WorldWideScience

Sample records for blue dots team

  1. Hubble's View of Little Blue Dots

    Science.gov (United States)

    Kohler, Susanna

    2018-02-01

    The recent discovery of a new type of tiny, star-forming galaxy is the latest in a zoo of detections shedding light on our early universe. What can we learn from the unique little blue dots found in archival Hubble data?Peas, Berries, and DotsGreen pea galaxies identified by citizen scientists with Galaxy Zoo. [Richard Nowell Carolin Cardamone]As telescope capabilities improve and we develop increasingly deeper large-scale surveys of our universe, we continue to learn more about small, faraway galaxies. In recent years, increasing sensitivity first enabled the detection of green peas luminous, compact, low-mass (10 billion solar masses; compare this to the Milky Ways 1 trillion solar masses!) galaxies with high rates of star formation.Not long thereafter, we discovered galaxies that form stars similarly rapidly, but are even smaller only 330 million solar masses, spanning less than 3,000 light-years in size. These tiny powerhouses were termed blueberries for their distinctive color.Now, scientists Debra and Bruce Elmegreen (of Vassar College and IBM Research Division, respectively) report the discovery of galaxies that have even higher star formation rates and even lower masses: little blue dots.Exploring Tiny Star FactoriesThe Elmegreens discovered these unique galaxies by exploring archival Hubble data. The Hubble Frontier Fields data consist of deep images of six distant galaxy clusters and the parallel fields next to them. It was in the archival data for two Frontier Field Parallels, those for clusters Abell 2744 and MAS J0416.1-2403, that the authors noticed several galaxies that stand out as tiny, bright, blue objects that are nearly point sources.Top: a few examples of the little blue dots recently identified in two Hubble Frontier Field Parallels. Bottom: stacked images for three different groups of little blue dots. [Elmegreen Elmegreen 2017]The authors performed a search through the two Frontier Field Parallels, discovering a total of 55 little blue dots

  2. Dot gain compensation in the blue noise mask

    Science.gov (United States)

    Yao, Meng; Parker, Kevin J.

    1995-04-01

    Frequency modulated (FM) halftoning or 'stochastic screening,' has attracted a great deal of attention in the printing industry in recent years. It has several advantages over conventional halftoning. But one serious problem that arises in FM halftoning is dot gain. One approach to stochastic screening uses a specially constructed halftone screen, the blue noise mask (BNM), to produce an unstructured and visually appealing pattern of halftone dots at any gray level. In this paper, we will present methods to correct dot gain with the BNM. Dot gain is related to the area-to-perimeter ration of printed spots. We can exploit this feature in different ways. At a medium level, a B>NM pattern will have 'connected' as well as 'isolated' dots. Normally, as we build down BNM patterns to lower levels, a specific number of white dots will be replace by black dots. Since connected white dots are more likely to be picked than isolated white dots, this will results in substantial dot gain because of the increasing number of isolated white dots. We show that it is possible to constrain the process of constructing a BNM such that isolated dots are preferentially removes, thus significantly reducing dot gain in a BNM.

  3. Code Blue Emergencies: A Team Task Analysis and Educational Initiative.

    Science.gov (United States)

    Price, James W; Applegarth, Oliver; Vu, Mark; Price, John R

    2012-01-01

    The objective of this study was to identify factors that have a positive or negative influence on resuscitation team performance during emergencies in the operating room (OR) and post-operative recovery unit (PAR) at a major Canadian teaching hospital. This information was then used to implement a team training program for code blue emergencies. In 2009/10, all OR and PAR nurses and 19 anesthesiologists at Vancouver General Hospital (VGH) were invited to complete an anonymous, 10 minute written questionnaire regarding their code blue experience. Survey questions were devised by 10 recovery room and operation room nurses as well as 5 anesthesiologists representing 4 different hospitals in British Columbia. Three iterations of the survey were reviewed by a pilot group of nurses and anesthesiologists and their feedback was integrated into the final version of the survey. Both nursing staff (n = 49) and anesthesiologists (n = 19) supported code blue training and believed that team training would improve patient outcome. Nurses noted that it was often difficult to identify the leader of the resuscitation team. Both nursing staff and anesthesiologists strongly agreed that too many people attending the code blue with no assigned role hindered team performance. Identifiable leadership and clear communication of roles were identified as keys to resuscitation team functioning. Decreasing the number of people attending code blue emergencies with no specific role, increased access to mock code blue training, and debriefing after crises were all identified as areas requiring improvement. Initial team training exercises have been well received by staff.

  4. Code Blue Emergencies: A Team Task Analysis and Educational Initiative

    Directory of Open Access Journals (Sweden)

    James W. Price

    2012-04-01

    Full Text Available Introduction: The objective of this study was to identify factors that have a positive or negative influence on resuscitation team performance during emergencies in the operating room (OR and post-operative recovery unit (PAR at a major Canadian teaching hospital. This information was then used to implement a team training program for code blue emergencies. Methods: In 2009/10, all OR and PAR nurses and 19 anesthesiologists at Vancouver General Hospital (VGH were invited to complete an anonymous, 10 minute written questionnaire regarding their code blue experience. Survey questions were devised by 10 recovery room and operation room nurses as well as 5 anesthesiologists representing 4 different hospitals in British Columbia. Three iterations of the survey were reviewed by a pilot group of nurses and anesthesiologists and their feedback was integrated into the final version of the survey. Results: Both nursing staff (n = 49 and anesthesiologists (n = 19 supported code blue training and believed that team training would improve patient outcome. Nurses noted that it was often difficult to identify the leader of the resuscitation team. Both nursing staff and anesthesiologists strongly agreed that too many people attending the code blue with no assigned role hindered team performance. Conclusion: Identifiable leadership and clear communication of roles were identified as keys to resuscitation team functioning. Decreasing the number of people attending code blue emergencies with no specific role, increased access to mock code blue training, and debriefing after crises were all identified as areas requiring improvement. Initial team training exercises have been well received by staff.

  5. 76 FR 22923 - Wellpoint, Inc. D/B/A/Anthem Blue Cross & Blue Shield Enterprise Provider Data Management Team...

    Science.gov (United States)

    2011-04-25

    .../B/A/Anthem Blue Cross & Blue Shield Enterprise Provider Data Management Team Including On-Site... & Blue Shield, Enterprise Provider Data Management Team, Including On-Site Leased Workers From Kelly... Of Kentucky, Enterprise Provider Data Management Team, Louisville, Kentucky TA-W-74,895B Wellpoint...

  6. Freestanding silicon quantum dots: origin of red and blue luminescence.

    Science.gov (United States)

    Gupta, Anoop; Wiggers, Hartmut

    2011-02-04

    In this paper, we studied the behavior of silicon quantum dots (Si-QDs) after etching and surface oxidation by means of photoluminescence (PL) measurements, Fourier transform infrared spectroscopy (FTIR) and electron paramagnetic resonance spectroscopy (EPR). We observed that etching of red luminescing Si-QDs with HF acid drastically reduces the concentration of defects and significantly enhances their PL intensity together with a small shift in the emission spectrum. Additionally, we observed the emergence of blue luminescence from Si-QDs during the re-oxidation of freshly etched particles. Our results indicate that the red emission is related to the quantum confinement effect, while the blue emission from Si-QDs is related to defect states at the newly formed silicon oxide surface.

  7. Facile synthetic method for pristine graphene quantum dots and graphene oxide quantum dots: origin of blue and green luminescence.

    Science.gov (United States)

    Liu, Fei; Jang, Min-Ho; Ha, Hyun Dong; Kim, Je-Hyung; Cho, Yong-Hoon; Seo, Tae Seok

    2013-07-19

    Pristine graphene quantum dots and graphene oxide quantum dots are synthesized by chemical exfoliation from the graphite nanoparticles with high uniformity in terms of shape (circle), size (less than 4 nm), and thickness (monolayer). The origin of the blue and green photoluminescence of GQDs and GOQDs is attributed to intrinsic and extrinsic energy states, respectively. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. High-level methodology for carrying out combined red and blue teams

    CSIR Research Space (South Africa)

    Veerasamy, N

    2009-12-01

    Full Text Available This paper proposes a combined Red and Blue Team Methodology to guide the process of carrying out such security auditing and penetration testing tasks. Red and Blue Teams consist of various security auditing and penetration testing tasks which serve...

  9. Synthesis of blue photoluminescent WS2 quantum dots via ultrasonic cavitation

    International Nuclear Information System (INIS)

    Bayat, A.; Saievar-Iranizad, E.

    2017-01-01

    Blue photoluminescent WS 2 quantum dots (QDs) were synthesized using a simple top-down method from natural raw mineral tungsten disulfide via tip ultrasonication followed by centrifugation in a water-ethanol (0.7/0.3 ratio) as eco-friendly solvent. Cavitation process at a high power (300 W) led to the breaking of bulk WS 2 flakes to its quantum dots. The as synthesized WS 2 QDs showed blue photoluminescence upon UV excitation. The synthesized WS 2 QDs were analysed by UV–vis and photoluminescence spectrophotometry, transmission electron microscopy, atomic force microscopy and X-ray diffraction. According to the transmission electron microscopy images, the size of WS 2 QDs was obtained as 5 nm in average. - Highlights: •Large scale blue photoluminescent WS 2 quantum dots was synthesized using Ultrasonic probe (Cavitation Process). •A solution of water/ethanol (0.7/0.3) was used as eco-friendly solvent instead of unsuitable solvent such as NMP and ACN. •Edges of bulk WS 2 was increased with formation of its quantum dots. •Solution of WS 2 QDs was stable after 6 months.

  10. Synthesis of blue photoluminescent WS{sub 2} quantum dots via ultrasonic cavitation

    Energy Technology Data Exchange (ETDEWEB)

    Bayat, A.; Saievar-Iranizad, E., E-mail: saievare@modares.ac.ir

    2017-05-15

    Blue photoluminescent WS{sub 2} quantum dots (QDs) were synthesized using a simple top-down method from natural raw mineral tungsten disulfide via tip ultrasonication followed by centrifugation in a water-ethanol (0.7/0.3 ratio) as eco-friendly solvent. Cavitation process at a high power (300 W) led to the breaking of bulk WS{sub 2} flakes to its quantum dots. The as synthesized WS{sub 2} QDs showed blue photoluminescence upon UV excitation. The synthesized WS{sub 2} QDs were analysed by UV–vis and photoluminescence spectrophotometry, transmission electron microscopy, atomic force microscopy and X-ray diffraction. According to the transmission electron microscopy images, the size of WS{sub 2} QDs was obtained as 5 nm in average. - Highlights: •Large scale blue photoluminescent WS{sub 2} quantum dots was synthesized using Ultrasonic probe (Cavitation Process). •A solution of water/ethanol (0.7/0.3) was used as eco-friendly solvent instead of unsuitable solvent such as NMP and ACN. •Edges of bulk WS{sub 2} was increased with formation of its quantum dots. •Solution of WS{sub 2} QDs was stable after 6 months.

  11. Synthesis and characterization of small size fluorescent LEEH caped blue emission ZnTe quantum dots

    Directory of Open Access Journals (Sweden)

    Patnaik Sumanta Kumar

    2017-04-01

    Full Text Available We report here for the first time the synthesis of LEEH caped very small size (2 nm ZnTe quantum dots at low temperature (less than 100 °C using a simple chemical route. The effects of aging and stirring time on the absorption spectra of the quantum dots were investigated. The synthesized nanocrystal (NC was characterized by PL, TEM, XRD and the formation of very small size quantum dots having FCC structure was confirmed. Further, blue emission from the prepared sample was observed during exposure to monochromatic UV radiation. ZnTe NCs obtained in this study were found to be more stable compared to those presented in literature reports. ZnTe NCs may be considered as a new material in place of CdTe for optoelectronics devices.

  12. Layer-by-layer assembly of multicolored semiconductor quantum dots towards efficient blue, green, red and full color optical films

    International Nuclear Information System (INIS)

    Zhang Jun; Li Qian; Di Xiaowei; Liu Zhiliang; Xu Gang

    2008-01-01

    Multicolored semiconductor quantum dots have shown great promise for construction of miniaturized light-emitting diodes with compact size, low weight and cost, and high luminescent efficiency. The unique size-dependent luminescent property of quantum dots offers the feasibility of constructing single-color or full-color output light-emitting diodes with one type of material. In this paper, we have demonstrated the facile fabrication of blue-, green-, red- and full-color-emitting semiconductor quantum dot optical films via a layer-by-layer assembly technique. The optical films were constructed by alternative deposition of different colored quantum dots with a series of oppositely charged species, in particular, the new use of cationic starch on glass substrates. Semiconductor ZnSe quantum dots exhibiting blue emission were deposited for fabrication of blue-emitting optical films, while semiconductor CdTe quantum dots with green and red emission were utilized for construction of green- and red-emitting optical films. The assembly of integrated blue, green and red semiconductor quantum dots resulted in full-color-emitting optical films. The luminescent optical films showed very bright emitting colors under UV irradiation, and displayed dense, smooth and efficient luminous features, showing brighter luminescence in comparison with their corresponding quantum dot aqueous colloid solutions. The assembled optical films provide the prospect of miniaturized light-emitting-diode applications.

  13. Connecting the dots : supporting the implementation of teacher design teams

    NARCIS (Netherlands)

    Binkhorst, Floor

    2017-01-01

    In Teacher Design Teams (TDTs), teachers collaborate on (re)designing educational materials. Although several studies have shown that TDTs can contribute to teachers’ professional development, as well as to sustainable implementation of educational change by using the educational materials they

  14. Graphene quantum dot synthesis using nanosecond laser pulses and its comparison to Methylene Blue

    Science.gov (United States)

    Kholikov, Khomidkhodza; Thomas, Zachary; Seyitliyev, Dovletgeldi; Smith, Skylar

    A biocompatible photodynamic therapy agent that generates a high amount of singlet oxygen with high water dispersibility and excellent photostability is desirable. In this work, a graphene based biomaterial which is a promising alternative to a standard photosensitizers was produced. Methylene blue was used as a reference photosensitizer. Bacteria deactivation by methylene blue was shown to be inhibited inside human blood due to protein binding. Graphene quantum dots (GQD) were synthesized by irradiating benzene and nickel oxide mixture using nanosecond laser pulses. High resolution transmission electron microscopy (HR-TEM), scanning electron microscopy (SEM), atomic force microscopy (AFM), Fourier transform infrared (FTIR) spectroscopy, and nuclear magnetic resonance (NMR) were used for characterization of GQDs. Initial results show graphene quantum dots whose size less than 5 nm were successfully obtained. UV-VIS spectra shows absorption peak around 310 nm. The results of these studies can potentially be used to develop therapies for the eradication of pathogens in open wounds, burns, or skin cancers. New therapies for these conditions are particularly needed when antibiotic-resistant infections are present. NIH KBRIN.

  15. A sol-gel method for preparing ZnO quantum dots with strong blue emission

    International Nuclear Information System (INIS)

    Chen Zhong; Li Xiaoxia; Du Guoping; Chen Nan; Suen, Andy Y.M.

    2011-01-01

    ZnO quantum dots (QDs) with strong blue emission have been successfully synthesized by sol-gel method, and their crystal structures, sizes, and photoluminescence properties were characterized by X-ray diffractometer, scanning electron microscope, and ultraviolet-visible spectroscopy. It has been found that ZnO QDs had a hexagonal wurtzite crystal structure, and their average diameter was about 16.0-32.2 nm. Both the reaction time and temperature were found to have a strong influence on the average size and photoluminescence properties of ZnO QDs. Longer reaction time and higher reaction temperature resulted in larger average size for ZnO QDs. It has been shown that at reaction temperature 60 deg. C the emission intensity for ZnO QDs increased first with reaction time before 7 h and then decreased after 7 h. For the same reaction time 7 h, ZnO QDs synthesized at 60 deg. C showed the strongest emission intensity. It was found that annealing in nitrogen, vacuum, and air all resulted in an increase of the size of ZnO QDs and a reduction in their photoluminescence. The dependence of the size and properties of ZnO QDs on the reaction parameters as well as the annealing conditions has been discussed. - Highlights: → ZnO quantum dots (QDs) with strong blue emission were prepared by sol-gel method. → ZnO QDs had a pure spectral blue with the chromaticity coordinates (0.166, 0.215). → Optimal reaction time and temperature were 7 h and 60 deg. C, respectively.

  16. Synthesis and Properties of Water-Soluble Blue-Emitting Mn-Alloyed CdTe Quantum Dots

    Science.gov (United States)

    Tynkevych, Olena; Karavan, Volodymyr; Vorona, Igor; Filonenko, Svitlana; Khalavka, Yuriy

    2018-05-01

    In this work, we prepared CdTe quantum dots, and series of Cd1-xMnxTe-alloyed quantum dots with narrow size distribution by an ion-exchange reaction in water solution. We found that the photoluminescence peaks are shifted to higher energies with the increasing Mn2+ content. So far, this is the first report of blue-emitting CdTe-based quantum dots. By means of cyclic voltammetry, we detected features of electrochemical activity of manganese energy levels formed inside the Cd1-xMnxTe-alloyed quantum dot band gap. This allowed us to estimate their energy position. We also demonstrate paramagnetic behavior for Cd1-xMnxTe-alloyed quantum dots which confirmed the successful ion-exchange reaction.

  17. Synthesis and Properties of Water-Soluble Blue-Emitting Mn-Alloyed CdTe Quantum Dots.

    Science.gov (United States)

    Tynkevych, Olena; Karavan, Volodymyr; Vorona, Igor; Filonenko, Svitlana; Khalavka, Yuriy

    2018-05-02

    In this work, we prepared CdTe quantum dots, and series of Cd 1-x Mn x Te-alloyed quantum dots with narrow size distribution by an ion-exchange reaction in water solution. We found that the photoluminescence peaks are shifted to higher energies with the increasing Mn 2+ content. So far, this is the first report of blue-emitting CdTe-based quantum dots. By means of cyclic voltammetry, we detected features of electrochemical activity of manganese energy levels formed inside the Cd 1-x Mn x Te-alloyed quantum dot band gap. This allowed us to estimate their energy position. We also demonstrate paramagnetic behavior for Cd 1-x Mn x Te-alloyed quantum dots which confirmed the successful ion-exchange reaction.

  18. Microscopic origin of the fast blue-green luminescence of chemically synthesized non-oxidized silicon quantum dots

    NARCIS (Netherlands)

    Dohnalova, K.; Fucikova, A.; Umesh, C.P.; Humpolickova, J.; Paulusse, Jos Marie Johannes; Valenta, J.; Zuilhof, H.

    2012-01-01

    The microscopic origin of the bright nanosecond blue-green photoluminescence (PL), frequently reported for synthesized organically terminated Si quantum dots (Si-QDs), has not been fully resolved, hampering potential applications of this interesting material. Here a comprehensive study of the PL

  19. Microscopic Origin of the Fast Blue-Green Luminescence from Chemically Synthesized Non-Oxidized Silicon Quantum Dots

    NARCIS (Netherlands)

    Dohnalová, K.; Gregorkiewicz, T.; Fucíková, A.; Valenta, J.; Umesh, C.; Paulusse, J.M.J.; Zuilhof, H.; Humpolícková, J.; Hof, van M.

    2012-01-01

    The microscopic origin of the bright nanosecond blue-green photoluminescence (PL), frequently reported for synthesized organically terminated Si quantum dots (Si-QDs), has not been fully resolved, hampering potential applications of this interesting material. Here a comprehensive study of the PL

  20. Code Team Training: Demonstrating Adherence to AHA Guidelines During Pediatric Code Blue Activations.

    Science.gov (United States)

    Stewart, Claire; Shoemaker, Jamie; Keller-Smith, Rachel; Edmunds, Katherine; Davis, Andrew; Tegtmeyer, Ken

    2017-10-16

    Pediatric code blue activations are infrequent events with a high mortality rate despite the best effort of code teams. The best method for training these code teams is debatable; however, it is clear that training is needed to assure adherence to American Heart Association (AHA) Resuscitation Guidelines and to prevent the decay that invariably occurs after Pediatric Advanced Life Support training. The objectives of this project were to train a multidisciplinary, multidepartmental code team and to measure this team's adherence to AHA guidelines during code simulation. Multidisciplinary code team training sessions were held using high-fidelity, in situ simulation. Sessions were held several times per month. Each session was filmed and reviewed for adherence to 5 AHA guidelines: chest compression rate, ventilation rate, chest compression fraction, use of a backboard, and use of a team leader. After the first study period, modifications were made to the code team including implementation of just-in-time training and alteration of the compression team. Thirty-eight sessions were completed, with 31 eligible for video analysis. During the first study period, 1 session adhered to all AHA guidelines. During the second study period, after alteration of the code team and implementation of just-in-time training, no sessions adhered to all AHA guidelines; however, there was an improvement in percentage of sessions adhering to ventilation rate and chest compression rate and an improvement in median ventilation rate. We present a method for training a large code team drawn from multiple hospital departments and a method of assessing code team performance. Despite subjective improvement in code team positioning, communication, and role completion and some improvement in ventilation rate and chest compression rate, we failed to consistently demonstrate improvement in adherence to all guidelines.

  1. Pale blue dot a vision of the human future in space

    CERN Document Server

    Sagan, Carl

    1994-01-01

    In Cosmos, the late astronomer Carl Sagan cast his gaze over the magnificent mystery of the Universe and made it accessible to millions of people around the world. Now in this stunning sequel, Carl Sagan completes his revolutionary journey through space and time. Future generations will look back on our epoch as the time when the human race finally broke into a radically new frontier--space. In Pale Blue Dot Sagan traces the spellbinding history of our launch into the cosmos and assesses the future that looms before us as we move out into our own solar system and on to distant galaxies beyond. The exploration and eventual settlement of other worlds is neither a fantasy nor luxury, insists Sagan, but rather a necessary condition for the survival of the human race.

  2. Magnetic enhancement of photoluminescence from blue-luminescent graphene quantum dots

    Science.gov (United States)

    Chen, Qi; Shi, Chentian; Zhang, Chunfeng; Pu, Songyang; Wang, Rui; Wu, Xuewei; Wang, Xiaoyong; Xue, Fei; Pan, Dengyu; Xiao, Min

    2016-02-01

    Graphene quantum-dots (GQDs) have been predicted and demonstrated with fascinating optical and magnetic properties. However, the magnetic effect on the optical properties remains experimentally unexplored. Here, we conduct a magneto-photoluminescence study on the blue-luminescence GQDs at cryogenic temperatures with magnetic field up to 10 T. When the magnetic field is applied, a remarkable enhancement of photoluminescence emission has been observed together with an insignificant change in circular polarization. The results have been well explained by the scenario of magnetic-field-controlled singlet-triplet mixing in GQDs owing to the Zeeman splitting of triplet states, which is further verified by temperature-dependent experiments. This work uncovers the pivotal role of intersystem crossing in GQDs, which is instrumental for their potential applications such as light-emitting diodes, photodynamic therapy, and spintronic devices.

  3. Enhanced Training for Cyber Situational Awareness in Red versus Blue Team Exercises

    Energy Technology Data Exchange (ETDEWEB)

    Carbajal, Armida J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Human Factors and Statistics; Stevens-Adams, Susan Marie [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Risk and Reliability Analysis; Silva, Austin Ray [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Cognitive Modeling; Nauer, Kevin S. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Cyber Security Technologies; Anderson, Benjamin Robert [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Assurance Technologies and Assessment; Forsythe, James Chris [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Cognitive Modeling

    2012-09-01

    This report summarizes research conducted through the Sandia National Laboratories Enhanced Training for Cyber Situational Awareness in Red Versus Blue Team Exercises Laboratory Directed Research and Development project. The objective of this project was to advance scientific understanding concerning how to best structure training for cyber defenders. Two modes of training were considered. The baseline training condition (Tool-Based training) was based on current practices where classroom instruction focuses on the functions of a software tool with various exercises in which students apply those functions. In the second training condition (Narrative-Based training), classroom instruction addressed software functions, but in the context of adversary tactics and techniques. It was hypothesized that students receiving narrative-based training would gain a deeper conceptual understanding of the software tools and this would be reflected in better performance within a red versus blue team exercise.

  4. Blue and green electroluminescence from CdSe nanocrystal quantum-dot-quantum-wells

    International Nuclear Information System (INIS)

    Lu, Y. F.; Cao, X. A.

    2014-01-01

    CdS/CdSe/ZnS quantum dot quantum well (QDQW) nanocrystals were synthesized using the successive ion layer adsorption and reaction technique, and their optical properties were tuned by bandgap and strain engineering. 3-monolayer (ML) CdSe QWs emitted blue photoluminescence at 467 nm with a spectral full-width-at-half-maximum of ∼30 nm. With a 3 ML ZnS cladding layer, which also acts as a passivating and strain-compensating layer, the QDQWs acquired a ∼35% quantum yield of the QW emission. Blue and green electroluminescence (EL) was obtained from QDQW light-emitting devices with 3–4.5 ML CdSe QWs. It was found that as the peak blueshifted, the overall EL was increasingly dominated by defect state emission due to poor hole injection into the QDQWs. The weak EL was also attributed to strong field-induced charge separation resulting from the unique QDQW geometry, weakening the oscillator strength of optical transitions

  5. On the origin of blue emission from ZnO quantum dots synthesized by a sol–gel route

    International Nuclear Information System (INIS)

    Han, Li-Li; Cui, Lan; Du, Xi-Wen; Wang, Wei-Hua; Wang, Jiang-Long

    2012-01-01

    ZnO quantum dots (QDs) with blue emission were synthesized by a sol–gel method. A series of control experiments were conducted to explore the origin of the blue emission. It is found that the blue emission arises from neither the quantum confinement nor intermediate products, and it can be achieved only in the presence of Li + cations and excessive OH − anions. Moreover, the long decay time of the blue emission suggests a defect-related de-excitation process. On the basis of the experimental and calculation results, possible de-excitation paths for light emission were discussed, and the origin of the blue emission was determined as the electron transition from the conduction band to interstitial oxygen defects. Excessive OH − anions are responsible for the formation of interstitial oxygen defects, and Li + ions can stabilize the defects by substituting for Zn atoms. Besides, Li + ions can block the growth of ZnO QDs, broaden their band gap and cause a blue shift of the blue emission. (paper)

  6. Synthesis of blue emitting InP/ZnS quantum dots through control of competition between etching and growth

    International Nuclear Information System (INIS)

    Lim, Kipil; Jang, Ho Seong; Woo, Kyoungja

    2012-01-01

    Blue (<480 nm) emitting Cd-free quantum dots (QDs) are in great demand for various applications. However, their synthesis has been challenging. Here we present blue emitting InP/ZnS core/shell QDs with a band edge emission of 475 nm and a full width at half maximum of 39 nm (215 meV) from their quantum confined states. The drastic temperature drop immediately after mixing of the precursors and holding them at a temperature below 150 °C was the critical factor for the synthesis of blue emitting QDs, because the blue QDs are formed by the etching of ultra-small InP cores by residual acetic acid below 150 °C. Etching was dominant at temperatures below 150 °C, whereas growth was dominant at temperatures above 150 °C. ZnS shells were formed successfully at 150 °C, yielding blue emitting InP/ZnS QDs. The colour of the InP/ZnS QDs depicted on the CIE 1931 chromaticity diagram is located close to the edge, indicating a pure blue colour compared to other InP-based QDs. (paper)

  7. Intense, stable and excitation wavelength-independent photoluminescence emission in the blue-violet region from phosphorene quantum dots

    Science.gov (United States)

    Ge, Shuaipeng; Zhang, Lisheng; Wang, Peijie; Fang, Yan

    2016-01-01

    Nanoscale phosphorene quantum dots (PQDs) with few-layer structures were fabricated by pulsed laser ablation of a bulk black phosphorus target in diethyl ether. An intense and stable photoluminescence (PL) emission of the PQDs in the blue-violet wavelength region is clearly observed for the first time, which is attributed to electronic transitions from the lowest unoccupied molecular orbital (LUMO) to the highest occupied molecular orbital (HOMO) and occupied molecular orbitals below the HOMO (H-1, H-2), respectively. Surprisingly, the PL emission peak positions of the PQDs are not red-shifted with progressively longer excitation wavelengths, which is in contrast to the cases of graphene and molybdenum disulphide quantum dots. This excitation wavelength-independence is derived from the saturated passivation on the periphery and surfaces of the PQDs by large numbers of electron-donating functional groups which cause the electron density on the PQDs to be dramatically increased and the band gap to be insensitive to the quantum size effect in the PQDs. This work suggests that PQDs with intense, stable and excitation wavelength-independent PL emission in the blue-violet region have a potential application as semiconductor-based blue-violet light irradiation sources. PMID:27265198

  8. The pale blue dot a vision of the human future in space uma experiência tradutória

    OpenAIRE

    Matos, Bruno Fernandes Belchior de

    2015-01-01

    O presente Projeto de Mestrado na área de Estudos de Tradução tem por objetivo apresentar uma proposta de tradução comparativa comentada para Português Europeu da seleção de quatro capítulos da obra divulgadora de ciência The Pale Blue Dot – A vision of the human future in space, escrito em 1994 e da autoria de Carl Sagan. Pretende-se dividir este trabalho em dois capítulos distintos. No primeiro capítulo será feita uma breve abordagem autobiográfica do autor da obra, o percurs...

  9. The (Un)Lonely Planet Guide: Formation and Evolution of Planetary Systems from a ``Blue Dots'' Perspective

    Science.gov (United States)

    Meyer, M. R.

    2010-10-01

    In this contribution I summarize some recent successes, and focus on remaining challenges, in understanding the formation and evolution of planetary systems in the context of the Blue Dots initiative. Because our understanding is incomplete, we cannot yet articulate a design reference mission engineering matrix suitable for an exploration mission where success is defined as obtaining a spectrum of a potentially habitable world around a nearby star. However, as progress accelerates, we can identify observational programs that would address fundamental scientific questions through hypothesis testing such that the null result is interesting.

  10. Fabrication of blue luminescent MoS{sub 2} quantum dots by wet grinding assisted co-solvent sonication

    Energy Technology Data Exchange (ETDEWEB)

    Ali, Junaid; Siddiqui, Ghayas Uddin [Department of Mechatronics Engineering, Jeju National University, Jeju (Korea, Republic of); Choi, Kyung Hyun, E-mail: amm@jejunu.ac.kr [Department of Mechatronics Engineering, Jeju National University, Jeju (Korea, Republic of); Jang, Yunseok [Department of Printed Electronics, Korea Institute of Machinery & Materials, Daejeon, Republic of Korea (Korea, Republic of); Lee, Kangtaek [Department of Chemical and Biomolecular Engineering, Yonsei University (Korea, Republic of)

    2016-01-15

    Molybdenum disulfide (MoS{sub 2}) belongs to transition-metal dichalcogenides (TMDs) family and has vital position among 2D materials. Here, an efficient strategy for the synthesis of zero-dimensional MoS{sub 2} quantum dots (QDs) has been represented. This strategy consists of wet grinding of pristine MoS{sub 2} in N-methyl-2-pyrrolidone (NMP) followed by sonication in NMP and 1,2-dichlorobenzene (o-DCB). The efficacy of this approach to synthesize MoS{sub 2} QDs has been reported by analyzing the as synthesized MoS{sub 2} QDs by different characterization techniques such as high resolution transmission electron microscopy, energy dispersive x-ray spectroscopy, Raman spectroscopy, photoluminescence spectroscopy, Fourier transform infrared spectroscopy and UV–vis spectroscopy. The concentration (yield) of as synthesized MoS{sub 2} QDs was found to be 7 mg mL{sup −1}. Most of the MoS{sub 2} QDs were measured around 2–5 nm in size. The as synthesized MoS{sub 2} QDs showed distinct blue luminescence upon UV excitation. - Highlights: • Synthesis of MoS{sub 2} quantum dots. • Wet grinding of MoS{sub 2} flakes for 6 h in NMP. • Ultrasonication of MoS{sub 2} in NMP and DCB. • Particle size 2–5 nm and concentration 7 mg/ml. • MoS{sub 2} QDs showed blue luminescence.

  11. Origin of the ESR spectrum in the Prussian blue analog RbMn[Fe(CN)(6)]center dot H2O

    NARCIS (Netherlands)

    Antal, A.; Janossy, A.; Forro, L.; Vertelman, E. J. M.; van Koningsbruggen, P. J.; van Loosdrecht, P. H. M.

    2010-01-01

    We present an electron spin resonance (ESR) study at excitation frequencies of 9.4 and 222.4 GHz of powders and single crystals of a Prussian blue analog (PBA), RbMn[Fe(CN)(6)]center dot H2O in which Fe and Mn undergoes a charge-transfer transition between 175 and 300 K. The ESR of PBA powders, also

  12. Microscopic origin of the fast blue-green luminescence of chemically synthesized non-oxidized silicon quantum dots.

    Science.gov (United States)

    Dohnalová, Kateřina; Fučíková, Anna; Umesh, Chinnaswamy P; Humpolíčková, Jana; Paulusse, Jos M J; Valenta, Jan; Zuilhof, Han; Hof, Martin; Gregorkiewicz, Tom

    2012-10-22

    The microscopic origin of the bright nanosecond blue-green photoluminescence (PL), frequently reported for synthesized organically terminated Si quantum dots (Si-QDs), has not been fully resolved, hampering potential applications of this interesting material. Here a comprehensive study of the PL from alkyl-terminated Si-QDs of 2-3 nm size, prepared by wet chemical synthesis is reported. Results obtained on the ensemble and those from the single nano-object level are compared, and they provide conclusive evidence that efficient and tunable emission arises due to radiative recombination of electron-hole pairs confined in the Si-QDs. This understanding paves the way towards applications of chemical synthesis for the development of Si-QDs with tunable sizes and bandgaps. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Little Blue Dots in the Hubble Space Telescope Frontier Fields: Precursors to Globular Clusters?

    Science.gov (United States)

    Elmegreen, Debra Meloy; Elmegreen, Bruce G.

    2017-12-01

    Galaxies with stellar masses {10}-7.4 yr‑1 were examined on images of the Hubble Space Telescope Frontier Field Parallels for Abell 2744 and MACS J0416.1-02403. They appear as unresolved “Little Blue Dots” (LBDs). They are less massive and have higher specific star formation rates (sSFRs) than “blueberries” studied by Yang et al. and higher sSFRs than “Blue Nuggets” studied by Tacchella et al. We divided the LBDs into three redshift bins and, for each, stacked the B435, V606, and I814 images convolved to the same stellar point-spread function (PSF). Their radii were determined from PSF deconvolution to be ∼80 to ∼180 pc. The high sSFRs suggest that their entire stellar mass has formed in only 1% of the local age of the universe. The sSFRs at similar epochs in local dwarf galaxies are lower by a factor of ∼100. Assuming that the star formation rate is {ε }{ff}{M}{gas}/{t}{ff} for efficiency {ε }{ff}, gas mass M gas, and free-fall time, t ff, the gas mass and gas-to-star mass ratio are determined. This ratio exceeds 1 for reasonable efficiencies, and is likely to be ∼5 even with a high {ε }{ff} of 0.1. We consider whether these regions are forming today’s globular clusters. With their observed stellar masses, the maximum likely cluster mass is ∼ {10}5 {M}ȯ , but if star formation continues at the current rate for ∼ 10{t}{ff}∼ 50 {Myr} before feedback and gas exhaustion stop it, then the maximum cluster mass could become ∼ {10}6 {M}ȯ .

  14. High Quantum Yield Blue Emission from Lead-Free Inorganic Antimony Halide Perovskite Colloidal Quantum Dots.

    Science.gov (United States)

    Zhang, Jian; Yang, Ying; Deng, Hui; Farooq, Umar; Yang, Xiaokun; Khan, Jahangeer; Tang, Jiang; Song, Haisheng

    2017-09-26

    Colloidal quantum dots (QDs) of lead halide perovskite have recently received great attention owing to their remarkable performances in optoelectronic applications. However, their wide applications are hindered from toxic lead element, which is not environment- and consumer-friendly. Herein, we utilized heterovalent substitution of divalent lead (Pb 2+ ) with trivalent antimony (Sb 3+ ) to synthesize stable and brightly luminescent Cs 3 Sb 2 Br 9 QDs. The lead-free, full-inorganic QDs were fabricated by a modified ligand-assisted reprecipitation strategy. A photoluminescence quantum yield (PLQY) was determined to be 46% at 410 nm, which was superior to that of other reported halide perovskite QDs. The PL enhancement mechanism was unraveled by surface composition derived quantum-well band structure and their large exciton binding energy. The Br-rich surface and the observed 530 meV exciton binding energy were proposed to guarantee the efficient radiative recombination. In addition, we can also tune the inorganic perovskite QD (Cs 3 Sb 2 X 9 ) emission wavelength from 370 to 560 nm via anion exchange reactions. The developed full-inorganic lead-free Sb-perovskite QDs with high PLQY and stable emission promise great potential for efficient emission candidates.

  15. Hydrothermal synthesis of highly luminescent blue-emitting ZnSe(S) quantum dots exhibiting low toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Mirnajafizadeh, Fatemeh; Ramsey, Deborah; McAlpine, Shelli [School of Chemistry, University of New South Wales, Sydney, NSW 2052 (Australia); Wang, Fan; Reece, Peter [School of Physics, University of New South Wales, Sydney, NSW 2052 (Australia); Stride, John Arron, E-mail: j.stride@unsw.edu.au [School of Chemistry, University of New South Wales, Sydney, NSW 2052 (Australia); Bragg Institute, Australian Nuclear Science and Technology Organisation, PMB 1, Menai, NSW 2234 (Australia)

    2016-07-01

    Highly luminescent quantum dots (QDs) that emit in the visible spectrum are of interest to a number of imaging technologies, not least that of biological samples. One issue that hinders the application of luminescent markers in biology is the potential toxicity of the fluorophore. Here we show that hydrothermally synthesized ZnSe(S) QDs have low cytotoxicity to both human colorectal carcinoma cells (HCT-116) and human skin fibroblast cells (WS1). The QDs exhibited a high degree of crystallinity, with a strong blue photoluminescence at up to 29% quantum yield relative to 4′,6-diamidino-2-phenylindole (DAPI) without post-synthetic UV-irradiation. Confocal microscopy images obtained of HCT-116 cells after incubation with the QDs highlighted the stability of the particles in cell media. Cytotoxicity studies showed that both HCT-116 and WS1 cells retain 100% viability after treatment with the QDs at concentrations up to 0.5 g/L, which makes them of potential use in biological imaging applications. - Highlights: • Highly luminescent ZnSe(S) QDs were synthesized using a simple, one-step hydrothermal method. • The as-synthesized QDs were found to be nontoxic in the presence of biological cells. • The QDs were stable in biological media with identical emission profile to that in water.

  16. Green and fast synthesis of amino-functionalized graphene quantum dots with deep blue photoluminescence

    Energy Technology Data Exchange (ETDEWEB)

    Blanco, E., E-mail: eduardo.blanco@uca.es; Blanco, G.; Gonzalez-Leal, J. M.; Barrera, M. C.; Domínguez, M.; Ramirez-del-Solar, M. [University of Cádiz, Institute of Electron Microscopy and Materials (Spain)

    2015-05-15

    Graphene quantum dots (GQDs) were prepared using a top-down approach with a green microwave-assisted hydrothermal synthesis from ultrathin graphite, previously ultrasound delaminated. Results obtained by transmission electron microscopy and atomic force microscopy indicate that the so-fabricated GQDs are plates with 6 nm of average diameter, mostly single- or bi-layered. Photoluminescence characterization shows that the strongest emission occurs at 410–415 nm wavelength when the samples are excited at 310–320 nm wavelength. In addition to these down-conversion features, GQDs also exhibit up-conversion photoluminescence when excited in the range 560–800 nm wavelength, with broad emission peaks at 410–450 nm wavelength. Analysis of X-ray photoelectron spectroscopy measurements indicates a higher proportion of C–C sp{sup 2} than sp{sup 3} bonds, with the sp{sup 3} ones mainly located at the GQD surfaces. Also evidences of C–O and C–N bonds at the GQD surface have been observed. The combination of these results with Raman and ultraviolet–visible absorption experiments allows envisaging the GQDs to be composed of amino-functionalized sp{sup 2} islands with a high degree of surface oxidation. This would explain the photoluminescent properties observed in the samples under study. The combined up- and down-conversion photoluminescence processes would made these GQDs a powerful energy-transfer component in GQDs–TiO{sub 2} nanocomposite systems, which could be used in photocatalyst devices with superior performance compared to simple TiO{sub 2} systems.

  17. TEAM.

    Science.gov (United States)

    National Highway Traffic Safety Administration (DOT), Washington, DC.

    This document presents materials covering the television campaign against drunk driving called "TEAM" (Techniques for Effective Alcohol Management). It is noted that TEAM's purpose is to promote effective alcohol management in public facilities and other establishments that serve alcoholic beverages. TEAM sponsors are listed, including…

  18. Synthesis of blue emitting InP/ZnS quantum dots through control of competition between etching and growth.

    Science.gov (United States)

    Lim, Kipil; Jang, Ho Seong; Woo, Kyoungja

    2012-12-07

    Blue (InP/ZnS core/shell QDs with a band edge emission of 475 nm and a full width at half maximum of 39 nm (215 meV) from their quantum confined states. The drastic temperature drop immediately after mixing of the precursors and holding them at a temperature below 150 °C was the critical factor for the synthesis of blue emitting QDs, because the blue QDs are formed by the etching of ultra-small InP cores by residual acetic acid below 150 °C. Etching was dominant at temperatures below 150 °C, whereas growth was dominant at temperatures above 150 °C. ZnS shells were formed successfully at 150 °C, yielding blue emitting InP/ZnS QDs. The colour of the InP/ZnS QDs depicted on the CIE 1931 chromaticity diagram is located close to the edge, indicating a pure blue colour compared to other InP-based QDs.

  19. Synthesis of blue emitting InP/ZnS quantum dots through control of competition between etching and growth

    Science.gov (United States)

    Lim, Kipil; Jang, Ho Seong; Woo, Kyoungja

    2012-12-01

    Blue (InP/ZnS core/shell QDs with a band edge emission of 475 nm and a full width at half maximum of 39 nm (215 meV) from their quantum confined states. The drastic temperature drop immediately after mixing of the precursors and holding them at a temperature below 150 °C was the critical factor for the synthesis of blue emitting QDs, because the blue QDs are formed by the etching of ultra-small InP cores by residual acetic acid below 150 °C. Etching was dominant at temperatures below 150 °C, whereas growth was dominant at temperatures above 150 °C. ZnS shells were formed successfully at 150 °C, yielding blue emitting InP/ZnS QDs. The colour of the InP/ZnS QDs depicted on the CIE 1931 chromaticity diagram is located close to the edge, indicating a pure blue colour compared to other InP-based QDs.

  20. C8-structured carbon quantum dots: Synthesis, blue and green double luminescence, and origins of surface defects

    Science.gov (United States)

    Xifang, Chen; Wenxia, Zhang; Qianjin, Wang; Jiyang, Fan

    Carbon quantum dots (CQDs) have attracted great attention in the past few years due to their low cytotoxicity, exploited various synthesis methods, unexampled abundance of raw materials on earth, and robust near-infrared to near-UV luminescence. Carbon nanoparticles have applications in biological labeling, delivery of drugs and biological molecules into cells, and light emitting diodes and lasing. CQDs generally exist as nanodiamonds or graphite quantum dots according to previous research reports. In this study, we report the first synthesis of the third-allotrope CQDs through carbonization of sucrose and study their luminescence properties. These CQDs have a body-centered cubic structure and each lattice point is composed of eight atoms which form a sub-cube (so called C8 crystal structure). High-resolution transmission electron microscopy and X-ray diffraction confirm the C8 structure of the synthesized carbon nanocrystallites with an average size of 2 nm. The C8 CQDs exhibit double-band luminescence with two peaks centered at around 432 and 520 nm. The study based on the photoluminescence, UV-Vis absorption, Fourier-transform infrared, and X-ray photoelectron spectroscopies reveals that the green emission originates from the C=O related surface defect.

  1. Polypyrrole and graphene quantum dots @ Prussian Blue hybrid film on graphite felt electrodes: Application for amperometric determination of l-cysteine.

    Science.gov (United States)

    Wang, Lei; Tricard, Simon; Yue, Pengwei; Zhao, Jihua; Fang, Jian; Shen, Weiguo

    2016-03-15

    A novel polypyrrole (PPy) and graphene quantum dots (GQDs) @ Prussian Blue (PB) nanocomposite has been grafted on a graphite felt (GF) substrate (PPy/GQDs@PB/GF), and has been proven to be an efficient electrochemical sensor for the determination of l-cysteine (l-cys). GQDs, which were fabricated by carbonization of citric acid and adsorbed on GF surface ultrasonically, played an important role for promoting the synthesis process of PB via a spontaneous redox reaction between Fe(3+) and [Fe(CN)6](3-). The PPy film has been electro-polymerized to improve the electrochemical stability of the PPy/GQDs@PB/GF electrode. The as-prepared electrode was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), infrared spectroscopy (IR), X-ray diffraction (XRD) and electrochemical methods. It exhibited an excellent activity for the electrocatalytic oxidation of l-cys, with a detection sensitivity equal to 0.41 Amol(-1) L for a concentration range of 0.2-50 μmolL(-1), and equal to 0.15 Amol(-1) L for a concentration range of 50-1000 μmolL(-1). A low detection limit of 0.15 μmolL(-1), as well as a remarkable long-time stability and a negligible sensitivity to interfering analytes, were also ascertained. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. Dermatoscopy of blue vitiligo.

    Science.gov (United States)

    Chandrashekar, L

    2009-07-01

    Blue vitiligo is a distinct variant of vitiligo characterized by a blue-grey appearance of the skin, which corresponds histologically with absence of epidermal melanocytes and presence of numerous dermal melanophages. A 23-year-old woman of Indian origin with Fitzpatrick skin type V presented with a 1-month history of normoaesthetic depigmented macules over the right forearm, dorsa of the hands and right areola. The macule over the right forearm had a bluish tinge. A clinical diagnosis of vitiligo vulgaris with blue vitiligo was made. Dermatoscopy of the interface between the blue macule and the hypopigmented macule revealed a linear depigmented macule in the centre with multiple blue dots and absence of epidermal melanin on the side of the blue macule, and reticular pigmentation with a few depigmented macules and scattered blue dots over the side of the hypopigmented macule. Blue vitiligo was described previously in a patient seropositive for human immunodeficiency virus, and believed to represent postinflammatory hyperpigmentation in areas bordering the vitiliginous patches as a result of psoralen ultraviolet A treatment. This case is unusual because of its rarity and the description of the associated dermatoscopical findings.

  3. Quantum Dots

    Science.gov (United States)

    Tartakovskii, Alexander

    2012-07-01

    Part I. Nanostructure Design and Structural Properties of Epitaxially Grown Quantum Dots and Nanowires: 1. Growth of III/V semiconductor quantum dots C. Schneider, S. Hofling and A. Forchel; 2. Single semiconductor quantum dots in nanowires: growth, optics, and devices M. E. Reimer, N. Akopian, M. Barkelid, G. Bulgarini, R. Heeres, M. Hocevar, B. J. Witek, E. Bakkers and V. Zwiller; 3. Atomic scale analysis of self-assembled quantum dots by cross-sectional scanning tunneling microscopy and atom probe tomography J. G. Keizer and P. M. Koenraad; Part II. Manipulation of Individual Quantum States in Quantum Dots Using Optical Techniques: 4. Studies of the hole spin in self-assembled quantum dots using optical techniques B. D. Gerardot and R. J. Warburton; 5. Resonance fluorescence from a single quantum dot A. N. Vamivakas, C. Matthiesen, Y. Zhao, C.-Y. Lu and M. Atature; 6. Coherent control of quantum dot excitons using ultra-fast optical techniques A. J. Ramsay and A. M. Fox; 7. Optical probing of holes in quantum dot molecules: structure, symmetry, and spin M. F. Doty and J. I. Climente; Part III. Optical Properties of Quantum Dots in Photonic Cavities and Plasmon-Coupled Dots: 8. Deterministic light-matter coupling using single quantum dots P. Senellart; 9. Quantum dots in photonic crystal cavities A. Faraon, D. Englund, I. Fushman, A. Majumdar and J. Vukovic; 10. Photon statistics in quantum dot micropillar emission M. Asmann and M. Bayer; 11. Nanoplasmonics with colloidal quantum dots V. Temnov and U. Woggon; Part IV. Quantum Dot Nano-Laboratory: Magnetic Ions and Nuclear Spins in a Dot: 12. Dynamics and optical control of an individual Mn spin in a quantum dot L. Besombes, C. Le Gall, H. Boukari and H. Mariette; 13. Optical spectroscopy of InAs/GaAs quantum dots doped with a single Mn atom O. Krebs and A. Lemaitre; 14. Nuclear spin effects in quantum dot optics B. Urbaszek, B. Eble, T. Amand and X. Marie; Part V. Electron Transport in Quantum Dots Fabricated by

  4. Quantum dots

    International Nuclear Information System (INIS)

    Kouwenhoven, L.; Marcus, C.

    1998-01-01

    Quantum dots are man-made ''droplets'' of charge that can contain anything from a single electron to a collection of several thousand. Their typical dimensions range from nanometres to a few microns, and their size, shape and interactions can be precisely controlled through the use of advanced nanofabrication technology. The physics of quantum dots shows many parallels with the behaviour of naturally occurring quantum systems in atomic and nuclear physics. Indeed, quantum dots exemplify an important trend in condensed-matter physics in which researchers study man-made objects rather than real atoms or nuclei. As in an atom, the energy levels in a quantum dot become quantized due to the confinement of electrons. With quantum dots, however, an experimentalist can scan through the entire periodic table by simply changing a voltage. In this article the authors describe how quantum dots make it possible to explore new physics in regimes that cannot otherwise be accessed in the laboratory. (UK)

  5. Nearly suppressed photoluminescence blinking of small-sized, blue-green-orange-red emitting single CdSe-based core/gradient alloy shell/shell quantum dots: correlation between truncation time and photoluminescence quantum yield.

    Science.gov (United States)

    Roy, Debjit; Mandal, Saptarshi; De, Chayan K; Kumar, Kaushalendra; Mandal, Prasun K

    2018-04-18

    CdSe-based core/gradient alloy shell/shell semiconductor quantum dots (CGASS QDs) have been shown to be optically quite superior compared to core-shell QDs. However, very little is known about CGASS QDs at the single particle level. Photoluminescence blinking dynamics of four differently emitting (blue (λem = 510), green (λem = 532), orange (λem = 591), and red (λem = 619)) single CGASS QDs having average sizes 600 nm). In this manuscript, we report nearly suppressed PL blinking behaviour of CGASS QDs with average sizes correlation between the event durations and found that residual memory exists in both the ON- and OFF-event durations. Positively correlated successive ON-ON and OFF-OFF event durations and negatively correlated (anti-correlated) ON-OFF event durations perhaps suggest the involvement of more than one type of trapping process within the blinking framework. The timescale corresponding to the additional exponential term has been assigned to hole trapping for ON-event duration statistics. Similarly, for OFF-event duration statistics, this component suggests hole detrapping. We found that the average duration of the exponential process for the ON-event durations is an order of magnitude higher than that of the OFF-event durations. This indicates that the holes are trapped for a significantly long time. When electron trapping is followed by such a hole trapping, long ON-event durations result. We have observed long ON-event durations, as high as 50 s. The competing charge tunnelling model has been used to account for the observed blinking behaviour in these CGASS QDs. Quite interestingly, the PLQY of all of these differently emitting QDs (an ensemble level property) could be correlated with the truncation time (a property at the single particle level). A respective concomitant increase-decrease of ON-OFF event truncation times with increasing PLQY is also indicative of a varying degree of suppression of the Auger recombination processes in these four

  6. Implantação da estratégia DOTS no controle da Tuberculose na Paraíba: entre o compromisso político e o envolvimento das equipes do programa saúde da família (1999-2004 Implementation of the DOTS strategy in the control of TB in Paraiba: between the political commitment and the involvement of the teams of the family health program (1999-2004

    Directory of Open Access Journals (Sweden)

    Lenilde Duarte de Sá

    2011-09-01

    Full Text Available Foi analisada a implantação da estratégia Tratamento Diretamente Observado de Curta Duração (DOTS no controle da tuberculose, sob a ótica dos coordenadores do Programa de Controle da Tuberculose (PCT, nos seis municípios prioritários da Paraíba. Foram realizadas entrevistas semiestruturadas com sete coordenadores de PCT. Fortalezas do DOTS: cinco municípios alcançaram a taxa de cura de 90%. Entre as debilidades identificou-se, na dimensão política, a descontinuidade do cargo de coordenador de PCT, o despreparo da equipe local, a precariedade da estrutura técnico-administrativa e a insuficiência da rede laboratorial; na dimensão operacional ainda é baixa a incorporação da busca de sintomáticos respiratórios pelas Equipes de Saúde da Família. Ocorreram mudanças de cunho epidemiológico, operacional e político. a implantação e garantia da sustentabilidade do DOTS no Estado dependem do modo da organização dos serviços de saúde e o compromisso político do gestor no apoio a estratégia.The scope of this paper is to analyze the implementation of the Directly Observed Treatment Short-Course (DOTS strategy in the control of tuberculosis, from the standpoint of the coordinators of the Tuberculosis Control Program (TCP in six priority municipalities in the state of Paraíba, Brazil. Semi-structured interviews were conducted with seven TCP coordinators. Five municipalities proved to be DOTS success points achieving a 90% cure rate. Among the DOTS weak points in the political dimension, the following aspects were identified: lack of continuity of the TCP coordinator position; lack of preparedness of the local team; precarious technical-administration structure and insufficiency of the laboratory network. In the operational dimension, the search for respiratory symptoms by the Family Health Teams is still low. Changes of an epidemiological, operational and political nature have been incorporated, though the implementation and

  7. Small, pale blue dot' wins photography competition

    Science.gov (United States)

    Banks, Michael

    2018-03-01

    An image of a single positively charged strontium atom held in an ion trap by electric fields has won a UK science photography competition organized by the Engineering and Physical Sciences Research Council (EPSRC).

  8. Evaluation of Code Blue Implementation Outcomes

    Directory of Open Access Journals (Sweden)

    Bengü Özütürk

    2015-09-01

    Full Text Available Aim: In this study, we aimed to emphasize the importance of Code Blue implementation and to determine deficiencies in this regard. Methods: After obtaining the ethics committee approval, 225 patient’s code blue call data between 2012 and 2014 January were retrospectively analyzed. Age and gender of the patients, date and time of the call and the clinics giving Code Blue, the time needed for the Code Blue team to arrive, the rates of false Code Blue calls, reasons for Code Blue calls and patient outcomes were investigated. Results: A total of 225 patients (149 male, 76 female were evaluated in the study. The mean age of the patients was 54.1 years. 142 (67.2% Code Blue calls occurred after hours and by emergency unit. The mean time for the Code Blue team to arrive was 1.10 minutes. Spontaneous circulation was provided in 137 patients (60.8%; 88 (39.1% died. The most commonly identified possible causes were of cardiac origin. Conclusion: This study showed that Code Blue implementation with a professional team within an efficient and targeted time increase the survival rate. Therefore, we conclude that the application of Code Blue carried out by a trained team is an essential standard in hospitals. (The Medical Bulletin of Haseki 2015; 53:204-8

  9. Phosphorene quantum dots

    Science.gov (United States)

    Vishnoi, Pratap; Mazumder, Madhulika; Barua, Manaswee; Pati, Swapan K.; Rao, C. N. R.

    2018-05-01

    Phosphorene, a two-dimensional material, has been a subject of recent investigations. In the present study, we have prepared blue fluorescent phosphorene quantum dots (PQDs) by liquid phase exfoliation of black phosphorus in two non-polar solvents, toluene and mesitylene. The average particle sizes of PQDs decrease from 5.0 to 1.0 nm on increasing the sonicator power from 150 to 225 W. The photoluminescence spectrum of the PQDs is red-shifted in the 395-470 nm range on increasing the excitation-wavelength from 300 to 480 nm. Electron donor and acceptor molecules quench the photoluminescence, with the acceptors showing more marked effects.

  10. The electronic properties of semiconductor quantum dots

    International Nuclear Information System (INIS)

    Barker, J.A.

    2000-10-01

    This work is an investigation into the electronic behaviour of semiconductor quantum dots, particularly self-assembled quantum dot arrays. Processor-efficient models are developed to describe the electronic structure of dots, deriving analytic formulae for the strain tensor, piezoelectric distribution and diffusion- induced evolution of the confinement potential, for dots of arbitrary initial shape and composition profile. These models are then applied to experimental data. Transitions due to individual quantum dots have a narrow linewidth as a result of their discrete density of states. By contrast, quantum dot arrays exhibit inhomogeneous broadening which is generally attributed to size variations between the individual dots in the ensemble. Interpreting the results of double resonance spectroscopy, it is seen that variation in the indium composition of the nominally InAs dots is also present. This result also explains the otherwise confusing relationship between the spread in the ground-state and excited-state transition energies. Careful analysis shows that, in addition to the variations in size and composition, some other as yet unidentified broadening mechanism must also be present. The influence of rapid thermal annealing on dot electronic structure is also considered, finding that the experimentally observed blue-shift and narrowing of the photoluminescence linewidth may both be explained in terms of normal In/Ga interdiffusion. InAs/GaAs self-assembled quantum dots are commonly assumed to have a pyramidal geometry, so that we would expect the energy separation of the ground-state electron and hole levels in the dot to be largest at a positive applied field. This should also be the case for any dot of uniform composition whose shape tapers inwards from base to top, counter to the results of experimental Stark-shift spectroscopy which show a peak transition energy at a negative applied field. It is demonstrated that this inversion of the ground state

  11. The spectrum of dermatoscopic patterns in blue nevi.

    Science.gov (United States)

    Di Cesare, Antonella; Sera, Francesco; Gulia, Andrea; Coletti, Gino; Micantonio, Tamara; Fargnoli, Maria Concetta; Peris, Ketty

    2012-08-01

    Blue nevi are congenital or acquired, dermal dendritic melanocytic proliferations that can simulate melanocytic and nonmelanocytic lesions including melanoma, cutaneous metastasis of melanoma, Spitz/Reed nevi, and basal cell carcinoma. We sought to investigate global and local dermatoscopic patterns of blue nevi compared with melanomas and basal cell carcinomas. We retrospectively analyzed global and local features in 95 dermatoscopic images of blue nevi and in 190 melanomas and basal cell carcinomas that were selected as control lesions on the basis of similar pigmentation. Lesion pigmentation was classified as monochromatic, dichromatic, or multichromatic. A global pattern characterized by homogeneous pigmentation was observed in all of 95 (100%) blue nevi. Eighty of 95 (84.2%) blue nevi presented a homogeneous pattern consisting of one color (blue, black, or brown) or two colors (blue-brown, blue-gray, or blue-black). Fifteen of 95 (15.8%) blue nevi had a multichromatic (blue, gray, black, brown, and/or red) pigmentation. In all, 47 of 95 (49.5%) blue nevi were characterized by pigmentation in the absence of pigment network or any other local dermatoscopic features. And 48 of 95 (50.5%) blue nevi showed local dermatoscopic patterns including whitish scarlike depigmentation, dots/globules, vascular pattern, streaks, and networklike pattern. The study was retrospective and involved only Caucasian people of Italian origin. The characteristic feature of blue nevi is a homogeneous pigmentation that is blue, blue-gray, blue-brown, or blue-black. We showed that a wide spectrum of local dermatoscopic features (whitish scarlike depigmentation, dots/globules, peripheral streaks or vessels) may also be present. In such cases, clinical and dermatoscopic distinction from melanoma or nonmelanocytic lesions may be difficult or impossible, and surgical excision is necessary. Copyright © 2011 American Academy of Dermatology, Inc. Published by Mosby, Inc. All rights reserved.

  12. Blue gods, blue oil, and blue people.

    Science.gov (United States)

    Fairbanks, V F

    1994-09-01

    Studies of the composition of coal tar, which began in Prussia in 1834, profoundly affected the economies of Germany, Great Britain, India, and the rest of the world, as well as medicine and surgery. Such effects include the collapse of the profits of the British indigo monopoly, the growth in economic power of Germany based on coal tar chemistry, and an economic crisis in India that led to more humane tax laws and, ultimately, the independence of India and the end of the British Empire. Additional consequences were the development of antiseptic surgery and the synthesis of a wide variety of useful drugs that have eradicated infections and alleviated pain. Many of these drugs, particularly the commonly used analgesics, sulfonamides, sulfones, and local anesthetics, are derivatives of aniline, originally called "blue oil" or "kyanol." Some of these aniline derivatives, however, have also caused aplastic anemia, agranulocytosis, and methemoglobinemia (that is, "blue people"). Exposure to aniline drugs, particularly when two or three aniline drugs are taken concurrently, seems to be the commonest cause of methemoglobinemia today.

  13. Are real teams healthy teams?

    NARCIS (Netherlands)

    Buljac, M.; van Woerkom, M.; van Wijngaarden, P.

    2013-01-01

    This study examines the impact of real-team--as opposed to a team in name only--characteristics (i.e., team boundaries, stability of membership, and task interdependence) on team processes (i.e., team learning and emotional support) and team effectiveness in the long-term care sector. We employed a

  14. A Single Molecule Investigation of the Photostability of Quantum Dots

    DEFF Research Database (Denmark)

    Christensen, Eva Arnspang; Kulatunga, Pasad; Lagerholm, B. Christoffer

    2012-01-01

    Quantum dots (QDs) are very attractive probes for multi-color fluorescence applications. We report here however that single QDs that are subject to continuous blue excitation from a 100W mercury arc lamp will undergo a continuous blue-switching of the emission wavelength eventually reaching a per...... is especially detrimental for multi-color single molecule applications, as we regularly observe spectral blue-shifts of 50 nm, or more even after only ten seconds of illumination....

  15. Posthuman blues

    CERN Document Server

    Tonnies, Mac

    2013-01-01

    Posthuman Blues, Vol. I is first volume of the edited version of the popular weblog maintained by author Mac Tonnies from 2003 until his tragic death in 2009. Tonnies' blog was a pastiche of his original fiction, reflections on his day-to-day life, trenchant observations of current events, and thoughts on an eclectic range of material he culled from the Internet. What resulted was a remarkably broad portrait of a thoughtful man and the complex times in which he lived, rendered with intellige...

  16. DOT's CAFE rulemaking analysis.

    Science.gov (United States)

    2013-02-13

    Presentation discusses what DOT needs to consider in setting CAFE standards. How DOT's use of the CAFE Compliance and Effects Modeling System helps to analyze potential CAFE Standards. How DOT might approach the next round of CAFE standards for model...

  17. Management Teams

    CERN Document Server

    Belbin, R Meredith Meredith

    2012-01-01

    Meredith Belbin's work on teams has become part of everyday language in organizations all over the world. All kinds of teams and team behaviours are covered. At the end of the book is a self-perception inventory so that readers can match their own personalities to particular team roles. Management Teams is required reading for managers concerned with achieving results by getting the best from their key personnel.

  18. Team Learning Ditinjau dari Team Diversity dan Team Efficacy

    OpenAIRE

    Pohan, Vivi Gusrini Rahmadani; Ancok, Djamaludin

    2010-01-01

    This research attempted to observe team learning from the level of team diversity and team efficacy of work teams. This research used an individual level of analysis rather than the group level. The team members measured the level of team diversity, team efficacy and team learning of the teams through three scales, namely team learning scale, team diversity scale, and team efficacy scale. Respondents in this research were the active team members in a company, PT. Alkindo Mitraraya. The total ...

  19. Team Learning Ditinjau dari Team Diversity dan Team Efficacy

    OpenAIRE

    Vivi Gusrini Rahmadani Pohan; Djamaludin Ancok

    2015-01-01

    This research attempted to observe team learning from the level of team diversity and team efficacy of work teams. This research used an individual level of analysis rather than the group level. The team members measured the level of team diversity, team efficacy and team learning of the teams through three scales, namely team learning scale, team diversity scale, and team efficacy scale. Respondents in this research were the active team members in a company, PT. Alkindo Mitraraya. The total ...

  20. The Blue Marble

    Science.gov (United States)

    2002-01-01

    This spectacular Moderate Resolution Imaging Spectroradiometer (MODIS) 'blue marble' image is based on the most detailed collection of true-color imagery of the entire Earth to date. Using a collection of satellite-based observations, scientists and visualizers stitched together months of observations of the land surface, oceans, sea ice, and clouds into a seamless, true-color mosaic of every square kilometer (.386 square mile) of our planet. Most of the information contained in this image came from MODIS, illustrating MODIS' outstanding capacity to act as an integrated tool for observing a variety of terrestrial, oceanic, and atmospheric features of the Earth. The land and coastal ocean portions of this image is based on surface observations collected from June through September 2001 and combined, or composited, every eight days to compensate for clouds that might block the satellite's view on any single day. Global ocean color (or chlorophyll) data was used to simulate the ocean surface. MODIS doesn't measure 3-D features of the Earth, so the surface observations were draped over topographic data provided by the U.S. Geological Survey EROS Data Center. MODIS observations of polar sea ice were combined with observations of Antarctica made by the National Oceanic and Atmospheric Administration's AVHRR sensor-the Advanced Very High Resolution Radiometer. The cloud image is a composite of two days of MODIS imagery collected in visible light wavelengths and a third day of thermal infra-red imagery over the poles. A large collection of imagery based on the blue marble in a variety of sizes and formats, including animations and the full (1 km) resolution imagery, is available at the Blue Marble page. Image by Reto Stockli, Render by Robert Simmon. Based on data from the MODIS Science Team

  1. Team Sports

    Science.gov (United States)

    ... Games. USA Hockey offers additional information and resources. Softball It's not easy to field full teams of ... an annual tournament sponsored by the National Wheelchair Softball Association , where thirty or so teams show up ...

  2. Quantum-dot-in-perovskite solids

    KAUST Repository

    Ning, Zhijun; Gong, Xiwen; Comin, Riccardo; Walters, Grant; Fan, Fengjia; Voznyy, Oleksandr; Yassitepe, Emre; Buin, Andrei; Hoogland, Sjoerd; Sargent, Edward H.

    2015-01-01

    © 2015 Macmillan Publishers Limited. All rights reserved. Heteroepitaxy - atomically aligned growth of a crystalline film atop a different crystalline substrate - is the basis of electrically driven lasers, multijunction solar cells, and blue-light-emitting diodes. Crystalline coherence is preserved even when atomic identity is modulated, a fact that is the critical enabler of quantum wells, wires, and dots. The interfacial quality achieved as a result of heteroepitaxial growth allows new combinations of materials with complementary properties, which enables the design and realization of functionalities that are not available in the single-phase constituents. Here we show that organohalide perovskites and preformed colloidal quantum dots, combined in the solution phase, produce epitaxially aligned 'dots-in-a-matrix' crystals. Using transmission electron microscopy and electron diffraction, we reveal heterocrystals as large as about 60 nanometres and containing at least 20 mutually aligned dots that inherit the crystalline orientation of the perovskite matrix. The heterocrystals exhibit remarkable optoelectronic properties that are traceable to their atom-scale crystalline coherence: photoelectrons and holes generated in the larger-bandgap perovskites are transferred with 80% efficiency to become excitons in the quantum dot nanocrystals, which exploit the excellent photocarrier diffusion of perovskites to produce bright-light emission from infrared-bandgap quantum-tuned materials. By combining the electrical transport properties of the perovskite matrix with the high radiative efficiency of the quantum dots, we engineer a new platform to advance solution-processed infrared optoelectronics.

  3. Quantum-dot-in-perovskite solids

    KAUST Repository

    Ning, Zhijun

    2015-07-15

    © 2015 Macmillan Publishers Limited. All rights reserved. Heteroepitaxy - atomically aligned growth of a crystalline film atop a different crystalline substrate - is the basis of electrically driven lasers, multijunction solar cells, and blue-light-emitting diodes. Crystalline coherence is preserved even when atomic identity is modulated, a fact that is the critical enabler of quantum wells, wires, and dots. The interfacial quality achieved as a result of heteroepitaxial growth allows new combinations of materials with complementary properties, which enables the design and realization of functionalities that are not available in the single-phase constituents. Here we show that organohalide perovskites and preformed colloidal quantum dots, combined in the solution phase, produce epitaxially aligned \\'dots-in-a-matrix\\' crystals. Using transmission electron microscopy and electron diffraction, we reveal heterocrystals as large as about 60 nanometres and containing at least 20 mutually aligned dots that inherit the crystalline orientation of the perovskite matrix. The heterocrystals exhibit remarkable optoelectronic properties that are traceable to their atom-scale crystalline coherence: photoelectrons and holes generated in the larger-bandgap perovskites are transferred with 80% efficiency to become excitons in the quantum dot nanocrystals, which exploit the excellent photocarrier diffusion of perovskites to produce bright-light emission from infrared-bandgap quantum-tuned materials. By combining the electrical transport properties of the perovskite matrix with the high radiative efficiency of the quantum dots, we engineer a new platform to advance solution-processed infrared optoelectronics.

  4. Influence of ablation wavelength and time on optical properties of laser ablated carbon dots

    Science.gov (United States)

    Isnaeni, Hanna, M. Yusrul; Pambudi, A. A.; Murdaka, F. H.

    2017-01-01

    Carbon dots, which are unique and applicable materials, have been produced using many techniques. In this work, we have fabricated carbon dots made of coconut fiber using laser ablation technique. The purpose of this work is to evaluate two ablation parameters, which are ablation wavelength and ablation time. We used pulsed laser from Nd:YAG laser with emit wavelength at 355 nm, 532 nm and 1064 nm. We varied ablation time one hour and two hours. Photoluminescence and time-resolved photoluminescence setup were used to study the optical properties of fabricated carbon dots. In general, fabricated carbon dots emit bluish green color emission upon excitation by blue laser. We found that carbon dots fabricated using 1064 nm laser produced the highest carbon dots emission among other samples. The peak wavelength of carbon dots emission is between 495 nm until 505 nm, which gives bluish green color emission. Two hours fabricated carbon dots gave four times higher emission than one hour fabricated carbon dot. More emission intensity of carbon dots means more carbon dots nanoparticles were fabricated during laser ablation process. In addition, we also measured electron dynamics of carbon dots using time-resolved photoluminescence. We found that sample with higher emission has longer electron decay time. Our finding gives optimum condition of carbon dots fabrication from coconut fiber using laser ablation technique. Moreover, fabricated carbon dots are non-toxic nanoparticles that can be applied for health, bio-tagging and medical applications.

  5. Teaming up

    DEFF Research Database (Denmark)

    Warhuus, Jan; Günzel-Jensen, Franziska; Robinson, Sarah

    2016-01-01

    types of team formation: random teacher pre-assigned, student selection, and teacher directed diversity. In each of these modules, ethnographic methods (interviews and observations) were employed. Additionally, we had access to students learning logs, formative and summative assessments, and final exams...... functioning entrepreneurial student teams as most teams lack personal chemistry which makes them anchor their work too much in a pre-defined project. In contrast, we find that students that can form their own teams aim for less diverse teams than what is achieved by random assignment. However, the homophily......Questions we care about (Objectives): When students have to work on challenging tasks, as it is often the case in entrepreneurship classrooms that leverage experiential learning, team success becomes central to the students learning. Yet, the formation of teams is often left up to the students...

  6. Gunn's dots in retinal images of 2,286 adolescents

    DEFF Research Database (Denmark)

    Boberg-Ans, Lars C.; Munch, Inger C.; Larsen, Michael

    2017-01-01

    a 6 mm grid centered on the optic disc. Results: One or more Gunn's dots were seen in at least one eye in 82.6% of children. The median number of Gunn's dots per eye was 46 (range 0-482). Most Gunn's dots were found inferior and superior of the optic disc (49.3% and 45.8%, respectively, of the total...... number of Gunn's dots in the population). The odds for having 1 or more Gunn's dots were 3-fold greater in children with dark brown irides compared with children with blue irides (odds ratio 2.99, 95% CI 1.81 to 4.94, P, 0.0001 adjusted for age, sex, retinal nerve fiber layer thickness, refraction...

  7. Teaming up

    DEFF Research Database (Denmark)

    Warhuus, Jan; Günzel-Jensen, Franziska; Robinson, Sarah

    or pre-arranged at random. Therefore we investigate the importance of team formation in the entrepreneurial classroom and ask: (i) What are the underlying factors that influence outcomes of teamwork in student groups? (ii) How does team formation influence student perception of learning?, and (iii) Do...... different team formation strategies produce different teamwork and learning outcomes? Approach: We employed a multiple case study design comprising of 38 student teams to uncover potential links between team formation and student perception of learning. This research draws on data from three different....... A rigorous coding and inductive analysis process was undertaken. Pattern and relationship coding were used to reveal underlying factors, which helped to unveil important similarities and differences between student in different teams’ project progress and perception of learning. Results: When students...

  8. Electroluminescence of colloidal ZnSe quantum dots

    International Nuclear Information System (INIS)

    Dey, S.C.; Nath, S.S.

    2011-01-01

    The article reports a green chemical synthesis of colloidal ZnSe quantum dots at a moderate temperature. The prepared colloid sample is characterised by UV-vis absorption spectroscopy and transmission electron microscopy. UV-vis spectroscopy reveals as-expected blue-shift with strong absorption edge at 400 nm and micrographs show a non-uniform size distribution of ZnSe quantum dots in the range 1-4 nm. Further, photoluminescence and electroluminescence spectroscopies are carried out to study optical emission. Each of the spectroscopies reveals two emission peaks, indicating band-to-band transition and defect related transition. From the luminescence studies, it can be inferred that the recombination of electrons and holes resulting from interband transition causes violet emission and the recombination of a photon generated hole with a charged state of Zn-vacancy gives blue emission. Meanwhile electroluminescence study suggests the application of ZnSe quantum dots as an efficient light emitting device with the advantage of colour tuning (violet-blue-violet). - Highlights: → Synthesis of ZnSe quantum dots by a green chemical route. → Characterisation: UV-vis absorption spectroscopy and transmission electron microscopy. → Analysis of UV-vis absorption spectrum and transmission electron micrographs. → Study of electro-optical properties by photoluminescence and electroluminescence. → Conclusion: ZnSe quantum dots can be used as LED with dual colour emission.

  9. Blue-Green Algae

    Science.gov (United States)

    ... that taking a specific blue-green algae product (Super Blue-Green Algae, Cell Tech, Klamath Falls, OR) ... system. Premenstrual syndrome (PMS). Depression. Digestion. Heart disease. Memory. Wound healing. Other conditions. More evidence is needed ...

  10. Virtual Teams.

    Science.gov (United States)

    Geber, Beverly

    1995-01-01

    Virtual work teams scattered around the globe are becoming a feature of corporate workplaces. Although most people prefer face-to-face meetings and interactions, reality often requires telecommuting. (JOW)

  11. [Analysis on workload for hospital DOTS service].

    Science.gov (United States)

    Nagata, Yoko; Urakawa, Minako; Kobayashi, Noriko; Kato, Seiya

    2014-04-01

    , ward clerks, head nurses, and doctors were 100, 90, 87, 86, and 63 min, respectively. For other professions, including medical social workers, nursing aids, nutritionists, and physical therapists, the working times for each activity of the DOTS service were 31, 18, 10, and 8 min, respectively. The professionals who spent a longer time on health education, support for patient adherence, and coordination with the health center were pharmacists, doctors, and head nurses; nurses, pharmacists, and doctors; and head nurses, doctors, and ward clerks, respectively. Aging of tuberculosis patients was associated with problems on adherence in many patients, including patients who were not suited for a standard regimen, patients whose activity of daily life had deteriorated due to senile dementia, patients with diabetes mellitus, etc. Smoking cessation and mental care for cases of multi-drug resistant disease are new challenges in tuberculosis patient care. The present study clearly indicated that activities including patient education, support for patient adherence, and coordination with the health center--essential components of the hospital DOTS service according to the Japanese DOTS Strategy--were performed by a team of professionals including doctors, nurses, pharmacists, medical social workers, etc., depending on the features and roles that they serve and the needs of each patient. For good practice of hospital DOTS, it is essential to not only provide DOTS, but also effectively provide individual or group health education and coordinate with health centers, thus aiming towards a better community DOTS service after patient discharge.

  12. Nonlinear Dot Plots.

    Science.gov (United States)

    Rodrigues, Nils; Weiskopf, Daniel

    2018-01-01

    Conventional dot plots use a constant dot size and are typically applied to show the frequency distribution of small data sets. Unfortunately, they are not designed for a high dynamic range of frequencies. We address this problem by introducing nonlinear dot plots. Adopting the idea of nonlinear scaling from logarithmic bar charts, our plots allow for dots of varying size so that columns with a large number of samples are reduced in height. For the construction of these diagrams, we introduce an efficient two-way sweep algorithm that leads to a dense and symmetrical layout. We compensate aliasing artifacts at high dot densities by a specifically designed low-pass filtering method. Examples of nonlinear dot plots are compared to conventional dot plots as well as linear and logarithmic histograms. Finally, we include feedback from an expert review.

  13. Fabrication and optical properties of type-II InP/InAs nanowire/quantum-dot heterostructures

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Xin; Zhang, Xia; Li, Junshuai; Wu, Yao; Li, Bang; Ren, Xiaomin [State Key Laboratory of Information Photonics and Optical Communications, Beijing University of Posts and Telecommunications, Beijing, 100876 (China)

    2016-02-15

    The growth and optical properties of InAs quantum dots on a pure zinc blende InP nanowire are investigated. The quantum dots are formed in Stranski-Krastanov mode and exhibit pure zinc blende crystal structure. A substantial blueshift of the dots peak with a cube-root dependence on the excitation power is observed, suggesting a type-II band alignment. The peak position of dots initially red-shifts and then blue-shifts with increasing temperature, which is attributed to the carrier redistribution among the quantum dots. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  14. The influence of bio-conjugation on photoluminescence of CdSe/ZnS quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Torchynska, Tetyana V. [ESFM Instituto Politécnico Nacional, Av. Instituto Politécnico Nacional, México, D.F. 07738 (Mexico); Vorobiev, Yuri V. [Centro de Investigación y de Estudios Avanzados del IPN (CINVESTAV) Querétaro, Libramiento Norponiente 2000, Fracc. Real de Juriquilla, 76230 Querétaro (Mexico); Makhniy, Victor P. [Yuri Fedkovych Chernivtsi National University, 2 Kotsyubynsky Str., 58012 Chernivtsi (Ukraine); Horley, Paul P., E-mail: paul.horley@cimav.edu.mx [Centro de Investigación en Materiales Avanzados, S.C. (CIMAV), Chihuahua/Monterrey, 120 Avenida Miguel de Cervantes, 31109 Chihuahua (Mexico)

    2014-11-15

    We report a considerable blue shift in the luminescence spectra of CdSe/ZnS quantum dots conjugated to anti-interleukin-10 antibodies. This phenomenon can be explained theoretically by accounting for bio-conjugation as a process causing electrostatic interaction between a quantum dot and an antibody, which reduces effective volume of the dot core. To solve the Schrödinger equation for an exciton confined in the quantum dot, we use mirror boundary conditions that were successfully tested for different geometries of quantum wells.

  15. Better to be red than blue in virtual competition

    DEFF Research Database (Denmark)

    Ilie, Andrei; Ioan, Silvia; Zagrean, Leon

    2008-01-01

    In the 2004 Olympic Games, opponents wearing red athletic uniforms were more likely to win against opponents wearing blue uniforms. To investigate whether this color bias extends to the world of virtual competition, we compared the performance of red and blue teams in a popular multiplayer first......-person-shooter (FPS) computer game. For 3 consecutive months, we collected data from a publicly available global statistics server. Outcomes from 1,347 matches played by the top 10 players on the same virtual arena were included. Red teams won 54.9% of matches, and this effect was highly significant. Our data suggest...... that joining the red team may offer a slight advantage over the blue team in virtual competition, and this should be accounted for when designing FPS games. It is likely that "seeing red" may trigger a powerful psychological distractor signal in human aggressive competition that can affect the outcome...

  16. From DOT to Dotty

    CERN Multimedia

    CERN. Geneva

    2017-01-01

    - Module types are interfaces, which can be abstracted. In this talk Martin will present DOT, a particularly simple calculus that can express systems following these principles. DOT has been developed as the foundation of the next version of Scala. He will also report on dotty, a new Scala compiler that implements the constructs of DOT in its core data structures and that uses the lessons learned to drive Scala’s evolution.

  17. Team Learning and Team Composition in Nursing

    Science.gov (United States)

    Timmermans, Olaf; Van Linge, Roland; Van Petegem, Peter; Elseviers, Monique; Denekens, Joke

    2011-01-01

    Purpose: This study aims to explore team learning activities in nursing teams and to test the effect of team composition on team learning to extend conceptually an initial model of team learning and to examine empirically a new model of ambidextrous team learning in nursing. Design/methodology/approach: Quantitative research utilising exploratory…

  18. DIFFERENT DIMENSIONS OF TEAMS

    OpenAIRE

    Goparaju Purna SUDHAKAR

    2013-01-01

    Popularity of teams is growing in 21st Century. Organizations are getting their work done through different types of teams. Teams have proved that the collective performance is more than the sum of the individual performances. Thus, the teams have got different dimensions such as quantitative dimensions and qualitative dimensions. The Quantitative dimensions of teams such as team performance, team productivity, team innovation, team effectiveness, team efficiency, team decision making and tea...

  19. TEAM ORGANISERING

    DEFF Research Database (Denmark)

    Levisen, Vinie; Haugaard, Lena

    2004-01-01

    organisation som denne? Når teams i samtiden anses for at være en organisationsform, der fremmer organisatorisk læring, beror det på, at teamet antages at udgøre et ikke-hierarkisk arbejdsfællesskab, hvor erfaringer udveksles og problemer løses. Teamorganisering kan imidlertid udformes på mange forskellige...

  20. Transport in quantum dots

    International Nuclear Information System (INIS)

    Deus, Fernanda; Continetino, Mucio

    2011-01-01

    Full text. In this work we study the time dependent transport in interacting quantum dot. This is a zero-dimensional nano structure system which has quantized electronic states. In our purpose, we are interested in studying such system in a Coulomb blockade regime where a mean-field treatment of the electronic correlations are appropriate. The quantum dot is described by an Anderson type of Hamiltonian where the hybridization term arises from the contact with the leads. We consider a time dependence of both the energy of the localized state in the quantum dot and of the hybridization-like term. These time dependent parameters, under certain conditions, induce a current in the quantum dot even in the absence of difference on the chemical potential of the leads. The approach to this non-equilibrium problem requires the use of a Keldysh formalism. We calculate the non- equilibrium Green's functions and obtain results for the average (equilibrium term) and the non-equilibrium values of the electronic occupation number in the dot. we consider the possibility of a magnetic solution, with different values for the average up and down spins in the quantum dot. Our results allow to obtain, for instance, the tunneling current through the dot. The magnetic nature of the dot, for a certain range of parameters should give rise also to an induced spin current through the dot

  1. Blue Emission in Proteins

    OpenAIRE

    Sarkar, Sohini; Sengupta, Abhigyan; Hazra, Partha; Mandal, Pankaj

    2014-01-01

    Recent literatures reported blue-green emission from amyloid fibril as exclusive signature of fibril formation. This unusual visible luminescence is regularly used to monitor fibril growth. Blue-green emission has also been observed in crystalline protein and in solution. However, the origin of this emission is not known exactly. Our spectroscopic study of serum proteins reveals that the blue-green emission is a property of protein monomer. Evidences suggest that semiconductor-like band struc...

  2. Blue and green luminescence of reduced graphene oxide quantum dots

    Czech Academy of Sciences Publication Activity Database

    Štengl, Václav; Bakardjieva, Snejana; Henych, Jiří; Lang, Kamil; Kormunda, M.

    2013-01-01

    Roč. 63, november (2013), s. 537-546 ISSN 0008-6223 Institutional support: RVO:61388980 Keywords : different solvents * graphene oxides * green luminescence * intensive cavitations * N-methyl-2-pyrrolidone Subject RIV: CA - Inorganic Chemistry Impact factor: 6.160, year: 2013

  3. Quantum Dots: Theory

    Energy Technology Data Exchange (ETDEWEB)

    Vukmirovic, Nenad; Wang, Lin-Wang

    2009-11-10

    This review covers the description of the methodologies typically used for the calculation of the electronic structure of self-assembled and colloidal quantum dots. These are illustrated by the results of their application to a selected set of physical effects in quantum dots.

  4. Quantum dot spectroscopy

    DEFF Research Database (Denmark)

    Leosson, Kristjan

    1999-01-01

    Semiconductor quantum dots ("solid state atoms") are promising candidates for quantum computers and future electronic and optoelectronic devices. Quantum dots are zero-dimensional electronic systems and therefore have discrete energy levels, similar to atoms or molecules. The size distribution of...

  5. Quantum dot spectroscopy

    DEFF Research Database (Denmark)

    Leosson, Kristjan

    Semiconductor quantum dots ("solid-state atoms") are promising candidates for quantum computers and future electronic and optoelectronic devices. Quantum dots are zero-dimensional electronic systems and therefore have discrete energy levels, similar to atoms or molecules. The size distribution of...

  6. Synthesis of quantum dots

    Science.gov (United States)

    McDaniel, Hunter

    2017-10-17

    Common approaches to synthesizing alloyed quantum dots employ high-cost, air-sensitive phosphine complexes as the selenium precursor. Disclosed quantum dot synthesis embodiments avoid these hazardous and air-sensitive selenium precursors. Certain embodiments utilize a combination comprising a thiol and an amine that together reduce and complex the elemental selenium to form a highly reactive selenium precursor at room temperature. The same combination of thiol and amine acts as the reaction solvent, stabilizing ligand, and sulfur source in the synthesis of quantum dot cores. A non-injection approach may also be used. The optical properties of the quantum dots synthesized by this new approach can be finely tuned for a variety of applications by controlling size and/or composition of size and composition. Further, using the same approach, a shell can be grown around a quantum dot core that improves stability, luminescence efficiency, and may reduce toxicity.

  7. Blue Ocean Thinking

    Science.gov (United States)

    Orem, Donna

    2016-01-01

    This article describes a concept called the "blue ocean thinking strategy," developed by W. Chan Kim and Renée Mauborgne, professors at INSEAD, an international graduate school of business in France. The "blue ocean" thinking strategy considers opportunities to create new markets for services, rather than focusing solely on…

  8. Synthesis of highly fluorescent hydrophobic carbon dots by hot injection method using Paraplast as precursor

    International Nuclear Information System (INIS)

    Talib, Abou; Pandey, Sunil; Thakur, Mukeshchand; Wu, Hui-Fen

    2015-01-01

    We have reported synthesis of bright blue colored hydrophobic carbon dots (hC-dots) using highly pure blend of polymers called Paraplast. We developed a hot injection method for making nearly monodispersed hC-dots with a diameter in a range: 5–30 nm as confirmed by high resolution transmission electron microscopy (HRTEM). The involvement of various functional groups was confirmed by Fourier transform infra-red (FTIR) spectroscopy. These hC-dots were incubated with breast cancer stem cells in order to check the entry as well as biological imaging. The cells were analyzed using epifluorescent microscopy. hC-dots showed concentration dependent cytotoxicity (LD 50 : 50 mg/ml) and could be used for bioimaging even at lower concentration (0.5 mg/ml). hC-dots were found to be versatile agents for peeping inside the cells which could also be used for delivery of water insoluble chemotherapeutic agents to variety of solid tumors. - Highlights: • Synthesis of hydrophobic carbon dots from polymer based Paraplast • Deep blue color under the influence of UV light • Typical optical properties used for biological imaging • Biological imaging of breast cancer stem cells revealing potential of carbon dots

  9. Synthesis of highly fluorescent hydrophobic carbon dots by hot injection method using Paraplast as precursor

    Energy Technology Data Exchange (ETDEWEB)

    Talib, Abou [Doctoral Degree Program in Marine Biotechnology, National Sun Yat-Sen University, Kaohsiung 80424, Taiwan (China); Pandey, Sunil [Department of Chemistry, National Sun Yat-Sen University, 70, Lien-Hai Road, Kaohsiung 80424, Taiwan (China); Center for Nanoscience and Nanotechnology, National Sun Yat-Sen University, 70, Lien-Hai Road, Kaohsiung 80424, Taiwan (China); Thakur, Mukeshchand [Department of Chemistry, National Sun Yat-Sen University, 70, Lien-Hai Road, Kaohsiung 80424, Taiwan (China); Wu, Hui-Fen, E-mail: hui@faculty.nsysu.edu.tw [Department of Chemistry, National Sun Yat-Sen University, 70, Lien-Hai Road, Kaohsiung 80424, Taiwan (China); Center for Nanoscience and Nanotechnology, National Sun Yat-Sen University, 70, Lien-Hai Road, Kaohsiung 80424, Taiwan (China); Doctoral Degree Program in Marine Biotechnology, National Sun Yat-Sen University, Kaohsiung 80424, Taiwan (China); School of Pharmacy, College of Pharmacy, Kaohsiung Medical University, Kaohsiung 800, Taiwan (China); Institute of Medical Science and Technology, National Sun Yat-Sen University, Kaohsiung, 80424, Taiwan (China)

    2015-03-01

    We have reported synthesis of bright blue colored hydrophobic carbon dots (hC-dots) using highly pure blend of polymers called Paraplast. We developed a hot injection method for making nearly monodispersed hC-dots with a diameter in a range: 5–30 nm as confirmed by high resolution transmission electron microscopy (HRTEM). The involvement of various functional groups was confirmed by Fourier transform infra-red (FTIR) spectroscopy. These hC-dots were incubated with breast cancer stem cells in order to check the entry as well as biological imaging. The cells were analyzed using epifluorescent microscopy. hC-dots showed concentration dependent cytotoxicity (LD{sub 50}: 50 mg/ml) and could be used for bioimaging even at lower concentration (0.5 mg/ml). hC-dots were found to be versatile agents for peeping inside the cells which could also be used for delivery of water insoluble chemotherapeutic agents to variety of solid tumors. - Highlights: • Synthesis of hydrophobic carbon dots from polymer based Paraplast • Deep blue color under the influence of UV light • Typical optical properties used for biological imaging • Biological imaging of breast cancer stem cells revealing potential of carbon dots.

  10. Photoluminescence of patterned CdSe quantum dot for anti-counterfeiting label on paper

    International Nuclear Information System (INIS)

    Isnaeni,; Yulianto, Nursidik; Suliyanti, Maria Margaretha

    2016-01-01

    We successfully developed a method utilizing colloidal CdSe nanocrystalline quantum dot for anti-counterfeiting label on a piece of glossy paper. We deposited numbers and lines patterns of toluene soluble CdSe quantum dot using rubber stamper on a glossy paper. The width of line pattern was about 1-2 mm with 1-2 mm separation between lines. It required less than one minute for deposited CdSe quantum dot on glossy paper to dry and become invisible by naked eyes. However, patterned quantum dot become visible using long-pass filter glasses upon excitation of UV lamp or blue laser. We characterized photoluminescence of line patterns of quantum dot, and we found that emission boundaries of line patterns were clearly observed. The error of line size and shape were mainly due to defect of the original stamper. The emission peak wavelength of CdSe quantum dot was 629 nm. The emission spectrum of deposited quantum dot has full width at half maximum (FWHM) of 30-40 nm. The spectra similarity between deposited quantum dot and the original quantum dot in solution proved that our stamping method can be simply applied on glossy paper without changing basic optical property of the quantum dot. Further development of this technique is potential for anti-counterfeiting label on very important documents or objects.

  11. Photoluminescence of patterned CdSe quantum dot for anti-counterfeiting label on paper

    Energy Technology Data Exchange (ETDEWEB)

    Isnaeni,, E-mail: isnaeni@lipi.go.id; Yulianto, Nursidik; Suliyanti, Maria Margaretha [Research Center for Physics, Indonesian Institute of Sciences, Building 442, Kawasan Puspiptek, South Tangerang,Banten 15314 Indonesia (Indonesia)

    2016-03-11

    We successfully developed a method utilizing colloidal CdSe nanocrystalline quantum dot for anti-counterfeiting label on a piece of glossy paper. We deposited numbers and lines patterns of toluene soluble CdSe quantum dot using rubber stamper on a glossy paper. The width of line pattern was about 1-2 mm with 1-2 mm separation between lines. It required less than one minute for deposited CdSe quantum dot on glossy paper to dry and become invisible by naked eyes. However, patterned quantum dot become visible using long-pass filter glasses upon excitation of UV lamp or blue laser. We characterized photoluminescence of line patterns of quantum dot, and we found that emission boundaries of line patterns were clearly observed. The error of line size and shape were mainly due to defect of the original stamper. The emission peak wavelength of CdSe quantum dot was 629 nm. The emission spectrum of deposited quantum dot has full width at half maximum (FWHM) of 30-40 nm. The spectra similarity between deposited quantum dot and the original quantum dot in solution proved that our stamping method can be simply applied on glossy paper without changing basic optical property of the quantum dot. Further development of this technique is potential for anti-counterfeiting label on very important documents or objects.

  12. Asteroid team

    International Nuclear Information System (INIS)

    Matson, D.L.

    1988-01-01

    The purpose of this task is to support asteroid research and the operation of an Asteroid Team within the Earth and Space Sciences Division at the Jet Propulsion Laboratory (JPL). The Asteroid Team carries out original research on asteroids in order to discover, better characterize and define asteroid properties. This information is needed for the planning and design of NASA asteroid flyby and rendezvous missions. The asteroid Team also provides scientific and technical advice to NASA and JPL on asteroid related programs. Work on asteroid classification continued and the discovery of two Earth-approaching M asteroids was published. In the asteroid photometry program researchers obtained N or Q photometry for more than 50 asteroids, including the two M-earth-crossers. Compositional analysis of infrared spectra (0.8 to 2.6 micrometer) of asteroids is continuing. Over the next year the work on asteroid classification and composition will continue with the analysis of the 60 reduced infrared spectra which we now have at hand. The radiometry program will continue with the reduction of the N and Q bandpass data for the 57 asteroids in order to obtain albedos and diameters. This year the emphasis will shift to IRAS follow-up observations; which includes objects not observed by IRAS and objects with poor or peculiar IRAS data. As in previous year, we plan to give top priority to any opportunities for observing near-Earth asteroids and the support (through radiometric lightcurve observations from the IRTF) of any stellar occultations by asteroids for which occultation observation expeditions are fielded. Support of preparing of IRAS data for publication and of D. Matson for his participation in the NASA Planetary Astronomy Management and Operations Working Group will continue

  13. Asteroid team

    Science.gov (United States)

    Matson, D. L.

    1988-01-01

    The purpose of this task is to support asteroid research and the operation of an Asteroid Team within the Earth and Space Sciences Division at the Jet Propulsion Laboratory (JPL). The Asteroid Team carries out original research on asteroids in order to discover, better characterize and define asteroid properties. This information is needed for the planning and design of NASA asteroid flyby and rendezvous missions. The asteroid Team also provides scientific and technical advice to NASA and JPL on asteroid related programs. Work on asteroid classification continued and the discovery of two Earth-approaching M asteroids was published. In the asteroid photometry program researchers obtained N or Q photometry for more than 50 asteroids, including the two M-earth-crossers. Compositional analysis of infrared spectra (0.8 to 2.6 micrometer) of asteroids is continuing. Over the next year the work on asteroid classification and composition will continue with the analysis of the 60 reduced infrared spectra which we now have at hand. The radiometry program will continue with the reduction of the N and Q bandpass data for the 57 asteroids in order to obtain albedos and diameters. This year the emphasis will shift to IRAS follow-up observations; which includes objects not observed by IRAS and objects with poor or peculiar IRAS data. As in previous year, we plan to give top priority to any opportunities for observing near-Earth asteroids and the support (through radiometric lightcurve observations from the IRTF) of any stellar occultations by asteroids for which occultation observation expeditions are fielded. Support of preparing of IRAS data for publication and of D. Matson for his participation in the NASA Planetary Astronomy Management and Operations Working Group will continue.

  14. Featured Image: Bright Dots in a Sunspot

    Science.gov (United States)

    Kohler, Susanna

    2018-03-01

    This image of a sunspot, located in in NOAA AR 12227, was captured in December 2014 by the 0.5-meter Solar Optical Telescope on board the Hinode spacecraft. This image was processed by a team of scientists led by Rahul Yadav (Udaipur Solar Observatory, Physical Research Laboratory Dewali, India) in order to examine the properties of umbral dots: transient, bright features observed in the umbral region (the central, darkest part) of a sunspot. By exploring these dots, Yadav and collaborators learned how their properties relate to the large-scale properties of the sunspots in which they form for instance, how do the number, intensities, or filling factors of dots relate to the size of a sunspots umbra? To find out more about the authors results, check out the article below.Sunspot in NOAA AR 11921. Left: umbralpenumbral boundary. Center: the isolated umbra from the sunspot. Right: The umbra with locations of umbral dots indicated by yellow plus signs. [Adapted from Yadav et al. 2018]CitationRahul Yadav et al 2018 ApJ 855 8. doi:10.3847/1538-4357/aaaeba

  15. Team designing

    DEFF Research Database (Denmark)

    Denise J. Stokholm, Marianne

    2012-01-01

    Future wellbeing is depending on human competences in order to strengthen a sustainable development. This requires system thinking and ability to deal with complexity, dynamic and a vast of information. `We need to move away from present principles of breaking down problems into components and gi...... thinking and communication in design. Trying to answer the question: How can visual system models facilitate learning in design thinking and team designing?......Future wellbeing is depending on human competences in order to strengthen a sustainable development. This requires system thinking and ability to deal with complexity, dynamic and a vast of information. `We need to move away from present principles of breaking down problems into components and give...... in relation to a design-engineering education at Aalborg University. It will exemplify how the model has been used in workshops on team designing, challenged design learning and affected design competence. In specific it will investigate the influence of visual models of the perception of design, design...

  16. Highly Efficient Perovskite-Quantum-Dot Light-Emitting Diodes by Surface Engineering

    KAUST Repository

    Pan, Jun; Quan, Li Na; Zhao, Yongbiao; Peng, Wei; Banavoth, Murali; Sarmah, Smritakshi P.; Yuan, Mingjian; Sinatra, Lutfan; AlYami, Noktan; Liu, Jiakai; Yassitepe, Emre; Yang, Zhenyu; Voznyy, Oleksandr; Comin, Riccardo; Hedhili, Mohamed N.; Mohammed, Omar F.; Lu, Zheng Hong; Kim, Dong Ha; Sargent, Edward H.; Bakr, Osman

    2016-01-01

    A two-step ligand-exchange strategy is developed, in which the long-carbon-chain ligands on all-inorganic perovskite (CsPbX3, X = Br, Cl) quantum dots (QDs) are replaced with halide-ion-pair ligands. Green and blue light-emitting diodes made from the halide-ion-paircapped quantum dots exhibit high external quantum efficiencies compared with the untreated QDs.

  17. GaN quantum dots: from basic understanding to unique applications

    International Nuclear Information System (INIS)

    Pelekanos, N T; Dialynas, G E; Simon, J; Mariette, H; Daudin, B

    2005-01-01

    The GaN self-assembled quantum dots constitute a very special and intriguing type of semiconductor nanostructure, mainly because they carry in their structure a giant internal electric field that can reach a value up to 7 MV/cm. In this report, we review the most important structural and optical properties of GaN quantum dots, and we discuss their advantages and limitations for blue-UV optoelectronic applications. (invited paper)

  18. Highly Efficient Perovskite-Quantum-Dot Light-Emitting Diodes by Surface Engineering

    KAUST Repository

    Pan, Jun

    2016-08-16

    A two-step ligand-exchange strategy is developed, in which the long-carbon-chain ligands on all-inorganic perovskite (CsPbX3, X = Br, Cl) quantum dots (QDs) are replaced with halide-ion-pair ligands. Green and blue light-emitting diodes made from the halide-ion-paircapped quantum dots exhibit high external quantum efficiencies compared with the untreated QDs.

  19. Two optically active molybdenum disulfide quantum dots as tetracycline sensors

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Zhuosen; Lin, Jintai [School of Chemistry and Environment, South China Normal University, Guangzhou 510006 (China); Gao, Jinwei [Institute for Advanced Materials, Academy of Advanced Optoelectronics, South China Normal University, Guangzhou 510006 (China); Wang, Qianming, E-mail: qmwang@scnu.edu.cn [Key Laboratory of Theoretical Chemistry of Environment, Ministry of Education, School of Chemistry and Environment, South China Normal University, Guangzhou 510006 (China); School of Chemistry and Environment, South China Normal University, Guangzhou 510006 (China); Guangzhou Key Laboratory of Materials for Energy Conversion and Storage, 510006 (China)

    2016-08-01

    In this work, we use the hydrothermal method to develop two luminescent MoS{sub 2} quantum dots (QDs) from L-cysteine and glutathione as sulfur precursors. The special blue emissions give rise to an instantaneous determination of tetracycline (TC) through the quenching of its luminescence. The accessibility of the optical materials and recognition mechanism have been extensively studied. This strategy demonstrated that MoS{sub 2} could act as a new platform for anchoring bioactive species or particular functional moieties. - Highlights: • MoS{sub 2} nanostructures with water solubility have been fabricated. • Blue emission has been achieved. • It displays selective detection to tetracyclines in water.

  20. Blue ocean strategy.

    Science.gov (United States)

    Kim, W Chan; Mauborgne, Renée

    2004-10-01

    Despite a long-term decline in the circus industry, Cirque du Soleil profitably increased revenue 22-fold over the last ten years by reinventing the circus. Rather than competing within the confines of the existing industry or trying to steal customers from rivals, Cirque developed uncontested market space that made the competition irrelevant. Cirque created what the authors call a blue ocean, a previously unknown market space. In blue oceans, demand is created rather than fought over. There is ample opportunity for growth that is both profitable and rapid. In red oceans--that is, in all the industries already existing--companies compete by grabbing for a greater share of limited demand. As the market space gets more crowded, prospects for profits and growth decline. Products turn into commodities, and increasing competition turns the water bloody. There are two ways to create blue oceans. One is to launch completely new industries, as eBay did with online auctions. But it's much more common for a blue ocean to be created from within a red ocean when a company expands the boundaries of an existing industry. In studying more than 150 blue ocean creations in over 30 industries, the authors observed that the traditional units of strategic analysis--company and industry--are of limited use in explaining how and why blue oceans are created. The most appropriate unit of analysis is the strategic move, the set of managerial actions and decisions involved in making a major market-creating business offering. Creating blue oceans builds brands. So powerful is blue ocean strategy, in fact, that a blue ocean strategic move can create brand equity that lasts for decades.

  1. Quantum dot molecules

    CERN Document Server

    Wu, Jiang

    2014-01-01

    This book reviews recent advances in the exciting and rapidly growing field of quantum dot molecules (QDMs). It offers state-of-the-art coverage of novel techniques and connects fundamental physical properties with device design.

  2. Travelling with football teams

    African Journals Online (AJOL)

    ultimately on the performance of the teams on the playing field and not so much ... However, travelling with a football team presents the team physician .... physician to determine the nutritional ..... diarrhoea in elite athletes: an audit of one team.

  3. Blue Ribbon Panel Report

    Science.gov (United States)

    An NCI Cancer Currents blog by the NCI acting director thanking the cancer community for contributing to the Cancer Moonshot Blue Ribbon Panel report, which was presented to the National Cancer Advisory Board on September 7.

  4. Northeast Atlantic blue whiting

    OpenAIRE

    Heino, Mikko

    2010-01-01

    Heino, M. 2010. Northeast Atlantic blue whiting. In Life cycle spatial patterns of small pelagic fish in the Northeast Atlantic, pp. 59-64. Ed by P. Petitgas. ICES Cooperative Research Report 306. ICES, Copenhagen.

  5. New York Blue

    Data.gov (United States)

    Federal Laboratory Consortium — New York Blue is used cooperatively by the Laboratory and Stony Brook University as part of the New York Center for Computation Sciences. Ranked as the 28th fastest...

  6. Study on team evaluation. Team process model for team evaluation

    International Nuclear Information System (INIS)

    Sasou Kunihide; Ebisu, Mitsuhiro; Hirose, Ayako

    2004-01-01

    Several studies have been done to evaluate or improve team performance in nuclear and aviation industries. Crew resource management is the typical example. In addition, team evaluation recently gathers interests in other teams of lawyers, medical staff, accountants, psychiatrics, executive, etc. However, the most evaluation methods focus on the results of team behavior that can be observed through training or actual business situations. What is expected team is not only resolving problems but also training younger members being destined to lead the next generation. Therefore, the authors set the final goal of this study establishing a series of methods to evaluate and improve teams inclusively such as decision making, motivation, staffing, etc. As the first step, this study develops team process model describing viewpoints for the evaluation. The team process is defined as some kinds of power that activate or inactivate competency of individuals that is the components of team's competency. To find the team process, the authors discussed the merits of team behavior with the experienced training instructors and shift supervisors of nuclear/thermal power plants. The discussion finds four team merits and many components to realize those team merits. Classifying those components into eight groups of team processes such as 'Orientation', 'Decision Making', 'Power and Responsibility', 'Workload Management', 'Professional Trust', 'Motivation', 'Training' and 'staffing', the authors propose Team Process Model with two to four sub processes in each team process. In the future, the authors will develop methods to evaluate some of the team processes for nuclear/thermal power plant operation teams. (author)

  7. Graphene quantum dots

    CERN Document Server

    Güçlü, Alev Devrim; Korkusinski, Marek; Hawrylak, Pawel

    2014-01-01

    This book reflects the current status of theoretical and experimental research of graphene based nanostructures, in particular quantum dots, at a level accessible to young researchers, graduate students, experimentalists and theorists. It presents the current state of research of graphene quantum dots, a single or few monolayer thick islands of graphene. It introduces the reader to the electronic and optical properties of graphite, intercalated graphite and graphene, including Dirac fermions, Berry's phase associated with sublattices and valley degeneracy, covers single particle properties of

  8. Rainbow Emission from an Atomic Transition in Doped Quantum Dots.

    Science.gov (United States)

    Hazarika, Abhijit; Pandey, Anshu; Sarma, D D

    2014-07-03

    Although semiconductor quantum dots are promising materials for displays and lighting due to their tunable emissions, these materials also suffer from the serious disadvantage of self-absorption of emitted light. The reabsorption of emitted light is a serious loss mechanism in practical situations because most phosphors exhibit subunity quantum yields. Manganese-based phosphors that also exhibit high stability and quantum efficiency do not suffer from this problem but in turn lack emission tunability, seriously affecting their practical utility. Here, we present a class of manganese-doped quantum dot materials, where strain is used to tune the wavelength of the dopant emission, extending the otherwise limited emission tunability over the yellow-orange range for manganese ions to almost the entire visible spectrum covering all colors from blue to red. These new materials thus combine the advantages of both quantum dots and conventional doped phosphors, thereby opening new possibilities for a wide range of applications in the future.

  9. Team responsibility structure and team performance

    NARCIS (Netherlands)

    Doorewaard, J.A.C.M.; Hootegem, G. van; Huys, R.

    2002-01-01

    The purpose is to analyse the impact of team responsibility (the division of job regulation tasks between team leader and team members) on team performance. It bases an analysis on 36 case studies in The Netherlands which are known to have implemented team‐based work. The case studies were executed

  10. Synthesis, characterization and cells and tissues imaging of carbon quantum dots

    Science.gov (United States)

    Wang, Jing; Li, Qilong; Zhou, JingE.; Wang, Yiting; Yu, Lei; Peng, Hui; Zhu, Jianzhong

    2017-10-01

    Compare to other quantum dots, carbon quantum dots have its own incomparable advantages, such as low cell toxicity, favorable biocompatibility, cheap production cost, mild reaction conditions, easy to large-scale synthesis and functionalization. In this thesis, we took citric acid monohydrate and diethylene glycol bis (3-aMinopropyl) ether as materials, used decomposition method to acquire carbon quantum dots (CQDs) which can emission blue fluorescence under ultraviolet excitation. In the aspect of application, we achieved the biological imaging of CQDs in vivo and in vitro.

  11. Better team management--better team care?

    Science.gov (United States)

    Shelley, P; Powney, B

    1994-01-01

    Team building should not be a 'bolt-on' extra, it should be a well planned, integrated part of developing teams and assisting their leaders. When asked to facilitate team building by a group of NHS managers we developed a framework which enabled individual members of staff to become more effective in the way they communicated with each other, their teams and in turn within the organization. Facing the challenge posed by complex organizational changes, staff were able to use 3 training days to increase and develop their awareness of the principles of teamwork, better team management, and how a process of leadership and team building could help yield better patient care.

  12. Natural Blue Food Colour

    DEFF Research Database (Denmark)

    Roda-Serrat, Maria Cinta

    In recent years, there has been a growing tendency to avoid the use of artificial colorants and additives in food products, especially after some studies linked their consumption with behavioural changes in children. However, the incorporation of colorants from natural origin remains a challenge...... for food technologists, as these are typically less vivid and less stable than their synthetic alternatives. Regarding blue colorants, phycocyanins from cyanobacteria are currently in the spotlight as promising new natural blue colorants. Phycocyanins are proteins which blue colour results from...... the presence of the chromophore phycocyanobilin (PCB), a covalently attached linear tetrapyrrole. The applications of phycocyanins as food colorants are however limited, as they show poor stability in certain conditions of pH, light and temperature. Cleavage of PCB from the protein followed by careful product...

  13. Magneto-optical absorption in semiconducting spherical quantum dots: Influence of the dot-size, confining potential, and magnetic field

    Directory of Open Access Journals (Sweden)

    Manvir S. Kushwaha

    2014-12-01

    Full Text Available Semiconducting quantum dots – more fancifully dubbed artificial atoms – are quasi-zero dimensional, tiny, man-made systems with charge carriers completely confined in all three dimensions. The scientific quest behind the synthesis of quantum dots is to create and control future electronic and optical nanostructures engineered through tailoring size, shape, and composition. The complete confinement – or the lack of any degree of freedom for the electrons (and/or holes – in quantum dots limits the exploration of spatially localized elementary excitations such as plasmons to direct rather than reciprocal space. Here we embark on a thorough investigation of the magneto-optical absorption in semiconducting spherical quantum dots characterized by a confining harmonic potential and an applied magnetic field in the symmetric gauge. This is done within the framework of Bohm-Pines’ random-phase approximation that enables us to derive and discuss the full Dyson equation that takes proper account of the Coulomb interactions. As an application of our theoretical strategy, we compute various single-particle and many-particle phenomena such as the Fock-Darwin spectrum; Fermi energy; magneto-optical transitions; probability distribution; and the magneto-optical absorption in the quantum dots. It is observed that the role of an applied magnetic field on the absorption spectrum is comparable to that of a confining potential. Increasing (decreasing the strength of the magnetic field or the confining potential is found to be analogous to shrinking (expanding the size of the quantum dots: resulting into a blue (red shift in the absorption spectrum. The Fermi energy diminishes with both increasing magnetic-field and dot-size; and exhibits saw-tooth-like oscillations at large values of field or dot-size. Unlike laterally confined quantum dots, both (upper and lower magneto-optical transitions survive even in the extreme instances. However, the intra

  14. Magneto-optical absorption in semiconducting spherical quantum dots: Influence of the dot-size, confining potential, and magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Kushwaha, Manvir S. [Department of Physics and Astronomy, Rice University, P.O. Box 1892, Houston, TX 77251 (United States)

    2014-12-15

    Semiconducting quantum dots – more fancifully dubbed artificial atoms – are quasi-zero dimensional, tiny, man-made systems with charge carriers completely confined in all three dimensions. The scientific quest behind the synthesis of quantum dots is to create and control future electronic and optical nanostructures engineered through tailoring size, shape, and composition. The complete confinement – or the lack of any degree of freedom for the electrons (and/or holes) – in quantum dots limits the exploration of spatially localized elementary excitations such as plasmons to direct rather than reciprocal space. Here we embark on a thorough investigation of the magneto-optical absorption in semiconducting spherical quantum dots characterized by a confining harmonic potential and an applied magnetic field in the symmetric gauge. This is done within the framework of Bohm-Pines’ random-phase approximation that enables us to derive and discuss the full Dyson equation that takes proper account of the Coulomb interactions. As an application of our theoretical strategy, we compute various single-particle and many-particle phenomena such as the Fock-Darwin spectrum; Fermi energy; magneto-optical transitions; probability distribution; and the magneto-optical absorption in the quantum dots. It is observed that the role of an applied magnetic field on the absorption spectrum is comparable to that of a confining potential. Increasing (decreasing) the strength of the magnetic field or the confining potential is found to be analogous to shrinking (expanding) the size of the quantum dots: resulting into a blue (red) shift in the absorption spectrum. The Fermi energy diminishes with both increasing magnetic-field and dot-size; and exhibits saw-tooth-like oscillations at large values of field or dot-size. Unlike laterally confined quantum dots, both (upper and lower) magneto-optical transitions survive even in the extreme instances. However, the intra-Landau level

  15. Work team

    Directory of Open Access Journals (Sweden)

    RBE Editorial

    2016-06-01

    Full Text Available Work Team 2016 (Jan-Jul1. Editorial TeamChief-editorsBayardo Bapstista Torres, Instituto de Química (USP, BrasilEduardo Galembeck, Depto. Bioquímica, Instituto de Biologia, Universidade de Campinas (Unicamp, Brasil Co-editorsGabriel Gerber Hornink, Depto. Bioquímica, Instituto de Ciências Biomédicas, Universidade - Federal de Alfenas (Unifal-MG, BrasilVera Maria Treis Trindade, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul (UFRGS, Brasil Editorial BoardAdriana Cassina, Department of Biochemistry, Facultad de Medicina, Universidad de la República, UruguayAngel Herráez, Departamento de Bioquímica y Biología molecular, Universidad de Alcalá de Henares, Madrid, SpainAndré Amaral Gonçalves Bianco, Universidade Federal de São Paulo (Unifesp, BrasilDenise Vaz de Macedo, Depto. Bioquímica, Instituto de Biologia, Universidade Estadual de Campinas (Unicamp, BrasilEneida de Paula, Depto. Bioquímica, Instituto de Biologia, Universidade Estadual de Campinas (Unicamp, BrasilJose Antonio Martinez Oyanedel, Universidad de Concepción, ChileJosep Maria Fernández Novell, Department of Molecular Biology & Biochemistry, Universitat de Barcelona, SpainLeila Maria Beltramini, Instituto de Física de São Carlos, Universidade Estadual de São Paulo (USP, BrasilManuel João da Costa, Escola de Ciências da Saúde, Universidade do Minho, PortugalMaria Lucia Bianconi, Instituto de Bioquímica Médica, Universidade Federal do Rio de Janeiro (UFRJ, BrasilMaría Noel Alvarez, Department of Biochemistry, Facultad de Medicina, Universidad de la República, UruguayMiguel Ángel Medina Torres, Department of Molecular Biology & Biochemistry Faculty of Sciences University of Málaga, SpainNelma Regina Segnini Bossolan, Instituto de Física de São Carlos, Universidade de São Paulo (USP, BrasilPaulo De Avila Junior, Centro de Ciências Naturais e Humanas (CCNH Universidade Federal do ABC (UFABC

  16. A Blue Lagoon Function

    DEFF Research Database (Denmark)

    Markvorsen, Steen

    2007-01-01

    We consider a specific function of two variables whose graph surface resembles a blue lagoon. The function has a saddle point $p$, but when the function is restricted to any given straight line through $p$ it has a {\\em{strict local minimum}} along that line at $p$.......We consider a specific function of two variables whose graph surface resembles a blue lagoon. The function has a saddle point $p$, but when the function is restricted to any given straight line through $p$ it has a {\\em{strict local minimum}} along that line at $p$....

  17. Team Orientations, Interpersonal Relations, and Team Success

    Science.gov (United States)

    Nixon, Howard L.

    1976-01-01

    Contradictions in post research on the concepts of "cohesiveness" and team success seem to arise from the ways in which cohesiveness is measured and the nature of the teams investigated in each study. (MB)

  18. Team cohesion and team success in sport.

    Science.gov (United States)

    Carron, Albert V; Bray, Steven R; Eys, Mark A

    2002-02-01

    The main aim of this study was to examine the relationship between task cohesiveness and team success in elite teams using composite team estimates of cohesion. A secondary aim was to determine statistically the consistency (i.e. 'groupness') present in team members' perceptions of cohesion. Elite university basketball teams (n = 18) and club soccer teams (n = 9) were assessed for cohesiveness and winning percentages. Measures were recorded towards the end of each team's competitive season. Our results indicate that cohesiveness is a shared perception, thereby providing statistical support for the use of composite team scores. Further analyses indicated a strong relationship between cohesion and success (r = 0.55-0.67). Further research using multi-level statistical techniques is recommended.

  19. Hexagonal graphene quantum dots

    KAUST Repository

    Ghosh, Sumit; Schwingenschlö gl, Udo

    2016-01-01

    We study hexagonal graphene quantum dots, using density functional theory, to obtain a quantitative description of the electronic properties and their size dependence, considering disk and ring geometries with both armchair and zigzag edges. We show that the electronic properties of quantum dots with armchair edges are more sensitive to structural details than those with zigzag edges. As functions of the inner and outer radii, we find in the case of armchair edges that the size of the band gap follows distinct branches, while in the case of zigzag edges it changes monotonically. This behaviour is further analyzed by studying the ground state wave function and explained in terms of its localisation.

  20. Quantum dot solar cells

    CERN Document Server

    Wu, Jiang

    2013-01-01

    The third generation of solar cells includes those based on semiconductor quantum dots. This sophisticated technology applies nanotechnology and quantum mechanics theory to enhance the performance of ordinary solar cells. Although a practical application of quantum dot solar cells has yet to be achieved, a large number of theoretical calculations and experimental studies have confirmed the potential for meeting the requirement for ultra-high conversion efficiency. In this book, high-profile scientists have contributed tutorial chapters that outline the methods used in and the results of variou

  1. Hexagonal graphene quantum dots

    KAUST Repository

    Ghosh, Sumit

    2016-12-05

    We study hexagonal graphene quantum dots, using density functional theory, to obtain a quantitative description of the electronic properties and their size dependence, considering disk and ring geometries with both armchair and zigzag edges. We show that the electronic properties of quantum dots with armchair edges are more sensitive to structural details than those with zigzag edges. As functions of the inner and outer radii, we find in the case of armchair edges that the size of the band gap follows distinct branches, while in the case of zigzag edges it changes monotonically. This behaviour is further analyzed by studying the ground state wave function and explained in terms of its localisation.

  2. The "Blue Banana" Revisited

    NARCIS (Netherlands)

    Faludi, A.K.F.

    2015-01-01

    This essay is about the “Blue Banana”. Banana is the name given subsequently by others to a Dorsale européenne (European backbone) identified empirically by Roger Brunet. In a background study to the Communication of the European Commission ‘Europe 2000’, Klaus Kunzmann and Michael Wegener put

  3. Your cancer care team

    Science.gov (United States)

    ... gov/ency/patientinstructions/000929.htm Your cancer care team To use the sharing features on this page, ... help your body heal. Working with Your Care Team Each member of your care team plays an ...

  4. Ratiometric fluorescent nanosensor based on carbon dots for the detection of mercury ion

    Science.gov (United States)

    Ma, Yusha; Mei, Jing; Bai, Jianliang; Chen, Xu; Ren, Lili

    2018-05-01

    A novel ratiometric fluorescent nanosensor based on carbon dots has been synthesized via bonding rhodamine B hydrazide to the carbon dots surface by an amide reaction. The ratiometric fluorescent nanosensor showed only a single blue fluorescence emission around 450 nm. While, as mercury ion was added, due to the open-ring of rhodamine moiety bonded on the CDs surface, the orange emission of the open-ring rhodamine would increase obviously according to the concentration of mercury ion, resulting in the distinguishable dual emissions at 450 nm and 575 nm under a single 360 excitation wavelength. Meanwhile, the ratiometric fluorescent nanosensor based on carbon dots we prepared is more sensitive to qualitative and semi-quantitative detection of mercury ion in the range of 0–100 μM, because fluorescence changes gradually from blue to orange emission under 365 nm lamp with the increasing of mercury ion in the tested solution.

  5. Improvement of the luminescent properties of cadmium sulfide quantum dots by a post-synthesis modification

    Energy Technology Data Exchange (ETDEWEB)

    López, Israel; Gómez, Idalia, E-mail: maria.gomezd@uanl.edu.mx

    2014-11-15

    Here the improvement of the luminescent properties of CdS quantum dots by a post-synthesis modification with aqueous solutions of NaOH at different concentrations is presented. The CdS quantum dots were synthesized by a microwave-assisted method using citrate ions as stabilizer. The addition of the hydroxide ions increased the intensity of the orange-red emission by about 80%. Besides, a violet-blue emission was achieved by means of this post-synthesis modification. The hydroxide ions control the precipitation equilibria of the CdS and Cd(OH){sub 2}, dissolving and precipitating the surface of the quantum dots. The NaOH treatment increases the number of traps, which produces less band-edge and more deep-trap emission, which explains the decrease and increase in the intensity of the violet-blue and orange-red emissions, respectively.

  6. Improvement of the luminescent properties of cadmium sulfide quantum dots by a post-synthesis modification

    International Nuclear Information System (INIS)

    López, Israel; Gómez, Idalia

    2014-01-01

    Here the improvement of the luminescent properties of CdS quantum dots by a post-synthesis modification with aqueous solutions of NaOH at different concentrations is presented. The CdS quantum dots were synthesized by a microwave-assisted method using citrate ions as stabilizer. The addition of the hydroxide ions increased the intensity of the orange-red emission by about 80%. Besides, a violet-blue emission was achieved by means of this post-synthesis modification. The hydroxide ions control the precipitation equilibria of the CdS and Cd(OH) 2 , dissolving and precipitating the surface of the quantum dots. The NaOH treatment increases the number of traps, which produces less band-edge and more deep-trap emission, which explains the decrease and increase in the intensity of the violet-blue and orange-red emissions, respectively

  7. Quantum dots and nanocomposites.

    Science.gov (United States)

    Mansur, Herman Sander

    2010-01-01

    Quantum dots (QDs), also known as semiconducting nanoparticles, are promising zero-dimensional advanced materials because of their nanoscale size and because they can be engineered to suit particular applications such as nonlinear optical devices (NLO), electro-optical devices, and computing applications. QDs can be joined to polymers in order to produce nanocomposites which can be considered a scientific revolution of the 21st century. One of the fastest moving and most exciting interfaces of nanotechnology is the use of QDs in medicine, cell and molecular biology. Recent advances in nanomaterials have produced a new class of markers and probes by conjugating semiconductor QDs with biomolecules that have affinities for binding with selected biological structures. The nanoscale of QDs ensures that they do not scatter light at visible or longer wavelengths, which is important in order to minimize optical losses in practical applications. Moreover, at this scale, quantum confinement and surface effects become very important and therefore manipulation of the dot diameter or modification of its surface allows the properties of the dot to be controlled. Quantum confinement affects the absorption and emission of photons from the dot. Thus, the absorption edge of a material can be tuned by control of the particle size. This paper reviews developments in the myriad of possibilities for the use of semiconductor QDs associated with molecules producing novel hybrid nanocomposite systems for nanomedicine and bioengineering applications.

  8. PREFACE: Quantum Dot 2010

    Science.gov (United States)

    Taylor, Robert A.

    2010-09-01

    These conference proceedings contain the written papers of the contributions presented at Quantum Dot 2010 (QD2010). The conference was held in Nottingham, UK, on 26-30 April 2010. The conference addressed topics in research on: 1. Epitaxial quantum dots (including self-assembled and interface structures, dots defined by electrostatic gates etc): optical properties and electron transport quantum coherence effects spin phenomena optics of dots in cavities interaction with surface plasmons in metal/semiconductor structures opto-electronics applications 2. Novel QD structures: fabrication and physics of graphene dots, dots in nano-wires etc 3. Colloidal quantum dots: growth (shape control and hybrid nanocrystals such as metal/semiconductor, magnetic/semiconductor) assembly and surface functionalisation optical properties and spin dynamics electrical and magnetic properties applications (light emitting devices and solar cells, biological and medical applications, data storage, assemblers) The Editors Acknowledgements Conference Organising Committee: Maurice Skolnick (Chair) Alexander Tartakovskii (Programme Chair) Pavlos Lagoudakis (Programme Chair) Max Migliorato (Conference Secretary) Paola Borri (Publicity) Robert Taylor (Proceedings) Manus Hayne (Treasurer) Ray Murray (Sponsorship) Mohamed Henini (Local Organiser) International Advisory Committee: Yasuhiko Arakawa (Tokyo University, Japan) Manfred Bayer (Dortmund University, Germany) Sergey Gaponenko (Stepanov Institute of Physics, Minsk, Belarus) Pawel Hawrylak (NRC, Ottawa, Canada) Fritz Henneberger (Institute for Physics, Berlin, Germany) Atac Imamoglu (ETH, Zurich, Switzerland) Paul Koenraad (TU Eindhoven, Nethehrlands) Guglielmo Lanzani (Politecnico di Milano, Italy) Jungil Lee (Korea Institute of Science and Technology, Korea) Henri Mariette (CNRS-CEA, Grenoble, France) Lu Jeu Sham (San Diego, USA) Andrew Shields (Toshiba Research Europe, Cambridge, UK) Yoshihisa Yamamoto (Stanford University, USA) Artur

  9. Beginning DotNetNuke Skinning and Design

    CERN Document Server

    Hay, Andrew

    2011-01-01

    DotNetNuke is an open source framework built on top of the ASP.Net platform. While this system offers an impressive set of out-of-the-box features for public and private sites, it also includes a compelling story for folks who want to present a unique look and feel to visitors. The skinning engine inside of DotNetNuke has strengthened over the course of several years and hundreds of thousands of registered users. The success of its skin and module developer community is another key indicator of the depth and breadth of this technology. The Core Team responsible for the DotNetNuke brand has gon

  10. Team Learning in Teacher Teams: Team Entitativity as a Bridge between Teams-in-Theory and Teams-in-Practice

    Science.gov (United States)

    Vangrieken, Katrien; Dochy, Filip; Raes, Elisabeth

    2016-01-01

    This study aimed to investigate team learning in the context of teacher teams in higher vocational education. As teacher teams often do not meet all criteria included in theoretical team definitions, the construct "team entitativity" was introduced. Defined as the degree to which a group of individuals possesses the quality of being a…

  11. Tuning the Photoluminescence of Graphene Quantum Dots by Photochemical Doping with Nitrogen

    Directory of Open Access Journals (Sweden)

    Xiaofen Xu

    2017-11-01

    Full Text Available Nitrogen-doped graphene quantum dots (NGQDs were synthesized by irradiating graphene quantum dots (GQDs in an NH3 atmosphere. The photoluminescence (PL properties of the GQDs and the NGQDs samples were investigated. Compared with GQDs, a clear PL blue-shift of NGQDs could be achieved by regulating the irradiating time. The NGQDs obtained by irradiation of GQDs for 70 min had a high N content of 15.34 at % and a PL blue-shift of about 47 nm. This may be due to the fact that photochemical doping of GQDs with nitrogen can significantly enhance the contents of pyridine-like nitrogen, and also effectively decrease the contents of oxygen functional groups of NGQDs, thus leading to the observed obvious PL blue-shift.

  12. THE TRANSATLANTIC BLUE DIPLOMACY

    Directory of Open Access Journals (Sweden)

    Ioana GUTU

    2016-12-01

    Full Text Available The international diplomatic environment has reached to an unprecedented development, involving one of the newly specialized diplomatic types, namely the economic diplomacy. At the core of the fast movements in the diplomatic spheres across the Globe are the international agreements like the Transatlantic Trade and Investment Partnership (TTIP that determined diplomacy to dissolve into new subtypes, evolving from ground to the ocean and implementing new ways of achieving economic and climate sustainability. One of the newly created diplomatic spheres, is the blue ocean diplomacy that acts mainly in accordance with the rules and regulations that are being applied to the transatlantic economy. Even though TTIP encourages the increase of trade flows across the Atlantic, it will also ease the foreign investment procedures that, under the approach of keeping a sustainable environment, will represent one of the most important initiatives in implementing the blue economy concept within the framework of the transatlantic diplomacy.

  13. Speeding Up Team Learning.

    Science.gov (United States)

    Edmondson, Amy; Bohmer, Richard; Pisano, Gary

    2001-01-01

    A study of 16 cardiac surgery teams looked at how the teams adapted to new ways of working. The challenge of team management is to implement new processes as quickly as possible. Steps for creating a learning team include selecting a mix of skills and expertise, framing the challenge, and creating an environment of psychological safety. (JOW)

  14. Team Leader Structuring for Team Effectiveness and Team Learning in Command-and-Control Teams

    Science.gov (United States)

    van der Haar, Selma; Koeslag-Kreunen, Mieke; Euwe, Eline; Segers, Mien

    2017-01-01

    Due to their crucial and highly consequential task, it is of utmost importance to understand the levers leading to effectiveness of multidisciplinary emergency management command-and-control (EMCC) teams. We argue that the formal EMCC team leader needs to initiate structure in the team meetings to support organizing the work as well as facilitate team learning, especially the team learning process of constructive conflict. In a sample of 17 EMCC teams performing a realistic EMCC exercise, including one or two team meetings (28 in sum), we coded the team leader’s verbal structuring behaviors (1,704 events), rated constructive conflict by external experts, and rated team effectiveness by field experts. Results show that leaders of effective teams use structuring behaviors more often (except asking procedural questions) but decreasingly over time. They support constructive conflict by clarifying and by making summaries that conclude in a command or decision in a decreasing frequency over time. PMID:28490856

  15. Team Leader Structuring for Team Effectiveness and Team Learning in Command-and-Control Teams.

    Science.gov (United States)

    van der Haar, Selma; Koeslag-Kreunen, Mieke; Euwe, Eline; Segers, Mien

    2017-04-01

    Due to their crucial and highly consequential task, it is of utmost importance to understand the levers leading to effectiveness of multidisciplinary emergency management command-and-control (EMCC) teams. We argue that the formal EMCC team leader needs to initiate structure in the team meetings to support organizing the work as well as facilitate team learning, especially the team learning process of constructive conflict. In a sample of 17 EMCC teams performing a realistic EMCC exercise, including one or two team meetings (28 in sum), we coded the team leader's verbal structuring behaviors (1,704 events), rated constructive conflict by external experts, and rated team effectiveness by field experts. Results show that leaders of effective teams use structuring behaviors more often (except asking procedural questions) but decreasingly over time. They support constructive conflict by clarifying and by making summaries that conclude in a command or decision in a decreasing frequency over time.

  16. Trust in Diverse Teams

    DEFF Research Database (Denmark)

    Clausen, Lisbeth

    , maintaining team cohesiveness in multicultural teams to collaborate effectively presents a number of challenges. The present study employs the concept of trust to explore influences on team collaboration in high performing teams. The study is based on observation of teams in seven multinational corporations...... and interviews with managers from the US, Europe, China and Japan. The study presents a conceptual framework - a ‘trust buffer’ – which enables analysis and exemplification of the dynamics and challenges of teams as drivers of change. Each team has strategically important tasks, unique capacities and deal...... with change in particular ways: Each team is analyzed in relation to its global (HQ) mandate, local (national) stakeholders and organizational context. It is found that communication energy, resources and team mandate underscore the sense of trust in high performing teams. Diversity is understood...

  17. Time-resolved photoluminescence measurements of InP/ZnS quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Pham Thi Thuy; Ung Thi Dieu Thuy; Tran Thi Kim Chi; Le Quang Phuong; Nguyen Quang Liem [Institute of Materials Science, VAST, 18 Hoang Quoc Viet, Cau Giay, Hanoi (Viet Nam); Li Liang; Reiss, Peter [CEA Grenoble, DSM/INAC/SPrAM (UMR 5819 CEA-CNRS-Universite Joseph Fourier)/LEMOH, 17 rue des Martyrs, 38054 Grenoble cedex 9 (France)], E-mail: liemnq@ims.vast.ac.vn

    2009-09-01

    This paper reports the results on the time-resolved photoluminescence study of InP/ZnS core/shell quantum dots. The ZnS shell played a decisive role to passivate imperfections on the surface of InP quantum dots, consequently giving rise to a strong enhancement of the photoluminescence from the InP core. Under appropriate excitation conditions, not only the emission from the InP core but also that from the ZnS shell was observed. The emission peak in InP core quantum dots varied as a function of quantum dots size, ranging in the 600 - 700 nm region; while the ZnS shell showed emission in the blue region around 470 nm, which is interpreted as resulting from defects in ZnS.

  18. Testing Game-Based Performance in Team-Handball.

    Science.gov (United States)

    Wagner, Herbert; Orwat, Matthias; Hinz, Matthias; Pfusterschmied, Jürgen; Bacharach, David W; von Duvillard, Serge P; Müller, Erich

    2016-10-01

    Wagner, H, Orwat, M, Hinz, M, Pfusterschmied, J, Bacharach, DW, von Duvillard, SP, and Müller, E. Testing game-based performance in team-handball. J Strength Cond Res 30(10): 2794-2801, 2016-Team-handball is a fast paced game of defensive and offensive action that includes specific movements of jumping, passing, throwing, checking, and screening. To date and to the best of our knowledge, a game-based performance test (GBPT) for team-handball does not exist. Therefore, the aim of this study was to develop and validate such a test. Seventeen experienced team-handball players performed 2 GBPTs separated by 7 days between each test, an incremental treadmill running test, and a team-handball test game (TG) (2 × 20 minutes). Peak oxygen uptake (V[Combining Dot Above]O2peak), blood lactate concentration (BLC), heart rate (HR), sprinting time, time of offensive and defensive actions as well as running intensities, ball velocity, and jump height were measured in the game-based test. Reliability of the tests was calculated using an intraclass correlation coefficient (ICC). Additionally, we measured V[Combining Dot Above]O2peak in the incremental treadmill running test and BLC, HR, and running intensities in the team-handball TG to determine the validity of the GBPT. For the test-retest reliability, we found an ICC >0.70 for the peak BLC and HR, mean offense and defense time, as well as ball velocity that yielded an ICC >0.90 for the V[Combining Dot Above]O2peak in the GBPT. Percent walking and standing constituted 73% of total time. Moderate (18%) and high (9%) intensity running in the GBPT was similar to the team-handball TG. Our results indicated that the GBPT is a valid and reliable test to analyze team-handball performance (physiological and biomechanical variables) under conditions similar to competition.

  19. A blue-emitting CdS/dendrimer nanocomposite

    International Nuclear Information System (INIS)

    Sooklal, K.; Murphy, C.J.; Hanus, L.H.; Ploehn, H.J.

    1998-01-01

    CdS/dendrimer nanocomposites that emit blue light are formed by the arrested precipitation of nanometer-scale CdS quantum dots in the presence of starburst (poly(aminoamine)) dendrimers as the stabilizing host. The authors report a strong photoluminescence with emission maxima at about 450 nm. The optoelectronic properties of the CdS clusters are shown to be sensitive to synthesis conditions, including dendrimer type, solvent type, and the concentration of dendrimer and other solutes. Thin films of these materials prepared by solution casting retain the optoelectronic properties of the parent solutions. (orig.)

  20. High power blue LED development using different growth modes

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Dong S.; Florescu, Doru I.; Ramer, Jeff C.; Merai, Vinod; Parekh, Aniruddh; Begarney, Michael J.; Armour, Eric A. [Veeco TurboDisc Operations, 394 Elizabeth Avenue, Somerset, NJ 08873 (United States); Lu Dong [Veeco TurboDisc Operations, 394 Elizabeth Avenue, Somerset, NJ 08873 (United States); School of Engineering, Rutgers University, Piscataway, NJ 08854 (United States)

    2004-09-01

    Blue high brightness light emitting diodes (HB-LEDs) have been developed using different growth modes in the active layers. Piezoelectric field engineering improves the optical output power in multiple quantum well (MQW) LEDs by inserting an optimized transitional superlattice (TSL) before the active MQW layers. Within single quantum well (SQW) LEDs, quasi-Quantum Dot (QD) growth for Indium localization has been realized. The SQW LED output power exceeds the strain engineered MQW LEDs. The experimental data indicates that Indium localization enhances overall quantum efficiency and results in increased output power for HB-LEDs. (copyright 2004 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  1. Developing Your Dream Team

    Science.gov (United States)

    Gatlin, Kenda

    2005-01-01

    Almost anyone has held various roles on a team, be it a family unit, sports team, or a project-oriented team. As an educator, one must make a conscious decision to build and invest in a team. Gathering the best team possible will help one achieve one's goals. This article explores some of the key reasons why it is important to focus on the team…

  2. Nanocrystal quantum dots

    CERN Document Server

    Klimov, Victor I

    2010-01-01

    ""Soft"" Chemical Synthesis and Manipulation of Semiconductor Nanocrystals, J.A. Hollingsworth and V.I. Klimov Electronic Structure in Semiconductor Nanocrystals: Optical Experiment, D.J. NorrisFine Structure and Polarization Properties of Band-Edge Excitons in Semiconductor Nanocrystals, A.L. EfrosIntraband Spectroscopy and Dynamics of Colloidal Semiconductor Quantum Dots, P. Guyot-Sionnest, M. Shim, and C. WangMultiexciton Phenomena in Semiconductor Nanocrystals, V.I. KlimovOptical Dynamics in Single Semiconductor Quantum Do

  3. Quantum Dot Photonics

    Science.gov (United States)

    Kinnischtzke, Laura A.

    We report on several experiments using single excitons confined to single semiconductor quantum dots (QDs). Electric and magnetic fields have previously been used as experimental knobs to understand and control individual excitons in single quantum dots. We realize new ways of electric field control by changing materials and device geometry in the first two experiments with strain-based InAs QDs. A standard Schottky diode heterostructure is demonstrated with graphene as the Schottky gate material, and its performance is bench-marked against a diode with a standard gate material, semi-transparent nickel-chromium (NiCr). This change of materials increases the photon collection rate by eliminating absorption in the metallic NiCr layer. A second set of experiments investigates the electric field response of QDs as a possible metrology source. A linear voltage potential drop in a plane near the QDs is used to describe how the spatially varying voltage profile is also imparted on the QDs. We demonstrate a procedure to map this voltage profile as a preliminary route towards a full quantum sensor array. Lastly, InAs QDs are explored as potential spin-photon interfaces. We describe how a magnetic field is used to realize a reversible exchange of information between light and matter, including a discussion of the polarization-dependence of the photoluminesence, and how that can be linked to the spin of a resident electron or hole. We present evidence of this in two wavelength regimes for InAs quantum dots, and discuss how an external magnetic field informs the spin physics of these 2-level systems. This thesis concludes with the discovery of a new class of quantum dots. As-yet unidentified defect states in single layer tungsten diselenide (WSe 2 ) are shown to host quantum light emission. We explore the spatial extent of electron confinement and tentatively identify a radiative lifetime of 1 ns for these single photon emitters.

  4. A facile method to prepare fluorescent carbon dots and their application in selective colorimetric sensing of silver ion through the formation of silver nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Ayaz Ahmed, Khan Behlol; P, Suresh Kumar; Veerappan, Anbazhagan, E-mail: anbazhagan@scbt.sastra.edu

    2016-09-15

    Herein, we report a laboratory convenient method for the preparation of blue color emitting fluorescent carbon dots (C-dots) in 60 min by boiling the alkaline solution of pectin. The C-dots derived from pectin detects selectively silver ion by forming silver nanoparticles (AgNPs) without any irradiation or heating or additional reducing agents. As prepared AgNPs appears yellow in color and showed the characteristic surface plasmon resonance maximum at 410 nm. Transmission electron microscopy (TEM) revealed crystalline, spherical AgNPs with size range from 10–15 nm. Cyclic voltammetry study revealed that the lower reduction potential of C-dots than that of silver ion favors the reduction of Ag{sup +} to Ag°. Electrochemical impedance spectroscopy showed the charge transfer value for the redox reaction of C-dots as 200 Ωcm{sup 2}. In the presence of Ag{sup +}, C-dots fluorescence emission was turned from blue to cyan to green to colorless, accompanying the quenching and red shift in emission maximum at 450 nm. Interference study clearly showed that the C-dots have high preference for Ag{sup +} ion than the other interfering metal ions. The proposed sensor system selectively senses Ag{sup +} ion in water at micromolar concentration and also offers an easy procedure to prepare AgNPs in the presence of other interfering metal ions. - Highlights: • Blue color emitting C-dots was prepared by boiling alkaline pectin solution. • C-dots sense silver ion at micromolar concentration. • C-dots recognize silver ion in the presence of interfering metal ions. • Reduction potential of C-dots was estimated by cyclic voltammeter as – 0.2 V.

  5. Quantum dot solar cell

    International Nuclear Information System (INIS)

    Ahamefula, U.C.; Sulaiman, M.Y.; Sopian, K.; Ibarahim, Z.; Ibrahim, N.; Alghoul, M.A.; Haw, L.C.; Yahya, M.; Amin, N.; Mat, S.; Ruslan, M.H.

    2009-01-01

    Full text: The much awaited desire of replacing fossil fuel with photovoltaic will remain a fairy tale if the myriad of issues facing solar cell development are marginalized. Foremost in the list is the issue of cost. Silicon has reached a stage where its use on large scale can no longer be lavishly depended upon. The demand for high grade silicon from the microelectronics and solar industries has soared leading to scarcity. New approach has to be sought. Notable is the increased attention on thin films such as cadmium telluride, copper indium gallium diselenide, amorphous silicon, and the not so thin non-crystalline family of silicon. While efforts to address the issues of stability, toxicity and efficiency of these systems are ongoing, another novel approach is quietly making its appearance - quantum dots. Quantum dots seem to be promising candidates for solar cells because of the opportunity to manipulate their energy levels allowing absorption of a wider solar spectrum. Utilization of minute quantity of these nano structures is enough to bring the cost of solar cell down and to ascertain sustainable supply of useful material. The paper outlines the progress that has been made on quantum dot solar cells. (author)

  6. Team Effectiveness and Team Development in CSCL

    Science.gov (United States)

    Fransen, Jos; Weinberger, Armin; Kirschner, Paul A.

    2013-01-01

    There is a wealth of research on computer-supported cooperative work (CSCW) that is neglected in computer-supported collaborative learning (CSCL) research. CSCW research is concerned with contextual factors, however, that may strongly influence collaborative learning processes as well, such as task characteristics, team formation, team members'…

  7. MANAGING MULTICULTURAL PROJECT TEAMS

    Directory of Open Access Journals (Sweden)

    Cezar SCARLAT

    2014-06-01

    Full Text Available The article is based on literature review and authors’ own recent experience in managing multicultural project teams, in international environment. This comparative study considers two groups of projects: technical assistance (TA projects versus information technology (IT projects. The aim is to explore the size and structure of the project teams – according to the team formation and its lifecycle, and to identify some distinctive attributes of the project teams – both similarities and differences between the above mentioned types of projects. Distinct focus of the research is on the multiculturalism of the project teams: how the cultural background of the team members influences the team performance and team management. Besides the results of the study are the managerial implications: how the team managers could soften the cultural clash, and avoid inter-cultural misunderstandings and even conflicts – in order to get a better performance. Some practical examples are provided as well.

  8. Biodistribution study of carbogenic dots in cells and in vivo for optical imaging

    International Nuclear Information System (INIS)

    Li Nan; Liang Xiaofei; Wang Lili; Li Zonghai; Li Peiyong; Zhu Yihua; Song Jing

    2012-01-01

    Blue fluorescent carbon dots (C-dots) were synthesized and evaluated for their cytotoxicity and also for their optical imaging performance. The results showed that the C-dots could enter into the Hela cells in 15 min incubation and the uptake increased rapidly from 15 min to 2 h. In cytotoxicity study, C-dots were biocompatible and nontoxic to three human cells including two cancer cells (Hela and SMCC-7721) and one normal cell (HEK 293) in concentrations up to 500 μg/mL. Since the endocytic interference factors, including NaN 3 , MβCD, sucrose, and low temperature, could not play an inhibitory effect on C-dots entering into cells, the direct nonendocytic pathway for C-dots was speculated. The C-dots showed encouraging cell-imaging applications in vitro and in vivo. They entered into cells without any further functionalization, and the fluorescence property of these particles can be used for fluorescence-based cell-imaging applications.

  9. Effect of swift heavy ion irradiation on bare and coated ZnS quantum dots

    International Nuclear Information System (INIS)

    Chowdhury, S.; Hussain, A.M.P.; Ahmed, G.A.; Singh, F.; Avasthi, D.K.; Choudhury, A.

    2008-01-01

    The present study compares structural and optical modifications of bare and silica (SiO 2 ) coated ZnS quantum dots under swift heavy ion (SHI) irradiation. Bare and silica coated ZnS quantum dots were prepared following an inexpensive chemical route using polyvinyl alcohol (PVA) as the dielectric host matrix. X-ray diffraction (XRD) and transmission electron microscopy (TEM) study of the samples show the formation of almost spherical ZnS quantum dots. The UV-Vis absorption spectra reveal blue shift relative to bulk material in absorption energy while photoluminescence (PL) spectra suggests that surface state and near band edge emissions are dominating in case of bare and coated samples, respectively. Swift heavy ion irradiation of the samples was carried out with 160 MeV Ni 12+ ion beam with fluences 10 12 to 10 13 ions/cm 2 . Size enhancement of bare quantum dots after irradiation has been indicated in XRD and TEM analysis of the samples which has also been supported by optical absorption spectra. However similar investigations on irradiated coated quantum dots revealed little change in quantum dot size and emission. The present study thus shows that the coated ZnS quantum dots are stable upon SHI irradiation compared to the bare one

  10. Optical and Micro-Structural Characterization of MBE Grown Indium Gallium Nitride Polar Quantum Dots

    KAUST Repository

    El Afandy, Rami

    2011-07-07

    Gallium nitride and related materials have ushered in scientific and technological breakthrough for lighting, mass data storage and high power electronic applications. These III-nitride materials have found their niche in blue light emitting diodes and blue laser diodes. Despite the current development, there are still technological problems that still impede the performance of such devices. Three-dimensional nanostructures are proposed to improve the electrical and thermal properties of III-nitride optical devices. This thesis consolidates the characterization results and unveils the unique physical properties of polar indium gallium nitride quantum dots grown by molecular beam epitaxy technique. In this thesis, a theoretical overview of the physical, structural and optical properties of polar III-nitrides quantum dots will be presented. Particular emphasis will be given to properties that distinguish truncated-pyramidal III-nitride quantum dots from other III-V semiconductor based quantum dots. The optical properties of indium gallium nitride quantum dots are mainly dominated by large polarization fields, as well as quantum confinement effects. Hence, the experimental investigations for such quantum dots require performing bandgap calculations taking into account the internal strain fields, polarization fields and confinement effects. The experiments conducted in this investigation involved the transmission electron microscopy and x-ray diffraction as well as photoluminescence spectroscopy. The analysis of the temperature dependence and excitation power dependence of the PL spectra sheds light on the carrier dynamics within the quantum dots, and its underlying wetting layer. A further analysis shows that indium gallium nitride quantum dots through three-dimensional confinements are able to prevent the electronic carriers from getting thermalized into defects which grants III-nitrides quantum dot based light emitting diodes superior thermally induced optical

  11. Synthesis of fluorescent carbon dots via microwave carbonization of citric acid in presence of tetraoctylammonium ion, and their application to cellular bioimaging

    International Nuclear Information System (INIS)

    Bhaisare, Mukesh Lavkush; Talib, Abou; Khan, M. Shahnawaz; Pandey, Sunil; Wu, Hui-Fen

    2015-01-01

    A jelly-like form of carbon dots (C-dots) was prepared by microwave-assisted synthesis from citric acid in the presence of tetraoctylammonium bromide. The effect of the concentration of tetraoctylammonium bromide was examined. The synthesized carbon dots were characterized by UV–vis, XRD, FTIR, fluorescence and HR-TEM. Fluorescence extends from 350 to 600 nm, and the corresponding excitation wavelengths range from 300 to 460 nm. Quantum yields are at around 0.11. A cytotoxicity study showed carbon dots to be cell permeable and biocompatible which renders them appropriate for imaging applications. The dots were used to image HeLa cell lines via the blue fluorescence of the dots. (author)

  12. Blue ocean leadership.

    Science.gov (United States)

    Kim, W Chan; Mauborgne, Renée

    2014-05-01

    Ten years ago, two INSEAD professors broke ground by introducing "blue ocean strategy," a new model for discovering uncontested markets that are ripe for growth. In this article, they apply their concepts and tools to what is perhaps the greatest challenge of leadership: closing the gulf between the potential and the realized talent and energy of employees. Research indicates that this gulf is vast: According to Gallup, 70% of workers are disengaged from their jobs. If companies could find a way to convert them into engaged employees, the results could be transformative. The trouble is, managers lack a clear understanding of what changes they could make to bring out the best in everyone. Here, Kim and Mauborgne offer a solution to that problem: a systematic approach to uncovering, at each level of the organization, which leadership acts and activities will inspire employees to give their all, and a process for getting managers throughout the company to start doing them. Blue ocean leadership works because the managers' "customers"-that is, the people managers oversee and report to-are involved in identifying what's effective and what isn't. Moreover, the approach doesn't require leaders to alter who they are, just to undertake a different set of tasks. And that kind of change is much easier to implement and track than changes to values and mind-sets.

  13. Red or blue meeting rooms: does it matter? The impact of colour on perceived productivity, social cohesion and wellbeing

    NARCIS (Netherlands)

    Bakker, I.C.; van der Voordt, Theo; de Boon, J; Vink, P.

    2013-01-01

    The purpose of this research is to establish the influences of the colours red and blue on perceived well being, social cohesion and productivity in complex real life work conditions during regular meetings.
    Methodology: Seven regular government teams held seven regular meetings in a red, blue

  14. Synthesis of colloidal SnSe quantum dots by electron beam irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Li Zhen; Peng Liwei; Fang Yaoguo; Chen Zhiwen [Shanghai Applied Radiation Institute, Shanghai University, Shanghai 201800 (China); Pan Dengyu [Institute of Nanochemistry and Nanobiology, Shanghai University, Shanghai 201800 (China); Wu Minghong, E-mail: mhwu@staff.shu.edu.cn [Shanghai Applied Radiation Institute, Shanghai University, Shanghai 201800 (China)

    2011-12-15

    Water-soluble orthorhombic colloidal SnSe quantum dots with an average diameter of 4 nm were successfully prepared by a novel irradiation route using an electronic accelerator as a radiation source and hexadecyl trimethyl ammonium bromide (CTAB) as a surfactant. The quantum dots exhibit a large direct bandgap of 3.89 eV, greatly blue shifted compared with that of bulk SnSe (1.0 eV) due to the quantum confinement effect. The quantum dots show blue photoluminescence at {approx}420 nm. The influence of CTAB on the growth of the quantum dots was investigated and a possible reaction/growth mechanism was proposed. - Highlights: > A rapid, facile and green strategy is developed to synthesize SnSe QDs. > The raw materials are green and easily obtained. > The surfactant CTAB plays an important role in the formation of SnSe quantum dots. > The obtained SnSe QDs is well-dispersed with the average size of around 4 nm.

  15. Effect of carrier doping and external electric field on the optical properties of graphene quantum dots

    Science.gov (United States)

    Basak, Tista; Basak, Tushima

    2018-02-01

    In this paper, we demonstrate that the optical properties of finite-sized graphene quantum dots can be effectively controlled by doping it with different types of charge carriers (electron/hole). In addition, the role played by a suitably directed external electric field on the optical absorption of charge-doped graphene quantum dots have also been elucidated. The computations have been performed on diamond-shaped graphene quantum dot (DQD) within the framework of the Pariser-Parr-Pople (PPP) model Hamiltonian, which takes into account long-range Coulomb interactions. Our results reveal that the energy band-gap increases when the DQD is doped with holes while it decreases on doping it with electrons. Further, the optical absorption spectra of DQD exhibits red/blue-shift on doping with electrons/holes. Our computations also indicate that the application of external transverse electric field results in a substantial blue-shift of the optical spectrum for charge-doped DQD. However, it is observed that the influence of charge-doping is more prominent in tuning the optical properties of finite-sized graphene quantum dots as compared to externally applied electric field. Thus, tailoring the optical properties of finite-sized graphene quantum dots by manipulative doping with charge carriers and suitably aligned external electric field can greatly enhance its potential application in designing nano-photonic devices.

  16. Tiger Team audits

    International Nuclear Information System (INIS)

    Cheney, G.T.

    1992-01-01

    This paper will address the purpose, scope, and approach of the Department of Energy Tiger Team Assessments. It will use the Tiger Team Assessment experience of Sandia National Laboratories at Albuquerque, New Mexico, as illustration

  17. Transforming Virtual Teams

    DEFF Research Database (Denmark)

    Bjørn, Pernille

    2005-01-01

    Investigating virtual team collaboration in industry using grounded theory this paper presents the in-dept analysis of empirical work conducted in a global organization of 100.000 employees where a global virtual team with participants from Sweden, United Kingdom, Canada, and North America were...... studied. The research question investigated is how collaboration is negotiated within virtual teams? This paper presents findings concerning how collaboration is negotiated within a virtual team and elaborate the difficulties due to invisible articulation work and managing multiple communities...... in transforming the virtual team into a community. It is argued that translucence in communication structures within the virtual team and between team and management is essential for engaging in a positive transformation process of trustworthiness supporting the team becoming a community, managing the immanent...

  18. Leadership Team | Wind | NREL

    Science.gov (United States)

    Leadership Team Leadership Team Learn more about the expertise and technical skills of the wind Initiative and provides leadership in the focus areas of high-fidelity modeling, wind power plant controls

  19. Teaming up for learning

    NARCIS (Netherlands)

    Fransen, Jos

    2012-01-01

    Fransen, J. (2012). Teaming up for learning: Team effectiveness in collaborative learning in higher education (Doctoral dissertation). November, 16, 2012, Open University in the Netherlands (CELSTEC), Heerlen, The Netherlands.

  20. Culture and teams.

    Science.gov (United States)

    Kirkman, Bradley L; Shapiro, Debra L; Lu, Shuye; McGurrin, Daniel P

    2016-04-01

    We first review research on culture effects in teams, illustrating that mean levels of team cultural values have main (i.e. direct) effects, indirect effects (i.e. mediated by intervening variables), and moderating influences on team processes and outcomes. Variance in team cultural values or on country of origin (i.e. nationality diversity) also has main effects on team functioning, and we highlight contextual variables that strengthen or weaken these main effects. We next review research examining the effect of variance in team cultural values on global virtual teams, specifically. Finally, we review research on how cultural values shape employees' receptivity to empowering leadership behavior in teams. We conclude by discussing critical areas for future research. Published by Elsevier Ltd.

  1. Your Dialysis Care Team

    Science.gov (United States)

    ... A to Z Health Guide Your Dialysis Care Team Tweet Share Print Email Good health care is ... dialyzers (artificial kidneys) for reuse. Vascular Access Care Team If you are a hemodialysis patient, another group ...

  2. Building multidisciplinary business teams

    International Nuclear Information System (INIS)

    Dyson, C.J.; Winte, N.C.

    1991-01-01

    This paper is a description of an approach to managing Exploration and Production assets through the operation of multidisciplinary business teams. The business team approach can assist in improved asset performance in terms of efficiency, motivation and business results, compared with more traditional matrix style hierarchies. Within this paper certain critical success factors for the long term success of multidiscipline teams are outlined, together with some of the risk of business team operation

  3. Toward Learning Teams

    DEFF Research Database (Denmark)

    Hoda, Rashina; Babb, Jeff; Nørbjerg, Jacob

    2013-01-01

    to sacrifice learning-focused practices. Effective learning under pressure involves conscious efforts to implement original agile practices such as retrospectives and adapted strategies such as learning spikes. Teams, their management, and customers must all recognize the importance of creating learning teams......Today's software development challenges require learning teams that can continuously apply new engineering and management practices, new and complex technical skills, cross-functional skills, and experiential lessons learned. The pressure of delivering working software often forces software teams...

  4. Formalization of Team Creation

    OpenAIRE

    Cerman, Tomáš

    2010-01-01

    This paper is divided to practical and theoretical part. Theoretical part defines essential background of personality and work psychology which are pillars for using the personality and roles typology in practical part. I also define conceptions such as group, team, procedures of making the team. Practical part is focused at making the repertoary grid which outlines proximity of team roles, anchored in the repertoary grids upon personal atributes basis and picked team positions.

  5. Workload Measurement in Human Autonomy Teaming: How and Why?

    Science.gov (United States)

    Shively, Jay

    2016-01-01

    This is an invited talk on autonomy and workload for an AFRL Blue Sky workshop sponsored by the Florida Institute for Human Machine Studies. The presentation reviews various metrics of workload and how to move forward with measuring workload in a human-autonomy teaming environment.

  6. Silicon quantum dots: surface matters

    Czech Academy of Sciences Publication Activity Database

    Dohnalová, K.; Gregorkiewicz, T.; Kůsová, Kateřina

    2014-01-01

    Roč. 26, č. 17 (2014), 1-28 ISSN 0953-8984 R&D Projects: GA ČR GPP204/12/P235 Institutional support: RVO:68378271 Keywords : silicon quantum dots * quantum dot * surface chemistry * quantum confinement Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.346, year: 2014

  7. Structuring Effective Student Teams.

    Science.gov (United States)

    Dickson, Ellen L.

    1997-01-01

    Experience with student teams working on policy analysis projects indicates the need for faculty supervision of teams in the process of addressing complex issues. The problem-solving approach adopted in one policy analysis course is described, including assignments and tasks, issues and sponsors, team dynamics, conflict management, and the…

  8. Fostering teachers' team learning

    NARCIS (Netherlands)

    Bouwmans, Machiel; Runhaar, Piety; Wesselink, Renate; Mulder, Martin

    2017-01-01

    The implementation of educational innovations by teachers seems to benefit from a team approach and team learning. The study's goal is to examine to what extent transformational leadership is associated with team learning, and to investigate the mediating roles of participative decision-making,

  9. Leadership for Distributed Teams

    NARCIS (Netherlands)

    De Rooij, J.P.G.

    2009-01-01

    The aim of this dissertation was to study the little examined, yet important issue of leadership for distributed teams. Distributed teams are defined as: “teams of which members are geographically distributed and are therefore working predominantly via mediated communication means on an

  10. InAs(Sb) quantum dots grown on GaAs by MBE

    International Nuclear Information System (INIS)

    Sallet, V.; Patriarche, G.; Mauguin, O.; Largeau, L.; Travers, L.

    2006-01-01

    The MBE growth of InAs(Sb)/GaAs quantum dots is investigated. Photoluminescence shows a slight red-shift of the emission wavelength from 1.15 to 1.24 μm (InAs 0.95 Sb 0.05 dots). Attempts to incorporate higher concentrations of antimony lead to a poor optical quality and, occasionally, to a blue-shift. Trans-mission electron microscopy observations are discussed considering the surfactant effect of antimony. (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  11. The impact of team familiarity and team leader experience on team coordination errors: A panel analysis of professional basketball teams

    NARCIS (Netherlands)

    Sieweke, Jost; Zhao, B.

    2015-01-01

    To explore the dynamics involved in team coordination, we examine the impact of team familiarity and team leader experience on team coordination errors (TCEs). We argue that team familiarity has a U-shaped effect on TCEs. We study the moderating effects of team leader prior experience and team

  12. Simple process of hybrid white quantum dot/organic light-emitting diodes by using quantum dot plate and fluorescence

    Science.gov (United States)

    Lee, Ho Won; Lee, Ki-Heon; Lee, Jae Woo; Kim, Jong-Hoon; Yang, Heesun; Kim, Young Kwan

    2015-02-01

    In this work, the simple process of hybrid quantum dot (QD)/organic light-emitting diode (OLED) was proposed to apply a white illumination light by using QD plate and organic fluorescence. Conventional blue fluorescent OLEDs were firstly fabricated and then QD plates of various concentrations, which can be controlled of UV-vis absorption and photoluminescence spectrum, were attached under glass substrate of completed blue devices. The suggested process indicates that we could fabricate the white device through very simple process without any deposition of orange or red organic emitters. Therefore, this work would be demonstrated that the potential simple process for white applications can be applied and also can be extended to additional research on light applications.

  13. Instant BlueStacks

    CERN Document Server

    Judge, Gary

    2013-01-01

    Get to grips with a new technology, understand what it is and what it can do for you, and then get to work with the most important features and tasks. A fast-paced, example-based approach guide for learning BlueStacks.This book is for anyone with a Mac or PC who wants to run Android apps on their computer. Whether you want to play games that are freely available for Android but not your computer, or you want to try apps before you install them on a physical device or use it as a development tool, this book will show you how. No previous experience is needed as this is written in plain English

  14. Printer model for dot-on-dot halftone screens

    Science.gov (United States)

    Balasubramanian, Raja

    1995-04-01

    A printer model is described for dot-on-dot halftone screens. For a given input CMYK signal, the model predicts the resulting spectral reflectance of the printed patch. The model is derived in two steps. First, the C, M, Y, K dot growth functions are determined which relate the input digital value to the actual dot area coverages of the colorants. Next, the reflectance of a patch is predicted as a weighted combination of the reflectances of the four solid C, M, Y, K patches and their various overlays. This approach is analogous to the Neugebauer model, with the random mixing equations being replaced by dot-on-dot mixing equations. A Yule-Neilsen correction factor is incorporated to account for light scattering within the paper. The dot area functions and Yule-Neilsen parameter are chosen to optimize the fit to a set of training data. The model is also extended to a cellular framework, requiring additional measurements. The model is tested with a four color xerographic printer employing a line-on-line halftone screen. CIE L*a*b* errors are obtained between measurements and model predictions. The Yule-Neilsen factor significantly decreases the model error. Accuracy is also increased with the use of a cellular framework.

  15. 75 FR 15765 - Request for Comments on Carriers' Temporary Exemption Requests From DOT's Tarmac Delay Rules for...

    Science.gov (United States)

    2010-03-30

    ... Comments on Carriers' Temporary Exemption Requests From DOT's Tarmac Delay Rules for JFK, EWR, LGA and PHL.... 46301. Jet Blue, American, and Delta recently requested an exemption from the tarmac delay rules for... from the tarmac delay rules because of the JFK runway construction to ensure that the very purpose of...

  16. Blue Guardian: open architecture intelligence, surveillance, and reconnaissance (ISR) demonstrations

    Science.gov (United States)

    Shirey, Russell G.; Borntrager, Luke A.; Soine, Andrew T.; Green, David M.

    2017-04-01

    The Air Force Research Laboratory (AFRL) - Sensors Directorate has developed the Blue Guardian program to demonstrate advanced sensing technology utilizing open architectures in operationally relevant environments. Blue Guardian has adopted the core concepts and principles of the Air Force Rapid Capabilities Office (AFRCO) Open Mission Systems (OMS) initiative to implement an open Intelligence, Surveillance and Reconnaissance (ISR) platform architecture. Using this new OMS standard provides a business case to reduce cost and program schedules for industry and the Department of Defense (DoD). Blue Guardian is an early adopting program of OMS and provides much needed science and technology improvements, development, testing, and implementation of OMS for ISR purposes. This paper presents results and lessons learned under the Blue Guardian Project Shepherd program which conducted Multi-INT operational demonstrations in the Joint Interagency Task Force - South (JIATF-S) and USSOUTHCOM area of operations in early 2016. Further, on-going research is discussed to enhance Blue Guardian Multi-INT ISR capabilities to support additional mission sets and platforms, including unmanned operations over line of sight (LOS) and beyond line of sight (BLOS) datalinks. An implementation of additional OMS message sets and services to support off-platform sensor command and control using OMS/UCI data structures and dissemination of sensor product data/metadata is explored. Lastly, the Blue Guardian team is working with the AgilePod program to use OMS in a full Government Data Rights Pod to rapidly swap these sensors to different aircraft. The union of the AgilePod (which uses SOSA compliant standards) and OMS technologies under Blue Guardian programs is discussed.

  17. 78 FR 18674 - Invitation for Public Comment on Draft DOT Research, Development and Technology Strategic Plan...

    Science.gov (United States)

    2013-03-27

    ... and strategic process to cover the years 2013-2018, and responds to feedback from the National... administrations. Two cross-modal bodies participated in the process: the RD&T Planning Team Council (composed of...-0002] Invitation for Public Comment on Draft DOT Research, Development and Technology Strategic Plan...

  18. A sol-gel based molecular imprint incorporating carbon dots for fluorometric determination of nicotinic acid

    International Nuclear Information System (INIS)

    Zuo, Pengli; Gao, Junfa; Liu, Jianha; Zhao, Mingming; Zhao, Jiahong; Peng, Jun; Zuo, Pengjian; He, Hua

    2016-01-01

    We are introducing functionalized carbon dots (C-dots) coated with a shell of molecularly imprinted sol-gel as a new tool in molecular imprint-based detection. Specifically, an imprint recognizing nicotinic acid (NA) was prepared in two steps. The first involves pyrolytic decomposition of citric acid in the presence of aminopropyltriethoxysilane to yield triethoxysilyl-modified C-dots with a typical size of 2.8 ± 1.1 nm. These are then polycondensed in the presence of tetraethoxysilane and NA at room temperature to give spherical silica nanoparticles (SiNPs) with a typical size of ∼300 nm and containing C-dots and NA in the silica matrix. NA was then removed by extraction. The resulting SiNPs are well permeable to NA, photostable, display strong blue luminescence and can bind NA fairly selectively. The fluorometric detection scheme is based on the finding that increasing concentrations of NA quench the fluorescence of the C-dots in the SiNPs. NA can be determined by this method in the 0.5 to 10.5 μM concentration range, with a 12.6 nM detection limit. The composite was successfully utilized as a fluorescent probe for the determination of NA in spiked human urine samples. The method is believed to have a wider scope in being applicable to other analytes that are capable of quenching the fluorescence of C-dots. (author)

  19. Mechanofluorochromic Carbon Nanodots: Controllable Pressure-Triggered Blue- and Red-Shifted Photoluminescence.

    Science.gov (United States)

    Liu, Cui; Xiao, Guanjun; Yang, Mengli; Zou, Bo; Zhang, Zhi-Ling; Pang, Dai-Wen

    2018-02-12

    Mechanofluorochromic materials, which change their photoluminescence (PL) colors in responding to mechanical stimuli, can be used as mechanosensors, security papers, and photoelectronic devices. However, traditional mechanofluorochromic materials can only be adjusted to a monotone direction upon the external stimuli. Controllable pressure-triggered blue- and red-shifted PL is reported for C-dots. The origin of mechanofluorochromism (MFC) in C-dots is interpreted based on structure-property relationships. The carbonyl group and the π-conjugated system play key roles in the PL change of C-dots under high pressure. As the pressure increases, the enhanced π-π stacking of the π-conjugated system causes the red-shift of PL, while the conversion of carbonyl groups eventually induces a blue-shift. Together with their low toxicity, good hydrophilicity, and small size, the tunable MFC property would boost various potential applications of C-dots. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Graphene based quantum dots.

    Science.gov (United States)

    Zhang, H G; Hu, H; Pan, Y; Mao, J H; Gao, M; Guo, H M; Du, S X; Greber, T; Gao, H-J

    2010-08-04

    Laterally localized electronic states are identified on a single layer of graphene on ruthenium by low temperature scanning tunneling spectroscopy (STS). The individual states are separated by 3 nm and comprise regions of about 90 carbon atoms. This constitutes a highly regular quantum dot-array with molecular precision. It is evidenced by quantum well resonances (QWRs) with energies that relate to the corrugation of the graphene layer. The dI/dV conductance spectra are modeled by a layer height dependent potential-well with a delta-function potential that describes the barrier for electron penetration into graphene. The resulting QWRs are strongest and lowest in energy on the isolated 'hill' regions with a diameter of 2 nm, where the graphene is decoupled from the surface.

  1. When Teams Fail to Self-Regulate: Predictors and Outcomes of Team Procrastination Among Debating Teams.

    Science.gov (United States)

    Van Hooft, Edwin A J; Van Mierlo, Heleen

    2018-01-01

    Models of team development have indicated that teams typically engage in task delay during the first stages of the team's life cycle. An important question is to what extent this equally applies to all teams, or whether there is variation across teams in the amount of task delay. The present study introduces the concept of team procrastination as a lens through which we can examine whether teams collectively engage in unplanned, voluntary, and irrational delay of team tasks. Based on theory and research on self-regulation, team processes, and team motivation we developed a conceptual multilevel model of predictors and outcomes of team procrastination. In a sample of 209 student debating teams, we investigated whether and why teams engage in collective procrastination as a team, and what consequences team procrastination has in terms of team member well-being and team performance. The results supported the existence of team procrastination as a team-level construct that has some stability over time. The teams' composition in terms of individual-level trait procrastination, as well as the teams' motivational states (i.e., team learning goal orientation, team performance-approach goal orientation in interaction with team efficacy) predicted team procrastination. Team procrastination related positively to team members' stress levels, especially for those low on trait procrastination. Furthermore, team procrastination had an indirect negative relationship with team performance, through teams' collective stress levels. These findings add to the theoretical understanding of self-regulatory processes of teams, and highlight the practical importance of paying attention to team-level states and processes such as team goal orientation and team procrastination.

  2. Interpersonal team leadership skills.

    Science.gov (United States)

    Nelson, M

    1995-05-01

    To say that a team leader's job is a tough one is certainly not saying enough. It is up to the team leader to manage a group of people to be individuals but yet work as a team. The team leader must keep the peace and yet create a revolution with this group all at the same time. The good leader will require a lot of education, training, and tons of practical application to be a success. The good news, however, is that the team leader's job is a rewarding one, one that they'll always feel good about if they do it right. How many of us get the opportunity to take a group of wonderful, thinking individual minds and pull from them ideas that a whole team can take to success? Yes, the job is indeed tough, but the paybacks are many.

  3. Managing multicultural teams.

    Science.gov (United States)

    Brett, Jeanne; Behfar, Kristin; Kern, Mary C

    2006-11-01

    Multicultural teams offer a number of advantages to international firms, including deep knowledge of different product markets, culturally sensitive customer service, and 24-hour work rotations. But those advantages may be outweighed by problems stemming from cultural differences, which can seriously impair the effectiveness of a team or even bring itto a stalemate. How can managers best cope with culture-based challenges? The authors conducted in-depth interviews with managers and members of multicultural teams from all over the world. Drawing on their extensive research on dispute resolution and teamwork and those interviews, they identify four problem categories that can create barriers to a team's success: direct versus indirect communication, trouble with accents and fluency, differing attitudes toward hierarchy and authority, and conflicting norms for decision making. If a manager--or a team member--can pinpoint the root cause of the problem, he or she is likelier to select an appropriate strategy for solving it. The most successful teams and managers, the authors found, dealt with multicultural challenges in one of four ways: adaptation (acknowledging cultural gaps openly and working around them), structural intervention (changing the shape or makeup of the team), managerial intervention (setting norms early or bringing in a higher-level manager), and exit (removing a team member when other options have failed). Which strategy is best depends on the particular circumstances--and each has potential complications. In general, though, managers who intervene early and set norms; teams and managers who try to engage everyone on the team; and teams that can see challenges as stemming from culture, not personality, succeed in solving culture-based problems with good humor and creativity. They are the likeliest to harvest the benefits inherent in multicultural teams.

  4. The NPD team conflict

    DEFF Research Database (Denmark)

    Ma, Zheng; Lin, Chih-Cheng; Tanev, Stoyan

    2012-01-01

    elaborates on the role of culture diversity and geographical dispersion in NPD team conflict. A simulation is conducted where organizations may be regarded as complex systems to affect the team conflict with a variety of influences. The results firstly indicate that there are two dimensions of NPD team...... conflict: stable and unstable dimensions with four elements: task characteristics, group members’ relationship, cultural diversity and geographical dispersion; secondly, there are two phenomena whereby the geographical dispersion influences the NPD team interaction, and the influence between cultural...

  5. PennDOT : fact book

    Science.gov (United States)

    2008-06-01

    PennDOT was created in 1970 when the former : Department of Highways was merged with transportation related : functions from the Departments of Revenue, : Commerce, Community Affairs and Military Affairs. With : an annual budget of about $5.4 billion...

  6. Quantum dots: Rethinking the electronics

    Energy Technology Data Exchange (ETDEWEB)

    Bishnoi, Dimple [Department of Physics, S. S. Jain Subodh PG College, Jaipur, Rajasthan Pin-302004 (India)

    2016-05-06

    In this paper, we demonstrate theoretically that the Quantum dots are quite interesting for the electronics industry. Semiconductor quantum dots (QDs) are nanometer-scale crystals, which have unique photo physical, quantum electrical properties, size-dependent optical properties, There small size means that electrons do not have to travel as far as with larger particles, thus electronic devices can operate faster. Cheaper than modern commercial solar cells while making use of a wider variety of photon energies, including “waste heat” from the sun’s energy. Quantum dots can be used in tandem cells, which are multi junction photovoltaic cells or in the intermediate band setup. PbSe (lead selenide) is commonly used in quantum dot solar cells.

  7. DOT Official County Highway Map

    Data.gov (United States)

    Minnesota Department of Natural Resources — The County Highway Map theme is a scanned and rectified version of the original MnDOT County Highway Map Series. The cultural features on some of these maps may be...

  8. Photoionization cross section in a spherical quantum dot: Effects of some parabolic confining electric potentials

    Directory of Open Access Journals (Sweden)

    M. Tshipa

    2017-12-01

    Full Text Available A theoretical investigation of the effects of spatial variation of confining electric potential on photoionization cross section (PCS in a spherical quantum dot is presented. The potential profiles considered here are the shifted parabolic potential and the inverse lateral shifted parabolic potential compared with the well-studied parabolic potential. The primary findings are that parabolic potential and the inverse lateral shifted parabolic potential blue shift the peaks of the PCS while the shifted parabolic potential causes a red shift.

  9. Quadra-Quantum Dots and Related Patterns of Quantum Dot Molecules: Basic Nanostructures for Quantum Dot Cellular Automata Application

    Directory of Open Access Journals (Sweden)

    Somsak Panyakeow

    2010-10-01

    Full Text Available Laterally close-packed quantum dots (QDs called quantum dot molecules (QDMs are grown by modified molecular beam epitaxy (MBE. Quantum dots could be aligned and cross hatched. Quantum rings (QRs created from quantum dot transformation during thin or partial capping are used as templates for the formations of bi-quantum dot molecules (Bi-QDMs and quantum dot rings (QDRs. Preferable quantum dot nanostructure for quantum computation based on quantum dot cellular automata (QCA is laterally close-packed quantum dot molecules having four quantum dots at the corners of square configuration. These four quantum dot sets are called quadra-quantum dots (QQDs. Aligned quadra-quantum dots with two electron confinements work like a wire for digital information transmission by Coulomb repulsion force, which is fast and consumes little power. Combination of quadra-quantum dots in line and their cross-over works as logic gates and memory bits. Molecular Beam Epitaxial growth technique called 'Droplet Epitaxy' has been developed for several quantum nanostructures such as quantum rings and quantum dot rings. Quantum rings are prepared by using 20 ML In-Ga (15:85 droplets deposited on a GaAs substrate at 390'C with a droplet growth rate of 1ML/s. Arsenic flux (7'8'10-6Torr is then exposed for InGaAs crystallization at 200'C for 5 min. During droplet epitaxy at a high droplet thickness and high temperature, out-diffusion from the centre of droplets occurs under anisotropic strain. This leads to quantum ring structures having non-uniform ring stripes and deep square-shaped nanoholes. Using these peculiar quantum rings as templates, four quantum dots situated at the corners of a square shape are regrown. Two of these four quantum dots are aligned either or, which are preferable crystallographic directions of quantum dot alignment in general.

  10. The quantum mechanical description of the dot-dot interaction in ionic colloids

    International Nuclear Information System (INIS)

    Morais, P.C.; Qu, Fanyao

    2007-01-01

    In this study the dot-dot interaction in ionic colloids is systematically investigated by self-consistently solving the coupled Schroedinger and Poisson equations in the frame of finite difference method (FDM). In a first approximation the interacting two-dot system (dimer) is described using the picture of two coupled quantum wells. It was found that the dot-dot interaction changes the colloid characteristic by changing the hopping coefficient (t) and consequently the nanodot surface charge density (σ). The hopping coefficient and the surface charge density were investigated as a function of the dot size and dot-dot distance

  11. Photometry of faint blue stars

    International Nuclear Information System (INIS)

    Kilkenny, D.; Hill, P.W.; Brown, A.

    1977-01-01

    Photometry on the uvby system is given for 61 faint blue stars. The stars are classified by means of the Stromgren indices, using criteria described in a previous paper (Kilkenny and Hill (1975)). (author)

  12. Ecology of blue straggler stars

    CERN Document Server

    Carraro, Giovanni; Beccari, Giacomo

    2015-01-01

    The existence of blue straggler stars, which appear younger, hotter, and more massive than their siblings, is at odds with a simple picture of stellar evolution. Such stars should have exhausted their nuclear fuel and evolved long ago to become cooling white dwarfs. They are found to exist in globular clusters, open clusters, dwarf spheroidal galaxies of the Local Group, OB associations and as field stars. This book summarises the many advances in observational and theoretical work dedicated to blue straggler stars. Carefully edited extended contributions by well-known experts in the field cover all the relevant aspects of blue straggler stars research: Observations of blue straggler stars in their various environments; Binary stars and formation channels; Dynamics of globular clusters; Interpretation of observational data and comparison with models. The book also offers an introductory chapter on stellar evolution written by the editors of the book.

  13. China Mobile: Expanding "Blue Ocean"

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Driving force is crucial for realizing high-speed growth. The strong driving force from "Blue Ocean Strategy" is an important advantage for China Mobile to realize harmonious and leap-forward development.

  14. Expanding the Advising Team.

    Science.gov (United States)

    Glennen, Robert E.; And Others

    1989-01-01

    The process and results of team building by Emporia State University's centralized advising center are examined from the perspectives of president, enrollment management, centralized advising, and faculty. The effort demonstrates that administrative, state, and team commitment can produce positive results in freshman retention, higher graduation…

  15. Cooperative Team Networks

    Science.gov (United States)

    2016-06-01

    team processes, such as identifying motifs of dynamic communication exchanges which goes well beyond simple dyadic and triadic configurations; as well...new metrics and ways to formulate team processes, such as identifying motifs of dynamic communication exchanges which goes well beyond simple dyadic ...sensing, communication , information, and decision networks - Darryl Ahner (AFIT: Air Force Inst Tech) Panel Session: Mathematical Models of

  16. Interactive Team Cognition

    Science.gov (United States)

    Cooke, Nancy J.; Gorman, Jamie C.; Myers, Christopher W.; Duran, Jasmine L.

    2013-01-01

    Cognition in work teams has been predominantly understood and explained in terms of shared cognition with a focus on the similarity of static knowledge structures across individual team members. Inspired by the current zeitgeist in cognitive science, as well as by empirical data and pragmatic concerns, we offer an alternative theory of team…

  17. Climate Action Team

    Science.gov (United States)

    Science Partnerships Contact Us Climate Action Team & Climate Action Initiative The Climate Action programs and the state's Climate Adaptation Strategy. The CAT members are state agency secretaries and the . See CAT reports Climate Action Team Pages CAT Home Members Working Groups Reports Back to Top

  18. Team Leadership in Practice.

    Science.gov (United States)

    Neck, Christopher; Manz, Charles C.; Manz, Karen P.

    1998-01-01

    Although educational teams can help reduce teachers' feelings of isolation and enhance instruction, ineffective leadership often dooms their efforts. This article describes four team leadership approaches: "strong-man,""transactor,""visionary hero," and "SuperLeadership." The last is superior, since it…

  19. Gender diversity in teams

    OpenAIRE

    Ghazala Azmat

    2014-01-01

    Women’s representation on corporate boards, political committees, and other teams is increasing, in part because of legal mandates. Data on team dynamics and gender differences in preferences (risk-taking behavior, taste for competition, prosocial behavior) show how gender composition influences group decision-making and subsequent performance through channels such as investment decisions, internal management, corporate governance, and social responsibility.

  20. Trust in agile teams

    DEFF Research Database (Denmark)

    Tjørnehøj, Gitte; Fransgård, Mette; Skalkam, Signe

    2012-01-01

    actions influenced this. We see two important lessons from the analysis. First the agile practices of daily Scrum and self organizing team can empower DSD teams to manage their own development of trust and thereby alleviate the obstacles of DSD. Second if management fails to support the development...

  1. Morphological and luminescent characteristics of GaN dots deposited on AlN by alternate supply of TMG and NH3

    International Nuclear Information System (INIS)

    Tsai, Y.-L.; Gong, J.-R.; Lin, T.-Y.; Lin, H.-Y.; Chen, Yang-Fang; Lin, K.-M.

    2006-01-01

    GaN dots were deposited on AlN underlayers by alternate supply of trimethylgallium (TMG) and ammonia (NH 3 ) in an inductively heated quartz reactor operated at atmospheric pressure. Various growth parameters including deposition temperature, TMG admittance and pulse time between TMG and NH 3 exposures were proposed to investigate the influence of growth parameters on the size distribution of GaN dots. It appears that GaN dots with uniform size distribution can be achieved under certain growth conditions. Based on the study of atomic force microscopy (AFM), high deposition temperature was found to be in favor of forming large GaN dots with small dot density. Decrement of TMG flow rate or reduction in the number of growth cycle tends to enable the formation of GaN dots with small dot sizes. The results of room temperature (RT) cathodoluminescence (CL) measurements of the GaN dots exhibit an emission peak at 3.735 eV. A remarkable blue shift of GaN dot emission was observed by reduced temperature photoluminescence (PL) measurements

  2. Morphological and luminescent characteristics of GaN dots deposited on AlN by alternate supply of TMG and NH{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Tsai, Y.-L. [Department of Materials Science and Engineering, Feng Chia University, Taichung 407, Taiwan (China); Gong, J.-R. [Institute of Opto-Mechatronics, National Chung Cheng University, Chiayi 621, Taiwan (China); Lin, T.-Y. [Institute of Optoelectronic Sciences, National Taiwan Ocean University, Keelung 202, Taiwan (China); Lin, H.-Y. [Department of Physics, National Taiwan University, Taipei 106, Taiwan (China); Chen, Yang-Fang [Department of Physics, National Taiwan University, Taipei 106, Taiwan (China); Lin, K.-M. [Department of Materials Science and Engineering, Feng Chia University, Taichung 407, Taiwan (China)

    2006-03-15

    GaN dots were deposited on AlN underlayers by alternate supply of trimethylgallium (TMG) and ammonia (NH{sub 3}) in an inductively heated quartz reactor operated at atmospheric pressure. Various growth parameters including deposition temperature, TMG admittance and pulse time between TMG and NH{sub 3} exposures were proposed to investigate the influence of growth parameters on the size distribution of GaN dots. It appears that GaN dots with uniform size distribution can be achieved under certain growth conditions. Based on the study of atomic force microscopy (AFM), high deposition temperature was found to be in favor of forming large GaN dots with small dot density. Decrement of TMG flow rate or reduction in the number of growth cycle tends to enable the formation of GaN dots with small dot sizes. The results of room temperature (RT) cathodoluminescence (CL) measurements of the GaN dots exhibit an emission peak at 3.735 eV. A remarkable blue shift of GaN dot emission was observed by reduced temperature photoluminescence (PL) measurements.

  3. Electron correlations in quantum dots

    International Nuclear Information System (INIS)

    Tipton, Denver Leonard John

    2001-01-01

    Quantum dot structures confine electrons in a small region of space. Some properties of semiconductor quantum dots, such as the discrete energy levels and shell filling effects visible in addition spectra, have analogies to those of atoms and indeed dots are sometimes referred to as 'artificial atoms'. However, atoms and dots show some fundamental differences due to electron correlations. For real atoms, the kinetic energy of electrons dominates over their mutual Coulomb repulsion energy and for this reason the independent electron approximation works well. For quantum dots the confining potential may be shallower than that of real atoms leading to lower electron densities and a dominance of mutual Coulomb repulsion over kinetic energy. In this strongly correlated regime the independent electron picture leads to qualitatively incorrect results. This thesis concentrates on few-electron quantum dots in the strongly correlated regime both for quasi-one-dimensional and two-dimensional dots in a square confining potential. In this so-called 'Wigner' regime the ground-state electronic charge density is localised near positions of classical electrostatic minima and the interacting electronic spectrum consists of well separated spin multiplets. In the strongly correlated regime the structure of low-energy multiplets is explained by mapping onto lattice models with extended-Hubbard and Heisenberg effective Hamiltonians. The parameters for these effective models are calculated within a Hartree approximation and are shown to reproduce well the exact results obtained by numerical diagonalisation of the full interacting Hamiltonian. Comparison is made between square dots and quantum rings with full rotational symmetry. In the very low-density regime, direct diagonalisation becomes impractical due to excessive computer time for convergence. In this regime a numerical renormalisation group method is applied to one-dimensional dots, enabling effective spin-interactions to be

  4. When Teams Fail to Self-Regulate: Predictors and Outcomes of Team Procrastination Among Debating Teams

    Science.gov (United States)

    Van Hooft, Edwin A. J.; Van Mierlo, Heleen

    2018-01-01

    Models of team development have indicated that teams typically engage in task delay during the first stages of the team’s life cycle. An important question is to what extent this equally applies to all teams, or whether there is variation across teams in the amount of task delay. The present study introduces the concept of team procrastination as a lens through which we can examine whether teams collectively engage in unplanned, voluntary, and irrational delay of team tasks. Based on theory and research on self-regulation, team processes, and team motivation we developed a conceptual multilevel model of predictors and outcomes of team procrastination. In a sample of 209 student debating teams, we investigated whether and why teams engage in collective procrastination as a team, and what consequences team procrastination has in terms of team member well-being and team performance. The results supported the existence of team procrastination as a team-level construct that has some stability over time. The teams’ composition in terms of individual-level trait procrastination, as well as the teams’ motivational states (i.e., team learning goal orientation, team performance-approach goal orientation in interaction with team efficacy) predicted team procrastination. Team procrastination related positively to team members’ stress levels, especially for those low on trait procrastination. Furthermore, team procrastination had an indirect negative relationship with team performance, through teams’ collective stress levels. These findings add to the theoretical understanding of self-regulatory processes of teams, and highlight the practical importance of paying attention to team-level states and processes such as team goal orientation and team procrastination. PMID:29674991

  5. When Teams Fail to Self-Regulate: Predictors and Outcomes of Team Procrastination Among Debating Teams

    Directory of Open Access Journals (Sweden)

    Edwin A. J. Van Hooft

    2018-04-01

    Full Text Available Models of team development have indicated that teams typically engage in task delay during the first stages of the team’s life cycle. An important question is to what extent this equally applies to all teams, or whether there is variation across teams in the amount of task delay. The present study introduces the concept of team procrastination as a lens through which we can examine whether teams collectively engage in unplanned, voluntary, and irrational delay of team tasks. Based on theory and research on self-regulation, team processes, and team motivation we developed a conceptual multilevel model of predictors and outcomes of team procrastination. In a sample of 209 student debating teams, we investigated whether and why teams engage in collective procrastination as a team, and what consequences team procrastination has in terms of team member well-being and team performance. The results supported the existence of team procrastination as a team-level construct that has some stability over time. The teams’ composition in terms of individual-level trait procrastination, as well as the teams’ motivational states (i.e., team learning goal orientation, team performance-approach goal orientation in interaction with team efficacy predicted team procrastination. Team procrastination related positively to team members’ stress levels, especially for those low on trait procrastination. Furthermore, team procrastination had an indirect negative relationship with team performance, through teams’ collective stress levels. These findings add to the theoretical understanding of self-regulatory processes of teams, and highlight the practical importance of paying attention to team-level states and processes such as team goal orientation and team procrastination.

  6. Imaging and Manipulating Energy Transfer Among Quantum Dots at Individual Dot Resolution.

    Science.gov (United States)

    Nguyen, Duc; Nguyen, Huy A; Lyding, Joseph W; Gruebele, Martin

    2017-06-27

    Many processes of interest in quantum dots involve charge or energy transfer from one dot to another. Energy transfer in films of quantum dots as well as between linked quantum dots has been demonstrated by luminescence shift, and the ultrafast time-dependence of energy transfer processes has been resolved. Bandgap variation among dots (energy disorder) and dot separation are known to play an important role in how energy diffuses. Thus, it would be very useful if energy transfer could be visualized directly on a dot-by-dot basis among small clusters or within films of quantum dots. To that effect, we report single molecule optical absorption detected by scanning tunneling microscopy (SMA-STM) to image energy pooling from donor into acceptor dots on a dot-by-dot basis. We show that we can manipulate groups of quantum dots by pruning away the dominant acceptor dot, and switching the energy transfer path to a different acceptor dot. Our experimental data agrees well with a simple Monte Carlo lattice model of energy transfer, similar to models in the literature, in which excitation energy is transferred preferentially from dots with a larger bandgap to dots with a smaller bandgap.

  7. Leading Teams of Leaders: What Helps Team Member Learning?

    Science.gov (United States)

    Higgins, Monica; Young, Lissa; Weiner, Jennie; Wlodarczyk, Steven

    2010-01-01

    School districts are moving toward a new form of management in which superintendents need to form and nurture leadership teams. A study of 25 such teams in Connecticut suggests that a team's effectiveness is maximized when the team members are coached by other team members, not the superintendent, and when they are coached on task-related…

  8. Team Psychological Safety and Team Learning: A Cultural Perspective

    Science.gov (United States)

    Cauwelier, Peter; Ribière, Vincent M.; Bennet, Alex

    2016-01-01

    Purpose: The purpose of this paper was to evaluate if the concept of team psychological safety, a key driver of team learning and originally studied in the West, can be applied in teams from different national cultures. The model originally validated for teams in the West is applied to teams in Thailand to evaluate its validity, and the views team…

  9. Measuring Team Learning Behaviours through Observing Verbal Team Interaction

    Science.gov (United States)

    Raes, Elisabeth; Boon, Anne; Kyndt, Eva; Dochy, Filip

    2015-01-01

    Purpose: This study aims to explore, as an answer to the observed lack of knowledge about actual team learning behaviours, the characteristics of the actual observed basic team learning behaviours and facilitating team learning behaviours more in-depth of three project teams. Over time, team learning in an organisational context has been…

  10. Team Learning Beliefs and Behaviours in Response Teams

    Science.gov (United States)

    Boon, Anne; Raes, Elisabeth; Kyndt, Eva; Dochy, Filip

    2013-01-01

    Purpose: Teams, teamwork and team learning have been the subject of many research studies over the last decades. This article aims at investigating and confirming the Team Learning Beliefs and Behaviours (TLB&B) model within a very specific population, i.e. police and firemen teams. Within this context, the paper asks whether the team's…

  11. Groups Meet . . . Teams Improve: Building Teams That Learn

    Science.gov (United States)

    Hillier, Janet; Dunn-Jensen, Linda M.

    2013-01-01

    Although most business students participate in team-based projects during undergraduate or graduate course work, the team experience does not always teach team skills or capture the team members' potential: Students complete the task at hand but the explicit process of becoming a team is often not learned. Drawing from organizational learning…

  12. [Acute blue urticaria following subcutaneous injection of patent blue dye].

    Science.gov (United States)

    Hamelin, A; Vial-Dupuy, A; Lebrun-Vignes, B; Francès, C; Soria, A; Barete, S

    2015-11-01

    Patent blue (PB) is a lymphatic vessel dye commonly used in France for sentinel lymph node detection in breast cancer, and less frequently in melanoma, and which may induce hypersensitivity reactions. We report a case of acute blue urticaria occurring within minutes of PB injection. Ten minutes after PB injection for sentinel lymph node detection during breast cancer surgery, a 49-year-old woman developed generalised acute blue urticaria and eyelid angioedema without bronchospasm or haemodynamic disturbance, but requiring discontinuation of surgery. Skin testing using PB and the anaesthetics given were run 6 weeks after the episode and confirmed PB allergy. PB was formally contra-indicated. Immediate hypersensitivity reactions to PB have been reported for between 0.24 and 2.2% of procedures. Such reactions are on occasion severe, chiefly involving anaphylactic shock. Two mechanisms are probably associated: non-specific histamine release and/or an IgE-mediated mechanism. Skin tests are helpful in confirming the diagnosis of PB allergy. Blue acute urticaria is one of the clinical manifestations of immediate hypersensitivity reactions to patent blue dye. Skin tests must be performed 6 weeks after the reaction in order to confirm the diagnosis and formally contra-indicate this substance. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  13. Building the team for team science

    Science.gov (United States)

    Read, Emily K.; O'Rourke, M.; Hong, G. S.; Hanson, P. C.; Winslow, Luke A.; Crowley, S.; Brewer, C. A.; Weathers, K. C.

    2016-01-01

    The ability to effectively exchange information and develop trusting, collaborative relationships across disciplinary boundaries is essential for 21st century scientists charged with solving complex and large-scale societal and environmental challenges, yet these communication skills are rarely taught. Here, we describe an adaptable training program designed to increase the capacity of scientists to engage in information exchange and relationship development in team science settings. A pilot of the program, developed by a leader in ecological network science, the Global Lake Ecological Observatory Network (GLEON), indicates that the training program resulted in improvement in early career scientists’ confidence in team-based network science collaborations within and outside of the program. Fellows in the program navigated human-network challenges, expanded communication skills, and improved their ability to build professional relationships, all in the context of producing collaborative scientific outcomes. Here, we describe the rationale for key communication training elements and provide evidence that such training is effective in building essential team science skills.

  14. Blue Marble Eastern Hemisphere

    Science.gov (United States)

    2002-01-01

    Drawing on data from multiple satellite missions (not all collected at the same time), a team of NASA scientists and graphic artists created layers of global data for everything from the land surface, to polar sea ice, to the light reflected by the chlorophyll in the billions of microscopic plants that grow in the ocean. They wrapped these layers around a globe, set it against a black background, and simulated the hazy edge of the Earth's atmosphere (the limb) that appears in astronaut photography of the Earth. The land surface layer is based on photo-like surface reflectance observations (reflected sunlight) measured by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Terra satellite in July 2004. The sea ice layer near the poles comes from Terra MODIS observations of daytime sea ice observed between August 28 and September 6, 2001. The ocean layer is a composite. In shallow water areas, the layer shows surface reflectances observed by Terra MODIS in July 2004. In the open ocean, the photo-like layer is overlaid with observations of the average ocean chlorophyll content for 2004. NASA's Aqua MODIS collected the chlorophyll data. The cloud layer shows a single-day snapshot of clouds observed by Terra MODIS across the planet on July 29, 2001. City lights on Earth's night side are visualized from data collected by the Defense Meteorological Satellite Program mission between 1994-1995. The topography layer is based on radar data collected by the Space Shuttle Endeavour during an 11-day mission in February of 2000. Topography over Antarctica comes from the Radarsat Antarctic Mapping Project, version 2.

  15. Blue Marble Western Hemisphere

    Science.gov (United States)

    2002-01-01

    Drawing on data from multiple satellite missions (not all collected at the same time), a team of NASA scientists and graphic artists created layers of global data for everything from the land surface, to polar sea ice, to the light reflected by the chlorophyll in the billions of microscopic plants that grow in the ocean. They wrapped these layers around a globe, set it against a black background, and simulated the hazy edge of the Earth's atmosphere (the limb) that appears in astronaut photography of the Earth. The land surface layer is based on photo-like surface reflectance observations (reflected sunlight) measured by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Terra satellite in July 2004. The sea ice layer near the poles comes from Terra MODIS observations of daytime sea ice observed between August 28 and September 6, 2001. The ocean layer is a composite. In shallow water areas, the layer shows surface reflectances observed by Terra MODIS in July 2004. In the open ocean, the photo-like layer is overlaid with observations of the average ocean chlorophyll content for 2004. NASA's Aqua MODIS collected the chlorophyll data. The cloud layer shows a single-day snapshot of clouds observed by Terra MODIS across the planet on July 29, 2001. City lights on Earth's night side are visualized from data collected by the Defense Meteorological Satellite Program mission between 1994-1995. The topography layer is based on radar data collected by the Space Shuttle Endeavour during an 11-day mission in February of 2000. Topography over Antarctica comes from the Radarsat Antarctic Mapping Project, version 2.

  16. Next generation red teaming

    CERN Document Server

    Dalziel, Henry

    2015-01-01

    Red Teaming is can be described as a type of wargaming.In private business, penetration testers audit and test organization security, often in a secretive setting. The entire point of the Red Team is to see how weak or otherwise the organization's security posture is. This course is particularly suited to CISO's and CTO's that need to learn how to build a successful Red Team, as well as budding cyber security professionals who would like to learn more about the world of information security. Teaches readers how to dentify systemic security issues based on the analysis of vulnerability and con

  17. Project team motyvation

    OpenAIRE

    Jasionis, Dominykas

    2016-01-01

    The term paper is to analyze the formation of the team and its - motyvation, and interviews from four different companies and find out the leaders in terms of your team, and what principle he tries to motivate her. The Tasks of this paper is to review the organization formed by a team; investigate the promotion of employees in enterprises; The four firms interviewed; Assess how you can work in different organizations. Methods used To analyze the topic, I decided to interview four different co...

  18. Record Charge Carrier Diffusion Length in Colloidal Quantum Dot Solids via Mutual Dot-To-Dot Surface Passivation.

    Science.gov (United States)

    Carey, Graham H; Levina, Larissa; Comin, Riccardo; Voznyy, Oleksandr; Sargent, Edward H

    2015-06-03

    Through a combination of chemical and mutual dot-to-dot surface passivation, high-quality colloidal quantum dot solids are fabricated. The joint passivation techniques lead to a record diffusion length for colloidal quantum dots of 230 ± 20 nm. The technique is applied to create thick photovoltaic devices that exhibit high current density without losing fill factor. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Photoionization cross-section of donor impurity in spherical quantum dots under electric and intense laser fields

    International Nuclear Information System (INIS)

    Burileanu, L.M.

    2014-01-01

    Using a perturbative method we have investigated the behavior of the binding energy and photoionization cross-section of a donor impurity in spherical GaAs–GaAlAs quantum dots under the influence of electric and intense high-frequency laser fields. The dependencies of the binding energy and photoionization cross-section on electric and laser field strength, dot radius and impurity position were investigated. Our results show that the amplitude of photoionization cross-section grows with the dot radius increase and the peak of the cross-section blue shifts with the laser intensity increment. We have found that the binding energy is not a monotonically function of laser intensity: it decreases or increases depending on electric field regime. The studied effects are even more pronounced as the quantum dot radius is smaller. -- Highlights: • A photoionization cross-section study in quantum dots under laser and electric fields. • The photoionization cross-section peaks are red shifted by the electric field. • The photoionization cross-section peaks are blue shifted by the laser field. • The combined effects of applied fields strongly affect the binding energy

  20. Hearing Conservation Team

    Data.gov (United States)

    Federal Laboratory Consortium — The Hearing Conservation Team focuses on ways to identify the early stages of noise-induced damage to the human ear.Our current research involves the evaluation of...

  1. Forging Provincial Reconstruction Teams

    National Research Council Canada - National Science Library

    Honore, Russel L; Boslego, David V

    2007-01-01

    The Provincial Reconstruction Team (PRT) training mission completed by First U.S. Army in April 2006 was a joint Service effort to meet a requirement from the combatant commander to support goals in Afghanistan...

  2. Critical Care Team

    Science.gov (United States)

    ... often uphold the patient's wishes. The critical care nurse becomes an important part of decision-making with the patient, the family and the care team. A registered nurse (RN) who is certified in critical care is ...

  3. Integrated Transdisciplinary Teams.

    Science.gov (United States)

    Gallivan-Fenlon, Amanda

    1994-01-01

    This article reviews the use of transdisciplinary teaming and integrated therapy for young children with multiple disabilities. It presents examples and suggestions for implementation, in the areas of flexibility, Individualized Education Program development, and parent participation. (JDD)

  4. Submarine Medicine Team

    Data.gov (United States)

    Federal Laboratory Consortium — The Submarine Medicine Team conducts basic and applied research on biomedical aspects of submarine and diving environments. It focuses on ways to optimize the health...

  5. Virtual Project Teams

    DEFF Research Database (Denmark)

    Bjørn, Pernille

    technology in six real-life virtual teams, two in industry and four in education, applying interpretative research and action research methods. Two main lines of investigation are pursued: the first involves an examination of the organisational issues related to groupware adaptation in virtual project teams......, professional disciplines, time differences and technology. This thesis comprises a general introduction, referred to as the summary report, and seven research papers, which deal in detail with the results and findings of the empirical cases. The summary report provides a general introduction to the research......, while the second looks at the social context and practices of virtual project teams. Two of the key findings are 1) that the process of groupware adaptation by virtual project teams can be viewed as a process of expanding and aligning the technological frames of the participants, which includes mutual...

  6. Virtual team collaboration

    DEFF Research Database (Denmark)

    Bjørn, Pernille; Ngwenyama, Ojelanki

    2009-01-01

    Managing international teams with geographically distributed participants is a complex task. The risk of communication breakdowns increases due to cultural and organizational differences grounded in the geographical distribution of the participants. Such breakdowns indicate general misunderstandi...

  7. Media and Security Team

    Data.gov (United States)

    Federal Laboratory Consortium — The Media And Security Team led by Prof. Min Wu was established in Fall 2001 at University of Maryland, College Park. A number of research and education activities...

  8. PPB | Study Team

    Science.gov (United States)

    The Pleuropulmonary Blastoma (PPB) DICER1 Syndrome Study team is made up of researchers from the National Cancer Institute, Children¹s National Medical Center, the International Pleuropulmonary Blastoma Registry, and Washington University in St. Louis.

  9. Leading Strategic Leader Teams

    National Research Council Canada - National Science Library

    Burleson, Willard M

    2008-01-01

    .... Although only 1 to 2 percent of the Army's senior leaders will attain a command position of strategic leadership, they are assisted by others, not only by teams specifically designed and structured...

  10. Making Teamwork Work: Team Knowledge for Team Effectiveness.

    Science.gov (United States)

    Guchait, Priyanko; Lei, Puiwa; Tews, Michael J

    2016-01-01

    This study examined the impact of two types of team knowledge on team effectiveness. The study assessed the impact of taskwork knowledge and teamwork knowledge on team satisfaction and performance. A longitudinal study was conducted with 27 service-management teams involving 178 students in a real-life restaurant setting. Teamwork knowledge was found to impact both team outcomes. Furthermore, team learning behavior was found to mediate the relationships between teamwork knowledge and team outcomes. Educators and managers should therefore ensure these types of knowledge are developed in teams along with learning behavior for maximum effectiveness.

  11. Closed String Thermodynamics and a Blue Tensor Spectrum

    CERN Document Server

    Brandenberger, Robert H; Patil, Subodh P

    2014-01-01

    The BICEP-2 team has reported the detection of primordial cosmic microwave background B-mode polarization, with hints of a suppression of power at large angular scales relative to smaller scales. Provided that the B-mode polarization is due to primordial gravitational waves, this might imply a blue tilt of the primordial gravitational wave spectrum. Such a tilt would be incompatible with standard inflationary models, although it was predicted some years ago in the context of a mechanism that thermally generates the primordial perturbations through a Hagedorn phase of string cosmology. The purpose of this note is to encourage greater scrutiny of the data with priors informed by a model that is immediately falsifiable, but which \\textit{predicts} features that might be favoured by the data-- namely a blue tensor tilt with an induced and complimentary red tilt to the scalar spectrum, with a naturally large tensor to scalar ratio that relates to both.

  12. Teams make it work: how team work engagement mediates between social resources and performance in teams.

    Science.gov (United States)

    Torrente, Pedro; Salanova, Marisa; Llorens, Susana; Schaufeli, Wilmar B

    2012-02-01

    In this study we analyze the mediating role of team work engagement between team social resources (i.e., supportive team climate, coordination, teamwork), and team performance (i.e., in-role and extra-role performance) as predicted by the Job Demands-Resources Model. Aggregated data of 533 employees nested within 62 teams and 13 organizations were used, whereas team performance was assessed by supervisor ratings. Structural equation modeling revealed that, as expected, team work engagement plays a mediating role between social resources perceived at the team level and team performance as assessed by the supervisor.

  13. Localized surface plasmon and exciton interaction in silver-coated cadmium sulphide quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Ghosh, P.; Rustagi, K. C.; Vasa, P.; Singh, B. P., E-mail: bhanuprs@gmail.com [Department of Physics, Indian Institute of Technology Bombay, Mumbai- 400076 (India)

    2015-05-15

    Localized surface plasmon and exciton coupling has been investigated on colloidal solutions of silver-coated CdS nanoparticles (NPs), synthesized by gamma irradiation. Two broad photoluminescence (PL) bands (blue/red) corresponding to band to band and defect state transitions have been observed for the bare and coated samples. In case of bare CdS NPs, the intensity of the red PL peak is about ten times higher than the blue PL peak intensity. However, on coating the CdS NPs with silver, the peak intensity of the blue PL band gets enhanced and becomes equal to that of the red PL band. High-resolution transmission electron microscopic (HRTEM) images adequately demonstrate size distribution of these metal/semiconductor nanocomposites. UV-Vis absorption studies show quantum confinement effect in these semiconductor quantum dot (SQD) systems. Absorption spectrum of silver-coated SQDs shows signature of surface plasmon-exciton coupling which has been theoretically verified.

  14. When teams fail to self-regulate: Predictors and outcomes of team procrastination among debating teams

    NARCIS (Netherlands)

    E.A.J. van Hooft (Edwin); H. van Mierlo (Heleen)

    2018-01-01

    textabstractModels of team development have indicated that teams typically engage in task delay during the first stages of the team's life cycle. An important question is to what extent this equally applies to all teams, or whether there is variation across teams in the amount of task delay. The

  15. Crystalline liquids: the blue phases

    Science.gov (United States)

    Wright, David C.; Mermin, N. David

    1989-04-01

    The blue phases of cholesteric liquid crystals are liquids that exhibit orientational order characterized by crystallographic space-group symmetries. We present here a pedagogical introduction to the current understanding of the equilibrium structure of these phases accompanied by a general overview of major experimental results. Using the Ginzburg-Landau free energy appropriate to the system, we first discuss in detail the character and stability of the usual helical phase of cholesterics, showing that for certain parameter ranges the helical phase is unstable to the appearance of one or more blue phases. The two principal models for the blue phases are two limiting cases of the Ginzburg-Landau theory. We explore each limit and conclude with some general considerations of defects in both models and an exact minimization of the free energy in a curved three-dimensional space.

  16. A visible-light-driven composite photocatalyst of TiO2 nanotube arrays and graphene quantum dots

    Directory of Open Access Journals (Sweden)

    Donald K. L. Chan

    2014-05-01

    Full Text Available TiO2 nanotube arrays are well-known efficient UV-driven photocatalysts. The incorporation of graphene quantum dots could extend the photo-response of the nanotubes to the visible-light range. Graphene quantum dot-sensitized TiO2 nanotube arrays were synthesized by covalently coupling these two materials. The product was characterized by Fourier-transform infrared spectrometry (FTIR, scanning electron microscopy (SEM, transmission electron microscopy (TEM, X-ray diffraction (XRD, thermogravimetric analysis (TGA and UV–vis absorption spectroscopy. The product exhibited high photocatalytic performance in the photodegradation of methylene blue and enhanced photocurrent under visible light irradiation.

  17. Relationships among Team Trust, Team Cohesion, Team Satisfaction and Project Team Effectiveness as Perceived by Project Managers in Malaysia

    OpenAIRE

    Han-Ping Fung

    2014-01-01

    Today, more and more project teams are formed to achieve organizational objectives as organizations generally recognized the importance and benefits of project teams. There is a compelling reason to study what are the team outcome factors that can predict project team effectiveness as it is unclear whether these team outcome factors can yield the same result in project setting whereby there is resource and time constraint compare to normal work teams which are ongoing and operational in natur...

  18. The Return of the Blue Butterfly

    Science.gov (United States)

    Santos, Anabela

    2014-05-01

    The Return of the Blue Butterfly The English writer Charles Dickens once wrote: "I only ask to be free. The butterflies are free". But are they really? The work that I performed with a group of students from 8th grade, had a starting point of climate change and the implications it has on ecosystems. Joining the passion I have for butterflies, I realized that they are also in danger of extinction due to these climatic effects. Thus, it was easy to seduce my students wanting to know more. Luckily I found Dr. Paula Seixas Arnaldo, a researcher at the University of Trás-os-Montes and Alto Douro, who has worked on butterflies and precisely investigated this issue. Portugal is the southern limit of butterfly-blue (Phengaris alcon), and has been many years in the red book of endangered species. Butterfly-blue is very demanding of their habitat, and disappears very easily if ideal conditions are not satisfied. Increased fragmentation of landscapes and degradation of suitable habitats, are considered the greatest challenges of the conservation of Phengaris butterfly in Portugal. In recent decades, climate change has also changed butterfly-blue spatial distribution with a movement of the species northward to colder locations, and dispersion in latitude. Butterflies of Europe must escape to the North because of the heat. Dr. Paula Seixas Arnaldo and her research team began a project, completed in December 2013, wanted to preserve and restore priority habitats recognized by the European Union to help species in danger of disappearing with increasing temperature. The blue butterfly is extremely important because it is a key indicator of the quality of these habitats. In the field, the butterflies are monitored to collect all possible data in order to identify the key species. Butterflies start flying in early July and cease in late August. Mating takes about an hour and occurs in the first days of life. The gentian-peat (Gentiana pneumonanthe) serves as the host plant for

  19. The Research of Self-Management Team and Superior-Direction Team in Team Learning Influential Factors

    OpenAIRE

    Zhang Wei

    2013-01-01

    Team learning is a cure for bureaucracy; it facilitates team innovation and team performance. But team learning occurs only when necessary conditions were met. This research focused on differences of team learning influential factors between self-management team and superior-direction team. Four variables were chosen as predictors of team learning though literature review and pilot interview. The 4 variables are team motivation, team trust, team conflict and team leadership. Selected 54 self ...

  20. Origin of faint blue stars

    International Nuclear Information System (INIS)

    Tutukov, A.; Iungelson, L.

    1987-01-01

    The origin of field faint blue stars that are placed in the HR diagram to the left of the main sequence is discussed. These include degenerate dwarfs and O and B subdwarfs. Degenerate dwarfs belong to two main populations with helium and carbon-oxygen cores. The majority of the hot subdwarfs most possibly are helium nondegenerate stars that are produced by mass exchange close binaries of moderate mass cores (3-15 solar masses). The theoretical estimates of the numbers of faint blue stars of different types brighter than certain stellar magnitudes agree with star counts based on the Palomar Green Survey. 28 references

  1. Spin storage in quantum dot ensembles and single quantum dots

    International Nuclear Information System (INIS)

    Heiss, Dominik

    2009-01-01

    This thesis deals with the investigation of spin relaxation of electrons and holes in small ensembles of self-assembled quantum dots using optical techniques. Furthermore, a method to detect the spin orientation in a single quantum dot was developed in the framework of this thesis. A spin storage device was used to optically generate oriented electron spins in small frequency selected quantum dot ensembles using circularly polarized optical excitation. The spin orientation can be determined by the polarization of the time delayed electroluminescence signal generated by the device after a continuously variable storage time. The degree of spin polarized initialization was found to be limited to 0.6 at high magnetic fields, where anisotropic effects are compensated. The spin relaxation was directly measured as a function of magnetic field, lattice temperature and s-shell transition energy of the quantum dot by varying the spin storage time up to 30 ms. Very long spin lifetimes are obtained with a lower limit of T 1 =20 ms at B=4 T and T=1 K. A strong magnetic field dependence T 1 ∝B -5 has been observed for low temperatures of T=1 K which weakens as the temperature is increased. In addition, the temperature dependence has been determined with T 1 ∝T -1 . The characteristic dependencies on magnetic field and temperature lead to the identification of the spin relaxation mechanism, which is governed by spin-orbit coupling and mediated by single phonon scattering. This finding is qualitatively supported by the energy dependent measurements. The investigations were extended to a modified device design that enabled studying the spin relaxation dynamics of heavy holes in self-assembled quantum dots. The measurements show a polarization memory effect for holes with up to 0.1 degree of polarization. Furthermore, investigations of the time dynamics of the hole spin relaxation reveal surprisingly long lifetimes T 1 h in the microsecond range, therefore, comparable with

  2. Spin storage in quantum dot ensembles and single quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Heiss, Dominik

    2009-10-15

    This thesis deals with the investigation of spin relaxation of electrons and holes in small ensembles of self-assembled quantum dots using optical techniques. Furthermore, a method to detect the spin orientation in a single quantum dot was developed in the framework of this thesis. A spin storage device was used to optically generate oriented electron spins in small frequency selected quantum dot ensembles using circularly polarized optical excitation. The spin orientation can be determined by the polarization of the time delayed electroluminescence signal generated by the device after a continuously variable storage time. The degree of spin polarized initialization was found to be limited to 0.6 at high magnetic fields, where anisotropic effects are compensated. The spin relaxation was directly measured as a function of magnetic field, lattice temperature and s-shell transition energy of the quantum dot by varying the spin storage time up to 30 ms. Very long spin lifetimes are obtained with a lower limit of T{sub 1}=20 ms at B=4 T and T=1 K. A strong magnetic field dependence T{sub 1}{proportional_to}B{sup -5} has been observed for low temperatures of T=1 K which weakens as the temperature is increased. In addition, the temperature dependence has been determined with T{sub 1}{proportional_to}T{sup -1}. The characteristic dependencies on magnetic field and temperature lead to the identification of the spin relaxation mechanism, which is governed by spin-orbit coupling and mediated by single phonon scattering. This finding is qualitatively supported by the energy dependent measurements. The investigations were extended to a modified device design that enabled studying the spin relaxation dynamics of heavy holes in self-assembled quantum dots. The measurements show a polarization memory effect for holes with up to 0.1 degree of polarization. Furthermore, investigations of the time dynamics of the hole spin relaxation reveal surprisingly long lifetimes T{sub 1}{sup h

  3. The Relationship between Management Team Size and Team Performance: The Mediating Effect of Team Psychological Safety

    OpenAIRE

    Midthaug, Mari Bratterud

    2017-01-01

    The purpose of this thesis is to explore the relationship between team size (number of team members) and team performance in management teams. There is a lack of empirical research exploring the potential links between these two elements within management teams. Further, little attention has been paid to potential mechanisms affecting this relationship. In this study, team psychological safety has been examined as a potential mediator in the size-performance relationship, hypothesizing that t...

  4. Team skills training

    International Nuclear Information System (INIS)

    Coe, R.P.; Carl, D.R.

    1991-01-01

    Numerous reports and articles have been written recently on the importance of team skills training for nuclear reactor operators, but little has appeared on the practical application of this theoretical guidance. This paper describes the activities of the Training and Education Department at GPU Nuclear (GPUN). In 1987, GPUN undertook a significant initiative in its licensed operator training programs to design and develop initial and requalification team skills training. Prior to that time, human interaction skills training (communication, stress management, supervisory skills, etc.) focused more on the individual rather than a group. Today, GPU Nuclear conducts team training at both its Three Mile Island (YMI), PA and Oyster Creek (OC), NJ generating stations. Videotaped feedback is sued extensively to critique and reinforce targeted behaviors. In fact, the TMI simulator trainer has a built-in, four camera system specifically designed for team training. Evaluations conducted on this training indicated these newly acquired skills are being carried over to the work environment. Team training is now an important and on-going part of GPUN operator training

  5. Science and Team Development

    Directory of Open Access Journals (Sweden)

    Bryan R. Cole

    2006-07-01

    Full Text Available This paper explores a new idea about the future development of science and teams, and predicts its possible applications in science, education, workforce development and research. The inter-relatedness of science and teamwork developments suggests a growing importance of team facilitators’ quality, as well as the criticality of detailed studies of teamwork processes and team consortiums to address the increasing complexity of exponential knowledge growth and work interdependency. In the future, it will become much easier to produce a highly specialised workforce, such as brain surgeons or genome engineers, than to identify, educate and develop individuals capable of the delicate and complex work of multi-team facilitation. Such individuals will become the new scientists of the millennium, having extraordinary knowledge in variety of scientific fields, unusual mix of abilities, possessing highly developed interpersonal and teamwork skills, and visionary ideas in illuminating bold strategies for new scientific discoveries. The new scientists of the millennium, through team consortium facilitation, will be able to build bridges between the multitude of diverse and extremely specialised knowledge and interdependent functions to improve systems for the further benefit of mankind.

  6. Quantum optics with single quantum dot devices

    International Nuclear Information System (INIS)

    Zwiller, Valery; Aichele, Thomas; Benson, Oliver

    2004-01-01

    A single radiative transition in a single-quantum emitter results in the emission of a single photon. Single quantum dots are single-quantum emitters with all the requirements to generate single photons at visible and near-infrared wavelengths. It is also possible to generate more than single photons with single quantum dots. In this paper we show that single quantum dots can be used to generate non-classical states of light, from single photons to photon triplets. Advanced solid state structures can be fabricated with single quantum dots as their active region. We also show results obtained on devices based on single quantum dots

  7. Large quantum dots with small oscillator strength

    DEFF Research Database (Denmark)

    Stobbe, Søren; Schlereth, T.W.; Höfling, S.

    2010-01-01

    We have measured the oscillator strength and quantum efficiency of excitons confined in large InGaAs quantum dots by recording the spontaneous emission decay rate while systematically varying the distance between the quantum dots and a semiconductor-air interface. The size of the quantum dots...... is measured by in-plane transmission electron microscopy and we find average in-plane diameters of 40 nm. We have calculated the oscillator strength of excitons of that size assuming a quantum-dot confinement given by a parabolic in-plane potential and a hard-wall vertical potential and predict a very large...... intermixing inside the quantum dots....

  8. The interaction between d-dot's

    International Nuclear Information System (INIS)

    Hirayama, Masaki; Machida, Masahiko; Koyama, Tomio; Ishida, Takekazu; Kato, Masaru

    2005-01-01

    We investigated the interaction between two square d-dot's. The d-dot is the nano-scaled superconducting composite structure that is made of a d-wave superconducting dot embedded in the s-wave superconducting matrix. In the numerical calculation, using the finite element method, we solved the two-components Ginzburg-Landau equation self-consistently. We obtained two kinds of solutions, which can be considered as ferromagnetic and antiferromagnetic configurations, when two d-dot's are separated parallel and diagonally. Also we discuss the applicability of d-dot's as an artificial spin system where the interactions can be controlled by the fabrication

  9. Increasing Student-Learning Team Effectiveness with Team Charters

    Science.gov (United States)

    Hunsaker, Phillip; Pavett, Cynthia; Hunsaker, Johanna

    2011-01-01

    Because teams are a ubiquitous part of most organizations today, it is common for business educators to use team assignments to help students experientially learn about course concepts and team process. Unfortunately, students frequently experience a number of problems during team assignments. The authors describe the results of their research and…

  10. Blue Ocean vs. Five Forces

    NARCIS (Netherlands)

    A.E. Burke (Andrew); A.J. van Stel (André); A.R. Thurik (Roy)

    2010-01-01

    textabstractThe article reports on the authors' research in the Netherlands which focused on a profit model in Dutch retail stores and a so-called blue-ocean approach which requires a new market that attracts consumers and increases profits. Topics include the competitive strategy approach to

  11. Nuclear Spins in Quantum Dots

    NARCIS (Netherlands)

    Erlingsson, S.I.

    2003-01-01

    The main theme of this thesis is the hyperfine interaction between the many lattice nuclear spins and electron spins localized in GaAs quantum dots. This interaction is an intrinsic property of the material. Despite the fact that this interaction is rather weak, it can, as shown in this thesis,

  12. Luminescent Surface Quaternized Carbon Dots

    KAUST Repository

    Bourlinos, Athanasios B.; Zbořil, Radek; Petr, Jan; Bakandritsos, Aristides; Krysmann, Marta; Giannelis, Emmanuel P.

    2012-01-01

    Thermal oxidation of a salt precursor made from the acid base combination of tris(hydroxymethyl)aminomethane and betaine hydrochloride results in light-emitting surface quaternized carbon dots that are water-dispersible, display anion exchange properties, and exhibit uniform size/surface charge. © 2011 American Chemical Society.

  13. Luminescent Surface Quaternized Carbon Dots

    KAUST Repository

    Bourlinos, Athanasios B.

    2012-01-10

    Thermal oxidation of a salt precursor made from the acid base combination of tris(hydroxymethyl)aminomethane and betaine hydrochloride results in light-emitting surface quaternized carbon dots that are water-dispersible, display anion exchange properties, and exhibit uniform size/surface charge. © 2011 American Chemical Society.

  14. DOT strategies versus orbiter strategies

    NARCIS (Netherlands)

    Rutten, R.J.

    2001-01-01

    The Dutch Open Telescope is a high-resolution solar imager coming on-line at La Palma. The definition of the DOT science niche, strategies, and requirements resemble Solar Orbiter considerations and deliberations. I discuss the latter in the light of the former, and claim that multi-line observation

  15. Polymer-coated quantum dots

    NARCIS (Netherlands)

    Tomczak, N.; Liu, Rongrong; Vancso, Gyula J.

    2013-01-01

    Quantum Dots (QDs) are semiconductor nanocrystals with distinct photophysical properties finding applications in biology, biosensing, and optoelectronics. Polymeric coatings of QDs are used primarily to provide long-term colloidal stability to QDs dispersed in solutions and also as a source of

  16. Hyperdense dots mimicking microcalcifications : Mammographic findings

    International Nuclear Information System (INIS)

    Kim, Nam Hyeon; Park, Jeong Mi; Goo, Hyun Woo; Bang, Sun Woo

    1996-01-01

    To differentiate fine hyperdense dots mimicking microcalcifications from true microcalcifications on mammography. Mammograms showing hyperdense dots in ten patients (mean age, 59 years) were evaluated. Two radiologists were asked to differentiate with the naked eye the hyperdense dots seen on ten mammograms and proven microcalcifications seen on ten mammograms. Densitometry was also performed for all lesions and the contrast index was calculated. The shape and distribution of the hyperdense dots were evaluated and enquires were made regarding any history of breast disease and corresponding treatment. Biopsies were performed for two patients with hyperdense dots. Two radiologists made correct diagnoses in 19/20 cases(95%). The contrast index was 0.10-0.88 (mean 0.58) for hyperdense dots and 0.02-0.45 (mean 0.17) for true microcalcifications. The hyperdense dots were finer and homogeneously rounder than the microcalcifications. Distribution of the hyperdense dots was more superficial in subcutaneous fat (seven cases) and subareolar area (six cases). All ten patients with hyperdense dots had history of mastitis and abscesses and had been treated by open drainage (six cases) and/or folk remedy (four cases). In eight patients, herb patches had been attached. Biopsies of hyperdense dots did not show any microcalcification or evidence of malignancy. These hyperdense dots were seen mainly in older patients. Their characteristic density, shape, distribution and clinical history makes differential diagnosis from true microcalcifications easy and could reduce unnecessary diagnostic procedures such as surgical biopsy

  17. Hyperdense dots mimicking microcalcifications : Mammographic findings

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Nam Hyeon; Park, Jeong Mi; Goo, Hyun Woo; Bang, Sun Woo [Asan Medical Center, University of Ulsan College of Medicine, Seoul (Korea, Republic of)

    1996-12-01

    To differentiate fine hyperdense dots mimicking microcalcifications from true microcalcifications on mammography. Mammograms showing hyperdense dots in ten patients (mean age, 59 years) were evaluated. Two radiologists were asked to differentiate with the naked eye the hyperdense dots seen on ten mammograms and proven microcalcifications seen on ten mammograms. Densitometry was also performed for all lesions and the contrast index was calculated. The shape and distribution of the hyperdense dots were evaluated and enquires were made regarding any history of breast disease and corresponding treatment. Biopsies were performed for two patients with hyperdense dots. Two radiologists made correct diagnoses in 19/20 cases(95%). The contrast index was 0.10-0.88 (mean 0.58) for hyperdense dots and 0.02-0.45 (mean 0.17) for true microcalcifications. The hyperdense dots were finer and homogeneously rounder than the microcalcifications. Distribution of the hyperdense dots was more superficial in subcutaneous fat (seven cases) and subareolar area (six cases). All ten patients with hyperdense dots had history of mastitis and abscesses and had been treated by open drainage (six cases) and/or folk remedy (four cases). In eight patients, herb patches had been attached. Biopsies of hyperdense dots did not show any microcalcification or evidence of malignancy. These hyperdense dots were seen mainly in older patients. Their characteristic density, shape, distribution and clinical history makes differential diagnosis from true microcalcifications easy and could reduce unnecessary diagnostic procedures such as surgical biopsy.

  18. When Teams Go Crazy

    DEFF Research Database (Denmark)

    Kuhrmann, Marco; Münch, Jürgen

    2016-01-01

    Software development consists to a large extend of human-based processes with continuously increasing demands regarding interdisciplinary team work. Understanding the dynamics of software teams can be seen as highly important to successful project execution. Hence, for future project managers......, knowledge about non-technical processes in teams is significant. In this paper, we present a course unit that provides an environment in which students can learn and experience the impact of group dynamics on project performance and quality. The course unit uses the Tuckman model as theoretical framework......, and borrows from controlled experiments to organize and implement its practical parts in which students then experience the effects of, e.g., time pressure, resource bottlenecks, staff turnover, loss of key personnel, and other stress factors. We provide a detailed design of the course unit to allow...

  19. Creativity and Creative Teams

    Science.gov (United States)

    Wood, Richard M.; Bauer, Steven X. S.; Hunter, Craig A.

    2001-01-01

    A review of the linkage between knowledge, creativity, and design is presented and related to the best practices of multidisciplinary design teams. The discussion related to design and design teams is presented in the context of both the complete aerodynamic design community and specifically the work environment at the NASA Langley Research Center. To explore ways to introduce knowledge and creativity into the research and design environment at NASA Langley Research Center a creative design activity was executed within the context of a national product development activity. The success of the creative design team activity gave rise to a need to communicate the experience in a straightforward and managed approach. As a result the concept of creative potential its formulated and assessed with a survey of a small portion of the aeronautics research staff at NASA Langley Research Center. The final section of the paper provides recommendations for future creative organizations and work environments.

  20. Team Leadership: Leadership Role Achievement in Supervision Teams in Turkey

    OpenAIRE

    Ali Sabanci; Izzet Ozdemir

    2015-01-01

    The purpose of this paper is to explore the views of team leaders and team members of supervision teams about the extent that team leaders achieve their team leadership roles in Turkey. This research was conducted as a survey. The population of the study consisted of approximately 2650 supervisors (inspectors) working in 81 provinces distributed to seven geographical regions in Turkey. The sample consisted of 563 supervisors which were selected out by random sampling. The data were gathered b...

  1. Beautiful Teams Inspiring and Cautionary Tales from Veteran Team Leaders

    CERN Document Server

    Stellman, Andrew

    2009-01-01

    What's it like to work on a great software development team facing an impossible problem? How do you build an effective team? Beautiful Teams takes you behind the scenes with some of the most interesting teams in software engineering history. You'll learn from veteran team leaders' successes and failures, told through a series of engaging personal stories -- and interviews -- by leading programmers, architects, project managers, and thought leaders.

  2. Modeling of the quantum dot filling and the dark current of quantum dot infrared photodetectors

    International Nuclear Information System (INIS)

    Ameen, Tarek A.; El-Batawy, Yasser M.; Abouelsaood, A. A.

    2014-01-01

    A generalized drift-diffusion model for the calculation of both the quantum dot filling profile and the dark current of quantum dot infrared photodetectors is proposed. The confined electrons inside the quantum dots produce a space-charge potential barrier between the two contacts, which controls the quantum dot filling and limits the dark current in the device. The results of the model reasonably agree with a published experimental work. It is found that increasing either the doping level or the temperature results in an exponential increase of the dark current. The quantum dot filling turns out to be nonuniform, with a dot near the contacts containing more electrons than one in the middle of the device where the dot occupation approximately equals the number of doping atoms per dot, which means that quantum dots away from contacts will be nearly unoccupied if the active region is undoped

  3. SPQR Team Description Paper

    OpenAIRE

    Cherubini , Andrea; Leonetti , M; Marchetti , L; De Luca , A; Iocchi , L; Nardi , D; Oriolo , G; Vendittelli , M

    2008-01-01

    International audience; SPQR is the group of the Faculty of Engineering at Sapienza University of Rome in Italy, that is involved in RoboCup competitions since 1998 in different leagues (Middle-size 1998-2002, Four-legged since 2000, Real-rescue-robots 2003-2006, Virtual-rescue since 2006 and @Home in 2006). In RoboCup 2008, SPQR team will participate in the Standard Platform League with Nao humanoid robots and in the Virtual Rescue League.The team for 2008 is composed by two groups from the C...

  4. Autonomous mobile robot teams

    Science.gov (United States)

    Agah, Arvin; Bekey, George A.

    1994-01-01

    This paper describes autonomous mobile robot teams performing tasks in unstructured environments. The behavior and the intelligence of the group is distributed, and the system does not include a central command base or leader. The novel concept of the Tropism-Based Cognitive Architecture is introduced, which is used by the robots in order to produce behavior transforming their sensory information to proper action. The results of a number of simulation experiments are presented. These experiments include worlds where the robot teams must locate, decompose, and gather objects, and defend themselves against hostile predators, while navigating around stationary and mobile obstacles.

  5. Multi-Color Single Particle Tracking with Quantum Dots

    DEFF Research Database (Denmark)

    Christensen, Eva Arnspang; Brewer, J. R.; Lagerholm, B. C.

    2012-01-01

    . multiplex single molecule sensitivity applications such as single particle tracking (SPT). In order to fully optimize single molecule multiplex application with QDs, we have in this work performed a comprehensive quantitative investigation of the fluorescence intensities, fluorescence intensity fluctuations......Quantum dots (QDs) have long promised to revolutionize fluorescence detection to include even applications requiring simultaneous multi-species detection at single molecule sensitivity. Despite the early promise, the unique optical properties of QDs have not yet been fully exploited in e. g...... further show that there is only a small size advantage in using blue-shifted QDs in biological applications because of the additional size of the water-stabilizing surface coat. Extending previous work, we finally also show that parallel four color multicolor (MC)-SPT with QDs is possible at an image...

  6. Eco-friendly intracellular biosynthesis of CdS quantum dots without changing Escherichia coli's antibiotic resistance.

    Science.gov (United States)

    Yan, Zheng-Yu; Du, Qing-Qing; Qian, Jing; Wan, Dong-Yu; Wu, Sheng-Mei

    2017-01-01

    In the paper, a green and efficient biosynthetical technique was reported for preparing cadmium sulfide (CdS) quantum dots, in which Escherichia coli (E. coli) was chosen as a biomatrix. Fluorescence emission spectra and fluorescent microscopic photographs revealed that as-produced CdS quantum dots had an optimum fluorescence emission peak located at 470nm and emitted a blue-green fluorescence under ultraviolet excitation. After extracted from bacterial cells and located the nanocrystals' foci in vivo, the CdS quantum dots showed a uniform size distribution by transmission electron microscope. Through the systematical investigation of the biosynthetic conditions, including culture medium replacement, input time point of cadmium source, working concentrations of raw inorganic ions, and co-cultured time spans of bacteria and metal ions in the bio-manufacture, the results revealed that CdS quantum dots with the strongest fluorescence emission were successfully prepared when E. coli cells were in stationary phase, with the replacement of culture medium and following the incubation with 1.0×10 -3 mol/L cadmium source for 2 days. Results of antimicrobial susceptibility testing indicated that the sensitivities to eight types of antibiotics of E. coli were barely changed before and after CdS quantum dots were prepared in the mild temperature environment, though a slight fall of antibiotic resistance could be observed, suggesting hinted the proposed technique of producing quantum dots is a promising environmentally low-risk protocol. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. A highly selective fluorescence sensing platform for nanomolar Hg(II) detection based on cytosine derived quantum dot

    Science.gov (United States)

    Luo, Liang; Song, Ting; Wang, Haoqiang; Yuan, Qunhui; Zhou, Shenghai

    2018-03-01

    Inspired by low toxicity and good biocompatibility of biomass derived quantum dot (QD), we herein developed a cytosine derived quantum dot, namely cyt-dot, via a one-step hydrothermal synthesis. The as-prepared cyt-dot emits blue fluorescence (FL) containing abundant oxygen (20.6 at.%) and nitrogen (24.1 at.%) contents. The cyt-dot based sensing platform shows exclusive selectivity for Hg(II) while being insensitive towards Fe(III) and Ag(I), which are important interference that usually cannot be ruled out. The detection limit for Hg(II) is of 11 nM, which is very close to the guideline value of 10 nM allowed by the U.S. Environmental Protection Agency in drinking water. In real water sample analyses, the present sensing platform can fulfil satisfied recoveries ranging from 100% to 108%. Besides, the acidity of solution has almost no effect on the sensing performance of the cyt-dot in a pH range of 5-8, suggesting its potential applications in sensing and bio-imaging.

  8. Predictors of Team Work Satisfaction

    Science.gov (United States)

    Hamlyn-Harris, James H.; Hurst, Barbara J.; von Baggo, Karola; Bayley, Anthony J.

    2006-01-01

    The ability to work in teams is an attribute highly valued by employers of information technology (IT) graduates. For IT students to effectively engage in team work tasks, the process of working in teams should be satisfying for the students. This work explored whether university students who were involved in compulsory team work were satisfied…

  9. Quadra-quantum Dots and Related Patterns of Quantum Dot Molecules:

    Directory of Open Access Journals (Sweden)

    Somsak Panyakeow

    2010-10-01

    Full Text Available Abstract Laterally close-packed quantum dots (QDs called quantum dot molecules (QDMs are grown by modified molecular beam epitaxy (MBE. Quantum dots could be aligned and cross hatched. Quantum rings (QRs created from quantum dot transformation during thin or partial capping are used as templates for the formations of bi-quantum dot molecules (Bi-QDMs and quantum dot rings (QDRs. Preferable quantum dot nanostructure for quantum computation based on quantum dot cellular automata (QCA is laterally close-packed quantum dot molecules having four quantum dots at the corners of square configuration. These four quantum dot sets are called quadra-quantum dots (QQDs. Aligned quadra-quantum dots with two electron confinements work like a wire for digital information transmission by Coulomb repulsion force, which is fast and consumes little power. Combination of quadra-quantum dots in line and their cross-over works as logic gates and memory bits. Molecular Beam Epitaxial growth technique called ‘‘Droplet Epitaxy” has been developed for several quantum nanostructures such as quantum rings and quantum dot rings. Quantum rings are prepared by using 20 ML In-Ga (15:85 droplets deposited on a GaAs substrate at 390°C with a droplet growth rate of 1ML/s. Arsenic flux (7–8×10-6Torr is then exposed for InGaAs crystallization at 200°C for 5 min. During droplet epitaxy at a high droplet thickness and high temperature, out-diffusion from the centre of droplets occurs under anisotropic strain. This leads to quantum ring structures having non-uniform ring stripes and deep square-shaped nanoholes. Using these peculiar quantum rings as templates, four quantum dots situated at the corners of a square shape are regrown. Two of these four quantum dots are aligned either or , which are preferable crystallographic directions of quantum dot alignment in general.

  10. Ability Dispersion and Team Performance

    DEFF Research Database (Denmark)

    Hoogendoorn, Sander; Parker, Simon C.; Van Praag, Mirjam

    What is the effect of dispersed levels of cognitive ability of members of a (business) team on their team's performance? This paper reports the results of a field experiment in which 573 students in 49 (student) teams start up and manage real companies under identical circumstances for one year. We...... ensured exogenous variation in otherwise random team composition by assigning students to teams based on their measured cognitive abilities. Each team performs a variety of tasks, often involving complex decision making. The key result of the experiment is that the performance of business teams first...... increases and then decreases with ability dispersion. We seek to understand this finding by developing a model in which team members of different ability levels form sub- teams with other team members with similar ability levels to specialize in different productive tasks. Diversity spreads production over...

  11. Si quantum dot structures and their applications

    Science.gov (United States)

    Shcherbyna, L.; Torchynska, T.

    2013-06-01

    This paper presents briefly the history of emission study in Si quantum dots (QDs) in the last two decades. Stable light emission of Si QDs and NCs was observed in the spectral ranges: blue, green, orange, red and infrared. These PL bands were attributed to the exciton recombination in Si QDs, to the carrier recombination through defects inside of Si NCs or via oxide related defects at the Si/SiOx interface. The analysis of recombination transitions and the different ways of the emission stimulation in Si QD structures, related to the element variation for the passivation of surface dangling bonds, as well as the plasmon induced emission and rare earth impurity activation, have been presented. The different applications of Si QD structures in quantum electronics, such as: Si QD light emitting diodes, Si QD single union and tandem solar cells, Si QD memory structures, Si QD based one electron devices and double QD structures for spintronics, have been discussed as well. Note the significant worldwide interest directed toward the silicon-based light emission for integrated optoelectronics is related to the complementary metal-oxide semiconductor compatibility and the possibility to be monolithically integrated with very large scale integrated (VLSI) circuits. The different features of poly-, micro- and nanocrystalline silicon for solar cells, that is a mixture of both amorphous and crystalline phases, such as the silicon NCs or QDs embedded in a α-Si:H matrix, as well as the thin film 2-cell or 3-cell tandem solar cells based on Si QD structures have been discussed as well. Silicon NC based structures for non-volatile memory purposes, the recent studies of Si QD base single electron devices and the single electron occupation of QDs as an important component to the measurement and manipulation of spins in quantum information processing have been analyzed as well.

  12. Affirmative action and team performance

    OpenAIRE

    Kölle, Felix

    2016-01-01

    We experimentally investigate spillover effects of affirmative action policies in tournaments on subsequent team performance and the willingness to work in teams. In three different team environments, we find that such policies in form of gender quotas do not harm performance and cooperation within teams, and do not weaken people's willingness to work in teams. Our results, thus, provide further evidence that gender quotas can have the desired effect of promoting women without harming efficie...

  13. AA magnet measurement team

    CERN Multimedia

    CERN PhotoLab

    1978-01-01

    Quickly improvised measurement equipment for the AA (Antiproton Accumulator) was all the tight schedule permitted, but the high motivation of the team made up for the lack of convenience. From left to right: Roy Billinge (Joint AA Project Leader, the other one was Simon van der Meer); Bruno Autin, Brian Pincott, Colin Johnson.

  14. Materials Technical Team Roadmap

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2013-08-01

    Roadmap identifying the efforts of the Materials Technical Team (MTT) to focus primarily on reducing the mass of structural systems such as the body and chassis in light-duty vehicles (including passenger cars and light trucks) which enables improved vehicle efficiency regardless of the vehicle size or propulsion system employed.

  15. Aircrew team management program

    Science.gov (United States)

    Margerison, Charles; Mccann, Dick; Davies, Rod

    1987-01-01

    The key features of the Aircrew Team Management Workshop which was designed for and in consultation with Trans Australia Airlines are outlined. Five major sections are presented dealing with: (1) A profile of the airline and the designers; (2) Aircrew consultation and involvement; (3) Educational design and development; (4) Implementation and instruction; and (5) Evaluation and assessment. These areas are detailed.

  16. The Team We Got.

    Science.gov (United States)

    Soos, Frank

    1992-01-01

    Discusses the importance of high school basketball in rural West Virginia and what it felt like to win and to lose. Reflects on how playing team sports builds character, and suggests that, although life goes on regardless of game outcomes, it is still difficult to think of high school basketball as just a game. (LP)

  17. Web Team Development

    Science.gov (United States)

    Church, Jennifer; Felker, Kyle

    2005-01-01

    The dynamic world of the Web has provided libraries with a wealth of opportunities, including new approaches to the provision of information and varied internal staffing structures. The development of self-managed Web teams, endowed with authority and resources, can create an adaptable and responsive culture within libraries. This new working team…

  18. National Response Team

    Science.gov (United States)

    Response planning and coordination (not direct response itself) is accomplished at the federal level through the U.S. National Response Team (NRT), an interagency group co-chaired by EPA and U.S. Coast Guard. NRT distributes information, plans, and trains.

  19. Multidisciplinary team functioning.

    Science.gov (United States)

    Kovitz, K E; Dougan, P; Riese, R; Brummitt, J R

    1984-01-01

    This paper advocates the need to move beyond interdisciplinary team composition as a minimum criterion for multidisciplinary functioning in child abuse treatment. Recent developments within the field reflect the practice of shared professional responsibility for detection, case management and treatment. Adherence to this particular model for intervention requires cooperative service planning and implementation as task related functions. Implicitly, this model also carries the potential to incorporate the supportive functioning essential to effective group process. However, explicit attention to the dynamics and process of small groups has been neglected in prescriptive accounts of multidisciplinary child abuse team organization. The present paper therefore focuses upon the maintenance and enhancement aspects of multidisciplinary group functioning. First, the development and philosophy of service for the Alberta Children's Hospital Child Abuse Program are reviewed. Second, composition of the team, it's mandate for service, and the population it serves are briefly described. Third, the conceptual framework within which the program functions is outlined. Strategies for effective group functioning are presented and the difficulties encountered with this model are highlighted. Finally, recommendations are offered for planning and implementing a multidisciplinary child abuse team and for maintaining its effective group functioning.

  20. The CHIK Team

    Indian Academy of Sciences (India)

    The CHIK Team. Arankalle VA, Mishra AC. Tandale BV Clinical. Yergolkar P, Sudeep Balan Virus Isolations. Cherian S, Walimbe A Bioinformatics. Sathe PS, Supriya Serology. Swati, Shubham, Supriya Sequence analysis. Tripathy AS Immunological. Parashar D Real time PCR. Gokhale M, Jacob George Entomological ...

  1. Interdisciplinarity and Team Teaching

    Science.gov (United States)

    Goodwin, William M.; LeBold, William K.

    1975-01-01

    Describes eight experimental courses in a series called the Man Series, instituted at Purdue University to improve the social dimensions of engineering education. Each course is team taught by engineering, humanities, and social science faculty members and is interdisciplinary in nature. (MLH)

  2. A Project Team: a Team or Just a Group?

    Directory of Open Access Journals (Sweden)

    Kateřina

    2014-06-01

    Full Text Available This paper deals with issues related to work in either teams or groups. The theoretical part discusses a team and a group with regards to its definition, classification and basic distinction, brings in more on the typology of team roles, personality assessment and sociometric methods. The analytical part tests the project (work team of a medical center represented in terms of personality and motivational types, team roles and interpersonal team relations concerning the willingness of cooperation and communication. The main objective of this work is to verify the validity of the assumptions that the analyzed team represents a very disparate group as for its composition from the perspective of personality types, types of motivation, team roles and interpersonal relations in terms of the willingness of cooperation and communication. A separate output shall focus on sociometric investigation of those team members where willingness to work together and communicate is based on the authors’ assumption of tight interdependence.

  3. Effects of team emotional authenticity on virtual team performance

    Directory of Open Access Journals (Sweden)

    Catherine E Connelly

    2016-08-01

    Full Text Available Members of virtual teams lack many of the visual or auditory cues that are usually used as the basis for impressions about fellow team members. We focus on the effects of the impressions formed in this context, and use social exchange theory to understand how these impressions affect team performance. Our pilot study, using content analysis (n = 191 students, suggested that most individuals believe that they can assess others’ emotional authenticity in online settings by focusing on the content and tone of the messages. Our quantitative study examined the effects of these assessments. Structural equation modeling (SEM analysis (n = 81 student teams suggested that team-level trust and teamwork behaviors mediate the relationship between team emotional authenticity and team performance, and illuminate the importance of team emotional authenticity for team processes and outcomes.

  4. Imagery Integration Team

    Science.gov (United States)

    Calhoun, Tracy; Melendrez, Dave

    2014-01-01

    The Human Exploration Science Office (KX) provides leadership for NASA's Imagery Integration (Integration 2) Team, an affiliation of experts in the use of engineering-class imagery intended to monitor the performance of launch vehicles and crewed spacecraft in flight. Typical engineering imagery assessments include studying and characterizing the liftoff and ascent debris environments; launch vehicle and propulsion element performance; in-flight activities; and entry, landing, and recovery operations. Integration 2 support has been provided not only for U.S. Government spaceflight (e.g., Space Shuttle, Ares I-X) but also for commercial launch providers, such as Space Exploration Technologies Corporation (SpaceX) and Orbital Sciences Corporation, servicing the International Space Station. The NASA Integration 2 Team is composed of imagery integration specialists from JSC, the Marshall Space Flight Center (MSFC), and the Kennedy Space Center (KSC), who have access to a vast pool of experience and capabilities related to program integration, deployment and management of imagery assets, imagery data management, and photogrammetric analysis. The Integration 2 team is currently providing integration services to commercial demonstration flights, Exploration Flight Test-1 (EFT-1), and the Space Launch System (SLS)-based Exploration Missions (EM)-1 and EM-2. EM-2 will be the first attempt to fly a piloted mission with the Orion spacecraft. The Integration 2 Team provides the customer (both commercial and Government) with access to a wide array of imagery options - ground-based, airborne, seaborne, or vehicle-based - that are available through the Government and commercial vendors. The team guides the customer in assembling the appropriate complement of imagery acquisition assets at the customer's facilities, minimizing costs associated with market research and the risk of purchasing inadequate assets. The NASA Integration 2 capability simplifies the process of securing one

  5. Team dynamics within quality improvement teams: a scoping review.

    Science.gov (United States)

    Rowland, Paula; Lising, Dean; Sinclair, Lynne; Baker, G Ross

    2018-03-31

    This scoping review examines what is known about the processes of quality improvement (QI) teams, particularly related to how teams impact outcomes. The aim is to provide research-informed guidance for QI leaders and to inform future research questions. Databases searched included: MedLINE, EMBASE, CINAHL, Web of Science and SCOPUS. Eligible publications were written in English, published between 1999 and 2016. Articles were included in the review if they examined processes of the QI team, were related to healthcare QI and were primary research studies. Studies were excluded if they had insufficient detail regarding QI team processes. Descriptive detail extracted included: authors, geographical region and health sector. The Integrated (Health Care) Team Effectiveness Model was used to synthesize findings of studies along domains of team effectiveness: task design, team process, psychosocial traits and organizational context. Over two stages of searching, 4813 citations were reviewed. Of those, 48 full-text articles are included in the synthesis. This review demonstrates that QI teams are not immune from dysfunction. Further, a dysfunctional QI team is not likely to influence practice. However, a functional QI team alone is unlikely to create change. A positive QI team dynamic may be a necessary but insufficient condition for implementing QI strategies. Areas for further research include: interactions between QI teams and clinical microsystems, understanding the role of interprofessional representation on QI teams and exploring interactions between QI team task, composition and process.

  6. 75 FR 65525 - Anthem Blue Cross Blue Shield, Claim Management Services, Inc. Operations, a Division of...

    Science.gov (United States)

    2010-10-25

    ... DEPARTMENT OF LABOR Employment and Training Administration [TA-W-74,327] Anthem Blue Cross Blue Shield, Claim Management Services, Inc. Operations, a Division of Wellpoint, Inc., Green Bay, WI; Notice... former workers of Anthem Blue Cross Blue Shield, Claim Management Services, Inc. Operations, a Division...

  7. Putting the "Team" in the Fine Arts Team: An Application of Business Management Team Concepts

    Science.gov (United States)

    Fisher, Ryan

    2007-01-01

    In this article, the author discusses current challenges to the idea of teamwork in fine arts teams, redefines the terms team and collaboration using a business management perspective, discusses the success of effective teams in the business world and the characteristics of those teams, and proposes the implementation of the business model of…

  8. Employee Knowledge Sharing in Work Teams: Effects of Team Diversity, Emergent States, and Team Leadership

    Science.gov (United States)

    Noh, Jae Hang

    2013-01-01

    Knowledge sharing in work teams is one of the critical team processes. Without sharing of knowledge, work teams and organizations may not be able to fully utilize the diverse knowledge brought into work teams by their members. The purpose of this study was to investigate antecedents and underlying mechanisms influencing the extent to which team…

  9. Improving Care Teams' Functioning: Recommendations from Team Science.

    Science.gov (United States)

    Fiscella, Kevin; Mauksch, Larry; Bodenheimer, Thomas; Salas, Eduardo

    2017-07-01

    Team science has been applied to many sectors including health care. Yet there has been relatively little attention paid to the application of team science to developing and sustaining primary care teams. Application of team science to primary care requires adaptation of core team elements to different types of primary care teams. Six elements of teams are particularly relevant to primary care: practice conditions that support or hinder effective teamwork; team cognition, including shared understanding of team goals, roles, and how members will work together as a team; leadership and coaching, including mutual feedback among members that promotes teamwork and moves the team closer to achieving its goals; cooperation supported by an emotionally safe climate that supports expression and resolution of conflict and builds team trust and cohesion; coordination, including adoption of processes that optimize efficient performance of interdependent activities among team members; and communication, particularly regular, recursive team cycles involving planning, action, and debriefing. These six core elements are adapted to three prototypical primary care teams: teamlets, health coaching, and complex care coordination. Implementation of effective team-based models in primary care requires adaptation of core team science elements coupled with relevant, practical training and organizational support, including adequate time to train, plan, and debrief. Training should be based on assessment of needs and tasks and the use of simulations and feedback, and it should extend to live action. Teamlets represent a potential launch point for team development and diffusion of teamwork principles within primary care practices. Copyright © 2017 The Joint Commission. Published by Elsevier Inc. All rights reserved.

  10. Synthesis of poly(3,4-propylenedioxythiophene/MnO2 composites and their applications in the adsorptive removal of methylene blue

    Directory of Open Access Journals (Sweden)

    Ruxangul Jamal

    2016-02-01

    Full Text Available The poly(3,4-propylenedioxythiophene/MnO2 composites (PProDOT/MnO2 were prepared successfully by soaking the PProDOT powders into potassium permanganate (KMnO4 solution, with the mass ratio of PProDOT and KMnO4 from 2:1 to 1:2. The structure and morphology of composites were characterized by Fourier transform infrared spectroscopy (FTIR, Raman spectroscopy, ultraviolet–visible absorption spectra (UV, X-ray diffraction (XRD, energy-dispersive X-ray spectroscopy (EDX and field emission scanning electron microscope (FE-SEM. Furthermore, PProDOT/MnO2 composites were tested as the adsorbents for removal of methylene blue (MB from aqueous solution. The results revealed that the composites were successfully synthesized, and the thiophene sulfur was oxidized into sulfoxide by KMnO4. The highest percentage removal of MB after 30 min was 91% for PProDOT/MnO2 (1:2 composite, and the percentage removal of MB was ~12 mg g−1 after 60 min at initial concentrations of MB dye of 5.6 mg L−1 in the case of PProDOT/MnO2 (1:2 composite. Besides, the adsorption process of PProDOT/MnO2 (1:2 composite was described by pseudo-second-order and Langmuir models.

  11. Personality and community prevention teams: Dimensions of team leader and member personality predicting team functioning.

    Science.gov (United States)

    Feinberg, Mark E; Kim, Ji-Yeon; Greenberg, Mark T

    2008-11-01

    The predictors and correlates of positive functioning among community prevention teams have been examined in a number of research studies; however, the role of personality has been neglected. In this study, we examined whether team member and leader personality dimensions assessed at the time of team formation predicted local prevention team functioning 2.5-3.5 years later. Participants were 159 prevention team members in 14 communities participating in the PROSPER study of prevention program dissemination. Three aspects of personality, aggregated at the team level, were examined as predictors: Openness to Experience, Conscientiousness, and Agreeableness. A series of multivariate regression analyses were performed that accounted for the interdependency of five categories of team functioning. Results showed that average team member Openness was negatively, and Conscientiousness was positively linked to team functioning. The findings have implications for decisions about the level and nature of technical assistance support provided to community prevention teams.

  12. The Physics of the Blues

    Science.gov (United States)

    Gibson, J. Murray

    2009-03-01

    In looking at the commonalities between music and science, one sees that the musician's palette is based on the principles of physics. The pitch of a musical note is determined by the frequency of the sound wave. The scales that musicians use to create and play music can be viewed as a set of rules. What makes music interesting is how musicians develop those rules and create ambiguity with them. I will discuss the evolution of western musical scales in this context. As a particular example, ``Blue'' notes are very harmonic notes that are missing from the equal temperament scale. The techniques of piano blues and jazz represent the melding of African and Western music into something totally new and exciting. Live keyboard demonstrations will be used. Beyond any redeeming entertainment value the talk will emphasize the serious connections between science and art in music. Nevertheless tips will be accepted.

  13. Blue breath holding is benign.

    OpenAIRE

    Stephenson, J B

    1991-01-01

    In their recent publication in this journal, Southall et al described typical cyanotic breath holding spells, both in otherwise healthy children and in those with brainstem lesions and other malformations. Their suggestions regarding possible autonomic disturbances may require further study, but they have adduced no scientific evidence to contradict the accepted view that in the intact child blue breath holding spells are benign. Those families in which an infant suffers an 'apparently life t...

  14. Sounds like Team Spirit

    Science.gov (United States)

    Hoffman, Edward

    2002-01-01

    I recently accompanied my son Dan to one of his guitar lessons. As I sat in a separate room, I focused on the music he was playing and the beautiful, robust sound that comes from a well-played guitar. Later that night, I woke up around 3 am. I tend to have my best thoughts at this hour. The trouble is I usually roll over and fall back asleep. This time I was still awake an hour later, so I got up and jotted some notes down in my study. I was thinking about the pure, honest sound of a well-played instrument. From there my mind wandered into the realm of high-performance teams and successful projects. (I know this sounds weird, but this is the sort of thing I think about at 3 am. Maybe you have your own weird thoughts around that time.) Consider a team in relation to music. It seems to me that a crack team can achieve a beautiful, perfect unity in the same way that a band of brilliant musicians can when they're in harmony with one another. With more than a little satisfaction I have to admit, I started to think about the great work performed for you by the Knowledge Sharing team, including this magazine you are reading. Over the past two years I personally have received some of my greatest pleasures as the APPL Director from the Knowledge Sharing activities - the Masters Forums, NASA Center visits, ASK Magazine. The Knowledge Sharing team expresses such passion for their work, just like great musicians convey their passion in the music they play. In the case of Knowledge Sharing, there are many factors that have made this so enjoyable (and hopefully worthwhile for NASA). Three ingredients come to mind -- ingredients that have produced a signature sound. First, through the crazy, passionate playing of Alex Laufer, Michelle Collins, Denise Lee, and Todd Post, I always know that something startling and original is going to come out of their activities. This team has consistently done things that are unique and innovative. For me, best of all is that they are always

  15. Physics and engineering of compact quantum dot-based lasers for biophotonics

    CERN Document Server

    Rafailov, Edik U

    2013-01-01

    Written by a team of European experts in the field, this book addresses the physics, the principles, the engineering methods, and the latest developments of efficient and compact ultrafast lasers based on novel quantum-dot structures and devices, as well as their applications in biophotonics. Recommended reading for physicists, engineers, students and lecturers in the fields of photonics, optics, laser physics, optoelectronics, and biophotonics.

  16. On teams, teamwork, and team performance: discoveries and developments.

    Science.gov (United States)

    Salas, Eduardo; Cooke, Nancy J; Rosen, Michael A

    2008-06-01

    We highlight some of the key discoveries and developments in the area of team performance over the past 50 years, especially as reflected in the pages of Human Factors. Teams increasingly have become a way of life in many organizations, and research has kept up with the pace. We have characterized progress in the field in terms of eight discoveries and five challenges. Discoveries pertain to the importance of shared cognition, the measurement of shared cognition, advances in team training, the use of synthetic task environments for research, factors influencing team effectiveness, models of team effectiveness, a multidisciplinary perspective, and training and technological interventions designed to improve team effectiveness. Challenges that are faced in the coming decades include an increased emphasis on team cognition; reconfigurable, adaptive teams; multicultural influences; and the need for naturalistic study and better measurement. Work in human factors has contributed significantly to the science and practice of teams, teamwork, and team performance. Future work must keep pace with the increasing use of teams in organizations. The science of teams contributes to team effectiveness in the same way that the science of individual performance contributes to individual effectiveness.

  17. Direct and indirect fluorescent detection of tetracyclines using dually emitting carbon dots

    International Nuclear Information System (INIS)

    Qu, Fei; Sun, Zhe; Liu, Dongya; Zhao, Xianen; You, Jinmao

    2016-01-01

    The authors describe dual-emission carbon nanodots containing blue emitters (BE; peak emission at 385 nm under 315 nm excitation) and yellow emitters (YE; peak emission at 530 nm under 365 nm excitation), and how they can be applied to direct and indirect determination of tetracyclines (TCs). The direct detection scheme is based on the finding that tetracycline (TET), oxytetracycline, chlortetracycline and doxycycline quench the two emissions of the carbon dots. While direct determination is rapid and convenient, it cannot differentiate between TCs. The indirect detection scheme, in contrast, is based on the finding that Al (III) ions enhance the fluorescence of the YE in the carbon dots, and that they cause a blue shift in emission. It is, however, known that TET forms a strong complex with Al (III), and this can inhibit the interaction between Al (III) and the YE, so that the fluorescence of YE is not enhanced and blue-shifted by Al (III) in the presence of TET. This finding is exploited in a fluorescence turn-on/off assay for TET that can distinguish TET from other TCs. The linear range of indirect determination for TET extends from 1 nM to 30 μM, and the limit of detection is 0.52 nM. The indirect method was successfully applied to the determination of TET in spiked milk, fish and pork, and recoveries ranged from 91.7 to 102 %. (author)

  18. The role of surface and deep-level defects on the emission of tin oxide quantum dots

    International Nuclear Information System (INIS)

    Kumar, Vinod; Kumar, Vijay; Som, S; Ntwaeaborwa, O M; Swart, H C; Neethling, J H; Lee, Mike

    2014-01-01

    This paper reports on the role of surface and deep-level defects on the blue emission of tin oxide quantum dots (SnO 2 QDs) synthesized by the solution-combustion method at different combustion temperatures. X-ray diffraction studies showed the formation of a single rutile SnO 2 phase with a tetragonal lattice structure. High resolution transmission electron microscopy studies revealed an increase in the average dot size from 2.2 to 3.6 nm with an increase of the combustion temperature from 350 to 550 °C. A decrease in the band gap value from 3.37 to 2.76 eV was observed with the increase in dot size due to the quantum confinement effect. The photoluminescence emission was measured for excitation at 325 nm and it showed a broad blue emission band for all the combustion temperatures studied. This was due to the creation of various oxygen and tin vacancies/defects as confirmed by x-ray photoelectron spectroscopy data. The origin of the blue emission in the SnO 2 QDs is discussed with the help of an energy band diagram. (paper)

  19. dotNet som multimediaplattform

    OpenAIRE

    Johansson, Glenn

    2008-01-01

    As the speed and complexity of computers have increased so have software and the expectations of users. Software development follows a straightforward evolution where complicated tasks are made easier by better tools; this repeats itself as those tasks in turn are automated. Software mechanics that were seen as revolutionary a decade ago are seen as obvious requirements that no multimedia application can be without. dotNet is the next step in line and makes it easier and faster to build softw...

  20. Dicke states in multiple quantum dots

    Science.gov (United States)

    Sitek, Anna; Manolescu, Andrei

    2013-10-01

    We present a theoretical study of the collective optical effects which can occur in groups of three and four quantum dots. We define conditions for stable subradiant (dark) states, rapidly decaying super-radiant states, and spontaneous trapping of excitation. Each quantum dot is treated like a two-level system. The quantum dots are, however, realistic, meaning that they may have different transition energies and dipole moments. The dots interact via a short-range coupling which allows excitation transfer across the dots, but conserves the total population of the system. We calculate the time evolution of single-exciton and biexciton states using the Lindblad equation. In the steady state the individual populations of each dot may have permanent oscillations with frequencies given by the energy separation between the subradiant eigenstates.

  1. Hydrogenic impurity in double quantum dots

    International Nuclear Information System (INIS)

    Wang, X.F.

    2007-01-01

    The ground state binding energy and the average interparticle distances for a hydrogenic impurity in double quantum dots with Gaussian confinement potential are studied by the variational method. The probability density of the electron is calculated, too. The dependence of the binding energy on the impurity position is investigated for GaAs quantum dots. The result shows that the binding energy has a minimum as a function of the distance between the two quantum dots when the impurity is located at the center of one quantum dot or at the center of the edge of one quantum dot. When the impurity is located at the center of the two dots, the binding energy decreases monotonically

  2. Career Concerns in Teams

    OpenAIRE

    Auriol, Emmanuelle; Friebel, Guido; Pechlivanos, Lambros

    2002-01-01

    We investigate how changes in the commitment power of a principal affect cooperation among agents who work in a team. When the principal and her agents are symmetrically uncertain about the agents' innate abilities, workers have career concerns. Then, unless the principal can commit herself to long-term wage contracts, an implicit sabotage incentive emerges. Agents become reluctant to help their teammates. Anticipating this risk, and in order to induce the desired level of cooperation, the pr...

  3. Professional Team Sports Clubs

    DEFF Research Database (Denmark)

    Storm, Rasmus K.

    Professional football in Europe is characterized by persistent deficits, growing debts and additional financial problems among the majority of the top league clubs. Despite these problems, these clubs have an abnormally high survival rate. This paper focuses on this apparent paradox and poses the...... in Europe, this paper argues that professional team sports clubs (PTSCs) are cases of an economic phenomenon normally found in socialist or post-socialist economies....

  4. The Motivated Project Team

    Science.gov (United States)

    2009-12-01

    Financial incentives that match level of achievement • Regular, constructive feedback. Hierarchy of Needs ( Abraham H. Maslow ) Team members can be...Much has been written regarding motivational Defense AT&L: November-December 2009 58 theory . To further complicate mat- ters, some motivational... theories clearly contradict others, and a manager’s ability to motivate is, to no small degree, related to his or her leadership approach and inter

  5. Rapid improvement teams.

    Science.gov (United States)

    Alemi, F; Moore, S; Headrick, L; Neuhauser, D; Hekelman, F; Kizys, N

    1998-03-01

    Suggestions, most of which are supported by empirical studies, are provided on how total quality management (TQM) teams can be used to bring about faster organizationwide improvements. Ideas are offered on how to identify the right problem, have rapid meetings, plan rapidly, collect data rapidly, and make rapid whole-system changes. Suggestions for identifying the right problem include (1) postpone benchmarking when problems are obvious, (2) define the problem in terms of customer experience so as not to blame employees nor embed a solution in the problem statement, (3) communicate with the rest of the organization from the start, (4) state the problem from different perspectives, and (5) break large problems into smaller units. Suggestions for having rapid meetings include (1) choose a nonparticipating facilitator to expedite meetings, (2) meet with each team member before the team meeting, (3) postpone evaluation of ideas, and (4) rethink conclusions of a meeting before acting on them. Suggestions for rapid planning include reducing time spent on flowcharting by focusing on the future, not the present. Suggestions for rapid data collection include (1) sample patients for surveys, (2) rely on numerical estimates by process owners, and (3) plan for rapid data collection. Suggestions for rapid organizationwide implementation include (1) change membership on cross-functional teams, (2) get outside perspectives, (3) use unfolding storyboards, and (4) go beyond self-interest to motivate lasting change in the organization. Additional empirical investigations of time saved as a consequence of the strategies provided are needed. If organizations solve their problems rapidly, fewer unresolved problems may remain.

  6. Building multidisciplinary business teams

    International Nuclear Information System (INIS)

    Dyson, C.J.; Winter, N.C.

    1992-01-01

    This paper describes an approach to managing oil and gas industry E and P assets through the operation of multidisciplinary business teams (MBT's). This approach can result in improved asset performance in terms of efficiency, motivation, and business results compared with more traditional matrix-style hierarchies. This paper also outlines certain critical success factors for the long-term success of MBT's and discusses some of the risks of MBT operation

  7. Sphere and dot product representations of graphs

    NARCIS (Netherlands)

    R.J. Kang (Ross); T. Müller (Tobias)

    2012-01-01

    textabstractA graph $G$ is a $k$-sphere graph if there are $k$-dimensional real vectors $v_1,\\dots,v_n$ such that $ij\\in E(G)$ if and only if the distance between $v_i$ and $v_j$ is at most $1$. A graph $G$ is a $k$-dot product graph if there are $k$-dimensional real vectors $v_1,\\dots,v_n$ such

  8. Nutrition in team sports.

    Science.gov (United States)

    Mujika, Iñigo; Burke, Louise M

    2010-01-01

    Team sports are based on intermittent high-intensity activity patterns, but the exact characteristics vary between and within codes, and from one game to the next. Despite the challenge of predicting exact game demands, performance in team sports is often dependent on nutritional factors. Chronic issues include achieving ideal levels of muscle mass and body fat, and supporting the nutrient needs of the training program. Acute issues, both for training and in games, include strategies that allow the player to be well fuelled and hydrated over the duration of exercise. Each player should develop a plan of consuming fluid and carbohydrate according to the needs of their activity patterns, within the breaks that are provided in their sport. In seasonal fixtures, competition varies from a weekly game in some codes to 2-3 games over a weekend road trip in others, and a tournament fixture usually involves 1-3 days between matches. Recovery between events is a major priority, involving rehydration, refuelling and repair/adaptation activities. Some sports supplements may be of value to the team athlete. Sports drinks, gels and liquid meals may be valuable in allowing nutritional goals to be met, while caffeine, creatine and buffering agents may directly enhance performance. Copyright © 2011 S. Karger AG, Basel.

  9. Collocation Impact on Team Effectiveness

    Directory of Open Access Journals (Sweden)

    M Eccles

    2010-11-01

    Full Text Available The collocation of software development teams is common, specially in agile software development environments. However little is known about the impact of collocation on the team’s effectiveness. This paper explores the impact of collocating agile software development teams on a number of team effectiveness factors. The study focused on South African software development teams and gathered data through the use of questionnaires and interviews. The key finding was that collocation has a positive impact on a number of team effectiveness factors which can be categorised under team composition, team support, team management and structure and team communication. Some of the negative impact collocation had on team effectiveness relate to the fact that team members perceived that less emphasis was placed on roles, that morale of the group was influenced by individuals, and that collocation was invasive, reduced level of privacy and increased frequency of interruptions. Overall through it is proposed that companies should consider collocating their agile software development teams, as collocation might leverage overall team effectiveness.

  10. Electronic transport through a quantum dot chain with strong dot-lead coupling

    International Nuclear Information System (INIS)

    Liu, Yu; Zheng, Yisong; Gong, Weijiang; Gao, Wenzhu; Lue, Tianquan

    2007-01-01

    By means of the non-equilibrium Green function technique, the electronic transport through an N-quantum-dot chain is theoretically studied. By calculating the linear conductance spectrum and the local density of states in quantum dots, we find the resonant peaks in the spectra coincides with the eigen-energies of the N-quantum-dot chain when the dot-lead coupling is relatively weak. With the increase of the dot-lead coupling, such a correspondence becomes inaccurate. When the dot-lead coupling exceeds twice the interdot coupling, such a mapping collapses completely. The linear conductance turn to reflect the eigen-energies of the (N-2)- or (N-1)-quantum dot chain instead. The two peripheral quantum dots do not manifest themselves in the linear conductance spectrum. More interestingly, with the further increase of the dot-lead coupling, the system behaves just like an (N-2)- or (N-1)-quantum dot chain in weak dot-lead coupling limit, since the resonant peaks becomes narrower with the increase of dot-lead coupling

  11. Today's DOT and the quest for more accountable organizational structures.

    Science.gov (United States)

    2005-12-01

    This study investigates the impact of DOT organizational structures on effective transportation planning and performance. A review of the 50 state DOT authorizing statutes and DOT organizational charts found minimal differences in organizational stru...

  12. Cohesion in Online Student Teams versus Traditional Teams

    Science.gov (United States)

    Hansen, David E.

    2016-01-01

    Researchers have found that the electronic methods in use for online team communication today increase communication quality in project-based work situations. Because communication quality is known to influence group cohesion, the present research examined whether online student project teams are more cohesive than traditional teams. We tested…

  13. Using artificial team members for team training in virtual environments

    NARCIS (Netherlands)

    Diggelen, J. van; Muller, T.; Bosch, K. van den

    2010-01-01

    In a good team, members do not only perform their individual task, they also coordinate their actions with other members of the team. Developing such team skills usually involves exercises with all members playing their role. This approach is costly and has organizational and educational drawbacks.

  14. Hoe teams deadlines halen : een aanzet tot team-timemanagement

    NARCIS (Netherlands)

    Gevers, J.M.P.; Rutte, C.G.

    2014-01-01

    Dit artikel geeft een overzicht van de stand van zaken in de wetenschappelijk literatuur ten aanzien van de vraag hoe teams hun deadlines halen. Het beschikbare materiaal wijst erop dat teams beter in staat zijn om deadlines te halen als teamleden, naast een gemeenschappelijke visie op het team en

  15. Teams, Team Motivation, and the Theory of the Firm

    DEFF Research Database (Denmark)

    Foss, Nicolai Juul; Lindenberg, Siegwart

    A concern with teams was central to early attempts to grasp the nature of the firm, but fell out of favor in later work. We encourage a return to the emphasis on teams, but argue that the idea of teams as central to the nature of the firm needs to be grounded in an appreciation of the importance...

  16. Quantum dots for quantum information technologies

    CERN Document Server

    2017-01-01

    This book highlights the most recent developments in quantum dot spin physics and the generation of deterministic superior non-classical light states with quantum dots. In particular, it addresses single quantum dot spin manipulation, spin-photon entanglement and the generation of single-photon and entangled photon pair states with nearly ideal properties. The role of semiconductor microcavities, nanophotonic interfaces as well as quantum photonic integrated circuits is emphasized. The latest theoretical and experimental studies of phonon-dressed light matter interaction, single-dot lasing and resonance fluorescence in QD cavity systems are also provided. The book is written by the leading experts in the field.

  17. Semiconductor quantum-dot lasers and amplifiers

    DEFF Research Database (Denmark)

    Hvam, Jørn Märcher; Borri, Paola; Ledentsov, N. N.

    2002-01-01

    -power surface emitting VCSELs. We investigated the ultrafast dynamics of quantum-dot semiconductor optical amplifiers. The dephasing time at room temperature of the ground-state transition in semiconductor quantum dots is around 250 fs in an unbiased amplifier, decreasing to below 50 fs when the amplifier...... is biased to positive net gain. We have further measured gain recovery times in quantum dot amplifiers that are significantly lower than in bulk and quantum-well semiconductor optical amplifiers. This is promising for future demonstration of quantum dot devices with high modulation bandwidth...

  18. Millimeter Wave Modulators Using Quantum Dots

    National Research Council Canada - National Science Library

    Prather, Dennis W

    2008-01-01

    In this effort electro-optic modulators for millimeter wave sensing and imaging were developed and demonstrated via design, fabrication, and experimental characterization of multi layer quantum dot...

  19. Spin Switching via Quantum Dot Spin Valves

    Science.gov (United States)

    Gergs, N. M.; Bender, S. A.; Duine, R. A.; Schuricht, D.

    2018-01-01

    We develop a theory for spin transport and magnetization dynamics in a quantum dot spin valve, i.e., two magnetic reservoirs coupled to a quantum dot. Our theory is able to take into account effects of strong correlations. We demonstrate that, as a result of these strong correlations, the dot gate voltage enables control over the current-induced torques on the magnets and, in particular, enables voltage-controlled magnetic switching. The electrical resistance of the structure can be used to read out the magnetic state. Our model may be realized by a number of experimental systems, including magnetic scanning-tunneling microscope tips and artificial quantum dot systems.

  20. Optical Signatures of Coupled Quantum Dots

    Science.gov (United States)

    Stinaff, E. A.; Scheibner, M.; Bracker, A. S.; Ponomarev, I. V.; Korenev, V. L.; Ware, M. E.; Doty, M. F.; Reinecke, T. L.; Gammon, D.

    2006-02-01

    An asymmetric pair of coupled InAs quantum dots is tuned into resonance by applying an electric field so that a single hole forms a coherent molecular wave function. The optical spectrum shows a rich pattern of level anticrossings and crossings that can be understood as a superposition of charge and spin configurations of the two dots. Coulomb interactions shift the molecular resonance of the optically excited state (charged exciton) with respect to the ground state (single charge), enabling light-induced coupling of the quantum dots. This result demonstrates the possibility of optically coupling quantum dots for application in quantum information processing.

  1. Organic molecules passivated Mn doped Zinc Selenide quantum dots and its properties

    International Nuclear Information System (INIS)

    Archana, J.; Navaneethan, M.; Ponnusamy, S.; Hayakawa, Y.; Muthamizhchelvan, C.

    2011-01-01

    Quantum dots of Mn doped Zinc Selenide with N-Methylaniline as the capping agent was prepared by simple and inexpensive wet chemical method. Size of the particles observed by TEM was of the order of 2-4 nm which was well consistent with the size measured by UV analysis. The presence of paramagnetic substance Mn 2+ in the ZnSe quantum dots was confirmed by EPR measurement. Mn doped ZnSe nanoparticles exhibited a strong blue emission that was strongly dependent upon the Mn dopant level and the surface passivation produced by N-Methylaniline. The stability of the product was studied by thermal analysis which shows that this product is highly suitable for opto-electronic applications.

  2. Electrical aging effect of ZnS based quantum dots for white light-emitting diodes

    Science.gov (United States)

    Kim, Yohan; Ippen, Christian; Greco, Tonino; Jang, Ilwan; Park, Sungkyu; Oh, Min Suk; Han, Chul Jong; Lee, Jeongno; Wedel, Armin; Kim, Jiwan

    2014-03-01

    The present work reports cadmium-free colloidal ZnS:Al quantum dot (QD) based white quantum dot light-emitting diodes (QD-LEDs). The device was fabricated with a structure of ITO/PEDOT:PSS/PVK/QDs/TPBi/LiF/Al using synthesized ZnS:Al QDs which has 393 nm of peak wavelength and sub peaks in visible wavelength. White emission with high color rending index (CRI) was achieved by the combination of blue emission from PVK and ZnS:Al QDs, electroplex emission at the interface between PVK and ZnS:Al QDs, and Al traps/defects emission, which are controlled by electrical aging effect. The characteristic of our device shows the potential for spectrum tunable and Cd-free white QD-LEDs in the near future.

  3. Synthesis and characterization of graphene quantum dots and their size reduction using swift heavy ion beam

    Science.gov (United States)

    Mishra, Praveen; Bhat, Badekai Ramchandra

    2018-04-01

    Graphene quantum dots (GQDs) are nanosized fragments of graphene displaying quantum confinement effect. They have shown to be prepared from various methods which include ion beam etching of graphene. However, recently the modification of the GQDs has garnered tremendous attention owing to its suitability for various applications. Here, we have studied the effect of swift ion beam irradiation on the properties of GQDs. The ion beam treatment on the GQDs exhibited the change in observed photoluminescence of GQDs as they exhibited a blue luminescence on excitation with longwave UV (≈365 nm) due to the reduction in size and removal of the ethoxy (-C-O-C-) groups present on the quantum dots. This was confirmed by transmission electron microscopy, particle size analysis, and Fourier transform infrared spectroscopy.

  4. Leadership Team | Water Power | NREL

    Science.gov (United States)

    Leadership Team Leadership Team Learn more about the expertise and technical skills of the water Initiative and provides leadership in the focus areas of high-fidelity modeling, wind power plant controls

  5. Diverse Teams Drive Leadership Development

    DEFF Research Database (Denmark)

    Holck, Lotte; Hjortlund Andersen, Lotte

    New research from ISS Denmark shows that leading diverse teams strengthens leaders’ competencies within communication, relationship building and talent development and ensures inclusion. This has a reinforcing effect as the better the leadership, the better the heterogeneous team will function....

  6. Team Dynamics. Implications for Coaching.

    Science.gov (United States)

    Freishlag, Jerry

    1985-01-01

    A recent survey of coaches ranks team cohesion as the most critical problem coaches face. Optimal interpersonal relationships among athletes and their coaches can maximize collective performance. Team dynamics are discussed and coaching tips are provided. (MT)

  7. Cultural Diversity and Team Performance

    DEFF Research Database (Denmark)

    Hoogendoorn, Sander; Van Praag, Mirjam

    One of the most salient and relevant dimensions of team heterogeneity is cultural background. We measure the impact of cultural diversity on the performance of business teams using a field experiment. Companies are set up by teams of undergraduate students in business studies in realistic though...... similar circumstances. We vary the cultural composition of otherwise randomly composed teams in a multi-cultural student population. Our data indicate that a moderate level of cultural diversity has no effect on team performance in terms of business outcomes (sales, profits and profits per share). However......, if at least the majority of team members is culturally diverse then more cultural diversity seems to affect the performance of teams positively. Our data suggest that this might be related to the more diverse pool of relevant knowledge facilitating (mutual) learning within culturally diverse teams....

  8. Novel cookie-with-chocolate carbon dots displaying extremely acidophilic high luminescence

    Science.gov (United States)

    Lu, Siyu; Zhao, Xiaohuan; Zhu, Shoujun; Song, Yubin; Yang, Bai

    2014-10-01

    A fluorescent carbon dot with a cookie-with-chocolate film structure (about 5 × 5 μm2) showed a high fluorescence quantum yield (61.12%) at low pH. It was hydrothermally synthesized from l-serine and l-tryptophan. The formation mechanism of the film with carbon dots (CDs) was investigated. The film structure was formed by hydrogen bonding and π-π stacking interactions between aromatic rings. The strong blue fluorescence of the CDs increased under strong acidic conditions owing to the changes in the N-groups. These cookie-like CDs are attractive for their potential use as effective fluorescent probes for the sensitive detection of aqueous H+ and Fe3+.A fluorescent carbon dot with a cookie-with-chocolate film structure (about 5 × 5 μm2) showed a high fluorescence quantum yield (61.12%) at low pH. It was hydrothermally synthesized from l-serine and l-tryptophan. The formation mechanism of the film with carbon dots (CDs) was investigated. The film structure was formed by hydrogen bonding and π-π stacking interactions between aromatic rings. The strong blue fluorescence of the CDs increased under strong acidic conditions owing to the changes in the N-groups. These cookie-like CDs are attractive for their potential use as effective fluorescent probes for the sensitive detection of aqueous H+ and Fe3+. Electronic supplementary information (ESI) available. See DOI: 10.1039/c4nr03965c

  9. It's a team game: exploring factors that influence team experience

    OpenAIRE

    Martin, Eleanor

    2015-01-01

    Many multiplayer games feature teams, and whether they are pitted against each other or against the game itself it seems likely that the way these teams bond will affect the players' experience. What are the factors that influence the experience of being a team member in a game? To what extent can the game designer manipulate the cohesion of the teams by changing the game design? How does the satisfaction of the player with their team relate to their feeling of cohesion? How does cohesion dif...

  10. Liquid biofuels from blue biomass

    DEFF Research Database (Denmark)

    Kádár, Zsófia; Jensen, Annette Eva; Bangsø Nielsen, Henrik

    2011-01-01

    Marine (blue) biomasses, such as macroalgaes, represent a huge unexploited amount of biomass. With their various chemical compositions, macroalgaes can be a potential substrate for food, feed, biomaterials, pharmaceuticals, health care products and also for bioenergy. Algae use seawater as a growth...... medium, light as energy source and they capture CO2 for the synthesis of new organic material, thus can grow on non-agricultural land, without increasing food prices, or using fresh water. Due to all these advantages in addition to very high biomass yield with high carbohydrate content, macroalgaes can...

  11. Markkinointisuunnitelma Case: Ringetteseura Blue Rings

    OpenAIRE

    Seppälä, Minna

    2012-01-01

    Tämän opinnäytetyön tarkoituksena on markkinointisuunnitelman laatiminen ringetteseura Blue Ringsin edustusjoukkueelle. Lähtökohtana on pidetty suunnitelman toteutuskelpoisuutta käytännössä sekä suunnitelman reaalisuutta. Opinnäytetyö on toteutettu projektityönä, jossa on käytetty benchmarkkauksen lisäksi sekä kvalitatiivisia että empiirisiä tutkimusmenetelmiä. Opinnäytetyö koostuu kahdesta osiosta; teoreettinen viitekehys sekä empiirinen osio. Teoriana opinnäytetyössä on käytetty markkinoinn...

  12. The cohesiveness of sourcing teams

    DEFF Research Database (Denmark)

    Lidegaard, Nina

    2015-01-01

    Sourcing teams are introduced as an approach to achieving the interdepartmental integration necessary for companies to address the complexity of strategic sourcing. Companies aim at facilitating teams capable of balancing the goals and tasks of the team with departmental expectations; however...

  13. Entrepreneurial team cognition: A review

    NARCIS (Netherlands)

    de Mol, E.; Khapova, S.N.; Elfring, T.

    2015-01-01

    Entrepreneurial team scholars highlight the importance of studying entrepreneurial team cognition in gaining a better understanding of why some entrepreneurial teams are capable of developing teamwork leading to successful entrepreneurial outcomes while others are not. However, in the absence of a

  14. Ability Dispersion and Team Performance

    DEFF Research Database (Denmark)

    Hoogendoorn, Sander; Parker, Simon C.; Van Praag, Mirjam

    What is the effect of dispersed levels of cognitive ability of members of a (business) team on their team's performance? This paper reports the results of a field experiment in which 573 students in 49 teams start up and manage real companies under identical circumstances. We ensured exogenous va...

  15. Team Based Engineering Design Thinking

    Science.gov (United States)

    Mentzer, Nathan

    2014-01-01

    The objective of this research was to explore design thinking among teams of high school students. This objective was encompassed in the research question driving the inquiry: How do teams of high school students allocate time across stages of design? Design thinking on the professional level typically occurs in a team environment. Many…

  16. Enabling Team Learning in Healthcare

    Science.gov (United States)

    Boak, George

    2016-01-01

    This paper is based on a study of learning processes within 35 healthcare therapy teams that took action to improve their services. The published research on team learning is introduced, and the paper suggests it is an activity that has similarities with action research and with those forms of action learning where teams address collective…

  17. A Project Team: A Team or Just a Group?

    Directory of Open Access Journals (Sweden)

    Katerina Hrazdilova Bockova

    2013-11-01

    Full Text Available This paper deals with issues related to work in either teams or groups. The theoretical part which discusses a team and a group with regards to its definition, classification and basic distinction brings in more on the typology of team roles, personality assessment and sociometric methods. The analytical part tests the project (work team of a medical center represented in terms of personality and motivational types, team roles and interpersonal team relations concerning the willingness of cooperation and communication. The main objective of this work was to determine whether the existing team is not by its nature rather a working group that contributes to the generally perceived stagnation of that field.

  18. Vectorization of DOT3.5 code

    International Nuclear Information System (INIS)

    Nonomiya, Iwao; Ishiguro, Misako; Tsutsui, Tsuneo

    1990-07-01

    In this report, we describe the vectorization of two-dimensional Sn-method radiation transport code DOT3.5. Vectorized codes are not only the NEA original version developed at ORNL but also the versions improved by JAERI: DOT3.5 FNS version for fusion neutronics analyses, DOT3.5 FER version for fusion reactor design, and ESPRIT module of RADHEAT-V4 code system for radiation shielding and radiation transport analyses. In DOT3.5, input/output processing time amounts to a great part of the elapsed time when a large number of energy groups and/or a large number of spatial mesh points are used in the calculated problem. Therefore, an improvement has been made for the speedup of input/output processing in the DOT3.5 FNS version, and DOT-DD (Double Differential cross section) code. The total speedup ratio of vectorized version to the original scalar one is 1.7∼1.9 for DOT3.5 NEA version, 2.2∼2.3 fro DOT3.5 FNS version, 1.7 for DOT3.5 FER version, and 3.1∼4.4 for RADHEAT-V4, respectively. The elapsed times for improved DOT3.5 FNS version and DOT-DD are reduced to 50∼65% that of the original version by the input/output speedup. In this report, we describe summary of codes, the techniques used for the vectorization and input/output speedup, verification of computed results, and speedup effect. (author)

  19. Geospatial Information Response Team

    Science.gov (United States)

    Witt, Emitt C.

    2010-01-01

    Extreme emergency events of national significance that include manmade and natural disasters seem to have become more frequent during the past two decades. The Nation is becoming more resilient to these emergencies through better preparedness, reduced duplication, and establishing better communications so every response and recovery effort saves lives and mitigates the long-term social and economic impacts on the Nation. The National Response Framework (NRF) (http://www.fema.gov/NRF) was developed to provide the guiding principles that enable all response partners to prepare for and provide a unified national response to disasters and emergencies. The NRF provides five key principles for better preparation, coordination, and response: 1) engaged partnerships, 2) a tiered response, 3) scalable, flexible, and adaptable operations, 4) unity of effort, and 5) readiness to act. The NRF also describes how communities, tribes, States, Federal Government, privatesector, and non-governmental partners apply these principles for a coordinated, effective national response. The U.S. Geological Survey (USGS) has adopted the NRF doctrine by establishing several earth-sciences, discipline-level teams to ensure that USGS science, data, and individual expertise are readily available during emergencies. The Geospatial Information Response Team (GIRT) is one of these teams. The USGS established the GIRT to facilitate the effective collection, storage, and dissemination of geospatial data information and products during an emergency. The GIRT ensures that timely geospatial data are available for use by emergency responders, land and resource managers, and for scientific analysis. In an emergency and response capacity, the GIRT is responsible for establishing procedures for geospatial data acquisition, processing, and archiving; discovery, access, and delivery of data; anticipating geospatial needs; and providing coordinated products and services utilizing the USGS' exceptional pool of

  20. Survey team on

    DEFF Research Database (Denmark)

    Niss, Mogens Allan; Bruder, Regina; Planas, Núria

    2016-01-01

    This paper presents the outcomes of the work of the ICME 13 Survey Team on ‘Conceptualisation and the role of competencies, knowing and knowledge in mathematics education research’. It surveys a variety of historical and contemporary views and conceptualisations of what it means to master...... mathematics, focusing on notions such as mathematical competence and competencies, mathematical proficiency, and mathematical practices, amongst others. The paper provides theoretical analyses of these notions—under the generic heading of mathematical competencies—and gives an overview of selected research...

  1. Volunteer Team Management

    OpenAIRE

    Monych, Maria

    2015-01-01

    This thesis looked into volunteer team management in a project in AIESEC in Finland through the action research method. AIESEC in Finland is a non-profit non-government organization with a purpose of “peace and fulfilment of humankinds potential” through development of the youth’s future leadership. AIESEC was not a commissioning party; the project was the basis for the thesis without the supervision of the company. The thesis is based on a project that the author was in charge of, in ...

  2. Launch team training system

    Science.gov (United States)

    Webb, J. T.

    1988-01-01

    A new approach to the training, certification, recertification, and proficiency maintenance of the Shuttle launch team is proposed. Previous training approaches are first reviewed. Short term program goals include expanding current training methods, improving the existing simulation capability, and scheduling training exercises with the same priority as hardware tests. Long-term goals include developing user requirements which would take advantage of state-of-the-art tools and techniques. Training requirements for the different groups of people to be trained are identified, and future goals are outlined.

  3. Materials challenges for devices based on single, self-assembled InGaN quantum dots

    International Nuclear Information System (INIS)

    Oliver, Rachel A; Jarjour, Anas F; Tahraoui, Abbes; Kappers, Menno J; Taylor, Robert A; Humphreys, Colin J

    2007-01-01

    Builiding on earlier studies of single InGaN quantum dots (QDs), we are considering their potential for use in blue- and green-emitting single photon sources. Envisaging a device based on a resonant cavity light emitting diode, we have studied the effect of growing QDs on an underlying AlN/GaN distributed Bragg reflector, and have shown that enhanced single QD emission may be obtained. Additionally, we have studied the effect of the growth and activation of a p-type cap on an underlying QD layer and have shown that the QDs survive the anneal process

  4. Team player styles, team design variables and team work effectiveness in Egypt

    OpenAIRE

    El-Kot, Ghada Awed Hassan

    2001-01-01

    The literature has revealed few studies of management in Arab countries in general and particularly in Egypt. Many Egyptian organisations implemented the team concept a number of years ago, however, there do not appear to be any studies investicitaýt inc",D team work effectiveness in Egypt. The literature review and the findings of a pilot study emphasised the need for empirical research in team work in Egypt. Team effectiveness models are examined in order to identify the fact...

  5. Electronic properties of blue phosphorene/graphene and blue phosphorene/graphene-like gallium nitride heterostructures.

    Science.gov (United States)

    Sun, Minglei; Chou, Jyh-Pin; Yu, Jin; Tang, Wencheng

    2017-07-05

    Blue phosphorene (BlueP) is a graphene-like phosphorus nanosheet which was synthesized very recently for the first time [Nano Lett., 2016, 16, 4903-4908]. The combination of electronic properties of two different two-dimensional materials in an ultrathin van der Waals (vdW) vertical heterostructure has been proved to be an effective approach to the design of novel electronic and optoelectronic devices. Therefore, we used density functional theory to investigate the structural and electronic properties of two BlueP-based heterostructures - BlueP/graphene (BlueP/G) and BlueP/graphene-like gallium nitride (BlueP/g-GaN). Our results showed that the semiconducting nature of BlueP and the Dirac cone of G are well preserved in the BlueP/G vdW heterostructure. Moreover, by applying a perpendicular electric field, it is possible to tune the position of the Dirac cone of G with respect to the band edge of BlueP, resulting in the ability to control the Schottky barrier height. For the BlueP/g-GaN vdW heterostructure, BlueP forms an interface with g-GaN with a type-II band alignment, which is a promising feature for unipolar electronic device applications. Furthermore, we discovered that both G and g-GaN can be used as an active layer for BlueP to facilitate charge injection and enhance the device performance.

  6. Sialylglycan-Assembled Supra-Dots for Ratiometric Probing and Blocking of Human-Infecting Influenza Viruses.

    Science.gov (United States)

    Wang, Chang-Zheng; Han, Hai-Hao; Tang, Xin-Ying; Zhou, Dong-Ming; Wu, Changfeng; Chen, Guo-Rong; He, Xiao-Peng; Tian, He

    2017-08-02

    The seasonal outbreak of influenza causes significant morbidity and mortality worldwide because a number of influenza virus (IV) strains have been shown to infect and circulate in humans. Development of effective means to timely monitor as well as block IVs is still a challenging task. Whereas conventional fluorescence probes rely on a fluorimetric change upon recognizing IVs, here we developed simple "Supra-dots" that are formed through the aqueous supramolecular assembly between a blue-emitting polymer dot and red-emitting sialylglycan probes for the ratiometric detection of IVs. Tuning the Förster resonance energy transfer from polymer dots to glycan probes by selective sialylglycan-virus recognition enables the fluorescence ratiometric determination of IVs, whereas the presence of unselective, control viruses quenched the fluorescence of the Supra-dots. Meanwhile, we show that the Supra-dots can effectively inhibit the invasion of a human-infecting IV toward a human cell line, thereby making possible a unique bifunctional, supramolecular probe for influenza theranostics.

  7. Preparation and characterization of water-soluble ZnSe:Cu/ZnS core/shell quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Lei; Cao, Lixin, E-mail: caolixin@ouc.edu.cn; Su, Ge; Liu, Wei; Xia, Chenghui; Zhou, Huajian

    2013-09-01

    The synthesis and luminescent properties of water-soluble ZnSe:Cu/ZnS core/shell quantum dots (QDs) with different shell thickness are reported in this paper. X-ray powder diffraction (XRD) studies present that the ZnSe:Cu/ZnS core/shell QDs with different shell thickness have a cubic zinc-blende structure. The tests of transmission electron microscope (TEM) pictures exhibit that the QDs obtained are spherical-shaped particles and the average grain size increased from 2.7 to 3.8 nm with the growth of ZnS shell. The emission peak position of QDs has a small redshift from 461 to 475 nm with the growth of ZnS shell within the blue spectral window. The photoluminescence (PL) emission intensity and stability of the ZnSe:Cu core d-dots are both enhanced by coating ZnS shell on the surface of core d-dots. The largest PL intensity of the core/shell QDs is almost 3 times larger than that of Cu doped ZnSe quantum dots (ZnSe:Cu d-dots). The redshift of core/shell QDs compared with the core QDs are observed in both the absorption and the photoluminescence excitation spectra.

  8. Approach to team skills training

    International Nuclear Information System (INIS)

    Koontz, J.L.; Roe, M.L.; Gaddy, C.D.

    1987-01-01

    The US commercial nuclear power industry has recognized the importance of team skills in control room operation. The desire to combine training of team interaction skills, like communications, with technical knowledge of reactor operations requires a unique approach to training. An NRC-sponsored study identified a five-phase approach to team skills training designed to be consistent with the systems approach to training currently endorsed by the NRC Policy Statement on Training and Qualification. This paper describes an approach to team skills training with emphasis on the nuclear power plant control room crew. An approach to team skills training

  9. Leadership by Confidence in Teams

    OpenAIRE

    Kobayashi, Hajime; Suehiro, Hideo

    2008-01-01

    We study endogenous signaling by analyzing a team production problem with endogenous timing. Each agent of the team is privately endowed with some level of confidence about team productivity. Each of them must then commit a level of effort in one of two periods. At the end of each period, each agent observes his partner' s move in this period. Both agents are rewarded by a team output determined by team productivity and total invested effort. Each agent must personally incur the cost of effor...

  10. Professional Team Foundation Server 2010

    CERN Document Server

    Blankenship, Ed; Holliday, Grant; Keller, Brian

    2011-01-01

    Authoritative guide to TFS 2010 from a dream team of Microsoft insiders and MVPs!Microsoft Visual Studio Team Foundation Server (TFS) has evolved until it is now an essential tool for Microsoft?s Application Lifestyle Management suite of productivity tools, enabling collaboration within and among software development teams. By 2011, TFS will replace Microsoft?s leading source control system, VisualSourceSafe, resulting in an even greater demand for information about it. Professional Team Foundation Server 2010, written by an accomplished team of Microsoft insiders and Microsoft MVPs, provides

  11. Starbursts in Blue compact dwarf galaxies

    International Nuclear Information System (INIS)

    Thuan, T.X.

    1987-01-01

    We summarize all the arguments for a bursting mode of star formation in blue compact dwarf galaxies. We show in particular how spectral synthesis of far ultraviolet spectra of Blue compact dwarf galaxy constitutes a powerful way for studying the star formation history in these galaxies. Blue compact dwarf galaxy luminosity functions show jumps and discontinuities. These jumps act like fossil records of the star-forming bursts, helping us to count and date the bursts

  12. Geothermal Technologies Program Blue Ribbon Panel Recommendations

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2011-06-17

    The Geothermal Technologies Program assembled a geothermal Blue Ribbon Panel on March 22-23, 2011 in Albuquerque, New Mexico for a guided discussion on the future of geothermal energy in the United States and the role of the DOE Program. The Geothermal Blue Ribbon Panel Report captures the discussions and recommendations of the experts. An addendum is available here: http://www.eere.energy.gov/geothermal/pdfs/gtp_blue_ribbon_panel_report_addendum10-2011.pdf

  13. The Pale Blue Dot: Utilizing Real World Globes in High School and Undergraduate Oceanography Classrooms

    Science.gov (United States)

    Rogers, D. B.

    2017-12-01

    Geoscience classrooms have benefitted greatly from the use of interactive, dry-erasable globes to supplement instruction on topics that require three-dimensional visualization, such as seismic wave propagation and the large-scale movements of tectonic plates. Indeed, research by Bamford (2013) demonstrates that using three-dimensional visualization to illustrate complex processes enhances student comprehension. While some geoscience courses tend to bake-in lessons on visualization, other disciplines of earth science that require three-dimensional visualization, such as oceanography, tend to rely on students' prior spatial abilities. In addition to spatial intelligence, education on the three-dimensional structure of the ocean requires knowledge of the external processes govern the behavior of the ocean, as well as the vertical and lateral distribution of water properties around the globe. Presented here are two oceanographic activities that utilize RealWorldGlobes' dry-erase globes to supplement traditional oceanography lessons on thermohaline and surface ocean circulation. While simultaneously promoting basic plotting techniques, mathematical calculations, and unit conversions, these activities touch on the processes that govern global ocean circulation, the principles of radiocarbon dating, and the various patterns exhibited by surface ocean currents. These activities challenge students to recognize inherent patterns within their data and synthesize explanations for their occurrence. Spatial visualization and critical thinking are integral to any geoscience education, and the combination of these abilities with engaging hands-on activities has the potential to greatly enhance oceanography education in both secondary and postsecondary settings

  14. The Blue Dot Workshop: Spectroscopic Search for Life on Extrasolar Planets

    Science.gov (United States)

    Des Marais, David J. (Editor)

    1997-01-01

    This workshop explored the key questions and challenges associated with detecting life on an extrasolar planet. The final product will be a NASA Conference Publication which includes the abstracts from 21 talks, summaries of key findings, and recommendations for future research. The workshop included sessions on three related topics: the biogeochemistry of biogenic gases in the atmosphere, the chemistry and spectroscopy of planetary atmospheres, and the remote sensing of planetary atmospheres and surfaces. With the observation that planetary formation is probably a common phenomenon, together with the advent of the technical capability to locate and describe extrasolar planets, this research area indeed has an exciting future.

  15. Leading Teams of Higher Education Administrators: Integrating Goal Setting, Team Role, and Team Life Cycle Theories

    Science.gov (United States)

    Posthuma, Richard; Al-Riyami, Said

    2012-01-01

    Leaders of higher education institutions can create top management teams of academic administrators to guide and improve their organizations. This study illustrates how the leadership of top management teams can be accomplished successfully through a combination of goal setting (Doran, 1981; Locke & Latham, 1990), understanding of team roles…

  16. Stark shifting two-electron quantum dot

    International Nuclear Information System (INIS)

    Dineykhan, M.; Zhaugasheva, S.A.; Duysebaeva, K.S.

    2003-01-01

    Advances in modern technology make it possible to create semiconducting nano-structures (quantum dot) in which a finite number of electrons are 'captured' in a bounded volume. A quantum dot is associated with a quantum well formed at the interface, between two finite-size semiconductors owing to different positions of the forbidden gaps on the energy scale in these semiconductors. The possibility of monitoring and controlling the properties of quantum dots attracts considerable attention to these objects, as a new elemental basis for future generations of computers. The quantum-mechanical effects and image potential play a significant role in the description of the formation mechanism quantum dot, and determined the confinement potential in a two-electron quantum dot only for the spherical symmetric case. In the present talk, we considered the formation dynamics of two-electron quantum dot with violation of spherical symmetry. So, we have standard Stark potential. The energy spectrum two-electron quantum dot were calculated. Usually Stark interactions determined the tunneling phenomena between quantum dots

  17. Quantum Dots Coupled to a Superconductor

    DEFF Research Database (Denmark)

    Jellinggaard, Anders Robert

    are tuned electrostatically. This includes tuning the odd occupation of the dot through a quantum phase transition, where it forms a singlet with excitations in the superconductor. We detail the fabrication of these bottom gated devices, which additionally feature ancillary sensor dots connected...

  18. Detecting the chirality for coupled quantum dots

    International Nuclear Information System (INIS)

    Cao Huijuan; Hu Lian

    2008-01-01

    We propose a scheme to detect the chirality for a system consisting of three coupled quantum dots. The chirality is found to be determined by the frequency of the transition between chiral states under the chiral symmetry broken perturbation. The results are important to construct quantum gates and to demonstrate chiral entangle states in the triangle spin dots

  19. Optical Properties of Semiconductor Quantum Dots

    NARCIS (Netherlands)

    Perinetti, U.

    2011-01-01

    This thesis presents different optical experiments performed on semiconductor quantum dots. These structures allow to confine a small number of electrons and holes to a tiny region of space, some nm across. The aim of this work was to study the basic properties of different types of quantum dots

  20. Optical anisotropy in vertically coupled quantum dots

    DEFF Research Database (Denmark)

    Yu, Ping; Langbein, Wolfgang Werner; Leosson, Kristjan

    1999-01-01

    We have studied the polarization of surface and edge-emitted photoluminescence (PL) from structures with vertically coupled In0.5Ga0.5As/GaAs quantum dots (QD's) grown by molecular beam epitaxy. The PL polarization is found to be strongly dependent on the number of stacked layers. While single...... number due to increasing dot size....

  1. Thick-shell nanocrystal quantum dots

    Science.gov (United States)

    Hollingsworth, Jennifer A [Los Alamos, NM; Chen, Yongfen [Eugene, OR; Klimov, Victor I [Los Alamos, NM; Htoon, Han [Los Alamos, NM; Vela, Javier [Los Alamos, NM

    2011-05-03

    Colloidal nanocrystal quantum dots comprising an inner core having an average diameter of at least 1.5 nm and an outer shell, where said outer shell comprises multiple monolayers, wherein at least 30% of the quantum dots have an on-time fraction of 0.80 or greater under continuous excitation conditions for a period of time of at least 10 minutes.

  2. Optical Spectroscopy Of Charged Quantum Dot Molecules

    Science.gov (United States)

    Scheibner, M.; Bracker, A. S.; Stinaff, E. A.; Doty, M. F.; Gammon, D.; Ponomarev, I. V.; Reinecke, T. L.; Korenev, V. L.

    2007-04-01

    Coupling between two closely spaced quantum dots is observed by means of photoluminescence spectroscopy. Hole coupling is realized by rational crystal growth and heterostructure design. We identify molecular resonances of different excitonic charge states, including the important case of a doubly charged quantum dot molecule.

  3. Capture, relaxation and recombination in quantum dots

    NARCIS (Netherlands)

    Sreenivasan, D.

    2008-01-01

    Quantum dots (QDs) have attracted a lot of interest both from application and fundamental physics point of view. A semiconductor quantum dot features discrete atomiclike energy levels, despite the fact that it contains many atoms within its surroundings. The discrete energy levels give rise to very

  4. Team-based global organizations

    DEFF Research Database (Denmark)

    Zander, Lena; Butler, Christina; Mockaitis, Audra

    2015-01-01

    diversity in enhancing team creativity and performance, and 2) the sharing of knowledge in team-based organizations, while the other two themes address global team leadership: 3) the unprecedented significance of social capital for the success of global team leader roles; and 4) the link between shared......This chapter draws on a panel discussion of the future of global organizing as a team-based organization at EIBA 2014 in Uppsala, Sweden. We began by discussing contemporary developments of hybrid forms of hierarchy and teams-based organizing, but we venture to propose that as organizations become...... characterized by decreased importance of hierarchal structures, more fluidity across borders, even a possible dissolution of firm boundaries, we move towards team-based organizing as an alternative to more traditional forms of hierarchical-based organizing in global firms. To provide input for a discussion...

  5. Team errors: definition and taxonomy

    International Nuclear Information System (INIS)

    Sasou, Kunihide; Reason, James

    1999-01-01

    In error analysis or error management, the focus is usually upon individuals who have made errors. In large complex systems, however, most people work in teams or groups. Considering this working environment, insufficient emphasis has been given to 'team errors'. This paper discusses the definition of team errors and its taxonomy. These notions are also applied to events that have occurred in the nuclear power industry, aviation industry and shipping industry. The paper also discusses the relations between team errors and Performance Shaping Factors (PSFs). As a result, the proposed definition and taxonomy are found to be useful in categorizing team errors. The analysis also reveals that deficiencies in communication, resource/task management, excessive authority gradient, excessive professional courtesy will cause team errors. Handling human errors as team errors provides an opportunity to reduce human errors

  6. Variable blue straggler stars in NGC 5466

    International Nuclear Information System (INIS)

    Harris, H.C.; Mateo, M.; Olszewski, E.W.; Nemec, J.M.

    1990-01-01

    Nine variable blue stragglers have been found in the globular cluster NGC 5466. The six dwarf Cepheids in this cluster coexist in the instability strip with other nonvariable stars. The three eclipsing binaries are among the hottest of the blue stragglers. The hypothesis is discussed that all blue stragglers in this cluster have undergone mass transfer in close binaries. Under this hypothesis, rotation and spin-down play important roles in controlling the evolution of blue stragglers in old clusters and in affecting some of their observational properties. 14 refs

  7. Why Blue-Collar Blacks Help Less

    OpenAIRE

    Smith, Sandra Susan; Young, Kara Alexis

    2013-01-01

    Why are blue-collar blacks less likely to help jobseekers than jobholders from other ethnoracial groups or even than more affluent blacks? Drawing from in-depth, semi-structured interviews with 97 black and Latino workers at one large, public sector employer, we find that blue-collar black workers both helped less proactively and rejected more requests for assistance than did blue-collar Latino and white-collar black workers. We attribute blue-collar blacks’ more passive engagement to their...

  8. Biocompatible Quantum Dots for Biological Applications

    Science.gov (United States)

    Rosenthal, Sandra J.; Chang, Jerry C.; Kovtun, Oleg; McBride, James R.; Tomlinson, Ian D.

    2011-01-01

    Semiconductor quantum dots are quickly becoming a critical diagnostic tool for discerning cellular function at the molecular level. Their high brightness, long-lasting, sizetunable, and narrow luminescence set them apart from conventional fluorescence dyes. Quantum dots are being developed for a variety of biologically oriented applications, including fluorescent assays for drug discovery, disease detection, single protein tracking, and intracellular reporting. This review introduces the science behind quantum dots and describes how they are made biologically compatible. Several applications are also included, illustrating strategies toward target specificity, and are followed by a discussion on the limitations of quantum dot approaches. The article is concluded with a look at the future direction of quantum dots. PMID:21276935

  9. Magnon-driven quantum dot refrigerators

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yuan; Huang, Chuankun; Liao, Tianjun; Chen, Jincan, E-mail: jcchen@xmu.edu.cn

    2015-12-18

    Highlights: • A three-terminal quantum dot refrigerator is proposed. • The effects of magnetic field, applied voltage, and polarization are considered. • The region that the system can work as a refrigerator is determined. • Two different magnon-driven quantum dot refrigerators are compared. - Abstract: A new model of refrigerator consisting of a spin-splitting quantum dot coupled with two ferromagnetic reservoirs and a ferromagnetic insulator is proposed. The rate equation is used to calculate the occupation probabilities of the quantum dot. The expressions of the electron and magnon currents are obtained. The region that the system can work in as a refrigerator is determined. The cooling power and coefficient of performance (COP) of the refrigerator are derived. The influences of the magnetic field, applied voltage, and polarization of two leads on the performance are discussed. The performances of two different magnon-driven quantum dot refrigerators are compared.

  10. Multi-Excitonic Quantum Dot Molecules

    Science.gov (United States)

    Scheibner, M.; Stinaff, E. A.; Doty, M. F.; Ware, M. E.; Bracker, A. S.; Gammon, D.; Ponomarev, I. V.; Reinecke, T. L.; Korenev, V. L.

    2006-03-01

    With the ability to create coupled pairs of quantum dots, the next step towards the realization of semiconductor based quantum information processing devices can be taken. However, so far little knowledge has been gained on these artificial molecules. Our photoluminescence experiments on single InAs/GaAs quantum dot molecules provide the systematics of coupled quantum dots by delineating the spectroscopic features of several key charge configurations in such quantum systems, including X, X^+,X^2+, XX, XX^+ (with X being the neutral exciton). We extract general rules which determine the formation of molecular states of coupled quantum dots. These include the fact that quantum dot molecules provide the possibility to realize various spin configurations and to switch the electron hole exchange interaction on and off by shifting charges inside the molecule. This knowledge will be valuable in developing implementations for quantum information processing.

  11. Cheap Talk: “Team Factors and Management Practices Influence on Team Trust”

    OpenAIRE

    Doris Padmini Selvaratnam; Aini Aman; Muhamad Maziz Mahyuddin Bin Kamaludin; Gary Lynn; Richard Reilly

    2016-01-01

    Team trust has been cited as a contributing factor towards team performance. This paper looks at the antecedents of team trust and to what extent they influence team trust. The antecedents of team trust are team factors like team autonomy, team stability and team member experience; and the management practices are top management involvement and management support. The results demonstrated that team factors and management practices influence team trust individually. The key find...

  12. The Fictional Black Blues Figure: Blues Music and the Art of Narrative Self-Invention

    OpenAIRE

    Mack, Kimberly

    2015-01-01

    The Fictional Black Blues Figure: Blues Music and the Art of Narrative Self-Invention, Kimberly MackMy dissertation examines representations of black American blues musicians in contemporary American fiction, drama, and popular music, and it argues that blues music can be examined as a narrative art rooted in the tradition of fictionalized autobiographical self-fashioning. I contend that the contemporary, multi-racial, literary and musical characters in my project who participate in so-called...

  13. A computational study of dimers and trimers of nitrosyl hydride: Blue shift of NH bonds that are involved in H-bond and orthogonal interactions

    Energy Technology Data Exchange (ETDEWEB)

    Solimannejad, Mohammad, E-mail: m-solimannejad@araku.ac.ir [Quantum Chemistry Group, Department of Chemistry, Arak University, 38156-879 Arak (Iran, Islamic Republic of); Massahi, Shokofeh [Quantum Chemistry Group, Department of Chemistry, Arak University, 38156-879 Arak (Iran, Islamic Republic of); Alkorta, Ibon, E-mail: ibon@iqm.csic.es [Instituto de Quimica Medica (CSIC), Juan de la Cierva, 3, 28006 Madrid (Spain)

    2009-07-30

    Ab initio calculations at MP2/aug-cc-pVTZ level were used to analyze the interactions between nitrosyl hydride (HNO) dimers and trimers. The structures obtained have been analyzed with the Atoms in Molecules (AIMs) and Natural Bond Orbital (NBO) methodologies. Four minima were located on the potential energy surface of the dimers. Nine different structures have been obtained for the trimers. Three types of interactions are observed, NH{center_dot}{center_dot}{center_dot}N and NH{center_dot}{center_dot}{center_dot}O hydrogen bonds and orthogonal interaction between the lone pair of the oxygen with the electron-deficient region of the nitrogen atom. Stabilization energies of dimers and trimers including BSSE and ZPE are in the range 4-8 kJ mol{sup -1} and 12-19 kJ mol{sup -1}, respectively. Blue shift of NH bond upon complex formation in the ranges between 30-80 and 14,114 cm{sup -1} is predicted for dimers and trimers, respectively.

  14. Electron transport in quantum dots

    CERN Document Server

    2003-01-01

    When I was contacted by Kluwer Academic Publishers in the Fall of 200 I, inviting me to edit a volume of papers on the issue of electron transport in quantum dots, I was excited by what I saw as an ideal opportunity to provide an overview of a field of research that has made significant contributions in recent years, both to our understanding of fundamental physics, and to the development of novel nanoelectronic technologies. The need for such a volume seemed to be made more pressing by the fact that few comprehensive reviews of this topic have appeared in the literature, in spite of the vast activity in this area over the course of the last decade or so. With this motivation, I set out to try to compile a volume that would fairly reflect the wide range of opinions that has emerged in the study of electron transport in quantum dots. Indeed, there has been no effort on my part to ensure any consistency between the different chapters, since I would prefer that this volume instead serve as a useful forum for the...

  15. Individual and team performance in team-handball: a review.

    Science.gov (United States)

    Wagner, Herbert; Finkenzeller, Thomas; Würth, Sabine; von Duvillard, Serge P

    2014-12-01

    Team handball is a complex sport game that is determined by the individual performance of each player as well as tactical components and interaction of the team. The aim of this review was to specify the elements of team-handball performance based on scientific studies and practical experience, and to convey perspectives for practical implication. Scientific studies were identified via data bases of PubMed, Web of Knowledge, SPORT Discus, Google Scholar, and Hercules. A total of 56 articles met the inclusion criteria. In addition, we supplemented the review with 13 additional articles, proceedings and book sections. It was found that the specific characteristics of team-handball with frequent intensity changes, team-handball techniques, hard body confrontations, mental skills and social factors specify the determinants of coordination, endurance, strength and cognition. Although we found comprehensive studies examining individual performance in team-handball players of different experience level, sex or age, there is a lack of studies, particularly for team-handball specific training, as well as cognition and social factors. Key PointsThe specific characteristics of team-handball with frequent intensity changes, specific skills, hard body confrontations, mental skills and social factors define the determinants of coordination, endurance, strength and cognition.To increase individual and team performance in team-handball specific training based on these determinants have been suggested.Although there are comprehensive studies examining individual performance in team-handball players of different experience level, sex, or age are published, there is a lack of training studies, particularly for team-handball specific techniques and endurance, as well as cognition and social factors.

  16. Reduction of blue tungsten oxide

    International Nuclear Information System (INIS)

    Wilken, T.; Wert, C.; Woodhouse, J.; Morcom, W.

    1975-01-01

    A significant portion of commercial tungsten is produced by hydrogen reduction of oxides. Although several modes of reduction are possible, hydrogen reduction is used where high purity tungsten is required and where the addition of other elements or compounds is desired for modification of the metal, as is done for filaments in the lamp industry. Although several investigations of the reduction of oxides have been reported (1 to 5), few principles have been developed which can aid in assessment of current commercial practice. The reduction process was examined under conditions approximating commercial practice. The specific objectives were to determine the effects of dopants, of water vapor in the reducing atmosphere, and of reduction temperature upon: (1) the rate of the reaction by which blue tungsten oxide is reduced to tungsten metal, (2) the intermediate oxides associated with reduction, and (3) the morphology of the resulting tungsten powder

  17. Inter-dot coupling effects on transport through correlated parallel

    Indian Academy of Sciences (India)

    Transport through symmetric parallel coupled quantum dot system has been studied, using non-equilibrium Green function formalism. The inter-dot tunnelling with on-dot and inter-dot Coulomb repulsion is included. The transmission coefficient and Landaur–Buttiker like current formula are shown in terms of internal states ...

  18. Quirks of dye nomenclature. 1. Evans blue.

    Science.gov (United States)

    Cooksey, C J

    2014-02-01

    The history, origin, identity, chemistry and use of Evans blue dye are described along with the first application to staining by Herbert McLean Evans in 1914. In the 1930s, the dye was marketed under the name, Evans blue dye, which was profoundly more acceptable than the ponderous chemical name.

  19. Blue jay attacks and consumes cedar waxwing

    Science.gov (United States)

    Daniel Saenz; Joshua B. Pierce

    2009-01-01

    Blue Jays (Cyanocitta cristata) are known to be common predators on bird nests (Wilcove 1985, Picman and Schriml 1994). In addition to predation on eggs and nestlings, Blue Jays occasionally prey on fledgling and adult birds (Johnson and Johnson 1976, Dubowy 1985). A majority of reports involve predation on House Sparrows (Passer domesticus) and other small birds (...

  20. The secret of the blue fog

    Science.gov (United States)

    Henrich, Oliver; Marenduzzo, Davide

    2017-04-01

    Why certain liquids turn blue when cooled was a mystery that stumped scientists for more than a century. As Oliver Henrich and Davide Marenduzzo explain, solving the secret of the “blue fog” proved to be an intellectual tour de force - and one that could lead to new types of display devices

  1. Virtual Teams and Knowledge Communication

    DEFF Research Database (Denmark)

    Lehtonen, Miikka; Kampf, Constance Elizabeth

    2014-01-01

    How does culture affect virtual teams and the knowledge communication processes in which they engage? As virtual spaces are increasingly used to support teams and establish collaboration in cross-cultural projects, the notion of cross-cultural communication can be understood as shifting from...... contextual perspective to a semiotic perspective. That is to say, although the team members are using the same vocabulary they might attach different meanings to and have different knowledge about them thus highlighting the importance of approaching virtual teams and collaboration from a semiotic perspective....... To look at how knowledge about virtual work is established in a multinational context, we interviewed members of a team that connects Finland and India. Results reveal five objects shared between the team members with varying knowledge about them. By making these differences in knowledge visible through...

  2. Metamorphic quantum dots: Quite different nanostructures

    International Nuclear Information System (INIS)

    Seravalli, L.; Frigeri, P.; Nasi, L.; Trevisi, G.; Bocchi, C.

    2010-01-01

    In this work, we present a study of InAs quantum dots deposited on InGaAs metamorphic buffers by molecular beam epitaxy. By comparing morphological, structural, and optical properties of such nanostructures with those of InAs/GaAs quantum dot ones, we were able to evidence characteristics that are typical of metamorphic InAs/InGaAs structures. The more relevant are: the cross-hatched InGaAs surface overgrown by dots, the change in critical coverages for island nucleation and ripening, the nucleation of new defects in the capping layers, and the redshift in the emission energy. The discussion on experimental results allowed us to conclude that metamorphic InAs/InGaAs quantum dots are rather different nanostructures, where attention must be put to some issues not present in InAs/GaAs structures, namely, buffer-related defects, surface morphology, different dislocation mobility, and stacking fault energies. On the other hand, we show that metamorphic quantum dot nanostructures can provide new possibilities of tailoring various properties, such as dot positioning and emission energy, that could be very useful for innovative dot-based devices.

  3. Roles in Innovative Software Teams

    DEFF Research Database (Denmark)

    Aaen, Ivan

    2010-01-01

    With inspiration from role-play and improvisational theater, we are developing a framework for innovation in software teams called Essence. Based on agile principles, Essence is designed for teams of developers and an onsite customer. This paper reports from teaching experiments inspired by design...... science, where we tried to assign differentiated roles to team members. The experiments provided valuable insights into the design of roles in Essence. These insights are used for redesigning how roles are described and conveyed in Essence....

  4. New lenses on team learning

    DEFF Research Database (Denmark)

    Musaeus, Peter

    Team læring er sjældent blevet studeret fra et sociokulturelt perspektiv (vygotskiansk). Denne poster er et teoretisk bidrag til team læring, der fokuserer på dialog, tegn-mediering og kulturel historisk praksis for at udvikle en forståelse af team læring som mere end forøgelse i adfærd, viden og...

  5. Team Training through Communications Control

    Science.gov (United States)

    1982-02-01

    training * operational environment * team training research issues * training approach * team communications * models of operator beharior e...on the market soon, it certainly would be investigated carefully for its applicability to the team training problem. ce A text-to-speech voice...generation system. Votrax has recently marketed such a device, and others may soon follow suit. ’ d. A speech replay system designed to produce speech from

  6. Team performance: Pitfalls and solutions

    International Nuclear Information System (INIS)

    Lee, R.R.; Eckert, M.J.

    1988-01-01

    Team building is often used as a focal point and process for improving performance. In many cases these efforts are successful in achieving the desired goals and the team building is confirmed as an effective approach. The authors have been involved in a number of successful, and some unsuccessful, efforts. This paper is concerned primarily with those cases where a team approach did not achieve the desired improvement. These experiences offer an opportunity to better understand the conditions under which team building works and to identify how a complete assessment of the prevailing conditions can provide corrections to improve the probability of success

  7. Commodity team motivation and performance

    DEFF Research Database (Denmark)

    Englyst, Linda; Jørgensen, Frances; Johansen, John

    2008-01-01

    In this article, an in-depth single case study is presented in order to explore and discuss the functioning of commodity teams in a global sourcing context. Specifically, the study aimed at identifying factors that may influence team members' motivation to participate in activities that create...... opportunities for synergy and coordination of purchasing. In the teams studied, motivation appeared to be influenced to some degree by a number of factors, including rewards, leadership behaviours, goal setting, and the career goals of the commodity team members. In some cases, inconsistencies between...

  8. Commodity Team Motivation and Performance

    DEFF Research Database (Denmark)

    Englyst, Linda; Jørgensen, Frances; Johansen, John

    2008-01-01

    In this article, an in-depth single case study is presented in order to explore and discuss the functioning of commodity teams in a global sourcing context. Specifically, the study aimed at identifying factors that may influence team members' motivation to participate in activities that create...... opportunities for synergy and coordination of purchasing. In the teams studied, motivation appeared to be influenced to some degree by a number of factors, including rewards, leadership behaviours, goal setting, and the career goals of the commodity team members. In some cases, inconsistencies between...

  9. Red Teaming: Past and Present

    National Research Council Canada - National Science Library

    Longbine, David F

    2008-01-01

    .... Key aspects of the Army red teaming definition are its emphasis on independent thinking, challenging organizational thinking, incorporating alternative perspectives, and incorporating alternative analysis...

  10. Investigating Team Learning in a Military Context

    Science.gov (United States)

    Veestraeten, Marlies; Kyndt, Eva; Dochy, Filip

    2014-01-01

    As teams have become fundamental parts of today's organisations, the need for these teams to function and learn efficiently and effectively is widely emphasised. Also in military contexts team learning is vital. The current article examines team learning behaviour in military teams as it aims to cross-validate a team learning model that was…

  11. Co-registration of fluorescence diffuse optical tomography (fDOT) with positron emission tomography (PET) and development of multi-angle fDOT

    International Nuclear Information System (INIS)

    Tong, X.

    2012-01-01

    This thesis concerns the image processing of fluorescence diffuse optical tomography (fDOT), following two axes: fDOT image co-registration with PET (positron emission tomography) image and improvement of fDOT image reconstructions using mirrors to collect additional projections. It is presented in two parts:In the first part, an automatic method to co-register the fDOT images with PET images has been developed to correlate all the information from each modality. This co-registration method is based on automatic detection of fiducial markers (FM) present in both modalities. The particularity of this method is the use of optical surface image obtained in fDOT imaging system, which serves to identify the Z position of FM in optical images. We tested this method on a model of mice bearing tumor xenografts of MEN2A cancer cells that mimic a human medullary thyroid carcinoma, after a double injection of radiotracer [ 18 F] 2-fluoro-2-Deoxy-D-glucose (FDG) for PET imaging and optical fluorescent infrared tracer Sentidye. With the accuracy of our method, we can demonstrate that the signal of Sentidye is present both in the tumor and surrounding vessels.The fDOT reconstruction image quality is degraded along the Z axis due to a limited number of projections for reconstruction. In the second part, the work is oriented towards a new method of fDOT image reconstruction with a new multi-angle data acquisition system in placing two mirrors on each side of the animal. This work was conducted in collaboration with the CS Department of University College London (UCL), a partner of the European project FMT-XCT. TOAST software developed by this team was used as source code for the reconstruction algorithm, and was modified to adapt to the concerned problem. After several tests on the adjustment of program parameters, we applied this method on a phantom that simulating the biological tissue and on mice. The results showed an improvement in the reconstructed image of a semi

  12. Nanocrystalline-Si-dot multi-layers fabrication by chemical vapor deposition with H-plasma surface treatment and evaluation of structure and quantum confinement effects

    Directory of Open Access Journals (Sweden)

    Daisuke Kosemura

    2014-01-01

    Full Text Available 100-nm-thick nanocrystalline silicon (nano-Si-dot multi-layers on a Si substrate were fabricated by the sequential repetition of H-plasma surface treatment, chemical vapor deposition, and surface oxidation, for over 120 times. The diameter of the nano-Si dots was 5–6 nm, as confirmed by both the transmission electron microscopy and X-ray diffraction analysis. The annealing process was important to improve the crystallinity of the nano-Si dot. We investigated quantum confinement effects by Raman spectroscopy and photoluminescence (PL measurements. Based on the experimental results, we simulated the Raman spectrum using a phenomenological model. Consequently, the strain induced in the nano-Si dots was estimated by comparing the experimental and simulated results. Taking the estimated strain value into consideration, the band gap modulation was measured, and the diameter of the nano-Si dots was calculated to be 5.6 nm by using PL. The relaxation of the q ∼ 0 selection rule model for the nano-Si dots is believed to be important to explain both the phenomena of peak broadening on the low-wavenumber side observed in Raman spectra and the blue shift observed in PL measurements.

  13. 49 CFR 40.13 - How do DOT drug and alcohol tests relate to non-DOT tests?

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 1 2010-10-01 2010-10-01 false How do DOT drug and alcohol tests relate to non... TRANSPORTATION WORKPLACE DRUG AND ALCOHOL TESTING PROGRAMS Employer Responsibilities § 40.13 How do DOT drug and... non-DOT drug and alcohol testing programs. This prohibition includes the use of the DOT forms with...

  14. Project Blue: Optical Coronagraphic Imaging Search for Terrestrial-class Exoplanets in Alpha Centauri

    Science.gov (United States)

    Morse, Jon; Project Blue team

    2018-01-01

    Project Blue is a coronagraphic imaging space telescope mission designed to search for habitable worlds orbiting the nearest Sun-like stars in the Alpha Centauri system. With a 45-50 cm baseline primary mirror size, Project Blue will perform a reconnaissance of the habitable zones of Alpha Centauri A and B in blue light and one or two longer wavelength bands to determine the hue of any planets discovered. Light passing through the off-axis telescope feeds into a coronagraphic instrument that forms the heart of the mission. Various coronagraph designs are being considered, such as phase induced amplitude apodization (PIAA), vector vortex, etc. Differential orbital image processing techniques will be employed to analyze the data for faint planets embedded in the residual glare of the parent star. Project Blue will advance our knowledge about the presence or absence of terrestrial-class exoplanets in the habitable zones and measure the brightness of zodiacal dust around each star, which will aid future missions in planning their observational surveys of exoplanets. It also provides on-orbit demonstration of high-contrast coronagraphic imaging technologies and techniques that will be useful for planning and implementing future space missions by NASA and other space agencies. We present an overview of the science goals, mission concept and development schedule. As part of our cooperative agreement with NASA, the Project Blue team intends to make the data available in a publicly accessible archive.

  15. On the Evolution of Helium in Blue Compact Galaxies

    International Nuclear Information System (INIS)

    Fields, B.D.; Olive, K.A.

    1998-01-01

    We discuss the chemical evolution of dwarf irregular and blue compact galaxies in light of recent data, new stellar yields, and chemical evolution models. We examine the abundance data for evidence of H ii region self-enrichment effects, which would lead to correlations in the scatter of helium, nitrogen, and oxygen abundances around their mean trends. The observed helium abundance trends show no such correlations, although the nitrogen-oxygen trend does show strong evidence for real scatter beyond observational error. We construct simple models for the chemical evolution of these galaxies, using the most recent yields of 4 He, C, N, and O in intermediate- and high-mass stars. The effects of galactic outflows, which can arise both from bulk heating and evaporation of the interstellar medium and from the partial escape of enriched supernova ejecta are included. In agreement with other studies, we find that supernova-enriched outflows can roughly reproduce the observed He, C, N, and O trends; however, in models that fit N versus O, the slopes ΔY/ΔO and ΔY/ΔN consistently fall more than 2 σ below the fit to observations. We discuss the role of the models and their uncertainties in the extrapolation of primordial helium from the data. We also explore the model dependence arising from nucleosynthesis uncertainties associated with nitrogen yields in intermediate-mass stars, the fate of 8 endash 11 M circle-dot stars, and massive star winds. copyright copyright 1998. The American Astronomical Society

  16. Quantum dot devices for optical communications

    DEFF Research Database (Denmark)

    Mørk, Jesper

    2005-01-01

    -low threshold currents and amplifiers with record-high power levels. In this tutorial we will review the basic properties of quantum dots, emphasizing the properties which are important for laser and amplifier applications, as well as devices for all-optical signal processing. The high-speed properties....... The main property of semiconductor quantum dots compared to bulk material or even quantum well structures is the discrete nature of the allowed states, which means that inversion of the medium can be obtained for very low electron densities. This has led to the fabrication of quantum dot lasers with record...

  17. Micromagnetic simulations of submicron cobalt dots

    International Nuclear Information System (INIS)

    Parker, G. J.; Cerjan, C.

    2000-01-01

    Numerical simulations of submicron Co extruded elliptical dots were performed to illustrate the relative importance of different physical parameters on the switching behavior in the easy direction. Shape, size, magnetic moment magnitude, and the magnitude and distribution of the crystalline anisotropicity were varied. The simulation represents magnetostatic, exchange, and crystalline anisotropicity fields on a structured mesh using finite difference techniques. The smooth boundary of the dots is accurately represented by use of the embedded curve boundary method. Agreement with experimental hysteresis measurements of submicron dot arrays is obtained when an appropriate angular distribution of the grain anisotropicity axes is invoked. (c) 2000 American Institute of Physics

  18. Entangled exciton states in quantum dot molecules

    Science.gov (United States)

    Bayer, Manfred

    2002-03-01

    Currently there is strong interest in quantum information processing(See, for example, The Physics of Quantum Information, eds. D. Bouwmeester, A. Ekert and A. Zeilinger (Springer, Berlin, 2000).) in a solid state environment. Many approaches mimic atomic physics concepts in which semiconductor quantum dots are implemented as artificial atoms. An essential building block of a quantum processor is a gate which entangles the states of two quantum bits. Recently a pair of vertically aligned quantum dots has been suggested as optically driven quantum gate(P. Hawrylak, S. Fafard, and Z. R. Wasilewski, Cond. Matter News 7, 16 (1999).)(M. Bayer, P. Hawrylak, K. Hinzer, S. Fafard, M. Korkusinski, Z.R. Wasilewski, O. Stern, and A. Forchel, Science 291, 451 (2001).): The quantum bits are individual carriers either on dot zero or dot one. The different dot indices play the same role as a "spin", therefore we call them "isospin". Quantum mechanical tunneling between the dots rotates the isospin and leads to superposition of these states. The quantum gate is built when two different particles, an electron and a hole, are created optically. The two particles form entangled isospin states. Here we present spectrocsopic studies of single self-assembled InAs/GaAs quantum dot molecules that support the feasibility of this proposal. The evolution of the excitonic recombination spectrum with varying separation between the dots allows us to demonstrate coherent tunneling of carriers across the separating barrier and the formation of entangled exciton states: Due to the coupling between the dots the exciton states show a splitting that increases with decreasing barrier width. For barrier widths below 5 nm it exceeds the thermal energy at room temperature. For a given barrier width, we find only small variations of the tunneling induced splitting demonstrating a good homogeneity within a molecule ensemble. The entanglement may be controlled by application of electromagnetic field. For

  19. Leadership for Team Learning: The Case of University Teacher Teams

    Science.gov (United States)

    Koeslag-Kreunen, Mieke G. M.; Van der Klink, Marcel R.; Van den Bossche, Piet; Gijselaers, Wim H.

    2018-01-01

    Teacher team involvement is considered a key factor in achieving sustainable innovation in higher education. This requires engaging in team learning behaviors that should result in new knowledge and solutions. However, university teachers are not used to discussing their work practices with one another and tend to neglect any innovation in their…

  20. Practice effects on intra-team synergies in football teams.

    Science.gov (United States)

    Silva, Pedro; Chung, Dante; Carvalho, Thiago; Cardoso, Tiago; Davids, Keith; Araújo, Duarte; Garganta, Júlio

    2016-04-01

    Developing synchronised player movements for fluent competitive match play is a common goal for coaches of team games. An ecological dynamics approach advocates that intra-team synchronization is governed by locally created information, which specifies shared affordances responsible for synergy formation. To verify this claim we evaluated coordination tendencies in two newly-formed teams of recreational players during association football practice games, weekly, for fifteen weeks (thirteen matches). We investigated practice effects on two central features of synergies in sports teams - dimensional compression and reciprocal compensation here captured through near in-phase modes of coordination and time delays between coupled players during forward and backwards movements on field while attacking and defending. Results verified that synergies were formed and dissolved rapidly as a result of the dynamic creation of informational properties, perceived as shared affordances among performers. Practising once a week led to small improvements in the readjustment delays between co-positioning team members, enabling faster regulation of coordinated team actions. Mean values of the number of player and team synergies displayed only limited improvements, possibly due to the timescales of practice. No relationship between improvements in dimensional compression and reciprocal compensation were found for number of shots, amount of ball possession and number of ball recoveries made. Findings open up new perspectives for monitoring team coordination processes in sport. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. The impact of team and work characteristics on team functioning

    NARCIS (Netherlands)

    Molleman, E.; Slomp, J.

    2006-01-01

    In this article, the authors seek to strengthen the theoretical foundation of team and cell formation through the inclusion of human factors. They distinguish three types of team characteristics: global, shared, and compositional attributes. In this last category, they also deal with diversity in

  2. Facilitating Team Cognition : How designers mirror what NPD teams do

    NARCIS (Netherlands)

    Stompff, G.

    2012-01-01

    Products are developed by large multi-disciplinary teams. The teams deal with many topics requiring the expertise of several specialists simultaneously. They have to decide together if something is a problem; propose multi-disciplinary solutions; and align their activities into a seamless whole.

  3. Stimulating teachers’ team performance through team-oriented HR practices

    NARCIS (Netherlands)

    Bouwmans, Machiel; Runhaar, Piety; Wesselink, Renate; Mulder, Martin

    2017-01-01

    Teams of teachers are increasingly held accountable for the quality of education and educational reforms in vocational education and training institutions. However, historically teachers have not been required to engage in deep-level collaboration, thus team-oriented HR practices are being used

  4. Diversity in goal orientation, team reflexivity, and team performance

    NARCIS (Netherlands)

    Pieterse, Anne Nederveen; van Knippenberg, Daan; van Ginkel, Wendy P.

    Although recent research highlights the role of team member goal orientation in team functioning, research has neglected the effects of diversity in goal orientation. In a laboratory study with groups working on a problem-solving task, we show that diversity in learning and performance orientation

  5. The innovative rehabilitation team: an experiment in team building.

    Science.gov (United States)

    Halstead, L S; Rintala, D H; Kanellos, M; Griffin, B; Higgins, L; Rheinecker, S; Whiteside, W; Healy, J E

    1986-06-01

    This article describes an effort by one rehabilitation team to create innovative approaches to team care in a medical rehabilitation hospital. The major arena for implementing change was the weekly patient rounds. We worked to increase patient involvement, developed a rounds coordinator role, used a structured format, and tried to integrate research findings into team decision making. Other innovations included use of a preadmission questionnaire, a discharge check list, and a rounds evaluation questionnaire. The impact of these changes was evaluated using the Group Environment Scale and by analyzing participation in rounds based on verbatim transcripts obtained prior to and 20 months after formation of the Innovative Rehabilitation Team (IRT). The results showed decreased participation by medical personnel during rounds, and increased participation by patients. The rounds coordinator role increased participation rates of staff from all disciplines and the group environment improved within the IRT. These data are compared with similar evaluations made of two other groups, which served as control teams. The problems inherent in making effective, lasting changes in interdisciplinary rehabilitation teams are reviewed, and a plea is made for other teams to explore additional ways to use the collective creativity and resources latent in the team membership.

  6. Circularly organized quantum dot nanostructures of Ge on Si substrates

    International Nuclear Information System (INIS)

    Cai, Qijia; Chen, Peixuan; Zhong, Zhenyang; Jiang, Zuimin; Lu, Fang; An, Zhenghua

    2009-01-01

    A novel circularly arranged structure of germanium quantum dots has been fabricated by combining techniques including electron beam lithography, wet etching and molecular beam epitaxy. It was observed that both pattern and growth parameters affect the morphology of the quantum dot molecules. Meanwhile, the oxidation mask plays a vital role in the formation of circularly organized quantum dots. The experimental results demonstrate the possibilities of investigating the properties of quantum dot molecules as well as single quantum dots

  7. A 2x2 quantum dot array with controllable inter-dot tunnel couplings

    OpenAIRE

    Mukhopadhyay, Uditendu; Dehollain, Juan Pablo; Reichl, Christian; Wegscheider, Werner; Vandersypen, Lieven M. K.

    2018-01-01

    The interaction between electrons in arrays of electrostatically defined quantum dots is naturally described by a Fermi-Hubbard Hamiltonian. Moreover, the high degree of tunability of these systems make them a powerful platform to simulate different regimes of the Hubbard model. However, most quantum dot array implementations have been limited to one-dimensional linear arrays. In this letter, we present a square lattice unit cell of 2$\\times$2 quantum dots defined electrostatically in a AlGaA...

  8. Thermoelectric transport through quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Merker, Lukas Heinrich

    2016-06-30

    In this thesis the thermoelectric properties (electrical conductance, Seebeck coefficient and thermal conductance)of quantum dots described by the Anderson impurity model have been investigated by using the numerical renormalization group (NRG) method. In order to make accurate calculations for thermoelectric properties of quantum impurity systems, a number of recent developments and refinements of the NRG have been implemented. These include the z-averaging and Campo discretization scheme, which enable the evaluation of physical quantities on an arbitrary temperature grid and at large discretization parameter Λ and the full density matrix (FDM) approach, which allows a more accurate calculation of spectral functions and transport coefficients. The implementation of the z-averaging and Campo discretization scheme has been tested within a new method for specific heats of quantum impurities. The accuracy of this new method was established by comparison with the numerical solution of the Bethe-ansatz equations for the Anderson model. The FDM approach was implemented and tested within a new approach to the calculation of impurity contributions to the uniform susceptibilities. Within this method a non-negligible contribution from the ''environmental'' degrees of freedom needs to be taken into account to recover the correct susceptibility, as shown by comparison with the Bethe-ansatz approach. An accurate method to calculate the conductance of a quantum dot is implemented, enabling the extraction of the Fermi liquid scaling coefficients c{sub T} and c{sub B} to high accuracy, being able to verify the results of the renormalized super perturbation theory approach (within its regime of validity). The method was generalized to higher order moments of the local level spectral function. This, as well as reduction of the SU(2) code to the U(1) symmetry, enabled the investigation of the effect of a magnetic field on the thermoelectric properties of quantum

  9. Chiral Responsive Liquid Quantum Dots.

    Science.gov (United States)

    Zhang, Jin; Ma, Junkai; Shi, Fangdan; Tian, Demei; Li, Haibing

    2017-08-01

    How to convert the weak chiral-interaction into the macroscopic properties of materials remains a huge challenge. Here, this study develops highly fluorescent, selectively chiral-responsive liquid quantum dots (liquid QDs) based on the hydrophobic interaction between the chiral chains and the oleic acid-stabilized QDs, which have been designated as (S)-1810-QDs. The fluorescence spectrum and liquidity of thermal control demonstrate the fluorescence properties and the fluidic behavior of (S)-1810-QDs in the solvent-free state. Especially, (S)-1810-QDs exhibit a highly chiral-selective response toward (1R, 2S)-2-amino-1,2-diphenyl ethanol. It is anticipated that this study will facilitate the construction of smart chiral fluidic sensors. More importantly, (S)-1810-QDs can become an attractive material for chiral separation. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Ultra-sensitive and selective Hg{sup 2+} detection based on fluorescent carbon dots

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Ruihua; Li, Haitao; Kong, Weiqian; Liu, Juan [Institute of Functional Nano and Soft Materials (FUNSOM) and Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Soochow University, Suzhou 215123 (China); Liu, Yang, E-mail: yangl@suda.edu.cn [Institute of Functional Nano and Soft Materials (FUNSOM) and Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Soochow University, Suzhou 215123 (China); Tong, Cuiyan, E-mail: tongcy959@nenu.edu.cn [Chemisty Department, Northeast Normal University, Changchun 130024 (China); Zhang, Xing [Institute of Functional Nano and Soft Materials (FUNSOM) and Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Soochow University, Suzhou 215123 (China); Kang, Zhenhui, E-mail: zhkang@suda.edu.cn [Institute of Functional Nano and Soft Materials (FUNSOM) and Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Soochow University, Suzhou 215123 (China)

    2013-07-15

    Graphical abstract: Fluorescent carbon dots were efficiently synthesized by one-step sodium hydroxide-assisted reflux method from PEG and demonstrated to show high selectivity toward Hg2+ ions detection. - Highlights: • FCDs were synthesized by one-step sodium hydroxide-assisted reflux method from PEG. • The FCDs emit blue photoluminescence and have upconversion fluorescent property. • The FCDs show ultra-sensitive detective ability for Hg{sup 2+} ions. - Abstract: Fluorescent carbon dots (FCDs) were efficiently synthesized by one-step sodium hydroxide-assisted reflux method from poly(ethylene glycol) (PEG). The obtained FCDs exhibit excellent water-solubility and high stability. Under the UV irradiation, the FCDs could emit bright blue photoluminescence, and also they were found to show excellent up-conversion fluorescence. It was further demonstrated that such FCDs can serve as effective fluorescent sensing platform for Hg{sup 2+} ions detection with ultra-sensitivity and selectivity. The sensing system achieved a limit of detection as low as 1 fM, which is much lower than all the previous reported sensing systems for Hg{sup 2+} ions detection. This FCDs sensing system has been successfully applied for the analysis of Hg{sup 2+} ions in water samples from river, lake, and tap water, showing good practical feasibility.

  11. Tapered photonic crystal fibers for blue-enhanced supercontinuum generation

    DEFF Research Database (Denmark)

    Møller, Uffe; Sørensen, Simon Toft; Larsen, Casper

    2012-01-01

    Tapering of photonic crystal fibers is an effective way of shifting the blue edge of a supercontinuum spectrum down in the deep-blue. We discuss the optimum taper profile for enhancing the power in the blue edge....

  12. Basketball Teams as Strategic Networks

    Science.gov (United States)

    Fewell, Jennifer H.; Armbruster, Dieter; Ingraham, John; Petersen, Alexander; Waters, James S.

    2012-01-01

    We asked how team dynamics can be captured in relation to function by considering games in the first round of the NBA 2010 play-offs as networks. Defining players as nodes and ball movements as links, we analyzed the network properties of degree centrality, clustering, entropy and flow centrality across teams and positions, to characterize the game from a network perspective and to determine whether we can assess differences in team offensive strategy by their network properties. The compiled network structure across teams reflected a fundamental attribute of basketball strategy. They primarily showed a centralized ball distribution pattern with the point guard in a leadership role. However, individual play-off teams showed variation in their relative involvement of other players/positions in ball distribution, reflected quantitatively by differences in clustering and degree centrality. We also characterized two potential alternate offensive strategies by associated variation in network structure: (1) whether teams consistently moved the ball towards their shooting specialists, measured as “uphill/downhill” flux, and (2) whether they distributed the ball in a way that reduced predictability, measured as team entropy. These network metrics quantified different aspects of team strategy, with no single metric wholly predictive of success. However, in the context of the 2010 play-offs, the values of clustering (connectedness across players) and network entropy (unpredictability of ball movement) had the most consistent association with team advancement. Our analyses demonstrate the utility of network approaches in quantifying team strategy and show that testable hypotheses can be evaluated using this approach. These analyses also highlight the richness of basketball networks as a dataset for exploring the relationships between network structure and dynamics with team organization and effectiveness. PMID:23139744

  13. Basketball teams as strategic networks.

    Science.gov (United States)

    Fewell, Jennifer H; Armbruster, Dieter; Ingraham, John; Petersen, Alexander; Waters, James S

    2012-01-01

    We asked how team dynamics can be captured in relation to function by considering games in the first round of the NBA 2010 play-offs as networks. Defining players as nodes and ball movements as links, we analyzed the network properties of degree centrality, clustering, entropy and flow centrality across teams and positions, to characterize the game from a network perspective and to determine whether we can assess differences in team offensive strategy by their network properties. The compiled network structure across teams reflected a fundamental attribute of basketball strategy. They primarily showed a centralized ball distribution pattern with the point guard in a leadership role. However, individual play-off teams showed variation in their relative involvement of other players/positions in ball distribution, reflected quantitatively by differences in clustering and degree centrality. We also characterized two potential alternate offensive strategies by associated variation in network structure: (1) whether teams consistently moved the ball towards their shooting specialists, measured as "uphill/downhill" flux, and (2) whether they distributed the ball in a way that reduced predictability, measured as team entropy. These network metrics quantified different aspects of team strategy, with no single metric wholly predictive of success. However, in the context of the 2010 play-offs, the values of clustering (connectedness across players) and network entropy (unpredictability of ball movement) had the most consistent association with team advancement. Our analyses demonstrate the utility of network approaches in quantifying team strategy and show that testable hypotheses can be evaluated using this approach. These analyses also highlight the richness of basketball networks as a dataset for exploring the relationships between network structure and dynamics with team organization and effectiveness.

  14. Basketball teams as strategic networks.

    Directory of Open Access Journals (Sweden)

    Jennifer H Fewell

    Full Text Available We asked how team dynamics can be captured in relation to function by considering games in the first round of the NBA 2010 play-offs as networks. Defining players as nodes and ball movements as links, we analyzed the network properties of degree centrality, clustering, entropy and flow centrality across teams and positions, to characterize the game from a network perspective and to determine whether we can assess differences in team offensive strategy by their network properties. The compiled network structure across teams reflected a fundamental attribute of basketball strategy. They primarily showed a centralized ball distribution pattern with the point guard in a leadership role. However, individual play-off teams showed variation in their relative involvement of other players/positions in ball distribution, reflected quantitatively by differences in clustering and degree centrality. We also characterized two potential alternate offensive strategies by associated variation in network structure: (1 whether teams consistently moved the ball towards their shooting specialists, measured as "uphill/downhill" flux, and (2 whether they distributed the ball in a way that reduced predictability, measured as team entropy. These network metrics quantified different aspects of team strategy, with no single metric wholly predictive of success. However, in the context of the 2010 play-offs, the values of clustering (connectedness across players and network entropy (unpredictability of ball movement had the most consistent association with team advancement. Our analyses demonstrate the utility of network approaches in quantifying team strategy and show that testable hypotheses can be evaluated using this approach. These analyses also highlight the richness of basketball networks as a dataset for exploring the relationships between network structure and dynamics with team organization and effectiveness.

  15. Team work on international projects

    International Nuclear Information System (INIS)

    Hayfield, F.

    1983-01-01

    A successful team will result in Project efficiency and so lead to a better achievement of the Project objectives. Such a team will be self-motivating and have a high level of morale. An effective team will also create a better context for transfer of know-how and so better prepare its members for greater roles on future Project teams. The nature of Project work forces the process of team building to recognize several facts of life. A Project team can have a life as short as one year and as long as ten years. A team usually consists of people on temporary transfer from different departments yet retaining a link of some sort to their departments of origin. It may consist of members of one company only or of several as in a joint-venture and may include Client personnel. On International Projects, the members of a team may have different nationalities and be working in a language foreign to many of them. Many of the Project people may be expatriates to the Project area on a bachelor or on a married status well away from their head or usual office. Team building is a complex organizational and human process, with no mathematical formula for the ideal solution. It starts with the selection of the right Project Manager who should be a leader, a technocrat manager and an integrator all at the same time. The Project Manager must have the authority to create the organizational and human climate that will motivate to a maximum each member of the team. Each member must understand clearly his role and realize that this contribution to the Project will influence his career development. Loyalty to the Project Manager must be possible and the Departmental Manager has to recognize this necessity. This presentation will indicate the basic steps of a team building process on a typical major international Project

  16. Phonon impact on optical control schemes of quantum dots: Role of quantum dot geometry and symmetry

    Science.gov (United States)

    Lüker, S.; Kuhn, T.; Reiter, D. E.

    2017-12-01

    Phonons strongly influence the optical control of semiconductor quantum dots. When modeling the electron-phonon interaction in several theoretical approaches, the quantum dot geometry is approximated by a spherical structure, though typical self-assembled quantum dots are strongly lens-shaped. By explicitly comparing simulations of a spherical and a lens-shaped dot using a well-established correlation expansion approach, we show that, indeed, lens-shaped dots can be exactly mapped to a spherical geometry when studying the phonon influence on the electronic system. We also give a recipe to reproduce spectral densities from more involved dots by rather simple spherical models. On the other hand, breaking the spherical symmetry has a pronounced impact on the spatiotemporal properties of the phonon dynamics. As an example we show that for a lens-shaped quantum dot, the phonon emission is strongly concentrated along the direction of the smallest axis of the dot, which is important for the use of phonons for the communication between different dots.

  17. Harmonic generations in a lens-shaped GaAs quantum dot: Dresselhaus and Rashba spin-orbit couplings under electric and magnetic fields

    Science.gov (United States)

    Zamani, A.; Azargoshasb, T.; Niknam, E.; Mohammadhosseini, E.

    2017-06-01

    In this work, effects of external electric and magnetic fields in the presence of both Rashba and Dresselhaus spin-orbit couplings on the second and third harmonic generations (SHG and THG) of a lens-shaped GaAs quantum dot are studied. Energy eigenvalues and eigenvectors are calculated numerically and optical properties are obtained using the compact density matrix approach. Our results reveal that, an increase in the magnetic field, leads to both red and blue shifts in resonant peaks of both SHG and THG. On the other hand, augmentation of electric field leads to blue shift in all resonant peaks except the first peak related to lowest transition. Also the dipole moment matrix elements increase by enhancing both electric and magnetic fields. Finally the effect of dot size is studied and results illustrate that increment in size reduces the transition energies except the lowest one and thus leads to red shift in resonant peaks while the first peak remains constant.

  18. One pot synthesis of highly luminescent polyethylene glycol anchored carbon dots functionalized with a nuclear localization signal peptide for cell nucleus imaging.

    Science.gov (United States)

    Yang, Lei; Jiang, Weihua; Qiu, Lipeng; Jiang, Xuewei; Zuo, Daiying; Wang, Dongkai; Yang, Li

    2015-04-14

    Strong blue fluorescent polyethylene glycol (PEG) anchored carbon nitride dots (CDs@PEG) with a high quantum yield (QY) of 75.8% have been synthesized by a one step hydrothermal treatment. CDs with a diameter of ca. 6 nm are well dispersed in water and present a graphite-like structure. Photoluminescence (PL) studies reveal that CDs display excitation-dependent behavior and are stable under various test conditions. Based on the as-prepared CDs, we designed novel cell nucleus targeting imaging carbon dots functionalized with a nuclear localization signal (NLS) peptide. The favourable biocompatibilities of CDs and NLS modified CDs (NLS-CDs) are confirmed by in vitro cytotoxicity assays. Importantly, intracellular localization experiments in MCF7 and A549 cells demonstrate that NLS-CDs could be internalized in the nucleus and show blue light, which indicates that CDs may serve as cell nucleus imaging probes.

  19. Developing team cognition: A role for simulation

    Science.gov (United States)

    Fernandez, Rosemarie; Shah, Sachita; Rosenman, Elizabeth D.; Kozlowski, Steve W. J.; Parker, Sarah Henrickson; Grand, James A.

    2016-01-01

    SUMMARY STATEMENT Simulation has had a major impact in the advancement of healthcare team training and assessment. To date, the majority of simulation-based training and assessment focuses on the teamwork behaviors that impact team performance, often ignoring critical cognitive, motivational, and affective team processes. Evidence from team science research demonstrates a strong relationship between team cognition and team performance and suggests a role for simulation in the development of this team-level construct. In this article we synthesize research from the broader team science literature to provide foundational knowledge regarding team cognition and highlight best practices for using simulation to target team cognition. PMID:28704287

  20. Can greening of aquaculture sequester blue carbon?

    Science.gov (United States)

    Ahmed, Nesar; Bunting, Stuart W; Glaser, Marion; Flaherty, Mark S; Diana, James S

    2017-05-01

    Globally, blue carbon (i.e., carbon in coastal and marine ecosystems) emissions have been seriously augmented due to the devastating effects of anthropogenic pressures on coastal ecosystems including mangrove swamps, salt marshes, and seagrass meadows. The greening of aquaculture, however, including an ecosystem approach to Integrated Aquaculture-Agriculture (IAA) and Integrated Multi-Trophic Aquaculture (IMTA) could play a significant role in reversing this trend, enhancing coastal ecosystems, and sequestering blue carbon. Ponds within IAA farming systems sequester more carbon per unit area than conventional fish ponds, natural lakes, and inland seas. The translocation of shrimp culture from mangrove swamps to offshore IMTA could reduce mangrove loss, reverse blue carbon emissions, and in turn increase storage of blue carbon through restoration of mangroves. Moreover, offshore IMTA may create a barrier to trawl fishing which in turn could help restore seagrasses and further enhance blue carbon sequestration. Seaweed and shellfish culture within IMTA could also help to sequester more blue carbon. The greening of aquaculture could face several challenges that need to be addressed in order to realize substantial benefits from enhanced blue carbon sequestration and eventually contribute to global climate change mitigation.

  1. Data Teams for School Improvement

    Science.gov (United States)

    Schildkamp, Kim; Poortman, Cindy L.; Handelzalts, Adam

    2016-01-01

    The use of data for educational decision making has never been more prevalent. However, teachers and school leaders need support in data use. Support can be provided by means of professional development in the form of "data teams". This study followed the functioning of 4 data teams over a period of 2 years, applying a qualitative case…

  2. Diversity Management in Global Teams

    DEFF Research Database (Denmark)

    Clausen, Lisbeth

    2016-01-01

    implemented in the local organization? How are organizational culture, vision and images aligned with the team processes to accomplish the task? Does professional (functional) expertise influence team collaboration and finally how do individual experiences and coping strategies matter? The US and Japan...

  3. Team Teaching. IDEA Paper #55

    Science.gov (United States)

    Plank, Kathryn M.

    2013-01-01

    Team teaching has the potential to have a profound impact on both teaching and learning. Many who have taught as part of a team report the break from solitary practice brings renewed excitement for teaching and the course that makes them better teachers. It also creates a learning environment in which students can explore multiple perspectives and…

  4. The Benefits of Team Teaching.

    Science.gov (United States)

    Morganti, Deena J.; Buckalew, Flora C.

    1991-01-01

    Discussion of team teaching focuses on librarians team teaching a course on information search strategy at the Pennsylvania State Berks Campus Library. Course requirements are described, planning for the course is discussed, grading practices are reviewed, and course and instructor evaluations are described. (two references) (LRW)

  5. Improving supervision: a team approach.

    Science.gov (United States)

    1993-01-01

    This issue of "The Family Planning Manager" outlines an interactive team supervision strategy as a means of improving family planning service quality and enabling staff to perform to their maximum potential. Such an approach to supervision requires a shift from a monitoring to a facilitative role. Because supervisory visits to the field are infrequent, the regional supervisor, clinic manager, and staff should form a team to share ongoing supervisory responsibilities. The team approach removes individual blame and builds consensus. An effective team is characterized by shared leadership roles, concrete work problems, mutual accountability, an emphasis on achieving team objectives, and problem resolution within the group. The team supervision process includes the following steps: prepare a visit plan and schedule; meet with the clinic manager and staff to explain how the visit will be conducted; supervise key activity areas (clinical, management, and personnel); conduct a problem-solving team meeting; conduct a debriefing meeting with the clinic manager; and prepare a report on the visit, including recommendations and follow-up plans. In Guatemala's Family Planning Unit, teams identify problem areas on the basis of agreement that a problem exists, belief that the problem can be solved with available resources, and individual willingness to accept responsibility for the specific actions identified to correct the problem.

  6. Multicolor fluorescent light-emitting diodes based on cesium lead halide perovskite quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Peng [State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, Changchun 130012 (China); State Key Laboratory of Superhard Materials, College of Physics, Jilin University, Changchun 130012 (China); Bai, Xue, E-mail: baix@jlu.edu.cn, E-mail: yuzhang@jlu.edu.cn; Sun, Chun; Zhang, Xiaoyu; Zhang, Yu, E-mail: baix@jlu.edu.cn, E-mail: yuzhang@jlu.edu.cn [State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, Changchun 130012 (China); Zhang, Tieqiang [State Key Laboratory of Superhard Materials, College of Physics, Jilin University, Changchun 130012 (China)

    2016-08-08

    High quantum yield, narrow full width at half-maximum and tunable emission color of perovskite quantum dots (QDs) make this kind of material good prospects for light-emitting diodes (LEDs). However, the relatively poor stability under high temperature and air condition limits the device performance. To overcome this issue, the liquid-type packaging structure in combination with blue LED chip was employed to fabricate the fluorescent perovskite quantum dot-based LEDs. A variety of monochromatic LEDs with green, yellow, reddish-orange, and red emission were fabricated by utilizing the inorganic cesium lead halide perovskite quantum dots as the color-conversion layer, which exhibited the narrow full width at half-maximum (<35 nm), the relatively high luminous efficiency (reaching 75.5 lm/W), and the relatively high external quantum efficiency (14.6%), making it the best-performing perovskite LEDs so far. Compared to the solid state LED device, the liquid-type LED devices exhibited excellent color stability against the various working currents. Furthermore, we demonstrated the potential prospects of all-inorganic perovskite QDs for the liquid-type warm white LEDs.

  7. Interband emission energy in a dilute nitride quaternary semiconductor quantum dot for longer wavelength applications

    Science.gov (United States)

    Mageshwari, P. Uma; Peter, A. John; Lee, Chang Woo; Duque, C. A.

    2016-07-01

    Excitonic properties are studied in a strained Ga1-xInxNyAs1-y/GaAs cylindrical quantum dot. The optimum condition for the desired band alignment for emitting wavelength 1.55 μm is investigated using band anticrossing model and the model solid theory. The band gap and the band discontinuities of a Ga1-xInxNyAs1-y/GaAs quantum dot on GaAs are computed with the geometrical confinement effect. The binding energy of the exciton, the oscillator strength and its radiative life time for the optimum condition are found taking into account the spatial confinement effect. The effects of geometrical confinement and the nitrogen incorporation on the interband emission energy are brought out. The result shows that the desired band alignment for emitting wavelength 1.55 μm is achieved for the inclusion of alloy contents, y=0.0554% and x=0.339% in Ga1-xInxNyAs1-y/GaAs quantum dot. And the incorporation of nitrogen and indium shows the red-shift and the geometrical confinement shows the blue-shift. And it can be applied for fibre optical communication networks.

  8. Multicolor fluorescent light-emitting diodes based on cesium lead halide perovskite quantum dots

    International Nuclear Information System (INIS)

    Wang, Peng; Bai, Xue; Sun, Chun; Zhang, Xiaoyu; Zhang, Yu; Zhang, Tieqiang

    2016-01-01

    High quantum yield, narrow full width at half-maximum and tunable emission color of perovskite quantum dots (QDs) make this kind of material good prospects for light-emitting diodes (LEDs). However, the relatively poor stability under high temperature and air condition limits the device performance. To overcome this issue, the liquid-type packaging structure in combination with blue LED chip was employed to fabricate the fluorescent perovskite quantum dot-based LEDs. A variety of monochromatic LEDs with green, yellow, reddish-orange, and red emission were fabricated by utilizing the inorganic cesium lead halide perovskite quantum dots as the color-conversion layer, which exhibited the narrow full width at half-maximum (<35 nm), the relatively high luminous efficiency (reaching 75.5 lm/W), and the relatively high external quantum efficiency (14.6%), making it the best-performing perovskite LEDs so far. Compared to the solid state LED device, the liquid-type LED devices exhibited excellent color stability against the various working currents. Furthermore, we demonstrated the potential prospects of all-inorganic perovskite QDs for the liquid-type warm white LEDs.

  9. Infiltrating giant cellular blue naevus.

    Science.gov (United States)

    Bittencourt, A L; Monteiro, D A; De Pretto, O J

    2007-01-01

    Cellular blue naevi (CBN) measure 1-2 cm in diameter and affect the dermis, occasionally extending into the subcutaneous fat. The case of a 14-year-old boy with a giant CBN (GCBN) involving the right half of the face, the jugal mucosa and the lower eyelid with a tumour that had infiltrated the bone and the maxillary and ethmoidal sinuses is reported. Biopsies were taken from the skin, jugal mucosa and maxillary sinus. The following markers were used in the immunohistochemical evaluation: CD34, CD56, HMB-45, anti-S100, A-103, Melan A and MIB-1. The biopsy specimens showed a biphasic pattern affecting the lower dermis, subcutaneous fat, skeletal muscle, bone, jugal mucosa and maxillary sinus, but there was no histological evidence of malignancy. The tumour cells were CD34-, CD56-, HMB45+, anti-S100+ and A-103+. Melan A was focally expressed. No positive MIB-1 cells were identified. The present case shows that GCBN may infiltrate deeply, with no evidence of malignancy.

  10. System and method for making quantum dots

    KAUST Repository

    Bakr, Osman; Pan, Jun; El-Ballouli, Ala'a O.; Knudsen, Kristian Rahbek; Abdelhady, Ahmed L.

    2015-01-01

    Embodiments of the present disclosure provide for methods of making quantum dots (QDs) (passivated or unpassivated) using a continuous flow process, systems for making QDs using a continuous flow process, and the like. In one or more embodiments

  11. MoDOT research peer exchange.

    Science.gov (United States)

    2011-04-01

    The Missouri Department of Transportation hosted a peer exchange on April 11-12, 2011 in Jefferson City, Missouri. Participants included representatives from four state DOTs, The National Academies, USDOT-RITA, FHWA, and both public and private resea...

  12. Electron Transport in Coupled Quantum Dots

    National Research Council Canada - National Science Library

    Antoniadis, D

    1998-01-01

    In the course of the investigation funded by this proposal we fabricated, modeled, and measured a variety of quantum dot structures in order to better understand how such nanostructures might be used for computation...

  13. Synthetic Developments of Nontoxic Quantum Dots.

    Science.gov (United States)

    Das, Adita; Snee, Preston T

    2016-03-03

    Semiconductor nanocrystals, or quantum dots (QDs), are candidates for biological sensing, photovoltaics, and catalysis due to their unique photophysical properties. The most studied QDs are composed of heavy metals like cadmium and lead. However, this engenders concerns over heavy metal toxicity. To address this issue, numerous studies have explored the development of nontoxic (or more accurately less toxic) quantum dots. In this Review, we select three major classes of nontoxic quantum dots composed of carbon, silicon and Group I-III-VI elements and discuss the myriad of synthetic strategies and surface modification methods to synthesize quantum dots composed of these material systems. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Optical Studies of Single Quantum Dots

    National Research Council Canada - National Science Library

    Gammon, Daniel; Steel, Duncan G

    2002-01-01

    ...: the atomlike entities known as quantum dots (QDs). Measuring 1-100 nm across, QDs are semiconductor structures in which the electron wavefunction is confined in all three dimensions by the potential energy barriers that form the QD's boundaries...

  15. The evolving DOT enterprise : today toward tomorrow.

    Science.gov (United States)

    2013-04-01

    Departments of transportation (DOTs) today are being shaped by a wide range of : factors some of which are directly managed and controlled within the transportation : industry while others are external factors shaping the demand for transportatio...

  16. Alternative energy resources for MoDOT

    Science.gov (United States)

    2011-02-01

    This research investigates environmentally friendly alternative energy sources that could be used by MoDOT in various areas, and develops applicable and sustainable strategies to implement those energy sources.

  17. Colloidal Quantum Dot Photovoltaics: A Path Forward

    KAUST Repository

    Kramer, Illan J.; Sargent, Edward H.

    2011-01-01

    spectrum. CQD materials' ease of processing derives from their synthesis, storage, and processing in solution. Rapid advances have brought colloidal quantum dot photovoltaic solar power conversion efficiencies of 6% in the latest reports. These achievements

  18. Corneal edema and permanent blue discoloration of a silicone intraocular lens by methylene blue.

    Science.gov (United States)

    Stevens, Scott; Werner, Liliana; Mamalis, Nick

    2007-01-01

    To report a silicone intraocular lens (IOL) stained blue by inadvertent intraoperative use of methylene blue instead of trypan blue and the results of experimental staining of various lens materials with different concentrations of the same dye. A "blue dye" was used to enhance visualization during capsulorhexis in a patient undergoing phacoemulsification with implantation of a three-piece silicone lens. Postoperatively, the patient presented with corneal edema and a discolored IOL. Various IOL materials were experimentally stained using methylene blue. Sixteen lenses (4 silicone, 4 hydrophobic acrylic, 4 hydrophilic acrylic, and 4 polymethylmethacrylate) were immersed in 0.5 mL of methylene blue at concentrations of 1%, 0.1%, 0.01%, and 0.001%. These lenses were grossly and microscopically evaluated for discoloration 6 and 24 hours after immersion. The corneal edema resolved within 1 month after the initial surgical procedure. After explantation, gross and microscopic analyses of the explanted silicone lens revealed that its surface and internal substance had been permanently stained blue. In the experimental study, all of the lenses except the polymethylmethacrylate lenses were permanently stained by methylene blue. The hydrophilic acrylic lenses showed the most intense blue staining in all dye concentrations. This is the first clinicopathological report of IOL discoloration due to intraocular use of methylene blue. This and other tissue dyes may be commonly found among surgical supplies in the operating room and due diligence is necessary to avoid mistaking these dyes for those commonly used during ocular surgery.

  19. One-pot fabrication of high-quality InP/ZnS (core/shell) quantum dots and their application to cellular imaging.

    Science.gov (United States)

    Hussain, Sahid; Won, Nayoun; Nam, Jutaek; Bang, Jiwon; Chung, Hyokyun; Kim, Sungjee

    2009-07-13

    True colors: High-quality InP and InP/ZnS quantum dots (QDs) are obtained by means of a simple one-pot method in the presence of polyethylene glycol (PEG). Rapid and size-controlled reactions lead to highly crystalline and nearly monodisperse QDs at relatively low temperatures. The particles emit from cyan blue to far-red, and are successfully used in cellular imaging (see figure).

  20. Long-term stable stacked CsPbBr3 quantum dot films for highly efficient white light generation in LEDs.

    Science.gov (United States)

    Song, Young Hyun; Yoo, Jin Sun; Kang, Bong Kyun; Choi, Seung Hee; Ji, Eun Kyung; Jung, Hyun Suk; Yoon, Dae Ho

    2016-12-01

    We report highly efficient ethyl cellulose with CsPbBr 3 perovskite QD films for white light generation in LED application. Ethyl cellulose with CsPbBr 3 quantum dots is applied with Sr 2 Si 5 N 8  : Eu 2+ red phosphor on an InGaN blue chip, achieving a highly efficient luminous efficacy of 67.93 lm W -1 under 20 mA current.

  1. Extra-team connections for knowledge transfer between staff teams

    Science.gov (United States)

    Ramanadhan, Shoba; Wiecha, Jean L.; Emmons, Karen M.; Gortmaker, Steven L.; Viswanath, Kasisomayajula

    2009-01-01

    As organizations implement novel health promotion programs across multiple sites, they face great challenges related to knowledge management. Staff social networks may be a useful medium for transferring program-related knowledge in multi-site implementation efforts. To study this potential, we focused on the role of extra-team connections (ties between staff members based in different site teams) as potential channels for knowledge sharing. Data come from a cross-sectional study of afterschool childcare staff implementing a health promotion program at 20 urban sites of the Young Men's Christian Association of Greater Boston. We conducted a sociometric social network analysis and attempted a census of 91 program staff members. We surveyed 80 individuals, and included 73 coordinators and general staff, who lead and support implementation, respectively, in this study. A multiple linear regression model demonstrated a positive relationship between extra-team connections (β = 3.41, P knowledge transfer. We also found that intra-team connections (within-team ties between staff members) were also positively related to skill receipt. Connections between teams appear to support knowledge transfer in this network, but likely require greater active facilitation, perhaps via organizational changes. Further research on extra-team connections and knowledge transfer in low-resource, high turnover environments is needed. PMID:19528313

  2. Silicon Quantum Dots for Quantum Information Processing

    Science.gov (United States)

    2013-11-01

    S. Lai, C. Tahan, A. Morello and A. S. Dzurak, Electron Spin lifetimes in multi-valley sil- icon quantum dots, S3NANO Winter School Few spin solid...lifetimes in multi-valley sil- icon quantum dots, International Workshop on Silicon Quantum Electronics, Grenoble, France, February 2012 (Poster). C...typically plunger gates), PMMA A5 is spun at 5000 rpm for 30 seconds, resulting in a 280 nm resist thickness. The resists are baked for 90 seconds at 180

  3. Exciton in type-II quantum dot

    Energy Technology Data Exchange (ETDEWEB)

    Sierra-Ortega, J; Escorcia, R A [Universidad del Magdalena, A. A. 731, Santa Marta (Colombia); Mikhailov, I D, E-mail: jsierraortega@gmail.co [Universidad Industrial de Santander, A. A. 678, Bucaramanga (Colombia)

    2009-05-01

    We study the quantum-size effect and the influence of the external magnetic field on the exciton ground state energy in the type-II InP quantum disk, lens and pyramid deposited on a wetting layer and embedded in a GaInP matrix. We show that the charge distribution over and below quantum dot and wetting layer induced by trapped exciton strongly depends on the quantum dot morphology and the strength of the magnetic field.

  4. NASA Blue Team: Determining Operational Security Posture of Critical Systems and Networks

    Science.gov (United States)

    Alley, Adam David

    2016-01-01

    Emergence of Cybersecurity has increased the focus on security risks to Information Technology (IT) assets going beyond traditional Information Assurance (IA) concerns: More sophisticated threats have emerged from increasing sources as advanced hacker tools and techniques have emerged and proliferated to broaden the attack surface available across globally interconnected networks.

  5. Controllable synthesis, growth mechanism and optical properties of the ZnSe quantum dots and nanoparticles with different crystalline phases

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Bo [Key Laboratory of Excited State Physics, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, 3888 Eastern Nan-Hu Road, Changchun 130033 (China); Graduate School of the Chinese Academy of Sciences, Beijing 100049 (China); Institute of Condensed State Physics, Jilin Normal University, Siping 136000 (China); Yang, Jinghai, E-mail: jhyang1@jlnu.edu.cn [Institute of Condensed State Physics, Jilin Normal University, Siping 136000 (China); Cao, Jian; Yang, Lili; Gao, Ming; Wei, Maobin; Liu, Yang [Institute of Condensed State Physics, Jilin Normal University, Siping 136000 (China); Song, Hang [Key Laboratory of Excited State Physics, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, 3888 Eastern Nan-Hu Road, Changchun 130033 (China)

    2013-03-15

    Graphical abstract: The ZnSe quantum dots (3.5 nm) with the wurtzite structure exhibited a strong near band-edge emission (NBE) peak centered at 422 nm. The zinc blende ZnSe nanoparticles (21 nm) exhibited near-band-edge luminescence peak centered at 472 nm. Highlights: ► The results of TEM showed that the ZnSe quantum dots were about 3.5 nm. ► The ZnSe quantum dots exhibited a near band-edge emission peak centered at 422 nm. ► The ZnSe nanoparticles exhibited near-band-edge luminescence peak centered at 472 nm. - Abstract: ZnSe precursors were prepared by a solvothermal method at 180 °C without any surface-active agents. ZnSe quantum dots and nanoparticles were obtained by annealing the precursors at 300 °C for 2 h in argon atmosphere. The ZnSe quantum dots were about 3.5 nm, while the ZnSe nanoparticles were about 21 nm, as observed using TEM. The growth mechanisms for the two samples were discussed; this proved that the high coordination ability of ethylenediamine to zinc played an important role in the final phase of the products. The ZnSe quantum dots with the wurtzite structure exhibited a strong near band-edge emission (NBE) peak centered at 422 nm, which was blue-shifted in comparison to that of the bulk ZnSe, which was mainly caused by the quantum confinement effect. However, the zinc blende ZnSe nanoparticles exhibited a near-band-edge luminescence peak centered at 472 nm.

  6. Sol-Gel Chemistry for Carbon Dots.

    Science.gov (United States)

    Malfatti, Luca; Innocenzi, Plinio

    2018-03-14

    Carbon dots are an emerging class of carbon-based nanostructures produced by low-cost raw materials which exhibit a widely-tunable photoluminescence and a high quantum yield. The potential of these nanomaterials as a substitute of semiconductor quantum dots in optoelectronics and biomedicine is very high, however they need a customized chemistry to be integrated in host-guest systems or functionalized in core-shell structures. This review is focused on recent advances of the sol-gel chemistry applied to the C-dots technology. The surface modification, the fine tailoring of the chemical composition and the embedding into a complex nanostructured material are the main targets of combining sol-gel processing with C-dots chemistry. In addition, the synergistic effect of the sol-gel precursor combined with the C-dots contribute to modify the intrinsic chemo-physical properties of the dots, empowering the emission efficiency or enabling the tuning of the photoluminescence over a wide range of the visible spectrum. © 2018 The Chemical Society of Japan & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Coherent transport through interacting quantum dots

    International Nuclear Information System (INIS)

    Hiltscher, Bastian

    2012-01-01

    The present thesis is composed of four different works. All deal with coherent transport through interacting quantum dots, which are tunnel-coupled to external leads. There a two main motivations for the use of quantum dots. First, they are an ideal device to study the influence of strong Coulomb repulsion, and second, their discrete energy levels can easily be tuned by external gate electrodes to create different transport regimes. The expression of coherence includes a very wide range of physical correlations and, therefore, the four works are basically independent of each other. Before motivating and introducing the different works in more detail, we remark that in all works a diagrammatic real-time perturbation theory is used. The fermionic degrees of freedom of the leads are traced out and the elements of the resulting reduced density matrix can be treated explicitly by means of a generalized master equation. How this equation is solved, depends on the details of the problem under consideration. In the first of the four works adiabatic pumping through an Aharonov-Bohm interferometer with a quantum dot embedded in each of the two arms is studied. In adiabatic pumping transport is generated by varying two system parameters periodically in time. We consider the two dot levels to be these two pumping parameters. Since they are located in different arms of the interferometer, pumping is a quantum mechanical effect purely relying on coherent superpositions of the dot states. It is very challenging to identify a quantum pumping mechanism in experiments, because a capacitive coupling of the gate electrodes to the leads may yield an undesired AC bias voltage, which is rectified by a time dependent conductance. Therefore, distinguishing features of these two transport mechanisms are required. We find that the dependence on the magnetic field is the key feature. While the pumped charge is an odd function of the magnetic flux, the rectified current is even, at least in

  8. Coherent transport through interacting quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Hiltscher, Bastian

    2012-10-05

    The present thesis is composed of four different works. All deal with coherent transport through interacting quantum dots, which are tunnel-coupled to external leads. There a two main motivations for the use of quantum dots. First, they are an ideal device to study the influence of strong Coulomb repulsion, and second, their discrete energy levels can easily be tuned by external gate electrodes to create different transport regimes. The expression of coherence includes a very wide range of physical correlations and, therefore, the four works are basically independent of each other. Before motivating and introducing the different works in more detail, we remark that in all works a diagrammatic real-time perturbation theory is used. The fermionic degrees of freedom of the leads are traced out and the elements of the resulting reduced density matrix can be treated explicitly by means of a generalized master equation. How this equation is solved, depends on the details of the problem under consideration. In the first of the four works adiabatic pumping through an Aharonov-Bohm interferometer with a quantum dot embedded in each of the two arms is studied. In adiabatic pumping transport is generated by varying two system parameters periodically in time. We consider the two dot levels to be these two pumping parameters. Since they are located in different arms of the interferometer, pumping is a quantum mechanical effect purely relying on coherent superpositions of the dot states. It is very challenging to identify a quantum pumping mechanism in experiments, because a capacitive coupling of the gate electrodes to the leads may yield an undesired AC bias voltage, which is rectified by a time dependent conductance. Therefore, distinguishing features of these two transport mechanisms are required. We find that the dependence on the magnetic field is the key feature. While the pumped charge is an odd function of the magnetic flux, the rectified current is even, at least in

  9. Semiconductor Quantum Dots with Photoresponsive Ligands.

    Science.gov (United States)

    Sansalone, Lorenzo; Tang, Sicheng; Zhang, Yang; Thapaliya, Ek Raj; Raymo, Françisco M; Garcia-Amorós, Jaume

    2016-10-01

    Photochromic or photocaged ligands can be anchored to the outer shell of semiconductor quantum dots in order to control the photophysical properties of these inorganic nanocrystals with optical stimulations. One of the two interconvertible states of the photoresponsive ligands can be designed to accept either an electron or energy from the excited quantum dots and quench their luminescence. Under these conditions, the reversible transformations of photochromic ligands or the irreversible cleavage of photocaged counterparts translates into the possibility to switch luminescence with external control. As an alternative to regulating the photophysics of a quantum dot via the photochemistry of its ligands, the photochemistry of the latter can be controlled by relying on the photophysics of the former. The transfer of excitation energy from a quantum dot to a photocaged ligand populates the excited state of the species adsorbed on the nanocrystal to induce a photochemical reaction. This mechanism, in conjunction with the large two-photon absorption cross section of quantum dots, can be exploited to release nitric oxide or to generate singlet oxygen under near-infrared irradiation. Thus, the combination of semiconductor quantum dots and photoresponsive ligands offers the opportunity to assemble nanostructured constructs with specific functions on the basis of electron or energy transfer processes. The photoswitchable luminescence and ability to photoinduce the release of reactive chemicals, associated with the resulting systems, can be particularly valuable in biomedical research and can, ultimately, lead to the realization of imaging probes for diagnostic applications as well as to therapeutic agents for the treatment of cancer.

  10. Model of Team Organization and Behavior and Team Description Method

    Science.gov (United States)

    1984-10-01

    PERFORMING ORG& REPORT’ NUMBER 7.AUTHIOR(&) 0. CONTRACT OR GRANT NUMOSR(ej J. Thomas Roth Rohn J. Hritz HDA 903-81-C-0198: VEa Donald W. McGill 9...team descriptions are included, acid procedures for data recording are provided. 4q-4 4 iv, G OP S• . . • ,," $1 . . ’ __ _ _ _ ’ / . • , Utilization...Listing of thi! number acid identification of the roles adopted by team members in the actual team structure, along with KOS and primary equipment

  11. On the diameter of dot-critical graphs

    Directory of Open Access Journals (Sweden)

    Doost Ali Mojdeh

    2009-01-01

    Full Text Available A graph G is \\(k\\-dot-critical (totaly \\(k\\-dot-critical if \\(G\\ is dot-critical (totaly dot-critical and the domination number is \\(k\\. In the paper [T. Burtona, D. P. Sumner, Domination dot-critical graphs, Discrete Math, 306 (2006, 11-18] the following question is posed: What are the best bounds for the diameter of a \\(k\\-dot-critical graph and a totally \\(k\\-dot-critical graph \\(G\\ with no critical vertices for \\(k \\geq 4\\? We find the best bound for the diameter of a \\(k\\-dot-critical graph, where \\(k \\in\\{4,5,6\\}\\ and we give a family of \\(k\\-dot-critical graphs (with no critical vertices with sharp diameter \\(2k-3\\ for even \\(k \\geq 4\\.

  12. Quantum measurement of coherent tunneling between quantum dots

    International Nuclear Information System (INIS)

    Wiseman, H. M.; Utami, Dian Wahyu; Sun, He Bi; Milburn, G. J.; Kane, B. E.; Dzurak, A.; Clark, R. G.

    2001-01-01

    We describe the conditional and unconditional dynamics of two coupled quantum dots when one dot is subjected to a measurement of its occupation number by coupling it to a third readout dot via the Coulomb interaction. The readout dot is coupled to source and drain leads under weak bias, and a tunnel current flows through a single bound state when energetically allowed. The occupation of the quantum dot near the readout dot shifts the bound state of the readout dot from a low conducting state to a high conducting state. The measurement is made by continuously monitoring the tunnel current through the readout dot. We show that there is a difference between the time scale for the measurement-induced decoherence between the localized states of the dots, and the time scale on which the system becomes localized due to the measurement

  13. Harnessing members' positive mood for team-directed learning behaviour and team innovation : The moderating role of perceived team feedback

    NARCIS (Netherlands)

    Walter, Frank; van der Vegt, Gerben S.

    2013-01-01

    This study examines the role of individual team members' positive mood and perceived team feedback for their team-directed learning behaviour. Results obtained in a sample of 186 members from 27 work teams showed that positive mood was positively associated with team-directed learning behaviour if

  14. Substantial Research Secures the Blue Future for our Blue Plant

    Directory of Open Access Journals (Sweden)

    Moustafa Abdel Maksoud

    2016-06-01

    Full Text Available Earth, the blue planet, is our home, and seas and oceans cover more than 70% of its surface. As the earth’s population rapidly increases and available resources decrease, seas and oceans can play a key role in assuring the long-term survival of humankind. Renewable maritime energy has huge potential to provide a considerable part of the earth’s population with decarbonised electricity generation systems. Renewable maritime energy is very flexible and can be harvested above the water’s free surface by using offshore wind turbines, on the water’s surface by using wave energy converters or below the water’s surface by using current or tidal turbines. The supposed conflict between environmental protection measures and economic interests is neither viable nor reasonable. Renewable maritime energy can be the motor for considerable substantial economic growth for many maritime regions and therefore for society at large. The fastest growing sector of renewable maritime energy is offshore wind. The annual report of the European Wind Energy Association from the year 2015 confirms the growing relevance of the offshore wind industry. In 2015, the total installed and grid-connected capacity of wind power was 12,800 MW in the EU and 6,013.4 MW in Germany. 38% of the 2015 annual installation in Germany was offshore, accounting for a capacity of 2,282.4 MW. However, there are a limited number of available installation sites in shallow water, meaning that there is an urgent need to develop new offshore structures for water depths greater than 50m. The persistent trend towards deeper waters has encouraged the offshore wind industry to look for floating wind turbine structures and larger turbines. Floating wind turbine technologies are at an early stage of development and many technical and economic challenges will still need to be faced. Nonetheless, intensive research activities and the employment of advanced technologies are the key factors in

  15. High-luminosity blue and blue-green gallium nitride light-emitting diodes.

    Science.gov (United States)

    Morkoç, H; Mohammad, S N

    1995-01-06

    Compact and efficient sources of blue light for full color display applications and lighting eluded and tantalized researchers for many years. Semiconductor light sources are attractive owing to their reliability and amenability to mass manufacture. However, large band gaps are required to achieve blue color. A class of compound semiconductors formed by metal nitrides, GaN and its allied compounds AIGaN and InGaN, exhibits properties well suited for not only blue and blue-green emitters, but also for ultraviolet emitters and detectors. What thwarted engineers and scientists from fabricating useful devices from these materials in the past was the poor quality of material and lack of p-type doping. Both of these obstacles have recently been overcome to the point where highluminosity blue and blue-green light-emitting diodes are now available in the marketplace.

  16. The Biology of blue-green algae

    National Research Council Canada - National Science Library

    Carr, Nicholas G; Whitton, B. A

    1973-01-01

    .... Their important environmental roles, their part in nitrogen fixation and the biochemistry of phototrophic metabolism are some of the attractions of blue-geen algae to an increasing number of biologists...

  17. BLUES function method in computational physics

    Science.gov (United States)

    Indekeu, Joseph O.; Müller-Nedebock, Kristian K.

    2018-04-01

    We introduce a computational method in physics that goes ‘beyond linear use of equation superposition’ (BLUES). A BLUES function is defined as a solution of a nonlinear differential equation (DE) with a delta source that is at the same time a Green’s function for a related linear DE. For an arbitrary source, the BLUES function can be used to construct an exact solution to the nonlinear DE with a different, but related source. Alternatively, the BLUES function can be used to construct an approximate piecewise analytical solution to the nonlinear DE with an arbitrary source. For this alternative use the related linear DE need not be known. The method is illustrated in a few examples using analytical calculations and numerical computations. Areas for further applications are suggested.

  18. Nanotubes based on monolayer blue phosphorus

    KAUST Repository

    Montes Muñ oz, Enrique; Schwingenschlö gl, Udo

    2016-01-01

    We demonstrate structural stability of monolayer zigzag and armchair blue phosphorus nanotubes by means of molecular dynamics simulations. The vibrational spectrum and electronic band structure are determined and analyzed as functions of the tube

  19. Teaching Engineering Students Team Work

    Science.gov (United States)

    Levi, Daniel

    1998-01-01

    The purpose of this manual is to provide professor's in engineering classes which the background necessary to use student team projects effectively. This manual describes some of the characteristics of student teams and how to use them in class. It provides a set of class activities and films which can be used to introduce and support student teams. Finally, a set of teaching modules used in freshmen, sophomore, and senior aeronautical engineering classes are presented. This manual was developed as part of a NASA sponsored project to improve the undergraduate education of aeronautical engineers. The project has helped to purchase a set of team work films which can be checked out from Cal Poly's Learning Resources Center in the Kennedy Library. Research for this project has included literature reviews on team work and cooperative learning; interviews, observations, and surveys of Cal Poly students from Industrial and Manufacturing Engineering, Aeronautical Engineering and Psychology; participation in the Aeronautical Engineering senior design lab; and interviews with engineering faculty. In addition to this faculty manual, there is a student team work manual which has been designed to help engineering students work better in teams.

  20. Diversity in Teams: was macht diverse Teams erfolgreich?

    NARCIS (Netherlands)

    Buengeler, C.; Homan, A.C.; Genkova, P.; Ringeisen, T.

    2015-01-01

    Teams in Organisationen sind zunehmend divers zusammengesetzt. Mit Diversity sind neben Unterschieden bezüglich demografischer Merkmale beispielsweise auch Differenzen in unmittelbar aufgabenbezogenen Merkmalen sowie in Werten, Einstellungen und Eigenschaften gemeint, welche oftmals nicht sofort

  1. Poly(ethylene glycol)/carbon quantum dot composite solid films exhibiting intense and tunable blue–red emission

    International Nuclear Information System (INIS)

    Hao, Yanling; Gan, Zhixing; Xu, Jiaqing; Wu, Xinglong; Chu, Paul K.

    2014-01-01

    Highlights: • Poly(ethylene glycol)/carbon quantum dots (PEG/CQDs) composite solid films exhibiting strong and tunable blue–red emission were prepared. Successful preparation of tunable emitting CQDs solid films can extend the application of carbon quantum dots in photoelectric devices. • The mechanism of the tunable emission from the PEG/CQDs composite solid films was discussed. • On the basis of the characteristics of the PL from solid films in this work, the complex PL origins of CQDs were further defined. The PL mechanism provides insights into the fluorescence mechanism of CQDs and may promotes their applications. • Poly(ethylene glycol); carbon quantum dots; Strong and tunable blue-red emission; The fluorescent quantum yield of 12.6%. - Abstract: Although carbon quantum dots (CQDs) possess excellent luminescence properties, it is a challenge to apply water-soluble CQDs to tunable luminescent devices. Herein, quaternary CQDs are incorporated into poly(ethylene glycol) to produce poly(ethylene glycol)/CQD composite solid films which exhibit strong and tunable blue–red emission. The fluorescent quantum yield reaches 12.6% which is comparable to that of many liquid CQDs and the photoluminescence characteristics are determined to elucidate the fluorescence mechanism. The CQD solid films with tunable optical properties bode well for photoelectric devices especially displays

  2. Improvement in luminance of light-emitting diode using InP/ZnS quantum dot with 1-dodecanethiol ligand

    Science.gov (United States)

    Fukuda, Takeshi; Sasaki, Hironao

    2018-03-01

    We present the synthesis protocol of a red emissive InP/ZnS quantum dot with a 1-dodecanthiol ligand and its application to a quantum dot light-emitting diode. The ligand change from oleylamine to 1-dodecanthiol, which were connected around the InP/ZnS quantum dot, was confirmed by Fourier-transform infrared spectroscopy and thermal analysis. The absorption peak was blue-shifted by changing 1-dodecanthiol ligands from oleylamine ligands to prevent the unexpected nucleation of the InP core. In addition, the luminance of the light-emitting device was improved by using the InP/ZnS quantum dot with 1-dodecanthiol ligands, and the maximum current efficiency of 7.2 × 10-3 cd/A was achieved. The 1-dodecanthiol ligand is often used for capping to reduce the number of surface defects and/or prevent unexpected core growth, resulting in reduced Auger recombination. This result indicates that 1-dodecanthiol ligands prevent the deactivation of excitons while injecting carriers by applying a voltage, resulting in a high luminance efficiency.

  3. Ionophore-based optical nanosensors incorporating hydrophobic carbon dots and a pH-sensitive quencher dye for sodium detection.

    Science.gov (United States)

    Galyean, A A; Behr, M R; Cash, K J

    2018-01-21

    Nanosensors present a biological monitoring method that is biocompatible, reversible, and nano-scale, and they offer many advantages over traditional organic indicators. Typical ionophore-based nanosensors incorporate nile-blue derivative pH indicators but suffer from photobleaching while quantum dot alternatives pose a potential toxicity risk. In order to address this challenge, sodium selective nanosensors containing carbon dots and a pH-sensitive quencher molecule were developed based on an ion-exchange theory and a decoupled recognition element from the pH indicator. Carbon dots were synthesized and integrated into nanosensors containing a pH-indicator, an analyte-binding ligand (ionophore), and a charge-balancing additive. These nanosensors are ion-selective against potassium (selectivity coefficient of 0.4) and lithium (selectivity coefficient of 0.9). Reversible nanosensor response to sodium is also demonstrated. The carbon dot nanosensors are resistant to changes in optical properties for at least 12 h and display stable selectivity to physiologically-relevant sodium (alpha = 0.5 of 200 mM NaCl) for a minimum of 6 days.

  4. Role Allocation and Team Structure in Command and Control Teams

    Science.gov (United States)

    2014-06-01

    organizational psychology and management sciences literature show concepts such as empowered self-management and self-regulating work teams (see Cooney, 2004...tankers (FT), search units (S) and rescue units (R). Each unit is represented on the map by a numbered icon. Each type of unit is colour -coded and...Understanding team adaptation: A conceptual analysis and model. Journal of Applied Psychology , 91, 1189-1207. Cannon-Bowers, J. A., Tannenbaum

  5. Leading a Virtual Intercultural Team. Implications for Virtual Team Leaders

    OpenAIRE

    Chutnik, Monika; Grzesik, Katarzyna

    2009-01-01

    Increasing number of companies operate in the setup of teams whose members are geographically scattered and have different cultural origins. They work through access to the same digital network and communicate by means of modern technology. Sometimes they are located in different time zones and have never met each other face to face. This is the age of a virtual team leader. Virtual leadership in intercultural groups requires special skills from leaders. Many of these reflect leadership s...

  6. Tuning the Emission Energy of Chemically Doped Graphene Quantum Dots

    Directory of Open Access Journals (Sweden)

    Noor-Ul-Ain

    2016-11-01

    Full Text Available Tuning the emission energy of graphene quantum dots (GQDs and understanding the reason of tunability is essential for the GOD function in optoelectronic devices. Besides material-based challenges, the way to realize chemical doping and band gap tuning also pose a serious challenge. In this study, we tuned the emission energy of GQDs by substitutional doping using chlorine, nitrogen, boron, sodium, and potassium dopants in solution form. Photoluminescence data obtained from (Cl- and N-doped GQDs and (B-, Na-, and K-doped GQDs, respectively exhibited red- and blue-shift with respect to the photoluminescence of the undoped GQDs. X-ray photoemission spectroscopy (XPS revealed that oxygen functional groups were attached to GQDs. We qualitatively correlate red-shift of the photoluminescence with the oxygen functional groups using literature references which demonstrates that more oxygen containing groups leads to the formation of more defect states and is the reason of observed red-shift of luminescence in GQDs. Further on, time resolved photoluminescence measurements of Cl- and N-GQDs demonstrated that Cl substitution in GQDs has effective role in radiative transition whereas in N-GQDs leads to photoluminescence (PL quenching with non-radiative transition to ground state. Presumably oxidation or reduction processes cause a change of effective size and the bandgap.

  7. Multi-color single particle tracking with quantum dots.

    Directory of Open Access Journals (Sweden)

    Eva C Arnspang

    Full Text Available Quantum dots (QDs have long promised to revolutionize fluorescence detection to include even applications requiring simultaneous multi-species detection at single molecule sensitivity. Despite the early promise, the unique optical properties of QDs have not yet been fully exploited in e. g. multiplex single molecule sensitivity applications such as single particle tracking (SPT. In order to fully optimize single molecule multiplex application with QDs, we have in this work performed a comprehensive quantitative investigation of the fluorescence intensities, fluorescence intensity fluctuations, and hydrodynamic radii of eight types of commercially available water soluble QDs. In this study, we show that the fluorescence intensity of CdSe core QDs increases as the emission of the QDs shifts towards the red but that hybrid CdSe/CdTe core QDs are less bright than the furthest red-shifted CdSe QDs. We further show that there is only a small size advantage in using blue-shifted QDs in biological applications because of the additional size of the water-stabilizing surface coat. Extending previous work, we finally also show that parallel four color multicolor (MC-SPT with QDs is possible at an image acquisition rate of at least 25 Hz. We demonstrate the technique by measuring the lateral dynamics of a lipid, biotin-cap-DPPE, in the cellular plasma membrane of live cells using four different colors of QDs; QD565, QD605, QD655, and QD705 as labels.

  8. Surface effects on the photoluminescence of Si quantum dots

    International Nuclear Information System (INIS)

    Wang, Chiang-Jing; Tsai, Meng-Yen; Chi, Cheng Chung; Perng, Tsong-Pyng

    2009-01-01

    Si quantum dots (SiQDs) with sizes ranging from 5 to 20 nm were fabricated by vapor condensation. They showed red photoluminescence (PL) in vacuum with the peak located at around 750 nm. After the specimen was exposed to air, the PL intensity became higher, and continued to increase during the PL test with a cycling of vacuum-air-vacuum. In pure oxygen, the PL intensity exhibited an irreversible decrease, while in nitrogen a smaller amount of reversible increase of PL intensity was observed. Furthermore, the PL intensity exhibited a remarkable enhancement if the SiQDs were treated with water. With HF treatment, the PL peak position showed a blue-shift to 680 nm, and was recovered after subsequent exposure to air. Si-O-H complexes were suggested to be responsible for this red luminescence. The irreversible decrease of PL intensity due to oxygen adsorption was speculated to be caused by the modification of chemical bonds on the surface. In the case of nitrogen adsorption, the PL change was attributed to the surface charging during adsorption.

  9. Binding Quantum Dots to Silk Biomaterials for Optical Sensing

    Directory of Open Access Journals (Sweden)

    Disi Lu

    2015-01-01

    Full Text Available Quantum dots (QDs, have great potential for fabricating optical sensing devices and imaging biomaterial degradation in vivo. In the present study, 2-mercaptoethylamine- (MEA- and mercaptopropionic acid- (MPA- capped CdTe-QDs were physically incorporated in silk films that contained a high content (>30% of crystalline beta-sheet structure. The beta-sheets were induced by the addition of glycerol, water annealing, glycerol/annealing, or treatment with methanol. Incorporation of QDs did not influence the formation of beta-sheets. When the films were extracted with water, most QDs remained associated with the silk, based on the retention of photoluminescence in the silk films and negligible photoluminescence in the extracts. Compared to the solution state, photoluminescence intensity significantly decreased for MEA-QDs but not for MPA-QDs in the silk films, while the emission maximum blue shifted (≈4 nm slightly for both. Further film digestion using protease XIV, alpha-chymotrypsin, and the combination of the two proteases suggested that QDs may be bound to the silk beta-sheet regions but not the amorphous regions. QDs photoluminescence in silk films was quenched when the concentration of hydrogen peroxide (H2O2 was above 0.2-0.3 mM, indicating the QDs-incorporated silk films can be used to report oxidation potential in solution.

  10. Team networking in palliative care

    Directory of Open Access Journals (Sweden)

    Odette Spruyt

    2011-01-01

    Full Text Available "If you want to travel quickly, go alone. But if you want to travel far, you must go together". African proverb. The delivery of palliative care is often complex and always involves a group of people, the team, gathered around the patient and those who are close to them. Effective communication and functional responsive systems of care are essential if palliative care is to be delivered in a timely and competent way. Creating and fostering an effective team is one of the greatest challenges for providers of palliative care. Teams are organic and can be life giving or life sapping for their members.

  11. Commodity Team Motivation and Performance

    DEFF Research Database (Denmark)

    Englyst, Linda; Jørgensen, Frances; Johansen, John

    2007-01-01

    This article explores factors influencing the motivation and performance of commodity teams in a global sourcing context. Several challenges are related to the classical dilemma of matrix organization, but with particular implications in this specific context of purchasing. We report on a reward...... system which was intended to support collective team effort, yet enhanced conflicts of interest in the matrix structure, discuss leadership, goal alignment and career tracks, and debate when and whether a team structure is appropriate in the pursuit of corporate purchasing synergies. The article is based...

  12. Voluntary versus Enforced Team Effort

    Directory of Open Access Journals (Sweden)

    Claudia Keser

    2011-08-01

    Full Text Available We present a model where each of two players chooses between remuneration based on either private or team effort. Although at least one of the players has the equilibrium strategy to choose private remuneration, we frequently observe both players to choose team remuneration in a series of laboratory experiments. This allows for high cooperation payoffs but also provides individual free-riding incentives. Due to significant cooperation, we observe that, in team remuneration, participants make higher profits than in private remuneration. We also observe that, when participants are not given the option of private remuneration, they cooperate significantly less.

  13. Team Networking in Palliative Care

    Science.gov (United States)

    Spruyt, Odette

    2011-01-01

    “If you want to travel quickly, go alone. But if you want to travel far, you must go together”. African proverb. The delivery of palliative care is often complex and always involves a group of people, the team, gathered around the patient and those who are close to them. Effective communication and functional responsive systems of care are essential if palliative care is to be delivered in a timely and competent way. Creating and fostering an effective team is one of the greatest challenges for providers of palliative care. Teams are organic and can be life giving or life sapping for their members. PMID:21811361

  14. Spin interactions in InAs quantum dots and molecules

    Energy Technology Data Exchange (ETDEWEB)

    Doty, M.F.; Ware, M.E.; Stinaff, E.A.; Scheibner, M.; Bracker, A.S.; Ponomarev, I.V.; Badescu, S.C.; Reinecke, T.L.; Gammon, D. [Naval Research Lab, Washington, DC 20375 (United States); Korenev, V.L. [A.F. Ioffe Physical Technical Institute, St. Petersburg 194021 (Russian Federation)

    2006-12-15

    Spin interactions between particles in quantum dots or quantum dot molecules appear as fine structure in the photoluminescence spectra. Using the understanding of exchange interactions that has been developed from single dot spectra, we analyze the spin signatures of coupled quantum dots separated by a wide barrier such that inter-dot interactions are negligible. We find that electron-hole exchange splitting is directly evident. In dots charged with an excess hole, an effective hole-hole interaction can be turned on through tunnel coupling. (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  15. Artful and multifaceted applications of carbon dot in biomedicine.

    Science.gov (United States)

    Jaleel, Jumana Abdul; Pramod, K

    2018-01-10

    Carbon dots (C-dots) are luminescent carbon nanomaterial having good biocompatibility and low toxicity. The characteristic fluorescence emission property of C-dots establishes their role in optical imaging. C-dots which are superior to fluorescent dyes and semiconductor quantum dots act as a safer in vivo imaging probe. Apart from their bioimaging application, other applications in biomedicine such as drug delivery, cancer therapy, and gene delivery were studied. In this review, we present multifaceted applications of C-dots along with their synthesis, surface passivation, doping, and toxicity profile. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Blue space geographies: Enabling health in place.

    Science.gov (United States)

    Foley, Ronan; Kistemann, Thomas

    2015-09-01

    Drawing from research on therapeutic landscapes and relationships between environment, health and wellbeing, we propose the idea of 'healthy blue space' as an important new development Complementing research on healthy green space, blue space is defined as; 'health-enabling places and spaces, where water is at the centre of a range of environments with identifiable potential for the promotion of human wellbeing'. Using theoretical ideas from emotional and relational geographies and critical understandings of salutogenesis, the value of blue space to health and wellbeing is recognised and evaluated. Six individual papers from five different countries consider how health can be enabled in mixed blue space settings. Four sub-themes; embodiment, inter-subjectivity, activity and meaning, document multiple experiences within a range of healthy blue spaces. Finally, we suggest a considerable research agenda - theoretical, methodological and applied - for future work within different forms of blue space. All are suggested as having public health policy relevance in social and public space. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Cognitive model supported team skill training

    NARCIS (Netherlands)

    Doesburg, W.A. van; Stroomer, S.M.

    2006-01-01

    Complex tasks require coordinated performance by multiple team members. To perform the task effectively each team member must not only master the individual task component but also needs to function in the overall team. To increase team performance, each team member will need to acquire the relevant

  18. Changes of photoluminescence of electron beam irradiated self-assembled InAs/GaAs quantum dots

    Science.gov (United States)

    Maliya; Aierken, Abuduwayiti; Li, Yudong; Zhou, Dong; Zhao, Xiaofan; Guo, Qi; Liu, Chaoming

    2018-03-01

    We investigate the effects of 1.0MeV electron beam irradiation on the photoluminescence of self-assembled InAs/GaAs quantum dots. After irradiation doses up to 1×1016e-/cm2 , photoluminescence of all samples was degraded dramatically and some additional radiation-induced changes in photo-carrier recombination from QDs, which include a slight increase in PL emission with low electron doses under different photo-injection condition in two samples, are also noticed. Different energy shift was observed in two samples with different Quantum Dot sizes. We attribute this remarkable phenomenon to combination of stress relaxation induced red-shift and In-Ga intermixing caused blue-shift.

  19. Ratiometric photoluminescence sensing based on Ti3C2 MXene quantum dots as an intracellular pH sensor.

    Science.gov (United States)

    Chen, Xu; Sun, Xueke; Xu, Wen; Pan, Gencai; Zhou, Donglei; Zhu, Jinyang; Wang, He; Bai, Xue; Dong, Biao; Song, Hongwei

    2018-01-18

    Intracellular pH sensing is of importance and can be used as an indicator for monitoring the evolution of various diseases and the health of cells. Here, we developed a new class of surface-functionalized MXene quantum dots (QDs), Ti 3 C 2 , by the sonication cutting and hydrothermal approach and further explored their intracellular pH sensing. The functionalized Ti 3 C 2 QDs exhibit bright excitation-dependent blue photoluminescence (PL) originating from the size effect and surface defects. Meanwhile, Ti 3 C 2 QDs demonstrate a high PL response induced by the deprotonation of the surface defects. Furthermore, combining the highly pH sensitive Ti 3 C 2 QDs with the pH insensitive [Ru(dpp) 3 ]Cl 2 , we developed a ratiometric pH sensor to quantitatively monitor the intracellular pH values. These novel MXene quantum dots can serve as a promising platform for developing practical fluorescent nanosensors.

  20. Submonolayer Quantum Dot Infrared Photodetector

    Science.gov (United States)

    Ting, David Z.; Bandara, Sumith V.; Gunapala, Sarath D.; Chang, Yia-Chang

    2010-01-01

    A method has been developed for inserting submonolayer (SML) quantum dots (QDs) or SML QD stacks, instead of conventional Stranski-Krastanov (S-K) QDs, into the active region of intersubband photodetectors. A typical configuration would be InAs SML QDs embedded in thin layers of GaAs, surrounded by AlGaAs barriers. Here, the GaAs and the AlGaAs have nearly the same lattice constant, while InAs has a larger lattice constant. In QD infrared photodetector, the important quantization directions are in the plane perpendicular to the normal incidence radiation. In-plane quantization is what enables the absorption of normal incidence radiation. The height of the S-K QD controls the positions of the quantized energy levels, but is not critically important to the desired normal incidence absorption properties. The SML QD or SML QD stack configurations give more control of the structure grown, retains normal incidence absorption properties, and decreases the strain build-up to allow thicker active layers for higher quantum efficiency.

  1. Advancements in the Field of Quantum Dots

    Science.gov (United States)

    Mishra, Sambeet; Tripathy, Pratyasha; Sinha, Swami Prasad.

    2012-08-01

    Quantum dots are defined as very small semiconductor crystals of size varying from nanometer scale to a few micron i.e. so small that they are considered dimensionless and are capable of showing many chemical properties by virtue of which they tend to be lead at one minute and gold at the second minute.Quantum dots house the electrons just the way the electrons would have been present in an atom, by applying a voltage. And therefore they are very judiciously given the name of being called as the artificial atoms. This application of voltage may also lead to the modification of the chemical nature of the material anytime it is desired, resulting in lead at one minute to gold at the other minute. But this method is quite beyond our reach. A quantum dot is basically a semiconductor of very tiny size and this special phenomenon of quantum dot, causes the band of energies to change into discrete energy levels. Band gaps and the related energy depend on the relationship between the size of the crystal and the exciton radius. The height and energy between different energy levels varies inversely with the size of the quantum dot. The smaller the quantum dot, the higher is the energy possessed by it.There are many applications of the quantum dots e.g. they are very wisely applied to:Light emitting diodes: LEDs eg. White LEDs, Photovoltaic devices: solar cells, Memory elements, Biology : =biosensors, imaging, Lasers, Quantum computation, Flat-panel displays, Photodetectors, Life sciences and so on and so forth.The nanometer sized particles are able to display any chosen colour in the entire ultraviolet visible spectrum through a small change in their size or composition.

  2. Hydrogen Storage Technical Team Roadmap

    Energy Technology Data Exchange (ETDEWEB)

    None

    2013-06-01

    The mission of the Hydrogen Storage Technical Team is to accelerate research and innovation that will lead to commercially viable hydrogen-storage technologies that meet the U.S. DRIVE Partnership goals.

  3. Valuing gender diversity in teams

    DEFF Research Database (Denmark)

    Lauring, Jakob; Villeseche, Florence

    2015-01-01

    Team gender diversity has been much debated in many different contexts – not least since the search for a main effect of diversity on performance was launched. However, results have so far been inconclusive, and a number of scholars suggest that more attention should be directed at contextual...... factors which could influence the effect of gender diversity on team performance. In this study, we explore the effect of positive diversity attitudes and assess the degree of gender diversity where such group attitudes have greater impact. This is done by using a sample of 1085 leaders of academic...... research teams. Findings show that positive diversity attitude in the form of group openness to diversity is strongly associated with team performance. We also find a moderating effect of gender diversity meaning that the effect of openness to diversity is stronger when gender groups are more balanced...

  4. The Origins of Team Management

    Science.gov (United States)

    Swift, James S.

    1971-01-01

    An analysis of the factors that have led to team management, including classical principles of management, the human relations or behavioral school of management, and the systems theory both closed and open. (JF)

  5. Family, Team or Something Else?

    Directory of Open Access Journals (Sweden)

    John Murtha

    2017-02-01

    Full Text Available When referring to staff, is the term "family" or "team" most accurate? John Murtha explores the importance of setting a company's core value to create and maintain a positive culture, expectations, and support hiring practices.

  6. Diving and Environmental Simulation Team

    Data.gov (United States)

    Federal Laboratory Consortium — The Diving and Environmental Simulation Team focuses on ways to optimize the performance and safety of Navy divers. Our goal is to increase mission effectiveness by...

  7. SYNERGY EFFECTS IN WORK TEAMS

    Directory of Open Access Journals (Sweden)

    Raluca C. ZOLTAN

    2014-06-01

    Full Text Available Today’s organization increasingly utilizes all kind of teams in order to surpass their competitors through flexibility, adaptability and innovation, features which are seen to characterize the teams. For this purpose, the concept of synergy in teams’ activity is often mentioned as the prime reason for which collective work is considered to be superior comparative with individual work. But what exactly does it mean? The present paper aims to shed some light on the concept of synergy in work teams and its positive effects, namely, the social consequences of collective work such as social compensation, social indispensability, social comparison, social identity, but also its negative effects, such as free-riding, social loafing and sucker effect. These are important group phenomena that managers should be aware of because they have a major impact on team performance, and consequently, on organization performance.

  8. <300> GeV team

    CERN Multimedia

    CERN PhotoLab

    1971-01-01

    The 300 GeV team had been assembled. In the photograph are Hans Horisberger, Clemens Zettler, Roy Billinge, Norman Blackburne, John Adams, Hans-Otto Wuster, Lars Persson, Bas de Raad, Hans Goebel, Simon Van der Meer.

  9. Photoluminescent (PL) or electroluminescent (EL) quantum dots for display, lighting, and photomedicine (Conference Presentation)

    Science.gov (United States)

    Dong, Yajie

    2017-02-01

    Quantum dots (QDs) have gone through a long journey before finding their ways into the display field. This talk will briefly touch on the history before trying to answer several key questions related to QDs applications in display: What are QDs? How are they made? What properties do they have and Why? How can these properties be used to improve color and efficiency of display, in either photoluminescence (PL) or electroluminescence (EL) mode? And what are the remaining challenges for QDs wide adoption in display industry? Lastly, some most recent progresses in our UCF lab at both PL and EL fronts will be highlighted. For PL, a cadmium-free perovskite-polymer composite films with exceptionally narrow emission green peaks (FWHM 20 nm) and good water and thermal stability will be reported. Together with red quantum dots or PFS/KSF phosphors as down-converters for blue LEDs, a white-light source with 95% Rec. 2020 color gamut was demonstrated [1]. For EL, red quantum dot light emitting devices (QLEDs) with record luminance of 165,000 Cd/m2 has been obtained at a current density of 1000 mA/cm2 with a low driving voltage of 5.8 V and CIE coordinates of (0.69, 0.31). [2] The potential of using these QLEDs for light sources for integrated sensing platform [3] or high efficiency, high color quality hybrid white OLED [4] will be discussed. [1] Y. N. Wang, J. He, H. Chen, J. S. Chen, R. D. Zhu, P. Ma, A. Towers, Y. Lin, A. J. Gesquiere, S. T. Wu, Y. J. Dong. Ultrastable, Highly Luminescent Organic-Inorganic Perovskite - Polymer Composite Films, Advanced Materials, accepted, (2016). [2] Y. J. Dong, J.M. Caruge, Z. Q. Zhou, C. Hamilton, Z. Popovic, J. Ho, M. Stevenson, G. Liu, V. Bulovic, M. Bawendi, P. T. Kazlas, S. Coe-Sullivan, and J. Steckel Ultra-bright, Highly Efficient, Low Roll-off Inverted Quantum-Dot Light Emitting Devices (QLEDs). SID Symp. Dig. Tech. Pap. 46, 270-273 (2015). [3] J. He, H. Chen, S. T. Wu, and Y. J. Dong, Integrated Sensing Platform Based on Quantum

  10. Multidisciplinary team care in rehabilitation

    DEFF Research Database (Denmark)

    Momsen, A.-M.; Nielsen, C.V.; Rasmussen, J.O.

    2012-01-01

    Objectives: To systematically investigate current scientific evidence about the effectiveness of multidisciplinary team rehabilitation for different health problems. Data sources: A comprehensive literature search was conducted in Cochrane, Medline, DARE, Embase, and Cinahl databases, and research...... for adults, without restrictions in terms of study population or outcomes. The most recent reviews examining a study population were selected. Data extraction: Two reviewers independently extracted information about study populations, sample sizes, study designs, rehabilitation settings, the team...

  11. SYNERGY EFFECTS IN WORK TEAMS

    OpenAIRE

    Raluca C. Zoltan

    2014-01-01

    Today’s organization increasingly utilizes all kind of teams in order to surpass their competitors through flexibility, adaptability and innovation, features which are seen to characterize the teams. For this purpose, the concept of synergy in teams’ activity is often mentioned as the prime reason for which collective work is considered to be superior comparative with individual work. But what exactly does it mean? The present paper aims to shed some light on the concept of synergy in work te...

  12. Structuring Successful Global Virtual Teams

    Science.gov (United States)

    2015-01-01

    e.g., email) to a lot (e.g., video conferencing ). Finally, global teams can vary in their level of synchronicity, or the degree to which a team’s... electronic communication. Thus, we view these types of teams as analogous enough that they can be discussed together under the overarching term of “global...emergence. Balthazard, Waldman, and Warren (2009) found that communication media that mim- ics face-to-face interactions (e.g., video conferencing

  13. The Impact of Environmental Complexity and Team Training on Team Processes and Performance in Multi-Team Environments

    National Research Council Canada - National Science Library

    Cobb, Marshall

    1999-01-01

    This study examined how manipulating the level of environmental complexity and the type of team training given to subject volunteers impacted important team process behaviors and performance outcomes...

  14. Microwave-assisted one-step synthesis of white light-emitting carbon dot suspensions

    Science.gov (United States)

    Vanessa, Hinterberger; Wenshuo, Wang; Cornelia, Damm; Simon, Wawra; Martin, Thoma; Wolfgang, Peukert

    2018-06-01

    In this contribution, we demonstrate that an aqueous solution with adjustable fluorescent color, including white light emission, can be achieved by a rapid one-step microwave synthesis method resulting in a mixture of blue-emitting carbon dots (CDs) and the yellow-emitting 2,3-diaminophenazine (DAP). Aqueous mixtures of o-phenylene-diamine (oPD) and citric acid (CA) are used as precursors. The resulting product structures are analyzed by FT-IR and NMR spectroscopy and the size of the resulting CDs is determined by atomic force microscopy to be 1.1 ± 0.3 nm. The synthesized solution exhibits two fluorescence emission peaks at 430 and 560 nm, which were found to originate from the CDs and DAP, respectively. The intensity ratio of both fluorescence peaks depends on pH, which is driven by the protonation state of DAP. In consequence, the fluorescence emission color of the CD solution can be tuned precisely and reproducibly from blue to white to yellow by careful control of the pH. Finally, at a pH level of 5.4, at which there is equal blue and yellow emission intensity, a white light emitting solution can be successfully produced in a very fast and simple synthesis procedure.

  15. Synthesis of Carbon Dots with Multiple Color Emission by Controlled Graphitization and Surface Functionalization.

    Science.gov (United States)

    Miao, Xiang; Qu, Dan; Yang, Dongxue; Nie, Bing; Zhao, Yikang; Fan, Hongyou; Sun, Zaicheng

    2018-01-01

    Multiple-color-emissive carbon dots (CDots) have potential applications in various fields such as bioimaging, light-emitting devices, and photocatalysis. The majority of the current CDots to date exhibit excitation-wavelength-dependent emissions with their maximum emission limited at the blue-light region. Here, a synthesis of multiple-color-emission CDots by controlled graphitization and surface function is reported. The CDots are synthesized through controlled thermal pyrolysis of citric acid and urea. By regulating the thermal-pyrolysis temperature and ratio of reactants, the maximum emission of the resulting CDots gradually shifts from blue to red light, covering the entire light spectrum. Specifically, the emission position of the CDots can be tuned from 430 to 630 nm through controlling the extent of graphitization and the amount of surface functional groups, COOH. The relative photoluminescence quantum yields of the CDots with blue, green, and red emission reach up to 52.6%, 35.1%, and 12.9%, respectively. Furthermore, it is demonstrated that the CDots can be uniformly dispersed into epoxy resins and be fabricated as transparent CDots/epoxy composites for multiple-color- and white-light-emitting devices. This research opens a door for developing low-cost CDots as alternative phosphors for light-emitting devices. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Teaming for Speech and Auditory Training.

    Science.gov (United States)

    Nussbaum, Debra B.; Waddy-Smith, Bettie

    1985-01-01

    The article suggests three strategies for the audiologist and speech/communication specialist to use in assisting the preschool teacher to implement student's individualized education program: (1) demonstration teaming, (2) dual teaming; and (3) rotation teaming. (CL)

  17. Photoluminescence of carbon dots from mesoporous silica

    Science.gov (United States)

    Nelson, D. K.; Razbirin, B. S.; Starukhin, A. N.; Eurov, D. A.; Kurdyukov, D. A.; Stovpiaga, E. Yu; Golubev, V. G.

    2016-09-01

    Photophysical properties of carbon dots were investigated under various excitation conditions and over a wide temperature region - from room to liquid helium temperatures. The carbon dots (CDs) were synthesized using mesoporous silica particles as a reactor and (3-aminopropyl)triethoxysilane (APTES) as a precursor. The photoluminescence spectra of CDs exhibit a strong dependence on the excitation wavelength and demonstrate a significant inhomogeneous broadening. Lowering sample temperature reveals the doublet structure of the spectra, which is associated with the vibronic structure of radiative transitions. The vibration energy ∼1200 cm-1 is close to the energy of Csbnd O stretching vibration. Long-lived phosphorescence of carbon dots with its decay time ∼0.2 s at T = 80 K was observed. The fluorescence and phosphorescence spectra are shown to be spectrally separated. The long-lived component of the emission was ascribed to optically forbidden triplet-singlet transitions. The value of the singlet-triplet splitting was found to be about 0.3 eV. Photo-induced polarization of the luminescence of carbon dots was revealed. The degree of the linear polarization is dependent on the wavelengths of both excitation and emitted light. The effect indicates a hidden anisotropy of optical dipole transitions in the dots and demonstrates the loss of the dipole orientation during the electron energy relaxation.

  18. Shape-Controlled Synthesis of All-Inorganic CsPbBr3 Perovskite Nanocrystals with Bright Blue Emission.

    Science.gov (United States)

    Liang, Zhiqin; Zhao, Suling; Xu, Zheng; Qiao, Bo; Song, Pengjie; Gao, Di; Xu, Xurong

    2016-10-26

    We developed a colloidal synthesis of CsPbBr 3 perovskite nanocrystals (NCs) at a relative low temperature (90 °C) for the bright blue emission which differs from the original green emission (∼510 nm) of CsPbBr 3 nanocubes as reported previously. Shapes of the obtained CsPbBr 3 NCs can be systematically engineered into single and lamellar-structured 0D quantum dots, as well as face-to-face stacking 2D nanoplatelets and flat-lying 2D nanosheets via tuning the amounts of oleic acid (OA) and oleylamine (OM). They exhibit sharp excitonic PL emissions at 453, 472, 449, and 452 nm, respectively. The large blue shift relative to the emission of CsPbBr 3 bulk crystal can be ascribed to the strong quantum confinement effects of these various nanoshapes. PL decay lifetimes are measured, ranging from several to tens of nanoseconds, which infers the higher ratio of exciton radiative recombination to the nonradiative trappers in the obtained CsPbBr 3 NCs. These shape-controlled CsPbBr 3 perovskite NCs with the bright blue emission will be widely used in optoelectronic applications, especially in blue LEDs which still lag behind compared to the better developed red and green LEDs.

  19. Are Teams Less Inequality Averse than Individuals?

    OpenAIRE

    He, Haoran; Villeval, Marie Claire

    2014-01-01

    We compare inequality aversion in individuals and teams by means of both within- and between-subject experimental designs, and we investigate how teams aggregate individual preferences. We find that team decisions reveal less inequality aversion than individual initial proposals in team decision-making. However, teams are no more selfish than individuals who decide in isolation. Individuals express strategically more inequality aversion in their initial proposals in team decision-making becau...

  20. Pressure and temperature effects on the third-order nonlinear optical properties in GaAs quantum dots

    International Nuclear Information System (INIS)

    Duque, C.M.; Mora-Ramos, M.E.; Duque, C.A.

    2012-01-01

    This work is used in the density matrix formalism and the effective mass approximation to study the third harmonic generation coefficient in a GaAs disc-shaped quantum dot with parabolic confinement potential. It is discussed the strong and weak confinement regime. The results show that the third harmonic generation coefficient is strongly dependent on the excitonic pair localization. The study is extended to consider effects such as hydrostatic pressure and temperature to show that it is possible to induce a blue-shift and/or red-shift on the resonant peaks of the third harmonic generation coefficient.