonstrate the capability to purify >2000 antibodies per day from microscale (1 mL) cultures. Our optimized, automated process for human IgG1 purification using MabSelect SuRe resin achieves ∼70% recovery over a wide range of antibody loads, up to 500 µg. This HTP process works well for hybridoma-derived antibodies that can be purified by MabSelect SuRe resin. For rat IgG2a, which is often encountered in hybridoma cultures and is challenging to purify via an HTP process, we established automated purification with GammaBind Plus resin. Using these HTP purification processes, we can efficiently recover sufficient amounts of antibodies from mammalian transient or hybridoma cultures with quality comparable to conventional column purification. PMID:29494273

Human genomic regions with exceptionally high levels of population differentiation identified from 911 whole-genome sequences.

PubMed

Colonna, Vincenza; Ayub, Qasim; Chen, Yuan; Pagani, Luca; Luisi, Pierre; Pybus, Marc; Garrison, Erik; Xue, Yali; Tyler-Smith, Chris; Abecasis, Goncalo R; Auton, Adam; Brooks, Lisa D; DePristo, Mark A; Durbin, Richard M; Handsaker, Robert E; Kang, Hyun Min; Marth, Gabor T; McVean, Gil A

2014-06-30

Population differentiation has proved to be effective for identifying loci under geographically localized positive selection, and has the potential to identify loci subject to balancing selection. We have previously investigated the pattern of genetic differentiation among human populations at 36.8 million genomic variants to identify sites in the genome showing high frequency differences. Here, we extend this dataset to include additional variants, survey sites with low levels of differentiation, and evaluate the extent to which highly differentiated sites are likely to result from selective or other processes. We demonstrate that while sites with low differentiation represent sampling effects rather than balancing selection, sites showing extremely high population differentiation are enriched for positive selection events and that one half may be the result of classic selective sweeps. Among these, we rediscover known examples, where we actually identify the established functional SNP, and discover novel examples including the genes ABCA12, CALD1 and ZNF804, which we speculate may be linked to adaptations in skin, calcium metabolism and defense, respectively. We identify known and many novel candidate regions for geographically restricted positive selection, and suggest several directions for further research.

Estimating and mapping ecological processes influencing microbial community assembly

PubMed Central

Stegen, James C.; Lin, Xueju; Fredrickson, Jim K.; Konopka, Allan E.

2015-01-01

Ecological community assembly is governed by a combination of (i) selection resulting from among-taxa differences in performance; (ii) dispersal resulting from organismal movement; and (iii) ecological drift resulting from stochastic changes in population sizes. The relative importance and nature of these processes can vary across environments. Selection can be homogeneous or variable, and while dispersal is a rate, we conceptualize extreme dispersal rates as two categories; dispersal limitation results from limited exchange of organisms among communities, and homogenizing dispersal results from high levels of organism exchange. To estimate the influence and spatial variation of each process we extend a recently developed statistical framework, use a simulation model to evaluate the accuracy of the extended framework, and use the framework to examine subsurface microbial communities over two geologic formations. For each subsurface community we estimate the degree to which it is influenced by homogeneous selection, variable selection, dispersal limitation, and homogenizing dispersal. Our analyses revealed that the relative influences of these ecological processes vary substantially across communities even within a geologic formation. We further identify environmental and spatial features associated with each ecological process, which allowed mapping of spatial variation in ecological-process-influences. The resulting maps provide a new lens through which ecological systems can be understood; in the subsurface system investigated here they revealed that the influence of variable selection was associated with the rate at which redox conditions change with subsurface depth. PMID:25983725

Selective interference reveals dissociation between memory for location and colour.

PubMed

Vuontela, V; Rämä, P; Raninen, A; Aronen, H J; Carlson, S

1999-08-02

The aim was to study whether there is indication of a dissociation in processing of visuospatial and colour information in working memory in humans. Experimental subjects performed visuospatial and colour n-back tasks with and without visuospatial and colour distractive stimuli presented in the middle of the delay period to specifically affect mnemonic processing of task-related information. In the high memory-load condition, the visuospatial, but not the colour, task was selectively disrupted by visuospatial but not colour distractors. When subvocal rehearsal of the memoranda in the colour task was prevented by articulatory suppression; colour task performance was also selectively disrupted by distractors qualitatively similar to the memoranda. The results support the suggestion that visual working memory for location is processed separate from that for colour.

Age-related decline in bottom-up processing and selective attention in the very old.

PubMed

Zhuravleva, Tatyana Y; Alperin, Brittany R; Haring, Anna E; Rentz, Dorene M; Holcomb, Philip J; Daffner, Kirk R

2014-06-01

Previous research demonstrating age-related deficits in selective attention have not included old-old adults, an increasingly important group to study. The current investigation compared event-related potentials in 15 young-old (65-79 years old) and 23 old-old (80-99 years old) subjects during a color-selective attention task. Subjects responded to target letters in a specified color (Attend) while ignoring letters in a different color (Ignore) under both low and high loads. There were no group differences in visual acuity, accuracy, reaction time, or latency of early event-related potential components. The old-old group showed a disruption in bottom-up processing, indexed by a substantially diminished posterior N1 (smaller amplitude). They also demonstrated markedly decreased modulation of bottom-up processing based on selected visual features, indexed by the posterior selection negativity (SN), with similar attenuation under both loads. In contrast, there were no group differences in frontally mediated attentional selection, measured by the anterior selection positivity (SP). There was a robust inverse relationship between the size of the SN and SP (the smaller the SN, the larger the SP), which may represent an anteriorly supported compensatory mechanism. In the absence of a decline in top-down modulation indexed by the SP, the diminished SN may reflect age-related degradation of early bottom-up visual processing in old-old adults.

Fibrous selective emitter structures from sol-gel process

NASA Astrophysics Data System (ADS)

Chen, K. C.

1999-03-01

Selective emitters have the potential benefit of high efficiency due to the matching of emission spectra to the response of photovoltaic (PV) cells. Continuous uniform rare-earth oxide selective emitter fibers were successfully fabricated using a viscous solution made from metal organic precursors. Cylindrical- and planar configuration emitter structures were made by direct cross-winding or stacking of precursor fiber layers. The combustion and optical performance of the planar emitter structures were tested. The results indicates that both the designing of the fiber packing density and the thickness is critical for high photon and power output.

Method for construction of bacterial strains with increased succinic acid production

DOEpatents

Donnelly, Mark I.; Sanville-Millard, Cynthia; Chatterjee, Ranjini

2000-01-01

A fermentation process for producing succinic acid is provided comprising selecting a bacterial strain that does not produce succinic acid in high yield, disrupting the normal regulation of sugar metabolism of said bacterial strain, and combining the mutant bacterial strain and selected sugar in anaerobic conditions to facilitate production of succinic acid. Also provided is a method for changing low yield succinic acid producing bacteria to high yield succinic acid producing bacteria comprising selecting a bacterial strain having a phosphotransferase system and altering the phosphotransferase system so as to allow the bacterial strain to simultaneously metabolize different sugars.

Effects of selected pectinolytic bacterial strains on water-retting of hemp and fibre properties.

PubMed

Di Candilo, M; Bonatti, P M; Guidetti, C; Focher, B; Grippo, C; Tamburini, E; Mastromei, G

2010-01-01

To study the effect of selected bacterial strains on hemp water-retting and properties of retted fibre. The trials were performed in laboratory tanks. The traditional water-retting process, without inoculum addition, was compared to a process modified by inoculating water tanks with two selected pectinolytic bacteria: the anaerobic strain Clostridium sp. L1/6 and the aerobic strain Bacillus sp. ROO40B. Six different incubation times were compared. Half the fibre obtained from each tank was combed. Micromorphological analyses were performed by scanning electron microscopy on uncombed and combed fibres. Moreover, organoleptic and chemical analyses of uncombed fibres were performed. The inoculum, besides speeding up the process, significantly improved the fibre quality. The fibre was not damaged by mechanical hackling, thanks to the good retting level obtained by the addition of selected strains, differently to what happened with the traditionally retted fibre. The best fibre quality was obtained after 3-4 days of retting with the addition of the bacterial inoculum. Retting is the major limitation to an efficient production of high-quality hemp fibres. The water-retting process and fibre quality were substantially improved by simultaneously inoculating water tanks with two selected pectinolytic strains.

Tomography and Purification of the Temporal-Mode Structure of Quantum Light

NASA Astrophysics Data System (ADS)

Ansari, Vahid; Donohue, John M.; Allgaier, Markus; Sansoni, Linda; Brecht, Benjamin; Roslund, Jonathan; Treps, Nicolas; Harder, Georg; Silberhorn, Christine

2018-05-01

High-dimensional quantum information processing promises capabilities beyond the current state of the art, but addressing individual information-carrying modes presents a significant experimental challenge. Here we demonstrate effective high-dimensional operations in the time-frequency domain of nonclassical light. We generate heralded photons with tailored temporal-mode structures through the pulse shaping of a broadband parametric down-conversion pump. We then implement a quantum pulse gate, enabled by dispersion-engineered sum-frequency generation, to project onto programmable temporal modes, reconstructing the quantum state in seven dimensions. We also manipulate the time-frequency structure by selectively removing temporal modes, explicitly demonstrating the effectiveness of engineered nonlinear processes for the mode-selective manipulation of quantum states.

Selective sweep mapping of genes with large phenotypic effects.

PubMed

Pollinger, John P; Bustamante, Carlos D; Fledel-Alon, Adi; Schmutz, Sheila; Gray, Melissa M; Wayne, Robert K

2005-12-01

Many domestic dog breeds have originated through fixation of discrete mutations by intense artificial selection. As a result of this process, markers in the proximity of genes influencing breed-defining traits will have reduced variation (a selective sweep) and will show divergence in allele frequency. Consequently, low-resolution genomic scans can potentially be used to identify regions containing genes that have a major influence on breed-defining traits. We model the process of breed formation and show that the probability of two or three adjacent marker loci showing a spurious signal of selection within at least one breed (i.e., Type I error or false-positive rate) is low if highly variable and moderately spaced markers are utilized. We also use simulations with selection to demonstrate that even a moderately spaced set of highly polymorphic markers (e.g., one every 0.8 cM) has high power to detect regions targeted by strong artificial selection in dogs. Further, we show that a gene responsible for black coat color in the Large Munsterlander has a 40-Mb region surrounding the gene that is very low in heterozygosity for microsatellite markers. Similarly, we survey 302 microsatellite markers in the Dachshund and find three linked monomorphic microsatellite markers all within a 10-Mb region on chromosome 3. This region contains the FGFR3 gene, which is responsible for achondroplasia in humans, but not in dogs. Consequently, our results suggest that the causative mutation is a gene or regulatory region closely linked to FGFR3.

A Substantive Process Analysis of Responses to Items from the Multistate Bar Examination

ERIC Educational Resources Information Center

Bonner, Sarah M.; D'Agostino, Jerome V.

2012-01-01

We investigated examinees' cognitive processes while they solved selected items from the Multistate Bar Exam (MBE), a high-stakes professional certification examination. We focused on ascertaining those mental processes most frequently used by examinees, and the most common types of errors in their thinking. We compared the relationships between…

Plating Processes Utilizing High Intensity Acoustic Beams

NASA Technical Reports Server (NTRS)

Oeftering, Richard C. (Inventor); Denofrio, Charles (Inventor)

2002-01-01

A system and a method for selective plating processes are disclosed which use directed beams of high intensity acoustic waves to create non-linear effects that alter and improve the plating process. The directed beams are focused on the surface of an object, which in one embodiment is immersed in a plating solution, and in another embodiment is suspended above a plating solution. The plating processes provide precise control of the thickness of the layers of the plating, while at the same time, in at least some incidents, eliminates the need for masking.

Determination of Process Parameters for High-Density, Ti-6Al-4V Parts Using Additive Manufacturing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kamath, C.

In our earlier work, we described an approach for determining the process parameters that re- sult in high-density parts manufactured using the additive-manufacturing process of selective laser melting (SLM). Our approach, which combines simple simulations and experiments, was demon- strated using 316L stainless steel. We have also used the approach successfully for several other materials. This short note summarizes the results of our work in determining process parameters for Ti-6Al-4V using a Concept Laser M2 system.

Membrane processes in biotechnology: an overview.

PubMed

Charcosset, Catherine

2006-01-01

Membrane processes are increasingly reported for various applications in both upstream and downstream technology, such as the established ultrafiltration and microfiltration, and emerging processes as membrane bioreactors, membrane chromatography, and membrane contactors for the preparation of emulsions and particles. Membrane systems exploit the inherent properties of high selectivity, high surface-area-per-unit-volume, and their potential for controlling the level of contact and/or mixing between two phases. This review presents these various membrane processes by focusing more precisely on membrane materials, module design, operating parameters and the large range of possible applications.

Visual analytics in cheminformatics: user-supervised descriptor selection for QSAR methods.

PubMed

Martínez, María Jimena; Ponzoni, Ignacio; Díaz, Mónica F; Vazquez, Gustavo E; Soto, Axel J

2015-01-01

The design of QSAR/QSPR models is a challenging problem, where the selection of the most relevant descriptors constitutes a key step of the process. Several feature selection methods that address this step are concentrated on statistical associations among descriptors and target properties, whereas the chemical knowledge is left out of the analysis. For this reason, the interpretability and generality of the QSAR/QSPR models obtained by these feature selection methods are drastically affected. Therefore, an approach for integrating domain expert's knowledge in the selection process is needed for increase the confidence in the final set of descriptors. In this paper a software tool, which we named Visual and Interactive DEscriptor ANalysis (VIDEAN), that combines statistical methods with interactive visualizations for choosing a set of descriptors for predicting a target property is proposed. Domain expertise can be added to the feature selection process by means of an interactive visual exploration of data, and aided by statistical tools and metrics based on information theory. Coordinated visual representations are presented for capturing different relationships and interactions among descriptors, target properties and candidate subsets of descriptors. The competencies of the proposed software were assessed through different scenarios. These scenarios reveal how an expert can use this tool to choose one subset of descriptors from a group of candidate subsets or how to modify existing descriptor subsets and even incorporate new descriptors according to his or her own knowledge of the target property. The reported experiences showed the suitability of our software for selecting sets of descriptors with low cardinality, high interpretability, low redundancy and high statistical performance in a visual exploratory way. Therefore, it is possible to conclude that the resulting tool allows the integration of a chemist's expertise in the descriptor selection process with a low cognitive effort in contrast with the alternative of using an ad-hoc manual analysis of the selected descriptors. Graphical abstractVIDEAN allows the visual analysis of candidate subsets of descriptors for QSAR/QSPR. In the two panels on the top, users can interactively explore numerical correlations as well as co-occurrences in the candidate subsets through two interactive graphs.

Perceptual load manipulation reveals sensitivity of the face-selective N170 to attention.

PubMed

Mohamed, Tarik N; Neumann, Markus F; Schweinberger, Stefan R

2009-05-27

It has been controversial whether the face-sensitive N170 is affected by selective attention. We manipulated attention sensu Lavie's perceptual load theory to short (200 ms) presentations of task-irrelevant unfamiliar faces or houses, while participants identified superimposed target letters 'X' versus 'N'. These targets were strings of either six identical (low load) or six different letters (high load). Under low load, we found a prominent face-selective N170 response. Under high load, however, we not only observed a dramatic reduction of the face N170 but also an unexpected enhancement of the house N170, such that face selectivity was almost completely lost. We conclude that the early stages of face processing indexed by the N170 strongly depend on selective attention.

Construction of titanium dioxide nanorod/graphite microfiber hybrid electrodes for a high performance electrochemical glucose biosensor

NASA Astrophysics Data System (ADS)

Zhang, Jian; Yu, Xin; Guo, Weibo; Qiu, Jichuan; Mou, Xiaoning; Li, Aixue; Liu, Hong

2016-04-01

The demand for a highly sensitive and selective glucose biosensor which can be used for implantable or on-time monitoring is constantly increasing. In this work, TiO2 nanorods were synthesized in situ on the surface of graphite microfibers to yield TiO2 nanorod/graphite microfiber hybrid electrodes. The TiO2 nanorods not only retain the high activity of the immobilized glucose molecule, but also promote the direct electron transfer process on the electrode surface. As a working electrode in an electrochemical glucose biosensor in a flowing system, the microfiber hybrid electrodes exhibit high sensitivity, selectivity and stability. Due to its simplicity, low cost, high stability, and unique morphology, the TiO2 nanorod/graphite microfiber hybrid electrode is expected to be an excellent candidate for an implantable biosensor or for in situ flow monitoring.The demand for a highly sensitive and selective glucose biosensor which can be used for implantable or on-time monitoring is constantly increasing. In this work, TiO2 nanorods were synthesized in situ on the surface of graphite microfibers to yield TiO2 nanorod/graphite microfiber hybrid electrodes. The TiO2 nanorods not only retain the high activity of the immobilized glucose molecule, but also promote the direct electron transfer process on the electrode surface. As a working electrode in an electrochemical glucose biosensor in a flowing system, the microfiber hybrid electrodes exhibit high sensitivity, selectivity and stability. Due to its simplicity, low cost, high stability, and unique morphology, the TiO2 nanorod/graphite microfiber hybrid electrode is expected to be an excellent candidate for an implantable biosensor or for in situ flow monitoring. Electronic supplementary information (ESI) available. See DOI: 10.1039/c6nr01360k

Combined polyhydroxyalkanoates (PHA) and 1,3-propanediol production from crude glycerol: Selective conversion of volatile fatty acids into PHA by mixed microbial consortia.

PubMed

Burniol-Figols, Anna; Varrone, Cristiano; Le, Simone Balzer; Daugaard, Anders Egede; Skiadas, Ioannis V; Gavala, Hariklia N

2018-06-01

Crude glycerol is an important by-product of the biodiesel industry, which can be converted into volatile fatty acids (VFA) and/or 1,3-propanediol (1,3-PDO) by fermentation. In this study, a selective conversion of VFA to polyhydroxyalkanoates (PHA) was attained while leaving 1,3-PDO in the supernatant by means of mixed microbial consortia selection strategies. The process showed highly reproducible results in terms of PHA yield, 0.99 ± 0.07 C mol PHA/C mol S (0.84 g COD PHA/g COD S), PHA content (76 ± 3.1 g PHA/100 g TSS) and 1,3-PDO recovery (99 ± 2.1%). The combined process had an ultimate yield from crude glycerol of 0.19 g COD PHA and 0.42 g COD 1,3-PDO per g of input COD. The novel enrichment strategy applied for selectively transforming fermentation by-products into a high value product (PHA) demonstrates the significance of the enrichment process for targeting specific bio-transformations and could potentially prove valuable for other biotechnological applications as well. Copyright © 2018 Elsevier Ltd. All rights reserved.

Prediction of human disease-associated phosphorylation sites with combined feature selection approach and support vector machine.

PubMed

Xu, Xiaoyi; Li, Ao; Wang, Minghui

2015-08-01

Phosphorylation is a crucial post-translational modification, which regulates almost all cellular processes in life. It has long been recognised that protein phosphorylation has close relationship with diseases, and therefore many researches are undertaken to predict phosphorylation sites for disease treatment and drug design. However, despite the success achieved by these approaches, no method focuses on disease-associated phosphorylation sites prediction. Herein, for the first time the authors propose a novel approach that is specially designed to identify associations between phosphorylation sites and human diseases. To take full advantage of local sequence information, a combined feature selection method-based support vector machine (CFS-SVM) that incorporates minimum-redundancy-maximum-relevance filtering process and forward feature selection process is developed. Performance evaluation shows that CFS-SVM is significantly better than the widely used classifiers including Bayesian decision theory, k nearest neighbour and random forest. With the extremely high specificity of 99%, CFS-SVM can still achieve a high sensitivity. Besides, tests on extra data confirm the effectiveness and general applicability of CFS-SVM approach on a variety of diseases. Finally, the analysis of selected features and corresponding kinases also help the understanding of the potential mechanism of disease-phosphorylation relationships and guide further experimental validations.

Optimal design and experimental validation of a simulated moving bed chromatography for continuous recovery of formic acid in a model mixture of three organic acids from Actinobacillus bacteria fermentation.

PubMed

Park, Chanhun; Nam, Hee-Geun; Lee, Ki Bong; Mun, Sungyong

2014-10-24

The economically-efficient separation of formic acid from acetic acid and succinic acid has been a key issue in the production of formic acid with the Actinobacillus bacteria fermentation. To address this issue, an optimal three-zone simulated moving bed (SMB) chromatography for continuous separation of formic acid from acetic acid and succinic acid was developed in this study. As a first step for this task, the adsorption isotherm and mass-transfer parameters of each organic acid on the qualified adsorbent (Amberchrom-CG300C) were determined through a series of multiple frontal experiments. The determined parameters were then used in optimizing the SMB process for the considered separation. During such optimization, the additional investigation for selecting a proper SMB port configuration, which could be more advantageous for attaining better process performances, was carried out between two possible configurations. It was found that if the properly selected port configuration was adopted in the SMB of interest, the throughout and the formic-acid product concentration could be increased by 82% and 181% respectively. Finally, the optimized SMB process based on the properly selected port configuration was tested experimentally using a self-assembled SMB unit with three zones. The SMB experimental results and the relevant computer simulation verified that the developed process in this study was successful in continuous recovery of formic acid from a ternary organic-acid mixture of interest with high throughput, high purity, high yield, and high product concentration. Copyright © 2014 Elsevier B.V. All rights reserved.

Comparison of a rational vs. high throughput approach for rapid salt screening and selection.

PubMed

Collman, Benjamin M; Miller, Jonathan M; Seadeek, Christopher; Stambek, Julie A; Blackburn, Anthony C

2013-01-01

In recent years, high throughput (HT) screening has become the most widely used approach for early phase salt screening and selection in a drug discovery/development setting. The purpose of this study was to compare a rational approach for salt screening and selection to those results previously generated using a HT approach. The rational approach involved a much smaller number of initial trials (one salt synthesis attempt per counterion) that were selected based on a few strategic solubility determinations of the free form combined with a theoretical analysis of the ideal solvent solubility conditions for salt formation. Salt screening results for sertraline, tamoxifen, and trazodone using the rational approach were compared to those previously generated by HT screening. The rational approach produced similar results to HT screening, including identification of the commercially chosen salt forms, but with a fraction of the crystallization attempts. Moreover, the rational approach provided enough solid from the very initial crystallization of a salt for more thorough and reliable solid-state characterization and thus rapid decision-making. The crystallization techniques used in the rational approach mimic larger-scale process crystallization, allowing smoother technical transfer of the selected salt to the process chemist.

Learning from Past Classification Errors: Exploring Methods for Improving the Performance of a Deep Learning-based Building Extraction Model through Quantitative Analysis of Commission Errors for Optimal Sample Selection

NASA Astrophysics Data System (ADS)

Swan, B.; Laverdiere, M.; Yang, L.

2017-12-01

In the past five years, deep Convolutional Neural Networks (CNN) have been increasingly favored for computer vision applications due to their high accuracy and ability to generalize well in very complex problems; however, details of how they function and in turn how they may be optimized are still imperfectly understood. In particular, their complex and highly nonlinear network architecture, including many hidden layers and self-learned parameters, as well as their mathematical implications, presents open questions about how to effectively select training data. Without knowledge of the exact ways the model processes and transforms its inputs, intuition alone may fail as a guide to selecting highly relevant training samples. Working in the context of improving a CNN-based building extraction model used for the LandScan USA gridded population dataset, we have approached this problem by developing a semi-supervised, highly-scalable approach to select training samples from a dataset of identified commission errors. Due to the large scope this project, tens of thousands of potential samples could be derived from identified commission errors. To efficiently trim those samples down to a manageable and effective set for creating additional training sample, we statistically summarized the spectral characteristics of areas with rates of commission errors at the image tile level and grouped these tiles using affinity propagation. Highly representative members of each commission error cluster were then used to select sites for training sample creation. The model will be incrementally re-trained with the new training data to allow for an assessment of how the addition of different types of samples affects the model performance, such as precision and recall rates. By using quantitative analysis and data clustering techniques to select highly relevant training samples, we hope to improve model performance in a manner that is resource efficient, both in terms of training process and in sample creation.

High throughput sequencing analysis of RNA libraries reveals the influences of initial library and PCR methods on SELEX efficiency.

PubMed

Takahashi, Mayumi; Wu, Xiwei; Ho, Michelle; Chomchan, Pritsana; Rossi, John J; Burnett, John C; Zhou, Jiehua

2016-09-22

The systemic evolution of ligands by exponential enrichment (SELEX) technique is a powerful and effective aptamer-selection procedure. However, modifications to the process can dramatically improve selection efficiency and aptamer performance. For example, droplet digital PCR (ddPCR) has been recently incorporated into SELEX selection protocols to putatively reduce the propagation of byproducts and avoid selection bias that result from differences in PCR efficiency of sequences within the random library. However, a detailed, parallel comparison of the efficacy of conventional solution PCR versus the ddPCR modification in the RNA aptamer-selection process is needed to understand effects on overall SELEX performance. In the present study, we took advantage of powerful high throughput sequencing technology and bioinformatics analysis coupled with SELEX (HT-SELEX) to thoroughly investigate the effects of initial library and PCR methods in the RNA aptamer identification. Our analysis revealed that distinct "biased sequences" and nucleotide composition existed in the initial, unselected libraries purchased from two different manufacturers and that the fate of the "biased sequences" was target-dependent during selection. Our comparison of solution PCR- and ddPCR-driven HT-SELEX demonstrated that PCR method affected not only the nucleotide composition of the enriched sequences, but also the overall SELEX efficiency and aptamer efficacy.

High throughput sequencing analysis of RNA libraries reveals the influences of initial library and PCR methods on SELEX efficiency

PubMed Central

Takahashi, Mayumi; Wu, Xiwei; Ho, Michelle; Chomchan, Pritsana; Rossi, John J.; Burnett, John C.; Zhou, Jiehua

2016-01-01

The systemic evolution of ligands by exponential enrichment (SELEX) technique is a powerful and effective aptamer-selection procedure. However, modifications to the process can dramatically improve selection efficiency and aptamer performance. For example, droplet digital PCR (ddPCR) has been recently incorporated into SELEX selection protocols to putatively reduce the propagation of byproducts and avoid selection bias that result from differences in PCR efficiency of sequences within the random library. However, a detailed, parallel comparison of the efficacy of conventional solution PCR versus the ddPCR modification in the RNA aptamer-selection process is needed to understand effects on overall SELEX performance. In the present study, we took advantage of powerful high throughput sequencing technology and bioinformatics analysis coupled with SELEX (HT-SELEX) to thoroughly investigate the effects of initial library and PCR methods in the RNA aptamer identification. Our analysis revealed that distinct “biased sequences” and nucleotide composition existed in the initial, unselected libraries purchased from two different manufacturers and that the fate of the “biased sequences” was target-dependent during selection. Our comparison of solution PCR- and ddPCR-driven HT-SELEX demonstrated that PCR method affected not only the nucleotide composition of the enriched sequences, but also the overall SELEX efficiency and aptamer efficacy. PMID:27652575

Flow Asymmetric Propargylation: Development of Continuous Processes for the Preparation of a Chiral β-Amino Alcohol.

PubMed

Li, Hui; Sheeran, Jillian W; Clausen, Andrew M; Fang, Yuan-Qing; Bio, Matthew M; Bader, Scott

2017-08-01

The development of a flow chemistry process for asymmetric propargylation using allene gas as a reagent is reported. The connected continuous process of allene dissolution, lithiation, Li-Zn transmetallation, and asymmetric propargylation provides homopropargyl β-amino alcohol 1 with high regio- and diastereoselectivity in high yield. This flow process enables practical use of an unstable allenyllithium intermediate. The process uses the commercially available and recyclable (1S,2R)-N-pyrrolidinyl norephedrine as a ligand to promote the highly diastereoselective (32:1) propargylation. Judicious selection of mixers based on the chemistry requirement and real-time monitoring of the process using process analytical technology (PAT) enabled stable and scalable flow chemistry runs. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

The Effects of Visual Complexity for Japanese Kanji Processing with High and Low Frequencies

ERIC Educational Resources Information Center

Tamaoka, Katsuo; Kiyama, Sachiko

2013-01-01

The present study investigated the effects of visual complexity for kanji processing by selecting target kanji from different stroke ranges of visually simple (2-6 strokes), medium (8-12 strokes), and complex (14-20 strokes) kanji with high and low frequencies. A kanji lexical decision task in Experiment 1 and a kanji naming task in Experiment 2…

Explosive Welding in the 1990's

NASA Technical Reports Server (NTRS)

Lalwaney, N. S.; Linse, V. D.

1985-01-01

Explosive bonding is a unique joining process with the serious potential to produce composite materials capable of fulfilling many of the high performance materials capable of fulfilling many of the high performance materials needs of the 1990's. The process has the technological versatility to provide a true high quality metallurgical compatible and incompatible systems. Metals routinely explosively bonded include a wide variety of combinations of reactive and refractory metals, low and high density metals and their alloys, corrosion resistant and high strength alloys, and common steels. The major advantage of the process is its ability to custom design and engineer composites with physical and/or mechanical properties that meet a specific or unusual performance requirement. Explosive bonding offers the designer unique opportunities in materials selection with unique combinations of properties and high integrity bonds that cannot be achieved by any other metal joining process. The process and some applications are discussed.

Waste separation and pretreatment using crystalline silicotitanate ion exchangers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tadros, M.E.; Miller, J.E.; Anthony, R.G.

1997-10-01

A new class of inorganic ion exchangers called crystalline silicotitanates (CSTs) has been developed jointly by Sandia National Laboratories and Texas A&M University to selectively remove Cs and other radionuclides from a wide spectrum of radioactive defense wastes. The CST exhibits high selectivity and affinity for Cs and Sr under a wide range of conditions. Tests show it can remove part-per-million concentrations of Cs{sup +} from highly alkaline, high-sodium simulated radioactive waste solutions modeled after those at Hanford, Oak Ridge, and Savannah River. The materials exhibit ion exchange properties based on ionic size selectivity. Specifically, crystalline lattice spacing is controlledmore » to be highly selective for Cs ions even in waste streams containing very high (5 to 10 M) concentrations of sodium. The CST technology is being demonstrated with actual waste at several DOE facilities. The use of inorganic ion exchangers. The inorganics are more resistant to chemical, thermal, and radiation degradation. Their high selectivities result in more efficient operations offering the possibility of a simple single-pass operation. In contrast, regenerable organic ion exchangers require additional processing equipment to handle the regeneration liquids and the eluant with the dissolved Cs.« less

Microstructure and Magnetic Properties of Magnetic Material Fabricated by Selective Laser Melting

NASA Astrophysics Data System (ADS)

Jhong, Kai Jyun; Huang, Wei-Chin; Lee, Wen Hsi

Selective Laser Melting (SLM) is a powder-based additive manufacturing which is capable of producing parts layer-by-layer from a 3D CAD model. The aim of this study is to adopt the selective laser melting technique to magnetic material fabrication. [1]For the SLM process to be practical in industrial use, highly specific mechanical properties of the final product must be achieved. The integrity of the manufactured components depend strongly on each single laser-melted track and every single layer, as well as the strength of the connections between them. In this study, effects of the processing parameters, such as the space distance of surface morphology is analyzed. Our hypothesis is that when a magnetic product is made by the selective laser melting techniques instead of traditional techniques, the finished component will have more precise and effective properties. This study analyzed the magnitudes of magnetic properties in comparison with different parameters in the SLM process and compiled a completed product to investigate the efficiency in contrast with products made with existing manufacturing processes.

Parameters in selective laser melting for processing metallic powders

NASA Astrophysics Data System (ADS)

Kurzynowski, Tomasz; Chlebus, Edward; Kuźnicka, Bogumiła; Reiner, Jacek

2012-03-01

The paper presents results of studies on Selective Laser Melting. SLM is an additive manufacturing technology which may be used to process almost all metallic materials in the form of powder. Types of energy emission sources, mainly fiber lasers and/or Nd:YAG laser with similar characteristics and the wavelength of 1,06 - 1,08 microns, are provided primarily for processing metallic powder materials with high absorption of laser radiation. The paper presents results of selected variable parameters (laser power, scanning time, scanning strategy) and fixed parameters such as the protective atmosphere (argon, nitrogen, helium), temperature, type and shape of the powder material. The thematic scope is very broad, so the work was focused on optimizing the process of selective laser micrometallurgy for producing fully dense parts. The density is closely linked with other two conditions: discontinuity of the microstructure (microcracks) and stability (repeatability) of the process. Materials used for the research were stainless steel 316L (AISI), tool steel H13 (AISI), and titanium alloy Ti6Al7Nb (ISO 5832-11). Studies were performed with a scanning electron microscope, a light microscopes, a confocal microscope and a μCT scanner.

Study on Desorption Process of n-Heptane and Methyl Cyclohexane Using UiO-66 with Hierarchical Pores.

PubMed

Chen, Sijia; Zhang, Lin; Zhang, Zhao; Qian, Gang; Liu, Zongjian; Cui, Qun; Wang, Haiyan

2018-06-06

UiO-66 (UiO for University of Oslo), is a zirconium-based MOF with reverse shape selectivity, gives an alternative way to produce high purity n-heptane used for the manufacture of high-purity pharmaceuticals. Couple of studies have shown that UiO-66 gives a high selectivity on the separation of n-/iso-alkanes. However, the microporous structure of UiO-66 causes poor mass transport during the desorption process. In this work, hierarchical-pore UiO-66 (H-UiO-66) was synthesized and utilized as an adsorbent of n-heptane (nHEP) and methyl cyclohexane (MCH) for systematically studying the desorption process of n/iso-alkanes. A suite of physical methods, including XRD patterns verified the UiO-66 structures and HRTEM showed the existence of hierarchical pores. N2 adsorption-desorption isotherms further confirmed the size distribution of hierarchical pores in H-UiO-66. Of particular note, the MCH/nHEP selectivity of H-UiO-66 is similar with UiO-66 in the same adsorption conditions, the desorption process of nHEP/MCH from H-UiO-66 is dramatically enhanced, viz, the desorption rates for nHEP/MCH from H-UiO-66 is enhanced by 30%/23% as comparing to UiO-66 at most. Moreover, desorption activation energy (Ed) derived from temperature-programmed desorption (TPD) experiments indicate that the Ed for nHEP/MCH is lower on H-UiO-66, i.e., the Ed of MCH on H-UiO-66 is ~37% lower than that on UiO-66 at most, leading to a milder condition for the desorption process. The introduction of hierarchical structures will be applicable for the optimization of desorption process during separation on porous materials.

Changes of Attention during Value-Based Reversal Learning Are Tracked by N2pc and Feedback-Related Negativity

PubMed Central

Oemisch, Mariann; Watson, Marcus R.; Womelsdorf, Thilo; Schubö, Anna

2017-01-01

Previously learned reward values can have a pronounced impact, behaviorally and neurophysiologically, on the allocation of selective attention. All else constant, stimuli previously associated with a high value gain stronger attentional prioritization than stimuli previously associated with a low value. The N2pc, an ERP component indicative of attentional target selection, has been shown to reflect aspects of this prioritization, by changes of mean amplitudes closely corresponding to selective enhancement of high value target processing and suppression of high value distractor processing. What has remained unclear so far is whether the N2pc also reflects the flexible and repeated behavioral adjustments needed in a volatile task environment, in which the values of stimuli are reversed often and unannounced. Using a value-based reversal learning task, we found evidence that the N2pc amplitude flexibly and reversibly tracks value-based choices during the learning of reward associated stimulus colors. Specifically, successful learning of current value-contingencies was associated with reduced N2pc amplitudes, and this effect was more apparent for distractor processing, compared with target processing. In addition, following a value reversal the feedback related negativity(FRN), an ERP component that reflects feedback processing, was amplified and co-occurred with increased N2pc amplitudes in trials following low-value feedback. Importantly, participants that showed the greatest adjustment in N2pc amplitudes based on feedback were also the most efficient learners. These results allow further insight into how changes in attentional prioritization in an uncertain and volatile environment support flexible adjustments of behavior. PMID:29163113

Changes of Attention during Value-Based Reversal Learning Are Tracked by N2pc and Feedback-Related Negativity.

PubMed

Oemisch, Mariann; Watson, Marcus R; Womelsdorf, Thilo; Schubö, Anna

2017-01-01

Previously learned reward values can have a pronounced impact, behaviorally and neurophysiologically, on the allocation of selective attention. All else constant, stimuli previously associated with a high value gain stronger attentional prioritization than stimuli previously associated with a low value. The N2pc, an ERP component indicative of attentional target selection, has been shown to reflect aspects of this prioritization, by changes of mean amplitudes closely corresponding to selective enhancement of high value target processing and suppression of high value distractor processing. What has remained unclear so far is whether the N2pc also reflects the flexible and repeated behavioral adjustments needed in a volatile task environment, in which the values of stimuli are reversed often and unannounced. Using a value-based reversal learning task, we found evidence that the N2pc amplitude flexibly and reversibly tracks value-based choices during the learning of reward associated stimulus colors. Specifically, successful learning of current value-contingencies was associated with reduced N2pc amplitudes, and this effect was more apparent for distractor processing, compared with target processing. In addition, following a value reversal the feedback related negativity(FRN), an ERP component that reflects feedback processing, was amplified and co-occurred with increased N2pc amplitudes in trials following low-value feedback. Importantly, participants that showed the greatest adjustment in N2pc amplitudes based on feedback were also the most efficient learners. These results allow further insight into how changes in attentional prioritization in an uncertain and volatile environment support flexible adjustments of behavior.

Selectivity of β-Sitosterol Imprinted Polymers as Adsorbent

NASA Astrophysics Data System (ADS)

Fauziah, St.; Hariani Soekamto, Nunuk; Taba, Paulina; Bachri Amran, Muh

2018-03-01

Molecularly Imprinted Polymers (MIPs) are smart materials that have been used as adsorbents in separation processes of compounds because they have a memorial effect to a certain compound. In this research, MIP synthesized was used as adsorbent for β-sitosterol. The objective of the research was to know the selectivity of MIP in adsorbing β-sitosterol. The concentrations of β-sitosterol after adsorption and desorption were analyzed by a UV-Vis spectrophotometer and the selectivity test was analyzed by HPLC. Result showed that the MIP had high adsorption ability ( qe ). The recovery of β-sitosterol from MIP for the adsorption-desorption process was 68.48%. The MIP was very selective to β-sitosterol compared to cholesterol because it can adsorb β-sitosterol as many as 100%, whereas the adsorption of cholesterol was only 30.27 %.

Processes for producing low cost, high efficiency silicon solar cells

DOEpatents

Rohatgi, Ajeet; Doshi, Parag; Tate, John Keith; Mejia, Jose; Chen, Zhizhang

1998-06-16

Processes which utilize rapid thermal processing (RTP) are provided for inexpensively producing high efficiency silicon solar cells. The RTP processes preserve minority carrier bulk lifetime .tau. and permit selective adjustment of the depth of the diffused regions, including emitter and back surface field (bsf), within the silicon substrate. In a first RTP process, an RTP step is utilized to simultaneously diffuse phosphorus and aluminum into the front and back surfaces, respectively, of a silicon substrate. Moreover, an in situ controlled cooling procedure preserves the carrier bulk lifetime .tau. and permits selective adjustment of the depth of the diffused regions. In a second RTP process, both simultaneous diffusion of the phosphorus and aluminum as well as annealing of the front and back contacts are accomplished during the RTP step. In a third RTP process, the RTP step accomplishes simultaneous diffusion of the phosphorus and aluminum, annealing of the contacts, and annealing of a double-layer antireflection/passivation coating SiN/SiO.sub.x. In a fourth RTP process, the process of applying front and back contacts is broken up into two separate respective steps, which enhances the efficiency of the cells, at a slight time expense. In a fifth RTP process, a second RTP step is utilized to fire and adhere the screen printed or evaporated contacts to the structure.

Mental Aptitude and Comprehension of Time-Compressed and Compressed-Expanded Listening Selections.

ERIC Educational Resources Information Center

Sticht, Thomas G.

The comprehensibility of materials compressed and then expanded by means of an electromechanical process was tested with 280 Army inductees divided into groups of high and low mental aptitude. Three short listening selections relating to military activities were subjected to compression and compression-expansion to produce seven versions. Data…

A Case Study Analysis of Middle School Principals' Teacher Selection Criteria

ERIC Educational Resources Information Center

Woodburn, Jane Lai

2012-01-01

The hiring of middle school teachers to positively impact student achievement--is this a process of teacher selection or teacher attraction for schools, respectively, with low teacher turnover and schools with high teacher turnover? Since research indicates that the most important variable influencing student achievement is having a highly…

76 FR 79712 - Report on the Selection of Eligible Countries for Fiscal Year 2012

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-22

... quantitative elements of the selection criteria (i.e., on the policy indicators) were not chosen as eligible... making improvements in the microfinance regulatory system. These activities allowed the Government of... process. There is a high-capacity and experienced MCA team already in operation, and the Government of El...

College-Bound Digest. Valuable Information from Prominent Educators for all College-Bound Students.

ERIC Educational Resources Information Center

Who's Who among American High School Students, Northbrook, IL.

This monograph about the college selection process is desigend to help students explore choices and options. It contains 20 articles, designed to complement the counselor's guidance efforts. These are: (1) "Getting the Most from Your High School Counselor," (James Warfield); (2) "The Use of the SAT at Selective Colleges,"…

Blind column selection protocol for two-dimensional high performance liquid chromatography.

PubMed

Burns, Niki K; Andrighetto, Luke M; Conlan, Xavier A; Purcell, Stuart D; Barnett, Neil W; Denning, Jacquie; Francis, Paul S; Stevenson, Paul G

2016-07-01

The selection of two orthogonal columns for two-dimensional high performance liquid chromatography (LC×LC) separation of natural product extracts can be a labour intensive and time consuming process and in many cases is an entirely trial-and-error approach. This paper introduces a blind optimisation method for column selection of a black box of constituent components. A data processing pipeline, created in the open source application OpenMS®, was developed to map the components within the mixture of equal mass across a library of HPLC columns; LC×LC separation space utilisation was compared by measuring the fractional surface coverage, fcoverage. It was found that for a test mixture from an opium poppy (Papaver somniferum) extract, the combination of diphenyl and C18 stationary phases provided a predicted fcoverage of 0.48 and was matched with an actual usage of 0.43. OpenMS®, in conjunction with algorithms designed in house, have allowed for a significantly quicker selection of two orthogonal columns, which have been optimised for a LC×LC separation of crude extractions of plant material. Copyright © 2016 Elsevier B.V. All rights reserved.

16 CFR 1107.21 - Periodic testing.

Code of Federal Regulations, 2012 CFR

2012-01-01

... samples selected for testing pass the test, there is a high degree of assurance that the other untested... determining the testing interval include, but are not limited to, the following: (i) High variability in test... process management techniques and tests provide a high degree of assurance of compliance if they are not...

16 CFR § 1107.21 - Periodic testing.

Code of Federal Regulations, 2013 CFR

2013-01-01

... samples selected for testing pass the test, there is a high degree of assurance that the other untested... determining the testing interval include, but are not limited to, the following: (i) High variability in test... process management techniques and tests provide a high degree of assurance of compliance if they are not...

16 CFR 1107.21 - Periodic testing.

Code of Federal Regulations, 2014 CFR

2014-01-01

... samples selected for testing pass the test, there is a high degree of assurance that the other untested... determining the testing interval include, but are not limited to, the following: (i) High variability in test... process management techniques and tests provide a high degree of assurance of compliance if they are not...

High affinity ligands from in vitro selection: Complex targets

PubMed Central

Morris, Kevin N.; Jensen, Kirk B.; Julin, Carol M.; Weil, Michael; Gold, Larry

1998-01-01

Human red blood cell membranes were used as a model system to determine if the systematic evolution of ligands by exponential enrichment (SELEX) methodology, an in vitro protocol for isolating high-affinity oligonucleotides that bind specifically to virtually any single protein, could be used with a complex mixture of potential targets. Ligands to multiple targets were generated simultaneously during the selection process, and the binding affinities of these ligands for their targets are comparable to those found in similar experiments against pure targets. A secondary selection scheme, deconvolution-SELEX, facilitates rapid isolation of the ligands to targets of special interest within the mixture. SELEX provides high-affinity compounds for multiple targets in a mixture and might allow a means for dissecting complex biological systems. PMID:9501188

Explosion-assisted preparation of dispersed gold-bearing different-grade ore for selective mining

NASA Astrophysics Data System (ADS)

Trubachev, AI; Zykov, NV

2017-02-01

It is found that there are transient zones (between quality and off-quality ore areas) with the respective content of useful component in an ore body, and a variant of explosive treatment of such zones before the selective mining is put forward. Practicability of two processing technologies is evaluated: processing of high-grade and low-grade ore from the transient zones and heap leaching of metals from the low-grade and impoverished ore. Open mining technology is conventional truck-and-shovel scheme, with distributed ore flows to processing plant and (or) to heap leaching, which generally enhances the mine efficiency.

PHASTpep: Analysis Software for Discovery of Cell-Selective Peptides via Phage Display and Next-Generation Sequencing

PubMed Central

Dasa, Siva Sai Krishna; Kelly, Kimberly A.

2016-01-01

Next-generation sequencing has enhanced the phage display process, allowing for the quantification of millions of sequences resulting from the biopanning process. In response, many valuable analysis programs focused on specificity and finding targeted motifs or consensus sequences were developed. For targeted drug delivery and molecular imaging, it is also necessary to find peptides that are selective—targeting only the cell type or tissue of interest. We present a new analysis strategy and accompanying software, PHage Analysis for Selective Targeted PEPtides (PHASTpep), which identifies highly specific and selective peptides. Using this process, we discovered and validated, both in vitro and in vivo in mice, two sequences (HTTIPKV and APPIMSV) targeted to pancreatic cancer-associated fibroblasts that escaped identification using previously existing software. Our selectivity analysis makes it possible to discover peptides that target a specific cell type and avoid other cell types, enhancing clinical translatability by circumventing complications with systemic use. PMID:27186887

Wright's Shifting Balance Theory and the Diversification of Aposematic Signals

PubMed Central

Chouteau, Mathieu; Angers, Bernard

2012-01-01

Despite accumulating evidence for selection within natural systems, the importance of random genetic drift opposing Wright's and Fisher's views of evolution continue to be a subject of controversy. The geographical diversification of aposematic signals appears to be a suitable system to assess the factors involved in the process of adaptation since both theories were independently proposed to explain this phenomenon. In the present study, the effects of drift and selection were assessed from population genetics and predation experiments on poison-dart frogs, Ranitomaya imitator, of Northern Peru. We specifically focus on the transient zone between two distinct aposematic signals. In contrast to regions where high predation maintains a monomorphic aposematic signal, the transient zones are characterized by lowered selection and a high phenotypic diversity. As a result, the diversification of phenotypes may occur via genetic drift without a significant loss of fitness. These new phenotypes may then colonize alternative habitats if successfully recognized and avoided by predators. This study highlights the interplay between drift and selection as determinant processes in the adaptive diversification of aposematic signals. Results are consistent with the expectations of the Wright's shifting balance theory and represent, to our knowledge, the first empirical demonstration of this highly contested theory in a natural system. PMID:22470509

Neuro-immune modulation of the thymus microenvironment (review).

PubMed

Mignini, Fiorenzo; Sabbatini, Maurizio; Mattioli, Laura; Cosenza, Monica; Artico, Marco; Cavallotti, Carlo

2014-06-01

The thymus is the primary site for T-cell lympho-poiesis. Its function includes the maturation and selection of antigen specific T cells and selective release of these cells to the periphery. These highly complex processes require precise parenchymal organization and compartmentation where a plethora of signalling pathways occur, performing strict control on the maturation and selection processes of T lymphocytes. In this review, the main morphological characteristics of the thymus microenvironment, with particular emphasis on nerve fibers and neuropeptides were assessed, as both are responsible for neuro-immune‑modulation functions. Among several neurotransmitters that affect thymus function, we highlight the dopaminergic system as only recently has its importance on thymus function and lymphocyte physiology come to light.

Effect of the length of the cycle on biodegradable polymer production and microbial community selection in a sequencing batch reactor.

PubMed

Dionisi, Davide; Majone, Mauro; Vallini, Giovanni; Gregorio, Simona Di; Beccari, Mario

2007-01-01

The effect of the length of the cycle on the enrichment and selection of mixed cultures in sequencing batch reactors (SBRs) has been studied, with the aim of biodegradable polymers (namely, polyhydroxyalkanoates (PHAs)) production from organic wastes. At a fixed feed concentration (20 gCOD/L) and organic loading rate (20 gCOD/L/day), the SBR was operated at different lengths of the cycle, in the range 1-8 h. Process performance was measured by considering the rates and yields of polymer storage and of the competing phenomenon of growth. The selected biomass was enriched with microorganisms that were able to store PHAs at high rates and yields only when the length of the cycle was 2 or 4 h, even though in these conditions the process was unstable. On the other hand, when the length of the cycle was 1 or 8 h, the dynamic response of the selected microorganisms was dominated by growth. The best process performance was characterized by storage rates in the range 500-600 mgCOD/gCOD/h and storage yields of 0.45-0.55 COD/COD. The corresponding productivity of the process was in the range 0.25-0.30 gPHA/L/h, the highest values obtained until now for mixed cultures. The microbial composition of the selected biomasses was analyzed through denaturing gradient gel electrophoresis (DGGE) and reverse-transcriptase denaturing gradient gel electrophoresis (RT-DGGE). The instability of the runs characterized by high storage rate was associated with a higher microbial heterogeneity compared to the runs with a stable growth response.

Cadmium Alternatives for High-Strength Steel JTP. Phase 2

DTIC Science & Technology

2007-01-24

Standard Form 298 (Rev. 8-98) Prescribed by ANSI Std Z39-18 U.S. AIR FORCE Project Overview Objective Assess DoD- selected cadmium alternatives in...focused) – Phase III (fatigue testing focused) • Down- selection of candidates for further testing after each phase of testing is complete (Phases I...Laboratories – Mr. John Marshall U.S. AIR FORCE Phase I Overview and Selection Process – Traditional plating (primary coatings): • Sputtered Aluminum

HOLE-BLOCKING LAYERS FOR SILICON/ORGANIC HETEROJUNCTIONS: A NEW CLASS OF HIGH-EFFICIENCY LOW-COST PV

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sturm, James

This project is the first investigation of the use of thin titanium dioxide layers on silicon as a hole-blocking / electron-transparent selective contact to silicon. The work was motivated by the goal of a high-efficiency low-cost silicon-based solar cells that could be processed entirely at low temperature (300 Degree Celsius) or less, without requiring plasma-processing.

Intentional and automatic processing of numerical information in mathematical anxiety: testing the influence of emotional priming.

PubMed

Ashkenazi, Sarit

2018-02-05

Current theoretical approaches suggest that mathematical anxiety (MA) manifests itself as a weakness in quantity manipulations. This study is the first to examine automatic versus intentional processing of numerical information using the numerical Stroop paradigm in participants with high MA. To manipulate anxiety levels, we combined the numerical Stroop task with an affective priming paradigm. We took a group of college students with high MA and compared their performance to a group of participants with low MA. Under low anxiety conditions (neutral priming), participants with high MA showed relatively intact number processing abilities. However, under high anxiety conditions (mathematical priming), participants with high MA showed (1) higher processing of the non-numerical irrelevant information, which aligns with the theoretical view regarding deficits in selective attention in anxiety and (2) an abnormal numerical distance effect. These results demonstrate that abnormal, basic numerical processing in MA is context related.

Estimating and mapping ecological processes influencing microbial community assembly

DOE PAGES

Stegen, James C.; Lin, Xueju; Fredrickson, Jim K.; ...

2015-05-01

Ecological community assembly is governed by a combination of (i) selection resulting from among-taxa differences in performance; (ii) dispersal resulting from organismal movement; and (iii) ecological drift resulting from stochastic changes in population sizes. The relative importance and nature of these processes can vary across environments. Selection can be homogeneous or variable, and while dispersal is a rate, we conceptualize extreme dispersal rates as two categories; dispersal limitation results from limited exchange of organisms among communities, and homogenizing dispersal results from high levels of organism exchange. To estimate the influence and spatial variation of each process we extend a recentlymore » developed statistical framework, use a simulation model to evaluate the accuracy of the extended framework, and use the framework to examine subsurface microbial communities over two geologic formations. For each subsurface community we estimate the degree to which it is influenced by homogeneous selection, variable selection, dispersal limitation, and homogenizing dispersal. Our analyses revealed that the relative influences of these ecological processes vary substantially across communities even within a geologic formation. We further identify environmental and spatial features associated with each ecological process, which allowed mapping of spatial variation in ecological-process-influences. The resulting maps provide a new lens through which ecological systems can be understood; in the subsurface system investigated here they revealed that the influence of variable selection was associated with the rate at which redox conditions change with subsurface depth.« less

Surface-Enhanced Separation of Water from Hydrocarbons: Potential Dewatering Membranes for the Catalytic Fast Pyrolysis of Pine Biomass

DOE PAGES

Engtrakul, Dr. Chaiwat; Hu, Michael Z.; Bischoff, Brian L; ...

2016-01-01

The impact of surface-selective coatings on water permeation through a membrane when exposed to catalytic fast pyrolysis (CFP) vapor products was studied by tailoring the surface properties of the membrane coating from superhydrophilic to superhydrophobic. Our approach utilized high-performance architectured surface-selective (HiPAS) membranes that were inserted after a CFP reactor. At this insertion point, the inner wall surface of a tubular membrane was exposed to a mixture of water and upgraded product vapors, including light gases and deoxygenated hydrocarbons. Under proper membrane operating conditions, a high selectivity for water over 1-ring upgraded biomass pyrolysis hydrocarbons was observed due to amore » surface-enhanced capillary condensation process. Owing to this surface-enhanced effect, HiPAS membranes have the potential to enable high flux separations suggesting that water can be selectively removed from the CFP product vapors.« less

Selective removal of mercury from aqueous solutions using thiolated cross-linked polyethylenimine

NASA Astrophysics Data System (ADS)

Saad, Dalia M.; Cukrowska, Ewa M.; Tutu, Hlanganani

2013-06-01

A successful approach to develop an insoluble form of polyethylenimine with a thiol-based functional group for selective removal of Hg(II) from aqueous solutions is reported. The selectivity of the modified polymer for Hg(II) as well as its ability to be regenerated for re-use has been studied. The synthesised polymer exhibited high selectivity for Hg(II) with high removal efficiency of up to 97 %, even in the presence of competing ions. The Freundlich isotherm was found to best fit and describe the experimental data. The pseudo-second-order equation explains the adsorption kinetics most effectively implying chemisorption. The thermodynamic study of the adsorption process revealed high activation energies >41 kJ mol-1, further confirming chemisorption as the mechanism of interaction between mercury ions and the polymer surface. The polymer exhibited good potential for re-use after many cycles of regeneration, giving good removal efficiency up to the fifth cycle.

Photostable and Low-Toxic Yellow-Green Carbon Dots for Highly Selective Detection of Explosive 2,4,6-Trinitrophenol Based on the Dual Electron Transfer Mechanism.

PubMed

Ju, Bo; Wang, Yi; Zhang, Yu-Mo; Zhang, Ting; Liu, Zhihe; Li, Minjie; Xiao-An Zhang, Sean

2018-04-18

Advances in the development of fluorescent carbon dots (CDs) for detecting nitro-explosives have attracted great interest. However, developing long-wavelength luminescence CDs for highly selective determination of 2,4,6-trinitrophenol (TNP) and getting insight into the detection mechanism remain further to be investigated. Here, excitation-independent yellow-green emission CDs with good photostability and low biotoxicity were introduced for detecting TNP selectively. Then, two types of electron transfer (ET) processes including hydrogen-bond interaction-assisted ET and proton transfer-assisted ET are suggested to be responsible for their photophysical behavior. Finally, the visual detection of TNP has been successfully developed by a CD-based indicator paper. The facile, highly sensitive, and selective detection for TNP in both of a solution and a solid phase makes CDs potentially useful in environmental sensor applications.

Surface-Enhanced Separation of Water from Hydrocarbons: Potential Dewatering Membranes for the Catalytic Fast Pyrolysis of Pine Biomass

DOE Office of Scientific and Technical Information (OSTI.GOV)

Engtrakul, Chaiwat; Hu, Michael Z.; Bischoff, Brian L.

2016-10-20

The impact of surface-selective coatings on water permeation through a membrane when exposed to catalytic fast pyrolysis (CFP) vapor products was studied by tailoring the surface properties of the membrane coating from superhydrophilic to superhydrophobic. Our approach used high-performance architectured surface-selective (HiPAS) membranes that were inserted after a CFP reactor. At this insertion point, the inner wall surface of a tubular membrane was exposed to a mixture of water and upgraded product vapors, including light gases and deoxygenated hydrocarbons. Under proper membrane operating conditions, a high selectivity for water over one-ring upgraded biomass pyrolysis hydrocarbons was observed as a resultmore » of a surface-enhanced capillary condensation process. Owing to this surface-enhanced effect, HiPAS membranes have the potential to enable high flux separations, suggesting that water can be selectively removed from the CFP product vapors.« less

Unbiased feature selection in learning random forests for high-dimensional data.

PubMed

Nguyen, Thanh-Tung; Huang, Joshua Zhexue; Nguyen, Thuy Thi

2015-01-01

Random forests (RFs) have been widely used as a powerful classification method. However, with the randomization in both bagging samples and feature selection, the trees in the forest tend to select uninformative features for node splitting. This makes RFs have poor accuracy when working with high-dimensional data. Besides that, RFs have bias in the feature selection process where multivalued features are favored. Aiming at debiasing feature selection in RFs, we propose a new RF algorithm, called xRF, to select good features in learning RFs for high-dimensional data. We first remove the uninformative features using p-value assessment, and the subset of unbiased features is then selected based on some statistical measures. This feature subset is then partitioned into two subsets. A feature weighting sampling technique is used to sample features from these two subsets for building trees. This approach enables one to generate more accurate trees, while allowing one to reduce dimensionality and the amount of data needed for learning RFs. An extensive set of experiments has been conducted on 47 high-dimensional real-world datasets including image datasets. The experimental results have shown that RFs with the proposed approach outperformed the existing random forests in increasing the accuracy and the AUC measures.

Exploitation of data from breeding programs supports rapid implementation of genomic selection for key agronomic traits in perennial ryegrass.

PubMed

Pembleton, Luke W; Inch, Courtney; Baillie, Rebecca C; Drayton, Michelle C; Thakur, Preeti; Ogaji, Yvonne O; Spangenberg, German C; Forster, John W; Daetwyler, Hans D; Cogan, Noel O I

2018-06-02

Exploitation of data from a ryegrass breeding program has enabled rapid development and implementation of genomic selection for sward-based biomass yield with a twofold-to-threefold increase in genetic gain. Genomic selection, which uses genome-wide sequence polymorphism data and quantitative genetics techniques to predict plant performance, has large potential for the improvement in pasture plants. Major factors influencing the accuracy of genomic selection include the size of reference populations, trait heritability values and the genetic diversity of breeding populations. Global diversity of the important forage species perennial ryegrass is high and so would require a large reference population in order to achieve moderate accuracies of genomic selection. However, diversity of germplasm within a breeding program is likely to be lower. In addition, de novo construction and characterisation of reference populations are a logistically complex process. Consequently, historical phenotypic records for seasonal biomass yield and heading date over a 18-year period within a commercial perennial ryegrass breeding program have been accessed, and target populations have been characterised with a high-density transcriptome-based genotyping-by-sequencing assay. Ability to predict observed phenotypic performance in each successive year was assessed by using all synthetic populations from previous years as a reference population. Moderate and high accuracies were achieved for the two traits, respectively, consistent with broad-sense heritability values. The present study represents the first demonstration and validation of genomic selection for seasonal biomass yield within a diverse commercial breeding program across multiple years. These results, supported by previous simulation studies, demonstrate the ability to predict sward-based phenotypic performance early in the process of individual plant selection, so shortening the breeding cycle, increasing the rate of genetic gain and allowing rapid adoption in ryegrass improvement programs.

A core-substituted naphthalene diimide fluoride sensor.

PubMed

Bhosale, Sheshanath V; Bhosale, Sidhanath V; Kalyankar, Mohan B; Langford, Steven J

2009-12-03

The synthesis and characterization of a highly fluorescent core-substituted naphthalene diimide sensor (varphi = 0.34) bearing a bis-sulfonamide group is described. The compound shows a unique selectivity and reactivity for the fluoride ion over other anions in CHCl(3) by a two-stage deprotonation process leading to a colorimetric response. In DMSO solution, the sensor is shown to be highly selective for fluoride (K(a) approximately 10(6) M(-1)) over other anions with more pronounced changes in absorption characteristics.

Ion processing element with composite media

DOEpatents

Mann, Nick R.; Tranter, Troy J.; Todd, Terry A.; Sebesta, Ferdinand

2003-02-04

An ion processing element employing composite media disposed in a porous substrate, for facilitating removal of selected chemical species from a fluid stream. The ion processing element includes a porous fibrous glass substrate impregnated by composite media having one or more active components supported by a matrix material of polyacrylonitrile. The active components are effective in removing, by various mechanisms, one or more constituents from a fluid stream passing through the ion processing element. Due to the porosity and large surface area of both the composite medium and the substrate in which it is disposed, a high degree of contact is achieved between the active component and the fluid stream being processed. Further, the porosity of the matrix material and the substrate facilitates use of the ion processing element in high volume applications where it is desired to effectively process a high volume flows.

Ion processing element with composite media

DOEpatents

Mann, Nick R [Blackfoot, ID; Tranter, Troy J [Idaho Falls, ID; Todd, Terry A [Aberdeen, ID; Sebesta, Ferdinand [Prague, CZ

2009-03-24

An ion processing element employing composite media disposed in a porous substrate, for facilitating removal of selected chemical species from a fluid stream. The ion processing element includes a porous fibrous glass substrate impregnated by composite media having one or more active components supported by a matrix material of polyacrylonitrile. The active components are effective in removing, by various mechanisms, one or more constituents from a fluid stream passing through the ion processing element. Due to the porosity and large surface area of both the composite medium and the substrate in which it is disposed, a high degree of contact is achieved between the active component and the fluid stream being processed. Further, the porosity of the matrix material and the substrate facilitates use of the ion processing element in high volume applications where it is desired to effectively process a high volume flows.

Discovering highly obscured AGN with the Swift-BAT 100-month survey

NASA Astrophysics Data System (ADS)

Marchesi, Stefano; Ajello, Marco; Comastri, Andrea; Cusumano, Giancarlo; La Parola, Valentina; Segreto, Alberto

2017-01-01

In this talk, I present a new technique to find highly obscured AGN using the 100-month Swift-BAT survey. I will show the results of the combined Chandra and BAT spectral analysis in the 0.3-150 keV band of seven Seyfert 2 galaxies selected from the 100-month BAT catalog. We selected nearby (z<0.03) sources lacking of a ROSAT counterpart and never previously observed in the 0.3-10 keV energy range. All the objects are significantly obscured, having NH>1E23 cm-2 at a >99% confidence level, and one to three sources are candidate Compton thick Active Galactic Nuclei (CT-AGN), i.e., have NH>1E24 cm-2.Since the selection criteria we adopted have been extremely effective in detecting highly obscured AGN, further observations of these and other Seyfert 2 galaxies selected from the BAT 100-month catalog will allow us to create a statistically significant sample of highly obscured AGN, therefore better understanding the physics of the obscuration processes.

Selective elimination of long INterspersed element-1 expressing tumour cells by targeted expression of the HSV-TK suicide gene

PubMed Central

Chendeb, Mariam; Schneider, Robert; Davidson, Irwin; Fadloun, Anas

2017-01-01

In gene therapy, effective and selective suicide gene expression is crucial. We exploited the endogenous Long INterspersed Element-1 (L1) machinery often reactivated in human cancers to integrate the Herpes Simplex Virus Thymidine Kinase (HSV-TK) suicide gene selectively into the genome of cancer cells. We developed a plasmid-based system directing HSV-TK expression only when reverse transcribed and integrated in the host genome via the endogenous L1 ORF1/2 proteins and an Alu element. Delivery of these new constructs into cells followed by Ganciclovir (GCV) treatment selectively induced mortality of L1 ORF1/2 protein expressing cancer cells, but had no effect on primary cells that do not express L1 ORF1/2. This novel strategy for selective targeting of tumour cells provides high tolerability as the HSV-TK gene cannot be expressed without reverse transcription and integration, and high selectivity as these processes take place only in cancer cells expressing high levels of functional L1 ORF1/2. PMID:28415677

Transdiagnostic cognitive processes in high trait anger.

PubMed

Owen, John M

2011-03-01

Trait anger is a personality construct that refers to stable individual differences in the propensity to experience anger as an emotional state. The objective of this paper is to review relevant empirical studies in order to determine whether the transdiagnostic cognitive processes that have been identified across the DSM-IV Axis I disorders (specifically, selective attention, memory biases, reasoning biases and recurrent negative thinking) are also an underlying characteristic of high trait anger. On the basis of the review it is concluded that, whilst the research base is limited, there is good evidence that high trait anger is associated with selective attention to hostile social cues, the tendency to interpret the behaviour of others as indicating potential hostility and the tendency to ruminate over past anger-provoking experiences. The range of cognitive processes identified in high trait anger is consistent with those identified in the Axis I disorders. It is concluded that these findings provide support for (i) the broad applicability of the transdiagnostic approach as a theoretical framework for understanding a range of psychological conditions, not limited to the Axis I disorders, and (ii) the validity of conceptualising high trait anger as an aspect of personality functioning that is maintained, at least in part, by cognitive processes. Cognitive and motivational factors (specifically, beliefs and goals) that may underlie the hostile information-processing biases and recurrent negative thinking associated with high trait anger are discussed, and consideration is given to the clinical relevance of the findings of the review. Copyright © 2010 Elsevier Ltd. All rights reserved.

Punishment induced behavioural and neurophysiological variability reveals dopamine-dependent selection of kinematic movement parameters

PubMed Central

Galea, Joseph M.; Ruge, Diane; Buijink, Arthur; Bestmann, Sven; Rothwell, John C.

2013-01-01

Action selection describes the high-level process which selects between competing movements. In animals, behavioural variability is critical for the motor exploration required to select the action which optimizes reward and minimizes cost/punishment, and is guided by dopamine (DA). The aim of this study was to test in humans whether low-level movement parameters are affected by punishment and reward in ways similar to high-level action selection. Moreover, we addressed the proposed dependence of behavioural and neurophysiological variability on DA, and whether this may underpin the exploration of kinematic parameters. Participants performed an out-and-back index finger movement and were instructed that monetary reward and punishment were based on its maximal acceleration (MA). In fact, the feedback was not contingent on the participant’s behaviour but pre-determined. Blocks highly-biased towards punishment were associated with increased MA variability relative to blocks with either reward or without feedback. This increase in behavioural variability was positively correlated with neurophysiological variability, as measured by changes in cortico-spinal excitability with transcranial magnetic stimulation over the primary motor cortex. Following the administration of a DA-antagonist, the variability associated with punishment diminished and the correlation between behavioural and neurophysiological variability no longer existed. Similar changes in variability were not observed when participants executed a pre-determined MA, nor did DA influence resting neurophysiological variability. Thus, under conditions of punishment, DA-dependent processes influence the selection of low-level movement parameters. We propose that the enhanced behavioural variability reflects the exploration of kinematic parameters for less punishing, or conversely more rewarding, outcomes. PMID:23447607

Kin groups and trait groups: population structure and epidemic disease selection.

PubMed

Fix, A G

1984-10-01

A Monte Carlo simulation based on the population structure of a small-scale human population, the Semai Senoi of Malaysia, has been developed to study the combined effects of group, kin, and individual selection. The population structure resembles D.S. Wilson's structured deme model in that local breeding populations (Semai settlements) are subdivided into trait groups (hamlets) that may be kin-structured and are not themselves demes. Additionally, settlement breeding populations are connected by two-dimensional stepping-stone migration approaching 30% per generation. Group and kin-structured group selection occur among hamlets the survivors of which then disperse to breed within the settlement population. Genetic drift is modeled by the process of hamlet formation; individual selection as a deterministic process, and stepping-stone migration as either random or kin-structured migrant groups. The mechanism for group selection is epidemics of infectious disease that can wipe out small hamlets particularly if most adults become sick and social life collapses. Genetic resistance to a disease is an individual attribute; however, hamlet groups with several resistant adults are less likely to disintegrate and experience high social mortality. A specific human gene, hemoglobin E, which confers resistance to malaria, is studied as an example of the process. The results of the simulations show that high genetic variance among hamlet groups may be generated by moderate degrees of kin-structuring. This strong microdifferentiation provides the potential for group selection. The effect of group selection in this case is rapid increase in gene frequencies among the total set of populations. In fact, group selection in concert with individual selection produced a faster rate of gene frequency increase among a set of 25 populations than the rate within a single unstructured population subject to deterministic individual selection. Such rapid evolution with plausible rates of extinction, individual selection, and migration and a population structure realistic in its general form, has implications for specific human polymorphisms such as hemoglobin variants and for the more general problem of the tempo of evolution as well.

Transition to High School: School "Choice" & Freshman Year in Philadelphia

ERIC Educational Resources Information Center

Gold, Eva; Evans, Shani Adia; Haxton, Clarisse; Maluk, Holly; Mitchell, Cecily; Simon, Elaine; Good, Deborah

2010-01-01

The School District of Philadelphia's tiered system of selective, nonselective, and charter high schools, and the process for high school choice, has created real variation in the degree to which high schools can successfully meet the needs of ninth graders. Research has shown that the ninth grade year is critical in determining a student's…

Influences on selection of assistive technology for young children in South Africa: perspectives from rehabilitation professionals.

PubMed

van Niekerk, Karin; Dada, Shakila; Tönsing, Kerstin

2017-12-20

Selection of assistive technology for young children is a complex process. Within a context with limited resources, such as South Africa, research is needed to determine the factors influencing the assistive technology selection process, as these could ultimately either facilitate or hinder the availability and accessibility of affordable, adaptable, acceptable, and high quality assistive technology for this age group. Two asynchronous online focus groups were conducted with 16 rehabilitation professionals to identify the factors they perceived to influence the selection and provision of assistive technology to young children within the South African context. A process of deductive thematic analysis was followed by inductive analysis of the data. Components of the Assistive Technology Device Selection Framework were used as themes to guide the deductive analysis, followed by inductive analysis to create subthemes. The important role of the professional was highlighted in negotiating all the factors to consider in the assistive technology selection and provision process. Adaptation of the Assistive Technology Device Selection Framework is suggested in order to facilitate application to low resourced contexts, such as South Africa. Implications for rehabilitation Assistive technology selection is a complex process with factors pertaining to the users (child and family) of the assistive technology, as well as the rehabilitation professional recommending the assistive technology influencing the process. Although it may be an important factor, the availability of financial resources to purchase assistive technology is not the only determining factor in providing appropriate assistive technology to young children in contexts with limited resources. Formalized support, such as reflective supervision or mentorship programs should be facilitated and utilized by recommending professionals. Home and school visits during assessment ensure a good match between assistive technology and users within the particular context. Facilitating the availability of assistive technology for trial during assessment and/or for a period afterwards will increase the likelihood that appropriate recommendations for assistive technology are made.

Spin-on metal oxide materials with high etch selectivity and wet strippability

NASA Astrophysics Data System (ADS)

Yao, Huirong; Mullen, Salem; Wolfer, Elizabeth; McKenzie, Douglas; Rahman, Dalil; Cho, JoonYeon; Padmanaban, Munirathna; Petermann, Claire; Hong, SungEun; Her, YoungJun

2016-03-01

Metal oxide or metal nitride films are used as hard mask materials in semiconductor industry for patterning purposes due to their excellent etch resistances against the plasma etches. Chemical vapor deposition (CVD) or atomic layer deposition (ALD) techniques are usually used to deposit the metal containing materials on substrates or underlying films, which uses specialized equipment and can lead to high cost-of-ownership and low throughput. We have reported novel spin-on coatings that provide simple and cost effective method to generate metal oxide films possessing good etch selectivity and can be removed by chemical agents. In this paper, new spin-on Al oxide and Zr oxide hard mask formulations are reported. The new metal oxide formulations provide higher metal content compared to previously reported material of specific metal oxides under similar processing conditions. These metal oxide films demonstrate ultra-high etch selectivity and good pattern transfer capability. The cured films can be removed by various chemical agents such as developer, solvents or wet etchants/strippers commonly used in the fab environment. With high metal MHM material as an underlayer, the pattern transfer process is simplified by reducing the number of layers in the stack and the size of the nano structure is minimized by replacement of a thicker film ACL. Therefore, these novel AZ® spinon metal oxide hard mask materials can potentially be used to replace any CVD or ALD metal, metal oxide, metal nitride or spin-on silicon-containing hard mask films in 193 nm or EUV process.

Chemical recovery process using break up steam control to prevent smelt explosions

DOEpatents

Kohl, Arthur L.; Stewart, Albert E.

1988-08-02

An improvement in a chemical recovery process in which a hot liquid smelt is introduced into a dissolving tank containing a pool of green liquor. The improvement comprises preventing smelt explosions in the dissolving tank by maintaining a first selected superatmospheric pressure in the tank during normal operation of the furnace; sensing the pressure in the tank; and further impinging a high velocity stream of steam upon the stream of smelt whenever the pressure in the tank decreases below a second selected superatmospheric pressure which is lower than said first pressure.

Potential influence of selection criteria on the demographic composition of students in an Australian medical school

PubMed Central

2011-01-01

Background Prior to 1999 students entering our MBBS course were selected on academic performance alone. We have now evaluated the impact on the demographics of subsequent cohorts of our standard entry students (those entering directly from high school) of the addition to the selection process of an aptitude test (UMAT), a highly structured interview and a rural incentive program. Methods Students entering from 1985 to 1998, selected on academic performance alone (N = 1402), were compared to those from 1999 to 2011, selected on the basis of a combination of academic performance, interview score, and UMAT score together with the progressive introduction of a rural special entry pathway (N = 1437). Results Males decreased from 57% to 45% of the cohort, students of NE or SE Asian origin decreased from 30% to 13%, students born in Oceania increased from 52% to 69%, students of rural origin from 5% to 21% and those from independent high schools from 56% to 66%. The proportion of students from high schools with relative socio-educational disadvantage remained unchanged at approximately 10%. The changes reflect in part increasing numbers of female and independent high school applicants and the increasing rural quota. However, they were also associated with higher interview scores in females vs males and lower interview scores in those of NE and SE Asian origin compared to those born in Oceania or the UK. Total UMAT scores were unrelated to gender or region of origin. Conclusions The revised selection processes had no impact on student representation from schools with relative socio-educational disadvantage. However, the introduction of special entry quotas for students of rural origin and a structured interview, but not an aptitude test, were associated with a change in gender balance and ethnicity of students in an Australian undergraduate MBBS course. PMID:22111521

Design and Synthesis of Selective Estrogen Receptor beta Agonists and Their Pharmacology

NASA Astrophysics Data System (ADS)

Perera, K. L. Iresha Sampathi

Estrogens (17beta-estradiol, E2) have garnered considerable attention in influencing cognitive process in relation to phases of the menstrual cycle, aging and menopausal symptoms. However, hormone replacement therapy can have deleterious effects leading to breast and endometrial cancer, predominantly mediated by estrogen receptor-alpha (ERalpha) the major isoform present in the mammary gland and uterus. Further evidence supports a dominant role of estrogen receptor-beta (ERbeta) for improved cognitive effects such as enhanced hippocampal signaling and memory consolidation via estrogen activated signaling cascades. Creation of the ERbeta selective ligands is challenging due to high structural similarity of both receptors. Thus far, several ERbeta selective agonists have been developed, however, none of these have made it to clinical use due to their lower selectivity or considerable side effects. The research in this dissertation involved the design of non-steroidal ERbeta selective agonists for hippocampal memory consolidation. The step-wise process to achieve the ultimate goal of this research includes: (1) design and synthesis of (4-hydroxyphenyl)cyclohexyl or cycloheptyl derivatives, (2) in vitro biological evaluation of synthesized compounds to identify highly potent and selective candidates, and (3) in vivo biological evaluation of selected candidates for hippocampal memory consolidation. Several (4-hydroxyphenyl)cyclohexyl or cycloheptyl derivatives were synthesized having structural alterations on both aromatic and cyclohexyl/heptyl ring scaffolds. ERbeta agonist potency was initially evaluated in TR-FRET ERbeta ligand binding assay and compounds having high potency were re-evaluated in functional cell based assays for potency and ERbeta vs. ERalpha selectivity. Two compounds from each series, ISP 163-PK4 and ISP 358-2 were identified as most selective ERbeta agonists. Both compounds revealed high metabolic stability, solubility and no cross reactivity towards other nuclear receptors. In vivo efficiency of ISP 358-2 was evaluated in ovariectomized mice (C57BL/6) with object recognition (OR) and object placement (OP) tasks. The results indicate improved memory consolidation at 100 pg/ hemisphere and 0.5 mg/Kg via DH infusion and IP injection respectively. The information learned from this project serves as a foundation for development of other cycloheptyl/hexyl based ERbeta agonists or antagonists having acceptable pharmacological profiles.

Structure-Based Design of Highly Selective Inhibitors of the CREB Binding Protein Bromodomain.

PubMed

Denny, R Aldrin; Flick, Andrew C; Coe, Jotham; Langille, Jonathan; Basak, Arindrajit; Liu, Shenping; Stock, Ingrid; Sahasrabudhe, Parag; Bonin, Paul; Hay, Duncan A; Brennan, Paul E; Pletcher, Mathew; Jones, Lyn H; Chekler, Eugene L Piatnitski

2017-07-13

Chemical probes are required for preclinical target validation to interrogate novel biological targets and pathways. Selective inhibitors of the CREB binding protein (CREBBP)/EP300 bromodomains are required to facilitate the elucidation of biology associated with these important epigenetic targets. Medicinal chemistry optimization that paid particular attention to physiochemical properties delivered chemical probes with desirable potency, selectivity, and permeability attributes. An important feature of the optimization process was the successful application of rational structure-based drug design to address bromodomain selectivity issues (particularly against the structurally related BRD4 protein).

Reconceptualization of the Diffusion Process: An Application of Selected Principles from Modern Systems Theory.

ERIC Educational Resources Information Center

Silver, Wayne

A description of the communication behaviors in high innovation societies depends on the application of selected principles from modern systems theory. The first is the principle of equifinality which explains the activities of open systems. If the researcher views society as an open system, he frees himself from the client approach since society…

Differences in Gender Performance on Competitive Physics Selection Tests

ERIC Educational Resources Information Center

Wilson, Kate; Low, David; Verdon, Matthew; Verdon, Alix

2016-01-01

We have investigated gender differences in performance over the past eight years on the Australian Science Olympiad Exam (ASOE) for physics,which is taken by nearly 1000 high school students each year. The ASOE, run by Australian Science Innovations (ASI), is the initial stage of the process of selection of teams to represent Australia at the…

Incorporating Interpersonal Skills into Otolaryngology Resident Selection and Training.

PubMed

Lu-Myers, Yemeng; Myers, Christopher G

2018-01-01

Increasing attention has been paid to the selection of otolaryngology residents, a highly competitive process but one with room for improvement. A recent commentary in this journal recommended that residency programs more thoroughly incorporate theory and evidence from personnel psychology (part of the broader field of organizational science) in the resident selection process. However, the focus of this recommendation was limited to applicants' cognitive abilities and independent work-oriented traits (eg, conscientiousness). We broaden this perspective to consider critical interpersonal skills and traits that enhance resident effectiveness in interdependent health care organizations and we expand beyond the emphasis on selection to consider how these skills can be honed during residency. We advocate for greater use of standardized team-based care simulations, which can aid in assessing and developing the key interpersonal leadership skills necessary for success as an otolaryngology resident.

Carbon dioxide (hydrogen sulfide) membrane separations and WGS membrane reactor modeling for fuel cells

NASA Astrophysics Data System (ADS)

Huang, Jin

Acid-gas removal is of great importance in many environmental or energy-related processes. Compared to current commercial technologies, membrane-based CO2 and H2S capture has the advantages of low energy consumption, low weight and space requirement, simplicity of installation/operation, and high process flexibility. However, the large-scale application of the membrane separation technology is limited by the relatively low transport properties. In this study, CO2 (H2S)-selective polymeric membranes with high permeability and high selectivity have been studied based on the facilitated transport mechanism. The membrane showed facilitated effect for both CO2 and H2S. A CO2 permeability of above 2000 Barrers, a CO2/H2 selectivity of greater than 40, and a CO2/N2 selectivity of greater than 200 at 100--150°C were observed. As a result of higher reaction rate and smaller diffusing compound, the H2S permeability and H2S/H2 selectivity were about three times higher than those properties for CO2. The novel CO2-selective membrane has been applied to capture CO 2 from flue gas and natural gas. In the CO2 capture experiments from a gas mixture with N2 and H2, a permeate CO 2 dry concentration of greater than 98% was obtained by using steam as the sweep gas. In CO2/CH4 separation, decent CO 2 transport properties were obtained with a feed pressure up to 500 psia. With the thin-film composite membrane structure, significant increase on the CO2 flux was achieved with the decrease of the selective layer thickness. With the continuous removal of CO2, CO2-selective water-gas-shift (WGS) membrane reactor is a promising approach to enhance CO conversion and increase the purity of H2 at process pressure under relatively low temperature. The simultaneous reaction and transport process in the countercurrent WGS membrane reactor was simulated by using a one-dimensional non-isothermal model. The modeling results show that a CO concentration of less than 10 ppm and a H2 recovery of greater than 97% are achievable from reforming syngases. In an experimental study, the reversible WGS was shifted forward by removing CO2 so that the CO concentration was significantly decreased to less than 10 ppm. The modeling results agreed well with the experimental data.

Effect of key parameters on the selective acid leach of nickel from mixed nickel-cobalt hydroxide

NASA Astrophysics Data System (ADS)

Byrne, Kelly; Hawker, William; Vaughan, James

2017-01-01

Mixed nickel-cobalt hydroxide precipitate (MHP) is a relatively recent intermediate product in primary nickel production. The material is now being produced on a large scale (approximately 60,000 t/y Ni as MHP) at facilities in Australia (Ravensthorpe, First Quantum Minerals) and Papua New Guinea (Ramu, MCC/Highlands Pacific). The University of Queensland Hydrometallurgy research group developed a new processing technology to refine MHP based on a selective acid leach. This process provides a streamlined route to obtaining a high purity nickel product compared with conventional leaching / solvent extraction processes. The selective leaching of nickel from MHP involves stabilising manganese and cobalt into the solid phase using an oxidant. This paper describes a batch reactor study investigating the timing of acid and oxidant addition on the rate and extent of nickel, cobalt, manganese leached from industrial MHP. For the conditions studied, it is concluded that the simultaneous addition of acid and oxidant provide the best process outcomes.

Editorial highlighting and highly cited papers

NASA Astrophysics Data System (ADS)

Antonoyiannakis, Manolis

Editorial highlighting-the process whereby journal editors select, at the time of publication, a small subset of papers that are ostensibly of higher quality, importance or interest-is by now a widespread practice among major scientific journal publishers. Depending on the venue, and the extent to which editorial resources are invested in the process, highlighted papers appear as News & Views, Research Highlights, Perspectives, Editors' Choice, IOP Select, Editors' Summary, Spotlight on Optics, Editors' Picks, Viewpoints, Synopses, Editors' Suggestions, etc. Here, we look at the relation between highlighted papers and highly influential papers, which we define at two levels: having received enough citations to be among the (i) top few percent of their journal, and (ii) top 1% of all physics papers. Using multiple linear regression and multilevel regression modeling we examine the parameters associated with highly influential papers. We briefly comment on cause and effect relationships between citedness and highlighting of papers.

Selection and optimization of hits from a high-throughput phenotypic screen against Trypanosoma cruzi.

PubMed

Keenan, Martine; Alexander, Paul W; Chaplin, Jason H; Abbott, Michael J; Diao, Hugo; Wang, Zhisen; Best, Wayne M; Perez, Catherine J; Cornwall, Scott M J; Keatley, Sarah K; Thompson, R C Andrew; Charman, Susan A; White, Karen L; Ryan, Eileen; Chen, Gong; Ioset, Jean-Robert; von Geldern, Thomas W; Chatelain, Eric

2013-10-01

Inhibitors of Trypanosoma cruzi with novel mechanisms of action are urgently required to diversify the current clinical and preclinical pipelines. Increasing the number and diversity of hits available for assessment at the beginning of the discovery process will help to achieve this aim. We report the evaluation of multiple hits generated from a high-throughput screen to identify inhibitors of T. cruzi and from these studies the discovery of two novel series currently in lead optimization. Lead compounds from these series potently and selectively inhibit growth of T. cruzi in vitro and the most advanced compound is orally active in a subchronic mouse model of T. cruzi infection. High-throughput screening of novel compound collections has an important role to play in diversifying the trypanosomatid drug discovery portfolio. A new T. cruzi inhibitor series with good drug-like properties and promising in vivo efficacy has been identified through this process.

Motivation of Dutch high school students from various backgrounds for applying to study medicine: a qualitative study

PubMed Central

Wouters, Anouk; Croiset, Gerda; Isik, Ulviye; Kusurkar, Rashmi A

2017-01-01

Objective To explore high school students’ motivation for applying to study medicine and the factors that influence this. To find explanations for under-representation of minority students in medical education, descriptions of motivation of students with different background characteristics were compared. Design Qualitative phenomenological study using semistructured one-on-one interviews. Setting One predominantly white and one mixed high school in a large multicultural city in the Netherlands. The study was conducted in March–December 2015. Participants Twenty-four high school students, purposively sampled for demographic characteristics. Methods The analysis consisted of the coding of data using a template based on the motivation types (autonomous and controlled motivation) described by self-determination theory and open coding for factors that influence motivation. Results The main reasons for pursuing a medical career pertained to autonomous motivation (interest in science and helping people), but controlled motivation (eg, parental pressure, prestige) was also mentioned. Experiences with healthcare and patients positively influenced students’ autonomous motivation and served as a reality check for students’ expectations. Having to go through a selection process was an important demotivating factor, but did not prevent most students from applying. Having medical professionals in their network also sparked students’ interest, while facilitating easier access to healthcare experiences. Conclusions The findings showed a complex interplay between healthcare experiences, growing up in a medical family, selection processes and motivation. Healthcare experiences, often one of the selection criteria, help students to form autonomous motivation for studying medicine. However, such experiences as well as support in the selection process seem unequally accessible to students. As a result, under-represented students’ motivation decreases. Medical schools should be aware of this and could create opportunities to acquire healthcare experiences. High schools could incorporate internships as part of their study counselling programmes and offer tailor-made guidance to each individual student. PMID:28576893

Motivation of Dutch high school students from various backgrounds for applying to study medicine: a qualitative study.

PubMed

Wouters, Anouk; Croiset, Gerda; Isik, Ulviye; Kusurkar, Rashmi A

2017-06-02

To explore high school students' motivation for applying to study medicine and the factors that influence this. To find explanations for under-representation of minority students in medical education, descriptions of motivation of students with different background characteristics were compared. Qualitative phenomenological study using semistructured one-on-one interviews. One predominantly white and one mixed high school in a large multicultural city in the Netherlands. The study was conducted in March-December 2015. Twenty-four high school students, purposively sampled for demographic characteristics. The analysis consisted of the coding of data using a template based on the motivation types (autonomous and controlled motivation) described by self-determination theory and open coding for factors that influence motivation. The main reasons for pursuing a medical career pertained to autonomous motivation (interest in science and helping people), but controlled motivation (eg, parental pressure, prestige) was also mentioned. Experiences with healthcare and patients positively influenced students' autonomous motivation and served as a reality check for students' expectations. Having to go through a selection process was an important demotivating factor, but did not prevent most students from applying. Having medical professionals in their network also sparked students' interest, while facilitating easier access to healthcare experiences. The findings showed a complex interplay between healthcare experiences, growing up in a medical family, selection processes and motivation. Healthcare experiences, often one of the selection criteria, help students to form autonomous motivation for studying medicine. However, such experiences as well as support in the selection process seem unequally accessible to students. As a result, under-represented students' motivation decreases. Medical schools should be aware of this and could create opportunities to acquire healthcare experiences. High schools could incorporate internships as part of their study counselling programmes and offer tailor-made guidance to each individual student. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Fungal pretreatment of sweet sorghum bagasse with supplements: improvement in lignin degradation, selectivity and enzymatic saccharification.

PubMed

Mishra, Vartika; Jana, Asim K; Jana, Mithu Maiti; Gupta, Antriksh

2017-06-01

Sweet sorghum bagasse (SSB) from food processing and agricultural industry has attracted the attention for uses in production of biofuel, enzymes and other products. The alteration in lignocellulolytic enzymes by use of supplements in fungal pretreatment of SSB to achieve higher lignin degradation, selectivity value and enzymatic hydrolysis to fermentable sugar was studied. Fungal strain Coriolus versicolor was selected for pretreatment due to high ligninolytic and low cellulolytic enzyme production resulting in high lignin degradation and selectivity value. SSB was pretreated with supplements of veratryl alcohol, syringic acid, catechol, gallic acid, vanillin, guaiacol, CuSO 4 and MnSO 4 . The best results were obtained with CuSO 4 , gallic acid and syringic acid supplements. CuSO 4 increased the activities of laccase (4.9-fold) and polyphenol oxidase (1.9-fold); gallic acid increased laccase (3.5-fold) and manganese peroxidase (2.5-fold); and syringic acid increased laccase (5.6-fold), lignin peroxidase (13-fold) and arylalcohol oxidase (2.8-fold) resulting in enhanced lignin degradations and selectivity values than the control. Reduced cellulolytic enzyme activities resulted in high cellulose recovery. Enzymatic hydrolysis of pretreated SSB yielded higher sugar due to degradation of lignin and reduced the crystallinity of cellulose. The study showed that supplements could be used to improve the pretreatment process. The results were confirmed by scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy and thermogravimetric/differential thermogravimetric analysis of SSB.

All-in-one processing of heterogeneous human cell grafts for gene and cell therapy.

PubMed

Lukianova-Hleb, Ekaterina Y; Yvon, Eric S; Shpall, Elizabeth J; Lapotko, Dmitri O

2016-01-01

Current cell processing technologies for gene and cell therapies are often slow, expensive, labor intensive and are compromised by high cell losses and poor selectivity thus limiting the efficacy and availability of clinical cell therapies. We employ cell-specific on-demand mechanical intracellular impact from laser pulse-activated plasmonic nanobubbles (PNB) to process heterogeneous human cell grafts ex vivo with dual simultaneous functionality, the high cell type specificity, efficacy and processing rate for transfection of target CD3+ cells and elimination of subsets of unwanted CD25+ cells. The developed bulk flow PNB system selectively processed human cells at a rate of up to 100 million cell/minute, providing simultaneous transfection of CD3+ cells with the therapeutic gene (FKBP12(V36)-p30Caspase9) with the efficacy of 77% and viability 95% (versus 12 and 60%, respectively, for standard electroporation) and elimination of CD25+ cells with 99% efficacy. PNB flow technology can unite and replace several methodologies in an all-in-one universal ex vivo simultaneous procedure to precisely and rapidly prepare a cell graft for therapy. PNB's can process various cell systems including cord blood, stem cells, and bone marrow.

Patterning Method for Silver Nanoparticle Electrodes in Fully Solution-Processed Organic Thin-Film Transistors Using Selectively Treated Hydrophilic and Hydrophobic Surfaces

NASA Astrophysics Data System (ADS)

Fukuda, Kenjiro; Takeda, Yasunori; Kobayashi, Yu; Shimizu, Masahiro; Sekine, Tomohito; Kumaki, Daisuke; Kurihara, Masato; Sakamoto, Masatomi; Tokito, Shizuo

2013-05-01

Fully solution-processed organic thin-film transistor (OTFT) devices have been fabricated with simple patterning process at a relatively low process temperature of 100 °C. In the patterning process, a hydrophobic amorphous fluoropolymer material, which was used as the gate dielectric layer and the underlying base layer, was treated with an oxygen plasma to selectively change its surface wetting properties from hydrophobic to hydrophilic. Silver source and drain electrodes were successfully formed in the treated areas with highly uniform line widths and without residues between the electrodes. Nonuniformities in the thickness of the silver electrodes originating from the “coffee-ring” effect were suppressed by optimizing the blend of solvents used with the silver nanoparticles, such that the printed electrodes are appropriate for bottom-gate OTFT devices. A fully solution-processed OTFT device using a polymer semiconductor material (PB16TTT) exhibited good electrical performance with no hysteresis in its transfer characteristics and with good linearity in its output characteristics. A relatively high carrier mobility of 0.14 cm2 V-1 s-1 and an on/off ratio of 1×105 were obtained with the fabricated TFT device.

Effects of visual working memory on brain information processing of irrelevant auditory stimuli.

PubMed

Qu, Jiagui; Rizak, Joshua D; Zhao, Lun; Li, Minghong; Ma, Yuanye

2014-01-01

Selective attention has traditionally been viewed as a sensory processing modulator that promotes cognitive processing efficiency by favoring relevant stimuli while inhibiting irrelevant stimuli. However, the cross-modal processing of irrelevant information during working memory (WM) has been rarely investigated. In this study, the modulation of irrelevant auditory information by the brain during a visual WM task was investigated. The N100 auditory evoked potential (N100-AEP) following an auditory click was used to evaluate the selective attention to auditory stimulus during WM processing and at rest. N100-AEP amplitudes were found to be significantly affected in the left-prefrontal, mid-prefrontal, right-prefrontal, left-frontal, and mid-frontal regions while performing a high WM load task. In contrast, no significant differences were found between N100-AEP amplitudes in WM states and rest states under a low WM load task in all recorded brain regions. Furthermore, no differences were found between the time latencies of N100-AEP troughs in WM states and rest states while performing either the high or low WM load task. These findings suggested that the prefrontal cortex (PFC) may integrate information from different sensory channels to protect perceptual integrity during cognitive processing.

Method for extracting copper, silver and related metals

DOEpatents

Moyer, B.A.; McDowell, W.J.

1987-10-23

A process for selectively extracting precious metals such as silver and gold concurrent with copper extraction from aqueous solutions containing the same. The process utilizes tetrathiamacrocycles and high molecular weight organic acids that exhibit a synergistic relationship when complexing with certain metal ions thereby removing them from ore leach solutions.

College-Bound Digest.

ERIC Educational Resources Information Center

Who's Who among American High School Students, Lake Forest, IL.

The college admissions process and the college selection process are complex and much debated procedures which confront more than 50% of high school seniors in the United States. The purpose of this digest is to help students explore options available in choosing a suitable postsecondary education. For example the advantages of large or small…

Method for extracting copper, silver and related metals

DOEpatents

Moyer, Bruce A.; McDowell, W. J.

1990-01-01

A process for selectively extracting precious metals such as silver and gold concurrent with copper extraction from aqueous solutions containing the same. The process utilizes tetrathiamacrocycles and high molecular weight organic acids that exhibit a synergistic relationship when complexing with certain metal ions thereby removing them from ore leach solutions.

Literature review: Assessment of DWPF melter and melter off-gas system lifetime

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reigel, M. M.

2015-07-30

A glass melter for use in processing radioactive waste is a challenging environment for the materials of construction (MOC) resulting from a combination of high temperatures, chemical attack, and erosion/corrosion; therefore, highly engineered materials must be selected for this application. The focus of this report is to review the testing and evaluations used in the selection of the Defense Waste Processing Facility (DWPF), glass contact MOC specifically the Monofrax ® K-3 refractory and Inconel ® 690 alloy. The degradation or corrosion mechanisms of these materials during pilot scale testing and in-service operation were analyzed over a range of oxidizing andmore » reducing flowsheets; however, DWPF has primarily processed a reducing flowsheet (i.e., Fe 2+/ΣFe of 0.09 to 0.33) since the start of radioactive operations. This report also discusses the materials selection for the DWPF off-gas system and the corrosion evaluation of these materials during pilot scale testing and non-radioactive operations of DWPF Melter #1. Inspection of the off-gas components has not been performed during radioactive operations with the exception of maintenance because of plugging.« less

Literature review: Assessment of DWPF melter and melter off-gas system lifetime

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reigel, M.

2015-07-30

A glass melter for use in processing radioactive waste is a challenging environment for the materials of construction (MOC) resulting from a combination of high temperatures, chemical attack, and erosion/corrosion; therefore, highly engineered materials must be selected for this application. The focus of this report is to review the testing and evaluations used in the selection of the Defense Waste Processing Facility (DWPF), glass contact MOC specifically the Monofrax® K-3 refractory and Inconel® 690 alloy. The degradation or corrosion mechanisms of these materials during pilot scale testing and in-service operation were analyzed over a range of oxidizing and reducing flowsheets;more » however, DWPF has primarily processed a reducing flowsheet (i.e., Fe 2+/ΣFe of 0.09 to 0.33) since the start of radioactive operations. This report also discusses the materials selection for the DWPF off-gas system and the corrosion evaluation of these materials during pilot scale testing and non-radioactive operations of DWPF Melter #1. Inspection of the off-gas components has not been performed during radioactive operations with the exception of maintenance because of plugging.« less

Patterning of supported lipid bilayers and proteins using material selective nitrodopamine-mPEG.

PubMed

Spycher, Philipp R; Hall, Heike; Vogel, Viola; Reimhult, Erik

2015-01-01

We present a generic patterning process by which biomolecules in a passivated background are patterned directly from physiological buffer to microfabricated surfaces without the need for further processing. First, nitrodopamine-mPEG is self-assembled to selectively render TiO2 patterns non-fouling to biomolecule adsorption on hydrophilic and adhesive glass surfaces. After the controlled TiO2 passivation, the biomolecules can be directly adsorbed from solution in a single step creating large scale micropatterned and highly homogeneous arrays of biomolecules with very high pattern definition. We demonstrate the formation of fluid supported lipid bilayers (SLBs) down to the single μm-level limited only by the photolithographic process. Non-specific adsorption of lipid vesicles to the TiO2 background was found to be almost completely suppressed. The SLB patterns can be further selectively functionalized with retained mobility, which we demonstrate through biotin-streptavidin coupling. We envision this single step patterning approach to be very beneficial for membrane-based biosensors and for pattering of cells on a passivated background with complex, sub-cellular geometries; in each application the adherent areas have a tunable mobility of interaction sites controlled by the fluidity of the membrane.

Spatiotemporal dynamics of word retrieval in speech production revealed by cortical high-frequency band activity.

PubMed

Riès, Stephanie K; Dhillon, Rummit K; Clarke, Alex; King-Stephens, David; Laxer, Kenneth D; Weber, Peter B; Kuperman, Rachel A; Auguste, Kurtis I; Brunner, Peter; Schalk, Gerwin; Lin, Jack J; Parvizi, Josef; Crone, Nathan E; Dronkers, Nina F; Knight, Robert T

2017-06-06

Word retrieval is core to language production and relies on complementary processes: the rapid activation of lexical and conceptual representations and word selection, which chooses the correct word among semantically related competitors. Lexical and conceptual activation is measured by semantic priming. In contrast, word selection is indexed by semantic interference and is hampered in semantically homogeneous (HOM) contexts. We examined the spatiotemporal dynamics of these complementary processes in a picture naming task with blocks of semantically heterogeneous (HET) or HOM stimuli. We used electrocorticography data obtained from frontal and temporal cortices, permitting detailed spatiotemporal analysis of word retrieval processes. A semantic interference effect was observed with naming latencies longer in HOM versus HET blocks. Cortical response strength as indexed by high-frequency band (HFB) activity (70-150 Hz) amplitude revealed effects linked to lexical-semantic activation and word selection observed in widespread regions of the cortical mantle. Depending on the subsecond timing and cortical region, HFB indexed semantic interference (i.e., more activity in HOM than HET blocks) or semantic priming effects (i.e., more activity in HET than HOM blocks). These effects overlapped in time and space in the left posterior inferior temporal gyrus and the left prefrontal cortex. The data do not support a modular view of word retrieval in speech production but rather support substantial overlap of lexical-semantic activation and word selection mechanisms in the brain.

Selective chromogenic detection of thiol-containing biomolecules using carbonaceous nanospheres loaded with silver nanoparticles as carrier.

PubMed

Hu, Bo; Zhao, Yang; Zhu, Hai-Zhou; Yu, Shu-Hong

2011-04-26

Thiol-containing biomolecules show strong affinity with noble metal nanostructures and could not only stably protect them but also control the self-assembly process of these special nanostructures. A highly selective and sensitive chromogenic detection method has been designed for the low and high molecular weight thiol-containing biomolecules, including cysteine, glutathione, dithiothreitol, and bovine serum albumin, using a new type of carbonaceous nanospheres loaded with silver nanoparticles (Ag NPs) as carrier. This strategy relies upon the place-exchange process between the reporter dyes on the surface of Ag NPs and the thiol groups of thiol-containing biomolecules. The concentration of biomolecules can be determined by monitoring with the fluorescence intensity of reporter dyes dispersed in solution. This new chromogenic assay method could selectively detect these biomolecules in the presence of various other amino acids and monosaccharides and even sensitively detect the thiol-containing biomolecules with different molecular weight, even including proteins.

Spacecraft Electrical Connector Selection and Application Processes

NASA Technical Reports Server (NTRS)

Iannello, Chris; Davis, Mitchell I; Kichak, Robert A.; Slenski, George

2009-01-01

This assessment was initiated by the NASA Engineering & Safety Center (NESC) after a number of recent "high profile" connector problems, the most visible and publicized of these being the problem with the Space Shuttle's Engine Cut-Off System cryogenic feed-thru connector. The NESC commissioned a review of NASA's connector selection and application processes for space flight applications, including how lessons learned and past problem records are fed back into the processes to avoid recurring issues. Team members were primarily from the various NASA Centers and included connector and electrical parts specialists. The commissioned study was conducted on spacecraft connector selection and application processes at NASA Centers. The team also compared the NASA spacecraft connector selection and application process to the military process, identified recent high profile connector failures, and analyzed problem report data looking for trends and common occurrences. The team characterized NASA's connector problem experience into a list of top connector issues based on anecdotal evidence of a system's impact and commonality between Centers. These top issues are as follows, in no particular rank order: electrically shorted, bent and/or recessed contact pins, contact pin/socket contamination leading to electrically open or intermittencies, connector plating corrosion or corrosion of connector components, low or inadequate contact pin retention forces, contact crimp failures, unmated connectors and mis-wiring due to workmanship errors during installation or maintenance, loose connectors due to manufacturing defects such as wavy washer and worn bayonet retention, damaged connector elastomeric seals and cryogenic connector failure. A survey was also conducted of SAE Connector AE-8C1 committee members regarding their experience relative to the NASA concerns on connectors. The most common responses in order of occurrence were contact retention, plating issues, worn-out or damaged coupling mechanisms, bent pins, contact crimp barrel cracking and torn seals. In addition to these common themes, responses included issues with markings, dimensional errors on the build, contact/socket damage (handling), manufacturing defects and customer misapplication and mishandling. The NESC team concluded that considering the large quantity and wide variety of connectors successfully flown on human and robotic space applications, the number of failures is quite low. However, "high profile" failures with significant cost, schedule, safety, and/or mission success impacts continue to occur. It was also concluded that connector failures occur throughout a system's life-cycle with the majority of connector issues application related. A number of recommendations were identified for improving NASA connector selection processes and overall space connector reliability and performance.

Model for mapping settlements

DOEpatents

Vatsavai, Ranga Raju; Graesser, Jordan B.; Bhaduri, Budhendra L.

2016-07-05

A programmable media includes a graphical processing unit in communication with a memory element. The graphical processing unit is configured to detect one or more settlement regions from a high resolution remote sensed image based on the execution of programming code. The graphical processing unit identifies one or more settlements through the execution of the programming code that executes a multi-instance learning algorithm that models portions of the high resolution remote sensed image. The identification is based on spectral bands transmitted by a satellite and on selected designations of the image patches.

Autonomous selection of PDE inpainting techniques vs. exemplar inpainting techniques for void fill of high resolution digital surface models

NASA Astrophysics Data System (ADS)

Rahmes, Mark; Yates, J. Harlan; Allen, Josef DeVaughn; Kelley, Patrick

2007-04-01

High resolution Digital Surface Models (DSMs) may contain voids (missing data) due to the data collection process used to obtain the DSM, inclement weather conditions, low returns, system errors/malfunctions for various collection platforms, and other factors. DSM voids are also created during bare earth processing where culture and vegetation features have been extracted. The Harris LiteSite TM Toolkit handles these void regions in DSMs via two novel techniques. We use both partial differential equations (PDEs) and exemplar based inpainting techniques to accurately fill voids. The PDE technique has its origin in fluid dynamics and heat equations (a particular subset of partial differential equations). The exemplar technique has its origin in texture analysis and image processing. Each technique is optimally suited for different input conditions. The PDE technique works better where the area to be void filled does not have disproportionately high frequency data in the neighborhood of the boundary of the void. Conversely, the exemplar based technique is better suited for high frequency areas. Both are autonomous with respect to detecting and repairing void regions. We describe a cohesive autonomous solution that dynamically selects the best technique as each void is being repaired.

How Distinctive Processing Enhances Hits and Reduces False Alarms

PubMed Central

Hunt, R. Reed; Smith, Rebekah E.

2015-01-01

Distinctive processing is a concept designed to account for precision in memory, both correct responses and avoidance of errors. The principal question addressed in two experiments is how distinctive processing of studied material reduces false alarms to familiar distractors. Jacoby (Jacoby, Kelley, & McElree, 1999) has used the metaphors early selection and late correction to describe two different types of control processes. Early selection refers to limitations on access whereas late correction describes controlled monitoring of accessed information. The two types of processes are not mutually exclusive, and previous research has provided evidence for the operation of both. The data reported here extend previous work to a criterial recollection paradigm and to a recognition memory test. The results of both experiments show that variables that reduce false memory for highly familiar distracters continue to exert their effect under conditions of minimal post-access monitoring. Level of monitoring was reduced in the first experiment through test instructions and in the second experiment through speeded test responding. The results were consistent with the conclusion that both early selection and late correction operate to control accuracy in memory. PMID:26034343

Rule Based Category Learning in Patients with Parkinson’s Disease

PubMed Central

Price, Amanda; Filoteo, J. Vincent; Maddox, W. Todd

2009-01-01

Measures of explicit rule-based category learning are commonly used in neuropsychological evaluation of individuals with Parkinson’s disease (PD) and the pattern of PD performance on these measures tends to be highly varied. We review the neuropsychological literature to clarify the manner in which PD affects the component processes of rule-based category learning and work to identify and resolve discrepancies within this literature. In particular, we address the manner in which PD and its common treatments affect the processes of rule generation, maintenance, shifting and selection. We then integrate the neuropsychological research with relevant neuroimaging and computational modeling evidence to clarify the neurobiological impact of PD on each process. Current evidence indicates that neurochemical changes associated with PD primarily disrupt rule shifting, and may disturb feedback-mediated learning processes that guide rule selection. Although surgical and pharmacological therapies remediate this deficit, it appears that the same treatments may contribute to impaired rule generation, maintenance and selection processes. These data emphasize the importance of distinguishing between the impact of PD and its common treatments when considering the neuropsychological profile of the disease. PMID:19428385

Some fuzzy techniques for staff selection process: A survey

NASA Astrophysics Data System (ADS)

Md Saad, R.; Ahmad, M. Z.; Abu, M. S.; Jusoh, M. S.

2013-04-01

With high level of business competition, it is vital to have flexible staff that are able to adapt themselves with work circumstances. However, staff selection process is not an easy task to be solved, even when it is tackled in a simplified version containing only a single criterion and a homogeneous skill. When multiple criteria and various skills are involved, the problem becomes much more complicated. In adddition, there are some information that could not be measured precisely. This is patently obvious when dealing with opinions, thoughts, feelings, believes, etc. One possible tool to handle this issue is by using fuzzy set theory. Therefore, the objective of this paper is to review the existing fuzzy techniques for solving staff selection process. It classifies several existing research methods and identifies areas where there is a gap and need further research. Finally, this paper concludes by suggesting new ideas for future research based on the gaps identified.

Selective removal of cesium by ammonium molybdophosphate - polyacrylonitrile bead and membrane.

PubMed

Ding, Dahu; Zhang, Zhenya; Chen, Rongzhi; Cai, Tianming

2017-02-15

The selective removal of radionuclides with extremely low concentrations from environmental medium remains a big challenge. Ammonium molybdophosphate possess considerable selectivity towards cesium ion (Cs + ) due to the specific ion exchange between Cs + and NH 4 + . Ammonium molybdophosphate - polyacrylonitrile (AMP-PAN) membrane was successfully prepared for the first time in this study. Efficient removal of Cs + (95.7%, 94.1% and 91.3% of 1mgL -1 ) from solutions with high ionic strength (400mgL -1 of Na + , Ca 2+ or K + ) was achieved by AMP-PAN composite. Multilayer chemical adsorption process was testified through kinetic and isotherm studies. The estimated maximum adsorption capacities even reached 138.9±21.3mgg -1 . Specifically, the liquid film diffusion was identified as the rate-limiting step throughout the removal process. Finally, AMP-PAN membrane could eliminate Cs + from water effectively through the filtration adsorption process. Copyright © 2016 Elsevier B.V. All rights reserved.

Development of spent fuel reprocessing process based on selective sulfurization: Study on the Pu, Np and Am sulfurization

NASA Astrophysics Data System (ADS)

Kirishima, Akira; Amano, Yuuki; Nihei, Toshifumi; Mitsugashira, Toshiaki; Sato, Nobuaki

2010-03-01

For the recovery of fissile materials from spent nuclear fuel, we have proposed a novel reprocessing process based on selective sulfurization of fission products (FPs). The key concept of this process is utilization of unique chemical property of carbon disulfide (CS2), i.e., it works as a reductant for U3O8 but works as a sulfurizing agent for minor actinides and lanthanides. Sulfurized FPs and minor actinides (MA) are highly soluble to dilute nitric acid while UO2 and PuO2 are hardly soluble, therefore, FPs and MA can be removed from Uranium and Plutonium matrix by selective dissolution. As a feasibility study of this new concept, the sulfurization behaviours of U, Pu, Np, Am and Eu are investigated in this paper by the thermodynamical calculation, phase analysis of chemical analogue elements and tracer experiments.

Transparent conductor-embedding nanocones for selective emitters: optical and electrical improvements of Si solar cells

PubMed Central

Kim, Joondong; Yun, Ju-Hyung; Kim, Hyunyub; Cho, Yunae; Park, Hyeong-Ho; Kumar, M. Melvin David; Yi, Junsin; Anderson, Wayne A.; Kim, Dong-Wook

2015-01-01

Periodical nanocone-arrays were employed in an emitter region for high efficient Si solar cells. Conventional wet-etching process was performed to form the nanocone-arrays for a large area, which spontaneously provides the graded doping features for a selective emitter. This enables to lower the electrical contact resistance and enhances the carrier collection due to the high electric field distribution through a nanocone. Optically, the convex-shaped nanocones efficiently reduce light-reflection and the incident light is effectively focused into Si via nanocone structure, resulting in an extremely improved the carrier collection performances. This nanocone-arrayed selective emitter simultaneously satisfies optical and electrical improvement. We report the record high efficiency of 16.3% for the periodically nanoscale patterned emitter Si solar cell. PMID:25787933

Transparent conductor-embedding nanocones for selective emitters: optical and electrical improvements of Si solar cells.

PubMed

Kim, Joondong; Yun, Ju-Hyung; Kim, Hyunyub; Cho, Yunae; Park, Hyeong-Ho; Kumar, M Melvin David; Yi, Junsin; Anderson, Wayne A; Kim, Dong-Wook

2015-03-19

Periodical nanocone-arrays were employed in an emitter region for high efficient Si solar cells. Conventional wet-etching process was performed to form the nanocone-arrays for a large area, which spontaneously provides the graded doping features for a selective emitter. This enables to lower the electrical contact resistance and enhances the carrier collection due to the high electric field distribution through a nanocone. Optically, the convex-shaped nanocones efficiently reduce light-reflection and the incident light is effectively focused into Si via nanocone structure, resulting in an extremely improved the carrier collection performances. This nanocone-arrayed selective emitter simultaneously satisfies optical and electrical improvement. We report the record high efficiency of 16.3% for the periodically nanoscale patterned emitter Si solar cell.

Continuous recovery of valine in a model mixture of amino acids and salt from Corynebacterium bacteria fermentation using a simulated moving bed chromatography.

PubMed

Park, Chanhun; Nam, Hee-Geun; Jo, Se-Hee; Wang, Nien-Hwa Linda; Mun, Sungyong

2016-02-26

The economical efficiency of valine production in related industries is largely affected by the performance of a valine separation process, in which valine is to be separated from leucine, alanine, and ammonium sulfate. Such separation is currently handled by a batch-mode hybrid process based on ion-exchange and crystallization schemes. To make a substantial improvement in the economical efficiency of an industrial valine production, such a batch-mode process based on two different separation schemes needs to be converted into a continuous-mode separation process based on a single separation scheme. To address this issue, a simulated moving bed (SMB) technology was applied in this study to the development of a continuous-mode valine-separation chromatographic process with uniformity in adsorbent and liquid phases. It was first found that a Chromalite-PCG600C resin could be eligible for the adsorbent of such process, particularly in an industrial scale. The intrinsic parameters of each component on the Chromalite-PCG600C adsorbent were determined and then utilized in selecting a proper set of configurations for SMB units, columns, and ports, under which the SMB operating parameters were optimized with a genetic algorithm. Finally, the optimized SMB based on the selected configurations was tested experimentally, which confirmed its effectiveness in continuous separation of valine from leucine, alanine, ammonium sulfate with high purity, high yield, high throughput, and high valine product concentration. It is thus expected that the developed SMB process in this study will be able to serve as one of the trustworthy ways of improving the economical efficiency of an industrial valine production process. Copyright © 2016 Elsevier B.V. All rights reserved.

Vitamin B1-catalyzed acetoin formation from acetaldehyde: a key step for upgrading bioethanol to bulk C₄ chemicals.

PubMed

Lu, Ting; Li, Xiukai; Gu, Liuqun; Zhang, Yugen

2014-09-01

The production of bulk chemicals and fuels from renewable biobased feedstocks is of significant importance for the sustainability of human society. The production of ethanol from biomass has dramatically increased and bioethanol also holds considerable potential as a versatile building block for the chemical industry. Herein, we report a highly selective process for the conversion of ethanol to C4 bulk chemicals, such as 2,3-butanediol and butene, via a vitamin B1 (thiamine)-derived N-heterocyclic carbene (NHC)-catalyzed acetoin condensation as the key step to assemble two C2 acetaldehydes into a C4 product. The environmentally benign and cheap natural catalyst vitamin B1 demonstrates high selectivity (99%), high efficiency (97% yield), and high tolerance toward ethanol and water impurities in the acetoin reaction. The results enable a novel and efficient process for ethanol upgrading. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

High Voltage Insulation Technology

NASA Astrophysics Data System (ADS)

Scherb, V.; Rogalla, K.; Gollor, M.

2008-09-01

In preparation of new Electronic Power Conditioners (EPC's) for Travelling Wave Tub Amplifiers (TWTA's) on telecom satellites a study for the development of new high voltage insulation technology is performed. The initiative is mandatory to allow compact designs and to enable higher operating voltages. In a first task a market analysis was performed, comparing different materials with respect to their properties and processes. A hierarchy of selection criteria was established and finally five material candidates (4 Epoxy resins and 1 Polyurethane resin) were selected to be further investigated in the test program. Samples for the test program were designed to represent core elements of an EPC, the high voltage transformer and Printed Circuit Boards of the high voltage section. All five materials were assessed in the practical work flow of the potting process and electrical, mechanical, thermal and lifetime testing was performed. Although the lifetime tests results were overlayed by a larges scatter, finally two candidates have been identified for use in a subsequent qualification program. This activity forms part of element 5 of the ESA ARTES Programme.

ToxCast Data Generation: Chemical Workflow

EPA Pesticide Factsheets

This page describes the process EPA follows to select chemicals, procure chemicals, register chemicals, conduct a quality review of the chemicals, and prepare the chemicals for high-throughput screening.

Selective Deoxygenation of Biomass‐Derived Bio‐oils within Hydrogen‐Modest Environments: A Review and New Insights

PubMed Central

Rogers, Kyle A.

2016-01-01

Abstract Research development of processes for refining bio‐oils is becoming increasingly popular. One issue that these processes possess is their high requirement for H2 gas. In response, researchers must develop catalysts that perform deoxygenation while minimizing H2 consumption—selective deoxygenation. Unlike traditional deoxygenation processes, selective deoxygenation reactions and catalysts represent an information gap that, prior to this publication, has yet to be reviewed. This review addresses the gap by providing both a summary of recent research developments and insight into future developments of new catalytic materials. Bifunctional catalysts containing a combination of oxophilicity and an active metal phase appear to be the most beneficial for selective deoxygenation processes in a H2‐modest environment. It is important that catalysts have a supply of disassociated hydrogen, because without such, activity and stability will suffer. The authors recommend to maximize the use of internally available hydrogen in bio‐fuel, which may be the only viable approach for deoxygenation if external H2 gas is limited. This would be possible through the development of catalysts that promote both the water–gas‐shift and deoxygenation reactions. PMID:27385663

Processes for producing low cost, high efficiency silicon solar cells

DOEpatents

Rohatgi, A.; Doshi, P.; Tate, J.K.; Mejia, J.; Chen, Z.

1998-06-16

Processes which utilize rapid thermal processing (RTP) are provided for inexpensively producing high efficiency silicon solar cells. The RTP processes preserve minority carrier bulk lifetime {tau} and permit selective adjustment of the depth of the diffused regions, including emitter and back surface field (bsf), within the silicon substrate. In a first RTP process, an RTP step is utilized to simultaneously diffuse phosphorus and aluminum into the front and back surfaces, respectively, of a silicon substrate. Moreover, an in situ controlled cooling procedure preserves the carrier bulk lifetime {tau} and permits selective adjustment of the depth of the diffused regions. In a second RTP process, both simultaneous diffusion of the phosphorus and aluminum as well as annealing of the front and back contacts are accomplished during the RTP step. In a third RTP process, the RTP step accomplishes simultaneous diffusion of the phosphorus and aluminum, annealing of the contacts, and annealing of a double-layer antireflection/passivation coating SiN/SiO{sub x}. In a fourth RTP process, the process of applying front and back contacts is broken up into two separate respective steps, which enhances the efficiency of the cells, at a slight time expense. In a fifth RTP process, a second RTP step is utilized to fire and adhere the screen printed or evaporated contacts to the structure. 28 figs.

Emerging late adolescent friendship networks and Big Five personality traits: a social network approach.

PubMed

Selfhout, Maarten; Burk, William; Branje, Susan; Denissen, Jaap; van Aken, Marcel; Meeus, Wim

2010-04-01

The current study focuses on the emergence of friendship networks among just-acquainted individuals, investigating the effects of Big Five personality traits on friendship selection processes. Sociometric nominations and self-ratings on personality traits were gathered from 205 late adolescents (mean age=19 years) at 5 time points during the first year of university. SIENA, a novel multilevel statistical procedure for social network analysis, was used to examine effects of Big Five traits on friendship selection. Results indicated that friendship networks between just-acquainted individuals became increasingly more cohesive within the first 3 months and then stabilized. Whereas individuals high on Extraversion tended to select more friends than those low on this trait, individuals high on Agreeableness tended to be selected more as friends. In addition, individuals tended to select friends with similar levels of Agreeableness, Extraversion, and Openness.

A structured multi-stakeholder learning process for Sustainable Land Management.

PubMed

Schwilch, Gudrun; Bachmann, Felicitas; Valente, Sandra; Coelho, Celeste; Moreira, Jorge; Laouina, Abdellah; Chaker, Miloud; Aderghal, Mohamed; Santos, Patricia; Reed, Mark S

2012-09-30

There are many, often competing, options for Sustainable Land Management (SLM). Each must be assessed - and sometimes negotiated - prior to implementation. Participatory, multi-stakeholder approaches to identification and selection of SLM options are increasingly popular, often motivated by social learning and empowerment goals. Yet there are few practical tools for facilitating processes in which land managers may share, select, and decide on the most appropriate SLM options. The research presented here aims to close the gap between the theory and the practice of stakeholder participation/learning in SLM decision-making processes. The paper describes a three-part participatory methodology for selecting SLM options that was tested in 14 desertification-prone study sites within the EU-DESIRE project. Cross-site analysis and in-depth evaluation of the Moroccan and Portuguese sites were used to evaluate how well the proposed process facilitated stakeholder learning and selection of appropriate SLM options for local implementation. The structured nature of the process - starting with SLM goal setting - was found to facilitate mutual understanding and collaboration between stakeholders. The deliberation process led to a high degree of consensus over the outcome and, though not an initial aim, it fostered social learning in many cases. This solution-oriented methodology is applicable in a wide range of contexts and may be implemented with limited time and resources. Copyright © 2012 Elsevier Ltd. All rights reserved.

Preparation of High Purity, High Molecular-Weight Chitin from Ionic Liquids for Use as an Adsorbate for the Extraction of Uranium from Seawater

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rogers, Robin

Ensuring a domestic supply of uranium is a key issue facing the wider implementation of nuclear power. Uranium is mostly mined in Kazakhstan, Australia, and Canada, and there are few high-grade uranium reserves left worldwide. Therefore, one of the most appealing potential sources of uranium is the vast quantity dissolved in the oceans (estimated to be 4.4 billion tons worldwide). There have been research efforts centered on finding a means to extract uranium from seawater for decades, but so far none have resulted in an economically viable product, due in part to the fact that the materials that have beenmore » successfully demonstrated to date are too costly (in terms of money and energy) to produce on the necessary scale. Ionic Liquids (salts which melt below 100{degrees}C) can completely dissolve raw crustacean shells, leading to recovery of a high purity, high molecular weight chitin powder and to fibers and films which can be spun directly from the extract solution suggesting that continuous processing might be feasible. The work proposed here will utilize the unprecedented control this makes possible over the chitin fiber a) to prepare electrospun nanofibers of very high surface area and in specific architectures, b) to modify the fiber surfaces chemically with selective extractant capacity, and c) to demonstrate their utility in the direct extraction and recovery of uranium from seawater. This approach will 1) provide direct extraction of chitin from shellfish waste thus saving energy over the current industrial process for obtaining chitin; 2) allow continuous processing of nanofibers for very high surface area fibers in an economical operation; 3) provide a unique high molecular weight chitin not available from the current industrial process, leading to stronger, more durable fibers; and 4) allow easy chemical modification of the large surface areas of the fibers for appending uranyl selective functionality providing selectivity and ease of stripping. The resulting sorbent should prove economically feasible, as well as providing an overall net energy gain.« less

Can parental monitoring and peer management reduce the selection or influence of delinquent peers? Testing the question using a dynamic social network approach.

PubMed

Tilton-Weaver, Lauree C; Burk, William J; Kerr, Margaret; Stattin, Håkan

2013-11-01

We tested whether parents can reduce affiliation with delinquent peers through 3 forms of peer management: soliciting information, monitoring rules, and communicating disapproval of peers. We examined whether peer management interrupted 2 peer processes: selection and influence of delinquent peers. Adolescents' feelings of being overcontrolled by parents were examined as an additional moderator of delinquent selection and influence. Using network data from a community sample (N = 1,730), we tested whether selection and influence processes varied across early, middle, and late adolescent cohorts. Selection and influence of delinquent peers were evident in all 3 cohorts and did not differ in strength. Parental monitoring rules reduced the selection of delinquent peers in the oldest cohort. A similar effect was found in the early adolescent cohort, but only for adolescents who did not feel overcontrolled by parents. Monitoring rules increased the likelihood of selecting a delinquent friend among those who felt overcontrolled. The effectiveness of communicating disapproval was also mixed: in the middle adolescent network, communicating disapproval increased the likelihood of an adolescent selecting a delinquent friend. Among late adolescents, high levels of communicating disapproval were effective, reducing the influence of delinquent peers for adolescents reporting higher rates of delinquency. For those who reported lower levels of delinquency, high levels of communicating disapproval increased the influence of delinquent peers. The results of this study suggest that the effectiveness of monitoring and peer management depend on the type of behavior, the timing of its use, and whether adolescents feel overcontrolled by parents.

Spatial Selection and Local Adaptation Jointly Shape Life-History Evolution during Range Expansion.

PubMed

Van Petegem, Katrien H P; Boeye, Jeroen; Stoks, Robby; Bonte, Dries

2016-11-01

In the context of climate change and species invasions, range shifts increasingly gain attention because the rates at which they occur in the Anthropocene induce rapid changes in biological assemblages. During range shifts, species experience multiple selection pressures. For poleward expansions in particular, it is difficult to interpret observed evolutionary dynamics because of the joint action of evolutionary processes related to spatial selection and to adaptation toward local climatic conditions. To disentangle the effects of these two processes, we integrated stochastic modeling and data from a common garden experiment, using the spider mite Tetranychus urticae as a model species. By linking the empirical data with those derived form a highly parameterized individual-based model, we infer that both spatial selection and local adaptation contributed to the observed latitudinal life-history divergence. Spatial selection best described variation in dispersal behavior, while variation in development was best explained by adaptation to the local climate. Divergence in life-history traits in species shifting poleward could consequently be jointly determined by contemporary evolutionary dynamics resulting from adaptation to the environmental gradient and from spatial selection. The integration of modeling with common garden experiments provides a powerful tool to study the contribution of these evolutionary processes on life-history evolution during range expansion.

Controlled catalytic and thermal sequential pyrolysis and hydrolysis of mixed polymer waste streams to sequentially recover monomers or other high value products

DOEpatents

Evans, Robert J.; Chum, Helena L.

1994-01-01

A process of using fast pyrolysis in a carrier gas to convert a plastic waste feedstream having a mixed polymeric composition in a manner such that pyrolysis of a given polymer to its high value monomeric constituent occurs prior to pyrolysis of other plastic components therein comprising: selecting a first temperature program range to cause pyrolysis of said given polymer to its high value monomeric constituent prior to a temperature range that causes pyrolysis of other plastic components; selecting a catalyst and support for treating said feed streams with said catalyst to effect acid or base catalyzed reaction pathways to maximize yield or enhance separation of said high value monomeric constituent in said temperature program range; differentially heating said feed stream at a heat rate within the first temperature program range to provide differential pyrolysis for selective recovery of optimum quantities of the high value monomeric constituent prior to pyrolysis of other plastic components; separating the high value monomeric constituents, selecting a second higher temperature range to cause pyrolysis of a different high value monomeric constituent of said plastic waste and differentially heating the feedstream at the higher temperature program range to cause pyrolysis of the different high value monomeric constituent; and separating the different high value monomeric constituent.

Controlled catalytic and thermal sequential pyrolysis and hydrolysis of mixed polymer waste streams to sequentially recover monomers or other high value products

DOEpatents

Evans, Robert J.; Chum, Helena L.

1994-01-01

A process of using fast pyrolysis in a carrier gas to convert a plastic waste feedstream having a mixed polymeric composition in a manner such that pyrolysis of a given polymer to its high value monomeric constituent occurs prior to pyrolysis of other plastic components therein comprising: selecting a first temperature program range to cause pyrolysis of said given polymer to its high value monomeric constituent prior to a temperature range that causes pyrolysis of other plastic components; selecting a catalyst and support for treating said feed streams with said catalyst to effect acid or base catalyzed reaction pathways to maximize yield or enhance separation of said high value monomeric constituent in said temperature program range; differentially heating said feed stream at a heat rate within the first temperature program range to provide differential pyrolysis for selective recovery of optimum quantities of the high value monomeric constituent prior to pyrolysis of other plastic components; separating the high value monomeric constituents; selecting a second higher temperature range to cause pyrolysis of a different high value monomeric constituent of said plastic waste and differentially heating the feedstream at the higher temperature program range to cause pyrolysis of the different high value monomeric constituent; and separating the different high value monomeric constituent.

Controlled catalytic and thermal sequential pyrolysis and hydrolysis of mixed polymer waste streams to sequentially recover monomers or other high value products

DOEpatents

Evans, Robert J.; Chum, Helena L.

1993-01-01

A process of using fast pyrolysis in a carrier gas to convert a plastic waste feedstream having a mixed polymeric composition in a manner such that pyrolysis of a given polymer to its high value monomeric constituent occurs prior to pyrolysis of other plastic components therein comprising: selecting a first temperature program range to cause pyrolysis of said given polymer to its high value monomeric constituent prior to a temperature range that causes pyrolysis of other plastic components; selecting a catalyst and support for treating said feed streams with said catalyst to effect acid or base catalyzed reaction pathways to maximize yield or enhance separation of said high value monomeric constituent in said temperature program range; differentially heating said feed stream at a heat rate within the first temperature program range to provide differential pyrolysis for selective recovery of optimum quantities of the high value monomeric constituent prior to pyrolysis of other plastic components; separating the high value monomeric constituents; selecting a second higher temperature range to cause pyrolysis of a different high value monomeric constituent of said plastic waste and differentially heating the feedstream at the higher temperature program range to cause pyrolysis of the different high value monomeric constituent; and separating the different high value monomeric constituent.

Diazepam dose-dependently increases or decreases implicit priming of alcohol associations in problem drinkers.

PubMed

Zack, Martin; Poulos, Constantine X; Woodford, Tracy M

2006-01-01

Words denoting negative affect (NEG) have been found to prime alcohol-related words (ALC) on semantic priming tasks, and this effect is tied to severity of addiction. Previous research suggested that high doses of benzodiazepines may dampen NEG-ALC priming. The present study tested this possibility and the role of motivation for alcohol in this process. A placebo-controlled, double blind, between-within, counterbalanced design was employed. Two groups of male problem drinkers (n = 6/group) received a high (15-mg) or low (5-mg) dose of diazepam versus placebo on two identical test sessions. A lexical decision task assessed priming. Under placebo, significant NEG-->ALC priming emerged in each group. High-dose diazepam selectively reversed this effect, while low-dose selectively enhanced it. Correlations between NEG-->ALC priming and desire for alcohol provided further support that semantic priming of ALC concepts reflects a motivational process. The bi-directional effects found here parallel the effects of high- versus low-dose benzodiazepines on alcohol self-administration in animals. High-dose diazepam reduces prime-induced activation of ALC concepts in problem drinkers. Low-dose diazepam facilitates this process, and cross-priming of motivation for alcohol appears to explain this effect. Neurochemical modulation of the alcohol memory network may contribute to the motivational effects of benzodiazepines in problem drinkers.

[Comparative study of cone-beam CT and spiral CT in measuring the length of styloid process].

PubMed

Song, Y S; Liu, L F

2018-06-19

Objective: To compare the difference of measuring the length of styloid process between spiral CT with high resolution and cone-beam CT(CBCT). Methods: Five specimens (including 5 pairs of styloid processes) were selected randomly from the Anatomy Laboratory of Otolaryngology Department, all the specimens underwent spiral CT with high resolution and cone-beam CT retrospectively.With the original DICOM data, the styloid processes were shown in one plate by multiple plate reconstruction technique, and later the length of styloid processes of each specimen were measured separately by software NNT Viewer (to CBCT) or Osrix (to spiral CT with high resolution). Results: The length of styloid processes measured by CBCT and spiral CT was (26.8±5.5) mm and (27.1±5.4) mm respectively, and there was no statistical difference between the two groups. Conclusion: In respect of measuring the length of styloid process, the CBCT has the same value in clinical practice comparing to spiral CT with high resolution.

High-temperature experimental and thermodynamic modelling research on the pyrometallurgical processing of copper

NASA Astrophysics Data System (ADS)

Hidayat, Taufiq; Shishin, Denis; Decterov, Sergei A.; Hayes, Peter C.; Jak, Evgueni

2017-01-01

Uncertainty in the metal price and competition between producers mean that the daily operation of a smelter needs to target high recovery of valuable elements at low operating cost. Options for the improvement of the plant operation can be examined and decision making can be informed based on accurate information from laboratory experimentation coupled with predictions using advanced thermodynamic models. Integrated high-temperature experimental and thermodynamic modelling research on phase equilibria and thermodynamics of copper-containing systems have been undertaken at the Pyrometallurgy Innovation Centre (PYROSEARCH). The experimental phase equilibria studies involve high-temperature equilibration, rapid quenching and direct measurement of phase compositions using electron probe X-ray microanalysis (EPMA). The thermodynamic modelling deals with the development of accurate thermodynamic database built through critical evaluation of experimental data, selection of solution models, and optimization of models parameters. The database covers the Al-Ca-Cu-Fe-Mg-O-S-Si chemical system. The gas, slag, matte, liquid and solid metal phases, spinel solid solution as well as numerous solid oxide and sulphide phases are included. The database works within the FactSage software environment. Examples of phase equilibria data and thermodynamic models of selected systems, as well as possible implementation of the research outcomes to selected copper making processes are presented.

Imprint-coating synthesis of selective functionalized ordered mesoporous sorbents for separation and sensors

DOEpatents

Dai, Sheng; Burleigh, Mark C.; Shin, Yongsoon

2001-01-01

The present invention relates generally to mesoporous sorbent materials having high capacity, high selectivity, fast kinetics, and molecular recognition capability. The invention also relates to a process for preparing these mesoporous substrates through molecular imprinting techniques which differ from convention techniques in that a template molecule is bound to one end of bifunctional ligands to form a complex prior to binding of the bifunctional ligands to the substrate. The present invention also relates to methods of using the mesoporous sorbent materials, for example, in the separation of toxic metals from process effluents, paints, and other samples; detection of target molecules, such as amino acids, drugs, herbicides, fertilizers, and TNT, in samples; separation and/or detection of substances using chromatography; imaging agents; sensors; coatings; and composites.

A Review of Biorefinery Separations for Bioproduct Production via Thermocatalytic Processing.

PubMed

Nguyen, Hannah; DeJaco, Robert F; Mittal, Nitish; Siepmann, J Ilja; Tsapatsis, Michael; Snyder, Mark A; Fan, Wei; Saha, Basudeb; Vlachos, Dionisios G

2017-06-07

With technological advancement of thermocatalytic processes for valorizing renewable biomass carbon, development of effective separation technologies for selective recovery of bioproducts from complex reaction media and their purification becomes essential. The high thermal sensitivity of biomass intermediates and their low volatility and high reactivity, along with the use of dilute solutions, make the bioproducts separations energy intensive and expensive. Novel separation techniques, including solvent extraction in biphasic systems and reactive adsorption using zeolite and carbon sorbents, membranes, and chromatography, have been developed. In parallel with experimental efforts, multiscale simulations have been reported for predicting solvent selection and adsorption separation. We discuss various separations that are potentially valuable to future biorefineries and the factors controlling separation performance. Particular emphasis is given to current gaps and opportunities for future development.

Norepinephrine ignites local hot spots of neuronal excitation: How arousal amplifies selectivity in perception and memory

PubMed Central

Mather, Mara; Clewett, David; Sakaki, Michiko; Harley, Carolyn W.

2018-01-01

Long Abstract Existing brain-based emotion-cognition theories fail to explain arousal’s ability to both enhance and impair cognitive processing. In the Glutamate Amplifies Noradrenergic Effects (GANE) model outlined in this paper, we propose that arousal-induced norepinephrine (NE) released from the locus coeruleus (LC) biases perception and memory in favor of salient, high priority representations at the expense of lower priority representations. This increase in gain under phasic arousal occurs via synaptic self-regulation of NE based on glutamate levels. When the LC is phasically active, elevated levels of glutamate at the site of prioritized representations increase local NE release, creating “NE hot spots.” At these local hot spots, glutamate and NE release are mutually enhancing and amplify activation of prioritized representations. This excitatory effect contrasts with widespread NE suppression of weaker representations via lateral and auto-inhibitory processes. On a broader scale, hot spots increase oscillatory synchronization across neural ensembles transmitting high priority information. Furthermore, key brain structures that detect or pre-determine stimulus priority interact with phasic NE release to preferentially route such information through large-scale functional brain networks. A surge of NE before, during or after encoding enhances synaptic plasticity at sites of high glutamate activity, triggering local protein synthesis processes that enhance selective memory consolidation. Together, these noradrenergic mechanisms increase perceptual and memory selectivity under arousal. Beyond explaining discrepancies in the emotion-cognition literature, GANE reconciles and extends previous influential theories of LC neuromodulation by highlighting how NE can produce such different outcomes in processing based on priority. PMID:26126507

Rapid and simple preparation of rhodamine 6G loaded HY zeolite for highly selective nitrite detection

NASA Astrophysics Data System (ADS)

Viboonratanasri, Duangkamon; Pabchanda, Suwat; Prompinit, Panida

2018-05-01

In this study, a simple, rapid and relatively less toxic method for rhodamine 6G dye adsorption on hydrogen-form Y-type zeolite for highly selective nitrite detection was demonstrated. The adsorption behavior was described by Langmuir isotherm and the adsorption process reached the equilibrium promptly within a minute. The developed test papers characterized by fluorescence technique display high sensing performance with wide working range (0.04-20.0 mg L-1) and high selectivity. The test papers show good reproducibility with relative standard deviation (RSD) of 7% for five replicated determinations of 3 mg L-1 of nitrite. The nitrite concentration determined by using the test paper was in the same range as using ion chromatography within a 95% confidence level. The test papers offer advantages in terms of low cost and practical usage enabling them to be a promising candidate for nitrite sensor in environmental samples, food, and fertilizers.

Residency Program Directors' Interview Methods and Satisfaction With Resident Selection Across Multiple Specialties.

PubMed

VanOrder, Tonya; Robbins, Wayne; Zemper, Eric

2017-04-01

Competition for postdoctoral training positions is at an all-time high, and residency program directors continue to have little direction when it comes to structuring an effective interview process. To examine whether a relationship existed between interview methods used and program director satisfaction with resident selection decisions and whether programs that used methods designed to assess candidate personal characteristics were more satisfied with their decisions. Residency directors from the Statewide Campus System at the Michigan State University College of Osteopathic Medicine were invited to complete a 20-item survey regarding their recent interview methods and proportion of resident selections later regretted. Data analyses examined relationships between interview methods used, frequency of personal characteristics evaluated, and subsequent satisfaction with selected residents. Of the 186 program director surveys distributed, 83 (44.6%) were returned, representing 11 clinical specialty areas. In total, 69 responses (83.1%) were from programs accredited by the American Osteopathic Association only, and 14 (16.9%) were from programs accredited dually by the American Osteopathic Association and Accreditation Council for Graduate Medical Education. The most frequent interview method reported was faculty or peer resident interview. No statistically significant correlational relationships were found between type of interview methods used and subsequent satisfaction with selected residents, either within or across clinical specialties. Although program directors rated ethical behavior/honesty as the most highly prioritized characteristic in residents, 27 (32.5%) reported using a specific interview method to assess this trait. Program directors reported later regrets concerning nearly 1 of every 12 resident selection decisions. The perceived success of an osteopathic residency program's interview process does not appear to be related to methods used and is not distinctively different from that of programs dually accredited. The findings suggest that it may not be realistic to aim for standardization of a common set of best interview methods or ideal personal characteristics for all programs. Each residency program's optimal interview process is likely unique, more dependent on analyzing why some resident selections are regretted and developing an interview process designed to assess for specific desirable and unwanted characteristics.

Thread-Like CMOS Logic Circuits Enabled by Reel-Processed Single-Walled Carbon Nanotube Transistors via Selective Doping.

PubMed

Heo, Jae Sang; Kim, Taehoon; Ban, Seok-Gyu; Kim, Daesik; Lee, Jun Ho; Jur, Jesse S; Kim, Myung-Gil; Kim, Yong-Hoon; Hong, Yongtaek; Park, Sung Kyu

2017-08-01

The realization of large-area electronics with full integration of 1D thread-like devices may open up a new era for ultraflexible and human adaptable electronic systems because of their potential advantages in demonstrating scalable complex circuitry by a simply integrated weaving technology. More importantly, the thread-like fiber electronic devices can be achieved using a simple reel-to-reel process, which is strongly required for low-cost and scalable manufacturing technology. Here, high-performance reel-processed complementary metal-oxide-semiconductor (CMOS) integrated circuits are reported on 1D fiber substrates by using selectively chemical-doped single-walled carbon nanotube (SWCNT) transistors. With the introduction of selective n-type doping and a nonrelief photochemical patterning process, p- and n-type SWCNT transistors are successfully implemented on cylindrical fiber substrates under air ambient, enabling high-performance and reliable thread-like CMOS inverter circuits. In addition, it is noteworthy that the optimized reel-coating process can facilitate improvement in the arrangement of SWCNTs, building uniformly well-aligned SWCNT channels, and enhancement of the electrical performance of the devices. The p- and n-type SWCNT transistors exhibit field-effect mobility of 4.03 and 2.15 cm 2 V -1 s -1 , respectively, with relatively narrow distribution. Moreover, the SWCNT CMOS inverter circuits demonstrate a gain of 6.76 and relatively good dynamic operation at a supply voltage of 5.0 V. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

De novo transcriptome assembly and positive selection analysis of an individual deep-sea fish.

PubMed

Lan, Yi; Sun, Jin; Xu, Ting; Chen, Chong; Tian, Renmao; Qiu, Jian-Wen; Qian, Pei-Yuan

2018-05-24

High hydrostatic pressure and low temperatures make the deep sea a harsh environment for life forms. Actin organization and microtubules assembly, which are essential for intracellular transport and cell motility, can be disrupted by high hydrostatic pressure. High hydrostatic pressure can also damage DNA. Nucleic acids exposed to low temperatures can form secondary structures that hinder genetic information processing. To study how deep-sea creatures adapt to such a hostile environment, one of the most straightforward ways is to sequence and compare their genes with those of their shallow-water relatives. We captured an individual of the fish species Aldrovandia affinis, which is a typical deep-sea inhabitant, from the Okinawa Trough at a depth of 1550 m using a remotely operated vehicle (ROV). We sequenced its transcriptome and analyzed its molecular adaptation. We obtained 27,633 protein coding sequences using an Illumina platform and compared them with those of several shallow-water fish species. Analysis of 4918 single-copy orthologs identified 138 positively selected genes in A. affinis, including genes involved in microtubule regulation. Particularly, functional domains related to cold shock as well as DNA repair are exposed to positive selection pressure in both deep-sea fish and hadal amphipod. Overall, we have identified a set of positively selected genes related to cytoskeleton structures, DNA repair and genetic information processing, which shed light on molecular adaptation to the deep sea. These results suggest that amino acid substitutions of these positively selected genes may contribute crucially to the adaptation of deep-sea animals. Additionally, we provide a high-quality transcriptome of a deep-sea fish for future deep-sea studies.

Factors influencing equipment selection in electron beam processing

NASA Astrophysics Data System (ADS)

Barnard, J. W.

2003-08-01

During the eighties and nineties accelerator manufacturers dramatically increased the beam power available for high-energy equipment. This effort was directed primarily at meeting the demands of the sterilization industry. During this era, the perception that bigger (higher power, higher energy) was always better prevailed since the operating and capital costs of accelerators did not increase with power and energy as fast as the throughput. High power was needed to maintain per unit costs low for treatment. This philosophy runs counter to certain present-day realities of the sterilization business as well as conditions influencing accelerator selection in other electron beam applications. Recent experience in machine selection is described and factors affecting choice are presented.

Selection of components for the IDEALHY preferred cycle for the large scale liquefaction of hydrogen

DOE Office of Scientific and Technical Information (OSTI.GOV)

Quack, H.; Seemann, I.; Klaus, M.

2014-01-29

In a future energy scenario, in which storage and transport of liquid hydrogen in large quantities will be used, the efficiency of the liquefaction of hydrogen will be of utmost importance. The goal of the IDEALHY working party is to identify the most promising process for a 50 t/d plant and to select the components, with which such a process can be realized. In the first stage the team has compared several processes, which have been proposed or realized in the past. Based on this information a process has been selected, which is thermodynamically most promising and for which itmore » could be assumed that good components already exist or can be developed in the foreseeable future. Main features of the selected process are the compression of the feed stream to a relatively high pressure level, o-p conversion inside plate-fin heat exchangers and expansion turbines in the supercritical region. Precooling to a temperature between 150 and 100 K will be obtained from a mixed refrigerant cycle similar to the systems used successfully in natural gas liquefaction plants. The final cooling will be produced by two Brayton cycles, both having several expansion turbines in series. The selected overall process has still a number of parameters, which can be varied. The optimum, i.e. the final choice will depend mainly on the quality of the available components. Key components are the expansion turbines of the two Brayton cycles and the main recycle compressor, which may be common to both Brayton cycles. A six-stage turbo-compressor with intercooling between the stages is expected to be the optimum choice here. Each stage may consist of several wheels in series. To make such a high efficient and cost-effective compressor feasible, one has to choose a refrigerant, which has a higher molecular weight than helium. The present preferred choice is a mixture of helium and neon with a molecular weight of about 8 kg/kmol. Such an expensive refrigerant requires that the whole refrigeration loop is extremely tight.« less

Area-Selective Atomic Layer Deposition of Metal Oxides on Noble Metals through Catalytic Oxygen Activation

PubMed Central

2017-01-01

Area-selective atomic layer deposition (ALD) is envisioned to play a key role in next-generation semiconductor processing and can also provide new opportunities in the field of catalysis. In this work, we developed an approach for the area-selective deposition of metal oxides on noble metals. Using O2 gas as co-reactant, area-selective ALD has been achieved by relying on the catalytic dissociation of the oxygen molecules on the noble metal surface, while no deposition takes place on inert surfaces that do not dissociate oxygen (i.e., SiO2, Al2O3, Au). The process is demonstrated for selective deposition of iron oxide and nickel oxide on platinum and iridium substrates. Characterization by in situ spectroscopic ellipsometry, transmission electron microscopy, scanning Auger electron spectroscopy, and X-ray photoelectron spectroscopy confirms a very high degree of selectivity, with a constant ALD growth rate on the catalytic metal substrates and no deposition on inert substrates, even after 300 ALD cycles. We demonstrate the area-selective ALD approach on planar and patterned substrates and use it to prepare Pt/Fe2O3 core/shell nanoparticles. Finally, the approach is proposed to be extendable beyond the materials presented here, specifically to other metal oxide ALD processes for which the precursor requires a strong oxidizing agent for growth. PMID:29503508

Multistate and phase change selection in constitutional multivalent systems.

PubMed

Barboiu, Mihail

2012-01-01

Molecular architectures and materials can be constitutionally self-sorted in the presence of different biomolecular targets or external physical stimuli or chemical effectors, thus responding to an external selection pressure. The high selectivity and specificity of different bioreceptors or self-correlated internal interactions may be used to describe the complex constitutional behaviors through multistate component selection from a dynamic library. The self-selection may result in the dynamic amplification of self-optimized architectures during the phase change process. The sol-gel resolution of dynamic molecular/supramolecular libraries leads to higher self-organized constitutional hybrid materials, in which organic (supramolecular)/inorganic domains are reversibily connected.

Effects of binge drinking and hangover on response selection sub-processes-a study using EEG and drift diffusion modeling.

PubMed

Stock, Ann-Kathrin; Hoffmann, Sven; Beste, Christian

2017-09-01

Effects of binge drinking on cognitive control and response selection are increasingly recognized in research on alcohol (ethanol) effects. Yet, little is known about how those processes are modulated by hangover effects. Given that acute intoxication and hangover seem to be characterized by partly divergent effects and mechanisms, further research on this topic is needed. In the current study, we hence investigated this with a special focus on potentially differential effects of alcohol intoxication and subsequent hangover on sub-processes involved in the decision to select a response. We do so combining drift diffusion modeling of behavioral data with neurophysiological (EEG) data. Opposed to common sense, the results do not show an impairment of all assessed measures. Instead, they show specific effects of high dose alcohol intoxication and hangover on selective drift diffusion model and EEG parameters (as compared to a sober state). While the acute intoxication induced by binge-drinking decreased the drift rate, it was increased by the subsequent hangover, indicating more efficient information accumulation during hangover. Further, the non-decisional processes of information encoding decreased with intoxication, but not during hangover. These effects were reflected in modulations of the N2, P1 and N1 event-related potentials, which reflect conflict monitoring, perceptual gating and attentional selection processes, respectively. As regards the functional neuroanatomical architecture, the anterior cingulate cortex (ACC) as well as occipital networks seem to be modulated. Even though alcohol is known to have broad neurobiological effects, its effects on cognitive processes are rather specific. © 2016 Society for the Study of Addiction.

Academic Attitudes and Achievement in Students of Urban Public Single-Sex and Mixed-Sex High Schools

ERIC Educational Resources Information Center

Else-Quest, Nicole M.; Peterca, Oana

2015-01-01

Publicly funded single-sex schooling (SSS) has proliferated in recent years and is touted as a remedy to gaps in academic attitudes and achievement, particularly for low-income students of color. Research on SSS is rife with limitations, stemming from selective admissions processes, selection effects related to socioeconomic status, a lack of…

A fluorogenic molecular nanoprobe with an engineered internal environment for sensitive and selective detection of biological hydrogen sulfide.

PubMed

Kim, Myung; Seo, Young Hun; Kim, Youngsun; Heo, Jeongyun; Jang, Woo-Dong; Sim, Sang Jun; Kim, Sehoon

2017-02-14

A nanoreactor approach based on the amphiphilic assembly of various molecules offers a chance to finely engineer the internal reaction medium to enable highly selective and sensitive detection of H 2 S in biological media, being useful for microscopic imaging of cellular processes and in vitro diagnostics with blood samples.

Quality transformation of dissolved organic carbon during water transit through lakes: contrasting controls by photochemical and biological processes

NASA Astrophysics Data System (ADS)

Berggren, Martin; Klaus, Marcus; Panneer Selvam, Balathandayuthabani; Ström, Lena; Laudon, Hjalmar; Jansson, Mats; Karlsson, Jan

2018-01-01

Dissolved organic carbon (DOC) may be removed, transformed, or added during water transit through lakes, resulting in changes in DOC composition and pigmentation (color). However, the process-based understanding of these changes is incomplete, especially for headwater lakes. We hypothesized that because heterotrophic bacteria preferentially consume noncolored DOC, while photochemical processing removes colored fractions, the overall changes in DOC color upon water passage through a lake depend on the relative importance of these two processes, accordingly. To test this hypothesis we combined laboratory experiments with field studies in nine boreal lakes, assessing both the relative importance of different DOC decay processes (biological or photochemical) and the loss of color during water transit time (WTT) through the lakes. We found that influence from photo-decay dominated changes in DOC quality in the epilimnia of relatively clear headwater lakes, resulting in systematic and selective net losses of colored DOC. However, in highly pigmented brown-water lakes (absorbance at 420 nm > 7 m-1) biological processes dominated, and there was no systematic relationship between color loss and WTT. Moreover, in situ data and dark experiments supported our hypothesis on the selective microbial removal of nonpigmented DOC, mainly of low molecular weight, leading to persistent water color in these highly colored lakes. Our study shows that brown headwater lakes may not conform to the commonly reported pattern of the selective removal of colored constituents in freshwaters, as DOC can show a sustained degree of pigmentation upon transit through these lakes.

Improved targeted immunization strategies based on two rounds of selection

NASA Astrophysics Data System (ADS)

Xia, Ling-Ling; Song, Yu-Rong; Li, Chan-Chan; Jiang, Guo-Ping

2018-04-01

In the case of high degree targeted immunization where the number of vaccine is limited, when more than one node associated with the same degree meets the requirement of high degree centrality, how can we choose a certain number of nodes from those nodes, so that the number of immunized nodes will not exceed the limit? In this paper, we introduce a new idea derived from the selection process of second-round exam to solve this problem and then propose three improved targeted immunization strategies. In these proposed strategies, the immunized nodes are selected through two rounds of selection, where we increase the quotas of first-round selection according the evaluation criterion of degree centrality and then consider another characteristic parameter of node, such as node's clustering coefficient, betweenness and closeness, to help choose targeted nodes in the second-round selection. To validate the effectiveness of the proposed strategies, we compare them with the degree immunizations including the high degree targeted and the high degree adaptive immunizations using two metrics: the size of the largest connected component of immunized network and the number of infected nodes. Simulation results demonstrate that the proposed strategies based on two rounds of sorting are effective for heterogeneous networks and their immunization effects are better than that of the degree immunizations.

Material selection indices for design of surgical instruments with long tubular shafts.

PubMed

Nelson, Carl A

2013-02-01

In any medical device design process, material selection plays an important role. For devices which sustain mechanical loading, strength and stiffness requirements can be significant drivers of the design. This paper examines the specific case of minimally invasive surgical instruments, including robotic instruments, having long, tubular shafts. Material properties-based selection indices are derived for achieving high performance of these devices in terms of strength and stiffness, and the use of these indices for informing the medical device design problem is illustrated.

Selective Conversion of Biorefinery Lignin into Dicarboxylic Acids

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ma, Ruoshui; Guo, Mond; Zhang, Xiao

The emerging biomass-to-biofuel conversion industry has created an urgent need for identifying new applications for biorefinery lignin. This paper demonstrates a new route to producing dicarboxylic acids from biorefinery lignin through chalcopyrite-catalyzed oxidation in a highly selective process. Up to 95 % selectivity towards stable dicarboxylic acids was obtained for several types of biorefinery lignin and model compounds under mild, environmentally friendly reaction conditions. The findings from this study paved a new avenue to biorefinery lignin conversions and applications.

Investigating the Prospective Sense of Agency: Effects of Processing Fluency, Stimulus Ambiguity, and Response Conflict.

PubMed

Sidarus, Nura; Vuorre, Matti; Metcalfe, Janet; Haggard, Patrick

2017-01-01

How do we know how much control we have over our environment? The sense of agency refers to the feeling that we are in control of our actions, and that, through them, we can control our external environment. Thus, agency clearly involves matching intentions, actions, and outcomes. The present studies investigated the possibility that processes of action selection, i.e., choosing what action to make, contribute to the sense of agency. Since selection of action necessarily precedes execution of action, such effects must be prospective. In contrast, most literature on sense of agency has focussed on the retrospective computation whether an outcome fits the action performed or intended. This hypothesis was tested in an ecologically rich, dynamic task based on a computer game. Across three experiments, we manipulated three different aspects of action selection processing: visual processing fluency, categorization ambiguity, and response conflict. Additionally, we measured the relative contributions of prospective, action selection-based cues, and retrospective, outcome-based cues to the sense of agency. Manipulations of action selection were orthogonally combined with discrepancy of visual feedback of action. Fluency of action selection had a small but reliable effect on the sense of agency. Additionally, as expected, sense of agency was strongly reduced when visual feedback was discrepant with the action performed. The effects of discrepant feedback were larger than the effects of action selection fluency, and sometimes suppressed them. The sense of agency is highly sensitive to disruptions of action-outcome relations. However, when motor control is successful, and action-outcome relations are as predicted, fluency or dysfluency of action selection provides an important prospective cue to the sense of agency.

Investigating the Prospective Sense of Agency: Effects of Processing Fluency, Stimulus Ambiguity, and Response Conflict

PubMed Central

Sidarus, Nura; Vuorre, Matti; Metcalfe, Janet; Haggard, Patrick

2017-01-01

How do we know how much control we have over our environment? The sense of agency refers to the feeling that we are in control of our actions, and that, through them, we can control our external environment. Thus, agency clearly involves matching intentions, actions, and outcomes. The present studies investigated the possibility that processes of action selection, i.e., choosing what action to make, contribute to the sense of agency. Since selection of action necessarily precedes execution of action, such effects must be prospective. In contrast, most literature on sense of agency has focussed on the retrospective computation whether an outcome fits the action performed or intended. This hypothesis was tested in an ecologically rich, dynamic task based on a computer game. Across three experiments, we manipulated three different aspects of action selection processing: visual processing fluency, categorization ambiguity, and response conflict. Additionally, we measured the relative contributions of prospective, action selection-based cues, and retrospective, outcome-based cues to the sense of agency. Manipulations of action selection were orthogonally combined with discrepancy of visual feedback of action. Fluency of action selection had a small but reliable effect on the sense of agency. Additionally, as expected, sense of agency was strongly reduced when visual feedback was discrepant with the action performed. The effects of discrepant feedback were larger than the effects of action selection fluency, and sometimes suppressed them. The sense of agency is highly sensitive to disruptions of action-outcome relations. However, when motor control is successful, and action-outcome relations are as predicted, fluency or dysfluency of action selection provides an important prospective cue to the sense of agency. PMID:28450839

Specific cognitive-neurophysiological processes predict impulsivity in the childhood attention-deficit/hyperactivity disorder combined subtype.

PubMed

Bluschke, A; Roessner, V; Beste, C

2016-04-01

Attention-deficit/hyperactivity disorder (ADHD) is one of the most prevalent neuropsychiatric disorders in childhood. Besides inattention and hyperactivity, impulsivity is the third core symptom leading to diverse and serious problems. However, the neuronal mechanisms underlying impulsivity in ADHD are still not fully understood. This is all the more the case when patients with the ADHD combined subtype (ADHD-C) are considered who are characterized by both symptoms of inattention and hyperactivity/impulsivity. Combining high-density electroencephalography (EEG) recordings with source localization analyses, we examined what information processing stages are dysfunctional in ADHD-C (n = 20) compared with controls (n = 18). Patients with ADHD-C made more impulsive errors in a Go/No-go task than healthy controls. Neurophysiologically, different subprocesses from perceptual gating to attentional selection, resource allocation and response selection processes are altered in this patient group. Perceptual gating, stimulus-driven attention selection and resource allocation processes were more pronounced in ADHD-C, are related to activation differences in parieto-occipital networks and suggest attentional filtering deficits. However, only response selection processes, associated with medial prefrontal networks, predicted impulsive errors in ADHD-C. Although the clinical picture of ADHD-C is complex and a multitude of processing steps are altered, only a subset of processes seems to directly modulate impulsive behaviour. The present findings improve the understanding of mechanisms underlying impulsivity in patients with ADHD-C and might help to refine treatment algorithms focusing on impulsivity.

Advances in medical image computing.

PubMed

Tolxdorff, T; Deserno, T M; Handels, H; Meinzer, H-P

2009-01-01

Medical image computing has become a key technology in high-tech applications in medicine and an ubiquitous part of modern imaging systems and the related processes of clinical diagnosis and intervention. Over the past years significant progress has been made in the field, both on methodological and on application level. Despite this progress there are still big challenges to meet in order to establish image processing routinely in health care. In this issue, selected contributions of the German Conference on Medical Image Processing (BVM) are assembled to present latest advances in the field of medical image computing. The winners of scientific awards of the German Conference on Medical Image Processing (BVM) 2008 were invited to submit a manuscript on their latest developments and results for possible publication in Methods of Information in Medicine. Finally, seven excellent papers were selected to describe important aspects of recent advances in the field of medical image processing. The selected papers give an impression of the breadth and heterogeneity of new developments. New methods for improved image segmentation, non-linear image registration and modeling of organs are presented together with applications of image analysis methods in different medical disciplines. Furthermore, state-of-the-art tools and techniques to support the development and evaluation of medical image processing systems in practice are described. The selected articles describe different aspects of the intense development in medical image computing. The image processing methods presented enable new insights into the patient's image data and have the future potential to improve medical diagnostics and patient treatment.

Using multiple classifiers for predicting the risk of endovascular aortic aneurysm repair re-intervention through hybrid feature selection.

PubMed

Attallah, Omneya; Karthikesalingam, Alan; Holt, Peter Je; Thompson, Matthew M; Sayers, Rob; Bown, Matthew J; Choke, Eddie C; Ma, Xianghong

2017-11-01

Feature selection is essential in medical area; however, its process becomes complicated with the presence of censoring which is the unique character of survival analysis. Most survival feature selection methods are based on Cox's proportional hazard model, though machine learning classifiers are preferred. They are less employed in survival analysis due to censoring which prevents them from directly being used to survival data. Among the few work that employed machine learning classifiers, partial logistic artificial neural network with auto-relevance determination is a well-known method that deals with censoring and perform feature selection for survival data. However, it depends on data replication to handle censoring which leads to unbalanced and biased prediction results especially in highly censored data. Other methods cannot deal with high censoring. Therefore, in this article, a new hybrid feature selection method is proposed which presents a solution to high level censoring. It combines support vector machine, neural network, and K-nearest neighbor classifiers using simple majority voting and a new weighted majority voting method based on survival metric to construct a multiple classifier system. The new hybrid feature selection process uses multiple classifier system as a wrapper method and merges it with iterated feature ranking filter method to further reduce features. Two endovascular aortic repair datasets containing 91% censored patients collected from two centers were used to construct a multicenter study to evaluate the performance of the proposed approach. The results showed the proposed technique outperformed individual classifiers and variable selection methods based on Cox's model such as Akaike and Bayesian information criterions and least absolute shrinkage and selector operator in p values of the log-rank test, sensitivity, and concordance index. This indicates that the proposed classifier is more powerful in correctly predicting the risk of re-intervention enabling doctor in selecting patients' future follow-up plan.

Distinct Escape Pathway by Hepatitis C Virus Genotype 1a from a Dominant CD8+ T Cell Response by Selection of Altered Epitope Processing.

PubMed

Walker, Andreas; Skibbe, Kathrin; Steinmann, Eike; Pfaender, Stephanie; Kuntzen, Thomas; Megger, Dominik A; Groten, Svenja; Sitek, Barbara; Lauer, Georg M; Kim, Arthur Y; Pietschmann, Thomas; Allen, Todd M; Timm, Joerg

2016-01-01

Antiviral CD8(+) T cells are a key component of the adaptive immune response against HCV, but their impact on viral control is influenced by preexisting viral variants in important target epitopes and the development of viral escape mutations. Immunodominant epitopes highly conserved across genotypes therefore are attractive for T cell based prophylactic vaccines. Here, we characterized the CD8(+) T cell response against the highly conserved HLA-B*51-restricted epitope IPFYGKAI1373-1380 located in the helicase domain of NS3 in people who inject drugs (PWID) exposed predominantly to HCV genotypes 1a and 3a. Despite this epitope being conserved in both genotypes, the corresponding CD8(+) T cell response was detected only in PWID infected with genotype 3a and HCV-RNA negative PWID, but not in PWID infected with genotype 1a. In genotype 3a, the detection of strong CD8(+) T cell responses was associated with epitope variants in the autologous virus consistent with immune escape. Analysis of viral sequences from multiple cohorts confirmed HLA-B*51-associated escape mutations inside the epitope in genotype 3a, but not in genotype 1a. Here, a distinct substitution in the N-terminal flanking region located 5 residues upstream of the epitope (S1368P; P = 0.00002) was selected in HLA-B*51-positive individuals. Functional assays revealed that the S1368P substitution impaired recognition of target cells presenting the endogenously processed epitope. The results highlight that, despite an epitope being highly conserved between two genotypes, there are major differences in the selected viral escape pathways and the corresponding T cell responses. HCV is able to evolutionary adapt to CD8(+) T cell immune pressure in multiple ways. Beyond selection of mutations inside targeted epitopes, this study demonstrates that HCV inhibits epitope processing by modification of the epitope flanking region under T cell immune pressure. Selection of a substitution five amino acids upstream of the epitope underlines that efficient antigen presentation strongly depends on its larger sequence context and that blocking of the multistep process of antigen processing by mutation is exploited also by HCV. The pathways to mutational escape of HCV are to some extent predictable but are distinct in different genotypes. Importantly, the selected escape pathway of HCV may have consequences for the destiny of antigen-specific CD8(+) T cells. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Mediators of effects of a selective family-focused violence prevention approach for middle school students.

PubMed

2012-02-01

This study examined how parenting and family characteristics targeted in a selective prevention program mediated effects on key youth proximal outcomes related to violence perpetration. The selective intervention was evaluated within the context of a multi-site trial involving random assignment of 37 schools to four conditions: a universal intervention composed of a student social-cognitive curriculum and teacher training, a selective family-focused intervention with a subset of high-risk students, a condition combining these two interventions, and a no-intervention control condition. Two cohorts of sixth-grade students (total N = 1,062) exhibiting high levels of aggression and social influence were the sample for this study. Analyses of pre-post change compared to controls using intent-to-treat analyses found no significant effects. However, estimates incorporating participation of those assigned to the intervention and predicted participation among those not assigned revealed significant positive effects on student aggression, use of aggressive strategies for conflict management, and parental estimation of student's valuing of achievement. Findings also indicated intervention effects on two targeted family processes: discipline practices and family cohesion. Mediation analyses found evidence that change in these processes mediated effects on some outcomes, notably aggressive behavior and valuing of school achievement. Results support the notion that changing parenting practices and the quality of family relationships can prevent the escalation in aggression and maintain positive school engagement for high-risk youth.

A Comparative Investigation of the Combined Effects of Pre-Processing, Wavelength Selection, and Regression Methods on Near-Infrared Calibration Model Performance.

PubMed

Wan, Jian; Chen, Yi-Chieh; Morris, A Julian; Thennadil, Suresh N

2017-07-01

Near-infrared (NIR) spectroscopy is being widely used in various fields ranging from pharmaceutics to the food industry for analyzing chemical and physical properties of the substances concerned. Its advantages over other analytical techniques include available physical interpretation of spectral data, nondestructive nature and high speed of measurements, and little or no need for sample preparation. The successful application of NIR spectroscopy relies on three main aspects: pre-processing of spectral data to eliminate nonlinear variations due to temperature, light scattering effects and many others, selection of those wavelengths that contribute useful information, and identification of suitable calibration models using linear/nonlinear regression . Several methods have been developed for each of these three aspects and many comparative studies of different methods exist for an individual aspect or some combinations. However, there is still a lack of comparative studies for the interactions among these three aspects, which can shed light on what role each aspect plays in the calibration and how to combine various methods of each aspect together to obtain the best calibration model. This paper aims to provide such a comparative study based on four benchmark data sets using three typical pre-processing methods, namely, orthogonal signal correction (OSC), extended multiplicative signal correction (EMSC) and optical path-length estimation and correction (OPLEC); two existing wavelength selection methods, namely, stepwise forward selection (SFS) and genetic algorithm optimization combined with partial least squares regression for spectral data (GAPLSSP); four popular regression methods, namely, partial least squares (PLS), least absolute shrinkage and selection operator (LASSO), least squares support vector machine (LS-SVM), and Gaussian process regression (GPR). The comparative study indicates that, in general, pre-processing of spectral data can play a significant role in the calibration while wavelength selection plays a marginal role and the combination of certain pre-processing, wavelength selection, and nonlinear regression methods can achieve superior performance over traditional linear regression-based calibration.

Sexual segregation in North American elk: the role of density dependence

PubMed Central

Stewart, Kelley M; Walsh, Danielle R; Kie, John G; Dick, Brian L; Bowyer, R Terry

2015-01-01

We investigated how density-dependent processes and subsequent variation in nutritional condition of individuals influenced both timing and duration of sexual segregation and selection of resources. During 1999–2001, we experimentally created two population densities of North American elk (Cervus elaphus), a high-density population at 20 elk/km2, and a low-density population at 4 elk/km2 to test hypotheses relative to timing and duration of sexual segregation and variation in selection of resources. We used multi-response permutation procedures to investigate patterns of sexual segregation, and resource selection functions to document differences in selection of resources by individuals in high- and low-density populations during sexual segregation and aggregation. The duration of sexual segregation was 2 months longer in the high-density population and likely was influenced by individuals in poorer nutritional condition, which corresponded with later conception and parturition, than at low density. Males and females in the high-density population overlapped in selection of resources to a greater extent than in the low-density population, probably resulting from density-dependent effects of increased intraspecific competition and lower availability of resources. PMID:25691992

Low-Energy Water Recovery from Subsurface Brines

DOE Office of Scientific and Technical Information (OSTI.GOV)

Choi, Young Chul; Kim, Gyu Dong; Hendren, Zachary

A novel non-aqueous phase solvent (NAS) desalination process was proposed and developed in this research project. The NAS desalination process uses less energy than thermal processes, doesn’t require any additional chemicals for precipitation, and can be utilized to treat high TDS brine. In this project, our experimental work determined that water solubility changes and selective absorption are the key characteristics of NAS technology for successful desalination. Three NAS desalination mechanisms were investigated: (1) CO2 switchable, (2) high-temp absorption to low-temp desorption (thermally switchable), and (3) low-temp absorption to high-temp desorption (thermally switchable). Among these mechanisms, thermally switchable (low-temp absorption tomore » high-temp desorption) showed the highest water recovery and relatively high salt rejection. A test procedure for semi-continuous, bench scale NAS desalination process was also developed and used to assess performance under a range of conditions.« less

Using SAS functions and high-resolution isotope data to unravel travel time distributions in headwater catchments

NASA Astrophysics Data System (ADS)

Benettin, Paolo; Soulsby, Chris; Birkel, Christian; Tetzlaff, Doerthe; Botter, Gianluca; Rinaldo, Andrea

2017-03-01

We use high-resolution tracer data from an experimental site to test theoretical approaches that integrate catchment-scale flow and transport processes in a unified framework centered on selective age sampling by streamflow and evapotranspiration fluxes. Transport processes operating at the catchment scale are reflected in the evolving residence time distribution of the catchment water storage and in the age selection operated by out-fluxes. Such processes are described here through StorAge Selection (SAS) functions parameterized as power laws of the normalized rank storage. Such functions are computed through appropriate solution of the master equation defining formally the evolution of residence and travel times. By representing the way in which catchment storage generates outflows composed by water of different ages, the main mechanism regulating the tracer composition of runoff is clearly identified and detailed comparison with empirical data sets are possible. Properly calibrated numerical tools provide simulations that convincingly reproduce complex measured signals of daily deuterium content in stream waters during wet and dry periods. Results for the catchment under consideration are consistent with other recent studies indicating a tendency for natural catchments to preferentially release younger available water. The study shows that power law SAS functions prove a powerful tool to explain catchment-scale transport processes that also has potential in less intensively monitored sites.

Highly efficient conversion of plant oil to bio-aviation fuel and valuable chemicals by combination of enzymatic transesterification, olefin cross-metathesis, and hydrotreating.

PubMed

Wang, Meng; Chen, Mojin; Fang, Yunming; Tan, Tianwei

2018-01-01

The production of fuels and chemicals from renewable resources is increasingly important due to the environmental concern and depletion of fossil fuel. Despite the fast technical development in the production of aviation fuels, there are still several shortcomings such as a high cost of raw materials, a low yield of aviation fuels, and poor process techno-economic consideration. In recent years, olefin metathesis has become a powerful and versatile tool for generating new carbon-carbon bonds. The cross-metathesis reaction, one kind of metathesis reaction, has a high potential to efficiently convert plant oil into valuable chemicals, such as α-olefin and bio-aviation fuel by combining with a hydrotreatment process. In this research, an efficient, four-step conversion of plant oil into bio-aviation fuel and valuable chemicals was developed by the combination of enzymatic transesterification, olefin cross-metathesis, and hydrotreating. Firstly, plant oil including oil with poor properties was esterified to fatty acid methyl esters by an enzyme-catalyzed process. Secondly, the fatty acid methyl esters were partially hydrotreated catalytically to transform poly-unsaturated fatty acid such as linoleic acid into oleic acid. The olefin cross-metathesis then transformed the oleic acid methyl ester (OAME) into 1-decene and 1-decenoic acid methyl ester (DAME). The catalysts used in this process were prepared/selected in function of the catalytic reaction and the reaction conditions were optimized. The carbon efficiency analysis of the new process illustrated that it was more economically feasible than the traditional hydrotreatment process. A highly efficient conversion process of plant oil into bio-aviation fuel and valuable chemicals by the combination of enzymatic transesterification, olefin cross-metathesis, and hydrotreatment with prepared and selected catalysts was designed. The reaction conditions were optimized. Plant oil was transformed into bio-aviation fuel and a high value α-olefin product with high carbon utilization.

Marker-assisted selection in plant breeding for salinity tolerance.

PubMed

Ashraf, M; Akram, N A; Mehboob-Ur-Rahman; Foolad, M R

2012-01-01

Marker-assisted selection (MAS) is the process of using morphological, biochemical, or DNA markers as indirect selection criteria for selecting agriculturally important traits in crop breeding. This process is used to improve the effectiveness or efficiency of selection for the traits of interest in breeding programs. The significance of MAS as a tool for crop improvement has been extensively investigated in different crop -species and for different traits. The use of MAS for manipulating simple/qualitative traits is straightforward and has been well reported. However, MAS for the improvement of complex/polygenic traits, including plant tolerance/resistance to abiotic stresses, is more complicated, although its usefulness has been recognized. With the recent advances in marker technology, including high-throughput genotyping of plants, together with the development of nested association mapping populations, it is expected that the utility of MAS for breeding for stress tolerance traits will increase. In this chapter, we describe the basic procedure for using MAS in crop breeding for salt tolerance.

Auditory Attentional Control and Selection during Cocktail Party Listening

PubMed Central

Hill, Kevin T.

2010-01-01

In realistic auditory environments, people rely on both attentional control and attentional selection to extract intelligible signals from a cluttered background. We used functional magnetic resonance imaging to examine auditory attention to natural speech under such high processing-load conditions. Participants attended to a single talker in a group of 3, identified by the target talker's pitch or spatial location. A catch-trial design allowed us to distinguish activity due to top-down control of attention versus attentional selection of bottom-up information in both the spatial and spectral (pitch) feature domains. For attentional control, we found a left-dominant fronto-parietal network with a bias toward spatial processing in dorsal precentral sulcus and superior parietal lobule, and a bias toward pitch in inferior frontal gyrus. During selection of the talker, attention modulated activity in left intraparietal sulcus when using talker location and in bilateral but right-dominant superior temporal sulcus when using talker pitch. We argue that these networks represent the sources and targets of selective attention in rich auditory environments. PMID:19574393

One-pot process combining transesterification and selective hydrogenation for biodiesel production from starting material of high degree of unsaturation.

PubMed

Yang, Ru; Su, Mengxing; Li, Min; Zhang, Jianchun; Hao, Xinmin; Zhang, Hua

2010-08-01

A one-pot process combining transesterification and selective hydrogenation was established to produce biodiesel from hemp (Cannabis sativa L.) seed oil which is eliminated as a potential feedstock by a specification of iodine value (IV; 120 g I(2)/100g maximum) contained in EN 14214. A series of alkaline earth metal oxides and alkaline earth metal supported copper oxide were prepared and tested as catalysts. SrO supported 10 wt.% CuO showed the superior catalytic activity for transesterification with a biodiesel yield of 96% and hydrogenation with a reduced iodine value of 113 and also exhibited a promising selectivity for eliminating methyl linolenate and increasing methyl oleate without rising methyl stearate in the selective hydrogenation. The fuel properties of the selective hydrogenated methyl esters are within biodiesel specifications. Furthermore, cetane numbers and iodine values were well correlated with the compositions of the hydrogenated methyl esters according to degrees of unsaturation. (c) 2010 Elsevier Ltd. All rights reserved.

Critical ligand binding reagent preparation/selection: when specificity depends on reagents.

PubMed

Rup, Bonita; O'Hara, Denise

2007-05-11

Throughout the life cycle of biopharmaceutical products, bioanalytical support is provided using ligand binding assays to measure the drug product for pharmacokinetic, pharmacodynamic, and immunogenicity studies. The specificity and selectivity of these ligand binding assays are highly dependent on the ligand binding reagents. Thus the selection, characterization, and management processes for ligand binding reagents are crucial to successful assay development and application. This report describes process considerations for selection and characterization of ligand binding reagents that are integral parts of the different phases of assay development. Changes in expression, purification, modification, and storage of the ligand binding reagents may have a profound effect on the ligand binding assay performance. Thus long-term management of the critical ligand binding assay reagents is addressed including suggested characterization criteria that allow ligand binding reagents to be used in as consistent a manner as possible. Examples of challenges related to the selection, modification, and characterization of ligand binding reagents are included.

Defect Detection in Arc-Welding Processes by Means of the Line-to-Continuum Method and Feature Selection.

PubMed

Garcia-Allende, P Beatriz; Mirapeix, Jesus; Conde, Olga M; Cobo, Adolfo; Lopez-Higuera, Jose M

2009-01-01

Plasma optical spectroscopy is widely employed in on-line welding diagnostics. The determination of the plasma electron temperature, which is typically selected as the output monitoring parameter, implies the identification of the atomic emission lines. As a consequence, additional processing stages are required with a direct impact on the real time performance of the technique. The line-to-continuum method is a feasible alternative spectroscopic approach and it is particularly interesting in terms of its computational efficiency. However, the monitoring signal highly depends on the chosen emission line. In this paper, a feature selection methodology is proposed to solve the uncertainty regarding the selection of the optimum spectral band, which allows the employment of the line-to-continuum method for on-line welding diagnostics. Field test results have been conducted to demonstrate the feasibility of the solution.

Mutation-selection equilibrium in games with multiple strategies.

PubMed

Antal, Tibor; Traulsen, Arne; Ohtsuki, Hisashi; Tarnita, Corina E; Nowak, Martin A

2009-06-21

In evolutionary games the fitness of individuals is not constant but depends on the relative abundance of the various strategies in the population. Here we study general games among n strategies in populations of large but finite size. We explore stochastic evolutionary dynamics under weak selection, but for any mutation rate. We analyze the frequency dependent Moran process in well-mixed populations, but almost identical results are found for the Wright-Fisher and Pairwise Comparison processes. Surprisingly simple conditions specify whether a strategy is more abundant on average than 1/n, or than another strategy, in the mutation-selection equilibrium. We find one condition that holds for low mutation rate and another condition that holds for high mutation rate. A linear combination of these two conditions holds for any mutation rate. Our results allow a complete characterization of nxn games in the limit of weak selection.

Ultrathin graphene oxide-based hollow fiber membranes with brush-like CO2-philic agent for highly efficient CO2 capture.

PubMed

Zhou, Fanglei; Tien, Huynh Ngoc; Xu, Weiwei L; Chen, Jung-Tsai; Liu, Qiuli; Hicks, Ethan; Fathizadeh, Mahdi; Li, Shiguang; Yu, Miao

2017-12-13

Among the current CO 2 capture technologies, membrane gas separation has many inherent advantages over other conventional techniques. However, fabricating gas separation membranes with both high CO 2 permeance and high CO 2 /N 2 selectivity, especially under wet conditions, is a challenge. In this study, sub-20-nm thick, layered graphene oxide (GO)-based hollow fiber membranes with grafted, brush-like CO 2 -philic agent alternating between GO layers are prepared by a facile coating process for highly efficient CO 2 /N 2 separation under wet conditions. Piperazine, as an effective CO 2 -philic agent, is introduced as a carrier-brush into the GO nanochannels with chemical bonding. The membrane exhibits excellent separation performance under simulated flue gas conditions with CO 2 permeance of 1,020 GPU and CO 2 /N 2 selectivity as high as 680, demonstrating its potential for CO 2 capture from flue gas. We expect this GO-based membrane structure combined with the facile coating process to facilitate the development of ultrathin GO-based membranes for CO 2 capture.

Ultra-high-performance supercritical fluid chromatography with quadrupole-time-of-flight mass spectrometry (UHPSFC/QTOF-MS) for analysis of lignin-derived monomeric compounds in processed lignin samples.

PubMed

Prothmann, Jens; Sun, Mingzhe; Spégel, Peter; Sandahl, Margareta; Turner, Charlotta

2017-12-01

The conversion of lignin to potentially high-value low molecular weight compounds often results in complex mixtures of monomeric and oligomeric compounds. In this study, a method for the quantitative and qualitative analysis of 40 lignin-derived compounds using ultra-high-performance supercritical fluid chromatography coupled to quadrupole-time-of-flight mass spectrometry (UHPSFC/QTOF-MS) has been developed. Seven different columns were explored for maximum selectivity. Makeup solvent composition and ion source settings were optimised using a D-optimal design of experiment (DoE). Differently processed lignin samples were analysed and used for the method validation. The new UHPSFC/QTOF-MS method showed good separation of the 40 compounds within only 6-min retention time, and out of these, 36 showed high ionisation efficiency in negative electrospray ionisation mode. Graphical abstract A rapid and selective method for the quantitative and qualitative analysis of 40 lignin-derived compounds using ultra-high-performance supercritical fluid chromatography coupled to quadrupole-time-of-flight mass spectrometry (UHPSFC/QTOF-MS).

Adsorption detection for polylysine biomolecules based on high-Q silica capillary whispering gallery mode microresonator

NASA Astrophysics Data System (ADS)

Wu, Jixuan; Liu, Bo; Zhang, Hao; Song, Binbin

2017-11-01

A silica-capillary-based whispering gallery mode (WGM) microresonator has been proposed and experimentally demonstrated for the real-time monitoring of the polylysine adsorption process. The spectral characteristics of the WGM resonance dips with high quality factor and good wavelength selectivity have been investigated to evaluate the dynamic process for the binding of polylysine with a capillary surface. The WGM transmission spectrum shows a regular shift with increments of observation time, which could be exploited for the analysis of the polylysine adsorption process. The proposed WGM microresonator system possesses desirable qualities such as high sensitivity, fast response, label-free method, high detection resolution and compactness, which could find promising applications in histology and related bioengineering areas.

The Cognitive Processes Associated with Occupational/Career Indecision: A Model for Gifted Adolescents

ERIC Educational Resources Information Center

Jung, Jae Yup

2013-01-01

This study developed and tested a new model of the cognitive processes associated with occupational/career indecision for gifted adolescents. A survey instrument with rigorous psychometric properties, developed from a number of existing instruments, was administered to a sample of 687 adolescents attending three academically selective high schools…

Pathways to College and STEM Careers: Enhancing the High School Experience

ERIC Educational Resources Information Center

Schneider, Barbara; Broda, Michael; Judy, Justina; Burkander, Kri

2013-01-01

With a rising demand for a college degree and an increasingly complicated college search, application, and selection process, there are a number of interventions designed to ease the college-going process for adolescents and their families. One such intervention, the College Ambition Program (CAP), is specifically designed to be a whole-school…

A Module Experimental Process System Development Unit (MEPSDU)

NASA Technical Reports Server (NTRS)

1982-01-01

Restructuring research objectives from a technical readiness demonstration program to an investigation of high risk, high payoff activities associated with producing photovoltaic modules using non-CZ sheet material is reported. Deletion of the module frame in favor of a frameless design, and modification in cell series parallel electrical interconnect configuration are reviewed. A baseline process sequence was identified for the fabrication of modules using the selected dendritic web sheet material, and economic evaluations of the sequence were completed.

Pyrolysis and hydrolysis of mixed polymer waste comprising polyethylene-terephthalate and polyethylene to sequentially recover [monomers

DOEpatents

Evans, R.J.; Chum, H.L.

1998-10-13

A process is described for using fast pyrolysis in a carrier gas to convert a plastic waste feed stream having a mixed polymeric composition in a manner such that pyrolysis of a given polymer to its high value monomeric constituent occurs prior to pyrolysis of other plastic components therein comprising: selecting a first temperature program range to cause pyrolysis of said given polymer to its high value monomeric constituent prior to a temperature range that causes pyrolysis of other plastic components; selecting a catalyst and support for treating said feed streams with said catalyst to effect acid or base catalyzed reaction pathways to maximize yield or enhance separation of said high value monomeric constituent in said temperature program range; differentially heating said feed stream at a heat rate within the first temperature program range to provide differential pyrolysis for selective recovery of optimum quantities of the high value monomeric constituent prior to pyrolysis of other plastic components; separating the high value monomeric constituents; selecting a second higher temperature range to cause pyrolysis of a different high value monomeric constituent of said plastic waste and differentially heating the feed stream at the higher temperature program range to cause pyrolysis of the different high value monomeric constituent; and separating the different high value monomeric constituent. 83 figs.

Pyrolysis and hydrolysis of mixed polymer waste comprising polyethyleneterephthalate and polyethylene to sequentially recover

DOEpatents

Evans, Robert J.; Chum, Helena L.

1998-01-01

A process of using fast pyrolysis in a carrier gas to convert a plastic waste feedstream having a mixed polymeric composition in a manner such that pyrolysis of a given polymer to its high value monomeric constituent occurs prior to pyrolysis of other plastic components therein comprising: selecting a first temperature program range to cause pyrolysis of said given polymer to its high value monomeric constituent prior to a temperature range that causes pyrolysis of other plastic components; selecting a catalyst and support for treating said feed streams with said catalyst to effect acid or base catalyzed reaction pathways to maximize yield or enhance separation of said high value monomeric constituent in said temperature program range; differentially heating said feed stream at a heat rate within the first temperature program range to provide differential pyrolysis for selective recovery of optimum quantities of the high value monomeric constituent prior to pyrolysis of other plastic components; separating the high value monomeric constituents; selecting a second higher temperature range to cause pyrolysis of a different high value monomeric constituent of said plastic waste and differentially heating the feedstream at the higher temperature program range to cause pyrolysis of the different high value monomeric constituent; and separating the different high value monomeric constituent.

Fatigue Strength Prediction for Titanium Alloy TiAl6V4 Manufactured by Selective Laser Melting

NASA Astrophysics Data System (ADS)

Leuders, Stefan; Vollmer, Malte; Brenne, Florian; Tröster, Thomas; Niendorf, Thomas

2015-09-01

Selective laser melting (SLM), as a metalworking additive manufacturing technique, received considerable attention from industry and academia due to unprecedented design freedom and overall balanced material properties. However, the fatigue behavior of SLM-processed materials often suffers from local imperfections such as micron-sized pores. In order to enable robust designs of SLM components used in an industrial environment, further research regarding process-induced porosity and its impact on the fatigue behavior is required. Hence, this study aims at a transfer of fatigue prediction models, established for conventional process-routes, to the field of SLM materials. By using high-resolution computed tomography, load increase tests, and electron microscopy, it is shown that pore-based fatigue strength predictions for a titanium alloy TiAl6V4 have become feasible. However, the obtained accuracies are subjected to scatter, which is probably caused by the high defect density even present in SLM materials manufactured following optimized processing routes. Based on thorough examination of crack surfaces and crack initiation sites, respectively, implications for optimization of prediction accuracy of the models in focus are deduced.

All Inkjet-Printed Amperometric Multiplexed Biosensors Based on Nanostructured Conductive Hydrogel Electrodes.

PubMed

Li, Lanlan; Pan, Lijia; Ma, Zhong; Yan, Ke; Cheng, Wen; Shi, Yi; Yu, Guihua

2018-06-13

Multiplexing, one of the main trends in biosensors, aims to detect several analytes simultaneously by integrating miniature sensors on a chip. However, precisely depositing electrode materials and selective enzymes on distinct microelectrode arrays remains an obstacle to massively produced multiplexed sensors. Here, we report on a "drop-on-demand" inkjet printing process to fabricate multiplexed biosensors based on nanostructured conductive hydrogels in which the electrode material and several kinds of enzymes were printed on the electrode arrays one by one by employing a multinozzle inkjet system. The whole inkjet printing process can be finished within three rounds of printing and only one round of alignment. For a page of sensor arrays containing 96 working electrodes, the printing process took merely ∼5 min. The multiplexed assays can detect glucose, lactate, and triglycerides in real time with good selectivity and high sensitivity, and the results in phosphate buffer solutions and calibration serum samples are comparable. The inkjet printing process exhibited advantages of high efficiency and accuracy, which opens substantial possibilities for massive fabrication of integrated multiplexed biosensors for human health monitoring.

Lunar-base construction equipment and methods evaluation

NASA Technical Reports Server (NTRS)

Boles, Walter W.; Ashley, David B.; Tucker, Richard L.

1993-01-01

A process for evaluating lunar-base construction equipment and methods concepts is presented. The process is driven by the need for more quantitative, systematic, and logical methods for assessing further research and development requirements in an area where uncertainties are high, dependence upon terrestrial heuristics is questionable, and quantitative methods are seldom applied. Decision theory concepts are used in determining the value of accurate information and the process is structured as a construction-equipment-and-methods selection methodology. Total construction-related, earth-launch mass is the measure of merit chosen for mathematical modeling purposes. The work is based upon the scope of the lunar base as described in the National Aeronautics and Space Administration's Office of Exploration's 'Exploration Studies Technical Report, FY 1989 Status'. Nine sets of conceptually designed construction equipment are selected as alternative concepts. It is concluded that the evaluation process is well suited for assisting in the establishment of research agendas in an approach that is first broad, with a low level of detail, followed by more-detailed investigations into areas that are identified as critical due to high degrees of uncertainty and sensitivity.

Selectivity in Postencoding Connectivity with High-Level Visual Cortex Is Associated with Reward-Motivated Memory

PubMed Central

Murty, Vishnu P.; Tompary, Alexa; Adcock, R. Alison

2017-01-01

Reward motivation has been demonstrated to enhance declarative memory by facilitating systems-level consolidation. Although high-reward information is often intermixed with lower reward information during an experience, memory for high value information is prioritized. How is this selectivity achieved? One possibility is that postencoding consolidation processes bias memory strengthening to those representations associated with higher reward. To test this hypothesis, we investigated the influence of differential reward motivation on the selectivity of postencoding markers of systems-level memory consolidation. Human participants encoded intermixed, trial-unique memoranda that were associated with either high or low-value during fMRI acquisition. Encoding was interleaved with periods of rest, allowing us to investigate experience-dependent changes in connectivity as they related to later memory. Behaviorally, we found that reward motivation enhanced 24 h associative memory. Analysis of patterns of postencoding connectivity showed that, even though learning trials were intermixed, there was significantly greater connectivity with regions of high-level, category-selective visual cortex associated with high-reward trials. Specifically, increased connectivity of category-selective visual cortex with both the VTA and the anterior hippocampus predicted associative memory for high- but not low-reward memories. Critically, these results were independent of encoding-related connectivity and univariate activity measures. Thus, these findings support a model by which the selective stabilization of memories for salient events is supported by postencoding interactions with sensory cortex associated with reward. SIGNIFICANCE STATEMENT Reward motivation is thought to promote memory by supporting memory consolidation. Yet, little is known as to how brain selects relevant information for subsequent consolidation based on reward. We show that experience-dependent changes in connectivity of both the anterior hippocampus and the VTA with high-level visual cortex selectively predicts memory for high-reward memoranda at a 24 h delay. These findings provide evidence for a novel mechanism guiding the consolidation of memories for valuable events, namely, postencoding interactions between neural systems supporting mesolimbic dopamine activation, episodic memory, and perception. PMID:28100737

Sex-ratio control erodes sexual selection, revealing evolutionary feedback from adaptive plasticity.

PubMed

Fawcett, Tim W; Kuijper, Bram; Weissing, Franz J; Pen, Ido

2011-09-20

Female choice is a powerful selective force, driving the elaboration of conspicuous male ornaments. This process of sexual selection has profound implications for many life-history decisions, including sex allocation. For example, females with attractive partners should produce more sons, because these sons will inherit their father's attractiveness and enjoy high mating success, thereby yielding greater fitness returns than daughters. However, previous research has overlooked the fact that there is a reciprocal feedback from life-history strategies to sexual selection. Here, using a simple mathematical model, we show that if mothers adaptively control offspring sex in relation to their partner's attractiveness, sexual selection is weakened and male ornamentation declines. This weakening occurs because the ability to determine offspring sex reduces the fitness difference between females with attractive and unattractive partners. We use individual-based, evolutionary simulations to show that this result holds under more biologically realistic conditions. Sexual selection and sex allocation thus interact in a dynamic fashion: The evolution of conspicuous male ornaments favors sex-ratio adjustment, but this conditional strategy then undermines the very same process that generated it, eroding sexual selection. We predict that, all else being equal, the most elaborate sexual displays should be seen in species with little or no control over offspring sex. The feedback process we have described points to a more general evolutionary principle, in which a conditional strategy weakens directional selection on another trait by reducing fitness differences.

Microbiological stimulation of phytoremediation process using Salvinia natans to mercury contamined water

NASA Astrophysics Data System (ADS)

Filyarovskaya, Viktoriya; Sitarska, Magdalena; Traczewska, Teodora; Wolf, Mirela

2017-11-01

An alternative to traditional cleaning methods of heavy metals in the water environment is phytoremediation. They efficiency depends on used technological process conditions as well as plant species. One of the most dangerous metallic elements mercury plays a particular role, which is a trace element and a physiologically foreign in living organisms. Mercury has a high degree of toxicity with strong affinity to thiol groups. This may cause an adverse effect on the enzymatic processes and consequently inhibiting the physiological functions. Because of high risk for human health, water environment treatment from mercury is essential proecological action. Mercury removal studies were conducted using Salvinia natans pleustofit, sampled from its natural water environment. In the first step, epiphytic bacteria, which was resistant to high concentrations of mercury (0,6 mgHg/l), was isolated from the plant and than selected by the tiles gradient mthod. In the next step, the identification using molecular biology methods was made. In the following step plant Salvinia natans was exposure to high levels of mercury in the presence of the three isolated Pseudomonas strains with exceptional resistance characteristics to environmental factors. Has been found a positive bacteria effect on the plant condition because the selected strains belong to Pseudomonas species producing materials supporting plant growth. The use of microbial stimulation to phytoremediation by hyperaccumulator Salvinia natans can multiply the effectiveness of the process.

Poly(ethylene imine)-based granular sorbents by a new process of templated gel-filling. High capacity and selectivity of copper sorption in acidic and alkaline media

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chanda, M.; Rempel, G.L.

A new process has been developed for making granular gel-type sorbents from chelating resins using metal ion as template. Named as templated gel-filling, the process uses the chosen metal as templating host ion on high-surface-area silica to build a templated gel layer from a solution of the chelating resin in a suitable solvent in which the resin is soluble but its metal complex is insoluble. After cross-linking the templated gel layer, the silica support is removed by alkali to produce a hollow shell of the templated gel. The shells are then soaked in a concentrated aqueous solution of the samemore » metal ion and suspended in the same resin solution to afford gel-filling. The shells thus filled with metal-templated gel are treated with cross-linking agent, followed by acid to remove the template ion and activate the resin for metal sorption. Poly(ethyleneimine) and its partially ethylated derivative have been used to produce granular gel-type sorbents by this process, with Cu(II) as the template ion. These sorbents are found to offer high capacity and selectivity for copper over nickel, cobalt, and zinc in both acidic and alkaline media. Containing a relatively high fraction of imbibed water, the sorbents exhibit markedly enhanced rate behavior, in both sorption and stripping.« less

The OSIRIS-REx Mission Sample Site Selection Process

NASA Astrophysics Data System (ADS)

Beshore, Edward C.; Lauretta, Dante

2014-11-01

In September of 2016, the OSIRIS-REx (Origins, Spectral Interpretation, Resource Identification, Security, REgolith eXplorer) spacecraft will depart for asteroid (101955) Bennu, and in doing so, will turn an important corner in the exploration of the solar system. After arriving at Bennu in the fall of 2018, OSIRIS-REx will undertake a program of observations designed to select a site suitable for retrieving a sample that will be returned to the Earth in 2023. The third mission in NASA’s New Frontiers program, OSIRIS-REx will return over 60 grams from Bennu’s surface.OSIRIS-REx is unique because the science team will have an operational role to play in preparing data products needed to select a sample site. These include products used to ensure flight system safety — topographic maps and shape models, temperature measurements, maps of hazards — as well as assessments of sampleability and science value. The timing and production of these will be presented, as will the high-level decision-making tools and processes for the interim and final site selection processes.

A dissociation between selective attention and conscious awareness in the representation of temporal order information.

PubMed

Eimer, Martin; Grubert, Anna

2015-09-01

Previous electrophysiological studies have shown that attentional selection processes are highly sensitive to the temporal order of task-relevant visual events. When two successively presented colour-defined target stimuli are separated by a stimulus onset asynchrony (SOA) of only 10 ms, the onset latencies of N2pc components to these stimuli (which reflect their attentional selection) precisely match their objective temporal separation. We tested whether such small onset differences are accessible to conscious awareness by instructing participants to report the category (letter or digit) of the first of two target-colour items that were separated by an SOA of 10, 20, or 30 ms. Performance was at chance level for the 10 ms SOA, demonstrating that temporal order information which is available to attentional control processes cannot be utilized for conscious temporal order judgments. These results provide new evidence that selective attention and conscious awareness are functionally separable, and support the hypothesis that attention and awareness operate at different stages of cognitive processing. Copyright © 2015 Elsevier Inc. All rights reserved.

Gold nanoparticles supported on titanium dioxide: an efficient catalyst for highly selective synthesis of benzoxazoles and benzimidazoles.

PubMed

Tang, Lin; Guo, Xuefeng; Yang, Yu; Zha, Zhenggen; Wang, Zhiyong

2014-06-11

A highly efficient and selective reaction for the synthesis of 2-substituted benzoxazoles and benzimidazoles catalyzed by Au/TiO2 has been developed via two hydrogen-transfer processes. This reaction has a good tolerance to air and water, a wide substrate scope, and represents a new avenue for practical C-N and C-O bond formation. More importantly, no additional additives, oxidants and reductants are required for the reaction and the catalyst can be recovered and reused readily.

Phenylated polyimides prepared from 3,6-diarylpyromellitic dianhydride and aromatic diamines

NASA Technical Reports Server (NTRS)

Harris, Frank W. (Inventor)

1992-01-01

A new class of soluble phenylated polyimides made from 3,6-diarypyromellitic dianhydride and process for the manufacture of the 3,6-diarypyromellitic dianhydride starting material. The polyimides obtained with said dianhydride are readily soluble in appropriate organic solvents and are distinguished by excellent thermal, electrical and/or mechanical properties making the polyimides ideally suited as coating materials for microelectronic apparatii, as membranes for selective molecular separation or permeation or selective gas separation or permeation, or as reinforcing fibers in molecular composites, or as high modulus, high tensile strength fibers.

A universal deep learning approach for modeling the flow of patients under different severities.

PubMed

Jiang, Shancheng; Chin, Kwai-Sang; Tsui, Kwok L

2018-02-01

The Accident and Emergency Department (A&ED) is the frontline for providing emergency care in hospitals. Unfortunately, relative A&ED resources have failed to keep up with continuously increasing demand in recent years, which leads to overcrowding in A&ED. Knowing the fluctuation of patient arrival volume in advance is a significant premise to relieve this pressure. Based on this motivation, the objective of this study is to explore an integrated framework with high accuracy for predicting A&ED patient flow under different triage levels, by combining a novel feature selection process with deep neural networks. Administrative data is collected from an actual A&ED and categorized into five groups based on different triage levels. A genetic algorithm (GA)-based feature selection algorithm is improved and implemented as a pre-processing step for this time-series prediction problem, in order to explore key features affecting patient flow. In our improved GA, a fitness-based crossover is proposed to maintain the joint information of multiple features during iterative process, instead of traditional point-based crossover. Deep neural networks (DNN) is employed as the prediction model to utilize their universal adaptability and high flexibility. In the model-training process, the learning algorithm is well-configured based on a parallel stochastic gradient descent algorithm. Two effective regularization strategies are integrated in one DNN framework to avoid overfitting. All introduced hyper-parameters are optimized efficiently by grid-search in one pass. As for feature selection, our improved GA-based feature selection algorithm has outperformed a typical GA and four state-of-the-art feature selection algorithms (mRMR, SAFS, VIFR, and CFR). As for the prediction accuracy of proposed integrated framework, compared with other frequently used statistical models (GLM, seasonal-ARIMA, ARIMAX, and ANN) and modern machine models (SVM-RBF, SVM-linear, RF, and R-LASSO), the proposed integrated "DNN-I-GA" framework achieves higher prediction accuracy on both MAPE and RMSE metrics in pairwise comparisons. The contribution of our study is two-fold. Theoretically, the traditional GA-based feature selection process is improved to have less hyper-parameters and higher efficiency, and the joint information of multiple features is maintained by fitness-based crossover operator. The universal property of DNN is further enhanced by merging different regularization strategies. Practically, features selected by our improved GA can be used to acquire an underlying relationship between patient flows and input features. Predictive values are significant indicators of patients' demand and can be used by A&ED managers to make resource planning and allocation. High accuracy achieved by the present framework in different cases enhances the reliability of downstream decision makings. Copyright © 2017 Elsevier B.V. All rights reserved.

Molecular imprinting ratiometric fluorescence sensor for highly selective and sensitive detection of phycocyanin.

PubMed

Wang, Xiaoyan; Yu, Jialuo; Kang, Qi; Shen, Dazhong; Li, Jinhua; Chen, Lingxin

2016-03-15

A facile strategy was developed to prepare molecular imprinting ratiometric fluorescence sensor for highly selective and sensitive detection of phycocyanin (PC) based on fluorescence resonance energy transfer (FRET), via a sol-gel polymerization process using nitrobenzoxadiazole (NBD) as fluorescent signal source. The ratio of two fluorescence peak emission intensities of NBD and PC was utilized to determine the concentration of PC, which could effectively reduce the background interference and fluctuation of diverse conditions. As a result, this sensor obtained high sensitivity with a low detection limit of 0.14 nM within 6 min, and excellent recognition specificity for PC over its analogues with a high imprinting factor of 9.1. Furthermore, the sensor attained high recoveries in the range of 93.8-110.2% at three spiking levels of PC, with precisions below 4.7% in seawater and lake water samples. The developed sensor strategy demonstrated simplicity, reliability, rapidity, high selectivity and high sensitivity, proving to be a feasible way to develop high efficient fluorescence sensors and thus potentially applicable for ultratrace analysis of complicated matrices. Copyright © 2015 Elsevier B.V. All rights reserved.

System integration and demonstration of adhesive bonded high temperature aluminum alloys for aerospace structure, phase 2

NASA Technical Reports Server (NTRS)

Falcone, Anthony; Laakso, John H.

1993-01-01

Adhesive bonding materials and processes were evaluated for assembly of future high-temperature aluminum alloy structural components such as may be used in high-speed civil transport aircraft and space launch vehicles. A number of candidate high-temperature adhesives were selected and screening tests were conducted using single lap shear specimens. The selected adhesives were then used to bond sandwich (titanium core) test specimens, adhesive toughness test specimens, and isothermally aged lap shear specimens. Moderate-to-high lap shear strengths were obtained from bonded high-temperature aluminum and silicon carbide particulate-reinforced (SiC(sub p)) aluminum specimens. Shear strengths typically exceeded 3500 to 4000 lb/in(sup 2) and flatwise tensile strengths exceeded 750 lb/in(sup 2) even at elevated temperatures (300 F) using a bismaleimide adhesive. All faceskin-to-core bonds displayed excellent tear strength. The existing production phosphoric acid anodize surface preparation process developed at Boeing was used, and gave good performance with all of the aluminum and silicon carbide particulate-reinforced aluminum alloys investigated. The results of this program support using bonded assemblies of high-temperature aluminum components in applications where bonding is often used (e.g., secondary structures and tear stoppers).

Optical-Correlator Neural Network Based On Neocognitron

NASA Technical Reports Server (NTRS)

Chao, Tien-Hsin; Stoner, William W.

1994-01-01

Multichannel optical correlator implements shift-invariant, high-discrimination pattern-recognizing neural network based on paradigm of neocognitron. Selected as basic building block of this neural network because invariance under shifts is inherent advantage of Fourier optics included in optical correlators in general. Neocognitron is conceptual electronic neural-network model for recognition of visual patterns. Multilayer processing achieved by iteratively feeding back output of feature correlator to input spatial light modulator and updating Fourier filters. Neural network trained by use of characteristic features extracted from target images. Multichannel implementation enables parallel processing of large number of selected features.

Direct and Selective Synthesis of Hydrogen Peroxide over Palladium-Tellurium Catalysts at Ambient Pressure.

PubMed

Tian, Pengfei; Xu, Xingyan; Ao, Can; Ding, Doudou; Li, Wei; Si, Rui; Tu, Weifeng; Xu, Jing; Han, Yi-Fan

2017-09-11

Highly selective hydrogen peroxide (H 2 O 2 ) synthesis directly from H 2 and O 2 is a strongly desired reaction for green processes. Herein a highly efficient palladium-tellurium (Pd-Te/TiO 2 ) catalyst with a selectivity of nearly 100 % toward H 2 O 2 under mild conditions (283 K, 0.1 MPa, and a semi-batch continuous flow reactor) is reported. The size of Pd particles was remarkably reduced from 2.1 nm to 1.4 nm with the addition of Te. The Te-modified Pd surface could significantly weaken the dissociative activation of O 2 , leading to the non-dissociative hydrogenation of O 2 . Density functional theory calculations illuminated the critical role of Te in the selective hydrogenation of O 2 , in that the active sites composed of Pd and Te could significantly restrain side reactions. This work has made significant progress on the development of high-selectivity catalysts for the direct synthesis of H 2 O 2 at ambient pressure. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Diode-laser-based RIMS measurements of strontium-90

NASA Astrophysics Data System (ADS)

Bushaw, B. A.; Cannon, B. D.

1998-12-01

Double- and triple-resonance excitation schemes for the ionization of strontium are presented. Use of single-mode diode lasers for the resonance excitations provides a high degree of optical isotopic selectivity: with double-resonance, selectivity of >104 for 90Sr against the stable Sr isotopes has been demonstrated. Measurement of lineshapes and stable isotope shifts in the triple-resonance process indicate that optical selectivity should increase to ˜109. When combined with mass spectrometer selectivity this is sufficient for measurement of 90Sr at background environmental levels. Additionally, autoionizing resonances have been investigated for improving ionization efficiency with lower power lasers.

Beyond time and space: The effect of a lateralized sustained attention task and brain stimulation on spatial and selective attention.

PubMed

Shalev, Nir; De Wandel, Linde; Dockree, Paul; Demeyere, Nele; Chechlacz, Magdalena

2017-10-03

The Theory of Visual Attention (TVA) provides a mathematical formalisation of the "biased competition" account of visual attention. Applying this model to individual performance in a free recall task allows the estimation of 5 independent attentional parameters: visual short-term memory (VSTM) capacity, speed of information processing, perceptual threshold of visual detection; attentional weights representing spatial distribution of attention (spatial bias), and the top-down selectivity index. While the TVA focuses on selection in space, complementary accounts of attention describe how attention is maintained over time, and how temporal processes interact with selection. A growing body of evidence indicates that different facets of attention interact and share common neural substrates. The aim of the current study was to modulate a spatial attentional bias via transfer effects, based on a mechanistic understanding of the interplay between spatial, selective and temporal aspects of attention. Specifically, we examined here: (i) whether a single administration of a lateralized sustained attention task could prime spatial orienting and lead to transferable changes in attentional weights (assigned to the left vs right hemi-field) and/or other attentional parameters assessed within the framework of TVA (Experiment 1); (ii) whether the effects of such spatial-priming on TVA parameters could be further enhanced by bi-parietal high frequency transcranial random noise stimulation (tRNS) (Experiment 2). Our results demonstrate that spatial attentional bias, as assessed within the TVA framework, was primed by sustaining attention towards the right hemi-field, but this spatial-priming effect did not occur when sustaining attention towards the left. Furthermore, we show that bi-parietal high-frequency tRNS combined with the rightward spatial-priming resulted in an increased attentional selectivity. To conclude, we present a novel, theory-driven method for attentional modulation providing important insights into how the spatial and temporal processes in attention interact with attentional selection. Copyright © 2017 Elsevier Ltd. All rights reserved.

Tunable catalytic properties of bi-functional mixed oxides in ethanol conversion to high value compounds

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ramasamy, Karthikeyan K.; Gray, Michel J.; Job, Heather M.

2016-04-10

tA highly versatile ethanol conversion process to selectively generate high value compounds is pre-sented here. By changing the reaction temperature, ethanol can be selectively converted to >C2alcohols/oxygenates or phenolic compounds over hydrotalcite derived bi-functional MgO–Al2O3cata-lyst via complex cascade mechanism. Reaction temperature plays a role in whether aldol condensationor the acetone formation is the path taken in changing the product composition. This article containsthe catalytic activity comparison between the mono-functional and physical mixture counterpart to thehydrotalcite derived mixed oxides and the detailed discussion on the reaction mechanisms.

Applications of absorption spectroscopy using quantum cascade lasers.

PubMed

Zhang, Lizhu; Tian, Guang; Li, Jingsong; Yu, Benli

2014-01-01

Infrared laser absorption spectroscopy (LAS) is a promising modern technique for sensing trace gases with high sensitivity, selectivity, and high time resolution. Mid-infrared quantum cascade lasers, operating in a pulsed or continuous wave mode, have potential as spectroscopic sources because of their narrow linewidths, single mode operation, tunability, high output power, reliability, low power consumption, and compactness. This paper reviews some important developments in modern laser absorption spectroscopy based on the use of quantum cascade laser (QCL) sources. Among the various laser spectroscopic methods, this review is focused on selected absorption spectroscopy applications of QCLs, with particular emphasis on molecular spectroscopy, industrial process control, combustion diagnostics, and medical breath analysis.

Tunable catalytic properties of bi-functional mixed oxides in ethanol conversion to high value compounds

DOE PAGES

Ramasamy, Karthikeyan K.; Gray, Michel; Job, Heather; ...

2016-02-03

Here, a highly versatile ethanol conversion process to selectively generate high value compounds is presented here. By changing the reaction temperature, ethanol can be selectively converted to >C 2 alcohols/oxygenates or phenolic compounds over hydrotalcite derived bi-functional MgO–Al 2O 3 catalyst via complex cascade mechanism. Reaction temperature plays a role in whether aldol condensation or the acetone formation is the path taken in changing the product composition. This article contains the catalytic activity comparison between the mono-functional and physical mixture counterpart to the hydrotalcite derived mixed oxides and the detailed discussion on the reaction mechanisms.

Effect of nitrogen application on the physicochemical properties of selected rice varieties

USDA-ARS?s Scientific Manuscript database

Rice with high amylose concentration (AM), low breakdown and high setback, as measured by the Rapid Visco Analyzer (RVA), is best suited for use by the parboiling and canning industries as these properties correlates with reduced starch solids loss and improved grain integrity after processing. This...

Brazilian and Mexican experiences in the study of incipient domestication.

PubMed

Lins Neto, Ernani Machado de Freitas; Peroni, Nivaldo; Casas, Alejandro; Parra, Fabiola; Aguirre, Xitlali; Guillén, Susana; Albuquerque, Ulysses Paulino

2014-04-02

Studies of domestication enables a better understanding of human cultures, landscape changes according to peoples' purposes, and evolutionary consequences of human actions on biodiversity. This review aimed at discussing concepts, hypotheses, and current trends in studies of domestication of plants, using examples of cases studied in regions of Mesoamerica and Brazil. We analyzed trends of ethnobiological studies contributing to document processes of domestication and to establish criteria for biodiversity conservation based on traditional ecological knowledge. Based on reviewing our own and other authors' studies we analyzed management patterns and evolutionary trends associated to domestication occurring at plant populations and landscape levels. Particularly, we systematized information documenting: ethnobotanical aspects about plant management and artificial selection mechanisms, morphological consequences of plant management, population genetics of wild and managed plant populations, trends of change in reproduction systems of plants associated to management, and other ecological and physiological aspects influenced by management and domestication. Based on the analysis of study cases of 20 native species of herbs, shrubs and trees we identified similar criteria of artificial selection in different cultural contexts of Mexico and Brazil. Similar evolutionary trends were also identified in morphology (selection in favor of gigantism of useful and correlated parts); organoleptic characteristics such as taste, toxicity, color, texture; reproductive biology, mainly breeding system, phenological changes, and population genetics aspects, maintenance or increasing of genetic diversity in managed populations, high gene flow with wild relatives and low structure maintained by artificial selection. Our review is a first attempt to unify research methods for analyzing a high diversity of processes. Further research should emphasize deeper analyses of contrasting and diverse cultural and ecological contexts for a better understanding of evolution under incipient processes of domestication. Higher research effort is particularly required in Brazil, where studies on this topic are scarcer than in Mexico but where diversity of human cultures managing their also high plant resources diversity offer high potential for documenting the diversity of mechanisms of artificial selection and evolutionary trends. Comparisons and evaluations of incipient domestication in the regions studied as well as the Andean area would significantly contribute to understanding origins and diffusion of the experience of managing and domesticating plants.

Analysis of Information Content in High-Spectral Resolution Sounders using Subset Selection Analysis

NASA Technical Reports Server (NTRS)

Velez-Reyes, Miguel; Joiner, Joanna

1998-01-01

In this paper, we summarize the results of the sensitivity analysis and data reduction carried out to determine the information content of AIRS and IASI channels. The analysis and data reduction was based on the use of subset selection techniques developed in the linear algebra and statistical community to study linear dependencies in high dimensional data sets. We applied the subset selection method to study dependency among channels by studying the dependency among their weighting functions. Also, we applied the technique to study the information provided by the different levels in which the atmosphere is discretized for retrievals and analysis. Results from the method correlate well with intuition in many respects and point out to possible modifications for band selection in sensor design and number and location of levels in the analysis process.

Label-Free SERS Selective Detection of Dopamine and Serotonin Using Graphene-Au Nanopyramid Heterostructure.

PubMed

Wang, Pu; Xia, Ming; Liang, Owen; Sun, Ke; Cipriano, Aaron F; Schroeder, Thomas; Liu, Huinan; Xie, Ya-Hong

2015-10-20

Ultrasensitive detection and spatially resolved mapping of neurotransmitters, dopamine and serotonin, are critical to facilitate understanding brain functions and investigate the information processing in neural networks. In this work, we demonstrated single molecule detection of dopamine and serotonin using a graphene-Au nanopyramid heterostructure platform. The quasi-periodic Au structure boosts high-density and high-homogeneity hotspots resulting in ultrahigh sensitivity with a surface enhanced Raman spectroscopic (SERS) enhancement factor ∼10(10). A single layer graphene superimposed on a Au structure not only can locate SERS hot spots but also modify the surface chemistry to realize selective enhancement Raman yield. Dopamine and serotonin could be detected and distinguished from each other at 10(-10) M level in 1 s data acquisition time without any pretreatment and labeling process. Moreover, the heterostructure realized nanomolar detection of neurotransmitters in the presence of simulated body fluids. These findings represent a step forward in enabling in-depth studies of neurological processes including those closely related to brain activity mapping (BAM).

Steam-blanched highbush blueberry (Vaccinium corymbosum L.) juice: phenolic profile and antioxidant capacity in relation to cultivar selection.

PubMed

Brambilla, Ada; Lo Scalzo, Roberto; Bertolo, Gianni; Torreggiani, Danila

2008-04-23

High-quality standards in blueberry juice can be obtained only taking into account fruit compositional variability and its preservation along the processing chain. In this work, five highbush blueberry cultivars from the same environmental growing conditions were individually processed into juice after an initial blanching step and the influence was studied of the cultivar on juice phenolic content, distribution and relative antioxidant activity, measured as scavenging capacity on the artificial free-radical 2,2-diphenyl-1-picrylhydrazyl (DPPH*). A chromatographic protocol was developed to separate all main phenolic compounds in berries. A total of 15 glycosylated anthocyanins, catechin, galactoside, glucoside, and rhamnoside quercetin 3-derivatives, and main benzoic and cinnamic acids were identified. The total content and relative distribution in anthocyanins, chlorogenic acid, and quercetin of each juice were dependent upon cultivar, and the total content was highly correlated (rxy=0.97) to the antioxidant capacity. A selective protective effect of berry blanching in juice processing can be observed on more labile anthocyanin compounds.

Optimization and Simulation of SLM Process for High Density H13 Tool Steel Parts

NASA Astrophysics Data System (ADS)

Laakso, Petri; Riipinen, Tuomas; Laukkanen, Anssi; Andersson, Tom; Jokinen, Antero; Revuelta, Alejandro; Ruusuvuori, Kimmo

This paper demonstrates the successful printing and optimization of processing parameters of high-strength H13 tool steel by Selective Laser Melting (SLM). D-Optimal Design of Experiments (DOE) approach is used for parameter optimization of laser power, scanning speed and hatch width. With 50 test samples (1×1×1cm) we establish parameter windows for these three parameters in relation to part density. The calculated numerical model is found to be in good agreement with the density data obtained from the samples using image analysis. A thermomechanical finite element simulation model is constructed of the SLM process and validated by comparing the calculated densities retrieved from the model with the experimentally determined densities. With the simulation tool one can explore the effect of different parameters on density before making any printed samples. Establishing a parameter window provides the user with freedom for parameter selection such as choosing parameters that result in fastest print speed.

Ni Nanoparticles Supported on Cage-Type Mesoporous Silica for CO2 Hydrogenation with High CH4 Selectivity.

PubMed

Budi, Canggih Setya; Wu, Hung-Chi; Chen, Ching-Shiun; Saikia, Diganta; Kao, Hsien-Ming

2016-09-08

Ni nanoparticles (around 4 nm diameter) were successfully supported on cage-type mesoporous silica SBA-16 (denoted as Ni@SBA-16) via wet impregnation at pH 9, followed by the calcination-reduction process. The Ni@SBA-16 catalyst with a very high Ni loading amount (22.9 wt %) exhibited exceptionally high CH4 selectivity for CO2 hydrogenation. At a nearly identical loading amount, the Ni@SBA-16 catalysts with smaller particle size of Ni NPs surprisingly exhibited a higher catalytic activity of CO2 hydrogenation and also led to a higher selectivity on CH4 formation than the Ni@SiO2 catalysts. This enhanced activity of the Ni@SBA-16 catalyst is suggested to be an accumulative result of the advantageous structural properties of the support SBA-16 and the well confined Ni NPs within the support; both induced a favorable reaction pathway for high selectivity of CH4 in CO2 hydrogenation. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Ultrathin and Ion-Selective Janus Membranes for High-Performance Osmotic Energy Conversion.

PubMed

Zhang, Zhen; Sui, Xin; Li, Pei; Xie, Ganhua; Kong, Xiang-Yu; Xiao, Kai; Gao, Longcheng; Wen, Liping; Jiang, Lei

2017-07-05

The osmotic energy existing in fluids is recognized as a promising "blue" energy source that can help solve the global issues of energy shortage and environmental pollution. Recently, nanofluidic channels have shown great potential for capturing this worldwide energy because of their novel transport properties contributed by nanoconfinement. However, with respect to membrane-scale porous systems, high resistance and undesirable ion selectivity remain bottlenecks, impeding their applications. The development of thinner, low-resistance membranes, meanwhile promoting their ion selectivity, is a necessity. Here, we engineered ultrathin and ion-selective Janus membranes prepared via the phase separation of two block copolymers, which enable osmotic energy conversion with power densities of approximately 2.04 W/m 2 by mixing natural seawater and river water. Both experiments and continuum simulation help us to understand the mechanism for how membrane thickness and channel structure dominate the ion transport process and overall device performance, which can serve as a general guiding principle for the future design of nanochannel membranes for high-energy concentration cells.

Cultural group selection plays an essential role in explaining human cooperation: A sketch of the evidence.

PubMed

Richerson, Peter; Baldini, Ryan; Bell, Adrian V; Demps, Kathryn; Frost, Karl; Hillis, Vicken; Mathew, Sarah; Newton, Emily K; Naar, Nicole; Newson, Lesley; Ross, Cody; Smaldino, Paul E; Waring, Timothy M; Zefferman, Matthew

2016-01-01

Human cooperation is highly unusual. We live in large groups composed mostly of non-relatives. Evolutionists have proposed a number of explanations for this pattern, including cultural group selection and extensions of more general processes such as reciprocity, kin selection, and multi-level selection acting on genes. Evolutionary processes are consilient; they affect several different empirical domains, such as patterns of behavior and the proximal drivers of that behavior. In this target article, we sketch the evidence from five domains that bear on the explanatory adequacy of cultural group selection and competing hypotheses to explain human cooperation. Does cultural transmission constitute an inheritance system that can evolve in a Darwinian fashion? Are the norms that underpin institutions among the cultural traits so transmitted? Do we observe sufficient variation at the level of groups of considerable size for group selection to be a plausible process? Do human groups compete, and do success and failure in competition depend upon cultural variation? Do we observe adaptations for cooperation in humans that most plausibly arose by cultural group selection? If the answer to one of these questions is "no," then we must look to other hypotheses. We present evidence, including quantitative evidence, that the answer to all of the questions is "yes" and argue that we must take the cultural group selection hypothesis seriously. If culturally transmitted systems of rules (institutions) that limit individual deviance organize cooperation in human societies, then it is not clear that any extant alternative to cultural group selection can be a complete explanation.

Complex electronic waste treatment - An effective process to selectively recover copper with solutions containing different ammonium salts.

PubMed

Sun, Z H I; Xiao, Y; Sietsma, J; Agterhuis, H; Yang, Y

2016-11-01

Recovery of valuable metals from electronic waste has been highlighted by the EU directives. The difficulties for recycling are induced by the high complexity of such waste. In this research, copper could be selectively recovered using an ammonia-based process, from industrially processed information and communication technology (ICT) waste with high complexity. A detailed understanding on the role of ammonium salt was focused during both stages of leaching copper into a solution and the subsequent step for copper recovery from the solution. By comparing the reactivity of the leaching solution with different ammonium salts, their physiochemical behaviour as well as the leaching efficiency could be identified. The copper recovery rate could reach 95% with ammonium carbonate as the leaching salt. In the stage of copper recovery from the solution, electrodeposition was introduced without an additional solvent extraction step and the electrochemical behaviour of the solution was figured out. With a careful control of the electrodeposition conditions, the current efficiency could be improved to be 80-90% depending on the ammonia salts and high purity copper (99.9wt.%). This research provides basis for improving the recyclability and efficiency of copper recovery from such electronic waste and the whole process design for copper recycling. Copyright © 2016 Elsevier Ltd. All rights reserved.

Thermal analysis on Al7075/Al2O3 metal matrix composites fabricated by stir casting process

NASA Astrophysics Data System (ADS)

Jacob, S.; Shajin, S.; Gnanavel, C.

2017-03-01

Metal matrix Composites (MMC’s) have evoked a keen interest in recent times for various applications in aerospace, renewable energy and automotive industries due to their superior strength, low cost, easy availability and high temperature resistance [1]. The crack and propagation occurs in conventional materials without any appreciable indication in a short span. Hence composite materials are preferred nowadays to overcome this problem [2]. The process of metal matrix composites (MMC’s) is to unite the enviable attributes of metals and ceramics. The Stir casting method is used for producing aluminium metal matrix composites (AMC’s). A key challenge of the process is to spread the ceramic particles to achieve a defect free microstructure [2]. By carefully selecting stir casting processing specification, such as stirring time, temperature of the melt and blade angle, the desired microstructure can be obtained. The focus of this work is to develop a high strength particulate strengthen aluminium metal matrix composites, and Al7075 was selected which can offer high strength without much disturbing ductility of metal matrix [4]. The composites will be examined using standard metallurgical and mechanical tests. The cast composites are analysed to Laser flash analysis (LFA) to determine Thermal conductivity [5]. Also changes in microstructure are determined by using SEM analysis.

Investigating the CO 2 laser cutting parameters of MDF wood composite material

NASA Astrophysics Data System (ADS)

Eltawahni, H. A.; Olabi, A. G.; Benyounis, K. Y.

2011-04-01

Laser cutting of medium density fibreboard (MDF) is a complicated process and the selection of the process parameters combinations is essential to get the highest quality cut section. This paper presents a means for selecting the process parameters for laser cutting of MDF based on the design of experiments (DOE) approach. A CO 2 laser was used to cut three thicknesses, 4, 6 and 9 mm, of MDF panels. The process factors investigated are: laser power, cutting speed, air pressure and focal point position. In this work, cutting quality was evaluated by measuring the upper kerf width, the lower kerf width, the ratio between the upper kerf width to the lower kerf width, the cut section roughness and the operating cost. The effect of each factor on the quality measures was determined. The optimal cutting combinations were presented in favours of high quality process output and in favours of low cutting cost.

Analysis of the critical thinking process of junior high school students in solving geometric problems by utilizing the v-a-k learning styles model

NASA Astrophysics Data System (ADS)

Hananto, R. B.; Kusmayadi, T. A.; Riyadi

2018-05-01

The research aims to identify the critical thinking process of students in solving geometry problems. The geometry problem selected in this study was the building of flat side room (cube). The critical thinking process was implemented to visual, auditory and kinesthetic learning styles. This research was a descriptive analysis research using qualitative method. The subjects of this research were 3 students selected by purposive sampling consisting of visual, auditory, and kinesthetic learning styles. Data collection was done through test, interview, and observation. The results showed that the students' critical thinking process in identifying and defining steps for each learning style were similar in solving problems. The critical thinking differences were seen in enumerate, analyze, list, and self-correct steps. It was also found that critical thinking process of students with kinesthetic learning style was better than visual and auditory learning styles.

A hybrid approach identifies metabolic signatures of high-producers for chinese hamster ovary clone selection and process optimization.

PubMed

Popp, Oliver; Müller, Dirk; Didzus, Katharina; Paul, Wolfgang; Lipsmeier, Florian; Kirchner, Florian; Niklas, Jens; Mauch, Klaus; Beaucamp, Nicola

2016-09-01

In-depth characterization of high-producer cell lines and bioprocesses is vital to ensure robust and consistent production of recombinant therapeutic proteins in high quantity and quality for clinical applications. This requires applying appropriate methods during bioprocess development to enable meaningful characterization of CHO clones and processes. Here, we present a novel hybrid approach for supporting comprehensive characterization of metabolic clone performance. The approach combines metabolite profiling with multivariate data analysis and fluxomics to enable a data-driven mechanistic analysis of key metabolic traits associated with desired cell phenotypes. We applied the methodology to quantify and compare metabolic performance in a set of 10 recombinant CHO-K1 producer clones and a host cell line. The comprehensive characterization enabled us to derive an extended set of clone performance criteria that not only captured growth and product formation, but also incorporated information on intracellular clone physiology and on metabolic changes during the process. These criteria served to establish a quantitative clone ranking and allowed us to identify metabolic differences between high-producing CHO-K1 clones yielding comparably high product titers. Through multivariate data analysis of the combined metabolite and flux data we uncovered common metabolic traits characteristic of high-producer clones in the screening setup. This included high intracellular rates of glutamine synthesis, low cysteine uptake, reduced excretion of aspartate and glutamate, and low intracellular degradation rates of branched-chain amino acids and of histidine. Finally, the above approach was integrated into a workflow that enables standardized high-content selection of CHO producer clones in a high-throughput fashion. In conclusion, the combination of quantitative metabolite profiling, multivariate data analysis, and mechanistic network model simulations can identify metabolic traits characteristic of high-performance clones and enables informed decisions on which clones provide a good match for a particular process platform. The proposed approach also provides a mechanistic link between observed clone phenotype, process setup, and feeding regimes, and thereby offers concrete starting points for subsequent process optimization. Biotechnol. Bioeng. 2016;113: 2005-2019. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Effect of Electron Beam Freeform Fabrication (EBF3) Processing Parameters on Composition of Ti-6-4

NASA Technical Reports Server (NTRS)

Lach, Cynthia L.; Taminger, Karen; Schuszler, A. Bud, II; Sankaran, Sankara; Ehlers, Helen; Nasserrafi, Rahbar; Woods, Bryan

2007-01-01

The Electron Beam Freeform Fabrication (EBF3) process developed at NASA Langley Research Center was evaluated using a design of experiments approach to determine the effect of processing parameters on the composition and geometry of Ti-6-4 deposits. The effects of three processing parameters: beam power, translation speed, and wire feed rate, were investigated by varying one while keeping the remaining parameters constant. A three-factorial, three-level, fully balanced mutually orthogonal array (L27) design of experiments approach was used to examine the effects of low, medium, and high settings for the processing parameters on the chemistry, geometry, and quality of the resulting deposits. Single bead high deposits were fabricated and evaluated for 27 experimental conditions. Loss of aluminum in Ti-6-4 was observed in EBF3 processing due to selective vaporization of the aluminum from the sustained molten pool in the vacuum environment; therefore, the chemistries of the deposits were measured and compared with the composition of the initial wire and base plate to determine if the loss of aluminum could be minimized through careful selection of processing parameters. The influence of processing parameters and coupling between these parameters on bulk composition, measured by Direct Current Plasma (DCP), local microchemistries determined by Wavelength Dispersive Spectrometry (WDS), and deposit geometry will also be discussed.

Spatiotemporal dynamics of word retrieval in speech production revealed by cortical high-frequency band activity

PubMed Central

Dhillon, Rummit K.; Clarke, Alex; King-Stephens, David; Laxer, Kenneth D.; Weber, Peter B.; Kuperman, Rachel A.; Auguste, Kurtis I.; Brunner, Peter; Lin, Jack J.; Parvizi, Josef; Crone, Nathan E.; Dronkers, Nina F.; Knight, Robert T.

2017-01-01

Word retrieval is core to language production and relies on complementary processes: the rapid activation of lexical and conceptual representations and word selection, which chooses the correct word among semantically related competitors. Lexical and conceptual activation is measured by semantic priming. In contrast, word selection is indexed by semantic interference and is hampered in semantically homogeneous (HOM) contexts. We examined the spatiotemporal dynamics of these complementary processes in a picture naming task with blocks of semantically heterogeneous (HET) or HOM stimuli. We used electrocorticography data obtained from frontal and temporal cortices, permitting detailed spatiotemporal analysis of word retrieval processes. A semantic interference effect was observed with naming latencies longer in HOM versus HET blocks. Cortical response strength as indexed by high-frequency band (HFB) activity (70–150 Hz) amplitude revealed effects linked to lexical-semantic activation and word selection observed in widespread regions of the cortical mantle. Depending on the subsecond timing and cortical region, HFB indexed semantic interference (i.e., more activity in HOM than HET blocks) or semantic priming effects (i.e., more activity in HET than HOM blocks). These effects overlapped in time and space in the left posterior inferior temporal gyrus and the left prefrontal cortex. The data do not support a modular view of word retrieval in speech production but rather support substantial overlap of lexical-semantic activation and word selection mechanisms in the brain. PMID:28533406

An Examination of the Selection Criteria Used in the Architect-Engineer Selection Process of Air Force Base Civil Engineers.

DTIC Science & Technology

1987-09-01

overall goal of hiring highly qualified firms on a fair basis. In conducting this research and writing its report of findings, I have benefited greatly... it . Introduction................... . . ... .. .. ..... Overview.................. . . ... .. .. ... Background........ ...... .. .. ...... Focus of...the focus of the study, its purpose and justification, its specific objective, and the scope of the study’s application. Background In recent years

Metal separations using aqueous biphasic partitioning systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chaiko, D.J.; Zaslavsky, B.; Rollins, A.N.

1996-05-01

Aqueous biphasic extraction (ABE) processes offer the potential for low-cost, highly selective separations. This countercurrent extraction technique involves selective partitioning of either dissolved solutes or ultrafine particulates between two immiscible aqueous phases. The extraction systems that the authors have studied are generated by combining an aqueous salt solution with an aqueous polymer solution. They have examined a wide range of applications for ABE, including the treatment of solid and liquid nuclear wastes, decontamination of soils, and processing of mineral ores. They have also conducted fundamental studies of solution microstructure using small angle neutron scattering (SANS). In this report they reviewmore » the physicochemical fundamentals of aqueous biphase formation and discuss the development and scaleup of ABE processes for environmental remediation.« less

Nano-encrypted Morse code: a versatile approach to programmable and reversible nanoscale assembly and disassembly.

PubMed

Wong, Ngo Yin; Xing, Hang; Tan, Li Huey; Lu, Yi

2013-02-27

While much work has been devoted to nanoscale assembly of functional materials, selective reversible assembly of components in the nanoscale pattern at selective sites has received much less attention. Exerting such a reversible control of the assembly process will make it possible to fine-tune the functional properties of the assembly and to realize more complex designs. Herein, by taking advantage of different binding affinities of biotin and desthiobiotin toward streptavidin, we demonstrate selective and reversible decoration of DNA origami tiles with streptavidin, including revealing an encrypted Morse code "NANO" and reversible exchange of uppercase letter "I" with lowercase "i". The yields of the conjugations are high (>90%), and the process is reversible. We expect this versatile conjugation technique to be widely applicable with different nanomaterials and templates.

High aspect ratio template and method for producing same

NASA Technical Reports Server (NTRS)

Sakamoto, Jeff S. (Inventor); Weiss, James R. (Inventor); Fleurial, Jean-Pierre (Inventor); Kisor, Adam (Inventor); Tuszynski, Mark (Inventor); Stokols, Shula (Inventor); Holt, Todd Edward (Inventor); Welker, David James (Inventor); Breckon, Christopher David (Inventor)

2010-01-01

Millimeter to nano-scale structures manufactured using a multi-component polymer fiber matrix are disclosed. The use of dissimilar polymers allows the selective dissolution of the polymers at various stages of the manufacturing process. In one application, biocompatible matrixes may be formed with long pore length and small pore size. The manufacturing process begins with a first polymer fiber arranged in a matrix formed by a second polymer fiber. End caps may be attached to provide structural support and the polymer fiber matrix selectively dissolved away leaving only the long polymer fibers. These may be exposed to another product, such as a biocompatible gel to form a biocompatible matrix. The polymer fibers may then be selectively dissolved leaving only a biocompatible gel scaffold with the pores formed by the dissolved polymer fibers.

The impact of dispersion on selective laser melting of titanium and niobium fine powders mixture

NASA Astrophysics Data System (ADS)

Razin, A.; Ovchinnikov, V.; Akhmetshin, R.; Krinitcyn, M.; Fedorov, V.; Akhmetshina, V.

2016-11-01

This paper is dedicated to the study of selective laser melting process of metal powders. Experiments were performed in the Research Center Modern Manufacturing Technologies of TPU with the fine powders of titanium and niobium. The research was carried out on 3D laser printer designed at TPU. In the framework of experiments aimed at determining possibilities of obtaining niobium-titanium alloy by SLS (selective laser sintering) there were studied the basic processes of laser melting and their effect on the quality of final samples and products. We determined operation modes of 3D printers which allow obtaining high quality of printed sample surface. The research results show that rigid requirements related to powder dispersiveness and proportions are needed to achieve better quality of products.

Primer-Free Aptamer Selection Using A Random DNA Library

PubMed Central

Pan, Weihua; Xin, Ping; Patrick, Susan; Dean, Stacey; Keating, Christine; Clawson, Gary

2010-01-01

Aptamers are highly structured oligonucleotides (DNA or RNA) that can bind to targets with affinities comparable to antibodies 1. They are identified through an in vitro selection process called Systematic Evolution of Ligands by EXponential enrichment (SELEX) to recognize a wide variety of targets, from small molecules to proteins and other macromolecules 2-4. Aptamers have properties that are well suited for in vivo diagnostic and/or therapeutic applications: Besides good specificity and affinity, they are easily synthesized, survive more rigorous processing conditions, they are poorly immunogenic, and their relatively small size can result in facile penetration of tissues. Aptamers that are identified through the standard SELEX process usually comprise ~80 nucleotides (nt), since they are typically selected from nucleic acid libraries with ~40 nt long randomized regions plus fixed primer sites of ~20 nt on each side. The fixed primer sequences thus can comprise nearly ~50% of the library sequences, and therefore may positively or negatively compromise identification of aptamers in the selection process 3, although bioinformatics approaches suggest that the fixed sequences do not contribute significantly to aptamer structure after selection 5. To address these potential problems, primer sequences have been blocked by complementary oligonucleotides or switched to different sequences midway during the rounds of SELEX 6, or they have been trimmed to 6-9 nt 7, 8. Wen and Gray 9 designed a primer-free genomic SELEX method, in which the primer sequences were completely removed from the library before selection and were then regenerated to allow amplification of the selected genomic fragments. However, to employ the technique, a unique genomic library has to be constructed, which possesses limited diversity, and regeneration after rounds of selection relies on a linear reamplification step. Alternatively, efforts to circumvent problems caused by fixed primer sequences using high efficiency partitioning are met with problems regarding PCR amplification 10. We have developed a primer-free (PF) selection method that significantly simplifies SELEX procedures and effectively eliminates primer-interference problems 11, 12. The protocols work in a straightforward manner. The central random region of the library is purified without extraneous flanking sequences and is bound to a suitable target (for example to a purified protein or complex mixtures such as cell lines). Then the bound sequences are obtained, reunited with flanking sequences, and re-amplified to generate selected sub-libraries. As an example, here we selected aptamers to S100B, a protein marker for melanoma. Binding assays showed Kd s in the 10-7 - 10-8 M range after a few rounds of selection, and we demonstrate that the aptamers function effectively in a sandwich binding format. PMID:20689511

Breaking cover: neural responses to slow and fast camouflage-breaking motion.

PubMed

Yin, Jiapeng; Gong, Hongliang; An, Xu; Chen, Zheyuan; Lu, Yiliang; Andolina, Ian M; McLoughlin, Niall; Wang, Wei

2015-08-22

Primates need to detect and recognize camouflaged animals in natural environments. Camouflage-breaking movements are often the only visual cue available to accomplish this. Specifically, sudden movements are often detected before full recognition of the camouflaged animal is made, suggesting that initial processing of motion precedes the recognition of motion-defined contours or shapes. What are the neuronal mechanisms underlying this initial processing of camouflaged motion in the primate visual brain? We investigated this question using intrinsic-signal optical imaging of macaque V1, V2 and V4, along with computer simulations of the neural population responses. We found that camouflaged motion at low speed was processed as a direction signal by both direction- and orientation-selective neurons, whereas at high-speed camouflaged motion was encoded as a motion-streak signal primarily by orientation-selective neurons. No population responses were found to be invariant to the camouflage contours. These results suggest that the initial processing of camouflaged motion at low and high speeds is encoded as direction and motion-streak signals in primate early visual cortices. These processes are consistent with a spatio-temporal filter mechanism that provides for fast processing of motion signals, prior to full recognition of camouflage-breaking animals. © 2015 The Authors.

Breaking cover: neural responses to slow and fast camouflage-breaking motion

PubMed Central

Yin, Jiapeng; Gong, Hongliang; An, Xu; Chen, Zheyuan; Lu, Yiliang; Andolina, Ian M.; McLoughlin, Niall; Wang, Wei

2015-01-01

Primates need to detect and recognize camouflaged animals in natural environments. Camouflage-breaking movements are often the only visual cue available to accomplish this. Specifically, sudden movements are often detected before full recognition of the camouflaged animal is made, suggesting that initial processing of motion precedes the recognition of motion-defined contours or shapes. What are the neuronal mechanisms underlying this initial processing of camouflaged motion in the primate visual brain? We investigated this question using intrinsic-signal optical imaging of macaque V1, V2 and V4, along with computer simulations of the neural population responses. We found that camouflaged motion at low speed was processed as a direction signal by both direction- and orientation-selective neurons, whereas at high-speed camouflaged motion was encoded as a motion-streak signal primarily by orientation-selective neurons. No population responses were found to be invariant to the camouflage contours. These results suggest that the initial processing of camouflaged motion at low and high speeds is encoded as direction and motion-streak signals in primate early visual cortices. These processes are consistent with a spatio-temporal filter mechanism that provides for fast processing of motion signals, prior to full recognition of camouflage-breaking animals. PMID:26269500

PREPARATION OF HIGH PURITY UF$sub 4$

DOEpatents

Magner, J.E.; Long, R.S.; Ellis, D.A.; Grinstead, R.R.

1962-04-17

S>A process for preparing very highly pure uranous tetrafluoride from impure uranium laden solvent extraction strip solutions, ion exchange process and resin-inpulp process eluate solutions which are at least 8M in hydrochloric acid is described. The process first comprises treating any of the above-mentioned solutions with a reducing agent to reduce the uranium to the + 4 oxidation state, and then contacting the reduced solution with an extractant phase comprising about 10 to 70% of tri-butyl phosphate in an organic solvent-diluent selected from benzene, ethyl-benzene, chlorobenzene, xylene, kerosene, or the like. The uranium is extracted into the extractant phase and is subsequently precipitated by treating the extractant with an aqueous fluoride solution. The highly pure uranous tetrafluoride precipitate is separated from the phases and recovered for subsequent utilization. (AEC)

The Ecology and Evolution of Cancer: The Ultra-Microevolutionary Process.

PubMed

Wu, Chung-I; Wang, Hurng-Yi; Ling, Shaoping; Lu, Xuemei

2016-11-23

Although tumorigenesis has been accepted as an evolutionary process ( 20 , 102 ), many forces may operate differently in cancers than in organisms, as they evolve at vastly different time scales. Among such forces, natural selection, here defined as differential cellular proliferation among distinct somatic cell genotypes, is particularly interesting because its action might be thwarted in multicellular organisms ( 20 , 29 ). In this review, selection is analyzed in two stages of cancer evolution: Stage I is the evolution between tumors and normal tissues, and Stage II is the evolution within tumors. The Cancer Genome Atlas (TCGA) data show a low degree of convergent evolution in Stage I, where genetic changes are not extensively shared among cases. An equally important, albeit much less highlighted, discovery using TCGA data is that there is almost no net selection in cancer evolution. Both positive and negative selection are evident but they neatly cancel each other out, rendering total selection ineffective in the absence of recombination. The efficacy of selection is even lower in Stage II, where neutral (non-Darwinian) evolution is increasingly supported by high-density sampling studies ( 81 , 123 ). Because natural selection is not a strong deterministic force, cancers usually evolve divergently even in similar tissue environments.

Thermoregulatory performance and habitat selection of the eastern box turtle (Terrapene carolina carolina)

PubMed Central

Parlin, Adam F; do Amaral, José Pedro S; Dougherty, John Kelly; Stevens, M Henry H

2017-01-01

Abstract Environmental conditions may affect individual physiological processes that influence short-term performance and ultimately growth, survival and reproduction. As such, habitats selected by animals must provide suitable and adequate resources. Ectothermic species are highly dependent on climatic conditions and ambient temperatures that dictate body temperature regulation and in turn physiological processes. We investigated the thermoregulatory performance, habitat selection, and movements of an ectothermic vertebrate, the Eastern box turtle (Terrapene carolina carolina) to assess the importance of thermoregulatory physiology in habitat selection. We evaluated the relationship between habitat selection and thermoregulatory performance in Southwest Ohio over two active seasons from May until October. We found that T. carolina selected shaded habitats, including evergreen and deciduous forests, as well as herbaceous grasslands, conformed to the ambient temperatures throughout the active season, although these habitats had temperatures below those expected based on thermal optima of box turtles. Further, we found that movement was not correlated with internal body temperature. Our study shows that thermal conditions are not paramount in habitat selection of box turtles, but that cooler temperatures do not have an effect on the extent of their locomotion. PMID:29255608

Joint ventures: to pursue or not to pursue?

PubMed

Blaszyk, Michael D; Hill-Mischel, Jody

2007-11-01

Hospitals should carefully select joint venture partners. The joint venture evaluation process should involve a high-level screen of strategic opportunities. Hospitals should develop a full business plan for the joint venture.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fu, Jiayi; Vasiliadou, Efterpi S.; Goulas, Konstantinos A.

A novel one-step process for the selective production of succinic acid from tartaric acid is developed. High succinic yield is achieved in an efficient catalytic system comprised of MoO x/BC, HBr and acetic acid under hydrogen atmosphere.

Comparison of lignin extraction processes: Economic and environmental assessment.

PubMed

Carvajal, Juan C; Gómez, Álvaro; Cardona, Carlos A

2016-08-01

This paper presents the technical-economic and environmental assessment of four lignin extraction processes from two different raw materials (sugarcane bagasse and rice husks). The processes are divided into two categories, the first processes evaluates lignin extraction with prior acid hydrolysis step, while in the second case the extraction processes are evaluated standalone for a total analysis of 16 scenarios. Profitability indicators as the net present value (NPV) and environmental indicators as the potential environmental impact (PEI) are used through a process engineering approach to understand and select the best lignin extraction process. The results show that both economically and environmentally process with sulfites and soda from rice husk presents the best results; however the quality of lignin obtained with sulfites is not suitable for high value-added products. Then, the soda is an interesting option for the extraction of lignin if high quality lignin is required for high value-added products at low costs. Copyright © 2016 Elsevier Ltd. All rights reserved.

Selection of High Temperature Organic Materials for Future Stirling Convertors

NASA Technical Reports Server (NTRS)

Shin, Euy-Sik Eugene

2017-01-01

In the future higher temperature Stirling convertors for improved efficiency and performance, various high temperature organic materials have been demanded as essential components for their unique properties and functions such as bonding, potting, sealing, thread locking, insulation, and lubrication. The higher temperature capabilities would also allow current state-of-the-art (SOA) convertors to be used in additional missions, particularly those that require a Venus flyby for a gravity assist. Stirling convertor radioisotope generators have been developed for potential future space applications including Lunar/Mars surface power or a variety of spacecraft and vehicles, especially with a long mission cycle, sometimes up to 17 years, such as deep space exploration. Thus, performance, durability, and reliability of the organics should be critically evaluated in terms of comprehensive structure-process-service environment relations based on the potential mission specifications. The initial efforts in screening the high temperature candidates focused on the most susceptible organics, such as adhesive, potting compound, o-ring, shrink tubing, and thread locker materials in conjunction with commercially available materials. More systematic and practical test methodologies that were developed and optimized based on the extensive organic evaluations and validations performed for various Stirling convertor types were employed to determine thermal stability, outgassing, and material compatibility of the selected organic candidates against their functional requirements. Processing and fabrication conditions and procedures were also optimized. This paper presents results of the three-step candidate evaluation processes, their application limitations, and the final selection recommendations.

Fluvial processes in Ma'adim Vallis and the potential of Gusev crater as a high priority site

NASA Technical Reports Server (NTRS)

Cabrol, Nathalie; Landheim, Ragnild; Greeley, Ronald; Farmer, Jack

1994-01-01

According to exobiology site selection criteria for Mars, the search for potential extinct/extant water dependent life should focus on sites were water flowed and ponded. The Ma'adim Vallis/Gusev crater system is of high priority for exobiology research, because it appears to have involved long term flooding, different periods and rates of sedimentation, and probable episodic ponding. The topics covered include the following: evidence of nonuniform fluvial processes and early overflooding of the plateau and ponding.

Static and dynamic high power, space nuclear electric generating systems

NASA Technical Reports Server (NTRS)

Wetch, J. R.; Begg, L. L.; Koester, J. K.

1985-01-01

Space nuclear electric generating systems concepts have been assessed for their potential in satisfying future spacecraft high power (several megawatt) requirements. Conceptual designs have been prepared for reactor power systems using the most promising static (thermionic) and the most promising dynamic conversion processes. Component and system layouts, along with system mass and envelope requirements have been made. Key development problems have been identified and the impact of the conversion process selection upon thermal management and upon system and vehicle configuration is addressed.

Inducing Stable α + β Microstructures during Selective Laser Melting of Ti-6Al-4V Using Intensified Intrinsic Heat Treatments

PubMed Central

Barriobero-Vila, Pere; Gussone, Joachim; Haubrich, Jan; Sandlöbes, Stefanie; Da Silva, Julio Cesar; Cloetens, Peter; Schell, Norbert; Requena, Guillermo

2017-01-01

Selective laser melting is a promising powder-bed-based additive manufacturing technique for titanium alloys: near net-shaped metallic components can be produced with high resource-efficiency and cost savings. For the most commercialized titanium alloy, namely Ti-6Al-4V, the complicated thermal profile of selective laser melting manufacturing (sharp cycles of steep heating and cooling rates) usually hinders manufacturing of components in a one-step process owing to the formation of brittle martensitic microstructures unsuitable for structural applications. In this work, an intensified intrinsic heat treatment is applied during selective laser melting of Ti-6Al-4V powder using a scanning strategy that combines porosity-optimized processing with a very tight hatch distance. Extensive martensite decomposition providing a uniform, fine lamellar α + β microstructure is obtained along the building direction. Moreover, structural evidence of the formation of the intermetallic α2-Ti3Al phase is provided. Variations in the lattice parameter of β serve as an indicator of the microstructural degree of stabilization. Interconnected 3D networks of β are generated in regions highly affected by the intensified intrinsic heat treatment applied. The results obtained reflect a contribution towards simultaneous selective laser melting-manufacturing and heat treatment for fabrication of Ti-6Al-4V parts. PMID:28772630

Selection criteria for wear resistant powder coatings under extreme erosive wear conditions

NASA Astrophysics Data System (ADS)

Kulu, P.; Pihl, T.

2002-12-01

Wear-resistant thermal spray coatings for sliding wear are hard but brittle (such as carbide and oxide based coatings), which makes them useless under impact loading conditions and sensitive to fatigue. Under extreme conditions of erosive wear (impact loading, high hardness of abrasives, and high velocity of abradant particles), composite coatings ensure optimal properties of hardness and toughness. The article describes tungsten carbide-cobalt (WC-Co) systems and self-fluxing alloys, containing tungsten carbide based hardmetal particles [NiCrSiB-(WC-Co)] deposited by the detonation gun, continuous detonation spraying, and spray fusion processes. Different powder compositions and processes were studied, and the effect of the coating structure and wear parameters on the wear resistance of coatings are evaluated. The dependence of the wear resistance of sprayed and fused coatings on their hardness is discussed, and hardness criteria for coating selection are proposed. The so-called “double cemented” structure of WC-Co based hardmetal or metal matrix composite coatings, as compared with a simple cobalt matrix containing particles of WC, was found optimal. Structural criteria for coating selection are provided. To assist the end user in selecting an optimal deposition method and materials, coating selection diagrams of wear resistance versus hardness are given. This paper also discusses the cost-effectiveness of coatings in the application areas that are more sensitive to cost, and composite coatings based on recycled materials are offered.

Working memory and the strategic control of attention in older and younger adults.

PubMed

Hayes, Melissa G; Kelly, Andrew J; Smith, Anderson D

2013-03-01

The objective of this study was to investigate the effects of aging on the strategic control of attention and the extent to which this relationship is mediated by working memory capacity (WMC). This study also sought to investigate boundary conditions wherein age differences in selectivity may occur. Across 2 studies, the value-directed remembering task used by Castel and colleagues (Castel, A. D., Balota, D. A., & McCabe, D. P. (2009). Memory efficiency and the strategic control of attention at encoding: Impairments of value-directed remembering in Alzheimer's Disease. Neuropsychology, 23, 297-306) was modified to include value-directed forgetting. Study 2 incorporated valence as an additional task demand, and age differences were predicted in both studies due to increased demands of controlled processing. Automated operation span and Stroop span were included as working memory measures, and working memory was predicted to mediate performance. Results confirmed these predictions, as older adults were less efficient in maximizing selectivity scores when high demands were placed on selectivity processes, and working memory was found to mediate performance on this task. When list length was increased from previous studies and participants were required to actively forget negative-value words, older adults were not able to selectively encode high-value information to the same degree as younger adults. Furthermore, WMC appears to support the ability to selectively encode information.

Antibiotic free selection for the high level biosynthesis of a silk-elastin-like protein

PubMed Central

Barroca, Mário; Rodrigues, Paulo; Sobral, Rómulo; Costa, M. Manuela R.; Chaves, Susana R.; Machado, Raul; Casal, Margarida; Collins, Tony

2016-01-01

Silk-elastin-like proteins (SELPs) are a family of genetically engineered recombinant protein polymers exhibiting mechanical and biological properties suited for a wide range of applications in the biomedicine and materials fields. They are being explored as the next generation of biomaterials but low productivities and use of antibiotics during production undermine their economic viability and safety. We have developed an industrially relevant, scalable, fed-batch process for the high level production of a novel SELP in E. coli in which the commonly used antibiotic selection marker of the expression vector is exchanged for a post segregational suicide system, the separate-component-stabilisation system (SCS). SCS significantly augments SELP productivity but also enhances the product safety profile and reduces process costs by eliminating the use of antibiotics. Plasmid content increased following induction but no significant differences in plasmid levels were discerned when using SCS or the antibiotic selection markers under the controlled fed-batch conditions employed. It is suggested that the absence of competing plasmid-free cells improves host cell viability and enables increased productivity with SCS. With the process developed, 12.8 g L−1 purified SELP was obtained, this is the highest SELP productivity reported to date and clearly demonstrates the commercial viability of these promising polymers. PMID:27982135

Genes uniquely expressed in human growth plate chondrocytes uncover a distinct regulatory network.

PubMed

Li, Bing; Balasubramanian, Karthika; Krakow, Deborah; Cohn, Daniel H

2017-12-20

Chondrogenesis is the earliest stage of skeletal development and is a highly dynamic process, integrating the activities and functions of transcription factors, cell signaling molecules and extracellular matrix proteins. The molecular mechanisms underlying chondrogenesis have been extensively studied and multiple key regulators of this process have been identified. However, a genome-wide overview of the gene regulatory network in chondrogenesis has not been achieved. In this study, employing RNA sequencing, we identified 332 protein coding genes and 34 long non-coding RNA (lncRNA) genes that are highly selectively expressed in human fetal growth plate chondrocytes. Among the protein coding genes, 32 genes were associated with 62 distinct human skeletal disorders and 153 genes were associated with skeletal defects in knockout mice, confirming their essential roles in skeletal formation. These gene products formed a comprehensive physical interaction network and participated in multiple cellular processes regulating skeletal development. The data also revealed 34 transcription factors and 11,334 distal enhancers that were uniquely active in chondrocytes, functioning as transcriptional regulators for the cartilage-selective genes. Our findings revealed a complex gene regulatory network controlling skeletal development whereby transcription factors, enhancers and lncRNAs participate in chondrogenesis by transcriptional regulation of key genes. Additionally, the cartilage-selective genes represent candidate genes for unsolved human skeletal disorders.

The onset of an eruption: selective assimilation of hydrothermal minerals during pre-eruptive magma ascent of the 2010 summit eruption of Eyjafjallajökull volcano, Iceland

NASA Astrophysics Data System (ADS)

Pistolesi, M.; Cioni, R.; Francalanci, L.; Bertagnini, A.; D'Oriano, C.; Braschi, E.; Höskuldsson, A.

2016-11-01

The complex processes occurring in the initial phases of an eruption are often recorded in the products of its opening stage, which are usually characterized by small volume and limited dispersal, and thus generally poorly studied. The 2010 eruption of Eyjafjallajökull (Iceland) represents a unique opportunity for these investigations thanks to the good preservation of tephra deposits within the ice/snow pack. A detailed geochemical investigation on the glassy groundmass of single ash clasts disclosed a population of fragments with unusual high 87Sr/86Sr (up to 0.70668) for Icelandic magmatism, and anomalous elemental composition with respect to most of the juvenile material of the eruption. This suggests that during its rise, before intruding into the ice cover, magma at a dyke tip selectively assimilated hydrothermal minerals with seawater-related, high-Sr isotopic ratios (zeolites, silica phases, anhydrite) hosted in altered volcanic/epiclastic rocks. According to the observed precursory seismicity, only restricted to few hours before the onset of the eruption, this process could have accompanied subcritical aseismic fracture opening during the days before the eruption, possibly related to stress corrosion-cracking processes, which enhanced the partial dissolution/melting and subsequent selective assimilation of the host rocks.

Olfactory Bulb Deep Short-Axon Cells Mediate Widespread Inhibition of Tufted Cell Apical Dendrites

PubMed Central

LaRocca, Greg

2017-01-01

In the main olfactory bulb (MOB), the first station of sensory processing in the olfactory system, GABAergic interneuron signaling shapes principal neuron activity to regulate olfaction. However, a lack of known selective markers for MOB interneurons has strongly impeded cell-type-selective investigation of interneuron function. Here, we identify the first selective marker of glomerular layer-projecting deep short-axon cells (GL-dSACs) and investigate systematically the structure, abundance, intrinsic physiology, feedforward sensory input, neuromodulation, synaptic output, and functional role of GL-dSACs in the mouse MOB circuit. GL-dSACs are located in the internal plexiform layer, where they integrate centrifugal cholinergic input with highly convergent feedforward sensory input. GL-dSAC axons arborize extensively across the glomerular layer to provide highly divergent yet selective output onto interneurons and principal tufted cells. GL-dSACs are thus capable of shifting the balance of principal tufted versus mitral cell activity across large expanses of the MOB in response to diverse sensory and top-down neuromodulatory input. SIGNIFICANCE STATEMENT The identification of cell-type-selective molecular markers has fostered tremendous insight into how distinct interneurons shape sensory processing and behavior. In the main olfactory bulb (MOB), inhibitory circuits regulate the activity of principal cells precisely to drive olfactory-guided behavior. However, selective markers for MOB interneurons remain largely unknown, limiting mechanistic understanding of olfaction. Here, we identify the first selective marker of a novel population of deep short-axon cell interneurons with superficial axonal projections to the sensory input layer of the MOB. Using this marker, together with immunohistochemistry, acute slice electrophysiology, and optogenetic circuit mapping, we reveal that this novel interneuron population integrates centrifugal cholinergic input with broadly tuned feedforward sensory input to modulate principal cell activity selectively. PMID:28003347

Word learning emerges from the interaction of online referent selection and slow associative learning.

PubMed

McMurray, Bob; Horst, Jessica S; Samuelson, Larissa K

2012-10-01

Classic approaches to word learning emphasize referential ambiguity: In naming situations, a novel word could refer to many possible objects, properties, actions, and so forth. To solve this, researchers have posited constraints, and inference strategies, but assume that determining the referent of a novel word is isomorphic to learning. We present an alternative in which referent selection is an online process and independent of long-term learning. We illustrate this theoretical approach with a dynamic associative model in which referent selection emerges from real-time competition between referents and learning is associative (Hebbian). This model accounts for a range of findings including the differences in expressive and receptive vocabulary, cross-situational learning under high degrees of ambiguity, accelerating (vocabulary explosion) and decelerating (power law) learning, fast mapping by mutual exclusivity (and differences in bilinguals), improvements in familiar word recognition with development, and correlations between speed of processing and learning. Together it suggests that (a) association learning buttressed by dynamic competition can account for much of the literature; (b) familiar word recognition is subserved by the same processes that identify the referents of novel words (fast mapping); (c) online competition may allow the children to leverage information available in the task to augment performance despite slow learning; (d) in complex systems, associative learning is highly multifaceted; and (e) learning and referent selection, though logically distinct, can be subtly related. It suggests more sophisticated ways of describing the interaction between situation- and developmental-time processes and points to the need for considering such interactions as a primary determinant of development. PsycINFO Database Record (c) 2012 APA, all rights reserved.

Energy-Efficient Bioalcohol Recovery by Gel Stripping

NASA Astrophysics Data System (ADS)

Godbole, Rutvik; Ma, Lan; Hedden, Ronald

2014-03-01

Design of energy-efficient processes for recovering butanol and ethanol from dilute fermentations is a key challenge facing the biofuels industry due to the high energy consumption of traditional multi-stage distillation processes. Gel stripping is an alternative purification process by which a dilute alcohol is stripped from the fermentation product by passing it through a packed bed containing particles of a selectively absorbent polymeric gel material. The gel must be selective for the alcohol, while swelling to a reasonable degree in dilute alcohol-water mixtures. To accelerate materials optimization, a combinatorial approach is taken to screen a matrix of copolymer gels having orthogonal gradients in crosslinker concentration and hydrophilicity. Using a combination of swelling in pure solvents, the selectivity and distribution coefficients of alcohols in the gels can be predicted based upon multi-component extensions of Flory-Rehner theory. Predictions can be validated by measuring swelling in water/alcohol mixtures and conducting h HPLC analysis of the external liquid. 95% + removal of butanol from dilute aqueous solutions has been demonstrated, and a mathematical model of the unsteady-state gel stripping process has been developed. NSF CMMI Award 1335082.

How Do I Get In? Criteria Shaping the High School Course Recommendation Process

ERIC Educational Resources Information Center

Bernhardt, Philip Evan

2014-01-01

Academic tracking is a common practice in American high schools. While its impact on the lives of teachers and students is well documented, few studies pay close attention to the criteria used to determine high school students' academic trajectories or how teachers select and apply these criteria. This review, which examines the types of…

Anxiety and the Processing of Emotionally Threatening Stimuli: Distinctive Patterns of Selective Attention among High- and Low-Test-Anxious Children.

ERIC Educational Resources Information Center

Vasey, Michael W.; And Others

1996-01-01

Tested for bias toward shifting attention toward threatening stimuli among high-anxious children and away from such stimuli among low-anxious children, ages 11-14. Results supported the predicted attentional bias toward threat cues among high-test-anxious children. Unexpectedly, the predicted attentional bias away from threat cues among…

The proactive brain and the fate of dead hypotheses

PubMed Central

Tal, Amir; Bar, Moshe

2014-01-01

A substantial portion of information flow in the brain is directed top-down, from high processing areas downwards. Signals of this sort are regarded as conveying prior expectations, biasing the processing and eventual perception of incoming stimuli. In this perspective we describe a framework of top-down processing in the visual system in which predictions on the identity of objects in sight aid in their recognition. Focus is placed, in particular, on a relatively uncharted ramification of this framework, that of the fate of initial predictions that are eventually rejected during the process of selection. We propose that such predictions are rapidly inhibited in the brain after a competing option has been selected. Empirical support, along with behavioral, neuronal and computational aspects of this proposal are discussed, and future directions for related research are offered. PMID:25408645

The proactive brain and the fate of dead hypotheses.

PubMed

Tal, Amir; Bar, Moshe

2014-01-01

A substantial portion of information flow in the brain is directed top-down, from high processing areas downwards. Signals of this sort are regarded as conveying prior expectations, biasing the processing and eventual perception of incoming stimuli. In this perspective we describe a framework of top-down processing in the visual system in which predictions on the identity of objects in sight aid in their recognition. Focus is placed, in particular, on a relatively uncharted ramification of this framework, that of the fate of initial predictions that are eventually rejected during the process of selection. We propose that such predictions are rapidly inhibited in the brain after a competing option has been selected. Empirical support, along with behavioral, neuronal and computational aspects of this proposal are discussed, and future directions for related research are offered.

Process for selecting engineering tools : applied to selecting a SysML tool.

DOE Office of Scientific and Technical Information (OSTI.GOV)

De Spain, Mark J.; Post, Debra S.; Taylor, Jeffrey L.

2011-02-01

Process for Selecting Engineering Tools outlines the process and tools used to select a SysML (Systems Modeling Language) tool. The process is general in nature and users could use the process to select most engineering tools and software applications.

Child Care Decision Making: Understanding Priorities and Processes Used by Low-Income Families in Minnesota

ERIC Educational Resources Information Center

Forry, Nicole; Isner, Tabitha K.; Daneri, Maria P.; Tout, Kathryn

2014-01-01

Research Findings: Few studies have described parents' child care decision-making process, yet understanding how parents make child care choices is fundamental to developing effective services to promote the selection of high-quality care. This study used latent profile analysis to distinguish subgroups of low-income parents identified as having…

Examining High-Performing Education Systems in Terms of Teacher Training: Lessons Learnt for Low-Performers

ERIC Educational Resources Information Center

Çer, Erkan; Solak, Ekrem

2018-01-01

The quality of a teacher plays one of the most important roles in the achievement of an education system. Teacher training is a multi-dimensional process which comprises the selection of teacher candidates, pre-service training, appointment, in-service training and teaching practices. Therefore, this study focuses on teacher training processes in…

Disruptive chemicals, senescence and immortality

PubMed Central

Carnero, Amancio; Blanco-Aparicio, Carmen; Kondoh, Hiroshi; Lleonart, Matilde E.; Martinez-Leal, Juan Fernando; Mondello, Chiara; Ivana Scovassi, A.; Bisson, William H.; Amedei, Amedeo; Roy, Rabindra; Woodrick, Jordan; Colacci, Annamaria; Vaccari, Monica; Raju, Jayadev; Al-Mulla, Fahd; Al-Temaimi, Rabeah; Salem, Hosni K.; Memeo, Lorenzo; Forte, Stefano; Singh, Neetu; Hamid, Roslida A.; Ryan, Elizabeth P.; Brown, Dustin G.; Wise, John Pierce; Wise, Sandra S.; Yasaei, Hemad

2015-01-01

Carcinogenesis is thought to be a multistep process, with clonal evolution playing a central role in the process. Clonal evolution involves the repeated ‘selection and succession’ of rare variant cells that acquire a growth advantage over the remaining cell population through the acquisition of ‘driver mutations’ enabling a selective advantage in a particular micro-environment. Clonal selection is the driving force behind tumorigenesis and possesses three basic requirements: (i) effective competitive proliferation of the variant clone when compared with its neighboring cells, (ii) acquisition of an indefinite capacity for self-renewal, and (iii) establishment of sufficiently high levels of genetic and epigenetic variability to permit the emergence of rare variants. However, several questions regarding the process of clonal evolution remain. Which cellular processes initiate carcinogenesis in the first place? To what extent are environmental carcinogens responsible for the initiation of clonal evolution? What are the roles of genotoxic and non-genotoxic carcinogens in carcinogenesis? What are the underlying mechanisms responsible for chemical carcinogen-induced cellular immortality? Here, we explore the possible mechanisms of cellular immortalization, the contribution of immortalization to tumorigenesis and the mechanisms by which chemical carcinogens may contribute to these processes. PMID:26106138

A Semiautomated Framework for Integrating Expert Knowledge into Disease Marker Identification

DOE PAGES

Wang, Jing; Webb-Robertson, Bobbie-Jo M.; Matzke, Melissa M.; ...

2013-01-01

Background . The availability of large complex data sets generated by high throughput technologies has enabled the recent proliferation of disease biomarker studies. However, a recurring problem in deriving biological information from large data sets is how to best incorporate expert knowledge into the biomarker selection process. Objective . To develop a generalizable framework that can incorporate expert knowledge into data-driven processes in a semiautomated way while providing a metric for optimization in a biomarker selection scheme. Methods . The framework was implemented as a pipeline consisting of five components for the identification of signatures from integrated clustering (ISIC). Expertmore » knowledge was integrated into the biomarker identification process using the combination of two distinct approaches; a distance-based clustering approach and an expert knowledge-driven functional selection. Results . The utility of the developed framework ISIC was demonstrated on proteomics data from a study of chronic obstructive pulmonary disease (COPD). Biomarker candidates were identified in a mouse model using ISIC and validated in a study of a human cohort. Conclusions . Expert knowledge can be introduced into a biomarker discovery process in different ways to enhance the robustness of selected marker candidates. Developing strategies for extracting orthogonal and robust features from large data sets increases the chances of success in biomarker identification.« less

A Semiautomated Framework for Integrating Expert Knowledge into Disease Marker Identification

PubMed Central

Wang, Jing; Webb-Robertson, Bobbie-Jo M.; Matzke, Melissa M.; Varnum, Susan M.; Brown, Joseph N.; Riensche, Roderick M.; Adkins, Joshua N.; Jacobs, Jon M.; Hoidal, John R.; Scholand, Mary Beth; Pounds, Joel G.; Blackburn, Michael R.; Rodland, Karin D.; McDermott, Jason E.

2013-01-01

Background. The availability of large complex data sets generated by high throughput technologies has enabled the recent proliferation of disease biomarker studies. However, a recurring problem in deriving biological information from large data sets is how to best incorporate expert knowledge into the biomarker selection process. Objective. To develop a generalizable framework that can incorporate expert knowledge into data-driven processes in a semiautomated way while providing a metric for optimization in a biomarker selection scheme. Methods. The framework was implemented as a pipeline consisting of five components for the identification of signatures from integrated clustering (ISIC). Expert knowledge was integrated into the biomarker identification process using the combination of two distinct approaches; a distance-based clustering approach and an expert knowledge-driven functional selection. Results. The utility of the developed framework ISIC was demonstrated on proteomics data from a study of chronic obstructive pulmonary disease (COPD). Biomarker candidates were identified in a mouse model using ISIC and validated in a study of a human cohort. Conclusions. Expert knowledge can be introduced into a biomarker discovery process in different ways to enhance the robustness of selected marker candidates. Developing strategies for extracting orthogonal and robust features from large data sets increases the chances of success in biomarker identification. PMID:24223463

A Semiautomated Framework for Integrating Expert Knowledge into Disease Marker Identification

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Jing; Webb-Robertson, Bobbie-Jo M.; Matzke, Melissa M.

2013-10-01

Background. The availability of large complex data sets generated by high throughput technologies has enabled the recent proliferation of disease biomarker studies. However, a recurring problem in deriving biological information from large data sets is how to best incorporate expert knowledge into the biomarker selection process. Objective. To develop a generalizable framework that can incorporate expert knowledge into data-driven processes in a semiautomated way while providing a metric for optimization in a biomarker selection scheme. Methods. The framework was implemented as a pipeline consisting of five components for the identification of signatures from integrated clustering (ISIC). Expert knowledge was integratedmore » into the biomarker identification process using the combination of two distinct approaches; a distance-based clustering approach and an expert knowledge-driven functional selection. Results. The utility of the developed framework ISIC was demonstrated on proteomics data from a study of chronic obstructive pulmonary disease (COPD). Biomarker candidates were identified in a mouse model using ISIC and validated in a study of a human cohort. Conclusions. Expert knowledge can be introduced into a biomarker discovery process in different ways to enhance the robustness of selected marker candidates. Developing strategies for extracting orthogonal and robust features from large data sets increases the chances of success in biomarker identification.« less

Controlled catalytic and thermal sequential pyrolysis and hydrolysis of mixed polymer waste streams to sequentially recover monomers or other high value products

DOEpatents

Evans, R.J.; Chum, H.L.

1994-10-25

A process of using fast pyrolysis in a carrier gas to convert a plastic waste feedstream having a mixed polymeric composition in a manner such that pyrolysis of a given polymer to its high value monomeric constituent occurs prior to pyrolysis of other plastic components therein comprising: selecting a first temperature program range to cause pyrolysis of said given polymer to its high value monomeric constituent prior to a temperature range that causes pyrolysis of other plastic components; selecting a catalyst and support for treating said feed streams with said catalyst to effect acid or base catalyzed reaction pathways to maximize yield or enhance separation of said high value monomeric constituent in said temperature program range; differentially heating said feed stream at a heat rate within the first temperature program range to provide differential pyrolysis for selective recovery of optimum quantities of the high value monomeric constituent prior to pyrolysis of other plastic components; separating the high value monomeric constituents; selecting a second higher temperature range to cause pyrolysis of a different high value monomeric constituent of said plastic waste and differentially heating the feedstream at the higher temperature program range to cause pyrolysis of the different high value monomeric constituent; and separating the different high value monomeric constituent. 83 figs.

Controlled catalytic and thermal sequential pyrolysis and hydrolysis of polymer waste comprising nylon 6 and a polyolefin or mixtures of polyolefins to sequentially recover monomers or other high value products

DOEpatents

Evans, Robert J.; Chum, Helena L.

1994-01-01

A process of using fast pyrolysis in a carrier gas to convert a plastic waste feedstream having a mixed polymeric composition in a manner such that pyrolysis of a given polymer to its high value monomeric constituent occurs prior to pyrolysis of other plastic components therein comprising: selecting a first temperature program range to cause pyrolysis of said given polymer to its high value monomeric constituent prior to a temperature range that causes pyrolysis of other plastic components; selecting a catalyst and support for treating said feed streams with said catalyst to effect acid or base catalyzed reaction pathways to maximize yield or enhance separation of said high value monomeric constituent in said temperature program range; differentially heating said feed stream at a heat rate within the first temperature program range to provide differential pyrolysis for selective recovery of optimum quantities of the high value monomeric constituent prior to pyrolysis of other plastic components; separating the high value monomeric constituents; selecting a second higher temperature range to cause pyrolysis of a different high value monomeric constituent of said plastic waste and differentially heating the feedstream at the higher temperature program range to cause pyrolysis of the different high value monomeric constituent; and separating the different high value monomeric constituent.

Controlled catalytic and thermal sequential pyrolysis and hydrolysis of mixed polymer waste streams to sequentially recover monomers or other high value products

DOEpatents

Evans, R.J.; Chum, H.L.

1994-04-05

A process is described for using fast pyrolysis in a carrier gas to convert a plastic waste feedstream having a mixed polymeric composition in a manner such that pyrolysis of a given polymer to its high value monomeric constituent occurs prior to pyrolysis of other plastic components therein comprising: selecting a first temperature program range to cause pyrolysis of said given polymer to its high value monomeric constituent prior to a temperature range that causes pyrolysis of other plastic components; selecting a catalyst and support for treating said feed streams with said catalyst to effect acid or base catalyzed reaction pathways to maximize yield or enhance separation of said high value monomeric constituent in said temperature program range; differentially heating said feed stream at a heat rate within the first temperature program range to provide differential pyrolysis for selective recovery of optimum quantities of the high value monomeric constituent prior to pyrolysis of other plastic components; separating the high value monomeric constituents, selecting a second higher temperature range to cause pyrolysis of a different high value monomeric constituent of said plastic waste and differentially heating the feedstream at the higher temperature program range to cause pyrolysis of the different high value monomeric constituent; and separating the different high value monomeric constituent. 87 figures.

Controlled catalytic and thermal sequential pyrolysis and hydrolysis of polymer waste comprising nylon 6 and a polyolefin or mixtures of polyolefins to sequentially recover monomers or other high value products

DOEpatents

Evans, R.J.; Chum, H.L.

1994-10-25

A process of using fast pyrolysis in a carrier gas to convert a plastic waste feedstream having a mixed polymeric composition in a manner such that pyrolysis of a given polymer to its high value monomeric constituent occurs prior to pyrolysis of other plastic components therein comprising: selecting a first temperature program range to cause pyrolysis of said given polymer to its high value monomeric constituent prior to a temperature range that causes pyrolysis of other plastic components; selecting a catalyst and support for treating said feed streams with said catalyst to effect acid or base catalyzed reaction pathways to maximize yield or enhance separation of said high value monomeric constituent in said temperature program range; differentially heating said feed stream at a heat rate within the first temperature program range to provide differential pyrolysis for selective recovery of optimum quantities of the high value monomeric constituent prior to pyrolysis of other plastic components; separating the high value monomeric constituents; selecting a second higher temperature range to cause pyrolysis of a different high value monomeric constituent of said plastic waste and differentially heating the feedstream at the higher temperature program range to cause pyrolysis of the different high value monomeric constituent; and separating the different high value monomeric constituent. 83 figs.

AOI [3] High-Temperature Nano-Derived Micro-H 2 and - H 2S Sensors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sabolsky, Edward M.

2014-08-01

The emissions from coal-fired power plants remain a significant concern for air quality. This environmental challenge must be overcome by controlling the emission of sulfur dioxide (SO 2) and hydrogen sulfide (H 2S) throughout the entire coal combustion process. One of the processes which could specifically benefit from robust, low cost, and high temperature compatible gas sensors is the coal gasification process which converts coal and/or biomass into syngas. Hydrogen (H 2), carbon monoxide (CO) and sulfur compounds make up 33%, 43% and 2% of syngas, respectively. Therefore, development of a high temperature (>500°C) chemical sensor for in-situ monitoring ofmore » H 2, H 2S and SO2 2 levels during coal gasification is strongly desired. The selective detection of SO 2/H 2S in the presence of H 2, is a formidable task for a sensor designer. In order to ensure effective operation of these chemical sensors, the sensor system must inexpensively function within harsh temperature and chemical environment. Currently available sensing approaches, which are based on gas chromatography, electrochemistry, and IR-spectroscopy, do not satisfy the required cost and performance targets. This work focused on the development microsensors that can be applied to this application. In order to develop the high- temperature compatible microsensor, this work addressed various issues related to sensor stability, selectivity, and miniaturization. In the research project entitled “High-Temperature Nano-Derived Micro-H 2 and -H 2S Sensors”, the team worked to develop micro-scale, chemical sensors and sensor arrays composed of nano-derived, metal-oxide composite materials to detect gases like H 2, SO 2, and H 2S within high-temperature environments (>500°C). The research was completed in collaboration with NexTech Materials, Ltd. (Lewis Center, Ohio). NexTech assisted in the testing of the sensors in syngas with contaminate levels of H 2S. The idea of including nanomaterials as the sensing material within resistive-type chemical sensor platforms was to increase the sensitivity (as shown for room temperature applications). Unfortunately, nanomaterials are not stable at high temperatures due to sintering and coarsening processes that are driven by their high surface to volume ratio. Therefore, new hydrogen and sulfur selective nanomaterial systems with high selectivity and stability properties in the proposed harsh environment were investigated. Different nano-morphologies of zirconate, molybdate, and tungstate compounds were investigated. The fabrication of the microsensors consisted of the deposition of the selective nanomaterial systems over metal based interconnects on an inert substrate. This work utilized the chemi-resistive (resistive- type) microsensor architecture where the chemically and structurally stable, high temperature compatible electrodes were sputtered onto a ceramic substrate. The nanomaterial sensing systems were deposited over the electrodes using a lost mold method patterned by conventional optical lithography. The microsensor configuration with optimized nanomaterial system was tested and compared to a millimeter-size sensor e outcomes of this research will contribute to the economical application of sensor arrays for simultaneous sensing of H 2, H 2S, and SO 2.« less

Intense Electrochemical Oxidation on Graphitized Carbon Electrodes in the Presence of Ozone

NASA Astrophysics Data System (ADS)

Klochikhin, V. L.; Potapova, G. F.; Putilov, A. V.

2018-06-01

A new intense oxidation process for water treatment in which oxidation with ozone is coupled to electrochemical processes is described, and the results from its application to water purification are presented along with the discussion of its practical implementation. The use of graphitized carbon materials for this process is explained and tested experimentally. The use of glassy carbon for the anode enables us to achieve very high (up to 25 vol %) concentrations of ozone in the generated ozone-oxygen mixture. The material used for the cathode—graphitized carbon cloth (GCC) reinforced with Ni allows different electrocatalytic processes to proceed on its developed surface, and combines the high sorption capacity of this cathode and potentialcontrolled selectivity of cathodic electrochemical processes.

Relationship between Small Animal Intern Rank and Performance at a University Teaching Hospital.

PubMed

Hofmeister, Erik H; Saba, Corey; Kent, Marc; Creevy, Kate E

2015-01-01

The purpose of this study was to determine if there is a relationship between selection committee rankings of internship applicants and the performance of small animal interns. The hypothesis was that there would be a relationship between selection committee rank order and intern performance; the more highly an application was ranked, the better the intern's performance scores would be. In 2007, the Department of Small Animal Medicine and Surgery instituted a standardized approach to its intern selection process both to streamline the process and to track its effectiveness. At the end of intern years 2010-2014, every faculty member in the department was provided an intern assessment form for that year's class. There was no relationship between an individual intern's final rank by the selection committee and his/her performance either as a percentile score or a Likert-type score (p=.25, R2=0.04; p=0.31, R2=0.03, respectively). Likewise, when interns were divided into the top and bottom quartile based on their final rank by the selection committee, there was no relationship between their rank and their performance as a percentile score (median rank 15 vs. 20; p=.14) or Likert-type score (median rank 14 vs. 19; p=.27). Institutions that use a similar intern selection method may need to reconsider the time and effort being expended for an outcome that does not predict performance. Alternatively, specific criteria more predictive of performance outcomes should be identified and employed in the internship selection process.

TiAlN/TiAlON/Si{sub 3}N{sub 4} tandem absorber for high temperature solar selective applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barshilia, Harish C.; Selvakumar, N.; Rajam, K. S.

2006-11-06

A tandem absorber of TiAlN/TiAlON/Si{sub 3}N{sub 4} is prepared using a magnetron sputtering process. The graded composition of the individual component layers of the tandem absorber produces a film with a refractive index increasing from the surface to the substrate, which exhibits a high absorptance (0.95) and a low emittance (0.07). The tandem absorber is stable in air up to 600 deg. C for 2 h, indicating its importance for high temperature solar selective applications. The thermal stability of the tandem absorber is attributed to high oxidation resistance and microstructural stability of the component materials at higher temperatures.

Defect, Microstructure, and Mechanical Property of Ti-6Al-4V Alloy Fabricated by High-Power Selective Laser Melting

NASA Astrophysics Data System (ADS)

Cao, Sheng; Chen, Zhuoer; Lim, Chao Voon Samuel; Yang, Kun; Jia, Qingbo; Jarvis, Tom; Tomus, Dacian; Wu, Xinhua

2017-12-01

To improve the selective laser melting (SLM) productivity, a high laser power and accordingly adjusted parameters are employed to facilitate a high build rate. Three distinct processing strategies with incremental build rate are developed for SLM Ti-6Al-4V. Various types of defects are investigated. Further studies were carried out by heat-treatment and hot isostatic pressing to evaluate the influence of microstructure and porosity on mechanical properties. The anisotropic mechanical property in horizontally and vertically build samples were observed, which was attributable to the columnar grains and spatial arrangement of defects. Regardless of anisotropy, a post-SLM heat-treatment at 800°C for 2 h produces a combined high strength and ductility.

Geoscientific Site Evaluation Approach for Canada's Deep Geological Repository for Used Nuclear Fuel

NASA Astrophysics Data System (ADS)

Sanchez-Rico Castejon, M.; Hirschorn, S.; Ben Belfadhel, M.

2015-12-01

The Nuclear Waste Management Organization (NWMO) is responsible for implementing Adaptive Phased Management, the approach selected by the Government of Canada for long-term management of used nuclear fuel generated by Canadian nuclear reactors. The ultimate objective of APM is the centralized containment and isolation of Canada's used nuclear fuel in a Deep Geological Repository in a suitable crystalline or sedimentary rock formation. In May 2010, the NWMO published and initiated a nine-step site selection process to find an informed and willing community to host a deep geological repository for Canada's used nuclear fuel. The site selection process is designed to address a broad range of technical and social, economic and cultural factors. The site evaluation process includes three main technical evaluation steps: Initial Screenings; Preliminary Assessments; and Detailed Site Characterizations, to assess the suitability of candidate areas in a stepwise manner over a period of many years. By the end of 2012, twenty two communities had expressed interest in learning more about the project. As of July 2015, nine communities remain in the site selection process. To date (July 2015), NWMO has completed Initial Screenings for the 22 communities that expressed interest, and has completed the first phase of Preliminary Assessments (desktop) for 20 of the communities. Phase 2 of the Preliminary Assessments has been initiated in a number of communities, with field activities such as high-resolution airborne geophysical surveys and geological mapping. This paper describes the approach, methods and criteria being used to assess the geoscientific suitability of communities currently involved in the site selection process.

DeNOx Abatement over Sonically Prepared Iron-Substituted Y, USY and MFI Zeolite Catalysts in Lean Exhaust Gas Conditions

PubMed Central

Stachurska, Patrycja; Kuterasiński, Łukasz; Dziedzicka, Anna; Górecka, Sylwia; Chmielarz, Lucjan; Łojewska, Joanna; Sitarz, Maciej

2018-01-01

Iron-substituted MFI, Y and USY zeolites prepared by two preparation routes—classical ion exchange and the ultrasound modified ion-exchange method—were characterised by micro-Raman spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), and ultraviolet (UV)/visible diffuse reflectance spectroscopy (UV/Vis DRS). Ultrasound irradiation, a new technique for the preparation of the metal salt suspension before incorporation to the zeolite structure, was employed. An experimental study of selective catalytic reduction (SCR) of NO with NH3 on both iron-substituted reference zeolite catalysts and those prepared through the application of ultrasound conducted during an ion-exchange process is presented. The prepared zeolite catalysts show high activity and selectivity in SCR deNOx abatement. The MFI-based iron catalysts, especially those prepared via the sonochemical method, revealed superior activity in the deNOx process, with almost 100% selectivity towards N2. The hydrothermal stability test confirmed high stability and activity of MFI-based catalysts in water-rich conditions during the deNOx reaction at 450 °C. PMID:29301370

Using "StorAge Selection" functions and high resolution isotope data to unravel travel time distributions in headwater catchments

NASA Astrophysics Data System (ADS)

Benettin, Paolo; Soulsby, Chris; Birkel, Christian; Tetzlaff, Doerthe; Botter, Gianluca; Rinaldo, Andrea

2017-04-01

We use high resolution tracer data from the Bruntland Burn catchment (UK) to test theoretical approaches that integrate catchment-scale flow and transport processes in a unified framework centered on selective age sampling by streamflow and evapotranspiration fluxes. Hydrologic transport is here described through StorAge Selection (SAS) functions, parametrized as simple power laws. By representing the way in which catchment storage generates outflows composed by water of different ages, the main mechanism regulating the tracer composition of runoff is clearly identified. The calibrated numerical model provides simulations that convincingly reproduce complex measured signals of daily deuterium content in stream waters during wet and dry periods. The results for the catchment under consideration are consistent with other recent studies indicating a tendency for natural catchments to preferentially release younger available water. The model allows estimating transient water age and its related uncertainty, as well as the total catchment storage. This study shows that power-law SAS functions prove a powerful tool to explain catchment-scale transport processes that also has potential in less intensively monitored sites.

Polymeric molecular sieve membranes via in situ cross-linking of non-porous polymer membrane templates.

PubMed

Qiao, Zhen-An; Chai, Song-Hai; Nelson, Kimberly; Bi, Zhonghe; Chen, Jihua; Mahurin, Shannon M; Zhu, Xiang; Dai, Sheng

2014-04-16

High-performance polymeric membranes for gas separation are attractive for molecular-level separations in industrial-scale chemical, energy and environmental processes. Molecular sieving materials are widely regarded as the next-generation membranes to simultaneously achieve high permeability and selectivity. However, most polymeric molecular sieve membranes are based on a few solution-processable polymers such as polymers of intrinsic microporosity. Here we report an in situ cross-linking strategy for the preparation of polymeric molecular sieve membranes with hierarchical and tailorable porosity. These membranes demonstrate exceptional performance as molecular sieves with high gas permeabilities and selectivities for smaller gas molecules, such as carbon dioxide and oxygen, over larger molecules such as nitrogen. Hence, these membranes have potential for large-scale gas separations of commercial and environmental relevance. Moreover, this strategy could provide a possible alternative to 'classical' methods for the preparation of porous membranes and, in some cases, the only viable synthetic route towards certain membranes.

In situ biodiesel production from greasy sewage sludge using acid and enzymatic catalysts.

PubMed

Sangaletti-Gerhard, Naiane; Cea, Mara; Risco, Vicky; Navia, Rodrigo

2015-03-01

This study proposes to select the most appropriate sewage sludge (greasy, primary and secondary) for in situ transesterification and to compare the technical, economic and energetic performance of an enzymatic catalyst (Novozym®435) with sulfuric acid. Greasy sludge was selected as feedstock for biodiesel production due to its high lipid content (44.4%) and low unsaponifiable matter. Maximum methyl esters yield (61%) was reached when processing the wet sludge using sulfuric acid as catalyst and n-hexane, followed by dried-greasy sludge catalyzed by Novozym®435 (57% methyl esters). Considering the economic point of view, the process using acid catalyst was more favorable compared to Novozym®435 catalyst due to the high cost of lipase. In general, greasy sludge (wet or dried) showed high potential to produce biodiesel. However, further technical adjustments are needed to make biodiesel production by in situ transesterification using acid and enzymatic catalyst feasible. Copyright © 2014 Elsevier Ltd. All rights reserved.

Endogenous attention modulates early selective attention in psychopathy: An ERP investigation.

PubMed

Krusemark, Elizabeth A; Kiehl, Kent A; Newman, Joseph P

2016-10-01

Psychopathic individuals are prone to act on urges without adequate consideration of future consequences or the rights of other individuals. One interpretation of this behavior is that it reflects abnormal selective attention (i.e., a failure to process information that is incongruent with their primary focus of attention; Hiatt, Schmitt, & Newman, Neuropsychology, 18, 50-59, 2004). Unfortunately, it is unclear whether this selective attention abnormality reflects top-down endogenous influences, such as the strength or specificity of attention focus (i.e., top-down set) apart from other, more exogenous (bottom-up), effects on attention. To explore this question, we used an early visual event-related potential (N2pc) in combination with a modified visual search task designed to assess the effect of early endogenous (i.e., top-down) attention on the processing of set-congruent information. The task was administered to a sample of 70 incarcerated adult males, who were assigned to high, intermediate, and low psychopathy groups using Hare's Psychopathy Checklist-Revised (Hare, 2003). Based on the assumption that their failure to process set-incongruent information reflects the exaggerated effects of endogenous attention, we predicted that participants with high psychopathy scores would show an exaggerated N2pc response to set-congruent information. The results supported the hypothesis and provide novel electrophysiological evidence that psychopathy is associated with exaggerated endogenous attention effects during early stages of processing. Further research is needed to examine the implications of this finding for the well-established failure of psychopathic individuals to process set-incongruent information and inhibit inappropriate responses.

Genetic variation of loci potentially under selection confounds species-genetic diversity correlations in a fragmented habitat.

PubMed

Bertin, Angeline; Gouin, Nicolas; Baumel, Alex; Gianoli, Ernesto; Serratosa, Juan; Osorio, Rodomiro; Manel, Stephanie

2017-01-01

Positive species-genetic diversity correlations (SGDCs) are often thought to result from the parallel influence of neutral processes on genetic and species diversity. Yet, confounding effects of non-neutral mechanisms have not been explored. Here, we investigate the impact of non-neutral genetic diversity on SGDCs in high Andean wetlands. We compare correlations between plant species diversity and genetic diversity (GD) calculated with and without loci potentially under selection (outlier loci). The study system includes 2188 specimens from five species (three common aquatic macroinvertebrate and two dominant plant species) that were genotyped for 396 amplified fragment length polymorphism loci. We also appraise the importance of neutral processes on SGDCs by investigating the influence of habitat fragmentation features. Significant positive SGDCs were detected for all five species (mean SGDC = 0.52 ± 0.05). While only a few outlier loci were detected in each species, they resulted in significant decreases in GD and in SGDCs. This supports the hypothesis that neutral processes drive species-genetic diversity relationships in high Andean wetlands. Unexpectedly, the effects on genetic diversity GD of the habitat fragmentation characteristics in this study increased with the presence of outlier loci in two species. Overall, our results reveal pitfalls in using habitat features to infer processes driving SGDCs and show that a few loci potentially under selection are enough to cause a significant downward bias in SGDC. Investigating confounding effects of outlier loci thus represents a useful approach to evidence the contribution of neutral processes on species-genetic diversity relationships. © 2016 John Wiley & Sons Ltd.

Continuous process for singlet oxygenation of hydrophobic substrates in microemulsion using a pervaporation membrane.

PubMed

Caron, Laurent; Nardello, Véronique; Mugge, José; Hoving, Erik; Alsters, Paul L; Aubry, Jean-Marie

2005-02-15

Chemically generated singlet oxygen (1O2, 1Deltag) is able to oxidize a great deal of hydrophobic substrates from molybdate-catalyzed hydrogen peroxide decomposition, provided a suitable reaction medium such as a microemulsion system is used. However, high substrate concentrations or poorly reactive organics require large amounts of H2O2 that generate high amounts of water and thus destabilize the system. We report results obtained on combining dark singlet oxygenation of hydrophobic substrates in microemulsions with a pervaporation membrane process. To avoid composition alterations after addition of H2O2 during the peroxidation, the reaction mixture circulates through a ceramic membrane module that enables a partial and selective dewatering of the microemulsion. Optimization phase diagrams of sodium molybdate/water/alcohol/anionic surfactant/organic solvent have been elaborated to maximize the catalyst concentration and therefore the reaction rate. The membrane selectivity towards the mixture constituents has been investigated showing that a high retention is observed for the catalyst, for organic solvents and hydrophobic substrates, but not for n-propanol (cosurfactant) and water. The efficiency of such a process is illustrated with the peroxidation of a poorly reactive substrate, viz., beta-pinene.

Affective ERP Processing in a Visual Oddball Task: Arousal, Valence, and Gender

PubMed Central

Rozenkrants, Bella; Polich, John

2008-01-01

Objective To assess affective event-related brain potentials (ERPs) using visual pictures that were highly distinct on arousal level/valence category ratings and a response task. Methods Images from the International Affective Pictures System (IAPS) were selected to obtain distinct affective arousal (low, high) and valence (negative, positive) rating levels. The pictures were used as target stimuli in an oddball paradigm, with a visual pattern as the standard stimulus. Participants were instructed to press a button whenever a picture occurred and to ignore the standard. Task performance and response time did not differ across conditions. Results High-arousal compared to low-arousal stimuli produced larger amplitudes for the N2, P3, early slow wave, and late slow wave components. Valence amplitude effects were weak overall and originated primarily from the later waveform components and interactions with electrode position. Gender differences were negligible. Conclusion The findings suggest that arousal level is the primary determinant of affective oddball processing, and valence minimally influences ERP amplitude. Significance Affective processing engages selective attentional mechanisms that are primarily sensitive to the arousal properties of emotional stimuli. The application and nature of task demands are important considerations for interpreting these effects. PMID:18783987

Hybrid and Mixed Matrix Membranes for Separations from Fermentations

PubMed Central

Davey, Christopher John; Leak, David; Patterson, Darrell Alec

2016-01-01

Fermentations provide an alternative to fossil fuels for accessing a number of biofuel and chemical products from a variety of renewable and waste substrates. The recovery of these dilute fermentation products from the broth, however, can be incredibly energy intensive as a distillation process is generally involved and creates a barrier to commercialization. Membrane processes can provide a low energy aid/alternative for recovering these dilute fermentation products and reduce production costs. For these types of separations many current polymeric and inorganic membranes suffer from poor selectivity and high cost respectively. This paper reviews work in the production of novel mixed-matrix membranes (MMMs) for fermentative separations and those applicable to these separations. These membranes combine a trade-off of low-cost and processability of polymer membranes with the high selectivity of inorganic membranes. Work within the fields of nanofiltration, reverse osmosis and pervaporation has been discussed. The review shows that MMMs are currently providing some of the most high-performing membranes for these separations, with three areas for improvement identified: Further characterization and optimization of inorganic phase(s), Greater understanding of the compatibility between the polymer and inorganic phase(s), Improved methods for homogeneously dispersing the inorganic phase. PMID:26938567

Friction Stir Welding of Steel Alloys

NASA Technical Reports Server (NTRS)

Ding, R. Jeffrey; Munafo, Paul M. (Technical Monitor)

2001-01-01

The friction stir welding process has been developed primarily for the welding of aluminum alloys. Other higher melting allows such, as steels are much more difficult to join. Special attention must be given to pin tool material selection and welding techniques. This paper addresses the joining of steels and other high melting point materials using the friction stir welding process. Pin tool material and welding parameters will be presented. Mechanical properties of weldments will also be presented. Significance: There are many applications for the friction stir welding process other than low melting aluminum alloys. The FSW process can be expanded for use with high melting alloys in the pressure vessel, railroad and ship building industries.

Dry etched SiO2 Mask for HgCdTe Etching Process

NASA Astrophysics Data System (ADS)

Chen, Y. Y.; Ye, Z. H.; Sun, C. H.; Deng, L. G.; Zhang, S.; Xing, W.; Hu, X. N.; Ding, R. J.; He, L.

2016-09-01

A highly anisotropic etching process with low etch-induced damage is indispensable for advanced HgCdTe (MCT) infrared focal plane array (IRFPA) detectors. The inductively coupled plasma (ICP) enhanced reactive ion etching technique has been widely adopted in manufacturing HgCdTe IRFPA devices. An accurately patterned mask with sharp edges is decisive to accomplish pattern duplication. It has been reported by our group that the SiO2 mask functions well in etching HgCdTe with high selectivity. However, the wet process in defining the SiO2 mask is limited by ambiguous edges and nonuniform patterns. In this report, we patterned SiO2 with a mature ICP etching technique, prior to which a thin ZnS film was deposited by thermal evaporation. The SiO2 film etching can be terminated at the auto-stopping point of the ZnS layer thanks to the high selectivity of SiO2/ZnS in SF6 based etchant. Consequently, MCT etching was directly performed without any other treatment. This mask showed acceptable profile due to the maturity of the SiO2 etching process. The well-defined SiO2 pattern and the etched smooth surfaces were investigated with scanning electron microscopy and atomic force microscope. This new mask process could transfer the patterns exactly with very small etch-bias. A cavity with aspect-ratio (AR) of 1.2 and root mean square roughness of 1.77 nm was achieved first, slightly higher AR of 1.67 was also get with better mask profile. This masking process ensures good uniformity and surely benefits the delineation of shrinking pixels with its high resolution.

Improving the efficiency of CHO cell line generation using glutamine synthetase gene knockout cells.

PubMed

Fan, Lianchun; Kadura, Ibrahim; Krebs, Lara E; Hatfield, Christopher C; Shaw, Margaret M; Frye, Christopher C

2012-04-01

Although Chinese hamster ovary (CHO) cells, with their unique characteristics, have become a major workhorse for the manufacture of therapeutic recombinant proteins, one of the major challenges in CHO cell line generation (CLG) is how to efficiently identify those rare, high-producing clones among a large population of low- and non-productive clones. It is not unusual that several hundred individual clones need to be screened for the identification of a commercial clonal cell line with acceptable productivity and growth profile making the cell line appropriate for commercial application. This inefficiency makes the process of CLG both time consuming and laborious. Currently, there are two main CHO expression systems, dihydrofolate reductase (DHFR)-based methotrexate (MTX) selection and glutamine synthetase (GS)-based methionine sulfoximine (MSX) selection, that have been in wide industrial use. Since selection of recombinant cell lines in the GS-CHO system is based on the balance between the expression of the GS gene introduced by the expression plasmid and the addition of the GS inhibitor, L-MSX, the expression of GS from the endogenous GS gene in parental CHOK1SV cells will likely interfere with the selection process. To study endogenous GS expression's potential impact on selection efficiency, GS-knockout CHOK1SV cell lines were generated using the zinc finger nuclease (ZFN) technology designed to specifically target the endogenous CHO GS gene. The high efficiency (∼2%) of bi-allelic modification on the CHO GS gene supports the unique advantages of the ZFN technology, especially in CHO cells. GS enzyme function disruption was confirmed by the observation of glutamine-dependent growth of all GS-knockout cell lines. Full evaluation of the GS-knockout cell lines in a standard industrial cell culture process was performed. Bulk culture productivity improved two- to three-fold through the use of GS-knockout cells as parent cells. The selection stringency was significantly increased, as indicated by the large reduction of non-producing and low-producing cells after 25 µM L-MSX selection, and resulted in a six-fold efficiency improvement in identifying similar numbers of high-productive cell lines for a given recombinant monoclonal antibody. The potential impact of GS-knockout cells on recombinant protein quality is also discussed. Copyright © 2011 Wiley Periodicals, Inc.

Are "High Potential" Executives Capable of Building Learning-Oriented Organisations? Reflections on the French Case

ERIC Educational Resources Information Center

Belet, Daniel

2007-01-01

Purpose: The author's interest in learning organisation development leads him to examine large French companies' practices regarding "high potential" executives policies and to question their selection and development processes and their capabilities to develop learning oriented organisations.The author also tries to explain why most…

High School Girls' Perceptions of Selected Fitness Activities

ERIC Educational Resources Information Center

Wilkinson, Carol; Bretzing, Robyn

2011-01-01

High school students, and particularly girls, are not very active (Centers for Disease Control and Prevention, 2006). To help girls develop the abilities to enjoy lifetime, healthy physical activity, physical educators need to provide curricula that will achieve this goal. In the process, they need to make sure they are aligned with the current…

Evaluation of Mars CO2 Capture and Gas Separation Technologies

NASA Technical Reports Server (NTRS)

Muscatello, Anthony C.; Santiago-Maldonado, Edgardo; Gibson, Tracy; Devor, Robert; Captain, James

2011-01-01

Recent national policy statements have established that the ultimate destination of NASA's human exploration program is Mars. In Situ Resource Utilization (ISRU) is a key technology required to ,enable such missions and it is appropriate to review progress in this area and continue to advance the systems required to produce rocket propellant, oxygen, and other consumables on Mars using the carbon dioxide atmosphere and other potential resources. The Mars Atmospheric Capture and Gas separation project is selecting, developing, and demonstrating techniques to capture and purify Martian atmospheric gases for their utilization for the production of hydrocarbons, oxygen, and water in ISRU systems. Trace gases will be required to be separated from Martian atmospheric gases to provide pure CO2 to processing elements. In addition, other Martian gases, such as nitrogen and argon, occur in concentrations high enough to be useful as buffer gas and should be captured as well. To achieve these goals, highly efficient gas separation processes will be required. These gas separation techniques are also required across various areas within the ISRU project to support various consumable production processes. The development of innovative gas separation techniques will evaluate the current state-of-the-art for the gas separation required, with the objective to demonstrate and develop light-weight, low-power methods for gas separation. Gas separation requirements include, but are not limited to the selective separation of: (1) methane and water from unreacted carbon oxides (C02-CO) and hydrogen typical of a Sabatier-type process, (2) carbon oxides and water from unreacted hydrogen from a Reverse Water-Gas Shift process, (3)/carbon oxides from oxygen from a trash/waste processing reaction, and (4) helium from hydrogen or oxygen from a propellant scavenging process. Potential technologies for the separations include' freezers, selective membranes, selective solvents, polymeric sorbents, zeolites, and new technologies. This paper summarizes the results of an extensive literature review of candidate technologies for the capture and separation of CO2 and other relevant gases. This information will be used to prioritize the technologies to be developed further during this and other ISRU projects.

Chemo-selective high yield microwave assisted reaction turns cellulose to green chemicals.

PubMed

Hassanzadeh, Salman; Aminlashgari, Nina; Hakkarainen, Minna

2014-11-04

Exceptionally high cellulose liquefaction yields, up to 87% as calculated from the amount of solid residue, were obtained under mild conditions by utilizing the synergistic effect of microwave radiation and acid catalysis. The effect of processing conditions on degradation products was fingerprinted by rapid laser desorption ionization-mass spectrometry (LDI-MS) method. The reaction was chemo-tunable, enabling production of glucose (Glc) or levulinic acid (LeA) at significantly high selectivity and yields, the relative molar yields being up to 50 and 69%, respectively. A turning point from pure depolymerization to glucose to further degradation to levulinic acid and formic acid was observed at approximately 50% liquefaction or above 140 °C. This was accompanied by the formation of small amounts of solid spherical carbonized residues. The reaction was monitored by multiple analytical techniques. The high yields were connected to the ability of the process to break the strong secondary interactions in cellulose. The developed method has great potential for future production of green platform chemicals. Copyright © 2014 Elsevier Ltd. All rights reserved.

A scalable, fully automated process for construction of sequence-ready human exome targeted capture libraries

PubMed Central

2011-01-01

Genome targeting methods enable cost-effective capture of specific subsets of the genome for sequencing. We present here an automated, highly scalable method for carrying out the Solution Hybrid Selection capture approach that provides a dramatic increase in scale and throughput of sequence-ready libraries produced. Significant process improvements and a series of in-process quality control checkpoints are also added. These process improvements can also be used in a manual version of the protocol. PMID:21205303

Laser-induced selective copper plating of polypropylene surface

NASA Astrophysics Data System (ADS)

Ratautas, K.; Gedvilas, M.; Stankevičiene, I.; JagminienÄ--, A.; Norkus, E.; Li Pira, N.; Sinopoli, S.; Emanuele, U.; Račiukaitis, G.

2016-03-01

Laser writing for selective plating of electro-conductive lines for electronics has several significant advantages, compared to conventional printed circuit board technology. Firstly, this method is faster and cheaper at the prototyping stage. Secondly, material consumption is reduced, because it works selectively. However, the biggest merit of this method is potentiality to produce moulded interconnect device, enabling to create electronics on complex 3D surfaces, thus saving space, materials and cost of production. There are two basic techniques of laser writing for selective plating on plastics: the laser-induced selective activation (LISA) and laser direct structuring (LDS). In the LISA method, pure plastics without any dopant (filler) can be used. In the LDS method, special fillers are mixed in the polymer matrix. These fillers are activated during laser writing process, and, in the next processing step, the laser modified area can be selectively plated with metals. In this work, both methods of the laser writing for the selective plating of polymers were investigated and compared. For LDS approach, new material: polypropylene with carbon-based additives was tested using picosecond and nanosecond laser pulses. Different laser processing parameters (laser pulse energy, scanning speed, the number of scans, pulse durations, wavelength and overlapping of scanned lines) were applied in order to find out the optimal regime of activation. Areal selectivity tests showed a high plating resolution. The narrowest width of a copper-plated line was less than 23 μm. Finally, our material was applied to the prototype of the electronic circuit board on a 2D surface.

Manufacturing Process Selection of Composite Bicycle’s Crank Arm using Analytical Hierarchy Process (AHP)

NASA Astrophysics Data System (ADS)

Luqman, M.; Rosli, M. U.; Khor, C. Y.; Zambree, Shayfull; Jahidi, H.

2018-03-01

Crank arm is one of the important parts in a bicycle that is an expensive product due to the high cost of material and production process. This research is aimed to investigate the potential type of manufacturing process to fabricate composite bicycle crank arm and to describe an approach based on analytical hierarchy process (AHP) that assists decision makers or manufacturing engineers in determining the most suitable process to be employed in manufacturing of composite bicycle crank arm at the early stage of the product development process to reduce the production cost. There are four types of processes were considered, namely resin transfer molding (RTM), compression molding (CM), vacuum bag molding and filament winding (FW). The analysis ranks these four types of process for its suitability in the manufacturing of bicycle crank arm based on five main selection factors and 10 sub factors. Determining the right manufacturing process was performed based on AHP process steps. Consistency test was performed to make sure the judgements are consistent during the comparison. The results indicated that the compression molding was the most appropriate manufacturing process because it has the highest value (33.6%) among the other manufacturing processes.

Presidential Green Chemistry Challenge: 1998 Designing Greener Chemicals Award

EPA Pesticide Factsheets

Presidential Green Chemistry Challenge 1998 award winner, Rohm and Haas, developed CONFIRM, a highly selective, reduced risk insecticide that disrupts the molting process of caterpillar pests in turf and a variety of crops.

Coal conversion systems design and process modeling. Volume 1: Application of MPPR and Aspen computer models

NASA Technical Reports Server (NTRS)

1981-01-01

The development of a coal gasification system design and mass and energy balance simulation program for the TVA and other similar facilities is described. The materials-process-product model (MPPM) and the advanced system for process engineering (ASPEN) computer program were selected from available steady state and dynamic models. The MPPM was selected to serve as the basis for development of system level design model structure because it provided the capability for process block material and energy balance and high-level systems sizing and costing. The ASPEN simulation serves as the basis for assessing detailed component models for the system design modeling program. The ASPEN components were analyzed to identify particular process blocks and data packages (physical properties) which could be extracted and used in the system design modeling program. While ASPEN physical properties calculation routines are capable of generating physical properties required for process simulation, not all required physical property data are available, and must be user-entered.

Pyrolysis of polystyrene - polyphenylene oxide to recover styrene and useful products

DOEpatents

Evans, Robert J.; Chum, Helena L.

1995-01-01

A process of using fast pyrolysis in a carrier gas to convert a polystyrene and polyphenylene oxide plastic waste to a given polystyrene and polyphenylene oxide prior to pyrolysis of other plastic components therein comprising: selecting a first temperature range to cause pyrolysis of given polystyrene and polyphenylene oxide and its high value monomeric constituent prior to a temperature range that causes pyrolysis of other plastic components; selecting a catalyst and a support and treating the feed stream with the catalyst to affect acid or base catalyzed reaction pathways to maximize yield or enhance separation of high value monomeric constituent of styrene from polystyrene and polyphenylene oxide in the first temperature range; differentially heating the feed stream at a heat rate within the first temperature range to provide differential pyrolysis for selective recovery of the high value monomeric constituent of styrene from polystyrene and polyphenylene oxide prior to pyrolysis of other plastic components; separating the high value monomer constituent of styrene; selecting a second higher temperature range to cause pyrolysis to a different derived high value product of polyphenylene oxide from the plastic waste and differentially heating the feed stream at the higher temperature range to cause pyrolysis of the plastic into a polyphenylene oxide derived product; and separating the different derived high value polyphenylene oxide product.

Altered selection during language processing in individuals at high risk for psychosis.

PubMed

Vargas, T; Snyder, H; Banich, M; Newberry, R; Shankman, Stewart A; Strauss, Gregory P; Mittal, V A

2018-06-19

Performance in the executive function (EF) domain has been linked to symptoms and functional outcomes in psychosis. Studies have found that UHR populations have difficulty with verbal fluency, which involves multiple facets of EF. Two potentially implicated EF facets were examined to explore whether these could be dissociated in UHR populations: selection among alternatives (measured by selection costs) and retrieval from semantic memory retrieval (measured by retrieval costs). A total of 45 UHR individuals and 46 healthy controls (HVs) were assessed with a verb generation task. Differences in selection cost (RT difference between high and low selection demand conditions) and retrieval cost (RT difference between high and low retrieval demand conditions) were examined and participants were also assessed for clinical symptoms. The UHR group showed greater selection costs relative to HVs, F (1, 91) = 4.39, p = 0.039. However, there were no group differences on retrieval cost, F (1, 91) = 0.63, p = 0.43. A positive association (r = 0.41) was found between disorganized and negative symptoms and selection costs (but not retrieval costs) in the UHR group. There was no significant association between selection costs and positive symptoms. Increased selection costs may reflect impaired performance in the neural inhibition domain of EF in the UHR population, potentially underlying a mechanistically distinct EF subdomain that affects the group's ability to efficiently select between competing options. Findings suggest that UHR individuals may exhibit impairment in selecting among alternatives, but not in retrieval from semantic memory. Copyright © 2018 Elsevier B.V. All rights reserved.

Derivation of an artificial gene to improve classification accuracy upon gene selection.

PubMed

Seo, Minseok; Oh, Sejong

2012-02-01

Classification analysis has been developed continuously since 1936. This research field has advanced as a result of development of classifiers such as KNN, ANN, and SVM, as well as through data preprocessing areas. Feature (gene) selection is required for very high dimensional data such as microarray before classification work. The goal of feature selection is to choose a subset of informative features that reduces processing time and provides higher classification accuracy. In this study, we devised a method of artificial gene making (AGM) for microarray data to improve classification accuracy. Our artificial gene was derived from a whole microarray dataset, and combined with a result of gene selection for classification analysis. We experimentally confirmed a clear improvement of classification accuracy after inserting artificial gene. Our artificial gene worked well for popular feature (gene) selection algorithms and classifiers. The proposed approach can be applied to any type of high dimensional dataset. Copyright © 2011 Elsevier Ltd. All rights reserved.

Porous and magnetic molecularly imprinted polymers via Pickering high internal phase emulsions polymerization for selective adsorption of λ-cyhalothrin

NASA Astrophysics Data System (ADS)

Wu, Yunlong; Ma, Yue; Pan, Jianming; Gu, Runxing; Luo, Jialu

2017-03-01

A novel macroporous magnetic molecularly imprinted polymer (MMIPs) of was prepared by W/O Pickering (high internal phase emulsions) HIPEs polymerization, and then it was adopted as adsorbent for selective adsorption of λ-cyhalothrin (LC). In static conditions, adsorption capacity of LC increased rapidly in the first 60 min and reached to equilibrium in approximately 2.0 h. Excellent conformity of the second-order model confirmed the chemical nature of the interaction between the LC and imprinted sites. The fitting adsorption isotherm was a Langmuir type, and the maximum monolayer adsorption capacity at 298 K was 404.4 µmol g-1. Thermodynamic parameters suggested the specific adsorption at 298 K was an exothermic, spontaneous, and entropy decreased process. Competitive recognition studies of the MMIPs were performed with diethyl phthalate (DEP) and the structurally similar compound fenvalerate (FL), and the MMIPs, which displayed high selectivity for LC.

Highly selective covalent organic functionalization of epitaxial graphene

NASA Astrophysics Data System (ADS)

Bueno, Rebeca A.; Martínez, José I.; Luccas, Roberto F.; Del Árbol, Nerea Ruiz; Munuera, Carmen; Palacio, Irene; Palomares, Francisco J.; Lauwaet, Koen; Thakur, Sangeeta; Baranowski, Jacek M.; Strupinski, Wlodek; López, María F.; Mompean, Federico; García-Hernández, Mar; Martín-Gago, José A.

2017-05-01

Graphene functionalization with organics is expected to be an important step for the development of graphene-based materials with tailored electronic properties. However, its high chemical inertness makes difficult a controlled and selective covalent functionalization, and most of the works performed up to the date report electrostatic molecular adsorption or unruly functionalization. We show hereafter a mechanism for promoting highly specific covalent bonding of any amino-terminated molecule and a description of the operating processes. We show, by different experimental techniques and theoretical methods, that the excess of charge at carbon dangling-bonds formed on single-atomic vacancies at the graphene surface induces enhanced reactivity towards a selective oxidation of the amino group and subsequent integration of the nitrogen within the graphene network. Remarkably, functionalized surfaces retain the electronic properties of pristine graphene. This study opens the door for development of graphene-based interfaces, as nano-bio-hybrid composites, fabrication of dielectrics, plasmonics or spintronics.

Porous and Magnetic Molecularly Imprinted Polymers via Pickering High Internal Phase Emulsions Polymerization for Selective Adsorption of λ-Cyhalothrin.

PubMed

Wu, Yunlong; Ma, Yue; Pan, Jianming; Gu, Runxing; Luo, Jialu

2017-01-01

A novel macroporous magnetic molecularly imprinted polymer (MMIPs) of was prepared by W/O Pickering (high internal phase emulsions) HIPEs polymerization, and then it was adopted as adsorbent for selective adsorption of λ-cyhalothrin (LC). In static conditions, adsorption capacity of LC increased rapidly in the first 60 min and reached to equilibrium in ~2.0 h. Excellent conformity of the second-order model confirmed the chemical nature of the interaction between the LC and imprinted sites. The fitting adsorption isotherm was a Langmuir type, and the maximum monolayer adsorption capacity at 298 K was 404.4 μmol g -1 . Thermodynamic parameters suggested the specific adsorption at 298 K was an exothermic, spontaneous, and entropy decreased process. Competitive recognition studies of the MMIPs were performed with diethyl phthalate (DEP) and the structurally similar compound fenvalerate (FL), and the MMIPs, which displayed high selectivity for LC.

Porous and Magnetic Molecularly Imprinted Polymers via Pickering High Internal Phase Emulsions Polymerization for Selective Adsorption of λ-Cyhalothrin

PubMed Central

Wu, Yunlong; Ma, Yue; Pan, Jianming; Gu, Runxing; Luo, Jialu

2017-01-01

A novel macroporous magnetic molecularly imprinted polymer (MMIPs) of was prepared by W/O Pickering (high internal phase emulsions) HIPEs polymerization, and then it was adopted as adsorbent for selective adsorption of λ-cyhalothrin (LC). In static conditions, adsorption capacity of LC increased rapidly in the first 60 min and reached to equilibrium in ~2.0 h. Excellent conformity of the second-order model confirmed the chemical nature of the interaction between the LC and imprinted sites. The fitting adsorption isotherm was a Langmuir type, and the maximum monolayer adsorption capacity at 298 K was 404.4 μmol g−1. Thermodynamic parameters suggested the specific adsorption at 298 K was an exothermic, spontaneous, and entropy decreased process. Competitive recognition studies of the MMIPs were performed with diethyl phthalate (DEP) and the structurally similar compound fenvalerate (FL), and the MMIPs, which displayed high selectivity for LC. PMID:28401145

Protein and Antibody Engineering by Phage Display

PubMed Central

Frei, J.C.; Lai, J.R.

2017-01-01

Phage display is an in vitro selection technique that allows for the rapid isolation of proteins with desired properties including increased affinity, specificity, stability, and new enzymatic activity. The power of phage display relies on the phenotype-to-genotype linkage of the protein of interest displayed on the phage surface with the encoding DNA packaged within the phage particle, which allows for selective enrichment of library pools and high-throughput screening of resulting clones. As an in vitro method, the conditions of the binding selection can be tightly controlled. Due to the high-throughput nature, rapidity, and ease of use, phage display is an excellent technological platform for engineering antibody or proteins with enhanced properties. Here, we describe methods for synthesis, selection, and screening of phage libraries with particular emphasis on designing humanizing antibody libraries and combinatorial scanning mutagenesis libraries. We conclude with a brief section on troubleshooting for all stages of the phage display process. PMID:27586328

Mediators of Effects of a Selective Family-Focused Violence Prevention Approach for Middle School Students

PubMed Central

2013-01-01

This study examined how parenting and family characteristics targeted in a selective prevention program mediated effects on key youth proximal outcomes related to violence perpetration. The selective intervention was evaluated within the context of a multi-site trial involving random assignment of 37 schools to four conditions: a universal intervention composed of a student social-cognitive curriculum and teacher training, a selective family-focused intervention with a subset of high-risk students, a condition combining these two interventions, and a no-intervention control condition. Two cohorts of sixth-grade students (total N=1,062) exhibiting high levels of aggression and social influence were the sample for this study. Analyses of pre-post change compared to controls using intent-to-treat analyses found no significant effects. However, estimates incorporating participation of those assigned to the intervention and predicted participation among those not assigned revealed significant positive effects on student aggression, use of aggressive strategies for conflict management, and parental estimation of student’s valuing of achievement. Findings also indicated intervention effects on two targeted family processes: discipline practices and family cohesion. Mediation analyses found evidence that change in these processes mediated effects on some outcomes, notably aggressive behavior and valuing of school achievement. Results support the notion that changing parenting practices and the quality of family relationships can prevent the escalation in aggression and maintain positive school engagement for high-risk youth. PMID:21932067

Population genomics of the killer whale indicates ecotype evolution in sympatry involving both selection and drift.

PubMed

Moura, Andre E; Kenny, John G; Chaudhuri, Roy; Hughes, Margaret A; J Welch, Andreanna; Reisinger, Ryan R; de Bruyn, P J Nico; Dahlheim, Marilyn E; Hall, Neil; Hoelzel, A Rus

2014-11-01

The evolution of diversity in the marine ecosystem is poorly understood, given the relatively high potential for connectivity, especially for highly mobile species such as whales and dolphins. The killer whale (Orcinus orca) has a worldwide distribution, and individual social groups travel over a wide geographic range. Even so, regional populations have been shown to be genetically differentiated, including among different foraging specialists (ecotypes) in sympatry. Given the strong matrifocal social structure of this species together with strong resource specializations, understanding the process of differentiation will require an understanding of the relative importance of both genetic drift and local adaptation. Here we provide a high-resolution analysis based on nuclear single-nucleotide polymorphic markers and inference about differentiation at both neutral loci and those potentially under selection. We find that all population comparisons, within or among foraging ecotypes, show significant differentiation, including populations in parapatry and sympatry. Loci putatively under selection show a different pattern of structure compared to neutral loci and are associated with gene ontology terms reflecting physiologically relevant functions (e.g. related to digestion). The pattern of differentiation for one ecotype in the North Pacific suggests local adaptation and shows some fixed differences among sympatric ecotypes. We suggest that differential habitat use and resource specializations have promoted sufficient isolation to allow differential evolution at neutral and functional loci, but that the process is recent and dependent on both selection and drift. © 2014 The Authors. Molecular Ecology published by John Wiley & Sons Ltd.

Population genomics of the killer whale indicates ecotype evolution in sympatry involving both selection and drift

PubMed Central

Moura, Andre E; Kenny, John G; Chaudhuri, Roy; Hughes, Margaret A; J Welch, Andreanna; Reisinger, Ryan R; de Bruyn, P J Nico; Dahlheim, Marilyn E; Hall, Neil; Hoelzel, A Rus

2014-01-01

The evolution of diversity in the marine ecosystem is poorly understood, given the relatively high potential for connectivity, especially for highly mobile species such as whales and dolphins. The killer whale (Orcinus orca) has a worldwide distribution, and individual social groups travel over a wide geographic range. Even so, regional populations have been shown to be genetically differentiated, including among different foraging specialists (ecotypes) in sympatry. Given the strong matrifocal social structure of this species together with strong resource specializations, understanding the process of differentiation will require an understanding of the relative importance of both genetic drift and local adaptation. Here we provide a high-resolution analysis based on nuclear single-nucleotide polymorphic markers and inference about differentiation at both neutral loci and those potentially under selection. We find that all population comparisons, within or among foraging ecotypes, show significant differentiation, including populations in parapatry and sympatry. Loci putatively under selection show a different pattern of structure compared to neutral loci and are associated with gene ontology terms reflecting physiologically relevant functions (e.g. related to digestion). The pattern of differentiation for one ecotype in the North Pacific suggests local adaptation and shows some fixed differences among sympatric ecotypes. We suggest that differential habitat use and resource specializations have promoted sufficient isolation to allow differential evolution at neutral and functional loci, but that the process is recent and dependent on both selection and drift. PMID:25244680

Propulsion for the lunar mission

NASA Technical Reports Server (NTRS)

Jones, Lee W.; Champion, Robert H., Jr.

1990-01-01

The paper describes the selection process utilized by NASA during the conduct of the 90-day study of the mission set that is known as the Space Exploration Initiative (SEI). It is directed specifically toward propulsion system definition and selection, with emphasis on the proposed Lunar Transfer Vehicle and the Lunar Exploration Vehicle. Results of trade studies show that selection cannot be readily made on the basis of engine performance alone, because the cost of launching hardware elements and the required propellant are very high. A decision must be made to use either life-cycle costs or annual program costs as the economic figure of merit, because they drive the selection in opposite directions.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Chen; Metzler, Dominik; Oehrlein, Gottlieb S., E-mail: oehrlein@umd.edu

Angstrom-level plasma etching precision is required for semiconductor manufacturing of sub-10 nm critical dimension features. Atomic layer etching (ALE), achieved by a series of self-limited cycles, can precisely control etching depths by limiting the amount of chemical reactant available at the surface. Recently, SiO{sub 2} ALE has been achieved by deposition of a thin (several Angstroms) reactive fluorocarbon (FC) layer on the material surface using controlled FC precursor flow and subsequent low energy Ar{sup +} ion bombardment in a cyclic fashion. Low energy ion bombardment is used to remove the FC layer along with a limited amount of SiO{sub 2} frommore » the surface. In the present article, the authors describe controlled etching of Si{sub 3}N{sub 4} and SiO{sub 2} layers of one to several Angstroms using this cyclic ALE approach. Si{sub 3}N{sub 4} etching and etching selectivity of SiO{sub 2} over Si{sub 3}N{sub 4} were studied and evaluated with regard to the dependence on maximum ion energy, etching step length (ESL), FC surface coverage, and precursor selection. Surface chemistries of Si{sub 3}N{sub 4} were investigated by x-ray photoelectron spectroscopy (XPS) after vacuum transfer at each stage of the ALE process. Since Si{sub 3}N{sub 4} has a lower physical sputtering energy threshold than SiO{sub 2}, Si{sub 3}N{sub 4} physical sputtering can take place after removal of chemical etchant at the end of each cycle for relatively high ion energies. Si{sub 3}N{sub 4} to SiO{sub 2} ALE etching selectivity was observed for these FC depleted conditions. By optimization of the ALE process parameters, e.g., low ion energies, short ESLs, and/or high FC film deposition per cycle, highly selective SiO{sub 2} to Si{sub 3}N{sub 4} etching can be achieved for FC accumulation conditions, where FC can be selectively accumulated on Si{sub 3}N{sub 4} surfaces. This highly selective etching is explained by a lower carbon consumption of Si{sub 3}N{sub 4} as compared to SiO{sub 2}. The comparison of C{sub 4}F{sub 8} and CHF{sub 3} only showed a difference in etching selectivity for FC depleted conditions. For FC accumulation conditions, precursor chemistry has a weak impact on etching selectivity. Surface chemistry analysis shows that surface fluorination and FC reduction take place during a single ALE cycle for FC depleted conditions. A fluorine rich carbon layer was observed on the Si{sub 3}N{sub 4} surface after ALE processes for which FC accumulation takes place. The angle resolved-XPS thickness calculations confirmed the results of the ellipsometry measurements in all cases.« less

C. botulinum inactivation kinetics implemented in a computational model of a high-pressure sterilization process.

PubMed

Juliano, Pablo; Knoerzer, Kai; Fryer, Peter J; Versteeg, Cornelis

2009-01-01

High-pressure, high-temperature (HPHT) processing is effective for microbial spore inactivation using mild preheating, followed by rapid volumetric compression heating and cooling on pressure release, enabling much shorter processing times than conventional thermal processing for many food products. A computational thermal fluid dynamic (CTFD) model has been developed to model all processing steps, including the vertical pressure vessel, an internal polymeric carrier, and food packages in an axis-symmetric geometry. Heat transfer and fluid dynamic equations were coupled to four selected kinetic models for the inactivation of C. botulinum; the traditional first-order kinetic model, the Weibull model, an nth-order model, and a combined discrete log-linear nth-order model. The models were solved to compare the resulting microbial inactivation distributions. The initial temperature of the system was set to 90 degrees C and pressure was selected at 600 MPa, holding for 220 s, with a target temperature of 121 degrees C. A representation of the extent of microbial inactivation throughout all processing steps was obtained for each microbial model. Comparison of the models showed that the conventional thermal processing kinetics (not accounting for pressure) required shorter holding times to achieve a 12D reduction of C. botulinum spores than the other models. The temperature distribution inside the vessel resulted in a more uniform inactivation distribution when using a Weibull or an nth-order kinetics model than when using log-linear kinetics. The CTFD platform could illustrate the inactivation extent and uniformity provided by the microbial models. The platform is expected to be useful to evaluate models fitted into new C. botulinum inactivation data at varying conditions of pressure and temperature, as an aid for regulatory filing of the technology as well as in process and equipment design.

Environmental Biotechnology: Moving from the Flask to the Field

DTIC Science & Technology

1991-09-30

biosorption , Biosorption of metal ions is a phenome- non exhibited by both alive and dead microbial cells. The detailed investigation of the mechanism of... biosorption has revealed that biosorption is a physical-chemical process whereby selected areas of the microbial cell exhibit high selectivity and...dead cells than by the same cells alive. The use of proper chemical solutions (eluants) is capable of reversing the equilibrium of biosorption

A Selectivity based approach to Continuous Pattern Detection in Streaming Graphs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Choudhury, Sutanay; Holder, Larry; Chin, George

2015-05-27

Cyber security is one of the most significant technical challenges in current times. Detecting adversarial activities, prevention of theft of intellectual properties and customer data is a high priority for corporations and government agencies around the world. Cyber defenders need to analyze massive-scale, high-resolution network flows to identify, categorize, and mitigate attacks involving networks spanning institutional and national boundaries. Many of the cyber attacks can be described as subgraph patterns, with prominent examples being insider infiltrations (path queries), denial of service (parallel paths) and malicious spreads (tree queries). This motivates us to explore subgraph matching on streaming graphs in amore » continuous setting. The novelty of our work lies in using the subgraph distributional statistics collected from the streaming graph to determine the query processing strategy. We introduce a ``Lazy Search" algorithm where the search strategy is decided on a vertex-to-vertex basis depending on the likelihood of a match in the vertex neighborhood. We also propose a metric named ``Relative Selectivity" that is used to select between different query processing strategies. Our experiments performed on real online news, network traffic stream and a synthetic social network benchmark demonstrate 10-100x speedups over non-incremental, selectivity agnostic approaches.« less

In house validation of a high resolution mass spectrometry Orbitrap-based method for multiple allergen detection in a processed model food.

PubMed

Pilolli, Rosa; De Angelis, Elisabetta; Monaci, Linda

2018-02-13

In recent years, mass spectrometry (MS) has been establishing its role in the development of analytical methods for multiple allergen detection, but most analyses are being carried out on low-resolution mass spectrometers such as triple quadrupole or ion traps. In this investigation, performance provided by a high resolution (HR) hybrid quadrupole-Orbitrap™ MS platform for the multiple allergens detection in processed food matrix is presented. In particular, three different acquisition modes were compared: full-MS, targeted-selected ion monitoring with data-dependent fragmentation (t-SIM/dd2), and parallel reaction monitoring. In order to challenge the HR-MS platform, the sample preparation was kept as simple as possible, limited to a 30-min ultrasound-aided protein extraction followed by clean-up with disposable size exclusion cartridges. Selected peptide markers tracing for five allergenic ingredients namely skim milk, whole egg, soy flour, ground hazelnut, and ground peanut were monitored in home-made cookies chosen as model processed matrix. Timed t-SIM/dd2 was found the best choice as a good compromise between sensitivity and accuracy, accomplishing the detection of 17 peptides originating from the five allergens in the same run. The optimized method was validated in-house through the evaluation of matrix and processing effects, recoveries, and precision. The selected quantitative markers for each allergenic ingredient provided quantification of 60-100 μg ingred /g allergenic ingredient/matrix in incurred cookies.

Highly efficient all-dielectric optical tensor impedance metasurfaces for chiral polarization control.

PubMed

Kim, Minseok; Eleftheriades, George V

2016-10-15

We propose a highly efficient (nearly lossless and impedance-matched) all-dielectric optical tensor impedance metasurface that mimics chiral effects at optical wavelengths. By cascading an array of rotated crossed silicon nanoblocks, we realize chiral optical tensor impedance metasurfaces that operate as circular polarization selective surfaces. Their efficiencies are maximized through a nonlinear numerical optimization process in which the tensor impedance metasurfaces are modeled via multi-conductor transmission line theory. From rigorous full-wave simulations that include all material losses, we show field transmission efficiencies of 94% for right- and left-handed circular polarization selective surfaces at 800 nm.

Behavior of pharmaceuticals in waste water treatment plant in Japan.

PubMed

Matsuo, H; Sakamoto, H; Arizono, K; Shinohara, R

2011-07-01

The fate of pharmaceuticals in a wastewater treatment plant (WWTP) in Kumamoto, Japan with activated sludge treatment is reported. Selected pharmaceuticals were detected in influent. Results from the present study confirmed that Acetaminophen, Amoxicillin, Ampicillin and Famotidine were removed at a high rate (>90% efficiency). In contrast, removal efficiency of Ketoprofen, Losartan, Oseltamivir, Carbamazepine, and Diclofenac was relatively low (<50%). The selected pharmaceuticals were also detected in raw sludge. In digestive process, Indomethacin, Atenolol, Famotidine, Trimethoprim and Cyclofosamide were removed at a high (>70% efficiency). On the other hand, removal of Carbamazepine, Ketoprofen and Diclofenac was not efficient (<50%).

Research on Correlation between Vehicle Cycle and Engine Cycle in Heavy-duty commercial vehicle

NASA Astrophysics Data System (ADS)

lin, Chen; Zhong, Wang; Shuai, Liu

2017-12-01

In order to study the correlation between vehicle cycle and engine cycle in heavy commercial vehicles, the conversion model of vehicle cycle to engine cycle is constructed based on the vehicle power system theory and shift strategy, which considers the verification on diesel truck. The results show that the model has high rationality and reliability in engine operation. In the acceleration process of high speed, the difference of model gear selection leads to the actual deviation. Compared with the drum test, the engine speed distribution obtained by the model deviates to right, which fits to the lower grade. The grade selection has high influence on the model.

State-selected chemical reaction dynamics at the S matrix level - Final-state specificities of near-threshold processes at low and high energies

NASA Technical Reports Server (NTRS)

Chatfield, David C.; Truhlar, Donald G.; Schwenke, David W.

1992-01-01

State-to-state reaction probabilities are found to be highly final-state specific at state-selected threshold energies for the reactions O + H2 yield OH + H and H + H2 yield H2 + H. The study includes initial rotational states with quantum numbers 0-15, and the specificity is especially dramatic for the more highly rotationally excited reactants. The analysis is based on accurate quantum mechanical reactive scattering calculations. Final-state specificity is shown in general to increase with the rotational quantum number of the reactant diatom, and the trends are confirmed for both zero and nonzero values of the total angular momentum.